Alpair 1.5-way Speaker?

[pizzachef]

I am relatively new to speaker building. I built the microtower bipoles with Alpair 7's as my first project and I love them. I use them for music. With the Alpair 12 out of stock when I wanted to do some home theater speakers, I then built three pensil 10's for my home theater.

I feel like the Alpair 10's have been nice for dialog clarity but maybe lack a little oomph in the low end, particularly since the room they are in is pretty large. I fear that at loud volumes I am pushing the x-max and maybe getting some distortion. My solution for now is to raise the crossover to the subwoofers.

I was wondering about the possibility of building a transmission line type design but with 2 matching drivers, say Alpair 10's. They would cross over relatively low such that only one would be firing for treble and midrange, eliminating any cancellation effects at higher frequencies. Down low they would share the load, effectively doubling the driver area and as a bonus providing baffle step compensation.

I know this would be less efficient and the crossover in some sense defeats part of the purpose of full-range drivers, but I feel this is minimal since it is crossing over between identical drivers. Also, my home theater amp is sufficiently massive as to make the question of efficiency largely irrelevant, I think.

Any comments? I have tried to find a thread like this and failed. Is this a reasonable idea or is there something I am missing.

[pizzachef]

LOL, the moment I post this I see the dual driver thread about 5 down. So dual drivers seem to be doable. I guess I still would ask about a full dual driver vs. 1.5-way. My sense is that the dual driver 1-way speaker further down in this forum is more for nearfield, and that I would have problems with it in a home theater, but again I may be misunderstanding the interference issue between identical drivers.

[planet10]

The concept is fine. Do note that the A10.2 goes lower than the A12. And that 2 A10s aren't much more $$$ than 1 x A12 (if you could get them)

There are a number of Twins in my mini Onken plansets.

Here is one Toppsy did with A10.1



dave

[pizzachef]

Beautiful. I feel another project coming on. This speaker building thing is relatively new to me but strangely addictive.

Are these straight one-way designs? If so, aren't there some sort of interference pattern problems for wavelengths shorter than the driver separation?

[planet10]

Toppsy ran it as a straight 1-way... he didn't comment on any audible issues with combing.

But there are a number of ways to filter them for different results with different amps.

dave

[doorman]

Lovely build,as usual, Colin: Care to share your listening impressions vis a vis
the Mar-Ken cabs w/ single 10.2's?
Best
Don

[pizzachef]

Thanks. I found Toppsy's original article on his build. It is here: audio-talk :: View topic - My Latest and Last Speaker Build

He later did a MTM design using fostex drivers here: audio-talk :: View topic - Fonken FE167eN + FT17H MTM Floorstanders

I may have to try this