Where to start?

Christof · « **on:** 6 Nov 2006, 01:54 am »

I've got a large room with lots of hard surface area....

The speakers will be on the brick wall (right before the strange chimney bump out you see), firing across the width of the room. The width of the room is 18', length is 40' and ceiling height slopes from 14' at windows to 12' above my head as I took the picture. The windows are about 15' to the left of the left speaker position and the photo is shot about 18' from the right speaker. There is a wall right behind me as I shot the photo.

Where to start with acoustic treatments????

Forgot to mention, I cannot relocate the orientation of the speakers because in the small box that runs along the brick wall I had my electrician run 3 isolated ground 20A circuits terminating just before the chimney.

thx
c.

Duke · « **Reply #1 on:** 6 Nov 2006, 03:17 am »

Wow, nice room!

I'm definitely not a room acoustics expert. Here are my thoughts, in random order:

1. In general I prefer a live rather that dead acoustic space, as a slowly-decaying reverberant field adds richness and livelines to the presentation. Looks like you're off to a good start there.

2. Do you have any slap-echo? If so, a tapestry or two along the back wall might help, or along one of the side walls, depending on where it's coming from. You only have to treat one of each pair of opposing reflective surfaces. A throw rug on the floor to take the edge off the floor bounce might be beneficial too. But don't overdo it - too much absorption will suck the life out of the sound.

3. I don't see sidewall reflections as a problem because their path length delay is long enough that they're unlikely to be detrimental.

4. With a large, fairly reverberant room, the power response of the loudspeakers will play a dominant role in their perceived tonal balance. What kind of speakers do you have? Their power response might end up being a significant issue. If we know the on-axis response and driver sizes and types and ballpark crossover frequencies we can make some educated guesses about the power response. Even better, maybe we can find off-axis frequency response curves somewhere on the internet.

5. Are you looking to optimize for best possible sound right in the center of the sweet spot, or do you want good sound throughout the room (even well off to the side of the speakers)? Obviously we'd like both, but assuming you have to lean one way or the other...

6. I can't begin to make a call on bass traps - I think you'll have to listen first and go from there. With the speakers up against one wall and your listening position up against the other, the bass should be strong. Pull either the listening position or the speakers out from the wall, and bass will decrease.

Best of luck to you, Christof!

Duke

PhilNYC · « **Reply #2 on:** 6 Nov 2006, 04:35 am »

Get a rug with a thick rug-pad, make sure you get at least 3-4 feet behind your speakers, and see how it sounds. I bet you get great sound right off the bat...

Daygloworange · « **Reply #3 on:** 6 Nov 2006, 04:49 am »

Yeah, your room has got great bones to work with. I'd also suggest getting your speakers at least 3' away from the wall. An area rug in between you and the speakers. I'm assuming a sofa in the sweet spot, so I'd say to keep that off the back wall (3-4'). If you can, I'd add some diffusers to the back wall.

Side reflections don't really seem to be too much of an issue in your space, given the width of your room.
The possibilities in this room given the dimensional ratios seem to be very good. You should be able to get a great sound in your space without too much effort. A very enviable space to work with there.

Cheers

bpape · « **Reply #4 on:** 6 Nov 2006, 11:57 am »

Agreed. With that much space, you have some luxuries that most rooms don't have.

I'd definitely agree with a nice rug between you and the speakers.

Keep your seating at least a few feet from the wall behind you.

If at all possible, think about some hangings from the ceiling to break things up a bit. Obviously this would need to be done with aesthetics in mind.

If at all possible, think about some 4" thick panels directly behind the main speakers on the brick wall. Keep them down relatively low. Primary purpose is to deal with SBIR issues.

Bryan

woodsyi · « **Reply #5 on:** 6 Nov 2006, 12:59 pm »

Quote from: Christof on 6 Nov 2006, 01:54 am

What's wrong with the boombox?

Is this your work/studio or domestic/living quarter? In other words, what type of decor are you going for?

Christof · « **Reply #6 on:** 7 Nov 2006, 03:37 am »

Quote from: Duke on 6 Nov 2006, 03:17 am

1. In general I prefer a live rather that dead acoustic space, as a slowly-decaying reverberant field adds richness and livelines to the presentation. Looks like you're off to a good start there.

