Home Made SubDude and Speaker Stand Risers

[BriDown]

Hey all, thought I'd share a couple home projects I have been working on. I have read a good bit about Aurlex's SubDude HD. From what I read, their function and outcome are controversial. In my home, my living area and kitchen are on big great room. Not the greatest for AV Systems, but its what we got, lol. Between the kitchen and living area is a short hall to the dining room, right off that hall is a bath. When my system is on, I hear lower bass in the bathroom then I do in the living area. My floor is carpet over plywood. Below is an unfinished basement with everything exposed. So I thought I would try a SubDude, but instead of buying one, I would make one. Materials- 3/4 MDF, Roxul ComfortBatt R-15 Unfaced, Performix Brand 11oz Plasti Dip and 4 inch pressure treated finials. From all my research, the MDF, Roxul and Performix have sound deadening and isolation properties. Exactly what we want- isolation and a control of resonant sound. There was specific batting for Sound, but that was way too expensive. We built the top 2 inches larger all way round than my sub. Below it, we eclosed a little over 4 inches to house the Roxul. The Roxul was 3.5 inches think. We were able to cram 3 layers into our enclosure with pressure clamps. We attached the bottom and legs. Then started spraying it with the Performix. The pic shown has 4 coats. We plan 8. Here is our creation:

It is a little taller than I had wanted, but to achieve what I wanted it needed to be.

My next project. I have a set of Sanus BF31's. I moved my speakers and as a result the left speaker was partially blocked by the couch back. Roughly 5 inches. I do not like the adjustable metal stands, just my preference. What to do? Build a riser, lol. Again we used 3/4 MDF. Purchased 7 inch decorative leg stands from Lowes and set to it. We wanted to angle the legs out from each corner for added stability. We added 1.5 inches all the way around, almost .5 taken back from the route. We angle drilled underneath to attach the legs- which we had to cut the top at an angle to get the outreached legs. We replaced the preinstalled screw with a double sided wood screw and attached it as well as glued it. The shape of the platform perfectly matches the Sanus' base with the same route. All that needs to be done now is to paint it with Satin Black. The height will be perfect. Consider the head of the leg partially cut, the recess of the drilling on the the platform and it should stand almost perfectly above my couch back.


Thanks for looking and letting me share.

 

[j_garcia]

How are the feet connected in the first one? I don't think the feet are necessary, but it doesn't look bad. I guess we will see how it works out.

 

[BriDown]

The feet were attached to the bottom and before it was secured. They had pre-installed screws. We matched it with a nut, tightened securely then cut the remaining end of the screw off so it wouldn't impede on the batting making it pinched in those areas.

I hear ya on the feet. I wanted it lifted off of the carpet and more importantly, my wife didn't just want it to be a box on the floor. I thought the legs made it look more 'furniturey' and it made her pleased with it. They are purely aesthetic.

I too am curious to see how it works out.

 

[j_garcia]

So is there a layer of foam separating two layers of wood? A subdude is basically a platform sitting on a piece of foam. The foam eliminates the transmission of vibration into the floor.

 

[BriDown]

There is the top platform, attached to it are 4 sides and a bottom. The interior is filled with batting. The MDF barely resonates, the batting absorbs the rest. As for the legs, I respectfully disagree. Having no legs means the base lays flat on the carpet. IMO, a simple Subdude, according to specs and reviews, does not have adequate materials and design to accomplish its claims. That is why the debate. I am making no claim mine is better or will even work. But I will speak to the legs. If the 'box' Sat directly on the carpet, it would be dynamic. Although we wish all vibrations would be eliminated by similar constructs, they are not. The box sitting on the floor equally distributes its weight. Per square inch, that is not much. The box is dynamic because it is in constant motion on top of the carpet. Carpet fibers vibrate because of the bleed through and the distributed weight. Now legs. 4 legs have a very dense and concentrated area of weight. The surface area to vibrate is not only minimalized, but it is almost removed. Move your sofa or a chair- indentations in carpet densely packed. My sub weighs 30lbs, add the weight of the sub box then distribute that to an inch on each leg. Compression and little vibration. On a construct like a Subdude or similar the greater surface area of contact is a weakness, not a strength.

