Strangely, back in the 80s, my Velodyne 1012 had these connections. No matter what, the sub always integrated perfectly. I can not understand why more manufacturers don't do this today.
Although our host is correct, in a semantic sense, about wanting the sound signature from the main amps, he is trading off more beneficial elements that are available when the subs are fed directly from the pre-amp. Use a high-pass filter to feed you main amps, and feed your subs directly from the pre-amp. Now, your main amps no longer have to do as much heavy lifting with bass notes. Also, your main speakers will not have to produce as much bass. This has two huge benefits, not mentioned by our host: 1) Since your main amps no longer have to deal with as much bass, your main amps will deliver cleaner, more focused voltage to your speakers. Your main amps will no longer be lugging around the heavy luggage. Your main amps will be more nimble and have an energetic stride. All amps, bar none, will benefit from this, regardless of how much power they have. 2) Your main speakers will produce less bass. That means that the cabinets for your main speakers will shake less. That will result in a significant sound improvement in the mids and highs. Voices and instruments will clearly be more focused (and voices are one sound that our brains identify very quickly). When a speaker cabinet shakes, the drivers within the cabinet shake. That distorts the mids and highs. Imagine someone holding a tiny speaker, and they are waving it around. You will clearly hear the sound from that tiny speaker changing, as it is being waved around. That is an extreme example, but illustrates the point. The same principle applies to when the speaker's cabinet shakes the drivers, due to bass from the woofers. Stop (or significantly reduce) the cabinet from shaking, you your mids and high tighten up, and just sound so much better. If your TV were to shake, you would see it. That happens with speakers, and you can hear it (even if you do not realize it -- until you end the shaking). So the advantages of less work for your main amps, plus reducing the shaking of your main speaker's cabinets, clearly outweighs the the semantic sense of having your main amp's signature sent to your subs. Our host's speakers do not work on the above the principle, and our host does not sell high-pass filters. I suspect that that influences his recommendation (and he might not even realize it, because he is going with what he knows best). So reduce the strain to your main amps, via a high-pass filter, and reduce the bass going to your main speakers (your subs will produce that bass). You will be rewarded with a significantly better sonic experience.
@@Error2username "Not going there again, Main speakers are not made to be hi passed, you compl erase the logic within the crossover in the speaker??" So what Richard Vandersteen does with his reference speakers are not made to be high passed, even though they are high passed? Richard completely erased the logic within his speaker's crossover?
It's interesting that, even though this is technically correct, when you actually do try both and optimize each, high-pass filtering doesn't necessarily sound better, let alone "significantly". It can, depending on the speaker. Of course, when Paul refers to "full range", he really does mean full range. All you're saying can easily be proven to be correct for e.g. a bookshelf or stand-mount size speaker where there is no bass driver but only a mid-bass driver whose excursion is being limited using a high-pass filter. As an aside, if main speakers can be made to shake (not referring to the use of an accelerometer, but visibly), be sure to replace them with a high-quality speaker before going to any of the trouble discussed here.
@@Error2username - Mains are not meant to be bypassed? - Erase what x/over logic? Care to elaborate? Regarding hi-passed mains, if the performance and experience is superior when hi-passed and sub supported, ... then the point is moot, ie., doesn't really matter. There is no such thing as "not made to be hi-passed". As to 𝘤𝘳𝘰𝘴𝘴𝘰𝘷𝘦𝘳 𝘭𝘰𝘨𝘪𝘤, I'm not sure what that's referring to.
@@LeonFleisherFan Quote: 't's interesting that, even though this is technically correct, when you actually do try both and optimize each, high-pass filtering doesn't necessarily sound better, let alone "significantly".' Then you are doing something wrong. Quote: 'Of course, when Paul refers to "full range", he really does mean full range.' Vandersteen's model Seven speakers are full range, more so than any of speakers in the Aspen line -- and yet every model Seven is a reference speaker that uses a high pass filter. Quote: "As an aside, if main speakers can be made to shake (not referring to the use of an accelerometer, but visibly), be sure to replace them with a high-quality speaker before going to any of the trouble discussed here." All speakers shake. There are no exceptions. Introducing an accelerometer into this discussion is an attempt to get off on a tangent. Shaking is shaking. Our ears can hear the difference with or without using an accelerometer to tell us how much a speaker cabinet is shaking. 100% of speaker cabinets shake. With high-pass filtering done correctly, 100% of those cabinets will shake less. Vandersteen's Kento and Seven speakers are available with granite bases (called Bedrock). Those granite bases reduce the vibrations in those speakers. I have heard the Model Seven speakers before and after, in the same room, with the same gear, and the same source material. And if you believe that those speakers are not high quality (quote: "replace them"), then either 1) you never heard them, 2) never read a review on them, or 3) you know zero about their inert cabinet within a cabinet construction, specifically designed to minimize shaking making its way to the mid-range and tweeter drivers.
What makes the subwoofer identifiable or localizable is not the difference in "sonic signature" between amplifiers. Rather, it's the sound output above 80 Hz coming from the sub.
@@PetraKannthe higher the frequency the more easily it can be located by ear 80Hz is a rough guide. My sub is set higher than that due to room nulls and I still can’t locate it by ear and it’s not even on the same wall as my stereo pair.
It's upwards of 200Hz that it's difficult (there's not a definitive number), depending on the filter slope and the volume it's still going to play up in the frequency range a bit. So it's crossover frequency, slope and volume that can be adjusted until it disappears. There might be some slight difference between voicing but it probably has to be rather bad before one picks up on that alone. 😄
@@michaelb9664 80 Hz has a wavelength of about 340/80 metres or just over 4 metres which is comparable to the size of the room. This long wavelength makes it difficult for our ears to discern where the low frequency is coming from left alone distinguish a stereo image. Explains why only one subwoofer is needed and its location in the listening room less important
I have a VFET Yamaha B-2 amp going to stereo subs. (L and R). The sub sound difference is very noticeable because of the sound signature of the VFETs in the amp. It's not as noticeable with other amps, but the B-2 really makes an extreme difference. If you've ever heard a B-2, then you know what I'm talking about. That's my testimony. High level inputs make a difference. It's there. Just use your ears on your own system and go with what you think sounds best. I also use the "loudness" button because it sounds better to me in my room at the moment. I'm happy enough even while I continue to periodically upgrade. Enjoy the music! That's the whole point of our stereos!
I guess where I always get lost in this is: doesn’t the subwoofer have its own ‘sonic signature’ from its own amp and speaker cable? Wouldn’t that negate any possible effect? My theory is to find a subwoofer that shares the sonic characteristics I’m looking for in my system and not worry so much about the ‘connection.’ I’ve had REL subs before, and I always felt that high-level connectivity was more about convenience than sonic improvement. Funny enough, I’ve been to PS Audio, and they have a 15” REL connected via a low-level XLR. Not trying to cause any drama here-just wanted to approach the conversation with some degree of candor. Thanks, Paul, for all your time and for sharing your knowledge with us.
