Center Channel Prototype done..

[kingdaddy]

Finally have my Center Channel ready to load with drivers, should be playing this weekend so I can play with the crossover alignment. I have made this speaker to match my mains so I wanted to make them adjustable to see if I can make the off-axis any better by tilting the mids in or out. I have no idea if this will work but it might be fun to experiment and see what audible differences there may be by messing with the lobeing.

The drivers are almost the same as the mains; SS8530-K01 (instead of K00) and I went to a sealed alignment this time. The tweeter is again the Vifa XT25 shielded version. I'm hoping that I will be able to compromise the dispersion problems of laying a MTM on its side with the tweeter offset and the mids adjustable. I ran into many problems trying to make the adjustment mechanism, but after I figured out how to make a articulating threaded receptacle I was finally able to make the adjustment with a single knob, which is what I was going for. The last project with independent mid enclosures was just too difficult to get aligned so I connected them together this time. I had to use a rod with left hand thread on one end and right hand thread on the other; also, I made the articulating receptacles with corresponding left and right hand threads. The final speaker will have the base, knob and adjustment bracket all oak.

[kingdaddy]

Wish I could figure out how to attach more then one picture. Here is the front.

[kingdaddy]

The adjustment range is about 4.5 inches in or out. Should be enough to make some audible difference off-axis.

[tiroth]

Beautiful work, and it sounds like some great engineering as well.

[kingdaddy]

Thanks:

I'm pretty happy with the adjusting mechnism, it works pretty smooth and had the resolution I want, very sturdy as well. Next I'll need to come up with a nice looking stand.

[PHilgeman]

Great work, I have seen your mains before...

I think they key will be to get a low frequency, high order crossover

[kingdaddy]

Probably 4th order 2.8K to start with, so far I haven’t had much luck going much lower then 2.5K with this tweeter. At 2.8 you can use almost any order with good success, I'm just curious of the lobing errors and hope I can get around them. I should know more this weekend after listening.

[conscious]

Very cool stuff, k-daddy.

I don't know if you're going to be able to get away from the lobing with the 2 mid/woofs though:
http://www.soundandvisionmag.com/ide...&searchstring=

[Paradise_Ice]

I have to agree, very beautiful work, will you vaneer them or just varnish them and show the work off?

how will this sit on or under your TV?

[kingdaddy]

Definitely a change in off-axis response when the mids are tilted to one extreme or the other, just cant tell what’s going on until I can figure out a better setup to measure, speaker workshop is giving me calibration problems again. So far it sounds very good as is, the crossover was already set for this tweeter (2.8K 4th) and the mid/woofs are very versatile and seem to do quite well in a smallish sealed cabinet, very good bass response from my early listening tests. Didn’t have much time to do much tweaking but I may not have to do much other then find the proper tilt angle for my listening position, I can make a very fine narrow sweet spot with a inward tilt, that’s about all I can confirm with my ears for now. The speaker will set under the projection screen once I get a stand made, it can be converted to a vertical array if this expermint doesnt work.

Here is some pictures with the drivers in place.
SS8530-K01 shielded woofer
Vifa XT25 shielded tweeter