Center Channel Design

[TKoP]

So here’s the situation I find myself in..

A while ago, I helped a friend design and build a pair of speakers. He ending buying enough parts for a third center channel and is now eager to use the parts he paid for.

The thing is that part of his design criteria is that he wanted something really wide and shallow – the speaker is wider than it is deep. I don’t remember the reason now, but that’s what we have.

This is going to be a problem with the center channel. There is no way he’ll want to have a similar upright speaker for the center. If he just builds a speaker similar to the right and left speaker and tilt it on its side, it’ll probably not work either because the drivers themselves are offset from both the top to bottom as well as from side to side.

So, I know these all will make a difference, but how much:

• Moving the drivers so they’re centered in the box
• Coming up with a more conventional designed box (i.e., it’s more deep than it is wide) -- although, keeping the same internal volume

The other thing – he’s too impatient. I don’t have the time to look into all the design issues, so any general advice would be appreciated.

 

[Rope]

So here’s the situation I find myself in..

A while ago, I helped a friend design and build a pair of speakers. He ending buying enough parts for a third center channel and is now eager to use the parts he paid for.

The thing is that part of his design criteria is that he wanted something really wide and shallow – the speaker is wider than it is deep. I don’t remember the reason now, but that’s what we have.

This is going to be a problem with the center channel. There is no way he’ll want to have a similar upright speaker for the center. If he just builds a speaker similar to the right and left speaker and tilt it on its side, it’ll probably not work either because the drivers themselves are offset from both the top to bottom as well as from side to side.
So, I know these all will make a difference, but how much:

• Moving the drivers so they’re centered in the box
• Coming up with a more conventional designed box (i.e., it’s more deep than it is wide) -- although, keeping the same internal volume

The other thing – he’s too impatient. I don’t have the time to look into all the design issues, so any general advice would be appreciated.

Rope

 

[Maximo]

YEah he's trying to avoid his spekaers sounding like those shitty PMCs. :mrgreen:

 

[Rope]

YEah he's trying to avoid his spekaers sounding like those shitty PCMs. :mrgreen:

PCMs??

Rope

BTW, I wouldn't want my speakers to sound like PCMs either. :happy-smileygiantred:

 

[TKoP]

That is only an extreme option -- the speaker's shape just doesn't lend itself that kind of set up.

 

[Yesfan70]

So here’s the situation I find myself in..

A while ago, I helped a friend design and build a pair of speakers. He ending buying enough parts for a third center channel and is now eager to use the parts he paid for.

The thing is that part of his design criteria is that he wanted something really wide and shallow – the speaker is wider than it is deep. I don’t remember the reason now, but that’s what we have.

This is going to be a problem with the center channel. There is no way he’ll want to have a similar upright speaker for the center. If he just builds a speaker similar to the right and left speaker and tilt it on its side, it’ll probably not work either because the drivers themselves are offset from both the top to bottom as well as from side to side.
So, I know these all will make a difference, but how much:

• Moving the drivers so they’re centered in the box
• Coming up with a more conventional designed box (i.e., it’s more deep than it is wide) -- although, keeping the same internal volume

The other thing – he’s too impatient. I don’t have the time to look into all the design issues, so any general advice would be appreciated.

Rope

I asked a similar question a while back (building a tower cab for a MTM bookshelf and having the drivers in a TMM array), and was told keeping the driver orientation the same is as important as keeping the cabinet volume the same. The center and towers in Rope's pic are different, but I wonder if PMC used a different crossover design for the center speaker to keep the timbre matching between the speakers.

That being said, unless your friend is geeked out with this hobby like the rest of us, I'd take a chance and build a custom center speaker to match his others. Check out this guy's custom center from the Klipsch forums.

KLF-30 center mod

I know that guy's situation is different, but thought it was a good read and may give you all some ideas.

 

[Rope]

PMC didn't release the CB-6 (center channel) for sale until 3 1/2 years after the first OB-1 was sold. They totally redesigned the OB-1 to manufacture one laying on its side. In doing so, they extracted 16" from the bottom, increased the number of transmission tunnel chambers, and rearranged the drivers, which are all identical to the OB-1. I've never read anything about the CB-6 crossover design, although I'm reasonably certain they would have tweaked it in order to obtain the very similar voicing of the OB-1.

Rope