 

[BriDown]

John and I have been talking behind the scenes about this project and its possible outcomes. Although he will probably be right, I hope he is not, lol. Decided to input those conversations, with his permission, as there is a lot of good info combined with fundamentals of sound. I am a complete newcomer to the world of AV. In the past I bought Boxed Systems and thought that good enough. This is my entrance, one where I have tried to read a lot and learn often time left confused because I couldnt keep the different info straight. I appreciate input, ALL input. It helps me.

Default Riser

3/19/2014
Would rather send via PM, but can do it in the thread if you like. Don't want it to sound like I am being a jerk about it because we don't agree on the subject.

I don't agree with your assessment. You are talking about coupling not decoupling. They are two completely different things. In the case of a sub which is generating both vibration from the driver creating sound AND force exerted on the cabinet by the driver moving. IMO, you don't want COUPLING for a sub. The batting beneath the riser isn't doing anything either. In regards to the legs, all they do is give smaller points of contact, but they still transmit the vibration, though the frequencies that are transmitted are likely modified, vibration still gets through. Tap a piece of wood with a hammer and see how much vibration is transmitted to the surface beneath. Then do the same with a stack of your batting.

Greater surface area of contact? It is FOAM - foam chosen specifically for absorbing transmitted energy (why else would they ship sensitive electronics packed in foam?), thus it does not transmit that energy to the contacting surface. I've worked on engineering projects for moving machinery required controlling vibration and noise both for the equipment itself and for those working around the equipment.

My sub weighs 147 lbs and does not transmit vibration at all because of its design.

-John
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Default Re: Riser

3/18/2014
Hey John, in no way did I think you a jerk. Actually, the opposite. Judging by your number of posts I think it is safe to assume you have been in this game for a long time and possess considerable knowledge as well as experience. I can learn from that. But, that doesn't mean I don't have my own thoughts based on my research and understanding of my project and what I want it to accomplish.

I chose my products carefully: Roxul Paperless (just means no paper on one side of insulation) Stone Wool Insulation r-15. Rock Wool is highly recommended because of its high absorption qualities of vibration, sound and air resonation. The physical vibration of the floor, walls or furniture is created by sound coming from the speaker. In addition, there is physical vibrations that are caused by the cab and these are transferred to the floor. These negative attributes can cause excessive masking/mud/build-ups in the low mids. This is often the issue of bad arrangement or placement, such as the floor. The floor is excited by the vibrations of a sub sitting directly on it. The floor then becomes a resonating surface. It is my 'hopes' that the Roxul tightly compressed inside its housing will absorb sound and physical vibrations transferred through the MDF. Speaking of MDF, it is the most dense building material available. It is very much considered a non-resonant material which is why it is widely used in sound products or sound furniture. I wanted it all wrapped in an additional layer of some sort of sound deadening product. My research resulted in Performix Plasti Dip Rubber Coating. When it comes to sound, the manufacturer claims it is used in conjunction with other materials to provide an absorbing sound barrier. If you search it, car audio enthusiasts use it on their interior and exterior to reduce road noise enhancing their audio. Now for the debate. The legs. I specifically chose the 4x4 Finials because they were pressure treated- dense and hard. I wanted the project/riser raised off the floor. I am hopeful and trusting that my picks of materials will do their work and in the end, little vibration will make its way to the bottom of the legs. I hear ya and agree that if you hold one end of a 2x4 raised the other on the ground, when you hit it with a hammer, the vibrations will resonate and grow as it gets closer to the bottom. I want to dampen the hammer avoiding the vibrations in the first place. I do believe, and forgive me if I don't know the terminology as well as you do, that raising the riser off the floor will benefit the sound and control the wasted speaker energy that travels through floors. The finials are rounded at the top (bottom) and with the weight will imprint nicely into the carpet, which is what I want.