2. Do you have any slap-echo? If so, a tapestry or two along the back wall might help, or along one of the side walls, depending on where it's coming from. You only have to treat one of each pair of opposing reflective surfaces. A throw rug on the floor to take the edge off the floor bounce might be beneficial too. But don't overdo it - too much absorption will suck the life out of the sound.

3. I don't see sidewall reflections as a problem because their path length delay is long enough that they're unlikely to be detrimental.

4. With a large, fairly reverberant room, the power response of the loudspeakers will play a dominant role in their perceived tonal balance. What kind of speakers do you have? Their power response might end up being a significant issue. If we know the on-axis response and driver sizes and types and ballpark crossover frequencies we can make some educated guesses about the power response. Even better, maybe we can find off-axis frequency response curves somewhere on the internet.

5. Are you looking to optimize for best possible sound right in the center of the sweet spot, or do you want good sound throughout the room (even well off to the side of the speakers)? Obviously we'd like both, but assuming you have to lean one way or the other...

1. I prefer a live room
2. Yes there is some slap echo but a very large curtain will be installed to cover the front wall/windows
4. The new speakers are in the works right now, Rick Craig is doing a design which will be used for HT and hopefully, if all goes right, I will use a pair of SP Tech's new speakers for my 2-ch system
5. I want the sound to be best when seated, this forces me to get off my feet and relax occassionally

Quote from: woodsyi on 6 Nov 2006, 12:59 pm

Quote from: Christof on 6 Nov 2006, 01:54 am

What's wrong with the boombox?
Is this your work/studio or domestic/living quarter? In other words, what type of decor are you going for?

Thats only an air cleaner woodsyi

This space is my work/studio/domestic/living quarters all in one. My furniture is minimalist, Corbusier-Mies type 20th century modern.

lonewolfny42 · « **Reply #7 on:** 7 Nov 2006, 08:37 am »

Nice work so far Christof......(older photo)

It's gonna look really nice when its complete........

woodsyi · « **Reply #8 on:** 7 Nov 2006, 01:37 pm »

You are doing a great job with the room. I wish I had that kind of talent to fix up my place.

For the type of decor and sound you like, I would say use soffit bass traps like Jim (AKA Ribbonspeaker) has in his room, bass trap columns and exposed diffusors that has modern look. SRL makes good ones http://www.srlaudio.com/acoustic_images/SRL%20Diffuser%20Panel%20Description.pdfthat I use and I can vouch for their performance. Ethan also has some coming out that looks very modern. I have every confidence that Real Traps diffusors http://www.realtraps.com/diffusor.htmwould work nicely as with all his other products. I would, however, build diffusors with good natural wood if I had the kind of wherewithall with carpentry like you do. Do some research and you can get quadratic formulars with well depth sequence and size for the diffusors. This could be really good.

MaxCast · « **Reply #9 on:** 7 Nov 2006, 01:46 pm »

I'd set up on the short wall.

Daygloworange · « **Reply #10 on:** 7 Nov 2006, 02:45 pm »

Quote

I'd set up on the short wall.

He has his dedicated 20 amp electrical on the brick wall. Regardless of that, he's got a great ceiling height, no first reflection points on the sides to speak of. He's got the back wall that only goes up partially towards the ceiling, which creates a well. ( probably be able to do some creative treatments in there )

Quote

I would, however, build diffusors with good natural wood if I had the kind of wherewithall with carpentry like you do. Do some research and you can get quadratic formulars with well depth sequence and size for the diffusors. This could be really good.

I totally agree and wanted to suggest that, but wasn't sure about decor and WAF. Being that you mention you have a preference for mid-century modern decor, the quadratic diffusers on the back wall would be a great choice, both acoustically, and visually.

I'd probably add that he could suspend some creatively designed diffusion on the ceiling as well that would be in total character with his design theme and take it up to a serious level of room treatment, comparable to studio control rooms.

He's got that kind of serious potential in that space.

