Room modes don't change depending on where you put the microphone and the listener position; they are inherent to the room geometry and the boundary conditions (and air properties), and are independent of sourcing and mic position. What changes is the driven response, and so you might see renonances appear and disappear as you move things around, but each mode has it eigenvalue (the frequency) and eigenvector (the pressure distribution across the room) stay the same, as long as the room stays the same.
Great video! There's actually a good trick I've employed in a few rooms that I don't hear very often. Speakers close to the wall with thick abortion can indeed help the SBIR null but Ive seen it exagerate other room modes. On the other hand in many residential sized rooms pulling out over 3 feet can be a bit obnoxious. Especially in home theaters. There's a third solution. If you bass trap most of the wall to wall and wall to ceiling corners and throw the subwoofer in the front corner you'll probably get fairly even response after EQing unless you have reallt poor dimensions or a tiny room. So in this SBIR trick you'll pull your speakers just a bit out from the wall. Say somewhere around 18" from the rear of the speaker. With most speakers this will usually put the SBIR null somewhere arpund the 100-120 htz range. It's important to measure here to pinpoint it. Then you just set the crossover to the sub a little higher than the null. The Negative here is the subwoofer might sound a little directional this high. It won't be very noticeable but if it bothers you just put a second sub in the other front corner and voila... diectionality gone. The most successful residential room I treated employed this tactic and it was small. About 10.5 ft x 13 ft. I had all corners trapped with 4" 2'x4' panels. I had a 6" panel on the ceiling's first reflection. 2" panels on the walls first reflection. 2 4" panels on early reflections. All of these panels being materials with OC703 like absorbtion . Then I put two 4'x4' panels on the rear wall with a foot of mineral wool, specifically Owen's Corning Fire and Sound batts. The room was a bit dry but after I utilized Sonarworks EQ I was shockingly really close to a mastering rooms frequency response. So I went completely overboard and built a desk where the desktop was made of OC703 and then I put a screenlike material over that to protect it. Amazingly, This brought the REW measured response to within 6 dB across the full range after Sonarworks EQ. Voila, mastering room frequency response in an average sized bedroom. People will harp how dry the room is. Even sub range was fairly dry. But for super critical listening I was a fan! Any little flaw was audible. After spending enough time in the room you adjust to the dryness and learn how much verb to apply. The awesome thing about that room is the bass was so tight it just smacked you right in the chest. Even snares could be felt well. The staging and separation was also excellent. I didn't realize that "Blood On The Dancefloor" would become one of my top 5 favorite mixes until I heard it on that super accurate staging.
Love the video. Any time Grimani is on the channel, it is like a masterclass from a guy who has been doing this for decades, and having him and Matthew Poes in dialog is fantastic. Matthew takes all this knowledge and translates it into real world realistic practical approaches for those of us that cannot spend six figures on our home theater! That said, they have both been pretty transparent about naming names in the past, companies and products worthy of praise. But this time although they mentioned that SOME in wall (baffle mounted) speakers have solved the imaging depth problem, a few times, they didn't actually mention which those are. I found that disappointing, since that would solve SBIR without the one key stumbling block (less depth to the acoustic image) that people trot out. So it seems likely that one of the best solutions could be achievable without a lot of sacrifice......if we were privy to what these two titans have learned with real speakers.
Extremely informative! You've convinced me that I need some absorbers behind the left and right speakers, and potentially move them closer to the wall to increase the frequency where SBIR happens
This is good stuff for me to learn. I feel like I've reached the top of the line for speakers for the time being. Now it's time to start putting some real time into room treatments. My room is treated, but content like this is great to move forward for do it yourselfers like me and others.
Hey Matthew Poes, I'm glad to see that the advice you requested from me regarding binaural audio was of use to you. It was cool to have those guys from Sonic Presence on during last year's HiFi Summit. Remember the one thing I asked for in our email in exchange for my help. 👊😎
Omg Joe I am so sorry. I got caught up in the moment and forgot. I will give you a shoutout next time. And for sure to everyone, Joe is the one who put me in touch with these guys. It’s a very cool product and I much appreciate the suggestion.
@@erod9088I can see why you might think what you think, but I'm pretty sure you do not know what the deal is between us. It's a deal we had from one man to another. It's just about principle and keeping one's word. That's important to me, even if it might seem petty to others. That's it. It's no big deal. Just a friendly nudge as a reminder. He apologized and that's it. No need to turn this into something it's not.
@@Audioholics to be clear, that was NOT me you're referring to regarding the SD Card, that was Techno Dad. That's between you guys, so leave me out of that. This is specifically to Matthew Poes. He wrote me numerous emails that are some of the longest emails I've ever received, like this reply, they were like essays 😂. He was asking me for input on how I do binaural recordings followed up with a phone call that lasted about an hour+. Gene, a better example would have been when I spent a few hours helping you get your Scarlett 2i2 setup with your previous mic to help you improve your audio for your videos. Like, I said to you and to Matt privately, I will repeat it again publicly, is that showing appreciation towards others is something that is important to me personally. (Side note, you did thank me numerous times so I have no issue with you on that.) Another value that's important to me is when someone agrees to something, I expect them to keep that agreement with me the way Matt agreed to the condition that if I helped him in any way, that he would acknowledge my help if he found it useful. He didn't, so I reminded him. Done! The man apologized and I accept the apology. The end.
Sub sections: ALWAYS in the corners are my mantra. Sooo much easier to integrate and to help cancel nulls. And ofc. 4 of them minimum. I also run my sides and rears (1m high good sizes) with proper amps and full-frequency. To me that sounds way better than cutting them off at 80 or similar. I am starting to think cutting off decent sized speakers at f.ex. 80hz is for puny receivers as they do not have enough power...
This is one reason why subwoofers will always improve a system, even if the speakers are full range. Pull the speakers out from the front wall, put the subwoofers against the wall, and cross over at a frequency whose quarter wavelength is shorter than the distance from the speakers to the wall. Problem solved.
Another Great Video Thanks. I sit at home thinking about stuff and have been wondering about reflections from my sofa. Its leather with a metal frame and has recliners on the end. I noticed the other day when I was leaning back on the sofa it lifted up created a gap underneath, my bass response seemed to improved. I think this was because I had allowed a gap under the sofa and the bass wasnt rebounding back towards the speakers. I recently decided to get rid of my coffee table for this reason. Im now thinking of getting a new sofa that's on legs to allow a flow underneath. Im I being silly and imagining things. Ive yet to get out the mic and try measuring it. Thanks.
