Designing a 6.1 system around a living room - building stage (1 Viewer)

[Javier_Huerta]

Hi,

I'm currently in the process of building my new home, and while it has a dedicated HT, I'd also like to take advantage of DVD-A and DTS Audio on my living room.

I'll soon post pictures of my living room. It's trapezoidal in shape, with one of the walls made of stone and the rest of them made of bricks, with vaulted ceilings decorated with oven-heated bricks (the closest style I could say it is, is modern-mexican).

Anyway, I was thinking about installing my MartinLogan system there, too, so I am currently thinking about hiding my 6.1 system either on the corners of the roof, or built into the walls.

The speakers I'll use are Definitive Technology ProMonitor 80's all around. The subs will be a pair of Definitive Technology ProSub100's.

I have a couple of questions, though...

+ Mexican construction techniques are very different to US' ones. So myy house has concrete pillars, brick walls all around and stone (earthquake proof, I hope). Any changes I make to the walls have to be made now in order to run the cables through conducts throughout the walls.

+ So I am wondering, if I wall-mount my DefTechs (using the included baffle, of course) will I hurt their sound quality much? I know there's a tonal change from mounting them flush with the walls, but I don't know exactly how much would it be.

+ Would I be better off by installing them in the corners of my roof and aiming them at the seating area? They wouldn't look that integrated, but if I can get away with some extra fidelity, I'm all for it.

TIA

Javier.

 

[Travis G]

Hi Javier,

Are your Def Techs Bipolar speakers? In other words are there speakers on the back of the enclosures? If so the bipole radaition will be mostly lost (a good thing IMHO).
Also since your speakers are designed to be placed out from the walls, putting the speakers in the walls will make them sound too bass heavy. This is especially noticable with male voices and will cause them to sound too full.

With subwoofers on the other hand, there may be a benifit to putting them inside the walls (providing that you do not block the vents on ported subwoofers.) Putting subwoofers near the rooms boundaries, especially when they are placed in the corners, exites all room resonances more equally. Sometimes this is a bad thing depending on your rooms acoustics. The best thing to do is try different locations and see where the subwoofer sounds the best. Play some jazz or electronic music with alot of bass and listen to see if certian notes sound too loud and others are more subdued. Where ever you hear the smoothest tonal quality is the best place to put the subwoofer.

A trick that saves alot of time is to put the subwoofer at the listening position and crawl around your room listening for the smoothest response.

I hope this helps.

Travis

 

[Drew Eckhardt]

Anyway, I was thinking about installing my MartinLogan system there, too, so I am currently thinking about
hiding my 6.1 system either on the corners of the roof, or built into the walls

Yes, you will hurt the sound quality. Placeing full-range speakers (as opposed to sub-woofers) near walls is bad. Placement near the ceiling at a corner near three walls is even worse.

The problems are :
1) You're changing the frequency at which baffle step occurs, which doesn't mesh with the compensation. In theory, you could compensate for this with equalization though.

2) You're shortening the interval between when the direct sound reaches you and when the reflected sound reaches you so that the reflections will be perceived as the original sound thus resulting in a loss of clarity.

If you must hide the speakers, place them normally and build a false wall out of acoustically transparent fabric (grill gloth, Guilford of Main FR701, etc). Or buy high-quality inwall speakers. Or settle for Bose quality

OTOH, sub woofers are fine in corners. In fact, that's where you'll usually get the most uniform respone, and you'll also get more volume than if they were placed elsewhere.

 

[Javier_Huerta]

Travis, my DefTechs are the smallest model, and are not bipolar. They are quite unobtrusive and I love their sonic signature, much more than the sound of their bigger or bipolar models.

Drew, thanks for your comments about placing speakers near the corners. I'd assume in a small speaker such as the ProMonitor 80 a little bass boost would actually be beneficial, and I have the option of mounting them far away from the corners, too. The subs will be built inside some cabinets, hidden from view.

I still haven't decided whether the Martin-Logans will share the space of the DefTech ensemble. I feel such speaker will be at risk when a party is going on in the living room. Maybe I'll put them in the studio... dunno yet.

 

[Travis G]

Javier,

You know the value of visually discrete video speakers. I think it's important for the speakers to dissapear when the lights are turned down low and the movie starts. If your speakers fail here than they will be distracting, and won't provide a good illusion.

But that aside, If your speakers are designed to be placed out from the walls then the baffle step has already been compensated for in the crossover network design. If you put them in the walls the lower frequencies will be 3-6dB too high. If they are placed against the wall (but not inside), you will get a smeared stereo image as well as audible frequency response anomolies.

If you are using a subwoofer, and assuming your def techs have a reasonably low frequency extension and power handling there is no reason that you should need to boost the bass anymore.

I like Drews false wall idea. Infact, I have been planning on making screens out of grill cloth to hide my speakers behind for awhile.

Good luck

Travis