New room demensions??

Artemis · « **on:** 19 Jan 2010, 04:40 pm »

Hello, I'm new to this site so this is my first post.Acoustics seems to be a little more important on this site then some other's I have visited..I always say no matter what equipement you have it's not going to sound the best without a good room!My question is what are good room demensions?I'm building a new 2 channel listening room from scratch.I know there are companys(Rives) that specialize in this service but i'm a DIY guy.I'm looking for the perfect demension's for a LARGER audio room to compliment full range speakers.My current room is 14 x 22 with 7 1/2' ceiligs .I'm open to all suggestions on this subject.Any help would be great..

TRADERXFAN · « **Reply #1 on:** 19 Jan 2010, 04:44 pm »

How large is large? You capitalized it... so are you talking massive?

See part 2 on this page for some info on ideal room ratios and a calculator.
(The stiffness of the walls and #/size of openings will cause variance)

http://www.ethanwiner.com/acoustics.html

-Tony

rollo · « **Reply #2 on:** 19 Jan 2010, 05:00 pm »

For a start before the Gurus provide comments try using the Cardas golden ratio. Contact the speaker manf. as well and ask what size room would be ideal for their use.

charles

Artemis · « **Reply #3 on:** 19 Jan 2010, 05:13 pm »

I was thinking about a size around 18 or so wide by 25 long but can be a little bigger.My speakers are no longer being made but I have talked to the company at one time and the owner said the ideal listening distance was at least 12 ' away from the speakers..The reviews on the speakers also suggested this distance..I always like to form a triangle from the speaker's distance apart and the same to the listening seat.This set up always sounds best to my ears

TRADERXFAN · « **Reply #4 on:** 19 Jan 2010, 05:24 pm »

How tall of a space? Sounds like you have a nice sized room.

Which speaker? Any sub?

Tony

Artemis · « **Reply #5 on:** 19 Jan 2010, 05:41 pm »

I was thinking around 9 or 10 foot ceilings but not sure if that makes sense.everything right now is up in the air for this project.My speakers a Artemis EOS/sig with large bass module.

jimdgoulding · « **Reply #6 on:** 19 Jan 2010, 05:51 pm »

I posted this in a discussion over at Audio Asylum yesterday. The general info is applicable, I think. My triangle is like 56" but my room is a bunch smaller than yours. My speakers are MTM standmounts and play a lot larger in my 12x14x8' room than a person might think that this placement could allow . .

Thanks, David. My seat is normally somewhat further away, also. Funny thing about imaging, sitting at the apex of equilateral the whole presention will recede and expand out behind the speakers as described above. Moving my seat back a foot is rather like moving back a few rows in a hall tho with images gaining density and roundness. As I listen from a chair rather than a sofa, I can and do sometimes move my seat depending on the recording. If guys are willing and can play with this I think they will see what I mean. The sensation of a stage and sometimes instruments themselves will be outside of the speaker position the nearer I sit. As I move further back, images seem to gain in palpability and dynamic life tho too far and I lose some of that volume and breadth of field. And toe-in can matter to this. I listen with front firing radiators and sometimes wonder what the effect would be using more omni-directional speakers.

If I had my druthers, I would have larger speakers in a larger room but would maintain my distances only extrapolated out. At least for starters, I would.

Artemis · « **Reply #7 on:** 19 Jan 2010, 06:07 pm »

The speakers sound good in my current room but not great.I heard these speakers in a bigger room and they were incredible.Right know theres a issue with the lows .These speakes go down pretty low and my current room is not allowing this unless I move way back,as I go back theres no mid's and then the imaging goes away but the bass is better.Up closer the speakers disapear but the lower bass is real thin...I tried moving the speakers in different positions with the same end result..

Artemis · « **Reply #8 on:** 20 Jan 2010, 11:27 pm »

Is there anybody who built a new sundroom from scratch?..I'm looking at whats the best approach to take on this project..

Scottdazzle · « **Reply #9 on:** 20 Jan 2010, 11:36 pm »

The golden ratio would get you something like 26 x 10 x 16 (if you can manage a 10' ceiling). I wish I had a room about that size. Avoid 17'6", the wavelength for 60 Hz.

Nyal Mellor · « **Reply #10 on:** 21 Jan 2010, 12:01 am »

First off I would advise buying, borrowing, lending or stealing your self a copy of Floyd Toole's Sound Reproduction book.

Dimensions are only one of the factors in getting your room to sound good. Someone with the right measurement tools and knowledge can work their way around a lot of room related issues.

And just because you've got a golden ratio room doesn't mean there isn't going to be room modes, reflections and other normal things going on.

Basically you need to avoid having dimensions that are multiples of each other, as these cause room mode reinforcement. Try searching online for room mode calculators and have a read up on the Bonello criterion. Also for your speakers you'll want to factor in space behind you and space behind the speakers plus the distance you need between yourself and the speakers. Room dimensions should come naturally from that

TRADERXFAN · « **Reply #11 on:** 21 Jan 2010, 12:50 am »

I already gave the guy a room mode calculator (well, directed him to Ethan's!)

poseidonsvoice · « **Reply #12 on:** 21 Jan 2010, 01:09 am »

Quote from: Nyal Mellor on 21 Jan 2010, 12:01 am

First off I would advise buying, borrowing, lending or stealing your self a copy of Floyd Toole's Sound Reproduction book.

