Subwoofer isolation pad

[Randall Smith]

Hey guys. I am having problems with my subs vibration transferring to the floor. This is only happening at 45 Hz and down, but it is completely ruining the experience. Anyone have experience with this issue? I am considering a couple different options, a large and heavy piece of granite that will spread the load out a bit or an isolation stand or pad. Any suggestions?

Thanks

 

[RBFC]

I've read about folks using this:

http://www.auralex.com/sound_isolation_subdude/subdude.asp

I have no personal experience with one though.

Lee

 

[Gregadd]

I had this problem with my Janis subs. I solved it with a pair of custom stands from Soundanchors under five hundred dollars.

 

[Ethan Winer]

As I explained in my own forum where you posted, the best way to find out is to have one or two friends lift your sub while you listen and / or measure. If you hear or measure a difference, then an isolation pad will help. Depending on the sub weight, rigid fiberglass two inches thick could work.

--Ethan

 

[Randall Smith]

The sub weighs just under 70 lbs, think the rigid fiberglass would work? How about 2" thick 8 lb mineral wool?

 

[Ethan Winer]

^^^ Probably, but test it first as I described to avoid wasting time on a fix that's not needed.

--Ethan

 

[Randall Smith]

I found some packing insulation from an old sub I used to own. It raised the sub a couple inches off the floor, but will serve well for the experiment.

As you can see in the reverberant graph, my 40 hertz problem was fixed, but under that, it may have gotten worse. I have two more bundles of 8 lb mineral wool, how thick should I make the trap? The thicker the better, right?

 

[Ethan Winer]

The thicker the better, right?

Iso pad, not necessarily. Bass trap, for sure.

--Ethan

 

[rbbert]

If you just want isolation, you should look seriously at Symposium Rollerblocks. You might actually need a bass (subwoofer) trap, though; ASC makes some somewhat pricey ones, or if you're handy there's sure to be a DIY equivalent.

 

[fas42]

Would a piece of viscoelastic material having the right behaviour do the job?

Frank

 

[JonFo]

The problem seems to be room-induced bass modes vs, physical coupling issues.

If you measure and look at the waterfall plot for <200Hz, I bet you will see the sub-40Hz modes pretty clearly.

Bass trapping is one fix you should definitely consider. RealTraps bass traps work wonders on that from personal experience.

It will also require a bit of EQ to remove the final bit. The Audyssey sub DRC box is highly recommend.


And as a final note, physical coupling of subs rarely has much to do with the problem, as a data point, Infinite Baffle subs (like I run) are built into the floor and are part of the structure. Very little energy is transferred to the floor from the 'box', it is air-pressure that causes the floor to vibrate.

Now, some single driver box subs that are too light (and 70lbs is pretty light) can and do vibrate on their feet and generate 'noise' from rattling as they rock back and forth. Isolation pads really do help with that problem. Bolting down the sub to the floor would also address that.

 

[Randall Smith]

I have two more bundles of 8 lb mineral wool that I will install today in the two front corners. Bunched together, this will be 10 " of thickness. I do have 4 Mondo traps in the room. I will move the two mondo traps from up front to another area just to the right and the left of the listening position. Hopefully, this will tame the reverberation times at 20 and 30 hz.

 

[Nyal Mellor]

In addition to the Auralex, Primacoustic have a product called the Recoil Stabilizer which is very effective. Another option is the ball bearing isolation Aurios. I've used both and they reduce coupling of subwoofer vibration to the floor significantly

 

[JackD201]

Hey guys. I am having problems with my subs vibration transferring to the floor. This is only happening at 45 Hz and down, but it is completely ruining the experience. Anyone have experience with this issue? I am considering a couple different options, a large and heavy piece of granite that will spread the load out a bit or an isolation stand or pad. Any suggestions?

Thanks

How is your floor constructed Randall?

 

[hifistan]

One of the reviewers in HIFICRITIC solved this problem but I have not found my copies from where the movers hid them. Anyone else have that issue?