Ron's Speaker, Turntable, Power and Room Treatment Upgrades

[audioguy]

Thank you for performing this analysis!

I rounded up those listed dimensions, and the wall design will apply another haircut.

The actual, interior dimensions will be about 19’ wide, 24’ long and 14’ high. The rear third of each of the left side wall and the right side wall are completely open to other rooms.

Does that change your analysis?

Then my analysis means nothing. That simulator assumes sealed rectangular rooms.

My guess, then, is that you may end up with a lot more flexibly in finding a reasonable solution. But, if you are not close minded about it, some kind of sub EQ still may still be a way to both fine tune your sub performance and assist in the subs/main integration. While I am sure some on this forum will disagree strongly with me, sub EQ is less pernicious (to my ears - zero negative impact) than doing the same in other areas of the frequency spectrum. Even doing an A2D followed by a D2A conversion within the sub EQ box is inaudible (assuming you don't use some noisy cheap piece of crap EQ device).

Lots of choice for such devices. Three that pop into mind are QSC, miniDSP and Xilica. You may be fortunate and not need such a device but the only way you will know is once your room is complete and your speakers are in place. Then, with some measuring software (OmniMic can be up and running in 5 minutes and is incredibly intuitive and easy to use and cost $300 or REW, which is more complex but close to free - you need a calibrate mic which you can aquaria for about $70.00) and moving the listening chair and subwoofer columns (furniture sliders from Home Depot will prove invaluable) , you can see what you end up with. It can be a long and interative process but, in my opinion and personal experience, it is the only way you will end up with the very best, most optimal performance. When I had my 550 pound Dunlavy SC-VI's, I could push those monsters around with one had using 6 of those sliders.

Looking forward to your efforts in this area.

 

[Ron Resnick]

Thank you for the revised view! (That is a relief.)

Thank you for the suggestion, but I am closed-minded about sub-EQ. Even if I were not I would not run the full-range signal going into and coming out of the bass towers through any ADC.

 

[marty]

Thank you for performing this analysis!

I rounded up those listed dimensions, and the wall design will apply another haircut.

The actual, interior dimensions will be about 19’ wide, 24’ long and 14’ high. The rear third of each of the left side wall and the right side wall are completely open to other rooms.

Does that change your analysis?

Ron,
By the amroc calculator
https://amcoustics.com/tools/amroc?l=24&w=19&h=14&ft=true&r60=0.6
you seem to be in pretty good shape (easily in the Bolt-area) for a good room ratio with reasonably well distributed modes (assuming a closed room. not sure how the openings will effect this)
Marty

 

[Ron Resnick]

Thank you very much for performing this very interesting analysis, Marty! I appreciate it!

(I am hoping that the open spaces in the rear third of the room might release some excess low frequency pressure, and I will have the ability to keep them open or to cover them with acoustic drapes.)

 

[Ron Resnick]

Bonnie's current thinking on the wall treatment, from inside the wall to the visible exterior surface of the wall, is . . .

For the wood framed sections: wood framing filled with blue jeans insulation and then 5/8" of Hardiebacker and thin-set adhesive (the .42" Hardiebacker with the adhesive thin-set becomes about 5/8") and then 1" "firred-out" wood blocks and strips filled with two 1/2" layers of SoundSense Acoustic Thermal Insulation and then 5/32" of NoiseOut2 (vinyl) and then drywall.

For the cinder block sections: 5/8" drywall then 1" "firred-out" filled wood blocks and strips filled with two 1/2" layers of SoundSense Acoustic Thermal Insulation and then 5/32" of NoiseOut2 (vinyl) and then drywall.

Bonnie proposed the outer layer should be plywood, rather than drywall, but DDK is adamant that plywood does not sound good, so I vetoed the plywood in favor of drywall.

 

[Folsom]

I love DDKs advise but...

Wood is the most even in absorption and deflection of basically anything besides safety glass. However, it could be right so as in maybe the better choice is solid wood opposed to laminated (tongue and groove euro style perhaps, instead of plywood) - confirming what DDK says in a way.

Mike has all wood, and it's not any kind of a problem. He likes a little really high frequency dampening but that may have nothing to do with your preference, Ron, especially with drastically different speaker types.

 

[Ron Resnick]

David does not object to hardwood like Mike has (Baltic Birch, I think), but only to generic plywood, I think.

 

[microstrip]

(...) Bonnie proposed the outer layer should be plywood, rather than drywall, but DDK is adamant that plywood does not sound good, so I vetoed the plywood in favor of drywall.

Bonnie is an acoustician who is designing your room and you go against her decisions? Plywood is an extremely well studied acoustic material https://asa.scitation.org/doi/abs/10.1121/1.1906370 and I would suppose she is using it to fine tune your room.

