DIY Subwoofer Risers

[Slec]

Classic!

[Fors*]

Originally Posted by Big Daddy

This is the difference between men and women. This picture shows the recation of a man or a woman when you ask them:

"Let's go have a drink".

Attachment 5749

As usual Big Daddy, you are a wealth of knowledge.....LOL!

[aramis109]

Got my Auralex Gramma in. Have yet to try it out (will here shortly) but the fit and finish of it is very nice. It's very sturdy and adds about 3" of height to the sub as well as decoupling. There's absolutely no way this is going to rattle the floor now- the foam is really thick.

Overall I'm pleased in the build. I'll update on how well it works here in a bit.

[Aerodude73]

Originally Posted by aramis109

Got my Auralex Gramma in. Have yet to try it out (will here shortly) but the fit and finish of it is very nice. It's very sturdy and adds about 3" of height to the sub as well as decoupling. There's absolutely no way this is going to rattle the floor now- the foam is really thick.

Overall I'm pleased in the build. I'll update on how well it works here in a bit.

be sure to post pics!

[aramis109]

Yeah I'm behind on pics overall. I watched The Spirit (ugh, bad movie). So far, I'm not sure how I feel about it. It definitely removes the boominess but it also kinda feels like I have less bass overall. Definitely need to listen more and see if its just something I need to get used to.

[liquidice]

that's exactly how I felt about what I built (GRAMPA), but then I started to adjust, and mess around with settings, and re-calibration, and it just ended up sounding awesome! It is a difference from movies I watch repeatedly. You definately need to at least run the receiver calibration over again, and then maybe tweak the sub gain up just a little afterwards. That's all I did, and I'm happy. Don't have an SPL meter to test yet. Soon enough. Oh, and stuffing helped a lot too.

[jomari]

theres a significant difference due to how 'cleaner' it would reproduce sound. its not always about the thump, but about how clean it sounds comparitively. again, subjective to taste, to judgement, to well, our ears.

if ever liquid you do purchase a spl meter,
1. list down all the settings youve had on your current room settings,
(volume of testing, distance, details indicated by your audessey program),

2. then list or print out BD's guide on using a SPL meter, take good notes, and indicate each and every change you will make. consider another column, heck hide the first one if you'd like... and see how it goes in comparison to what you had.

this is part of the learning experience. most of us prefer to listen to our systems kinda hot, personally, im also guilty of this with my center speaker. (i run mine 4db higher), just because i like it that way.

[JJ]

See, I do the same thing. SPL or not, I do run my L and R surrounds 1.0 dB higher, and my center 1.0 dB higher as well.

[liquidice]

trust me jomari, I will post my reads. I simply trust Audesssy to get me my distance reads, and by using the ole' tape measure, they have come up accurate. EQ on the other hand is something I've always questioned through Audessy.

[JJ]

Well, I got lazy. Just ordered the SubDude HD, and an extension cord for my Dynamo so I can toy with its positioning more. I feel like I'm not unleashing it yet. I'm going to make some sort of riser to put the Dynamo on, and then put those two on the SubDude. We'll see what happens here.

[LoveHomeTheatre]

This may be a dumb question but I'm actually quite interested in the subwoofer riser idea. I would like to build my own but just in case, would I get any benefit from my system. I don't have a real sub woofer but I would like to get rid of the rattling and clanging of glassware and cabinet doors. Its kind of annoying and parents worry something might break eventually. Would these risers help?

[Fors*]

Originally Posted by LoveHomeTheatre

This may be a dumb question but I'm actually quite interested in the subwoofer riser idea. I would like to build my own but just in case, would I get any benefit from my system. I don't have a real sub woofer but I would like to get rid of the rattling and clanging of glassware and cabinet doors. Its kind of annoying and parents worry something might break eventually. Would these risers help?

