# Seeking opinions on subwoofer isolation devices



## 2gumby2 (Nov 23, 2008)

I was wondering about the merits of subwoofer isolation devices such as the one in the link below. My subwoofers use the typical spikes, but I'm curious about what benefit subwoofer isolation devices might provide. I have 2-channel music only systems.

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


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## drdoan (Aug 30, 2006)

Any coupling of sound from any speaker that is transmitted to the floor can interfere with the purity of the sound. If the speakers' cabinet is made properly, that will be a minor issue. I guess the only sure way to find out is to order one with a return policy to your liking and try it. Have fun. Dennis


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## eugovector (Sep 4, 2006)

Elemental designs is also working on a similar product. Drop them a line and you'll probably find their less expensive and better constructed than the Auralex.
_Posted via Mobile Device_


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## dyohn (Apr 17, 2008)

I can vouch for the Subdude as a quality product that is effective.


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## Kal Rubinson (Aug 3, 2006)

2gumby2 said:


> I was wondering about the merits of subwoofer isolation devices such as the one in the link below. My subwoofers use the typical spikes, but I'm curious about what benefit subwoofer isolation devices might provide. I have 2-channel music only systems.
> 
> http://www.auralex.com/sound_isolation_subdude/subdude.asp


I think it works very well. http://www.stereophile.com/musicintheround/1204mitr/index.html

Even better but much bulkier is the ASC Sub Trap: http://www.stereophile.com/musicintheround/904music/index1.html


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## benbboy (Aug 29, 2010)

I bought the elemental designs isolation pad for my a2-300. I must say, it has definitely had an effect on the overall sound quality. I don't want to attach numbers, but the output seems to have increased some, the bass has tightened up significantly and I still feel the rumbles (so do my walls). I'd give it a go.


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## XEagleDriver (Apr 15, 2010)

*Also check out the Gramma line*

Depending on the size of your sub, a *Gramma* or *Great Gramma* may be a better fit. I use a Gramma with my SVS PB-10 NSD, it is the correct size and I highly recommend it.

http://www.auralex.com/sound_isolation_gramma/sound_isolation_gramma.asp

In my case, the theater is upstairs, and the Gramma stopped the dry-wall pops I was getting over the dry wall nails/screws in adjoing rooms--not a popular side effect with my very patient wife! 

The improvement in the bass sound quality was noticable and an added bonus to not getting the system shutdown. 

Cheers,
XEagleDriver


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## edgebsl (Oct 1, 2010)

I second the suggestion of elemental designs. They have some great cost effective solutions.


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## bambino (Feb 21, 2010)

I'm with you guys on using ED they are a great company and good folks to do business with and will do anything you need.:T


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## LF911 (Mar 30, 2010)

I have an eD pad for my A7-350.....much beefier than the Auralex stuff. Plus it looks better.

eD can custom cut them for any dimension. Give them a call.


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## salvasol (Oct 31, 2006)

Does anybody think this  ruber isolator  will work with a sub???


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## LF911 (Mar 30, 2010)

eD puts something like this on their subs...although a post is first screwed into the cabinet, then the isolation feet get screwed onto the post. An iso pad works better....IMO


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## Andre (Feb 15, 2010)

My DIY thoughts:

items needed:
1 x old rubber garden hose
1 x piece of 1/2 inch plywood 
2 x pieces of 2/4 spruce
1 x tube construction adhesive
1 x piece of black cloth

-Cut the plywood to a little bit bigger then the size of the subs base dimensions.
-Cut 2x4 to size to make two full lengh feet the same size as the plywood
-Cut up the hose so that you have 3-4 pieces the same lenght as the 2x4s (3-4 pieces each foot)
-Glue the hose pieces down to the 2x4s then glue the plywood to the top of the hose pieces
-throw black cloth over uglyness, tuck and staple

Tada


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## LF911 (Mar 30, 2010)

Acoustic foam is used in both the Aurelex and eD iso pads....don't know if garden hose is a good substitution. Did you seach diy isolation pads?


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## Andre (Feb 15, 2010)

WOOT Even cheaper.

My DIY thoughts:

items needed:
1 x piece of 1/2 inch plywood 
1 x pieces of 2.5in foam insulation
Some type of Glue
1 x piece of black cloth

-Cut the plywood and foam to a little bit bigger then the size of the subs base dimensions.
-Glue the plywood and foam together
-throw black cloth over uglyness, tuck and staple

Tada

And this is only needed if your sitting your sub on a hard floor. Carpet and underpad will effectively decouple
the sub from the floor. Other acoustically absorbant material will do.

