Cheap M(W)TM(W) setup...

[mavster 10+ year member]

OK before anyone tries to sway this...

I have 4 Pioneer Woofers.... http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=290-023

1). I'm looking to use this for my temp Rears for my two towers in my other thread.

2). Goals; Cheap!

3). Just looking for a tweeter that can cross low enough to mate with these two woofers.

I'm pretty much looking at the Dayton tweeters... have my eye on the one below...

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=275-035

Discuss?

Click to read more...

 

[BrianChia 10+ year member]

What about that crossover I helped you design?

 

[BrianChia 10+ year member]

Also I would try a dipole setup instead of MTM for surrounds.

 

[mavster 10+ year member]

let me add this tweeter into the mix...

http://www.partsexpress.com/pdf/275-030g.pdf

 

[mavster 10+ year member]

Brian, whats this dipole?

Also what XO point do you suggest?

Thanks

 

[BrianChia 10+ year member]

I would use dual DC28 silk domes with each woofer crossed at about 1800hz 2nd order.

Dipole config would have 4 drivers for each speaker with a single woofer and single tweeter on two separate faces. Each face should fire at 30-45 deg. angles from the wall, with each axis wired out of phase with the other. The speaker is thus shaped like a trapezoid or triangle firing out at two different angles. This helps to improve dispersion characteristics and reduces the localizing effect of a direct radiating speaker.

Or you could try a "quadrapole" like this:

http://www.axiomaudio.com/surroundsexplained.html

 

[mavster 10+ year member]

Brian, don't think I could get away with a dual woofer single tweeter setup?

 

[BrianChia 10+ year member]

No, dual woofer dual tweeter.

 

[mavster 10+ year member]

No, dual woofer dual tweeter.

man I feel retarted...I can't seem to make anything work...

 

[mavster 10+ year member]

but you never said why I couldn't do a dual woofer...

just trying to understand it all

 

[BrianChia 10+ year member]

MTM by design creates a directional radiation pattern by using woofer-woofer lobing to control dispersion. In a vertical configuration it helps reduces floor/ceiling reflections and maintains even vertical radiation but also reduces vertical off axis response.

In other words, it's more directional and would hence make a poor choice for a surround speaker.

Dipolar configuration (or bipolar depending on room setup) is much less directional and would better simulate the effect of a movie theater surround sound.

 

[mavster 10+ year member]

Brian, you do realize that I intended to make this a quick cheap project...and I only have 4 woofers..lol

Thats why I suggested the MTM design, because it would only require me to purchase 2 tweeters...

But this is also temporary in the living room....

Because once I can afford to build quality rears, I will probably moves these to my computer or something...

So I figured the MTM design would be sufficient enough to make them useful in any setting.

Just really looking for a concept that would allow me to use the 4 woofers between 2 speakers...without a deep financial devotion to this...

Already spending the money on my front towers and soon after the center channel...

 

[mavster 10+ year member]

bump Brian!?

 

[BrianChia 10+ year member]

Well... you can still do an MTM or 2.5 way TMM if you really want. It just wouldn't make an optimum surround speaker.

You could amaybe try firing the tweeter and one woofer at the wall/ceiling to attempt to diffuse the sound. Or some sort of "tripole" design.