It should, but only if you use the right material (if you are thinking of building your own). That would include some kind of rubber isolators as feet. Anytime you take a sub or even your fronts (I assume you have these and you are relying on these for your LFE?) off the floor and create seperation, you should get minimal vibration, if any, and this should help your problem. You will also produce a "cleaner" sound, getting some improvement from the quality of your audio that your system provides.

Gentlemen and fellow audio members, did I miss anything?

[liquidice]

well, I'm not 100% on this, but the vibration between the sub and the floor will be reduced. I never really had this problem because of carpteting. Now when the sub is raised, true you don't get that overly 'boomy' bass sound, it is more accurate and punchy. BUT, bass is still bass. The lower frequencies don't go away, they just get better. One thing I haven't done yet is done the sweep test on my AVIA calibration disc. The bass sweep is designed to test the x-over smoothness of a main transitioning to the LFE, but is also used to see what rattles in your house when it gets to the really low frequencies. The only problem I used to have was between 30 -20hz, some rocks in a dish with candles would start shaking. I'll have to see if that still happens. Mr. "LOVESHOMETHEATER", why don't you see if you can just make something temporary to test out in your situation. Maybe just take a small/short table and lay a rug over it. Are you married or have girlfriend?...maybe if she exercises she would have these plastic steps used in alot of workouts. I found those to work pretty well just for test purposes.

[Fors*]

Originally Posted by liquidice

well, I'm not 100% on this, but the vibration between the sub and the floor will be reduced. I never really had this problem because of carpteting. Now when the sub is raised, true you don't get that overly 'boomy' bass sound, it is more accurate and punchy. BUT, bass is still bass. The lower frequencies don't go away, they just get better. One thing I haven't done yet is done the sweep test on my AVIA calibration disc. The bass sweep is designed to test the x-over smoothness of a main transitioning to the LFE, but is also used to see what rattles in your house when it gets to the really low frequencies. The only problem I used to have was between 30 -20hz, some rocks in a dish with candles would start shaking. I'll have to see if that still happens. Mr. "LOVESHOMETHEATER", why don't you see if you can just make something temporary to test out in your situation. Maybe just take a small/short table and lay a rug over it. Are you married or have girlfriend?...maybe if she exercises she would have these plastic steps used in alot of workouts. I found those to work pretty well just for test purposes.

Hey Ice, he says he doesn't have a "real subwoofer" so I'm not so sure what is causing the problem....his fronts?

[aramis109]

Originally Posted by jomari

theres a significant difference due to how 'cleaner' it would reproduce sound. its not always about the thump, but about how clean it sounds comparitively. again, subjective to taste, to judgement, to well, our ears.

if ever liquid you do purchase a spl meter,
1. list down all the settings youve had on your current room settings,
(volume of testing, distance, details indicated by your audessey program),

2. then list or print out BD's guide on using a SPL meter, take good notes, and indicate each and every change you will make. consider another column, heck hide the first one if you'd like... and see how it goes in comparison to what you had.

this is part of the learning experience. most of us prefer to listen to our systems kinda hot, personally, im also guilty of this with my center speaker. (i run mine 4db higher), just because i like it that way.

Yeah, I figured this was it. I assume it takes some getting used to just like when I swapped out my little 8" crappy sub for my current one. I popped in Transformers for the old Ironhide flip scene and all of the bass was there. I know I need to re-run Audyssey but that's something that takes awhile and has to be done when no one is home, so it has to wait.

In the meantime I did break out my SPL meter. Now, when I run the test tones through the sub, I still have my SPL meter set at 80, slow response and C weighting. When I do that, I see fluctuations at my seating point from 74-77db. I assume this is because I have some standing waves/some other type of issue? Either way it basically read the same with and without the riser. Should I perhaps be setting the SPL to a lower setting? I tried them and it was never a stable number.