Rubber (as long as its not too hard)
Foam


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## salvasol (Oct 31, 2006)

I found this picture online, somebody is using this pads ........


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## Owen Bartley (Oct 18, 2006)

Seems like there are a few more options for these recently. I guess all would have a similar effect, but it would be interesting to see a direct comparison. It's funny that I just posted in a thread about spikes for towers which I think increases the coupling, and now here I am in a thread about isolating subs 5 minutes later.


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## Andre (Feb 15, 2010)

I think you would want spikes for all floor standing speakers EXCEPT subs so that it would enhance their bass properties, including those on stands


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## WmAx (Jan 26, 2008)

Actually, you do not want spikes on any speaker, except for the purpose of 'stability' on some circumstances. You want to isolate/de-couple the main speakers and subwoofers, ideally.

As for using foam for de-coupling, only certain foams are suitable. Most foam radically changes in compliance and stiffness and even shape with constant pressure applied. Standard grade cushion foam is worthless, for example. But you can order suitable foams online. Latex foam is superb for this purpose, and not quite as good but cheaper, Evlon foam. Even cheaper, and a little worse, high-resilience foam. http://www.foamonline.com/ is a great source for custom foam types and shapes cut to order. However, lead time can be 2-3 weeks from time or order to actually receiving the product, so schedule project accordingly.

Chris


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## Andre (Feb 15, 2010)

Would you consider the foam in the picture above "standard grade cushion form"? IF so, I will put in my 2 cent to say hogwash, the exersice mats you get for Costco such as those above a totals sufficient to decouple a speaker from the floor unless the speaker is so heavy as to total compress the foam, in which case you can add another layer.

I beleive that coupling a small speaker to the floor via a stand and spikes "can" help with "felt" bass if no subwoofer is being used.


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## callas01 (Oct 24, 2010)

for $50 why not just buy the SubDued or Gramma or the eD built risers.


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## Andre (Feb 15, 2010)

To each there own, I would rather pay $20 for 10 foam squares, use what I need, trim the edges, add a nice sticker "Andre's supereme isoelastic issolation pads" and hand the other 8 our for xmas presents saving mayself a boat load for the year.


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## WmAx (Jan 26, 2008)

Andre said:


> Would you consider the foam in the picture above "standard grade cushion form"? IF so, I will put in my 2 cent to say hogwash, the exersice mats you get for Costco such as those above a totals sufficient to decouple a speaker from the floor unless the speaker is so heavy as to total compress the foam, in which case you can add another layer.
> 
> I beleive that coupling a small speaker to the floor via a stand and spikes "can" help with "felt" bass if no subwoofer is being used.


I can not possibly know the actual foam type/parameters from a picture. But the majority of said foam products are not stable for long term use. Their properties will change(for the worse) with extended periods of time under load. Specific foam types are required to keep somewhat stable properties under such conditions. Of course, if you simply used a very large surface area of very stiff foam (for example a standard exercise mat cut to shape under the load), then it's resonant frequency and over-all compliance in reaction to the load would be poor. That is, the ability for the mat to give in to movement and the high pass frequency of the spring, would not provide significant de-coupling.

There are all sorts of ways to do this effectively without having to use foam as the actual spring component. Actual metal springs are a good option and even repelling magnets. One could then place a medium compliant foam between the space under sufficient pressure and with enough surface area relative to load, to act only as a damping mechanism, thus freeing it from the stress and parameter changes that would occur if it was used as the actual spring mechanism to support the load.

Chris


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## Andre (Feb 15, 2010)

Up to the individual I guess. I have borrowed a Auralex and heard/felt no difference between it and a exersise mat. I can understand that long term the exersise mat would loose its spring and need to be replaced (depending on the heft of the speaker). So, in the case of a custom install wear the isolation pad would be difficult to replace I could see using higher end material.


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## eugovector (Sep 4, 2006)

WmAx said:


> Actually, you do not want spikes on any speaker, except for the purpose of 'stability' on some circumstances. You want to isolate/de-couple the main speakers and subwoofers, ideally.
> 
> As for using foam for de-coupling, only certain foams are suitable. Most foam radically changes in compliance and stiffness and even shape with constant pressure applied. Standard grade cushion foam is worthless, for example. But you can order suitable foams online. Latex foam is superb for this purpose, and not quite as good but cheaper, Evlon foam. Even cheaper, and a little worse, high-resilience foam. http://www.foamonline.com/ is a great source for custom foam types and shapes cut to order. However, lead time can be 2-3 weeks from time or order to actually receiving the product, so schedule project accordingly.
> 
> Chris


What do you use? The Latex foam from Foamonline.com? What firmness/thickness?