B.t.w, as far as the 3 voices go, the most unnatural sound came from Anthony with reverberance at mid range frequencies. In 2'nd place was the binaural microphone sound with slight reverb at all frequencies & the most natural lifelike sound by far, came from Gene. Sorry to go off topic.
Really enjoyed the video Gene, Matthew and Anthony. A question I would ask would be about the increase effectiveness by using standoffs to mount acoustic panels and how much surface pressure zones come into the that effect.
Gene's room measurement, with 1/24 smoothing, would you EQ that? Or would you just use more smoothing to cover it up if you couldn't use absorbers and room treatment?
For SBIR big speakers is a issue. That is what I am saying: "That optimal placement of tweeter and midrange driver is not always the exact optimal position for the bass." In other words if we could sepperate/remove the bass parts from Gene big speakers and put those in a much better position then problem solved. So THAT is a point why a bookshelves and subs is "better" when they can be placed optimal in the room for each type of duty they have. (If well integrated). Floor standers can give you issues that bookshelves and subwoofers can fix.
Yea to a point. Nothing sounds better than a fully integrated large scale tower. The dynamics are just unbelievable. Ideally putting the mid/tweet module in its current location and placing the subs in the walls would be better but impractical due to their sheer size.
@@Audioholics Respectfully disagree. I would say the opposite after seeing this video, that a fully integrated large scale "bookshelves + bass" in acustical optimized placement is as you know the thing that sounds the best. When the two people in the video tell you that you should disassemble the tower configuration that you have. And use the middle section "as bookshelves" and put the bass sections in a more sonically optimal position. To fix your issue and getting better sound. So logical the full large scale configuration you have now is not the best those speakers can sound in that room. They can not because of physics sound "better" at the moment. So probably you are fouling your self to think that. Saying that respectfully! You have decided to prioritize that they look visual better and the big upside is that it takes less floor space. If there is nowhere to put the bass modules I get that compromise. Thanks for a great video!💖
@@AmazonasBiotop I would respectfully disagree with you good sir! You are 100% correct but What Gene 🧬 is going for is sheer scale. Our brains cannot be fooled when speakers are bigger and run full range. I can’t quite explain it but it sounds “BIG” vs “small” in both movies and music. So keep the big badass towers Gene.
@@AmazonasBiotop you.can disagree but it doesn't mean you're right. I've set up 100s of small speaker multi sub systems and thry never come close to the full scale sound you get from a large tower like this. This is why I'm taking the extra effort to put more passive treatments like discussed in this video along with equalization.
Instead of absorbers behind the main speakers, why not a hard reflective board that is at an angle (say 20 degrees) to the wall. The pressure waves causing the SBIR would have to follow a different path to the listener and would no longer cancel. Effectively, it shifts the phase of the bass hitting the board so no cancelation.
Great video- very well done. OMG the sibilance and distortion on Mathew’s end is HORRIBLE. I had to take out one of my earbuds to get rid of some of that weird phase distortion. Please get a decent mic of some sort. It doesn’t even cost much to get a better mic nowadays.
Yeah if you have line source speakers like some in wall Wisdoms. Or the new Perlisten S7t floorstanders with very clever beamforming that minimise the floor and ceiling reflections.
In-wall/soffit mounted monitors only address front wall SBIR, and do nothing to address every other wall and reflective surface. In fact, because they are often mounted high on the walls in the case Augspurger’s, ATC, PSI, Adam and many others, they often substantially increase often untreated, very near ceiling related SBIR. Other issues with in-wall is often poor imaging due to a lack of actual or virtual open baffle and related support. When you couple that with strong structural/wall coupling that quite often is the case, and strong in-wall resonance and reflections back to the monitor due to constrained in-wall areas, these are the reasons why even in many (albeit not all) of the top recording studios, the in-soffit mains are the “limited use party” speakers and NOT the critical listening, mixing or mastering speakers.
Anthony Grimani a man to my heart. Laphroaig Scotch (Ps. it's law all Whisky made here in Scotland is labeled as Scotch) Whisky 🏴🥃 and Dark Chocolate 🍫 a great combination 👌🏾
43:32 DIY diaphram solution. If I get it right. I will take 4" deep wool and on it I will glue on 8" width but thin layer of ply wood to create some kind of membrane which will work better for some low frequencies then wool alone.
Now big question is: if Dirac can narrow this dip to few Hz - does it matter if exists? I mean from psychoacoustic side we would most likely not hear that dip. Nothing in the movie will play specifically that frequency flat out. So spending too much time or money on room treatment just to make a line flat is not worth IMO. I’m not against room treatment but against over doing it.
Gene 🧬 here’s an idea that I’m 100% serious about. It’s about using brute force-hear me out. Get a third RBH 400 LB full range tower and use that behind your screen as a center channel and run all 3 front channels full range. I don’t know what but full range large speakers just sound different and foe dialogue, they take things to a mew level
@@Audioholics LOL 😂 I recently bought LCR from Atlantic Technology (8600) series. I then hooked up each one over high level to a REL T9i (so 3 rel subs). I now run all channels full range and I swear to God to his it’s magical, because I’m a big believer in the front stage being as similar as possible. Hence my advice. I power them with a Parasound a31 and Yammy 5200. Come have a listen if you’re ever in Texas!
@@Audioholics Your two large towers with a puny li'l center in the middle somehow reminds me a dude who's hitting the gym pumped on steroids and produced huge arms, but shrunk in the middle...you know what i mean. It's not a good look. A real strong man will also have a real strong huge floorstander in the middle. lol
Thank you so much for this so informative video!! I have a question as are room modes just about the reflection and interference? As I understand they increase or weaken the direct energy itself also while there are no reflections yet or almost won’t be due to the room is dry. Because when the direct energy is spreading before the reverberation it is like vibrations of speaker on the frequencies of power having while it’s own frequency causing resonance (the forced mode). Thank’s for the someone’s answer!
I have a idea I want to try. What if I built 12 inch thick front wall Rockwool bass traps and in the middle I put MLV ? I think against the Rockwool sandwiched that it might act dysgraphamatic across lower frequencies.