Agree! - Paul just declared that ALL amplifiers have a Sound signature, then so does the Subwoofer's amplifier! As well, as you point out, the Subwoofer itself (cone material, crossover components, cabinet design) clearly have a Sound signature (as do All / Any speakers) and therefore the Sound signature of the Subwoofer as a whole far exceeds (out weighs) any so called Sound signature mimicking one is achieving via the main amplifier. Plus I might add that despite going through the main amplifier not adding a significant amount of Delay, there is 'already' inherent Delay in ALL subwoofers that 1. Is not being addressed (and is clearly audible) and 2. Going through the main only adds more Delay (even if a marginal amount more). I will add that some folks aren't as much affected by Timing/Delay as some others. And even to the point that many people actually LIKE a small amount of Delay as introduced by any Subwoofer, which has a slight "Fattening" of the bass sound. I, as have you may have gathered already, do not like that and insist that my Subwoofers are Time aligned and In-phase.
REL would not have designed their own proprietary high level wiring system for every sub they sell if it wasn't important. Yes you can make a sub disappear using low level input. It's more about volume level than any sonic signature. Bottom line, every driver in your system needs to be controlled by the exact same signal, not some fed from the main amp and some fed with the preamp. Continuity. RCA is for convenience. A fill sub at the back of the room is a different animal. Crossed extremely low to augment only the lowest frequencies the system produces. Therefore less sensitive to input to do it's job. Stereo sub's up front, absolutely exact same signal the rest of the drivers are receiving. Whether it's a REL 6 pack or 2 sub's only, they all use REL's high level wiring system.
@lexicon612 - I cordially disagree. Tried both (several different approaches) and the Rel approach wasn't to my liking / has inherent flaws for which are not to my liking and I can (and have) done better.
@@lexicon612 I certainly don’t want to challenge anyone’s enjoyment. If you like REL’s sound and believe in their philosophy, then by all means, use them. Personally, I’ve just never been able to fully rationalize their approach, and I don’t believe they monopolize the subwoofer industry with their line of thinking. There are many other great subwoofer manufacturers out there that don’t rely on high-level connections. It’s a preference-not the only way, right? Making absolute statements like ‘it’s got to be this’ or ‘it’s got to be that’ feels a bit misleading and, in my view, inaccurate. And if you’re a believer in cables, it seems odd to hook a sub up with a $30 SpeakOn cable. Where’s the synergy in that? You wouldn’t use SpeakOn cables for your mains, would you? Look, REL makes competitive products, and I have no issue with either REL or Paul’s comments. Both Paul and John are great people. I just disagree that their approach is the best and only way, as some so confidently assert. On another note, I don’t quite understand the argument about subwoofer placement and augmentation. Isn’t the whole point of a subwoofer to augment the sound and allow your mains to play full range? Whether you place your sub in the front, side, or rear of the room, it’s there to fill a gap in the low end created by the room-or to supplement mains that might not play that low. Ironically, when I visited PS Audio, I noticed their subwoofer was connected via a low-level XLR to the preamp. The sub they use, a REL Predator, doesn’t even have a high-level connection. If high-level connectivity was so crucial, I’d imagine they would have swapped it out for a REL model that offers it. Again, it seems to come down to preference and convenience. At the end of the day, I hope you’re enjoying your system-that’s all that really matters.
A parametric equalizer (DSP) in (or "only for") the subwoofer might add some milliseconds. At 70 Hz, a millisecond could be (I might be wrong; please check) around 26º of phase shift. No timing issues through high level or line level output before DSP. That phase will add to the distance (more phase difference) between the two subs and the speakers.
The basic concept of adding a sub-woofer to a sound system is to enhance the low frequencies without coloring the vocal tonality, and without depleting any low frequencies due to phase incoherence. Yet either a sub-woofer or a hifi system has its own low pass filter that would create a phase shift relatively, so selecting a correct phase-shift compensation setting on a sub is important in blending it smoothly into the system
I would argue that my speaker woofers (high efficiency) have no semblance to any subwoofer driver and therefore would not benefit from any additional signature from my triamp woofer tube amp. I, in fact get best results from running the electronic crossover for all speakers at preamp line level. I match amplifier and speaker to get the best synergy. Maybe Chris Brunhaver has something more compelling in the upcoming PS Audio subwoofer but that remains to be seen and heard. Speaker level inputs have the highest distortion AND (delayed) artifacts from the woofer EMF. We can pick our poison depending on if the sub high level input impedance matches with a transformer/buffer or resistor bridge/buffer. The next hurdle is if the sub has dsp which means unavoidable delay. Too many reasons not to use the speaker level inputs.
and amp or dac has almost no delay, but the dsp in an amp have a delay and some quite a lot. tens of milliseconds. and some active speakers with dsp had so much delay it causes lip sync errors in movies. that is why i recommend have a passive subwoofer, just a driver in a box. and now you can have the dsp in the signal path before the conversion to analog. so for digital sources there is no extra conversion with the dsp. i god one of those type of dsp systems, and i got the chance to switch amps around, two different stereo power amps, tried them on mains speakers and then the subwoofers. one is more powerful and more expensive so i wanted it on my subwoofers, but they sounded better on my small main speaker so now my subwoofers have the smaller amp on them, subwoofer amps are les critical of amplification in my case.
To an extent, I always thought of the preamp as the meat and the amp the spices. But definitely if you’re not happy with your amp try changing out your preamp or CD/Digital source first before exploring a new amp.
The timing of the signal reaching your ears is the important one. That is why it's crucial to time align the speakers and the subs. Could be through conversion of distance from LP or through some DSP and a measurement microphone, either in the receiver or the sub itself. Sound that is not time aligned can cause all kind of issues, from cancellations to distortions.
@@razisn Tow subs (stereo) in a good system could (maybe should) also reproduce higher frequencies even if speakers can go very low, because room maters. Any speaker far from the wall (1 m or more is very usual) will produce partial cancellation with the front wall (behind the speaker) at quarter wave length: 85 Hz in this case (without subs 100 Hz and 60 Hz will be higher). Further away, let's say 1,5 m, the output will drop around 57 Hz and increase over and bellow that frequency; room will of course mess with everything. The subs in stereo will help to fill that cancellation and level the output of the main speakers. These two subs with a good setup would disappear even with a crossover as high. Only one sub even with a very low crossover won't disappear, because even if it might be impossible to localize, we will fill the asymmetry of pressure in the rooms (we have two ears) as the measurements do.
@@PSA78 True, but you don't fill the null perfectly. Timing in my experience helps. There is no downside to time aligning subwoofers. In many setups it isn't that difficult either.