You mentioned a few things- that the batting will not do anything, foam should have been used and again- the legs. I researched both foam and batting. Cheap rigid foam (4x8) will transfer sound. If you are talking about the sound rated 'pillow' or 'couch' foam that would work just as well. Then you have specific Sound Panels which I could not afford. Rather, it seemed absurd to pay for a pack of it for only a few square feet, lol. The batting I used was highly recommended for this specific purpose. You are right, Styrofoam is used for package safety, and effectively so. Corning panels or similar work very well, as you said. But Sound on Sound states foam traps are ok, but you'll get better performance if you build some DIY corner traps using slabs of Rockwool two to four inches thick.

John, I very much researched this before I decided on my build. I have bookmark after bookmark saved so I could reference and re-reference. Again, I don't claim this will work a miracle or even work. But I will settle for a slight improvement. As our house is laid out, its not very conducive for Home Theater. But when I sit in my office, adjoining to living area, and I hear more low bass frequencies than I do in the living room, there is a problem. I think of the lost frequencies in the other room, I think of the wasted energy and negative vibrations... etc. All I want to accomplish is maintaining my bass in the room it is meant and maybe tightening the bass. I am very happy with my Polk 40lb dsw550wi. Now I want to optimize it, maybe, just maybe this will.

Very Best Regards,
Brian

BTW- I think this should be posted in the forums. I appreciated your message and info to me... if you do reply, I look forward to your inputs and maybe corrections to my way of thinking. Keep this in mind, I just started building my AV System a little over a month ago. Although it is modest compared to other systems, I am quite pleased with it. That means I have only been exposed to all this for a few weeks, lol. I think others may learn as much as I hope to if posted.
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Default Re: Riser
3/18/2014
Brian,

I understand the approach you've taken and I definitely don't think you "under thought" it, it is just the mechanism by which that vibration is transmitted IMO. I agree with what you are saying, just not sure if it is going to work as decoupling from the floor more effectively, and I've tried both ways. I found that speaker spikes continued to transmit enough vibration, even when stood on rubber pads, foam, etc...

As a teen (yes, that was a while ago, but yielded some interesting non-scientific results) my dad always had these big, behemoth 12" 3-way horrors in the living room on our hardwood floors and I always thought they sounded horrible (lol at 16 an unprofessed audiophile already). It struck me that part of the problem was them sitting too low and the other was the cabinets being directly coupled to the floor. Without telling dad, I experimented with different things beneath the speakers until I achieved what I felt was an improvement. Interestingly they were just some Sorbothane pads made specifically for this that I found at a high end audio shop - sort of a big square "coaster" that had 8 small raised contact points on them that you set the speaker on, one each corner. Dad didn't notice it IMO, but it opened my eyes to ways of treating speakers to achieve better audio IMO, "tweaking" for lack of a better term. Now the floor no longer vibrated with the speaker and as you've also mentioned, the low midbass improved considerably.

My more recent experience with this phenomenon was a rather large sonotube sub I had. It was a huge down firing 15" beast designed by a friend that shook everything in the house (~1800 sf). Knocking things off shelves in the next room and vibrating doors and windows throughout the house. This was sitting on a concrete slab and always sounded kind of muddy in the midbass to me and I was looking for an improvement. I picked up an Auralex Gramma because I already use MoPads for my mains, and MUCH to my surprise, it cleaned up that midbass as well as reduced much of the vibration elsewhere in the house. I figured with it sitting on concrete it wouldn't have been an issue, but the results said otherwise. I bought it as an experiment and ended up keeping it.

http://i96.photobucket.com/albums/l1...T/IMG_2910.jpg

The new sub is a dual opposed sealed design with a super heavy duty cabinet and it literally does not vibrate at all even with the drivers going crazy. Kind of nice and sounds better than the previous one with music. I tried this sub in the same setup on the Gramma and it sounded no different with or without, so that sort of confirmed to me that the transmission of that vibration is a big part of the culprit of that muddiness. It is the other things in the room/house, etc... exhibiting sympathetic resonances at various frequencies - doors in the room would shake noticeably around 16-18hz, the large panes of glass in the mid to low 20s (which was a problem with many current movies), the adjacent, step up from the slab, wood floor in the high 30s. It was pretty interesting. The Gramma dramatically reduced and/or eliminated many of those issues - then I upgraded to the current sub

As for a riser, some have found that bringing the sub off the floor helps with various room modes, though that depends on the room as well, but that makes sense to me functionally also as sub placement can be quite important. Short of taking measurements in room at various heights though, I think how tall is sort of difficult to pin down.