It was only on the third attempt I got the subwoofer EQ better figured out. SVS "only" gives you 3 bands of free EQ to tinker with, so perseverence paid off but I was going pretty nutty and disapointed at the meager results of the two first attempts. I'm dumb enough to have 2 subwoofers still in stereo mode so they can play individual material, this is not recommended. I have a mic + REW 1st attempt I kept getting frustrated by only having 3 bands and so many peaks and valleys to correct... results was poor. 2nd attempt I thought I'd deal with it "scientifically", I opted to correct one sub as best I could before moving on to the other. When I was done he L and R sub response curve was really good with only 1 needle thin drop + minor valley. Then I drove L and R together = complete disaster, the subs where interacting really poorly! Very sad day. 3rd attempt, I nulled all settings, deleted 50-75 of sub sweeps graphs. Time to think outside the box: instead of letting surround processor stay at "typical" 80Hz, I let main speakers play down further and sent full frequency signal to subs. By doing that I could set a difference during cross over point and that solved some issues. Then the EQ strategy is to only work with L and R playing at same time, that way you can see if any changes has unintended consequences elsewhere. When you apply EQ's you are also imposing a phase shift that effects adjacent frequencies - for better or worse! So, I worked through applying EQ but it wasn't going great, I had an insane peak at 37Hz. I could get a 4th EQ band by using SVS "room boom correction" however that dragged the frequency response of 17-24 Hz down. It was a necessary sacrifice. 37Hz still had a massive peak. Then I tested correction on each sub but still sweeping in stereo, this made me realise which sub made the largest effect for same correction magnitude (and didn't screw up something else). This tactic worked so much better, takes hours though. I also looked back at the largest offending frequencies, used the tone generator and figured out where the largest null spots where located, by moving seats a foot forward I avoided some large issues.
Anechoic is an ideal space for testing loudspeakers but NOT listening to loudspeakers. You need some reflections or the sound will be unpleasant and unrealistic.
I am curious what you found as a solution. My KEF R11 measure well close to the wall but no imaging. 4-5 feet off the wall big dips in lower bass and rise in middle bass. Great imaging though!
Yep, very common. You can add subs on front wall and bass manage your Kefs. You can boost the nulls up to 3-4db if it helps the multiple seat locations.
Yep. I have four monolith subs that I use with a Denon 3600 (Amps Disabled) and can smooth it out. Problem is with 2-channel. The 3600 DAC is not nearly as good as the DAC on the Panasonic UB9000 that I use for 2-channel. If the analog signal passes through the 3600 imaging suffers. @@Audioholics
Can you stack SBIR peaks and dips on top of each other? Like distance to the front wall would be half of the distance that is between the speaker and the floor? I figured stacking LBIR and SBIR dips might be a bit out of whack since your head moves all the time.
I think you are referring to something we covered. They can compound and make a problem worse. The worst problem is when you have them fall within 1 octave creating a huge wide dip.
@@PoesAcoustics I meant to make 1/4 wavelength to the front wall equal to 1/2 wavelength to the floor. Theoretically the peak and dip should cancel each other out.
It will work if the diffuser frequency range is in the range of the SBIR. And we all know diffusers, like absorbers tend to be difficult to tune for low frequencies where SBIRs are a major problem.
My system: 10" woofer 3ft from either wall, sub: 6" forward from the common plane of the woofers. Room: 20ft x 12ft x 8ft sound only gells near to 15+ ft from speakers. I do enjoy, but could it get better?
Get a UMIK-1 and MiniDSP 2x4 HD and you’ll be able to see how your sub is doing. Most people recommend this for a reason. It really opened my eyes and made me go from 1x PB-1000 Pro to 4.
The acoustic dream team, love it guys! So if in wall speakers eliminate the SBIR issue, why all the talk that they are inferior to cabinet speakers? Or is that an old myth at this point?
@@Audioholics yes except that Anthony said a few companies have solved that.....and then didn't name names, which is odd, because he is usually happy to praise people who are making quality stuff.
I just bought a Marantz RS8015 I have no Speaker interference problems but that is probably because i dont have any speakers.I think it will take me a year to buy some decent speakers untill that time i will have no speaker problems i guess.
Now you know... When a reviewer says something about a new product "improving the bass" its all Bullshit. The only way to "improve bass" is to improve or optimize the position of sources and the acoustic performance of the room. "The kick drum hits harder" my ass.
I have a very small room 10 x 10 with very large speakers for it's size and I have a huge 80-90 hz dip, it's very annoying because I can move my head around and the dip goes away. I can't really move my speakers or my furniture because my room is so small, I have my couch as far is I can off the wall without running into the TV.
Have you tried with the couch closer to the wall. I know people say not to do that. But honestly, if you can easily push the couch back, may be worth a try. I've had decent experience with couch very close to wall.
@@Edward135i a few other things to try would be moving the subwoofer or adding more subwoofers. But I understand that may not be do-able. Also simply trying a different crossover frequency sometimes gets rid of, or lessens these kind of problems. Just trying to think of the simple solutions to try.
That could be most certainly a mode given the dimensions of the room and the fact that lenght is the same as width. Both axial modes would be coincidental, thus an added undisirable effect at that given frequency. The simplest way to go is corner absorbers, min 10" thick and repositioning the subwoofer in a non simetrical way corresponding to the sidewalls. Say as closer you can from the front wall, but off set from the center. Same goes for left and right. Set them in a way that the measured distances from the walls are a bit different by, say 4". Left will be 3" away of the front wall and 5" from left wall, and the right speaker will be 2" from the front and 6" from the right wall.
You need to have your absorption panels away from the wall makes them more effective how far not sure maybe a couple of inches try it out see what your measurements are Plus you can have thin absorption panels like half an inch of wool fleece and leave gaps between the panels would work the best better than having one 4-inch absorption panels on its own what the measurement factor I'm not sure tested out. I would have thought it would give you a equivalent to 8-inch panel or more Try mixing materials up different fibres works better, like with half an inch of fleas half an inch of cellulose foam some natural cotton underlay and with the gaps and to the wall. the different material work better with different frequencies fleece is best for lower frequencies below 100 Hz Papers good as well that's why they use in offices paper panels or tiles. You could use some office paper panels used as dividers your speakers like a false wall extending the baffle. What I would do Glen some natural wool fleece half an inch folding over and then behind that put the half an inch paper panel would work the best You talk about fibreglass rockwool is a lot better than fiberglass that's what's used in Studios. The place them in the Wall in studios to achieve infinite baffle. You could make your own active absorbers if you place a speaker in a tunnel long funnel just a little slit against the side walls pointing towards your main speakers with DPS you could tune the Frequency to cancel out the Frequency from your main speakers just have to get the phase correct out of phase
Rockwool isn't much better than fiberglass/mineral wool. GIK acoustics and lot's of other reputable companies use ecose mineral wool for their absorbers.