@@OG2978-g7x Though they can have the same effect, time and phase is two different things (and it can get rather confusing depending on if it's amplifier, driver, speaker or listening in the room that's discussed, as they rarely align and also move around), and it's phase at the listening position from and in the room that creates either two equal or two opposite waves (or something in between) for really low frequencies. Higher frequencies reflected off surfaces in the room can create reverb or smearing of the sound (long enough and we'll hear it as echo). It can help when building entire speakers to move the acoustic centre (time align) as both filters and box changes the phase, but that's a different story. In the end, if it measures relatively flat and it sounds okay then the sub is okay. The old 'crawl tests' works as well.
I thought the sub out was limited or filtered to lower bass frequencies which cuts off some of the higher bass and the rest of the frequency spectrum but is needed for accurate full sound reproduction?
With regard to the subwoofer's high-level inputs, the question also arises as to whether the same cables should be used as for the other loudspeakers? Or is it sufficient to use simple (and inexpensive) cables, as high power levels are not transmitted there?
The same exact cables going to your mains is exactly what should feed your sub's. Cabling always matters. High power is going to each sub, just not being utilized by the sub. The sub is extracting it's signal from the high power signal coming from the main amp.
@@lexicon612 Comparatively high voltage, but not high power. Current to the sub is very small. There is no point in using heavy speaker cable for this.
How about when the sub runs off the pre amp? Seems like the amp in the sub and the speaker amp would get the signal at the same time. I always thought ( probably inaccuratly) of the high level inputs as a lessor quality connection. Like you'd use that if you didn't have a " sub out". Seem many of the cheaper subs have these and some higher end subs don't. Not saying they are inferior... just the opinion I formed seeing the high level in on only cheaper subs. My SVS sub doesn't have a high level input.
Either way the sound from the pre-amp has to go through an amplifier whether it be your main amp or sub amp. so I'm not buying the timing issue. Also the main sound signatures comes from the pre-amp to start with and the sub usually doesn't play above 80 Hz., and why go through 2 amps it's going to change on the sub amp anyway, so I'm not buying that either. Also my mains are full range and my sub low pass is set to 40 Hz. that's where my mains roll off. So it sounds like its coming from the mains at times it sounds like its coming for the speaker on the other side of the room, depending on the recording. So do what ever floats your boat provided you have the settings correct to your mains and room.
I’ve tried the two connecting options [sub out vs speaker out on the amp] and I wasn’t able to hear a difference. The only minor issue that I’ve had with a small number of dedicated sub outs is lack of desirable sound level.
Is there any difference between connecting the speaker level from the amp to the sub amp vs connecting the speakers to the sub amp? This would require a much shorter cable and would be more neat.
@@jelugo77 PS Audio designs their amp's with 4 speaker outputs. I own the S-300 2 channel amp. 4 speaker outputs. The sole purpose of doing this is to use the exact same cables for your mains, for your stereo sub's, conveniently. Direct connection from the amp's outputs to the sub's. Why would you want an entire speaker in the signal path to your Sub? Saving a few bucks on cabling is not something I would prioritize, or neatness for that matter. imho.
If you have transitioned to digital only music, better is to cross-over the subwoofer through a DSP and get everything fine-tuned on phase and frequency response also allowing smaller stereo speakers to not cause excursion limit distortion, base port distortion, intermodulation distortion and waste good power when they try to play the sub bass you purchased the subwoofer to do. This issue can become very apparent when playing loud.
Equalization is great (I use it for room modes) but it's not free. A high pass filter on mains is a compromise, some benefits and some problems (so I have been told and read). Preringing or phase shift of higher frequencies; I suppose that we should choose one or another, no free lunch. If the speaker can't handle a full range signal, the speaker or the setup (distance and output level regardless of room size) are the problem. If the setup isn't right and we don't want (or can't) to change it, the solution you explained (frequently used in home cinema) is very useful.
@@Jorge-Fernandez-Lopez The type of filter will determine the behavior of it. I would never use a passive high-pass filter for stereo speakers and that's Paul's point also. However, I have found active filtering to be superior when well optimized and when you have an active filtering, it makes sense also to high-pass filter the stereo speakers in a system with smaller speakers and a subwoofer. Especially if you play digital music only, it makes a lot of sense to use DSP for all cross-over filtering and get it optimized on phase and frequency response.
@@ThinkingBetter I do use parametric equalization. However, I must be very careful to avoid clipping with some albums (modern ones) even if I only cut down frequencies. Which mathematical arrays avoid pre-ringing, phase shift or clipping (when reducing output without dynamic range limitation) ? Which DAC could we use with a 4 outputs stereo digital DSP processed channels before the amplifier in a HiFi setup other than built-in DACs in MiniDSP or Home Theater amplifiers?
@@ThinkingBetter I did a null test with Audacity with pink noise. I see phase shift so a suppose that's not a minimum phase filter that causes pre-ringing. The high pass filter 12 dB/octave at 80 Hz produce still -20 dB distortion-phase-shift after 300 Hz and -40 dB at 1000 Hz. The 24 dB/octave filter is worse. A high pass filter a 50 Hz, lowers -20 dB at 300 Hz.
The Trials and Tribulations of a Sub/Woofer My Pair of Apogee 18” Sub/Woofers and Crest 8001 Power Amp When i Listen to The Remaster of The YES Fragile Album Chris Squire and His Rickenbacker Bass Is Right Up Front Where It Should Be It’s Like YES is In My House 🏠 or Jaco Pastorius First Album Produced by Drummer Bobby Colomby The Bass Guitar and Bass Drum Is Up Front and Mixed That Way As Well as Chris Squires Bass in YES Pauls Personal Taste Is Totally Subjective ….Sometimes You Just Got To Turn Up The Bass …..Aretha Franklin Rock Steady With Bootsy Collins on a 5 String Bass or Larry Graham and Graham Central Station or Larry Graham When He Was In Sly and The Family Stone The Bass is Mixed Up Front or Stanley Clark in Weather Report The Bass Tracks are Recorded At Maximum Saturation By Producers Who Understood That The Bass Guitar Is Not a Musical Instrument That’s Buried In The Background So Folks Turn It Up and I Regret That I Have But Only One Pair Of Ears 👂 To Give To My Music 🎼 My Ears Are Not Like They Used to Be Yet Everyone’s Ears 👂 😮 are Different So Play Your Music With The Bass Cranked Up or Not Some Folks Want To Hear The Music 🎶 😮 Others Want To Feel and Hear The Music 🎵 Side Note: Back in The Day of Ampex 1” 456 Grand Master Tape The Producers of Bands That Show Cased The Bass Guitar 🎸 Where Having Trouble With The Low Frequencies Bleeding 🩸 Into The Other Tracks So These Producers Would Lay The Bass Track at Ether Edge of The Tape and Leave The Next Track Open So When The Tape Was Fully Saturated With Low Frequencies The Frequencies On One End Of The Tape Would Just Fall Off and Since There Was No Track Next To The Bass Track It Would Bleed Into a Open Track This Technique was Used By Some of The Top Recording Producers Back When Yet I Can Not Substantiate This…..😮 Because Most of These Producers Have Since Passed On and Took Their Technique With Them P.S. When is Paul Going to Go Paperless 😮
Im afraid I find the REL approach to subwoofer integration a little passé these days and while there might be some logic to using high speaker outputs, if you have no existing pre or sub out, I don’t find sonically that bass loses any amplifier signature by using the dedicated outputs. Subwoofer bass timing and all aspects of integration are easily manipulated by modern subwoofer electronics from the likes of SVS and Arendal with comprehensive controls to adjust and fine tune every aspect of integration to your system amplification and the listening room. REL and others have been slow to adapt the electronics in their subwoofer technology and today are less capable because of that.
