Standalone Audio Room

[Grateful]

If I were building a room from scratch these would be my target dimensions!

Hi Ron,

Thank you, very much, I greatly appreciate your input and confirmation!

Best regards,
Jeffrey

 

[Grateful]

Jeffrey,

my comments about the ceiling were not about a slope, although that can work. it's just about having something not just flat and bare. take a look at the link at the bottom of my post, and observe the shape of my ceiling. a flat painted sheetrock ceiling will have a severe influence negatively on the sound. especially in a large room at high energy with speakers moving lots of air.

some driver types do reduce that issue.

there are many ways to deal with the ceiling. you just have to realize all the reflective surface that is there and have a plan. and since you have a clean sheet of paper you don't have to try and solve a problem after the fact. you can get ahead of it.

Hi Mike,

Thank you, very much! My wife recommends using a cast iron skillet but the key is merely repeating your true point until I finally get it.

My current room has a decent ceiling to accomplish this goal. There’s about a 12” border which is about 6” lower than the center. Rives had me put soffits in three borders and angled absorption boards (wood with insulation on top) in the center.

Best regards,
Jeffrey

 

[DasguteOhr]

Today, there are some really great acoustic materials that discreetly provide excellent sound. For example, there's acoustic plaster that, when simply applied to a wall or ceiling, has a broadband effect of 200 Hz - 20 kHz.

Akustikputz von UPECO - Permanente Schalldämmung

Schaffen Sie eine angenehme Raumakustik mit dem Akustikputz von UPECO. Die hervorragenden Absorptionswerte bieten die ideale Lösung für alle Räumlichkeiten.

www.upeco.at

Once the room is finished, I would conduct a measurement to find the problem area in the bass range. In that area, I would only combat the room modes; too much sounds bad. Ideally, use plate resonators Have the exact size calculated and then have it built
Exsample

GIK Acoustics Sound Block Oben - 60x60cm Konfigurator | Audiosteps

Bassfalle und Absorber Optional mit FlexRange Technologie Optional mit Diffusor-Platte Stapelbar mit Schiebe- und Verriegelungssystem

www.audiosteps.io

 

[Grateful]

35' x 25' does great things, but finding intimacy in a room that big and being able to give the bass some leverage will be a challenge. so make sure you are willing to pony up to measure up to the challenge. many speakers will sound lost. most speakers are designed to have some room reinforcement.

those really nice mid powered tube amps will run out of steam unless you have 110db efficient speakers.

Hi Mike,

Excellent point, much thanks! I can’t swing a seven digit system. Better stated, I’ll probably get hit with the cast iron skillet, when my wife refuses to stop swinging it, after I buy a seven digit system.

Best regards,
Jeffrey

 

[Grateful]

Today, there are some really great acoustic materials that discreetly provide excellent sound. For example, there's acoustic plaster that, when simply applied to a wall or ceiling, has a broadband effect of 200 Hz - 20 kHz.

Akustikputz von UPECO - Permanente Schalldämmung

Schaffen Sie eine angenehme Raumakustik mit dem Akustikputz von UPECO. Die hervorragenden Absorptionswerte bieten die ideale Lösung für alle Räumlichkeiten.

www.upeco.at

Once the room is finished, I would conduct a measurement to find the problem area in the bass range. In that area, I would only combat the room modes; too much sounds bad. Ideally, use plate resonators Have the exact size calculated and then have it built
Exsample

GIK Acoustics Sound Block Oben - 60x60cm Konfigurator | Audiosteps

Bassfalle und Absorber Optional mit FlexRange Technologie Optional mit Diffusor-Platte Stapelbar mit Schiebe- und Verriegelungssystem

www.audiosteps.io

Hi,

Very interesting! Thank you, very much, I’m completely ignorant about currently available acoustic materials! Clearly, I have a LOT to learn!

Best regards,
Jeffrey

 

[Grateful]

While non-parallel surfaces (wall-to-floor; side wall-to-side wall; front wall-to-back wall) is a good idea from a reflectivity perspective, I do wonder if this doesn't create a seemingly infinite number of closely-spaced primary room modes. Maybe this creates a more uniform frequency response as a result?

One school of thought is that shoebox-shaped (rectangular) rooms have a more predictable influence on the sound one hears and thus, placement of speakers and listening position and any low-frequency room treatments can be better tailored.

Hi Young Skywalker,

Have you discussed this with Yoda? I’d love to hear his feedback.

Best regards,
Jeffrey

 

[DasguteOhr]

Hi,

Very interesting! Thank you, very much, I’m completely ignorant about currently available acoustic materials! Clearly, I have a LOT to learn!