@@C--A I meant sheep wool not mineral wool don't know about the other stuff you mentioned, the sheep's wool is one of the best especially down to 20 Hz or below
@@johnsweda2999 I’ve never found there to be any meaningful differences beyond differences in density and rigidity. Absent a membrane of some kind, a thin layer of any insulation isn’t very useful at these low frequencies. There has been more recent research on the gap or spacing of panels to test the change in absorption. It was found that argument was a mistake. Not totally, you get benefit to a point, but the assumptions in the original theory turned out to be largely wrong. You can add only up to about 2” of air gap and only if the panel is itself at least 4” thick. If the panel is 2” thick, only 1” gap. Beyond that, there is nothing gained. And the gain isn’t as great as expected. It was originally due to a problem in how we measure absorption in a lab. Once that is corrected for the difference is marginal. On 2” to 4” panels it’s worth doing the 1”-2” gap but don’t go crazy.
@@wa2368 it was based on a study that Ron Sauro did at NWAA labs where he was testing various methods of assessing absorption. He mentioned finding that the airgap was overblown and only effective at a very small amount. He actually told me not to gap panels more than an inch and that the gap didn’t give it the equivalent absorption of a 3” panel per say. I dug a bit deeper with him and ultimately concluded that with thicker and higher density panels it is likely that a 2” gap would still offer some benefit. Given that it’s free. The main point is, don’t think that adding a 2” gap to a 2” panel is going to give you the same absorption performance as a 4” panel would have. It’s not that good apparently. I can reach out to Ron to see about getting some of the data. I can’t seem to find it publicly now.
I really enjoy these videos, but at the same time i'm often disappointed about your audio quality in these videos. Matthew's binaural mic setup is fun and all, but when they're so close to his earbuds, it's asking for problems. Gene has the right idea, boommic and headphones. And strangely, Anthony's setup didn't cause any problems. I guess he had his monitors volume low enough and maybe a gate on his mic. Do you guys test for problems before going live?
No this is just the nature of livestreaming. None of us have the time to rehearse prior and many times Anthony and Matt are on location at a client's home and limited to equipment they can use. We emphasize quality of content over production and no fluff. Hope that is compelling enough for you to continue to watch.
@@Audioholics it won't keep me from watching or reading your content. I understand your arguments, however was hoping for a bit more production value. I'm almost positive it would benefit the channel in the long run.
I don't get it why Gene needs such huge speaker in that thiny room , Solution will be moving speaker from the wall , LOL, it will be huge speaker in front of face , Gene you need bigger house or smaller speaker, these guy they don't know what they talking about, very irony solution from experts, 🤣🤣🤣🤣
The comments in the video about why speakers can sound better when moved away from the walls actually has a lot of engineering and science behind it. One of the key areas is directivity. (secure.aes.org/members/insidetrack/201911/) This is a set of articles going back for over 40 years on this area of acoustical concern. Another mention in the video why some in wall sound great and others do not is also highly influenced by phase alignments (in the time domain ) and the radiation patterns of the drivers over their operating frequencies. Good luck resolving your suck out issues...... there are active methods also that can help reduce the issues (noise canceling methods).
Got any references to data or measurements or studies that show the technical characteristics of in wall speakers that create sound stage depth? Grimani says there are some but doesn’t name any, which is unusual for him since he is usually okay with naming names when a company does something well. Maybe he meant it is theoretically possible or he has heard prototypes but nothing is actually on the market?
Room modes don't change depending on where you put the microphone and the listener position; they are inherent to the room geometry and the boundary conditions (and air properties), and are independent of sourcing and mic position. What changes is the driven response, and so you might see renonances appear and disappear as you move things around, but each mode has it eigenvalue (the frequency) and eigenvector (the pressure distribution across the room) stay the same, as long as the room stays the same.
Mathew , Anthony and Gene. What an awesome combo
Great video! There's actually a good trick I've employed in a few rooms that I don't hear very often. Speakers close to the wall with thick abortion can indeed help the SBIR null but Ive seen it exagerate other room modes. On the other hand in many residential sized rooms pulling out over 3 feet can be a bit obnoxious. Especially in home theaters. There's a third solution. If you bass trap most of the wall to wall and wall to ceiling corners and throw the subwoofer in the front corner you'll probably get fairly even response after EQing unless you have reallt poor dimensions or a tiny room. So in this SBIR trick you'll pull your speakers just a bit out from the wall. Say somewhere around 18" from the rear of the speaker. With most speakers this will usually put the SBIR null somewhere arpund the 100-120 htz range. It's important to measure here to pinpoint it. Then you just set the crossover to the sub a little higher than the null. The Negative here is the subwoofer might sound a little directional this high. It won't be very noticeable but if it bothers you just put a second sub in the other front corner and voila... diectionality gone. The most successful residential room I treated employed this tactic and it was small. About 10.5 ft x 13 ft. I had all corners trapped with 4" 2'x4' panels. I had a 6" panel on the ceiling's first reflection. 2" panels on the walls first reflection. 2 4" panels on early reflections. All of these panels being materials with OC703 like absorbtion . Then I put two 4'x4' panels on the rear wall with a foot of mineral wool, specifically Owen's Corning Fire and Sound batts. The room was a bit dry but after I utilized Sonarworks EQ I was shockingly really close to a mastering rooms frequency response. So I went completely overboard and built a desk where the desktop was made of OC703 and then I put a screenlike material over that to protect it. Amazingly, This brought the REW measured response to within 6 dB across the full range after Sonarworks EQ. Voila, mastering room frequency response in an average sized bedroom. People will harp how dry the room is. Even sub range was fairly dry. But for super critical listening I was a fan! Any little flaw was audible. After spending enough time in the room you adjust to the dryness and learn how much verb to apply. The awesome thing about that room is the bass was so tight it just smacked you right in the chest. Even snares could be felt well. The staging and separation was also excellent. I didn't realize that "Blood On The Dancefloor" would become one of my top 5 favorite mixes until I heard it on that super accurate staging.
