Horizontal MTM Center channel: avoiding off-axis nulls

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More progress!

1: internal enclosures for Alpair5 mid-tweet

2: internal bracing!

3: when clamps are in short supply, railroad ties and brake rotors work wonders...
 

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Weee! built! No crossover's yet, so just doing initial impressions with the crossover in the amp. LR4 at 400hz. I think I'm going to aim for more like 800, but they already sound pretty damned good. going to be doing some emulation with the LspCAD demo here pretty soon.

I'll probably post a thread on the whole project once I have the crossovers finalized. I'm going to be building a matching center channel for these, and some rears channels that are comprised of 2 chr70s each.

So far, these sound really great. More to come
 

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These designs are really interesting.

I was wondering, why do you want to use a MTM (MFM actually) configuration? Can't you better just use one midbass and one fullrange speaker?

I would consider Zaph's 3-way center. But also I would personally choose to use only one midbass. What is the disadvantage of that configuration, apart from 'naked' looks?

Is it sensitivity?
 
Yes, sensitivity and looks. Using two midbass drivers, distortion is lowered since each driver is doing less work, which also means that you can use cheaper midbass drivers and still have good performance. Also, since the crossover to the fullrange driver is low in frequency, this also makes a cheap midwoofer a viable option.

As I've said previously in this thread, I did have my eyes on the Fountek FW168, but I saw a deal on the Peerless drivers so I took advantage of that opportunity.

If I were to build a regular two way "MT" speaker and tip it over for a center channel, it would look very silly indeed.

Regarding the crappy cabinet I previously posted about, I took it to a friend with a speaker building shop in his garage, and we made it usable. It looks a little bit like a patch job, but it'll do for now. In the future I may buy a MTM cabinet from PE to replace it, I would just need to install a chamber for the Fostex driver.

My crossover is mostly built, I just need to get some pipe for a port and wire everything up.
 
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