Room correction and the like should not be done on the sub, but upstream. Sub dsp delays are what necessitate timing correction upstream too. They are causing problems with the sub dsp and then you need to correct for those…
@@razisn I do equalize upstream (the files) for that very same reason. DSP equalization inside (or only for) the subwoofer can cause a important delay.
@I could not agree more, correct the room. But that doesn’t mean that corrections like level, slope, phase, bypass filtering, eq and lots more fine tuning controls shouldn’t be a part of the subwoofer’s offering for the sub-optimal listening conditions many face.
If we agree that all amps have a signature, then we must also agree that the amps used in active subs also have one. This kinda dwarfs the whole premise of "carrying through" the sound of your main amp,whether connected in either high level or low level,especially when the input impedance is so high (on "high level") that very little of the main amps sound characteristics are able to get through. It's not a formula that i buy into myself.
"kinda dwarves". Well it means it could, but you would have to produce evidence of any specific combination, but, in fact, as Paul said, the more you put the signature of the amp into the equation, those closer you get and that does seem to be reasonable. Have you tried it or are you a theoretical physician?
i where in the same boat as you for years, until i got the ability to adjust for delay in mains speakers and parametric equalization, and then having two subwoofers in stereo. just saying how much better it can sound in the future with experience.
Do not agree - Paul just declared that ALL amplifiers have a Sound signature, then so does the Subwoofer's amplifier! As well the Subwoofer itself (cone material, crossover components, cabinet design) clearly have a Sound signature (as do All / Any speakers) and therefore the Sound signature of the Subwoofer as a whole far exceeds (out weighs) any so called Sound signature mimicking one is achieving via the main amplifier. Plus I might add that despite going through the main amplifier not adding a significant amount of Delay, there is 'already' inherent Delay in ALL subwoofers that 1. Is not being addressed (and is clearly audible) and 2. Going through the main only adds more Delay (even if a marginal amount more). I will add that some folks aren't as much affected by Timing/Delay as some others. And even to the point that many people actually LIKE a small amount of Delay as introduced by any Subwoofer, which has a slight "Fattening" of the bass sound. I, as you may have gathered already, do not like that and insist that my Subwoofers are Time aligned and In-phase.
What's with the db Drive box in the lower left hand corner? I thought we were engineering woofers? Not just buying mediocre car audio and putting it in a house 🤔
So you take a line level signal, amplify it, then convert that high level back into low level only to be amplified again and you say that it sounds better that way? That has to be the worst advice I’ve ever heard……
Powered Sub's are perfectly capable of extracting the amp's signature from a high level input. Then its amp adds whatever it adds. Every driver in any sound system should all be receiving the same signal. 50 year professional's do not give bad advise. If you choose not to hear him, that's on you. Figure out why he's right. Heck, call REL they will tell you the same thing. This is not an opinion thing.
What is a sonic signature? Skewed frequency response? Distortion? Phase shift? Or some unquantifiable magic? A high fidelity amplifier doesn’t change the signal because it will have a flat response and vanishingly low distortion so where is the ‘signature’? If all amps have a sonic signature that will also apply to the active subs inbuilt amplification so now we’re talking about even further deviations from the source material. So do we now need amplifier and sub ‘synergy’? What nonsense. If a sub is audible it simply isn’t set up properly, nothing to do with high level or low level inputs or your amplifiers ‘sonic signature’ not getting through. The only signature is from the transducers and the room. Some audiophiles want to hear the music not some distorted representation of it while believing in magic. Some of us have a real grasp of engineering. This channel could be a source of real info, but it just keeps feeding the cult of audiophelia nonsense from 40 years ago. Of course I’ve seen some PS Audio gear with a permanent inbuilt +7db boost in the bass so yeah that’s a signature right there - but that isn’t fidelity.
Agreed, amplifiers have sonic characteristics, or signatures. In the 𝘴𝘵𝘳𝘢𝘪𝘨𝘩𝘵 𝘸𝘪𝘳𝘦 𝘸𝘪𝘵𝘩 𝘨𝘢𝘪𝘯 landscape of hifi, ... where is the exception for placing amps in series? (feeding an amplifier with another amplifier?) Of course, it's a convenience feature. In a current kludge, I'm operating active monitors fed by a throwaway cheap receiver in one system. One of my first hifi subs had high level inputs (~35yrs ago), for connectivity convenience. I would like to know the specific electronic advantage that is imparted on the second amplifier's sonics. How can a quality subwoofer amplifier be superior in performance, when fed high level rather than line level? There's just signal voltage, drive current ... Temporal variations, plus distortion nonlinearities. - What's the 𝘫𝘦 𝘯𝘦 𝘴𝘢𝘪𝘴 𝘲𝘶𝘰𝘪 imparted onto the second amplifier's output?
Strangely, back in the 80s, my Velodyne 1012 had these connections. No matter what, the sub always integrated perfectly. I can not understand why more manufacturers don't do this today.
Although our host is correct, in a semantic sense, about wanting the sound signature from the main amps, he is trading off more beneficial elements that are available when the subs are fed directly from the pre-amp.
Use a high-pass filter to feed you main amps, and feed your subs directly from the pre-amp.
Now, your main amps no longer have to do as much heavy lifting with bass notes. Also, your main speakers will not have to produce as much bass.
This has two huge benefits, not mentioned by our host:
1) Since your main amps no longer have to deal with as much bass, your main amps will deliver cleaner, more focused voltage to your speakers. Your main amps will no longer be lugging around the heavy luggage. Your main amps will be more nimble and have an energetic stride. All amps, bar none, will benefit from this, regardless of how much power they have.
2) Your main speakers will produce less bass. That means that the cabinets for your main speakers will shake less. That will result in a significant sound improvement in the mids and highs. Voices and instruments will clearly be more focused (and voices are one sound that our brains identify very quickly).