Can I ask what is the technical or acoustic problem with birch plywood?

 

[PeterA]

Bonnie is an acoustician who is designing your room and you go against her decisions? Plywood is an extremely well studied acoustic material https://asa.scitation.org/doi/abs/10.1121/1.1906370 and I would suppose she is using it to fine tune your room.

Can I ask what is the technical or acoustic problem with birch plywood?

Considering the size of David's speakers, isn't the front wall of his room basically flat and curved plywood? What did Bonnie say when you vetoed the use of plywood? Did she describe how it might affect the sound?

 

[Mike Lavigne]

Considering the size of David's speakers, isn't the front wall of his room basically flat and curved plywood? What did Bonnie say when you vetoed the use of plywood? Did she describe how it might affect the sound?

my 2 cents is that not all plywood is created equal. and throwing generalities at wall materials without consideration of structure and finish texture is just wrong.

1/4" or 1/2" ply is different than 3/4" ply. and 2 layers of 3/4" ply is another level, are the seams overlapped? is it a finish grade or rough on the outside. and how stout is the wall structure? is the plywood screwed and glued? how many screws? is it Quietrock 458 with double layer of 3/4" plywood on top? heavy load bearing wall? is it the speaker end of the room? the ceiling? or the rear of the room? are full media shelves over the top of it? how much bass energy is involved? vintage subs down to 30hz? or big boy sub towers down to 3hz?

then you have room size and ceiling height.

you just cannot throw out true-isms.

be prepared to tune to taste.

btw; the only Baltic Birch ply I have are my speakers; which are a few thousand layers of it. otherwise it is relatively generic finish grade 3/4" plywood; with multiple screwed and glued layers in many places, and cabinetry on top of the plywood in other spots.

 

[microstrip]

my 2 cents is that not all plywood is created equal. and throwing generalities at wall materials without consideration of structure and finish texture is just wrong.

1/4" or 1/2" ply is different than 3/4" ply. and 2 layers of 3/4" ply is another level, are the seams overlapped? is it a finish grade or rough on the outside. and how stout is the wall structure? is the plywood screwed and glued? how many screws? is it Quietrock 458 with double layer of 3/4" plywood on top? heavy load bearing wall? is it the speaker end of the room? the ceiling? or the rear of the room? are full media shelves over the top of it? how much bass energy is involved? vintage subs down to 30hz? or big boy sub towers down to 3hz?

then you have room size and ceiling height.

you just cannot throw out true-isms.

be prepared to tune to taste.

(...)

All very good points. It is why the abstract of the article I referred states "Effects of thickness of the (birch) plywood, of the air space back of the panels, and of absorbent backing were investigated, as well as that of damping material applied to the plywood."

 

[ddk]

Considering the size of David's speakers, isn't the front wall of his room basically flat and curved plywood? What did Bonnie say when you vetoed the use of plywood? Did she describe how it might affect the sound?

My baffles are veneered hardwood not plywood Peter.
david

 

[ddk]

I have experimented with various plywoods of differing thicknesses and veneers including baltic birch and find it too absorptive, that quality might be what you want in a speaker cabinet but not the room. You can get both mass and a very even balanced sound from sheetrock and insulation sandwich and then fine tune it with a hardwood panels for a richer, more natural sound. My taste goes towards a livelier room than a dead one, IME plywood has a very distinct sonic signature you'll find people with plywood for front walls slowly overtime and maybe even subconsciously change their listening setup from far field to near field to avoid hearing that coloration.

david

 

[microstrip]

My baffles are veneered hardwood not plywood Peter. I have experimented with various plywoods of differing thicknesses and veneers including baltic birch and find it too absorptive, that quality might be what you want in a speaker cabinet but not the room. You can get both mass and a very even balanced sound from sheetrock and insulation sandwich and then fine tune it with a hardwood panels for a richer, more natural sound. My taste goes towards a livelier room than a dead one, IME plywood has a very distinct sonic signature you'll find people with plywood for front walls slowly overtime and maybe even subconsciously change their listening setup from far field to near field to avoid hearing that coloration specially when one has very dynamic speakers.

david

Plywood has higher absorption than sheetrock or hardwood, but we should remember that Ron speakers are dipoles with 100% back radiation. When using the Soundlab's I have to partially absorb the back radiation, but for the XLF's I need a more reflective front wall. I also prefer livelier rooms - IMHO most listening rooms are too absorptive.

 

[ddk]

Plywood has higher absorption than sheetrock or hardwood, but we should remember that Ron speakers are dipoles with 100% back radiation. When using the Soundlab's I have to partially absorb the back radiation, but for the XLF's I need a more reflective front wall. I also prefer livelier rooms - IMHO most listening rooms are too absorptive.