Love the video. Any time Grimani is on the channel, it is like a masterclass from a guy who has been doing this for decades, and having him and Matthew Poes in dialog is fantastic. Matthew takes all this knowledge and translates it into real world realistic practical approaches for those of us that cannot spend six figures on our home theater!
That said, they have both been pretty transparent about naming names in the past, companies and products worthy of praise.
But this time although they mentioned that SOME in wall (baffle mounted) speakers have solved the imaging depth problem, a few times, they didn't actually mention which those are.
I found that disappointing, since that would solve SBIR without the one key stumbling block (less depth to the acoustic image) that people trot out. So it seems likely that one of the best solutions could be achievable without a lot of sacrifice......if we were privy to what these two titans have learned with real speakers.
Extremely informative! You've convinced me that I need some absorbers behind the left and right speakers, and potentially move them closer to the wall to increase the frequency where SBIR happens
This is good stuff for me to learn. I feel like I've reached the top of the line for speakers for the time being. Now it's time to start putting some real time into room treatments. My room is treated, but content like this is great to move forward for do it yourselfers like me and others.
Amazing video Gene, Matthew Poes and Anthony Grimani !!!
This really should be added to that Audioholics youtube playlist: Room Acoustics
👍
Good idea, will add.
@@Audioholics thanks. Glad to help.
I intentionally responsibly avoid any meetings at work following the morning of an Audioholic live stream, one must have priorities.
This is way more important
Thank you guys, great information!
I see too many forum members give advice to others with no idea of what the real problem is.
Hey Matthew Poes, I'm glad to see that the advice you requested from me regarding binaural audio was of use to you. It was cool to have those guys from Sonic Presence on during last year's HiFi Summit. Remember the one thing I asked for in our email in exchange for my help. 👊😎
Omg Joe I am so sorry. I got caught up in the moment and forgot. I will give you a shoutout next time.
And for sure to everyone, Joe is the one who put me in touch with these guys. It’s a very cool product and I much appreciate the suggestion.
The incessant need for RUclipsrs to get credit is hilarious. It was just an introduction. 😂
@@erod9088I can see why you might think what you think, but I'm pretty sure you do not know what the deal is between us. It's a deal we had from one man to another. It's just about principle and keeping one's word. That's important to me, even if it might seem petty to others. That's it. It's no big deal. Just a friendly nudge as a reminder. He apologized and that's it. No need to turn this into something it's not.
@@erod9088 Yea I had a fellow RUclipsr lambast me because I forgot to publically thank him for lending me a $40 SD card a couple of years ago.
@@Audioholics to be clear, that was NOT me you're referring to regarding the SD Card, that was Techno Dad. That's between you guys, so leave me out of that.
This is specifically to Matthew Poes. He wrote me numerous emails that are some of the longest emails I've ever received, like this reply, they were like essays 😂. He was asking me for input on how I do binaural recordings followed up with a phone call that lasted about an hour+.
Gene, a better example would have been when I spent a few hours helping you get your Scarlett 2i2 setup with your previous mic to help you improve your audio for your videos. Like, I said to you and to Matt privately, I will repeat it again publicly, is that showing appreciation towards others is something that is important to me personally. (Side note, you did thank me numerous times so I have no issue with you on that.)
Another value that's important to me is when someone agrees to something, I expect them to keep that agreement with me the way Matt agreed to the condition that if I helped him in any way, that he would acknowledge my help if he found it useful. He didn't, so I reminded him. Done! The man apologized and I accept the apology. The end.
Sub sections: ALWAYS in the corners are my mantra. Sooo much easier to integrate and to help cancel nulls. And ofc. 4 of them minimum. I also run my sides and rears (1m high good sizes) with proper amps and full-frequency. To me that sounds way better than cutting them off at 80 or similar. I am starting to think cutting off decent sized speakers at f.ex. 80hz is for puny receivers as they do not have enough power...
Great video. Keep up the good work.
Great stuff. Going to soffit mount my LCR in the wall with a custom baffle.
This is one reason why subwoofers will always improve a system, even if the speakers are full range. Pull the speakers out from the front wall, put the subwoofers against the wall, and cross over at a frequency whose quarter wavelength is shorter than the distance from the speakers to the wall. Problem solved.
How do you know, or could you tell if it’s a front/back, side or ceiling reflection, or if it’s a dip or even room mode?
Another Great Video Thanks. I sit at home thinking about stuff and have been wondering about reflections from my sofa. Its leather with a metal frame and has recliners on the end. I noticed the other day when I was leaning back on the sofa it lifted up created a gap underneath, my bass response seemed to improved. I think this was because I had allowed a gap under the sofa and the bass wasnt rebounding back towards the speakers. I recently decided to get rid of my coffee table for this reason. Im now thinking of getting a new sofa that's on legs to allow a flow underneath. Im I being silly and imagining things. Ive yet to get out the mic and try measuring it. Thanks.
B.t.w, as far as the 3 voices go, the most unnatural sound came from Anthony with reverberance at mid range frequencies. In 2'nd place was the binaural microphone sound with slight reverb at all frequencies & the most natural lifelike sound by far, came from Gene. Sorry to go off topic.
Really enjoyed the video Gene, Matthew and Anthony. A question I would ask would be about the increase effectiveness by using standoffs to mount acoustic panels and how much surface pressure zones come into the that effect.
Gene's room measurement, with 1/24 smoothing, would you EQ that? Or would you just use more smoothing to cover it up if you couldn't use absorbers and room treatment?
Great and informative presentation! Thank you.
It was really good help to me :) Thank you so much guys!!
For SBIR big speakers is a issue.
That is what I am saying:
"That optimal placement of tweeter and midrange driver is not always the exact optimal position for the bass."
In other words if we could sepperate/remove the bass parts from Gene big speakers and put those in a much better position then problem solved.
So THAT is a point why a bookshelves and subs is "better" when they can be placed optimal in the room for each type of duty they have. (If well integrated).
Floor standers can give you issues that bookshelves and subwoofers can fix.