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## WmAx (Jan 26, 2008)

eugovector said:


> What do you use? The Latex foam from Foamonline.com? What firmness/thickness?


If the cabinet is of moderate mass, you can use the latex foam. Pick the maximum firm value and use 1" thick. The high resilience foam is also good, and can be acquired in higher firmness value, and can support more mass. For lower mass cabinets, use a medium firm value. Keep in mind the firmness vs. mass is relative to the surface area of the flat contact surfaces/foam surface area.

The big Auralex pads like the Gramma actually don't decouple all that well in most cases for low frequencies when using a low mass cabinet; the resonant frequency will remain relatively high. I adjust suspensions to have a very low resonant frequency that is under the passband of the speaker.


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## recruit (May 9, 2009)

I had custom made isolation platforms for my 2 DD12's that I had but the subdude by Auralex is an excellent choice, especially if placing a sub on a wooden flooring or tiled surfaces.


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## Chris--- (Dec 27, 2010)

What about the cheap and easily available antivibration mats available for washing machines ? You get a 2cm thick rubber mat that decouples low frequency in many sizes (even 200x60x2 for a big sub...)


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## ojojunkie (Jun 23, 2010)

Can I add this question, Anyone have tried those pads on downfiring subs?


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## Irishsaab (Jan 26, 2011)

I don't know if any of you are interested but I thought I post this anyways: 

DIY subwoofer isolation pad: after much research and reading the "experts" opinions, I decided to save myself some cash and have some fun building my own pad. Pretty simple really: buy some 3" or 4" foam at Joann Fabrics (when it is 50% off; the stuff is uber expensive otherwise) and some simple fabric to match your decor and/or flooring, buy or dig up in the workshop a piece of wood (thicker than 1/2" and preferable MDF) that has the same footprint as your sub. Lay the wood over the foam, cut foam to same footprint, cover both with fabric and Ta-DA! :T One DIY subwoofer isolation pad!


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## drdoan (Aug 30, 2006)

Great tip. Thanks. Have fun. Dennis


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## Irishsaab (Jan 26, 2011)

Just adding my 2 bits a bit late in the game. 

I looked at the subdude and other such devices and thought "hummm I could make my own". So after some research and lots of forum reading I when shopping. Shopping list: 4-6 inch upholstery foam, fabric to match carpet floor and piece of plywood (ended up using an old solid cabinet door that so happened to make my sub's foot print). Johann Fabrics had a sale on the foam (only time that the stuff is reasonable) and I bought enough to fit foot print. Found some material that was also on sale and was a close match to my carpet. 

Took it all home and within 10 mins I had my sub isolated and looking like a custom install. Definitely worth the time and now I can include custom install on my future resumes. LOL


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## diggles (Jul 23, 2010)

eugovector said:


> Elemental designs is also working on a similar product. Drop them a line and you'll probably find their less expensive and better constructed than the Auralex.
> _Posted via Mobile Device_


What is the assumption of superior value based on?

I suppose for me Auralex is a proven entity in the category.


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## typ44q (Apr 7, 2008)

I use one of the Auralex subdudes under my A2-300 and it works great, it made a noticeable improvement to the sound quality. 
I have not seen one of the ED ones but the Auralex one is well made, not that you really even see it once the sub is sitting on it.


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## Andre (Feb 15, 2010)

Still think these things are hype. All you want to do is decouple the sub enclosure from the floor. If you have carpet and underpad that will do. The only time I may see a need is if the sub is on a hardwood floor which is coupled mechanically (nailed) to the subfloor.  Then IF the floor rattleing bothers you, you can go to Home Depot and buy 2 squares of MDF/HDF, a square of high desity foam insulation and some rubber feet. If thats too "ugly" wrap it in cloth matching the color of the sub.

Ok there are some exceptions to the carpet and underpad. If the subs sheer weight compresses the underpad to nothing, or if sub cabinet vibrates like a "magic fingers" hotel bed, then you may feel a difference with the iso.


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## gorb (Sep 5, 2010)

I'll chime in here. I recently purchased an auralex gramma for my outlaw audio lfm-1 ex. I have not heard any difference. I'm still happy with the purchase though because I was scared that the driver would be hitting the carpet, and i won't have that issue with the gramma


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## diggles (Jul 23, 2010)

They're not expensive enough to be hype. Plus, they're easily DIYed to further reduce cost if you're so inclined.

Could be that your environment simply doesn't need one for maximum performance. Many venues and homes do though, and this is an easy fix. YMMV is always the rule when tweaks are applied.