I know nothing about his speakers but it’s easy to apply controlled absorption or diffusion later if needed, fighting a damp dead room is mostly a losing battle unless it’s a very large space, then everything changes again.

 

[PeterA]

David, Thanks for sharing more details about your speakers' construction material and the generalized statement that Ron attributed to you about avoiding plywood. Are you speaker baffles hardwood veneer over plywood, or hardwood veneer over something else?

I am interested in learning why Bonnie made the recommendation to Ron in the first place. He did not specify what type of plywood she recommended, whether it was softwood or hardwood ply, the thickness, or hardwood veneered over other wood or ply substructure. If Ron vetoed the plywood in preference to sheetrock final finish layer, then did Bonnie change the substructure sandwich materials before the finished sheetrock layer. It is a fascinating issue which most of us don't even consider because we simply move into a finished room and add surface treatment if necessary.

Ron has an interesting project which now has over 100 pages of discussion.

 

[ddk]

David, Thanks for sharing more details about your speakers' construction material and the generalized statement that Ron attributed to you about avoiding plywood. Are you speaker baffles hardwood veneer over plywood, or hardwood veneer over something else?

Veneer over solid wood no plywood in the baffle but the side walls of the bass horn are probably made with some kind of plywood but I can't tell.

I am interested in learning why Bonnie made the recommendation to Ron in the first place. He did not specify what type of plywood she recommended, whether it was softwood or hardwood ply, the thickness, or hardwood veneered over other wood or ply substructure. If Ron vetoed the plywood in preference to sheetrock final finish layer, then did Bonnie change the substructure sandwich materials before the finished sheetrock layer. It is a fascinating issue which most of us don't even consider because we simply move into a finished room and add surface treatment if necessary.

Ron has an interesting project which now has over 100 pages of discussion.

This isn't an exact science Peter, knowing the room dimension we can all run basic calculations to see if there'll be any major problems and fix the dimensions if possible and take basic precautions with the HVAC, wiring, furniture, etc. but the rest of it is guess work based on experience knowing that there have to be some adjustments once the room is built. This isn't a dedicated ground up construction that you can spec everything from scratch, I'm aiming for a particular type of overall sound and quality that I can work with when making recommendations, probably Bonnie's doing the same based on her own targets and approach.

david

 

[microstrip]

(...) This isn't a dedicated ground up construction that you can spec everything from scratch, I'm aiming for a particular type of overall sound and quality that I can work with when making recommendations, probably Bonnie's doing the same based on her own targets and approach.

david

It is exactly why I think that picking and mixing suggestions from both sides is somewhat strange... Let us hope Ron tell us more details.

 

[Ron Resnick]

Bonnie is an acoustician who is designing your room and you go against her decisions? . . .

Dear Francisco, my "world view" about decision-making (whether is the corporate world, the governmental world or the audio world) is that advisors make recommendations and decision-makers make the decisions.

As fas as I know Baltic Birch plywood is an excellent and very robust and dimensionally-stable material.

Bonnie has not yet specified a particular type of plywood. At the moment I think she is thinking just garden-variety 1/4" to 1/2" plywood.

Bonnie specifically said there are different ways to achieve the same, or a very similar, acoustic outcome. She said there is no definitively "correct" solution which renders all other designs incorrect or invalid.

If David has a particular objection to the "sound" of garden-variety plywood, and I can use another material to the same or similar acoustic effect, then I am open to solving for conflicting recommendations with a single, multilaterally-agreeable solution.

 

[microstrip]

Dear Francisco, my "world view" about decision-making (whether is the corporate world, the governmental world or the audio world) is that advisors make recommendations and decision-makers make the decisions.

As fas as I know Baltic Birch plywood is an excellent and very robust and dimensionally-stable material.

Bonnie has not yet specified a particular type of plywood. At the moment I think she is thinking just garden-variety 1/4" to 1/2" plywood.

Bonnie specifically said there are different ways to achieve the same, or a very similar, acoustic outcome. She said there is no definitively "correct" solution which renders all other designs incorrect or invalid.

If David has a particular objection to the "sound" of garden-variety plywood, and I can use another material to the same or similar acoustic effect, then I am open to solving for conflicting recommendations with a single, multilaterally-agreeable solution.

Thanks for the clarification. Perhaps wrongly I considered that no one would use garden variety materials in a serious listening project.
I think that if you look at the published absorption data of the materials being considered you will understand my point. Also IMHO great designers also bring their empirical knowledge to listening rooms and fiddling with their choices is a risky exercise - there are no definitively "correct" solutions, but there are some definitely "incorrect" solutions. BTW Floyd Toole addressed this issue in his book - how a small hidden detail can ruin the whole room acoustics.