When a speaker cabinet shakes, the drivers within the cabinet shake. That distorts the mids and highs.
Imagine someone holding a tiny speaker, and they are waving it around. You will clearly hear the sound from that tiny speaker changing, as it is being waved around. That is an extreme example, but illustrates the point.
The same principle applies to when the speaker's cabinet shakes the drivers, due to bass from the woofers. Stop (or significantly reduce) the cabinet from shaking, you your mids and high tighten up, and just sound so much better.
If your TV were to shake, you would see it. That happens with speakers, and you can hear it (even if you do not realize it -- until you end the shaking).
So the advantages of less work for your main amps, plus reducing the shaking of your main speaker's cabinets, clearly outweighs the the semantic sense of having your main amp's signature sent to your subs.
Our host's speakers do not work on the above the principle, and our host does not sell high-pass filters. I suspect that that influences his recommendation (and he might not even realize it, because he is going with what he knows best).
So reduce the strain to your main amps, via a high-pass filter, and reduce the bass going to your main speakers (your subs will produce that bass). You will be rewarded with a significantly better sonic experience.
Not going there again, Main speakers are not made to be hi passed, you compl erase the logic within the crossover in the speaker??
@@Error2username "Not going there again, Main speakers are not made to be hi passed, you compl erase the logic within the crossover in the speaker??"
So what Richard Vandersteen does with his reference speakers are not made to be high passed, even though they are high passed?
Richard completely erased the logic within his speaker's crossover?
It's interesting that, even though this is technically correct, when you actually do try both and optimize each, high-pass filtering doesn't necessarily sound better, let alone "significantly". It can, depending on the speaker. Of course, when Paul refers to "full range", he really does mean full range. All you're saying can easily be proven to be correct for e.g. a bookshelf or stand-mount size speaker where there is no bass driver but only a mid-bass driver whose excursion is being limited using a high-pass filter. As an aside, if main speakers can be made to shake (not referring to the use of an accelerometer, but visibly), be sure to replace them with a high-quality speaker before going to any of the trouble discussed here.
@@Error2username
- Mains are not meant to be bypassed?
- Erase what x/over logic?
Care to elaborate?
Regarding hi-passed mains, if the performance and experience is superior when hi-passed and sub supported, ... then the point is moot, ie., doesn't really matter.
There is no such thing as "not made to be hi-passed".
As to 𝘤𝘳𝘰𝘴𝘴𝘰𝘷𝘦𝘳 𝘭𝘰𝘨𝘪𝘤, I'm not sure what that's referring to.
@@LeonFleisherFan Quote:
't's interesting that, even though this is technically correct, when you actually do try both and optimize each, high-pass filtering doesn't necessarily sound better, let alone "significantly".'
Then you are doing something wrong.
Quote:
'Of course, when Paul refers to "full range", he really does mean full range.'
Vandersteen's model Seven speakers are full range, more so than any of speakers in the Aspen line -- and yet every model Seven is a reference speaker that uses a high pass filter.
Quote:
"As an aside, if main speakers can be made to shake (not referring to the use of an accelerometer, but visibly), be sure to replace them with a high-quality speaker before going to any of the trouble discussed here."
All speakers shake. There are no exceptions.
Introducing an accelerometer into this discussion is an attempt to get off on a tangent. Shaking is shaking. Our ears can hear the difference with or without using an accelerometer to tell us how much a speaker cabinet is shaking. 100% of speaker cabinets shake. With high-pass filtering done correctly, 100% of those cabinets will shake less.
Vandersteen's Kento and Seven speakers are available with granite bases (called Bedrock). Those granite bases reduce the vibrations in those speakers. I have heard the Model Seven speakers before and after, in the same room, with the same gear, and the same source material. And if you believe that those speakers are not high quality (quote: "replace them"), then either 1) you never heard them, 2) never read a review on them, or 3) you know zero about their inert cabinet within a cabinet construction, specifically designed to minimize shaking making its way to the mid-range and tweeter drivers.
What makes the subwoofer identifiable or localizable is not the difference in "sonic signature" between amplifiers. Rather, it's the sound output above 80 Hz coming from the sub.
Why 80 Hz?
@@PetraKannthe higher the frequency the more easily it can be located by ear 80Hz is a rough guide. My sub is set higher than that due to room nulls and I still can’t locate it by ear and it’s not even on the same wall as my stereo pair.
It's upwards of 200Hz that it's difficult (there's not a definitive number), depending on the filter slope and the volume it's still going to play up in the frequency range a bit. So it's crossover frequency, slope and volume that can be adjusted until it disappears.
There might be some slight difference between voicing but it probably has to be rather bad before one picks up on that alone. 😄
@@michaelb9664 80 Hz has a wavelength of about 340/80 metres or just over 4 metres which is comparable to the size of the room.
This long wavelength makes it difficult for our ears to discern where the low frequency is coming from left alone distinguish a stereo image. Explains why only one subwoofer is needed and its location in the listening room less important
I would agree but, have fun. It’s about loving the music. All amps have a signature, except mine. lol
I have a VFET Yamaha B-2 amp going to stereo subs. (L and R). The sub sound difference is very noticeable because of the sound signature of the VFETs in the amp.
It's not as noticeable with other amps, but the B-2 really makes an extreme difference. If you've ever heard a B-2, then you know what I'm talking about.
That's my testimony. High level inputs make a difference. It's there. Just use your ears on your own system and go with what you think sounds best.
I also use the "loudness" button because it sounds better to me in my room at the moment. I'm happy enough even while I continue to periodically upgrade. Enjoy the music! That's the whole point of our stereos!
A wise man once said that the speed of sound travels at the speed of light through an audio cable.
I guess where I always get lost in this is: doesn’t the subwoofer have its own ‘sonic signature’ from its own amp and speaker cable? Wouldn’t that negate any possible effect? My theory is to find a subwoofer that shares the sonic characteristics I’m looking for in my system and not worry so much about the ‘connection.’ I’ve had REL subs before, and I always felt that high-level connectivity was more about convenience than sonic improvement. Funny enough, I’ve been to PS Audio, and they have a 15” REL connected via a low-level XLR. Not trying to cause any drama here-just wanted to approach the conversation with some degree of candor. Thanks, Paul, for all your time and for sharing your knowledge with us.
Agree! - Paul just declared that ALL amplifiers have a Sound signature, then so does the Subwoofer's amplifier! As well, as you point out, the Subwoofer itself (cone material, crossover components, cabinet design) clearly have a Sound signature (as do All / Any speakers) and therefore the Sound signature of the Subwoofer as a whole far exceeds (out weighs) any so called Sound signature mimicking one is achieving via the main amplifier. Plus I might add that despite going through the main amplifier not adding a significant amount of Delay, there is 'already' inherent Delay in ALL subwoofers that 1. Is not being addressed (and is clearly audible) and 2. Going through the main only adds more Delay (even if a marginal amount more). I will add that some folks aren't as much affected by Timing/Delay as some others. And even to the point that many people actually LIKE a small amount of Delay as introduced by any Subwoofer, which has a slight "Fattening" of the bass sound. I, as have you may have gathered already, do not like that and insist that my Subwoofers are Time aligned and In-phase.
