How to cancel subwoofer reverberation.

[Justin Marsh]

I have tried several subwoofers over the years trying to get the right sound. All of them seem to vibrate at the wrong time or cause reverberation on the walls and cabinets around it. I have an acoustically soundproof room. But I didn't consider the wetbar and cabinets I added would cause issues.

My question is is there a device or receiver with tuning mic, that recognizes what frequencies naturally vibrate in my space and either invert them or remove them from the audio signal altogether? I know audiophiles are rolling their eyes, but to me good sound is better than perfect. I like a lot of bass while watching movies on Dolby Atmos, but the vibration of other objects in the theater make a $15k sound system sound like a lowrider pickup with rust issues.

I've been looking for a bandpass filter with mic to put before my subwoofer, but so far no luck.

 

[TheWarrior]

Sound proofing prevents transmission to other rooms, it has little ability to absorb bass.

The wave length of bass frequencies are larger than your room, which means your room is in control of what bass frequencies you will hear, when you will hear them and where in the room you will hear them.

The correct number and location of subwoofers will provide full range bass to your listening positions, but knowledge and high resolution measurements are needed to DIY.

If you can provide acoustic measurements and a complete layout of the room with dimensions and placement of all loudspeakers, we may be able to help. Or you will want to hire a local professional. Good luck!

 

[lovinthehd]

Perhaps you could figure out specific frequencies manually with a tone generator, exciting your new furniture's resonances and then attack the rattles and such on the furniture rather than trying out different subs....maybe even using PEQ to attack those frequencies but I'd attack whatever is resonating first. I find bits of museum putty/blu tac strategically placed can do wonders for bric-a-brac, picture frames, that sort of thing. If I spent enough on a room to sound proof it I'd want to attack the room furnishings rather than EQ/trying different subs. Perhaps you're looking for something from miniDSP.com, maybe a 2x4 unit with a Umik?

 

[Andrein]

Had similar problem myself. My old floorstanding grandfather clock was vibrating with some of the low frequency sounds comming from the subs. Actually looks it was some resonating effect. Isolating clock base from the floor did not help. But i moved my subs a bit and this had an effect. Can listen at the ref level without an issue. Though when my dogs require food and start barking, still clock begins to resonate

 

[highfigh]

I have tried several subwoofers over the years trying to get the right sound. All of them seem to vibrate at the wrong time or cause reverberation on the walls and cabinets around it. I have an acoustically soundproof room. But I didn't consider the wetbar and cabinets I added would cause issues.

My question is is there a device or receiver with tuning mic, that recognizes what frequencies naturally vibrate in my space and either invert them or remove them from the audio signal altogether? I know audiophiles are rolling their eyes, but to me good sound is better than perfect. I like a lot of bass while watching movies on Dolby Atmos, but the vibration of other objects in the theater make a $15k sound system sound like a lowrider pickup with rust issues.

I've been looking for a bandpass filter with mic to put before my subwoofer, but so far no luck.

Nothing will tell you what's rattling, but if you like the sound, I would concentrate only on stopping the rattling. This can be a pain, partially because the sound is hard to locate in many cases- it seems to be coming from one place, but it's actually happening somewhere else.

I have had to do this on some installations and it has saved a lot of time, because the client could never be sure of what music was playing- it was someone else who heard it, then relayed the info to the owners.

Download a tone generator app for your smart phone. I use several-

Tone Generator Ultra
Soundcheck
NoiseGenerator from TMSoft

Tone Generator Ultra has the ability to do frequency sweeps and you can determine the low & high limits, to reduce the time spent waiting to return to the range where you have trouble. You can also change the frequency manually, which is best done after the sweep reveals the frequencies. The sweep speed can be adjusted, too.

You wrote 'reverberation', but what's really happening is called 'resonance'. It could be the drywall/plaster walls, trim around ceiling lights (which I heard yesterday at a project), framed artwork on walls, items on shelves, etc. You can make it easier to locate the source if you cup your hand over your ears and rotate while standing in the middle of the room (do this when nobody is at home). You're hearing will be more directional and sounds from the sides and behind will be less audible.

 

[NINaudio]

It sounds to me like your sub is doing it's job. As other's said I'd consider trying to stop other items from rattling before tuning out sub frequencies. With a wetbar and cabinets you're going to have a lot of things that will all have different resonant frequencies and you may end up having to tune out quite a range of frequencies.

 

[Justin Marsh]

Yes, 'resonance'. Was the word I was looking for. The natural frequencies that certain items vibrate at. I grew up in Seattle. I remember the Tacoma Narrows Bridge. A wind gust resonating at the same frequency as the bridge caused it to collapse.

Is there nothing out there that creates a simple bandpass to filter 'resonance' ? This seems like a cheap fix. Are there articles about this very problem? New cars can invert road noise, why can't an advanced home theaters eliminate resonant low frequencies?

 

[Justin Marsh]

Interesting article on something called Bass Management, but from the readings it's more of a theory and not currently integrated or used in even higher end systems.

https://www.soundandvision.com/content/bass-management-and-lfe-channel

 

[lovinthehd]

Interesting article on something called Bass Management, but from the readings it's more of a theory and not currently integrated or used in even higher end systems.

https://www.soundandvision.com/content/bass-management-and-lfe-channel

So I take it you don't have any? Could be part of your problem?

 

[mtrycrafts]

Interesting article on something called Bass Management, but from the readings it's more of a theory and not currently integrated or used in even higher end systems.

https://www.soundandvision.com/content/bass-management-and-lfe-channel

That bass management is not to stop objects from resonating in a room.
Your issue is that your new addition is not well secured and will resonate at different frequencies.
Glass in a wall cabinet can be better secured with
https://woodworker.com/panel-retaining-clips-statuary-bronze-mssu-165-959.asp
I use it. Other items in the cabinet needs to be secured or isolated especially if you have glass shelves.
start by trying some napkins under things and see how it works.

Or, final solution, disconnect the sub.

 

[lovinthehd]

Well, without bass management he may have sufficient overlap to increase resonance levels....