Ep. 43 - Easily fix SUB HUM and clean the signal | Home Theater DIY Subwoofer |Home Theater Gurus
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- Опубликовано: 10 ноя 2020
- Keep your subwoofer signal as clean as possible. Subwoofer HUM Hack. If you've tried cheater plugs and still have hum do this. Even if you don't have hum use it to keep your signal as clean as possible! Block the Home Theater sub Hum!
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Hammer Play list
• The Hammer
Sub setup and issues playlist
• Bass Setup and issues
Recommended tools
Umik-1
www.amazon.com/gp/product/B00...
Optional mic
Dayton UMM-6
www.amazon.com/gp/product/B00...
Mini DSP 2x4 HD
www.amazon.com/gp/product/B01...
USB extension cables
www.amazon.com/gp/product/B06...
XLR to RCA for output of MiniDSP to input of Behringer amps or any amp with XLR input
www.amazon.com/gp/product/B00...
Sub out on Processor or AVR to MiniDSP input.
www.amazon.com/gp/product/B07... 
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I just want to say thank you! Ive been dealing with this hum from my subs for a while. Ended up buying a Furman noise isolator surge protector and the hum still was just as loud, finally got a chance to do this on my dsp and wow 😲 instantly gone! I appreciate you putting these videos to help us all! ❤️
That's awesome!!! So glad it was able to help!
Thank you Steve for this simple trick!! Using a 150hz HPF removed a hum in my left sub and a null in that frequency range that was driving my crazy. 👏🏼
Great video Steve! I had hum when I connected subs to a crown amp. It was coming from my cable line. So I connected cable line through my power conditioner and it went away. I cant wait for your audessey video because I just got the app. Keep up the great work.
Thanks DD!
Many many thanks for this one, my DVB-C provider changed something in out block and now I get such crazy sub hum that I ended up unpugging the cord... On the other hand I have just recieved my miniDSP 2x4 to compliment my dual subs, and rewatching your bass management related episodes, when I accidentally bumped into this one. Definitely will give it a try.
You're welcome. I hope it helps!
Great video Steve, thanks for sharing. This is exactly what I do to eliminate the noise in my subs/inuke NX6000. LPF BW 48db 👍
Thanks. Works great.
You.are back awesome
Yep I'm still around. Build updates will be ramping up in a few weeks.
Thanks for this!
Thanks for the tip man, very helpful.
You're welcome!
Great info and just what I needed. I have a mini dsp 4x2 HD and a Behringer app and have the hum.
Thanks Michael!
What a great tip, thanks for that!
Thanks Mike, glad it helped.
I would much rather remove an unwanted noise but this is nice if you are at ur wits end. Thanks
My parasound does this for my mains. The solution to use a 3 prong to 2 prong defeated isn’t a good idea but it fixes it.
Great video! I would like to know if you have commented on the performance or sound of a 15 or 18" DIY sub. I saw a video or two but you have not said anything about how they sound in comparison to other DIY or off the shelf subs.
@ Home Theater Gurus you make really good, informative videos. can you tell me which minidsp2x4 plugin i need if i have 1 activ subwoofer that is behind me. maybe a second activ subwoofer will be added at some point.
Nice! Never considered doing that to get rid of hum! I always take the machete/sledge hammer approach. This is something I'll have to try next time!
Yeah it's definitely one of those "why didn't I think of that" things.
Watched your video and great info... I have subwoofer hmmm and like a clicking noise when it's not even plugged into the AVR. It works, but when everything is cut off but the sub you can hear it. The thing is so heavy it's gonna suck to box it up and return... any suggestions?
Whats a good hdmi cable you'd recommend? For 4k because I have a hum too but I'm pretty sure its because I'm hooked up to a htpc and I used like 9$ hdmi
Nice
Thanks
60hz hum in a sub is a PIA to clear. Glad to see you are doing well. I like your home plans and that you are using a steel frame. Wish I could be there to help weld it together with ya. All the best!
Thanks Kevin. It's got a roof now. Framers will be on site in hopefully 2 weeks and after that I'll be really busy and begin build update videos.