Yea to a point. Nothing sounds better than a fully integrated large scale tower. The dynamics are just unbelievable. Ideally putting the mid/tweet module in its current location and placing the subs in the walls would be better but impractical due to their sheer size.
@@Audioholics Respectfully disagree.
I would say the opposite after seeing this video, that a fully integrated large scale "bookshelves + bass" in acustical optimized placement is as you know the thing that sounds the best.
When the two people in the video tell you that you should disassemble the tower configuration that you have. And use the middle section "as bookshelves" and put the bass sections in a more sonically optimal position. To fix your issue and getting better sound.
So logical the full large scale configuration you have now is not the best those speakers can sound in that room.
They can not because of physics sound "better" at the moment. So probably you are fouling your self to think that. Saying that respectfully!
You have decided to prioritize that they look visual better and the big upside is that it takes less floor space. If there is nowhere to put the bass modules I get that compromise.
Thanks for a great video!💖
@@AmazonasBiotop we also said this during the video. More than once in fact. Gene doesn’t want to take them apart because it won’t look as imposing.
@@AmazonasBiotop I would respectfully disagree with you good sir! You are 100% correct but What Gene 🧬 is going for is sheer scale. Our brains cannot be fooled when speakers are bigger and run full range. I can’t quite explain it but it sounds “BIG” vs “small” in both movies and music. So keep the big badass towers Gene.
@@AmazonasBiotop you.can disagree but it doesn't mean you're right. I've set up 100s of small speaker multi sub systems and thry never come close to the full scale sound you get from a large tower like this. This is why I'm taking the extra effort to put more passive treatments like discussed in this video along with equalization.
Instead of absorbers behind the main speakers, why not a hard reflective board that is at an angle (say 20 degrees) to the wall. The pressure waves causing the SBIR would have to follow a different path to the listener and would no longer cancel. Effectively, it shifts the phase of the bass hitting the board so no cancelation.
Wondering if 3d diffusion right behind the rear speakers could also help resolve SBIR? Like in Blackbird Studios.
Great video- very well done. OMG the sibilance and distortion on Mathew’s end is HORRIBLE. I had to take out one of my earbuds to get rid of some of that weird phase distortion. Please get a decent mic of some sort. It doesn’t even cost much to get a better mic nowadays.
Use inwalls where possible. Modern inwalls are great in small/medium rooms. Lol. Watched further. You said that.😎
Wouldn't ceiling (and floor) reflexions also be significantliy reduced by the line array speakers?
Yeah if you have line source speakers like some in wall Wisdoms. Or the new Perlisten S7t floorstanders with very clever beamforming that minimise the floor and ceiling reflections.
@@C--A the RBH speskers have a very similar narrow vertical dispersion of the Perlisten.
In-wall/soffit mounted monitors only address front wall SBIR, and do nothing to address every other wall and reflective surface. In fact, because they are often mounted high on the walls in the case Augspurger’s, ATC, PSI, Adam and many others, they often substantially increase often untreated, very near ceiling related SBIR. Other issues with in-wall is often poor imaging due to a lack of actual or virtual open baffle and related support.
When you couple that with strong structural/wall coupling that quite often is the case, and strong in-wall resonance and reflections back to the monitor due to constrained in-wall areas, these are the reasons why even in many (albeit not all) of the top recording studios, the in-soffit mains are the “limited use party” speakers and NOT the critical listening, mixing or mastering speakers.
Can you please tell more about in wall speaker poor imaging or give links to the information?
Anthony Grimani a man to my heart.
Laphroaig Scotch (Ps. it's law all Whisky made here in Scotland is labeled as Scotch) Whisky 🏴🥃 and Dark Chocolate 🍫 a great combination 👌🏾
Does anyone know what the blue software that calculates SBIR is called?
Just the video I needed.
Glad you found it helpful!
Great info, But Gene, where did you get that shirt? I want one!
Could you use cheap passive radars in thin enclosures to use as bass traps
43:32 DIY diaphram solution. If I get it right. I will take 4" deep wool and on it I will glue on 8" width but thin layer of ply wood to create some kind of membrane which will work better for some low frequencies then wool alone.
Ceiling SBIR @ 30hz ? Height of Gene room ? distance of listening ?
My SVS subs point at the floor. I think that's a great way to do it. It also shakes the couch without butt kickers.
I guess matthews binaural mics and earbuds were feeding back.
Now big question is: if Dirac can narrow this dip to few Hz - does it matter if exists? I mean from psychoacoustic side we would most likely not hear that dip. Nothing in the movie will play specifically that frequency flat out. So spending too much time or money on room treatment just to make a line flat is not worth IMO. I’m not against room treatment but against over doing it.
Gene 🧬 here’s an idea that I’m 100% serious about. It’s about using brute force-hear me out. Get a third RBH 400 LB full range tower and use that behind your screen as a center channel and run all 3 front channels full range. I don’t know what but full range large speakers just sound different and foe dialogue, they take things to a mew level
Lol wish that were practical. I did get great integration between the center and subs though. The mid/tweet section is identical.
@@Audioholics LOL 😂 I recently bought LCR from Atlantic Technology (8600) series. I then hooked up each one over high level to a REL T9i (so 3 rel subs). I now run all channels full range and I swear to God to his it’s magical, because I’m a big believer in the front stage being as similar as possible. Hence my advice. I power them with a Parasound a31 and Yammy 5200. Come have a listen if you’re ever in Texas!
@@Audioholics Your two large towers with a puny li'l center in the middle somehow reminds me a dude who's hitting the gym pumped on steroids and produced huge arms, but shrunk in the middle...you know what i mean. It's not a good look. A real strong man will also have a real strong huge floorstander in the middle. lol
Thank you so much for this so informative video!!
I have a question as are room modes just about the reflection and interference? As I understand they increase or weaken the direct energy itself also while there are no reflections yet or almost won’t be due to the room is dry. Because when the direct energy is spreading before the reverberation it is like vibrations of speaker on the frequencies of power having while it’s own frequency causing resonance (the forced mode).
Thank’s for the someone’s answer!
I have a idea I want to try. What if I built 12 inch thick front wall Rockwool bass traps and in the middle I put MLV ? I think against the Rockwool sandwiched that it might act dysgraphamatic across lower frequencies.
Old Sony Trinitron. Fits in perfectly with the rug and the clock.
Any thoughts on open baffle speakers?