Wasn't sure how it would come off me questioning your idea, so I didn't want it to degrade into something useless. If you decide to post our conversation in the thread, I have no problem with that. Now I am even more curious to hear your results though

-JG

Hey John, I should have it done by this weekend. Putting 2 coats a day on it then leaving it overnight. Slow process. I am wondering- how can I record the results to see if there is a difference, other than just ear. I thought I could, non-technically, turn off all the other speakers in the configuration menu. I would quiet the whole house, lock the dogs in the garage and leave the sub on and play Super Bon Bon by Soul Couphing. Its a fun song . The song has good hard hitting tight bass as well as a consistent running bass below it. I would play pre and post riser. For others here, I thought I would simply -yes, not very scientific- record it with my phone from 6' straight out and then 12'. I'd stand in front of my French Doors and record it also. Lastly, record it at my foyer entrance. Both pre and post. I'd upload results to my Onedrive and provide a shared folder for anyone who cares to have a listen. Its obvious what my hopes are. I thought the doorways would be good to see if I still get the same amount of bleed through.

That would be anecdotal . To be more precise, I thought I would use my SPL meter under the same circumstances. But I wasn't sure if an SPL meter would be useful in this case and accomplish all the variables? I am looking forward to playing with it.

 

[j_garcia]

I think one would need to do sweeps to detect real changes audio wise for something like this, but it will be interesting to hear your impressions.

 

[BriDown]

Update on Speaker Stand Risers... now I will be able to fully hear them, lol. Will be done by Friday... they sure do soak up the paint!

 

[Jeff R.]

I do not understand how you are decoupling the speaker from the floor.....am I missing something?? Are you going to set the speaker on a layer of foam on top of the stand?

 

[BriDown]

Your question is answered in the various posts between John and I . What we mostly disagree about is the function of the legs. He believes, if I get it correct, that using the legs is a mistake... that it would be better to sit the 'box' on the floor. I disagree and have read the arguments both ways. Although he is probably right, I believe and have read supporting arguments that a platform, such as this, if sat on the floor would create a dynamic relationship. The overall weight of the sub and riser (mine) is not heavy enough to prevent the vibration between the base and the floor. I read a great article that talked about the dynamics and behaviors of a subwoofer using spikes. The sub speaker pushes the sound out and as a result, the force back / feedback of the speaker is lifted in the front as Newton's law suggests creating unwanted vibrations and resonance. His answer to correct this was to securely couple the speaker to the floor with the use of permanent spikes and to add weight to the top of the sub, such as a piece of granite, marble.... etc. Many of you have extremely heavy subs, so I doubt this occurs to you. However, I dont want to do this, I want to decouple because of my bare basement below and 3/4 inch plywood floor. A subs nightmare in my opinion. I have tried to construct my riser to have several degrees of protection. My take on the legs are this- when you have a flat platform, lets say the size of a SubDude II 18-22-1.75, again if there is not enough weight on top- it will be dynamic and travel. The SubDude would sit on my carpet, a heavy weave, but a flexible and moving one. There is not enough to it to heavily sink into my carpet and compress it. I do not believe the SudDude- which is simply 3/4 MDF covered with Velour sitting on a 1" Platfoam Base does as much as it claims. Again, their are ample arguments to and for. I believe my legs will solve the problem of the soft base. 4 legs will carry a greater bearing load than a rectangle platform- which is what I want. Here it is two fold- I want the weight heavy enough to indent my carpet keeping it from being Dynamic but not too heavy that it will completely depress the padding below- the padding will act as another dampener. That is how I hope to decouple it from the floor. I want the Hole (Performix, MDF, r-15 rockwool) to work against vibration and resonance before the legs have a chance to feel it. I am probably being amateur in thinking so, but that is my aim. I think I should mention something I havent before- my sub is downfiring with it's port on the bottom. I really eat into my subfloor causing all kinds of havoc .