[liquidice]

Originally Posted by forsberg21

Hey Ice, he says he doesn't have a "real subwoofer" so I'm not so sure what is causing the problem....his fronts?

ahhhh, I should have looked at his signature, good ole Bose Lifestyle V30 system, hence: bass module. So considering the speakers are all the size of my hand, there is no way they could create any low frequencies at all, so any rattling has to be coming from the "bass module". I would still experiment with creating a riser to see what results come of it: good or bad. Curious.

[jomari]

Originally Posted by LoveHomeTheatre

This may be a dumb question but I'm actually quite interested in the subwoofer riser idea. I would like to build my own but just in case, would I get any benefit from my system. I don't have a real sub woofer but I would like to get rid of the rattling and clanging of glassware and cabinet doors. Its kind of annoying and parents worry something might break eventually. Would these risers help?

it really depends. you can try these easy fixes,
1. isolate the subwoofer, using either a gramma/grampa build, or a simple decoupler/isolator, or
2. address a better way to insulate the room its in. (if that at all is possible, some people have em in the living room/space)
3. address where the rattlings coming from - glass fixtures, displays et al, sources of where the rattling is coming from.

your room is exciting certain frequencies that your subwoofer is outputting, most rooms ive been in have that happen during the 33-35Hz frequency, with the room interacting/coloring at that point. you can either address the subwoofer by isolating it and/or lowering the volume, reposition or place it away from the rattle area, or address the effects, which would be the glassware.

heck while were at it, we can go further with that and also address the frequency if you want to, isolating the frequency the room starts interacting with, and address it with a parametric equalizer to reduce resonance, a good example would be the behringer feedback destroyer...



partsexpress

Equalizing a room CAN address certain things that a foam bass trap, heck even a fiberglass bass trap cannot address. problem is, this is another can of worms you'd have to study up on. plus the fact that the back panel isnt er... AVR friendly so to speak, using XLR and TRS jacks to begin with.

Aramis, are you using a certain test tone to get such results? what source tho? DVE? AVR built in test tone? at what frequency if ever? remember, each room can also heighten the performance of the subwoofer/speaker reproducing a certain frequency.

[aramis109]

Originally Posted by jomari

Aramis, are you using a certain test tone to get such results? what source tho? DVE? AVR built in test tone? at what frequency if ever? remember, each room can also heighten the performance of the subwoofer/speaker reproducing a certain frequency.

I'm using the AVR test tones- Onkyo 805. I'm not sure what the frequency is- it's pink noise. It's just weird to see it sort of crest with the sub while it's nearly rock stable on the speaker pink noise.

[jomari]

Originally Posted by aramis109

I'm using the AVR test tones- Onkyo 805. I'm not sure what the frequency is- it's pink noise. It's just weird to see it sort of crest with the sub while it's nearly rock stable on the speaker pink noise.

hmm. thats the problem with built in test tones.
1. not having the full bandwidth pink noise to assist in setting up your subwoofer.
***2. edited under wrong assumptions, of course corrected by big daddy. apologies.***
3. cannot choose which frequencies you want to tune in so to speak...

personally, id choose a DVE or Avia Calibration disc. The avia isnt on blu yet, but if im not mistaken, its a bit hot at 85Db...

[aramis109]

Originally Posted by jomari

hmm. thats the problem with built in test tones.
1. not having the full bandwidth pink noise to assist in setting up your subwoofer.
2. most receivers use white noise instead of pink noise.
more detail can be found here...

white vs pink noise

3. cannot choose which frequencies you want to tune in so to speak...

personally, id choose a DVE or Avia Calibration disc. The avia isnt on blu yet, but if im not mistaken, its a bit hot at 85Db...

Ugh, that article went right over my head. Lemme just ask is there a free calibration disc out there that will do better than the receiver test tones? I'm running Audyssey first and then going back and checking and tweaking with the SPL. I have been very pleased with the results overall, but don't want to continue to sink money in to tweaking discs, and SPL's and all of that.


*edit* Wait, I have a DVE on dvd. I guess I never looked since it's been tucked away for forever, but does it have test tones and such on it?