@@hometheatergurus Steve, keep the vids comin'. I really like the new intro, although it might be a tad loud and may shock a few folks. Me, I'm always happy to hear the Guru BOOM. May the blessings be many on your family and new home.
I get speaker hum regardless of volume. As soon as it's turned on it is really quite loud. Even with volume at 0
Hi, am sreejith from Kerala, India. Thanks for your video. Please do a video about "How to fix screen and projector"
Any recommendations for my Crown amp humm?
Great stuff always. How would you deal with hum/static over the Atmos channels that are on a power amp?
Sometimes it's due to the speaker wire running to close to a power wire. You can also try running a wire from the amp rear screw to the avr or processor rear screw to go round them together.
@@hometheatergurus That's a good idea I'll test that. Cheers
@@hometheatergurus Steve, should it be safe to wire two amps to the AVR's ground screw? I have two amps that have pretty bad hum, an old Rotel 6 channel that runs the overhead atmos speakers and the NX3000 running the subs. Will these be safe to connect them both the Anthems' ground screw? Thanks
My Inuke3000DSP has a hum but I've always had a lowpass on it so it was never a problem. Mine is from my computer whenever the GPU is doing something intensive. The harder it's working the louder it is, but the lowpass filters 95% of that out. Also have a slight 60Hz hum also mostly when the GPU us being used heavily, but it's so quiet you need a dead silent room to even notice, thankfully a non issue.
In the living room though... amp/sub is unusable. Didn't bother to try and eliminate the hum beyond a cheater plug, was just bored and seeing how that room sounded with a sub. Needless to say I never found out haha.
Yeah sub hum can be a pain in the sub!
I've got the same problem with the video card but the noise comes through via the overhead channels because those are on an older Rotel amp. It is extremely annoying and so far nothing helped.
I have the same issue when using my behringer A800 with the preouts of my Yamaha TSR-700 reciever to power my front L/R speakers. I have tried using a XtremPro Hi-end Ground Loop Noise Isolator/Filter I bought from Amazon ($25) and it eliminates all the graphics card variable noise, but I still have a static noise that I can hear when the room is quiet. So is this an issue for most external dedicated amps when connected to a PC/TV earc, or just the cheaper Behringer and Crown amps?
@@Povell81 I think it's just the nature of some pro amplifiers. My mixer (used for a mic to my computer) also had lots of noise but I got rid of most of it with a cheater plug thankfully.
You might be able to get rid of your static noise by turning up the volume on your pre amp and turning down the volume on the Behringer. Basically more input voltage to overcome the other noise the amplifier has. Letting you turn down the volume knobs (voltage attenuators) and lowering the overall noise floor.
Living in temporary camper it may not be soundly grounded to earth. Can always use additional grounding and stick ground in the earth outside and maybe move it about and then attach to the power board earth/ground to see if it grounds the hum.
Also maybe dodgy hdmi as hdmi is always dodgy even those 4k are dodgy with dodgy 2.1 that is epic fail. Maybe the dodgy hdmi has break in the pin on the inside of the equipment an open circuit on the ground. Can always grab a wire cable length and attach it to another ground elsewhere then attach to crown ground to see if the hum is grounded.
Also its not a sub hum as it would apply to all amplifiers. If its a sub hum then does it hum if the AVR AVP output lead to input lead to the amplifier is swapped around if the hum goes away then there is broken ground one of the outputs on the AVR AVP RCA or XLR or DB25 connector.
1:34 35dB ground hum that is rather high. I had noise filtering though one of the outputs to inputs for proper Dolby Stereo playback that passed from Laserdisc to the Denon AVC-X8500H input then outputs to Behringer DEQ2496 where I could see this -75dB noise. It took little thinking and solving it with a Behringer hum eliminator that eliminated the noise I forget how far down it reduced it to maybe below -120dB or somewhere around that figure which is acceptable since most any audio gear is gong to have signal noise ratio S/N ratio typical to must audio equipment.