I have also read that by doing this, I will more than likely have to increase the volume of the Sub, that is cool. I'll let Audyssey decide this .

Regards,
Brian

 

[BriDown]

Alright, was reading more and u guys got me thinking. Should I use spikes on the bottom of the feet to 'ground' them? The finial feet are rounded, so the full weight would lay on the Spikes. Here is a pair I was looking at - Spikes.

Their claims:
• Dramatically improves clarity, stereo imaging, and bass response
• Great results when used with subwoofer systems
• Solid brass construction with attractive plated finish
• Two-piece tip design for level adjustment
• Barbed inserts can be mounted from inside or outside the cabinet

I would not use the saucers. Would this help or hurt what I want?

Thanks!

 

[BriDown]

Alright, was reading more and u guys got me thinking. Should I use spikes on the bottom of the feet to 'ground' them? The finial feet are rounded, so the full weight would lay on the Spikes. Here is a pair I was looking at - Spikes.

Their claims:
• Dramatically improves clarity, stereo imaging, and bass response
• Great results when used with subwoofer systems
• Solid brass construction with attractive plated finish
• Two-piece tip design for level adjustment
• Barbed inserts can be mounted from inside or outside the cabinet

I would not use the saucers. Would this help or hurt what I want?

Thanks!

 

[fuzz092888]

I have to agree with John. If the subwoofer is transmitting enough vibration through its cabinet to shake things and cause nearby objects to vibrate, then your riser just isn't going to cut it. MDF does resonate and vibrate. I can guarantee you that it does with enough force. However, if the vibrations coming from the sub are small enough that they aren't transmitted through your riser, then they probably could have been negated using a little sorbothane underneath instead of the riser. Then again, none of these things will prevent vibration caused by room pressurization either.

The other thing you need to take into account is that by raising the sub off the floor you may, depending on your room, be altering how it sounds just by doing so since you're changing the reflection points, nulls, peaks, etc. So take that into account in your listening. As for spikes, those are mainly for carpet and I doubt they'd do anything for your risers.

 

[afterlife2]

I have a subdude and I still get some vibrations with any sub(3) I've used on it, so don't expect magic. It will refine the sound nicely if slightly. I like a little rumble in my tiny apt.

 

[j_garcia]

There's the vibration transmitted through the cabinet and then there's the bass itself. You can't really stop things that vibrate from the bass and room pressurization as fuzz stated.

 

[BriDown]

Thanks All, even though you are dirty rotten dream-busters! I am discouraged now and nervous about what to expect, if anything. Really thought I had some good ideas and practices going. Well, it is almost done, so I will find out soon enough. My subwoofer sounds good, but it sits directly on the carpet, I mean to the base of the cab... even with its 'feet' on. Its DownFiring and Ported on the bottom. First I thought- that cant be good. Then I thought, if it sounds this good snug against the carpet, then if I free it a little it will sound even better. That's when I got into the whole riser thing and (I thought) researched it and grasped well enough what I read. Then there was all the vibration in other rooms. At this point, I designed it and starting building.

Then 'You's' ruined my dreams .

 

[afterlife2]

Don't take it like that. Try it you might like what you hear. I made one from a sub styrofoam and carpet and it works pretty nice. I wish I had wood skills and a bigger place like you and the others around here. I'd be building stuff every freakin' day. I'm awaiting your pics when you're done.

Edit here's an old pic from 2 years ago and the first one I made for my first setup:

 

[BriDown]

Will do. I still plan on trying to do some type of pre and post that I can post here... should have it installed late Saturday or more than likely Sunday.


Can always use it as a plant stand!

 

[j_garcia]

I'll reserve any further comment on the concept until you've actually tried it out. I am sure it will help in some way, so let's just see how it goes

 

[BriDown]

They're all done. Here are pics... will start playing and tinkering around with the Sub Box a little later. Will post my results.