Cheers

woodsyi · « **Reply #11 on:** 7 Nov 2006, 02:59 pm »

Quote from: Daygloworange on 7 Nov 2006, 02:45 pm

I'd probably add that he could suspend some creatively designed diffusion on the ceiling as well that would be in total character with his design theme and take it up to a serious level of room treatment, comparable to studio control rooms.

I always liked those parabolic deflectors at live venues. Those would look really nice in natural wood finish in that room.

bpape · « **Reply #12 on:** 7 Nov 2006, 03:04 pm »

Absolutely. Make them out of good wood and stain them and they'd fit right in a modern decor.

Bryan

MaxCast · « **Reply #13 on:** 7 Nov 2006, 03:25 pm »

I realize what was said about the three lines. I would rather have 9 feet to my left and right vs. 3 feet behind my head. Maybe some real long audiophile power cords held up by those expensive ceramic holders. Better than Romex anyway.

Duke · « **Reply #14 on:** 8 Nov 2006, 01:44 am »

Hi Christof,

Thanks for taking the time to answer my questions.

The speakers by Rick Craig I heard at RMAF a couple of weeks ago were superb.

SP Tech speakers do an exeptionally good job of keeping the radiation pattern uniform, so they will have a smooth power response which imho is a high priority in a room like yours.

I think you're headed in the right direction.

Best of luck with your room and system!

Duke

Christof · « **Reply #15 on:** 8 Nov 2006, 02:02 am »

Quote from: lonewolfny42 on 7 Nov 2006, 08:37 am

Nice work so far Christof......(older photo)

It's gonna look really nice when its complete........

Lonewolfny42...it's been one hell of a long trip, everytime I start to loose steam in this project I just tell myself I am going to have a great listening room one day

. This old building was a YMCA boarding house about 40 years ago and ever since has been a free hotel for bums and birds. The pic below was taken about 1 year ago from the same vantage point as the picture which started this thread. This has by far been the most difficult DIY project I've ever tried and to think now I'm trying to figure out room treatments, I'm on the home stretch!!!!

lonewolfny42 · « **Reply #16 on:** 8 Nov 2006, 02:09 am »

WoW !!!! With that new added photo, I can see how REALLY far you have come. It really needed some work !

In the end, it's gonna be a great space.....

Chris

Christof · « **Reply #17 on:** 8 Nov 2006, 02:27 am »

Everything will need to be DIY since this project has left not much of a budget for audio toys

Is the material from which the diffusors(quadratic) are constructed important? I have a heap of flooring scraps left over from almost every hardwood floor job I do which could be made into diffusors pretty easily. If this scrap will work I will build a few and put them on the wall behind the listening position.

In the picture there is a soffit on the ceiling which contains my HVAC plenum. I can also place treatments on the side of the soffit, which is about 12" high by 40' long. Also, what about above the wall that will be behind the listening area? I have a horizontal surface up there of about 4' deep and 25' long that is out of site.

I really appreciate the ideas
-Christof

Canyoneagle · « **Reply #18 on:** 16 Dec 2006, 01:47 am »

OOOH, lath and plaster. Nasty stuff to demo.
How's your dust mask?

Very nice space, and you've done an amazing job with the transformation.

What about something "dead" like a tapestry at the midpoint between the speakers?

Good luck, and I look forward to hearing about your experiences with this audio journey.

Warmly,
Michael

warnerwh · « **Reply #19 on:** 16 Dec 2006, 01:41 pm »

Let me cheer you on

I know how you feel. I had a similar experience with my rental. My present listening room I also built. It took a couple of months only as I had no demo and only needed two walls.

This is the best sound I've heard and it's in my room. Good room treatment with bass traps are the key. Get or build QUALITY bass traps and room treatments. Thick is good, things like rugs and tapestries can help but aren't nearly as good as real room treatments as they're way too thin.

You'll be so happy when you have your own listening room that sounds AMAZING! It's wonderful. I can go sit in my room and have outstanding sound whenever I want. If you want more help with your room acoustics I will give you good help, just PM me.

If you can do that DIY traps and treatment will seem like child's play.

Please accept a very high compliment. It only gets done a step at a time but does get done. It's probably cost you more than you thought but don't feel bad as that happens to experienced people regularly.

Best wishes on your project. The day gets closer every day where you'll have a great room.