W-MT-W Work-in-progress pics and rambling cause I'm bored

[tresch]

I'm bored and about to go to bed and excited about building speakers and so I'm going to babble at you guys.

Nothing pretty, just whipped up a quick prototype box for final acoustic measurements and crossover testing. One Alpair5 as mid-tweet and two Dayton DA175 6.5" woofers. Sealed with F3 of about 50-55hz. This will be a center channel for a home theater system. Left and right channels will either be sealed towers or ported, haven't decided yet. As it's an HT with a dedicated subwoofer, I'm thinking of going sealed to keep everything as similar as possible, reduce phase problems, keep it simple, tight, clean, etc.

From initial open air testing, and from listening to the alpair5 in a tiny sealed box I build for it, so far it seems awesome, and I think it's going to do great as a mid-tweet. The only worry I have is that in HT systems the listener may be in any number of positions, and thus the "beaming" issue of the larger tweeter could get ugly. The Alpair5 has a rise in response above 10k to deal with this for off-axis listening, but in HT the listener might be on-axis on one speaker and off on the other. I think I'm just going to have to do some listening and maybe filter out some of that rise so it's not too harsh when on-axis.

Aside from the, the A5 impresses in low-mid and upper-bass frequencies. Because of this I'm planning on crossing over fairly low, at about 500hz, with an easy 2nd order linkwitz. This makes my woofer selection MUCH more flexible, as I don't have to worry about cone break-ups and such, and merely have to look at low-end response and distortion.

Thanks to zaphaudio's site, I found the DA175 as a perfect match of price to performance-that-i-need. It plays lower and with equal or less harmonic distortion at those lower frequencies (according to Zaph, anyway) than many drivers twice their cost. The downside is the aluminum cone has some breakup issues around 2-3k, which I get to gleefully ignore! They're only $20 each! Thus, two. Thus, less distortion, more power handling, etc etc.

Plus, they're also shiny and silver, so they go well with the grey Alpair

More to come!