In-wall rear surround recommendations

[mossman77]

Did you do any experimenting with both ports open, eq 2? You don't have to recalibrate anything, just open 'em up and let 'r rip. Make sure you switch to eq 2 with both ports open tho. EQ 1 with both open will actually void the warranty if something goes wrong.

I hadn't considered doing that. I figured it would only make the decay time worse. I suppose it would allow me to turn down the gain even more and get things even cleaner?

 

[Pogre]

I hadn't considered doing that. I figured it would only make the decay time worse. I suppose it would allow me to turn down the gain even more and get things even cleaner?

Just try it without touching the gain. If you turn it down it kinda defeats the purpose of removing the ports and switching to eq 2. When I first got my Hsus I thought I preferred 1 port, eq 1 because of that little extra extension. I thought there could be a little more pop tho and was advised to try 2 open ports, eq 2 so I did and I gotta say, I prefer the extra output in the audible range over the deeper extension which is largely inaudible (and often not even present!).

Look, don't get too focused on the charts. This is something I could advise for myself as well. I know how easy it is to get wrapped up in those sweeps. I'll bet you're sounding pretty damned good now. When you try the setting I suggest, listen first and do not measure first! Give it a chance. Listen to a variety of music before you bust out the mic and see how you like it.

 

[mossman77]

Just try it without touching the gain. If you turn it down it kinda defeats the purpose of removing the ports and switching to eq 2. When I first got my Hsus I thought I preferred 1 port, eq 1 because of that little extra extension. I thought there could be a little more pop tho and was advised to try 2 open ports, eq 2 so I did and I gotta say, I prefer the extra output in the audible range over the deeper extension which is largely inaudible (and often not even present!).

Look, don't get too focused on the charts. This is something I could advise for myself as well. I know how easy it is to get wrapped up in those sweeps. I'll bet you're sounding pretty damned good now. When you try the setting I suggest, listen first and do not measure first! Give it a chance. Listen to a variety of music before you bust out the mic and see how you like it.

Yeah, I don't plan on breaking out the mic again at this time. Don't get me wrong, it sounds pretty darn good. I'll give open and try it out. Hold off on the bass traps for now? I figure they can only help. The one corner upstairs where the second sub is located is pretty loud.

 

[ryanosaur]

Bass traps, to be effective, are very large. The cylinder traps, for example are usually 18"+ dia. The other best option are 2' wide panels mounted in the corners, floor to ceiling. Remember, you are talking Soundwaves that are 37' long at 30Hz, and over 56' long at 20Hz.
My recommendation is to not worry about room treatments. At least not for a while.

 

[mossman77]

Bass traps, to be effective, are very large. The cylinder traps, for example are usually 18"+ dia. The other best option are 2' wide panels mounted in the corners, floor to ceiling. Remember, you are talking Soundwaves that are 37' long at 30Hz, and over 56' long at 20Hz.
My recommendation is to not worry about room treatments. At least not for a while.

GIK has corner traps that are only 16"x16". Maybe I would just get two up in the corner where the upstairs sub is, because it is pretty "boomy" there.

 

[mossman77]

Just try it without touching the gain. If you turn it down it kinda defeats the purpose of removing the ports and switching to eq 2. When I first got my Hsus I thought I preferred 1 port, eq 1 because of that little extra extension. I thought there could be a little more pop tho and was advised to try 2 open ports, eq 2 so I did and I gotta say, I prefer the extra output in the audible range over the deeper extension which is largely inaudible (and often not even present!).

Look, don't get too focused on the charts. This is something I could advise for myself as well. I know how easy it is to get wrapped up in those sweeps. I'll bet you're sounding pretty damned good now. When you try the setting I suggest, listen first and do not measure first! Give it a chance. Listen to a variety of music before you bust out the mic and see how you like it.

I've been running the subs with both ports open and I'm liking the sound. Now just fiddling with the Q to maintain the tight bass without losing too much SPL across the band.

