Building a center speaker

[Arne]

I have a HT setup using a Yamaha amp with a Quad 405-II power amp for the front B&W DM220's and the Yamaha driving the rear DM5's and the JBL center. I would like to have a better center as this sounds a bit dull. One of my thoughts is to use an old pair of RS4000's as a basis. They are just lying about and look horrible. However, the EMIT tweeters are in great nick and might add the needed sparkle.

Does anyone know of interesting online designs? And any thoughts on using the tweeters and in what combination for the mids? I have the amp filtering out the lows and redirect those to the front's and sub.

Thanks!

[Andersonix]

What does just one RS4000 sound like as a center?

I made a center channel with just one Tang Band W3-881S (and no filtering at all), and I think it works fine as a center. Smooth and natural for vocals in movies and TV, but not the opposite of dull...

[Arne]

Originally posted by Tosh
[B]What does just one RS4000 sound like as a center?

The trouble is that the RS4000 is a big speaker to use as a center. Besides that the mid and low drivers have suffered from foam deterioration, so they have no sound left in them. And they now look positively horrible. So I was just thinking about recycling the great tweeters and adding something else for mids to it.

[Andersonix]

I realize the foam might be spent, but you would still get an idea of how the old tweeter (plus re-foamed drivers?) would work in a new center channel cabinet. Move one RS4000 to the middle, and adjust your processor to 'small center' or some other way to filter away the bass, and you'll get an idea of the upper midrange and treble character and how it integrates with your main speakers. (You can even use a little sticky tape to keep the drivers from rattling for this test.) How else will you ever know if that tweeter works for you? Blindly buy a new mid, design and build a new center from scratch, and hope for the best? Just try one old speaker as-is!

Now that I've said all that, to ensure some degree of success, you should probably go with a proven little project for a new center (like Zaph, etc.) and re-foam the Infinitys for the basement system...

[Arne]

Originally posted by Tosh
Blindly buy a new mid, design and build a new center from scratch, and hope for the best? Just try one old speaker as-is!

Now that I've said all that, to ensure some degree of success, you should probably go with a proven little project for a new center (like Zaph, etc.) and re-foam the Infinitys for the basement system... [/B]

I know the tweeter works for me as I loved the sound when I had it play a bit of Eric Clapton for me...
I was thinking of buying a new mid driver and combining them in a custom design housing. The tweeters need no accoustic space, so I could build the housing to have the appropriate size for the mid... I know I would probably be better off using a proven design, but I have had these kicking about for a couple of years already and want to do something with their great sound.

I have found the following specs:
40 W max
4500 Hz - 32000 Hz
4 Ohms
90 dB/W/m

Now the next thing would be to find a graph to match a mid...

[Arne]

Ok, I have just looked at the speakers again, and decided I might be able to use the mids as well. However, I want a 'small' center, so using the full system is out. It does make it easier to build the speaker if I do use the mids, because I can then use the filter of the RS4000. The only thing to find out now is the size of the housing needed for the RS4000 mid... I would like to use a double setup with 2 tweeters and 2 mids....

Now I have to find more info on the mid.

[Andersonix]

It is a nice idea to make use of parts you have on hand. But going with your suggestion, you are researching, designing, and building a new center channel, and in the process "ruining" a pair of old speakers that just need refoaming (and painting?). That's a lot of effort with the risk of not being successful (not that you have much to lose).

For an extra $10-15 for a new modern tweeter, you could put together a proven design. (Of course, you don't get the satisfaction from designing it yourself.) And if you find the right project, you could build two more to use with your center as surrounds or even mains one day. Perhaps in this case it's better to start from scratch?

[Arne]

Right now I am very happy with the B&W DM220 front, DM5 back setup. Those are very well balanced to work together, so, unless I find a great pair of electrostats these are going to stay for a while. The JBL center is just a cheap thing. The Infinity's I got when I got a Rotel amp for a family member.

I can follow your reasoning. A proven design would be much easier, and less of a challenge to get right. Ruining the speakers does concern me somewhat. Then again, I do have a set of homebuilt broadbands, another set of JBL's etc. and less space to put them than I have speakers. For the last two years all the Infinity have been doing is gathering dust in the attic. So I thought this would be the best thing that could happen to them.

I just need to figure out the specs of the mids...

I just put one of the RS4000's on top of the tv and it did sound a lot better than my current center... It is just way too massive.

[Andersonix]

Someone help me out here: Aren't there going to be odd lobing problems with so many drivers in this proposed center channel?

Arne: Don't put off getting ESLs. I have regretted it for too long...

[Arne]

Originally posted by Tosh
Arne: Don't put off getting ESLs. I have regretted it for too long...

I know. But I have two small daughters now, so I might have to wait a bit until they know not to touch them.

Btw. I saw a magnepan 5.1 system. That would be good as well.