What would the measurement graph at 31 minutes look with PSY smoothing? This would more accurately resemble what it ‘sounds like’.
Too late now, i would have had Anthony provide an acoustic analysis of the room and have it built to his design. Plan it, build it, enjoy it.
He did provide feedback during the construction of the room and room treatments.
@@Audioholics Hope it works out for you.
It was only on the third attempt I got the subwoofer EQ better figured out. SVS "only" gives you 3 bands of free EQ to tinker with, so perseverence paid off but I was going pretty nutty and disapointed at the meager results of the two first attempts. I'm dumb enough to have 2 subwoofers still in stereo mode so they can play individual material, this is not recommended. I have a mic + REW
1st attempt I kept getting frustrated by only having 3 bands and so many peaks and valleys to correct... results was poor.
2nd attempt I thought I'd deal with it "scientifically", I opted to correct one sub as best I could before moving on to the other. When I was done he L and R sub response curve was really good with only 1 needle thin drop + minor valley. Then I drove L and R together = complete disaster, the subs where interacting really poorly! Very sad day.
3rd attempt, I nulled all settings, deleted 50-75 of sub sweeps graphs. Time to think outside the box: instead of letting surround processor stay at "typical" 80Hz, I let main speakers play down further and sent full frequency signal to subs. By doing that I could set a difference during cross over point and that solved some issues. Then the EQ strategy is to only work with L and R playing at same time, that way you can see if any changes has unintended consequences elsewhere. When you apply EQ's you are also imposing a phase shift that effects adjacent frequencies - for better or worse! So, I worked through applying EQ but it wasn't going great, I had an insane peak at 37Hz. I could get a 4th EQ band by using SVS "room boom correction" however that dragged the frequency response of 17-24 Hz down. It was a necessary sacrifice. 37Hz still had a massive peak. Then I tested correction on each sub but still sweeping in stereo, this made me realise which sub made the largest effect for same correction magnitude (and didn't screw up something else). This tactic worked so much better, takes hours though. I also looked back at the largest offending frequencies, used the tone generator and figured out where the largest null spots where located, by moving seats a foot forward I avoided some large issues.
What are the 2 USB mic's recommend for REW?
Buy saddle then the horse or buy the horse then a saddle for horse, which one is right
Why not move the xover up a little on the subs?
Ever try the sumiko speaker placement?
1:01:07 -- sound stage depth mystery -- negative feedback in the amplification.
Why not a Anechoic Control room/studio. Theoretically, is not that the optimal space?
Anechoic is an ideal space for testing loudspeakers but NOT listening to loudspeakers. You need some reflections or the sound will be unpleasant and unrealistic.
I am curious what you found as a solution. My KEF R11 measure well close to the wall but no imaging. 4-5 feet off the wall big dips in lower bass and rise in middle bass. Great imaging though!
Yep, very common. You can add subs on front wall and bass manage your Kefs. You can boost the nulls up to 3-4db if it helps the multiple seat locations.
Yep. I have four monolith subs that I use with a Denon 3600 (Amps Disabled) and can smooth it out. Problem is with 2-channel. The 3600 DAC is not nearly as good as the DAC on the Panasonic UB9000 that I use for 2-channel. If the analog signal passes through the 3600 imaging suffers. @@Audioholics
Matthew come visit South Africa 😊
What does the 'r' stand for in that acronym?
Response
Can you stack SBIR peaks and dips on top of each other?
Like distance to the front wall would be half of the distance that is between the speaker and the floor?
I figured stacking LBIR and SBIR dips might be a bit out of whack since your head moves all the time.
I think you are referring to something we covered. They can compound and make a problem worse. The worst problem is when you have them fall within 1 octave creating a huge wide dip.
@@PoesAcoustics I meant to make 1/4 wavelength to the front wall equal to 1/2 wavelength to the floor.
Theoretically the peak and dip should cancel each other out.
How about Anthony Matter ?
Is there a reason why acoustic diffusers weren't mentioned as a way to mitigate SBIR?
I'm also curious about diffusion vs absorption in SBIR treatment. Would like to see that discussed.
It will work if the diffuser frequency range is in the range of the SBIR. And we all know diffusers, like absorbers tend to be difficult to tune for low frequencies where SBIRs are a major problem.
My system: 10" woofer 3ft from either wall, sub: 6" forward from the common plane of the woofers. Room: 20ft x 12ft x 8ft sound only gells near to 15+ ft from speakers. I do enjoy, but could it get better?
Get a UMIK-1 and MiniDSP 2x4 HD and you’ll be able to see how your sub is doing. Most people recommend this for a reason. It really opened my eyes and made me go from 1x PB-1000 Pro to 4.
Wouldnt a DSP help out far more then just moving speakers around in hopes of finding a sweet spot
Positional EQ first, DSP after.
The acoustic dream team, love it guys! So if in wall speakers eliminate the SBIR issue, why all the talk that they are inferior to cabinet speakers? Or is that an old myth at this point?
There are always tradeoffs. An inwall speaker still typically doesn't image as well as a box speaker and there is less depth in Soundstage.
@@Audioholics yes except that Anthony said a few companies have solved that.....and then didn't name names, which is odd, because he is usually happy to praise people who are making quality stuff.
Whole setup should turn angeled in the room so the spk gap from walls are different lenghts, then standing-waves not occure same ferg
Maybe, but then you have a tiny room with awkward seating and impossible screen mounting.
Tip: The Echo is because Mats Mics are directly to his AirPods ;-)
Mic bleed
I just bought a Marantz RS8015 I have no Speaker interference problems but that is probably because i dont have any speakers.I think it will take me a year to buy some decent speakers untill that time i will have no speaker problems i guess.
Get some cheap Sony SS-CS5 to get started. Great reviews and can be upgraded with a kit from GR research
Now you know... When a reviewer says something about a new product "improving the bass" its all Bullshit. The only way to "improve bass" is to improve or optimize the position of sources and the acoustic performance of the room. "The kick drum hits harder" my ass.
I have a very small room 10 x 10 with very large speakers for it's size and I have a huge 80-90 hz dip, it's very annoying because I can move my head around and the dip goes away. I can't really move my speakers or my furniture because my room is so small, I have my couch as far is I can off the wall without running into the TV.
I was listening to this video because I'm in the same situation. 10x10 room and big dip at ~100 Hz.