REL would not have designed their own proprietary high level wiring system for every sub they sell if it wasn't important. Yes you can make a sub disappear using low level input. It's more about volume level than any sonic signature. Bottom line, every driver in your system needs to be controlled by the exact same signal, not some fed from the main amp and some fed with the preamp. Continuity. RCA is for convenience. A fill sub at the back of the room is a different animal. Crossed extremely low to augment only the lowest frequencies the system produces. Therefore less sensitive to input to do it's job. Stereo sub's up front, absolutely exact same signal the rest of the drivers are receiving. Whether it's a REL 6 pack or 2 sub's only, they all use REL's high level wiring system.
@lexicon612 - I cordially disagree. Tried both (several different approaches) and the Rel approach wasn't to my liking / has inherent flaws for which are not to my liking and I can (and have) done better.
@@lexicon612 I certainly don’t want to challenge anyone’s enjoyment. If you like REL’s sound and believe in their philosophy, then by all means, use them. Personally, I’ve just never been able to fully rationalize their approach, and I don’t believe they monopolize the subwoofer industry with their line of thinking. There are many other great subwoofer manufacturers out there that don’t rely on high-level connections. It’s a preference-not the only way, right?
Making absolute statements like ‘it’s got to be this’ or ‘it’s got to be that’ feels a bit misleading and, in my view, inaccurate. And if you’re a believer in cables, it seems odd to hook a sub up with a $30 SpeakOn cable. Where’s the synergy in that? You wouldn’t use SpeakOn cables for your mains, would you?
Look, REL makes competitive products, and I have no issue with either REL or Paul’s comments. Both Paul and John are great people. I just disagree that their approach is the best and only way, as some so confidently assert.
On another note, I don’t quite understand the argument about subwoofer placement and augmentation. Isn’t the whole point of a subwoofer to augment the sound and allow your mains to play full range? Whether you place your sub in the front, side, or rear of the room, it’s there to fill a gap in the low end created by the room-or to supplement mains that might not play that low.
Ironically, when I visited PS Audio, I noticed their subwoofer was connected via a low-level XLR to the preamp. The sub they use, a REL Predator, doesn’t even have a high-level connection. If high-level connectivity was so crucial, I’d imagine they would have swapped it out for a REL model that offers it. Again, it seems to come down to preference and convenience.
At the end of the day, I hope you’re enjoying your system-that’s all that really matters.
A great answer, Paul.
A parametric equalizer (DSP) in (or "only for") the subwoofer might add some milliseconds. At 70 Hz, a millisecond could be (I might be wrong; please check) around 26º of phase shift. No timing issues through high level or line level output before DSP. That phase will add to the distance (more phase difference) between the two subs and the speakers.
The basic concept of adding a sub-woofer to a sound system is to enhance the low frequencies without coloring the vocal tonality, and without depleting any low frequencies due to phase incoherence. Yet either a sub-woofer or a hifi system has its own low pass filter that would create a phase shift relatively, so selecting a correct phase-shift compensation setting on a sub is important in blending it smoothly into the system
I would argue that my speaker woofers (high efficiency) have no semblance to any subwoofer driver and therefore would not benefit from any additional signature from my triamp woofer tube amp. I, in fact get best results from running the electronic crossover for all speakers at preamp line level. I match amplifier and speaker to get the best synergy. Maybe Chris Brunhaver has something more compelling in the upcoming PS Audio subwoofer but that remains to be seen and heard. Speaker level inputs have the highest distortion AND (delayed) artifacts from the woofer EMF. We can pick our poison depending on if the sub high level input impedance matches with a transformer/buffer or resistor bridge/buffer. The next hurdle is if the sub has dsp which means unavoidable delay. Too many reasons not to use the speaker level inputs.
Interesting, thanks Paul! 😊
and amp or dac has almost no delay, but the dsp in an amp have a delay and some quite a lot. tens of milliseconds. and some active speakers with dsp had so much delay it causes lip sync errors in movies.
that is why i recommend have a passive subwoofer, just a driver in a box. and now you can have the dsp in the signal path before the conversion to analog. so for digital sources there is no extra conversion with the dsp.
i god one of those type of dsp systems, and i got the chance to switch amps around, two different stereo power amps, tried them on mains speakers and then the subwoofers. one is more powerful and more expensive so i wanted it on my subwoofers, but they sounded better on my small main speaker so now my subwoofers have the smaller amp on them, subwoofer amps are les critical of amplification in my case.
The main sound signature of an amp is in the pre-amp. That will still get delivered to a sub via low level.
To an extent, I always thought of the preamp as the meat and the amp the spices. But definitely if you’re not happy with your amp try changing out your preamp or CD/Digital source first before exploring a new amp.
The timing of the signal reaching your ears is the important one. That is why it's crucial to time align the speakers and the subs. Could be through conversion of distance from LP or through some DSP and a measurement microphone, either in the receiver or the sub itself. Sound that is not time aligned can cause all kind of issues, from cancellations to distortions.
Quite irrelevant for frequencies as low as a sub would be called to reproduce in a good system, which would be lower than 50Hz
@@razisn Tow subs (stereo) in a good system could (maybe should) also reproduce higher frequencies even if speakers can go very low, because room maters. Any speaker far from the wall (1 m or more is very usual) will produce partial cancellation with the front wall (behind the speaker) at quarter wave length: 85 Hz in this case (without subs 100 Hz and 60 Hz will be higher). Further away, let's say 1,5 m, the output will drop around 57 Hz and increase over and bellow that frequency; room will of course mess with everything. The subs in stereo will help to fill that cancellation and level the output of the main speakers. These two subs with a good setup would disappear even with a crossover as high. Only one sub even with a very low crossover won't disappear, because even if it might be impossible to localize, we will fill the asymmetry of pressure in the rooms (we have two ears) as the measurements do.
@@OG2978-g7x A subwoofer is typically added because there is a null.
@@PSA78 True, but you don't fill the null perfectly. Timing in my experience helps. There is no downside to time aligning subwoofers. In many setups it isn't that difficult either.
@@OG2978-g7x Though they can have the same effect, time and phase is two different things (and it can get rather confusing depending on if it's amplifier, driver, speaker or listening in the room that's discussed, as they rarely align and also move around), and it's phase at the listening position from and in the room that creates either two equal or two opposite waves (or something in between) for really low frequencies.