 

[Pogre]

I've been running the subs with both ports open and I'm liking the sound. Now just fiddling with the Q to maintain the tight bass without losing too much SPL across the band.

Not bad when you start with a good response, huh? I rolled my sleeves up this weekend and was thinking about you. I made a thread yesterday.

Audyssey MultEQ Editor App- What Am I Doing Wrong?!

@PENG, @ryanosaur, you guys are who I've talked MultEQ with the most, I believe... I'm really getting sick of fighting this thing. When I make a change in the curve editor I click "Done" then "Done" again to save the changes. I open it back up, changes are still there, I upload to my receiver...

forums.audioholics.com

First couple of posts are just me bitching and bragging, lol. A little further down I describe my method to someone who asked about custom curves.

 

[mossman77]

Decided to take a few measurements using tones as opposed to pink noise. Here's what I got with individual tones (SPL equal for both subs when playing pink noise). Given the significant discrepancy at 31.5 Hz and 63 Hz, should I try correcting each sub individually to see what I come up with collectively? Or maybe take the average and decrease the gain of sub2 accordingly? OR play around with different port configurations to get a better balance (e.g. ports open/EQ2 on sub1 and 1 port open/EQ1 on sub 2). Coincidentally, those are my favorite two frequencies
f (Hz) | Sub 1 (dB) | Sub 2 (dB)
31.5, 71.5, 77.3
40, 75.5, 77.8
50, 81, 79.5
63, 77, 60
80, 64, 65

 

[mossman77]

Decided to take a few measurements using tones as opposed to pink noise. Here's what I got with individual tones (SPL equal for both subs when playing pink noise). Given the significant discrepancy at 31.5 Hz and 63 Hz, should I try correcting each sub individually to see what I come up with collectively? Or maybe take the average and decrease the gain of sub2 accordingly? OR play around with different port configurations to get a better balance (e.g. ports open/EQ2 on sub1 and 1 port open/EQ1 on sub 2). Coincidentally, those are my favorite two frequencies
f (Hz) | Sub 1 (dB) | Sub 2 (dB)
31.5, 71.5, 77.3
40, 75.5, 77.8
50, 81, 79.5
63, 77, 60
80, 64, 65

Sorry, I was overthinking things. I want to treat both subs as if they are a single sub. My FR curve looks as good as I could have hoped for and things sound really good. I had to make a couple tweaks after removing both ports (had a dip around 32 Hz), but REW was able to filter it out. Just need to work on getting those low-end decay times down which I'll hopefully be able to achieve by isolating the one sub from the floor and may try adding a corner bass trap up on the balcony since that sub is in a corner with a pretty significant room mode. Don't get me wrong, things sound great as-is, but I've become a little obsessed

 

[Pogre]

Sorry, I was overthinking things. I want to treat both subs as if they are a single sub. My FR curve looks as good as I could have hoped for and things sound really good. I had to make a couple tweaks after removing both ports (had a dip around 32 Hz), but REW was able to filter it out. Just need to work on getting those low-end decay times down which I'll hopefully be able to achieve by isolating the one sub from the floor and may try adding a corner bass trap up on the balcony since that sub is in a corner with a pretty significant room mode. Don't get me wrong, things sound great as-is, but I've become a little obsessed

Well, at least you're not down here alone! Ha ha! Welcome to the funny farm, lol.

Yeah, don't get too jiggered up over the individual measurements. It's how they sum together as a whole during playback that counts. You really do have some great results and you worked for it. I can see you possibly making some incremental improvements, but you're in a really good spot right now and should just relax and enjoy.

I'm gonna share with you what Ed Mullen over at SVS told me when I exhausted just about every configuration I could possibly have in my living room. I've been obsessed with the bass response of my towers without subs in play since I got REW. I have subwoofers tho and with them in play I couldn't ask for much better, yet still here I am... Believe me, I know the struggle. It's real, lol.