My pleasure, the thickness of how it's applied determines the RT60 time . For example, I applied 27mm thick, contour-wise at 0.45-0.5 milliseconds. It still sounds lively, not as dry as a recording studio with 0.25 without reverberation.
example photo structure of the walls applied by hand two colous grey& cappuccino.

 

[Kingrex]

View attachment 154977

Mike,
Are your corner cavities stuffed with something or just lined around the interior edges. Doesn't the void and lining have a frequency dependent damping affect. No idea what frequency that would be. But it seems it would absorb something.

 

[Grateful]

Consider sound leakage to and from the outside in determining if you wish to isolate the listening room, and be aware a conventional HVAC with blowers and such can be noisy. The additional cost to add heavy floating walls is probably not huge for new construction so I'd just do it rather than wonder later. I would use a minisplit that puts the noisy part outside the room, and you could build a small attached sub-shed for it for protection and further noise reduction.

I wouldn't bother doing anything with the floor other than flooring (pad and carpet would be my choice). You can easily float the walls and ceiling during construction for isolation (and it is almost impossible to do later). Track lights minimize holes in the walls that can bleed sound, and the usual technique for outlets and in-wall lighting is to seal the back (they make fabric or composite covers for the backs of outlet boxes), pack the boxes with insulation, and caulk (acoustic caulk if you wish but normal caulk is usually OK) the edges around the boxes to minimize sound leakage. A heavy solid exterior door with full weather sealing will help reduce noise through the door and is much cheaper than a purpose-built studio door. Make it wider than usual for those speakers and listening couches, plus just makes it easier to haul gear in and out.

I would specify 200 A or better service just to get larger wiring, and 20-A outlets everywhere. Several of my outlets have the lower AC outlet tied to a switch near the door so I can scatter a floor lamp or two around rather than putting lights in the ceiling or on the walls (fewer holes, fewer things to rattle).

You could consider a secondary room as part of the build that serves as storage for boxes, manuals, spare cables, and all the other "stuff" that accumulates. Most minsplits are dual so you could install a second heat/cooling unit in the storage area independent of the main listening room.

For room treatment, I prefer a fairly "dead"" room, but have somewhat of a studio background so it's my preference. I usually suggest adding absorption or diffusion at first reflection points on the side walls and ceiling, same behind the listening position if the rear wall is fairly close, then living with it a while before going any further. That usually means a couple of side panels, another couple suspended from the ceiling, and maybe two to four behind the listener(s).

FWIWFM - Don

Hi Don,

Thank you, very much, for your extremely helpful and informative reply! Many great ideas and insights!

Best regards,
Jeffrey

 

[Grateful]

35' x 25' does great things, but finding intimacy in a room that big and being able to give the bass some leverage will be a challenge. so make sure you are willing to pony up to measure up to the challenge. many speakers will sound lost. most speakers are designed to have some room reinforcement.

those really nice mid powered tube amps will run out of steam unless you have 110db efficient speakers.

Hi Mike,

Very roughly, how much more would I need to pony up (gear wise) for a 35’ x 25’ x 14’ versus your 29’ x 21’ x 11' room?

Much thanks,
Jeffrey

 

[sbnx]

Hi Todd,

Thank you, very much, for your assistance!

Thanks, I can make 35’ x 25’ x 14’ happen! I could build a 50’ x 25’ x 14’ stand alone structure. Should I slope the interior ceiling as Mike mentioned?

Best regards,
Jeffrey

No need to slope the ceiling. What Mike has (and what I have) is a large soffit that goes around the perimeter of the ceiling. It makes a huge bass trap that is out of the way and adds architectural interest to the room. I suggest making a "shoebox" shape. This is very predicatble. If you start slanting walls and doing things of this nature then it will be dificult to predict what will happen once the room is built.

As someone pointed out, a room of this size will require a lot of speaker to drive it. I would suggest a high efficiency speaker. in a room that size I would not considre anything less than 92 dB 1Watt-1 meter. (Not the 2.83V thing) Of course horns would work well. But also Goebel if you are looking for a "box" speaker. The Stenhiem Ultime 2 is also efficient. You are likely going to need a very good pair of large subwoofers to get the low bass and really drive the room.