Higher frequencies reflected off surfaces in the room can create reverb or smearing of the sound (long enough and we'll hear it as echo). It can help when building entire speakers to move the acoustic centre (time align) as both filters and box changes the phase, but that's a different story.
In the end, if it measures relatively flat and it sounds okay then the sub is okay. The old 'crawl tests' works as well.
That’s how I run my pair of Yamaha subs on my two Chanel System and yes they disappear exactly the way you say 😊
I thought the sub out was limited or filtered to lower bass frequencies which cuts off some of the higher bass and the rest of the frequency spectrum but is needed for accurate full sound reproduction?
The best thing I ever did with my system is connecting the sub this way. Night and day difference.
With regard to the subwoofer's high-level inputs, the question also arises as to whether the same cables should be used as for the other loudspeakers? Or is it sufficient to use simple (and inexpensive) cables, as high power levels are not transmitted there?
I use 2 high lvl input active class ab 10" subwoofers with cheap cables connected from the speakers, the sound is very great for me
The same exact cables going to your mains is exactly what should feed your sub's. Cabling always matters. High power is going to each sub, just not being utilized by the sub. The sub is extracting it's signal from the high power signal coming from the main amp.
@@lexicon612 Comparatively high voltage, but not high power. Current to the sub is very small. There is no point in using heavy speaker cable for this.
How about when the sub runs off the pre amp? Seems like the amp in the sub and the speaker amp would get the signal at the same time.
I always thought ( probably inaccuratly) of the high level inputs as a lessor quality connection. Like you'd use that if you didn't have a " sub out".
Seem many of the cheaper subs have these and some higher end subs don't.
Not saying they are inferior... just the opinion I formed seeing the high level in on only cheaper subs. My SVS sub doesn't have a high level input.
Either way the sound from the pre-amp has to go through an amplifier whether it be your main amp or sub amp. so I'm not buying the timing issue. Also the main sound signatures comes from the pre-amp to start with and the sub usually doesn't play above 80 Hz., and why go through 2 amps it's going to change on the sub amp anyway, so I'm not buying that either. Also my mains are full range and my sub low pass is set to 40 Hz. that's where my mains roll off. So it sounds like its coming from the mains at times it sounds like its coming for the speaker on the other side of the room, depending on the recording. So do what ever floats your boat provided you have the settings correct to your mains and room.
I’ve tried the two connecting options [sub out vs speaker out on the amp] and I wasn’t able to hear a difference. The only minor issue that I’ve had with a small number of dedicated sub outs is lack of desirable sound level.
Is there any difference between connecting the speaker level from the amp to the sub amp vs connecting the speakers to the sub amp? This would require a much shorter cable and would be more neat.
just to be clear - power amp to speakers - speakers to sub amp speaker level.
@@jelugo77 PS Audio designs their amp's with 4 speaker outputs. I own the S-300 2 channel amp. 4 speaker outputs. The sole purpose of doing this is to use the exact same cables for your mains, for your stereo sub's, conveniently. Direct connection from the amp's outputs to the sub's. Why would you want an entire speaker in the signal path to your Sub? Saving a few bucks on cabling is not something I would prioritize, or neatness for that matter. imho.
If you have transitioned to digital only music, better is to cross-over the subwoofer through a DSP and get everything fine-tuned on phase and frequency response also allowing smaller stereo speakers to not cause excursion limit distortion, base port distortion, intermodulation distortion and waste good power when they try to play the sub bass you purchased the subwoofer to do. This issue can become very apparent when playing loud.
Equalization is great (I use it for room modes) but it's not free. A high pass filter on mains is a compromise, some benefits and some problems (so I have been told and read). Preringing or phase shift of higher frequencies; I suppose that we should choose one or another, no free lunch. If the speaker can't handle a full range signal, the speaker or the setup (distance and output level regardless of room size) are the problem. If the setup isn't right and we don't want (or can't) to change it, the solution you explained (frequently used in home cinema) is very useful.
@@Jorge-Fernandez-Lopez The type of filter will determine the behavior of it. I would never use a passive high-pass filter for stereo speakers and that's Paul's point also. However, I have found active filtering to be superior when well optimized and when you have an active filtering, it makes sense also to high-pass filter the stereo speakers in a system with smaller speakers and a subwoofer. Especially if you play digital music only, it makes a lot of sense to use DSP for all cross-over filtering and get it optimized on phase and frequency response.
@@ThinkingBetter I do use parametric equalization. However, I must be very careful to avoid clipping with some albums (modern ones) even if I only cut down frequencies. Which mathematical arrays avoid pre-ringing, phase shift or clipping (when reducing output without dynamic range limitation) ?
Which DAC could we use with a 4 outputs stereo digital DSP processed channels before the amplifier in a HiFi setup other than built-in DACs in MiniDSP or Home Theater amplifiers?
@@ThinkingBetter I did a null test with Audacity with pink noise. I see phase shift so a suppose that's not a minimum phase filter that causes pre-ringing. The high pass filter 12 dB/octave at 80 Hz produce still -20 dB distortion-phase-shift after 300 Hz and -40 dB at 1000 Hz. The 24 dB/octave filter is worse. A high pass filter a 50 Hz, lowers -20 dB at 300 Hz.
The Trials and
Tribulations of a
Sub/Woofer
My Pair of Apogee
18” Sub/Woofers and
Crest 8001 Power Amp
When i Listen to
The Remaster
of The YES Fragile Album
Chris Squire and His
Rickenbacker Bass
Is Right Up Front
Where It Should Be
It’s Like YES is In
My House 🏠
or Jaco Pastorius
First Album Produced by
Drummer
Bobby Colomby
The Bass Guitar and
Bass Drum
Is Up Front and
Mixed That Way
As Well as
Chris Squires Bass in
YES
Pauls Personal Taste
Is Totally Subjective
….Sometimes You Just Got To Turn Up
The Bass
…..Aretha Franklin
Rock Steady With
Bootsy Collins on a
5 String Bass or
Larry Graham and
Graham Central Station
or Larry Graham When He
Was In Sly and
The Family Stone
The Bass is
Mixed Up Front or
Stanley Clark in
Weather Report
The Bass Tracks are
Recorded At Maximum Saturation By Producers
Who Understood That
The Bass Guitar Is Not a Musical Instrument That’s Buried In The Background
So Folks Turn It Up
and I Regret That I Have
But Only One Pair Of Ears
👂 To Give To My
Music 🎼
My Ears Are Not Like They Used to Be Yet
Everyone’s Ears 👂 😮
are Different So
Play Your Music
With The Bass Cranked Up or Not
Some Folks Want To
Hear The Music 🎶 😮
Others Want To
Feel and Hear
The Music 🎵
Side Note:
Back in The Day of
Ampex 1” 456 Grand
Master Tape
The Producers of
Bands That Show Cased
The Bass Guitar 🎸 Where Having Trouble With The Low Frequencies Bleeding 🩸 Into The Other Tracks
So These Producers Would Lay The Bass Track at Ether Edge of
The Tape and Leave The Next Track Open So When The Tape Was Fully Saturated With Low Frequencies The Frequencies On One End Of The Tape Would Just Fall Off and Since There Was No Track Next To The Bass Track It Would Bleed Into a Open Track
This Technique was Used By
Some of The Top
Recording Producers Back When Yet
I Can Not Substantiate
This…..😮
Because Most of
These Producers Have Since Passed On
and Took Their
Technique With Them
P.S.