Hi Jason -

Thanks for the update!

It sounds like you've done everything possible to minimize the audible impact of that persistent null.

We're all victims of room acoustics to a greater or lesser extent - as nulls go this one isn't horrible.

In the end you'll need to make peace with it - otherwise it will continue to plague you and ruin the enjoyment of your system - something I've sadly seen play out hundreds of times with other REW users.

REW is a double-edged sword and while knowledge is certainly power - we also need to recognize that imperfection exists in all aspects of our lives - so in this case I would call it good and put away the mic.

LMK if I can assist you with anything else - thanks Jason!

Ed Mullen, PE
Director - Technology and Customer Service
SVS | Specialty Technologies
877.626.5623

 

[mossman77]

View attachment 35251

Well, at least you're not down here alone! Ha ha! Welcome to the funny farm, lol.

Yeah, don't get too jiggered up over the individual measurements. It's how they sum together as a whole during playback that counts. You really do have some great results and you worked for it. I can see you possibly making some incremental improvements, but you're in a really good spot right now and should just relax and enjoy.

I'm gonna share with you what Ed Mullen over at SVS told me when I exhausted just about every configuration I could possibly have in my living room. I've been obsessed with the bass response of my towers without subs in play since I got REW. I have subwoofers tho and with them in play I couldn't ask for much better, yet still here I am... Believe me, I know the struggle. It's real, lol.

Hi Jason -

Thanks for the update!

It sounds like you've done everything possible to minimize the audible impact of that persistent null.

We're all victims of room acoustics to a greater or lesser extent - as nulls go this one isn't horrible.

In the end you'll need to make peace with it - otherwise it will continue to plague you and ruin the enjoyment of your system - something I've sadly seen play out hundreds of times with other REW users.

REW is a double-edged sword and while knowledge is certainly power - we also need to recognize that imperfection exists in all aspects of our lives - so in this case I would call it good and put away the mic.

LMK if I can assist you with anything else - thanks Jason!

Ed Mullen, PE
Director - Technology and Customer Service
SVS | Specialty Technologies
877.626.5623

I just realized changing the Master Volume field in REW from L to L+R increases the sub SPL by about 5dB. Crap. Why do they make this an option, and do I use L+R or either one L or R?

 

[mossman77]

I spoke with a guy from GIK and he recommended I first isolate the subs from the floor, then re-assess. Makes sense. His advice was to build a "plinth" for each sub, from wood, filled with sand, and at least equivalent in weight to the sub. I asked about height off the floor and he said that isn't typically an issue.

 

[Pogre]

@ryanosaur hit up some place local to him that does marble work, I think. Iirc he was able to get some nice, heavy scrap pieces cut to his dimensions for not a whole lot of money and is very pleased with the results. I just summoned him so he can give you more details.

 

[mossman77]

@ryanosaur hit up some place local to him that does marble work, I think. Iirc he was able to get some nice, heavy scrap pieces cut to his dimensions for not a whole lot of money and is very pleased with the results. I just summoned him so he can give you more details.

I have a remnant from my kitchen counters I can experiment with first. So stone slab better or just as good as wood box with sand? Stone is lower profile, which I like.

 

[Pogre]

I have a remnant from my kitchen counters I can experiment with first. So stone slab better or just as good as wood box with sand? Stone is lower profile, which I like.

My house sits on a cement slab so I've never explored decoupling or isolation techniques. I would say stone would be at least as effective as sand, but I have no idea what to suggest for thickness.

 

[ryanosaur]

This place does custom poured concrete, of which I was able to select some scrap countertops that were not suitable for the final job... $50 a piece for them, cut to size, ground smooth, sealed, and drilled out.
I don't think marble is as good... Granite is best. We have a local quarry that I was considering granite... they were gonna charge me about $70 per piece. Their stuff was green... but somebody I spoke to along the way recommended finding Absolute Black Granite... that it might be the best in terms of being acoustically inert.