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## Andre (Feb 15, 2010)

The green highlighter around the edge of you CDs wasn't expensive either...still nonsense though


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## Irishsaab (Jan 26, 2011)

If any of you have a wood frame floor over a crawl space then you will experience what I did with my sub! Not only was I watching War of the Worlds I was on the set! Crazy shaking and vibrations! After the DIY subdude was installed I still had the awesome real to life movie experience; minus the earthquake! :R


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## diggles (Jul 23, 2010)

Andre said:


> The green highlighter around the edge of you CDs wasn't expensive either...still nonsense though


Bad comparison. Pro audio guys use Grammas and their cousins without second thought. Tired of everyone assuming that all gear and acoustics is perfect because they plugged in their little room EQ mic and pressed the start button.:doh:



Irishsaab said:


> If any of you have a wood frame floor over a crawl space then you will experience what I did with my sub! Not only was I watching War of the Worlds I was on the set! Crazy shaking and vibrations! After the DIY subdude was installed I still had the awesome real to life movie experience; minus the earthquake! :R


Isn't the quaking part of the fun in some cases?:devil:


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## Andre (Feb 15, 2010)

I can see where a decoupling device will help Irish if he doesn't like the earthquake, if however you are a prerson that does like it then I would use the same device but to isolate your electronic equipment from the vibration. Still don't understand the point in buy somthing that you can make for 1/3 the price. Make it if you need it, not to say you have one. I have an even worse opinion of $500 aftermarket power cable, even though some swear by them.


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## diggles (Jul 23, 2010)

Andre said:


> Make it if you need it, not to say you have one.


Either way, his call.



> I have an even worse opinion of $500 aftermarket power cable, even though some swear by them.


Not related, but good to know.:scratch:


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## tesseract (Aug 9, 2010)

Discussion will only take you so far. Isolation devices can and do work, but not everyone needs them. They are made to fix problems, if you have problems such as the room buzzing or neighbors to consider, then try them out to see if they work for you or not. 

I have a suspended hardwood floor over a crawlspace. The floor ripples nicely (an effect I like) but it was feeding into the walls, making the room and even the ceiling buzz.

I put 16 x 16 x 3/4" rubber floor decking tiles under my subs. Kept the floor ripple while pretty much eliminating wall/room buzz. Cost, $10 total, and I've seen them for only 2.50 each recently.


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## diggles (Jul 23, 2010)

tesseract said:


> I have a suspended hardwood floor over a crawlspace. The floor ripples nicely (an effect I like) but it was feeding into the walls, making the room and even the ceiling buzz.


I know, the floor thing is something I'm not anxious to lose LOL


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## 2gumby2 (Nov 23, 2008)

I ended up making my own with some 3/4 inch plywood and some high density foam from the local hardware store. Turned out just fine.


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## ejbragg (Dec 13, 2009)

Irishsaab said:


> If any of you have a wood frame floor over a crawl space then you will experience what I did with my sub! Not only was I watching War of the Worlds I was on the set! Crazy shaking and vibrations! After the DIY subdude was installed I still had the awesome real to life movie experience; minus the earthquake! :R


That was funny, dude!


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## sportflyer (May 2, 2010)

Guys be careful how you select your vibration isoation pads. Check out this sorbothane website. http://www.sorbothane.com/ There is a calculator in the design guide . Play around with the calculator variables by imputing various pad sizes and thicknesses and you will see that you could end up with _ve isolation if you are not careful. I have found that using .5 inch thick, D70 Sorbothane seems to give the best results. Please note the load is per pad so if you use 4 pads then divide the total weight by 4 . Best place to buy sorbothane sheets at very reasonable prices is McMaster.


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## sportflyer (May 2, 2010)

Hi guys , 

Over the last week , I built a Riser from concrete slab and brick as legs. Legs are attached using construction adhesive . It weighs 56 lbs 









I have not covered it yet . This Riser is for a SVS 12 inch cylindrical subwoofer. 

My plan is to place the subwoofer on the platform and place 3/4 inch thick Sorbothane pads between the legs and the wood floor as isolators .

An alternate arrangement is to invert the table and place the slab side towards the floor again using sorbothane pads as isolators and use the legs to support the subwoofer. 

I am not sure which is the better arrangement .

My question is whether I should spike the subwoofer to the concrete slab or use the rubber feet that I am currently using ? 

Your advise needed before I go about messing with this heavy riser .


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## drdoan (Aug 30, 2006)

Usually spikes are for carpet, rubber for solid services. Have fun. Dennis


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## sportflyer (May 2, 2010)

I just found out that the newer SVS Subs don't come with capability of spiking them ie no holes with threads for spikes. I dont think I want to drill the base and put screw inserts for the spikes. I will just place the Sub as it is on the stand.


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