Thou the crown only shows level down to -70dB I wonder if it can have a remote software connected via computer where the remote software will show a much lower dB scale reading below -100dB to see what the amp is like with no lead connected to it. As leads act like an antenna aerial, depending on how good the cable is with its shielding to reduce minimize RF EMI radio transmissions, other electrical noises. How good is the filtering in the amplifier or AVR AVP as they all have filtering to reduce RF EMI as much as possible when they build and test this in Anechoic Chambers that are not just for testing speakers but also RF and EMI.
You can also use REW to see the frequency of the noise of the random noise frequencies as well as how low down in the dB scale it is. Disconnect the lead on the computer for REW , there be a typical noise on the REW that I think is -110dB or lower. Connect something up the signal noise goes up and often shows random frequency noise. Put a sine wave tone though it which can be adjusted to very low -dB level below the noise and increase the generated sine wave level of say 1KHz, get the idea?
That system isn't in the camper. There's no way I'd get away with a hammer sub in it.😁
I don't even use the system in that building it was just temporarily setup for an audyssey setup video. I'm glad I had the hum as it was a perfect opportunity for the video.
So what brand was the defective cable?
Dollar tree.. 😁
I want to know what's up with that software. That looks nothing like the software I have for my 2x4HD.
Yeah its the standard 2x4 software not the HD. Does the same as what you have it's just laid out a tad differently.
@@hometheatergurus Got it. Thanks for that. That version looks like it has a much nicer GUI.
@@_Radius_ agreed. I like it better than the HD plug in too. I'm not sure why they don't use one gui for both types.
@@hometheatergurus Yeah that doesn't make much sense. I have never used a standard 2x4 so that's why I didn't realize it was different. Now I know. :)
When the new build videos dropping??
Metal Frame and roof are done. Framers are about 2 weeks out. That's about when update videos will start.
Again, just for DIY subs correct?
Yeah pretty much. A sub with a plate amp has basically has a lpf too which is the crossover knob which we max out as the avr handles the crossover. That knob can be used as well although most of those knobs max at 200hz or so. This means when maxed its filtering above it so you're doing the same thing. Now if you have a switch that disables that knob you aren't getting the filtering benifit.
There’s another way. If you have a unused RCA out on your amp, connect that with a coax cable or RCA cable and plug it in the low level input (not LFE) of your sub. The hum will disappear.
I'll have to try that. Thanks!
This is only applicable if the hum matches something that an HDMI cable would create. If you have a ground loop hum at 60 Hz this will not help you with that.
That is true.
Setting a 140hz or even 160hz LPF filter isn’t ideal. It’s too close the the 120hz LPF that they AVR LFE output typically applies and they may interact in odd ways. I’d recommend grounding the amp chassis to the ground plug on the AVR, and perhaps to the electrical outlet as well. I’ve seen where you might need to lift the ground on the TV or projector as well using a cheater plug (if comfortable with such).
I'm not sure if you watched it but we're using a very steep filter as to not effect anything around 120 hz at all.
And yes there are other methods that sometimes work sometimes don't. This is just one and something that IMO should be a default setting as it doesn't do any harm and actually filters unneeded frequencies.
@@hometheatergurus ah. But it does. Your AVR likely has a shallow 6dB or 12dB per octave roll off at 120hz. That means by 240hz it is only 6 or 12 dB down. (An octave is a doubling of Hz). So your steep roll off filter at 140 or 160hz is almost certainly in conflict with the AVRs shallow roll off and this may introduce phase issues in that overlapping region. You could check if it does by doing a full bandwidth frequency response with your main speakers playing as well with the Filter you created at 140Hz-160Hz on and off and seeing how the frequency responds in that overlap.
@@jvonengeln Lfe is 120 hz max... No content above it. Our crossover for bass management is usually 80hz. Thanks for the input.
@@hometheatergurus it isn’t a brick wall filter on an AVR at 120hz for subs high cut - so yes there is plenty of content above 120hz, though yes it is being shelled off. AVRs use a shallow rolloff filter. Case in point here is my subwoofer frequency response on a Denon 4520CI with the default 120Hz subwoofer LFE setting. Mainspeakers turned off for the capture (but crossover setting at small and 90hz) Post 2 of this thread near bottom. www.avsforum.com/threads/the-subwoofer-recommendation-by-pricepoint-thread.1425179/#post-22318562