opinions on home theater proposal?

[Gmorris]

A friend has heard several of my diy speaker/electronic endeavors and wants me to help him set up a home theater. It will be in a medium sized room apprx. 8' x 15' x 21' and he's hoping to have seats for 8 to 10 people.

I'm planning on using one 300liter sono-sub with dayton dvc 15" woofers on each side of the screen....probably hidden behind curtains. The mains will either be Zaph's mtm, http://www.zaphaudio.com/audio-speaker16.html , or Jon Marsh's Natalie P, http://www.htguide.com/forum/showthr...light=natalie. Mains will be in sealed configuration.
Side and rear surrounds (4 total) will most likely be Zaph's Hi-Vi W5 two-way, http://www.zaphaudio.com/audio-speaker19.html, or Jon Marsh's RS180 Modula MT, http://www.htguide.com/forum/showthread.php4?t=13154... which seems like it might be overkill for home-theater sound effects but would be nice for DVD-audio or SACD music recordings.

The main question I have is on what to use for the center channel. I know some people say a "phantom" center is best but my friend is definitely sold on having one...and I think since the audience may be fairly spread out, then it would be best to have one too. He's planning on using a projector with rather large screen (at least 6' tall) so I was thinking about using two of the previously mentioned surround speaker options as the center, with one placed above the screen and one below. All listeners' heads would be approximately level with the middle of the screen.

Please let me know what you think of this proposed design. Any opinions one way or the other would be appreciated.

Thanks,

Greg

[myhrrhleine]

I'd match the center with the others in front.

[simon5]

You could also simplify everything and do 7-8 identical speakers. That way, you could get nice discounts from resellers, get the same sound from everywhere and also simplify the building process.

I'm sure you could get a nice discount if you say :
"Hey, I want 14 of those mids, 7 of those tweets, 14 resistors, 28 caps and 28 inductors etc etc..."

Like myhrrhleine said, I would at least match the center speaker with the mains.

[cowanrg]

not that you need another opinion, but definately match the center with the mains if you can. it looks like it would work.

also, as the previous two suggested, just build identical speakers for all channels. it will be MUCH easier, and cheaper if you can order things in quantity.

also, im a fan of phantom centers. i have been doing it this way for years. i much prefer it. being in the business, i know of MANY people who do it this way. i know of several $30k+ systems like this. if the mains are good on their own for music, and throw a good center image, a center is not usually necessary. for a smaller MTM like those, it might be advisable, but its not absolutely necessary if price becomes a concern.

[phidauex]

I agree with the identical speakers route. Not everyone can do this for practical reasons, but if you are able, its the best path, and the one officially recommended by THX and others.

Even if you decide not to go all identical speakers, then at least make the fronts and center the same. You really need good timbral matching across that front pan, or it won't sound right.

Unless its just a few people watching at a time, I'd recommend a real center channel. If you are out of the 'sweet spot' on your mains, then center channel imaging isn't as good as a real center.

For the center, I'd use a perforated screen, and put the center channel at head height right behind the screen. Its a remarkably convincing setup, because the sound is actually coming from where the actors are. Its pretty cool, and a very 'professional' type of setup.

Have fun!

peace,
sam

[Gmorris]

Thanks for the input. I need to look more into perforated screens to see how much they may affect the sound and picture.
I still think one MT above and one MT below the screen would give the illusion of sound coming from middle of screen as long as all of the listeners' heads are approximately at the vertical mid-way point, which should not be too difficult to achieve. They would end up being to close to the ceiling/floor however but I can put some acoustic tile or foam to absorb some of the unwanted frequency bounce....