Center matching for the Mosaics...Fresco close but...stupid idea?

So I have Mosaics as my mains and a Fresco as the center. The Fresco has the same drivers as the Mosaics, so you'd think the center match would be close...but it isn't. It just isn't quite right, sounding 'smaller' and more boxy than the Mosaics.

i ASSUME this is because the Mosaics have a rear wave (I think?) and the Fresco doesn't.

What if I took a second Fresco, placed it backwards to the center channel so it fires a back wave? Would that improve matching or am I on the stupid pills again?

So, I went ahead and did this because, why not?! So I had an old Acculine A1 speaker which happens to use the exact same Radia planar driver that the Fresco's use. The speaker can be bi-amped so that signal only goes to the tweeter, through the speaker crossover. Using my receiver pre-outs, and a second amplifier, I ran the center signal to the Acculine, faced directly backwards and behind my Fresco.

I don't know if I got the phase exactly right (I'm sure I haven't) but it DID improve matching with my Mosaics which DO have a backwave. So, now I have a Fresco with a backwave, but it is ugly. It did give the center channel more airiness and makes the Fresco feel less boxy when compared to the Mosaics. Downside is the center voices are slightly 'smeared' instead of coming directly from the speakers. I'm sure I have some cancellation going on, but don't really know what to do about that. I might hide the ugliness with some material and experiment further, but I'm interested so far!

Hola akm3. Just thinking loud of what you did, you are connecting them as a Bi-polar configuration. Why don´t you try Di-polar and listen? You have to reverse the back fresco its polarity only. The red color is - and the black is +. The electrostatic speaker is this way. it is a Di-polar driver. Also bring the center (the two of them) a little bit forward from their back wall. When you are doing a change in your system, leave it for some time, to get used of the new sound. If you do not like it, then go back right where you were before. Tell us what happened please.

roberto said:

Hola akm3. Just thinking loud of what you did, you are connecting them as a Bi-polar configuration. Why don´t you try Di-polar and listen? You have to reverse the back fresco its polarity only. The red color is - and the black is +. The electrostatic speaker is this way. it is a Di-polar driver. Also bring the center (the two of them) a little bit forward from their back wall. When you are doing a change in your system, leave it for some time, to get used of the new sound. If you do not like it, then go back right where you were before. Tell us what happened please.

Click to expand...

Thanks Roberto, I will try this. What I'm wondering though since it is a speaker behind another speaker (instead of a true bi or di-polar) the distance the back tweeter is from the front tweeter messes with phase too doesn't it? One should sound 'better' depending on how far from the wall it is, right?

It's pretty subtle which I like, but it gives it a bit of space and sheen and sparkle around the center channel that is closer to what the mosaics do so it seems good as long as I'm not creating weird distortions or cancellations.

Hey akm3, you are not the only who had thought about it. Some time ago, Mirage used Bi-polar array, and also Definitive tech. They believe that using normal polarity on both ways, firing to the front and firing to the back, gave them the results that they were seeking...but still, had they flaws. Perhaps with the Di-polar array, the effect will be less apparent, but you will get the focus that you are looking for with better spread signal... bring your Mosaics a little closer to them, it will not shrink the image, you could get to disappear them with wide and better sense of 3D. try it, perhaps you might like it. Trust your ears! They will guide you better than any of my explanations...happy listening!

I've been running it bipolar for a few days now, and I notice no negatives. The center speaker now more closely matches the left/right to the point it is much more difficult to tell. It is a definite improvement. I'll try dipolar now for a few days.

That's the best way to do it. Remember that our immediate memory only last less than 20 seconds to a trained ears...you can fool your brain, if you start to do changes...spend some time with each change, and you can tell the differences. Have on hand a notebook and write down your findings. Make the comparisons of your findings with your ears and notes. Happy listening!