Speaker Placement?

[shinerman]

I'm in the process of remodeling the garage for a dedicated listening/ tv sports watching room. (85% music 15% tv sports). The room is about 30' x 18' 5" with a ceiling height of 8' 4". So would like to place speakers for the optimal music listening position. I will be using Khorns and Belles for music(using other klipsch speakers for tv listening). So my question is ............. should I place the khorns on the long or short wall? Any and all suggestions would be appreciated.

[bhendrix]

Try them both ways to see which sounds best in your room. In my room, the K's sound better on the long wall. Room is 24 long by 17'6" wide.

[DrWho]

If you go with the long wall, the sweet spot will be 15 feet back (so 3.5 feet from the rear wall). If you go with the short wall, you're looking at 9 feet back (21 feet from the rear wall)

Are you looking to entertain guests in this room? How big is your display going to be? What will the seating arrangement be?

Generally speaking, the khorns usually sound their best on the long wall, but being 3.5 feet from the rear wall puts you at a boundary cancellation around 80Hz, which is fairly important in most music. The long wall should yield more even coverage across the seats on a couch though. If you ran 3-channel stereo, you would be able to get away with moving the listening position forward a bit.

The short wall is nice in this case because there's a lot of space behind the listening position. You'll be sitting at a 1/3 room dimension point which tends to be a bit more tame with the modal distribution (usually, not always). The only downside is that you'll be so close to the front wall - easilly making a large display rather obnoxious. It does, however, allow the option for another row of seating behind the front couch. The sound field will be very narrow though - not exactly the most exciting thing for either music or sports. You'll probably be a bit too close for the sound from all the drivers to meld together too.

I think trying both ways and listening for yourself is going to be the best plan of attack. If you're creative about it, you'll only need to move one speaker to do the comparison - probably won't even need to move the equipment rack either.

[shinerman]

Some entertaining will be done, but mostly for myself. Flat screen between 48" but no larger than 52". Would be using a couch. If I used the short wall, like you said, it would give me an option of adding another row of seats. My inital thought was the same (trying both ways) and see what sounds best. If I used the short wall, what kind of sound treatment would be necessary for this room size?

[DrWho]

Are you willing to measure the acoustics of your room? If not, there are some guiding principals, but it's really best if you measure. Once measured, it just becomes a matter of interpreting the data and finding the treatment that will do what you need.

[shinerman]

Dr. Who,

I would be willing to do this once the project is complete. Where or who would I contact to get what I would need to measure the acoustics in a room?

[DrWho]

Well there are plenty of threads in this section of the forum talking about it. If you can't find them I can hunt them down and provide some links.

If you have a laptop handy, you could put together a measurement rig for under $200. I suppose there is always the option of hiring out professionals too...I believe Mark (mas) is in Texas so you might consider hitting him up for some help, or he might know of some people in the area too. How nice of me to volunteer Mark's time []

Another option would be to "rent" the rig I've put together. It basically consists of a laptop, mixer, mic, and audio interface all pre-wired and calibrated.

The basic concept behind acoustical measurement is to obtain an accurate representation of the room's impulse response. Once obtained, you can pretty much see everything that's going on - at the location of the microphone. Knowing the dimensions of the room and the relative position of the mic in the room, you can pretty much calculate where the acoustical treatment needs to go. Or if you had fancy software it would tell you (and even shine a laser).

I know describing it like this is a bit cryptic, but it's pretty cool once you see the measurements. I hope I haven't talked to much - I'm no expert, but I think I can point you in the right direction. If not, I'll go hunt down Mark []

Man...I really shouldn't be on a laptop at work - here's a word from a fellow employee:

'l;,l,l,p,plk

Man, 5 bands on a Thurday night is crazy hectic...rock on.

[Roc Rinaldi]

Did somebody say "Roc on?"

[colterphoto1]

Dr. Who,

I would be willing to do this once the project is complete. Where or who would I contact to get what I would need to measure the acoustics in a room?

what's the point of measuring once the project is done?

measure the acoustics BEFORE so you know what to do. Listen to Doc and MAS, they won't steer you wrong.

[Roc Rinaldi]

Dr. Who,

I would be willing to do this once the project is complete. Where or who would I contact to get what I would need to measure the acoustics in a room?

what's the point of measuring once the project is done?

measure the acoustics BEFORE so you know what to do. Listen to Doc and MAS, they won't steer you wrong.

Intentionally.

[mas]

Dr. Who,

I would be willing to do this once the project is complete. Where or who would I contact to get what I would need to measure the acoustics in a room?

what's the point of measuring once the project is done?

measure the acoustics BEFORE so you know what to do. Listen to Doc and MAS, they won't steer you wrong.

Intentionally.

Well, that's not entirely true...

Depending upon how much trouble someone is, we have no problem watching (or actively contributing to) someone run in circles chasing their tails. Besides, there is a uncannily perverse sense of delight one receives in knowing that one has contributed to such entertainment.

[][6]

[Roc Rinaldi]

Do da, do da, dey.

[Roc Rinaldi]

Dr. Who,

I would be willing to do this once the project is complete. Where or who would I contact to get what I would need to measure the acoustics in a room?

what's the point of measuring once the project is done?

measure the acoustics BEFORE so you know what to do. Listen to Doc and MAS, they won't steer you wrong.