Dimensions are only one of the factors in getting your room to sound good. Someone with the right measurement tools and knowledge can work their way around a lot of room related issues.

And just because you've got a golden ratio room doesn't mean there isn't going to be room modes, reflections and other normal things going on.

Basically you need to avoid having dimensions that are multiples of each other, as these cause room mode reinforcement. Try searching online for room mode calculators and have a read up on the Bonello criterion. Also for your speakers you'll want to factor in space behind you and space behind the speakers plus the distance you need between yourself and the speakers. Room dimensions should come naturally from that

+1.

Absolutely and positively agree. Remember, Cardas' "Golden" Ratios minimizes certain room modes slightly but it doesn't eliminate them at all. Much of these 'golden' ratios never took into consideration where a loudspeaker may be placed in a room and also where the LISTENER might be as well. If the listener is closer to a corner, suddenly the modes that are of consideration when the listener was in the middle of the room, completely change with regards to which modes are accentuated. In other words, it changes depending on position of the loudspeaker and listener or listeners and thus there are multiple different permutations. One cannot predict them all. But one can minimize them.

You want to do it the right way? After you've selected the dimensions of your room (and it can be "Golden" if you like(!)), the MOST important aspect is its construction. If you can have double studded walls with fiberglass in between, etc...as Toole and Geddes explains, that will take you very far compared to all other fancy rooms out there that seem to give more attention to interior decoration than anything else. You can have your cake and eat it too.

Anand.

TRADERXFAN · « **Reply #13 on:** 21 Jan 2010, 04:57 am »

One key point. There will always be room modes... you are just attempting to avoid having them lump together by applying these ratios. Due to variance in structure materials and precision, you will not be able to actually predict them for a specific seating position, or loudspeaker\listening position combination. So don't get too obsessed.

The approach advocated by Geddes is to use constrained layer damping with non hardening adhesive (like green glue, certain liquid nails products, etc) between double drywall, to create low frequency absorption. Isolate the rooms exterior with floating decoupling techniques to lower ambient noise. Then use controlled directivity loudspeakers and multiple subs to create his ideal soundfield.
No other room treatments required, except maybe some diffusion.

If this interests you, you should check out his book. There are some chapters posted free here
http://www.gedlee.com/Home_theatre.htm

Ordering it, you would get to see the rest of the book which discusses some approaches, and even some unconventional techniques to achieve this. So its worth it.

Tony

K Shep · « **Reply #14 on:** 21 Jan 2010, 05:25 am »

Quote from: Nyal Mellor on 21 Jan 2010, 12:01 am

First off I would advise buying, borrowing, lending or stealing your self a copy of Floyd Toole's Sound Reproduction book.

Or just go here and order one:

http://www.amazon.com/Sound-Reproduction-Acoustics-Psychoacoustics-Loudspeakers/dp/0240520092/ref=sr_1_1?ie=UTF8&s=books&qid=1264051449&sr=1-1

A must have for every audio enthusiast.

Artemis · « **Reply #15 on:** 22 Jan 2010, 02:59 am »

Thanks for the comments.I wan't to do this once and done.I've made some bad choices buying audio in the years and cannot afford to do this again.This room is going to be a new basement area with the floor and the walls being pured concrete to start..then framed inside..

jimdgoulding · « **Reply #16 on:** 22 Jan 2010, 06:15 am »

That's what Mike in Colorado has done, same as you're planning, and his room looks very good to me. I can't remember Mike's moniker but some of you guys looking in here may. Hope you will put these guys together.

lonewolfny42 · « **Reply #17 on:** 22 Jan 2010, 06:36 am »

Quote from: jimdgoulding on 22 Jan 2010, 06:15 am

That's what Mike in Colorado has done, same as you're planning, and his room looks very good to me. I can't remember Mike's moniker but some of you guys looking in here may. Hope you will put these guys together.

mgalusha...

FullRangeMan · « **Reply #18 on:** 22 Jan 2010, 10:33 am »

HI Artemis,
I also suggest you the Golden Ratio(1,00 x 1,618 x 2,618) or 10 ft hi, 16,18 ft wide and 26,18 ft deep.
I think you can not go wrong with Golden Ratio, because it is a classic size room, very used in Churchs and too on B&W UK research Center in this same sizes above.
This Golden Ratio proportions are the dimensions of the Ark of the Covenant that the Lord gave to Moses in the Bible, so this is a very special room.
Of course you can increase the room sizes since you keep the same Golden proportions.
Good Luck.

Nyal Mellor · « **Reply #19 on:** 22 Jan 2010, 06:58 pm »

Traderxfan is spot on

First dimensions but don't sweat it too much as a lot depends on listener and speaker position.

Second construction, don't be tempted to go for the concrete bunker, use sheetrock walls which flex to absorb low frequencies

Third acoustic treatment

Fourth calibration / voicing