 

[Mike Lavigne]

Hi Mike,

Excellent point, much thanks! I can’t swing a seven digit system. Better stated, I’ll probably get hit with the cast iron skillet, when my wife refuses to stop swinging it, after I buy a seven digit system.

i've been married 51 years so i get it. hifi visitors are always telling my wife that 'Mike is so lucky to have such a supporting wife'. my wife's reaction is to smile and say that 'don't confuse support for understanding'. that always gets a chuckle. but it's the most we can hope for. that our wives/partners do understand that this hifi obsession is good for us. she might never see the value of hifi itself. if any of us have a wife that seriously shares the hifi hobby itself all the better. but that is rare. marital relationships are all different and so the dynamics are personal....and may involve an iron skillet.

Hi Mike,

Very roughly, how much more would I need to pony up (gear wise) for a 35’ x 25’ x 14’ versus your 29’ x 21’ x 11' room?

i think it's more the effort involved in really finding musical bliss in such a huge room, than purely a dollar issue. although that does enter into it. at the end of the day, a checkbook does not get you to the finish line. but it's part of it. big systems that are spendy can be just plunked down in a huge room and we can talk ourselves into being happy with what we see.

the idea of what it takes to harness a huge room such as 35' x 25' x 14' starts with what music do you really like, and do you expect your musical tastes to evolve to, or in what direction. are you chasing large orchestral or rock show level reproduction with large scale? and do you like to listen at higher SPL's? to fill a room like that and pressurize the bass so it hooks up is going to take higher SPL's. are you an all day listener lots of times? or an hour or two here and there? it's nice to have a system where the music can be immersive and intimate at lower volumes. which takes a room to be 'right size'.......which can be a wide variety of sizes but past a certain size that's hard.

maybe the easiest way to consider this is at an audio show. we see systems in oversized rooms trying to make it work. mostly they don't work as well as our home systems in more real world rooms.

Todd suggested some speaker systems that can handle large rooms. and what sort of amplification do you like? do you already have an 'end game' target for amps and speakers? what size rooms do they work best in?

so i can only ask questions mostly.

i know in my case i could have had 35' x 25' x 14' in my barn if i would have eliminated the hallways. but i felt like that would be too big and unwieldy. the only reason i would have considered that would be if i wanted huge Genesis dipoles that require rear wall reflectivity. i liked those huge monsters, but never loved them. everything sounds big, whether that serves the music or not. which was not my deal.

follow the music and what it takes to connect the best with your style and tastes.

i feel that my big but not huge 21' x 29' x 11' room can pull off any scale of music i like. it does WARP 11 when called on. i listen to lots of large orchestral. yet get's very intimate and immersive with girl with guitar too. it's a reach out and touch it presentation. and i listen 4-6 hours a day year round. it works at 65db-80db normal listening volumes with presence and energy just great and still connects too. it did take me a decade of work to be able to exceed that intimacy compared to my previous smallish 12' x 18' x 10.5' room.

so whatever size room you have will take work to get it all the way there.

 

[Mike Lavigne]

Mike,
Are your corner cavities stuffed with something or just lined around the interior edges. Doesn't the void and lining have a frequency dependent damping affect. No idea what frequency that would be. But it seems it would absorb something.

in my front corners there are no bass traps per se. but there are 12" x 30" (they are wider at the rear as the wall angles) floor to ceiling cavities (enclosed in 3/4" finish grade ply) for the cold air returns. the opening to the cavity is 12" x 20". they more break up the corner than any predictable bass trapping. but would guess there is an effect going on from the air return opening.


if you look at my picture of the room plan, you can see 4 bass traps, one on either side of my rear wall Lp shelving. these are 12" x 16" but they are 11 feet tall. so they are quite large. they are lined with (as i recall) 701 fiberglass. these were not spendy to have built in, but trying to add these later would have been impossible.

 

[MarkusBarkus]

...the fact that those corner cavities are open to the room (to some extent) as cold air returns probably helps mitigate any boom effect.

I have such a box (~2'x4') which hides a supporting lolly-post which had quite a boom-box effect. Blowing in cellulose and adding external fabric/fiberglass panels took care of the effect. Just a data point FYI for the discussion, gents.

 

[Mike Lavigne]

...the fact that those corner cavities are open to the room (to some extent) as cold air returns probably helps mitigate any boom effect.

I have such a box (~2'x4') which hides a supporting lolly-post which had quite a boom-box effect. Blowing in cellulose and adding external fabric/fiberglass panels took care of the effect. Just a data point FYI for the discussion, gents.

those cold air returns were inside my front bass traps until 2010 when i removed the bass traps and had the cold air returns enclosed inside Quietrock 545 and the 3/4" Finish Grade Plywood. here is a pic from before the room was finished.

 

[Mike Lavigne]

here are pics of the build process for the rear bass traps. before and after.