Intentionally.

Well, that's not entirely true...

Depending upon how much trouble someone is, we have no problem watching (or actively contributing to) someone run in circles chasing their tails. Besides, there is a uncannily perverse sense of delight one receives in knowing that one has contributed to such entertainment.

[][6]

See Mark this is how you get in trouble sometimes. You know, like getting my newly started thread on "Forum Awards" shut down in milliseconds !!! That hurt.

[shinerman]

I think it would be kinda pointless to take measurments in a half sheet rocked room................

[mas]

I think it would be kinda pointless to take measurments in a half sheet rocked room................

Of what kind of room would it make sense to take measurements?

Measurements tell you exactly with what you are dealing and identify the specific artifacts to be addressed. And they also provide feedback to indicate if the adjustments made actually corrected the precise anomaly you wish to treat, instead of simply moving a problem around.

Simply put, first you deal with the LF below 300Hz by measuring the standing waves/room modes and damp them. This addresses the room peaks and nulls and boominess of the bass. Treatment is in the form of tuned traps, primarily Helmholtz resonators of various types usually applied in and near the corners and possibly the intersections of adjoining plane surfaces (walls/floor/ceiling).

The measurements are also invaluable in helping you to know when to STOP! ESPECIALLY with the surgical application of absorption, which is ONLY applied surgically to remove early arriving first order reflections in order to establish a suitable ISD (initial signal delay) gap in which the direct sound is experienced anechoically for a small time interval.

Perhaps the most common problem created by the user is in overly applying absorption resulting in a room that is far too 'dead'. (And the easiest way to do this is to damp the high frequencies which are not a problem! And these low energy high frequencies are the only component of the room's sound field that may come close to having a truly statistical diffuse character. So the most common action often taken by many is to hurt the one facet that is correct in the room!)

You WANT the finite energy to remain 'in' the room. But as this remaining energy is in the form of audible focused 'specular' reflections, the goal then becomes to diffuse the focused specular reflections into a more diffuse semi-reverberant field that decays (in gain) in a well behaved exponential manner providing a sense of space - making the small room appear to be larger.

But, to address your question more directly...I am assuming that you refer to your room in this manner as you think it has deficiencies. And in what environment are measurements more valuable? In a room with perfect acoustics? Or in a room where additional knowledge of the characteristics and deficiencies would allow one to take meaningful and appropriate remedial action? To beat the proverbial horse, I would suggest that the worse the room response is, the more you will benefit from measurements!

Oh, and Roc. Some folks need to learn to read for meaning and to recognize the overall tone and not impose their feelings on the intentions of a post. Like the post above. If anyone interpreted that in ANY form other than wry wit meant to elicit a grin, they have some serious problems.

And if responding to an intentionally inflammatory remark specifically directed at others by simply acknowledging it as such is a problem, I might suggest that perhaps the initial source of the problem should be considered as the problem, and not simply the acknowledgment of such.

Wouldn't it be a nice change if folks choose to discuss ideas instead of worrying about trying to evaluate others about whom they know little or nothing?

[shinerman]

Only two walls of the room have been sheet rocked, still have two walls left and the ceiling. No flooring has been laid (still concrete). So I should be taking measurements in the room even though the consturction phase of the room is not complete?

[colterphoto1]

Assuming that your room dimensions are fixed, I was talking about measurement for acoustical contols to be put into place after sheetrock and furniture installation. Just for tweaks before the room is considered 'finished'.

[Roc Rinaldi]

Michael,

Since when did you become a "house?"

...and can you select an avitar that we can look at for more than one or two seconds at a time?

Thanks,

Your adoring Forum fans.

[DrWho]

It actually might not be a bad idea to measure right now - but it's going to be more important to measure when the room is closer to its final acoustic behavior (ie, all the walls put up).

It's probably too late to suggest this idea, but if you've still got walls that need to go up, then you might consider splaying them. Anytime you can move away from parallel surfaces is always a good thing.

But as far as measurements...you should be able to get an idea of the low frequency issues that you're going to be facing. Knowing ahead of time the problem frequencies might allow you to integrate some acoustical solutions into the walls before you finish them up. Specifically I'm thinking about Helmholtz Resonators inbetween the studs. Your room is rather large so I imagine that there's going to be quite a bit of other stuff going into the room. I don't know what all you have in mind, but I'm sure there's gotta be a few things that you could turn into an acoustical advantage. It becomes very difficult to make these decisions without knowing where the problems lie.

The only thing is that acoustical treatment is generally considered ugly. To make it look good after the room is finished is much more expensive than integrating it into the design of the room. The only problem with the latter is the degree of forethought required in making solutions before you know what the problems are...almost makes you wonder why somebody doesn't sit down and try to create an ideal room and sell it...

Anyways, there's a lot of cool things one can do, but there's a lot of subjectivity in the approaches (both aesthetically and acoustically).

Btw, I totally dig that portrait Mike....did you snap that picture yourself?

[shinerman]

Dr Who,

Thanks for your suggestions, I do appreciate it. Helmholtz Resonators inbetween the studs? How would one do this?