Have you tried with the couch closer to the wall. I know people say not to do that. But honestly, if you can easily push the couch back, may be worth a try. I've had decent experience with couch very close to wall.
@@tonyb3350 no I haven't, I'll have to move my rear channels to do that, I'll give it a try.
@@Edward135i a few other things to try would be moving the subwoofer or adding more subwoofers. But I understand that may not be do-able. Also simply trying a different crossover frequency sometimes gets rid of, or lessens these kind of problems. Just trying to think of the simple solutions to try.
That could be most certainly a mode given the dimensions of the room and the fact that lenght is the same as width. Both axial modes would be coincidental, thus an added undisirable effect at that given frequency. The simplest way to go is corner absorbers, min 10" thick and repositioning the subwoofer in a non simetrical way corresponding to the sidewalls. Say as closer you can from the front wall, but off set from the center. Same goes for left and right. Set them in a way that the measured distances from the walls are a bit different by, say 4". Left will be 3" away of the front wall and 5" from left wall, and the right speaker will be 2" from the front and 6" from the right wall.
You need to have your absorption panels away from the wall makes them more effective how far not sure maybe a couple of inches try it out see what your measurements are
Plus you can have thin absorption panels like half an inch of wool fleece and leave gaps between the panels would work the best better than having one 4-inch absorption panels on its own what the measurement factor I'm not sure tested out. I would have thought it would give you a equivalent to 8-inch panel or more
Try mixing materials up different fibres works better, like with half an inch of fleas half an inch of cellulose foam some natural cotton underlay and with the gaps and to the wall. the different material work better with different frequencies fleece is best for lower frequencies below 100 Hz
Papers good as well that's why they use in offices paper panels or tiles. You could use some office paper panels used as dividers your speakers like a false wall extending the baffle. What I would do Glen some natural wool fleece half an inch folding over and then behind that put the half an inch paper panel would work the best
You talk about fibreglass rockwool is a lot better than fiberglass that's what's used in Studios.
The place them in the Wall in studios to achieve infinite baffle.
You could make your own active absorbers if you place a speaker in a tunnel long funnel just a little slit against the side walls pointing towards your main speakers with DPS you could tune the Frequency to cancel out the Frequency from your main speakers just have to get the phase correct out of phase
Rockwool isn't much better than fiberglass/mineral wool. GIK acoustics and lot's of other reputable companies use ecose mineral wool for their absorbers.
@@C--A I meant sheep wool not mineral wool don't know about the other stuff you mentioned, the sheep's wool is one of the best especially down to 20 Hz or below
@@johnsweda2999 I’ve never found there to be any meaningful differences beyond differences in density and rigidity. Absent a membrane of some kind, a thin layer of any insulation isn’t very useful at these low frequencies.
There has been more recent research on the gap or spacing of panels to test the change in absorption. It was found that argument was a mistake. Not totally, you get benefit to a point, but the assumptions in the original theory turned out to be largely wrong. You can add only up to about 2” of air gap and only if the panel is itself at least 4” thick. If the panel is 2” thick, only 1” gap. Beyond that, there is nothing gained. And the gain isn’t as great as expected. It was originally due to a problem in how we measure absorption in a lab. Once that is corrected for the difference is marginal. On 2” to 4” panels it’s worth doing the 1”-2” gap but don’t go crazy.
@@PoesAcoustics WHY are you suggesting a air gap limit of no more than 2 inches?
@@wa2368 it was based on a study that Ron Sauro did at NWAA labs where he was testing various methods of assessing absorption. He mentioned finding that the airgap was overblown and only effective at a very small amount. He actually told me not to gap panels more than an inch and that the gap didn’t give it the equivalent absorption of a 3” panel per say. I dug a bit deeper with him and ultimately concluded that with thicker and higher density panels it is likely that a 2” gap would still offer some benefit. Given that it’s free. The main point is, don’t think that adding a 2” gap to a 2” panel is going to give you the same absorption performance as a 4” panel would have. It’s not that good apparently.
I can reach out to Ron to see about getting some of the data. I can’t seem to find it publicly now.
I really enjoy these videos, but at the same time i'm often disappointed about your audio quality in these videos. Matthew's binaural mic setup is fun and all, but when they're so close to his earbuds, it's asking for problems. Gene has the right idea, boommic and headphones. And strangely, Anthony's setup didn't cause any problems. I guess he had his monitors volume low enough and maybe a gate on his mic.
Do you guys test for problems before going live?
No this is just the nature of livestreaming. None of us have the time to rehearse prior and many times Anthony and Matt are on location at a client's home and limited to equipment they can use. We emphasize quality of content over production and no fluff. Hope that is compelling enough for you to continue to watch.
@@Audioholics it won't keep me from watching or reading your content. I understand your arguments, however was hoping for a bit more production value. I'm almost positive it would benefit the channel in the long run.
@@martheunen it would but I can't expect guests to.bring equipment needed while traveling.
Guy in the middle smoke some good ganja? lol
Do you have any idea how bad your audio sounds
What?
If only there was a type of speaker that didn’t radiate bass to the sides and top🧐……… oh wait
Ridiculous acronym
I don't get it why Gene needs such huge speaker in that thiny room ,
Solution will be moving speaker from the wall , LOL, it will be huge speaker in front of face ,
Gene you need bigger house or smaller speaker, these guy they don't know what they talking about, very irony solution from experts, 🤣🤣🤣🤣
The room is not tiny st 25ft x 20ft x 10ft. Simply put, these are the best sounding speakers I've ever heard. Go big or go home ;)
The comments in the video about why speakers can sound better when moved away from the walls actually has a lot of engineering and science behind it. One of the key areas is directivity. (secure.aes.org/members/insidetrack/201911/) This is a set of articles going back for over 40 years on this area of acoustical concern.
Another mention in the video why some in wall sound great and others do not is also highly influenced by phase alignments (in the time domain ) and the radiation patterns of the drivers over their operating frequencies.
Good luck resolving your suck out issues...... there are active methods also that can help reduce the issues (noise canceling methods).
Got any references to data or measurements or studies that show the technical characteristics of in wall speakers that create sound stage depth? Grimani says there are some but doesn’t name any, which is unusual for him since he is usually okay with naming names when a company does something well.
Maybe he meant it is theoretically possible or he has heard prototypes but nothing is actually on the market?