# Center Channel Advice



## letzleta (Jan 11, 2007)

I will start with the current setup.
Receiver - HK AVR254
5 speakers - JBL E30's
Sub - DIY Sonosub (15" Dayton Titanic w/500 watt Bash plate amp)

I would like to move to a 7.1 setup from my current 5.1 setup. I have 6 E30's that could be used.

I am trying to decide if I want to build a center channel and try to sonically match the E30's, or if I should just build a nice center channel and eventually build 6 more speakers to match. I built my sub, but have no experience building other speakers. I believe I want to stay with bookshelf size speakers. Given that, I think 8 inch woofers would be the largest I would go with and should go low enough to blend well with the sub.

So, I would love to hear some opinions on where I should go from here (2-way, 3-way, etc). I use the system for TV, PS3, Movies, and Music (including concert Blu-ray's and DVD's). Most of the time it is TV and PS3 though. I will admit that I am a big music fan though and enjoy concerts on the system.

I would like to keep the budget at ~250 or less in order to keep making 6 more possible. I feel that I should be able to build something significantly better than the E30's for 250 a piece.


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## hddummy (Mar 9, 2007)

I've been considering building a set of speakers too. I've got my eye on the Zaph designed kits over at Madisound. That might be a touch over your ~250 budget, but I would recommend only building LCR speakers if you are happy using your E30's as surround speakers. That is, at least, the way I would approach the situation if I was you. Keep four E30's for surrounds and get/build new LCR speakers. That way, you main three speakers all match and your surrounds all match.


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## letzleta (Jan 11, 2007)

I like the LCR idea. Then I could build 4 more if I wanted to complete the system or just stick with the E30 rears. Also, those kits look nice. I will keep those on the list of possible builds.


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## fbov (Aug 28, 2008)

If you're interested in building a "proven design" (the only reasonable recommendation) here's where to look. 
http://techtalk.parts-express.com/showpost.php?p=1571811&postcount=1

I'll second the idea of building a matched LCR set and use the E30's for surrounds for now, as that's what I've done. I'm now building matching surrounds, but for matched sensitivity, not timbre matching. 

Here are a few things to keep in mind, as I learned about 26 months ago.
- don't go small on the CC; it gets as much or more power than the L/R
- be careful which CC design you use. this comes in two parts
a) many CCs go into furniture around the TV, rather than standing away flat surfaces like walls, shelf doors and TVs. This requires a different crossover design, referred to as "on-wall/in-wall" vs. free-standing. The issue is baffle step compensation (BSC) and it's real (speaking form personal experience)
b) many CCs are "sideways MTMs." The MTM is a vertical design with certain advantages in efficiency and dispersion due to their double woofer geometry. When turned sideways, this becomes a problem as there are major interference nulls off axis. There are three solutions, stay vertical, use a WMTW (ie. a 3-way) with vertical mid and tweet, or use an MTM designed as a CC, with reduced driver spacing and a very low crossover point. I've done neither and mine sounds fine to me, but I'm no musician.

Good luck!
Frank


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## letzleta (Jan 11, 2007)

This is great information. Thanks to all.

Based on the last post, I am wondering if I should skip the center channel all together. In my current setup, I am using all E30's laid on their sides. My home theater utilizes a projector, and based on the room layout I decided to hang the speakers from the ceiling. In the current configuration, it would not be possible to have the speakers stand up because they would interfere with the front projection setup. I believe placing the speaker below the screen would be too low and furniture would obstruct the path of the sound.


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## fbov (Aug 28, 2008)

The main reason for a CC is that it enlarges the seating region where the center information is heard to be coming from the middle, so it depends on your layout. Phantom center images are only centered for those seats that are equidistant from the front speakers. Also consider that TV especially relies on the CC for most of it's sound, be it a talking head or centered action. 

I agree it would be odd to have L/R above screen level and CC below. I'm not sure if that's more objectionable than a seat-dependent center image location. My CC is a good foot below my screen, and the L/R roughly screen level and it does sound a bit below the action without any furniture in the way. However, it sounds a lot better to me than a phantom image; I'm not going back. Experiment yourself before building a cc; see what you like.

HAve fun,
Frank


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## lsiberian (Mar 24, 2009)

I'm gonna shoot it to you straight. Building a speaker is a lot more work than a sub. You gotta get the crossovers right, drivers right, and you need to brace and dampen it very well to get great results. The good news is you can out do commercial design pretty easily. But it's still a lot more involved. 

Many have suggested a kit and I'd agree with that. However if you only want a center then the Loki coaxial kit is actually the most ideal setup for a center specific speaker. Since you are building the speaker you can angle the baffle toward your seating area. You just won't find a better. If interested I can get you in touch with a gentlemen who has a TL design for a center using that very kit.


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## Mike Cason (Mar 17, 2007)

I feel like a traitor coming back to the forums. Everyone here has been such a great help and now that I've finished building my 7 year project, I don't get here much. I'm also finally working again which is great!

I have to agree with fbov about the center speaker being capable of handling a lot of power. I tried building mine with some cheap 10" HiVi Kevlar midwoofers, then upgraded immediately to the Lambda 12"TDs drivers from Acoustic Elegance. I have a pair of them in each of my mains and the center speaker now and the soundstage is just incredible. I'm powering them with the Emotiva 3 channel supercharger from my Denon 5308 and holy mackerel, movies are very real even though the imaging from my mains were already superior. The center speaker does take a lot of power and is very vocal. It weighs in at 130 lbs. Here is a link if you are curious: http://www.hometheatershack.com/for...0-kevlar-center-speaker-build.html#post232858

For many years I was an only stereo music guy, but with our new movies and recording studios, I have changed my mind to be open to the music sources ie SACDs, DVD music concerts, and etc. with all of the different decoding choices most AVRs can produce. The center speaker is indeed a novel addition to complete your "home theater" system.


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## Owen Bartley (Oct 18, 2006)

I'll back fbov on his points too, don't go too small with your CC, because it really does do most of the work with movies. You want to have something that can sustain loud dialogue and effects without bottoming drivers or buzzing tweeters. You do also want it to be a tonal match to your other speakers ideally, which is tough when going outside the speaker's family, but if you're up for building new L/C/R speakers, it sounds like a kit would be the way to go.


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## aceinc (Oct 24, 2006)

Here is a center channel I threw together a few years ago;

http://www.hometheatershack.com/forums/diy-speakers/4195-inexpensive-easy-center-channel-2.html

I mention it not to say you should build this beast, but to suggest that you can get decent sound out of smaller drivers. I am still using the speaker as the center in my main system, and I like the sound. It is a bit more efficient than my other speakers, but it plays well with my system.

One thing that I was concerned about was "voicing." I have a pair of KEF 105.4 speakers for my fronts. I suspect it would be nigh unto impossible to get something with the same voicing as those. I just decided to build this speaker, and see what happened. Well, if I switch back and forth between the center and the fronts I can certainly hear a difference. I find neither unpleasant. When they are playing together, I do not notice problem, and the sound blends well. I do not know if;

a) I got lucky?
b) I do not have a discriminating enough ear?
c) Voicing differences unless egregious are "The Emperor's new clothes."

BTW I too am driving my system with Emotiva, XPA-2 for the fronts, XPA-3 for the center & rears and an XPA-2 for my subwoofer system.


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