Maple is a very good wood to use for what you are talking about. It is hard, and naturally absorbs and dampens the acoustic vibrations. Maple cutting boards are easy and relatively inexpensive to acquire, too.

 

[mossman77]

This place does custom poured concrete, of which I was able to select some scrap countertops that were not suitable for the final job... $50 a piece for them, cut to size, ground smooth, sealed, and drilled out.
I don't think marble is as good... Granite is best. We have a local quarry that I was considering granite... they were gonna charge me about $70 per piece. Their stuff was green... but somebody I spoke to along the way recommended finding Absolute Black Granite... that it might be the best in terms of being acoustically inert.

Maple is a very good wood to use for what you are talking about. It is hard, and naturally absorbs and dampens the acoustic vibrations. Maple cutting boards are easy and relatively inexpensive to acquire, too.

What about the weight of the platform? Sounds like heavier is better, in which case stone sounds like the better option. And would I lay it directly on the carpet or put feet underneath? Feet under the sub and feet under the slab doesn't sound like a good idea to me.

And is the idea to isolate the sub enclosure from the floor, or to dampen the energy radiated from the bottom of the sub enclosure from interacting with the floor?

 

[ryanosaur]

What about the weight of the platform? Sounds like heavier is better, in which case stone sounds like the better option. And would I lay it directly on the carpet or put feet underneath? Feet under the sub and feet under the slab doesn't sound like a good idea to me.

And is the idea to isolate the sub enclosure from the floor, or to dampen the energy radiated from the bottom of the sub enclosure from interacting with the floor?

It's not about weight... its about damping ability. Some stone slabs will ring like a bell. Some concrete, too. Some wood is very resonant.
I posted that video of a guy making a sand-filled box for an amp stand...
There were links to some posts where you can see what I did for my own Speakers and Subs, too...

In-wall rear surround recommendations

Should have mentioned the previous curves are with both ports plugged. I'd like a little deeper extension, so I'm going to remove one port plug for now and redo everything. Also, I'm getting some localization at higher volumes because the damn floor is vibrating. I was thinking of giving the...

forums.audioholics.com

 

[mossman77]

It's not about weight... its about damping ability. Some stone slabs will ring like a bell. Some concrete, too. Some wood is very resonant.
I posted that video of a guy making a sand-filled box for an amp stand...
There were links to some posts where you can see what I did for my own Speakers and Subs, too...

In-wall rear surround recommendations

Should have mentioned the previous curves are with both ports plugged. I'd like a little deeper extension, so I'm going to remove one port plug for now and redo everything. Also, I'm getting some localization at higher volumes because the damn floor is vibrating. I was thinking of giving the...

forums.audioholics.com

Okay. Maybe they mentioned making the plinth as heavy as the sub because otherwise there wouldn't be enough sand to provide good isolation. The scrap piece of quartz I have is pretty damn heavy, so evidently very dense. Haven't had a chance to try it out yet. Would placing the sub directly on the slab (with some sort of vibration isolation between them (e.g. Dynamat) and feet between the slab and floor make more sense that slab on floor and feet between sub and slab?

 

[ryanosaur]

Okay. Maybe they mentioned making the plinth as heavy as the sub because otherwise there wouldn't be enough sand to provide good isolation. The scrap piece of quartz I have is pretty damn heavy, so evidently very dense. Haven't had a chance to try it out yet. Would placing the sub directly on the slab (with some sort of vibration isolation between them (e.g. Dynamat) and feet between the slab and floor make more sense that slab on floor and feet between sub and slab?

My understanding of quartz, is that IT IS A RESONANT MATERIAL.

Weight is NOT a measure of dampening ability.

As I said above:

It's not about weight... its about damping ability. Some stone slabs will ring like a bell. Some concrete, too. Some wood is very resonant.

That wasn't just me typing for the sake of typing.