When is Paul Going to Go
Paperless 😮
Im afraid I find the REL approach to subwoofer integration a little passé these days and while there might be some logic to using high speaker outputs, if you have no existing pre or sub out, I don’t find sonically that bass loses any amplifier signature by using the dedicated outputs. Subwoofer bass timing and all aspects of integration are easily manipulated by modern subwoofer electronics from the likes of SVS and Arendal with comprehensive controls to adjust and fine tune every aspect of integration to your system amplification and the listening room. REL and others have been slow to adapt the electronics in their subwoofer technology and today are less capable because of that.
Room correction and the like should not be done on the sub, but upstream. Sub dsp delays are what necessitate timing correction upstream too. They are causing problems with the sub dsp and then you need to correct for those…
@@razisn I do equalize upstream (the files) for that very same reason. DSP equalization inside (or only for) the subwoofer can cause a important delay.
@I could not agree more, correct the room. But that doesn’t mean that corrections like level, slope, phase, bypass filtering, eq and lots more fine tuning controls shouldn’t be a part of the subwoofer’s offering for the sub-optimal listening conditions many face.
If we agree that all amps have a signature, then we must also agree that the amps used in active subs also have one. This kinda dwarfs the whole premise of "carrying through" the sound of your main amp,whether connected in either high level or low level,especially when the input impedance is so high (on "high level") that very little of the main amps sound characteristics are able to get through. It's not a formula that i buy into myself.
"kinda dwarves".
Well it means it could, but you would have to produce evidence of any specific combination, but, in fact, as Paul said, the more you put the signature of the amp into the equation, those closer you get and that does seem to be reasonable.
Have you tried it or are you a theoretical physician?
Tbh I don't think I could identify a sound signature of a sub, maybe safe to say is where you hear the subwoofer amp less.
That's a great point! This sound signature thing will only be relevant with passive subwoofers.
I've never had a problem where the subwoofer is identifiable. Adding a subwoofer simply makes it sound like the speakers have more bass.
i where in the same boat as you for years, until i got the ability to adjust for delay in mains speakers and parametric equalization, and then having two subwoofers in stereo.
just saying how much better it can sound in the future with experience.
Do not agree - Paul just declared that ALL amplifiers have a Sound signature, then so does the Subwoofer's amplifier! As well the Subwoofer itself (cone material, crossover components, cabinet design) clearly have a Sound signature (as do All / Any speakers) and therefore the Sound signature of the Subwoofer as a whole far exceeds (out weighs) any so called Sound signature mimicking one is achieving via the main amplifier. Plus I might add that despite going through the main amplifier not adding a significant amount of Delay, there is 'already' inherent Delay in ALL subwoofers that 1. Is not being addressed (and is clearly audible) and 2. Going through the main only adds more Delay (even if a marginal amount more). I will add that some folks aren't as much affected by Timing/Delay as some others. And even to the point that many people actually LIKE a small amount of Delay as introduced by any Subwoofer, which has a slight "Fattening" of the bass sound. I, as you may have gathered already, do not like that and insist that my Subwoofers are Time aligned and In-phase.
Could those high level inputs work for home theater?
Not sure how the amps sound signature comes through a subwoofer as my rels have their own amps in them??? Makes no sense
What's with the db Drive box in the lower left hand corner? I thought we were engineering woofers? Not just buying mediocre car audio and putting it in a house 🤔
Don't skimp on a sub/s, those cheapies have a nasty 'sloppy' sound no matter what the config.
The real is the phase or delay matching btw your loudspeakers and subs.
So you take a line level signal, amplify it, then convert that high level back into low level only to be amplified again and you say that it sounds better that way? That has to be the worst advice I’ve ever heard……
There's one less step as high input don't need an opamp and that's something that can really change the tonality. 👍
Try it first then comment..
Powered Sub's are perfectly capable of extracting the amp's signature from a high level input. Then its amp adds whatever it adds. Every driver in any sound system should all be receiving the same signal. 50 year professional's do not give bad advise. If you choose not to hear him, that's on you. Figure out why he's right. Heck, call REL they will tell you the same thing. This is not an opinion thing.
What is a sonic signature? Skewed frequency response? Distortion? Phase shift? Or some unquantifiable magic?
A high fidelity amplifier doesn’t change the signal because it will have a flat response and vanishingly low distortion so where is the ‘signature’? If all amps have a sonic signature that will also apply to the active subs inbuilt amplification so now we’re talking about even further deviations from the source material. So do we now need amplifier and sub ‘synergy’?
What nonsense. If a sub is audible it simply isn’t set up properly, nothing to do with high level or low level inputs or your amplifiers ‘sonic signature’ not getting through. The only signature is from the transducers and the room.
Some audiophiles want to hear the music not some distorted representation of it while believing in magic. Some of us have a real grasp of engineering. This channel could be a source of real info, but it just keeps feeding the cult of audiophelia nonsense from 40 years ago.
Of course I’ve seen some PS Audio gear with a permanent inbuilt +7db boost in the bass so yeah that’s a signature right there - but that isn’t fidelity.
Waffle.
Third. 😊
First one here!
Who's Brandon?
What makes being first so important?
Would you find equal value in being the first victim of a serial killer?
Stop Being Stupid!
Agreed, amplifiers have sonic characteristics, or signatures.
In the 𝘴𝘵𝘳𝘢𝘪𝘨𝘩𝘵 𝘸𝘪𝘳𝘦 𝘸𝘪𝘵𝘩 𝘨𝘢𝘪𝘯 landscape of hifi, ... where is the exception for placing amps in series? (feeding an amplifier with another amplifier?)
Of course, it's a convenience feature. In a current kludge, I'm operating active monitors fed by a throwaway cheap receiver in one system.
One of my first hifi subs had high level inputs (~35yrs ago), for connectivity convenience.
I would like to know the specific electronic advantage that is imparted on the second amplifier's sonics.
How can a quality subwoofer amplifier be superior in performance, when fed high level rather than line level?
There's just signal voltage, drive current ...
Temporal variations, plus distortion nonlinearities.
- What's the 𝘫𝘦 𝘯𝘦 𝘴𝘢𝘪𝘴 𝘲𝘶𝘰𝘪 imparted onto the second amplifier's output?