How would you interpret this dipole FR chart?

[sfdoddsy]

I'm trying out an active hybrid electrostat at the moment that has received rave reviews here in Australia against my digital Orions.

The designer sent me a FR chart, with measurements taken at 2m. It corresponds quite well with what I have measured and with what I am hearing.

I suspect that not enough has been done to counteract dipole cancellation where the ESL panel meets the monopole bass section. Would the wise minds here concur?

[Coconutout]

hi steve, an off topic question but i love the painting in your last picture on your blog. who's the artist?

edit: love your blog

still can't provide an opinion on your graph, however. sorry.

[JonMarsh]

Rta

First, I agree that the integration between the dynamic woofer and the ESL looks suspicious to me, given the dip in the area between 300 and 800 Hz. More of concern, to me, given that this is an RTA measurement, which averages the total ongoing response (room sound plus direct sound), is the rising response above 3 kHz! With an RTA, and a speaker with fairly flat on axis and power response, you usually see a drop in the energy above 5-8 kHz because the reflected sound loses high frequency content.

From my perspective, a good gated measurement with a half hanning window would make me more comfortable about assessing the overall response.

Another statement I'm going to make here is that combining a monopole woofer with a dipole (possibly line source?) ESL is problematic due to the fall off with distance not being consistent between the two very different radiating sections. You kind of have to design it for one distance...

Successful hybrid ESL systems I've heard, like the old Levinson HQD from the 70's, used the ESL pretty much all the way down to 100 or 125, and relied on room boundary reinforcement to help the bass response at greater listening distances compared with the effective line source ESL.

[sfdoddsy]

Thanks Jon. It actually does roll off in room. Here are my own measurements of the speaker in question, nearfield and from the listening position.

To my ear and mic it has problems in the crossover area (250Hz or so) with dipole roll-off and the bass transition you mention. The vertical dispersion isn't ideal either.

In spite of that it actually sounds very nice.

[gainphile]

A planar like that would have multilobe, so measuring a single point in room would not tell anything?

[JonMarsh]

Thanks Jon. It actually does roll off in room. Here are my own measurements of the speaker in question, nearfield and from the listening position.

To my ear and mic it has problems in the crossover area (250Hz or so) with dipole roll-off and the bass transition you mention. The vertical dispersion isn't ideal either.

In spite of that it actually sounds very nice.

Much more informative measurements!

Designed for near field perhaps? Sounding nice is likely due to the inherently low linear distortion and lack of resonance in the panels. Me, I'm partial to Quad 57's. :W

Ans you must have a very lively room in the top end!

[sfdoddsy]

hi steve, an off topic question but i love the painting in your last picture on your blog. who's the artist?

edit: love your blog

still can't provide an opinion on your graph, however. sorry.

If you mean the last picture showing the perspex bedroom dipoles, the picture is by an Australian artist called Tez.

http://www.skullpussy.com/

If you mean the pic in 'Cobras and Bruts' it is by Karel Appel.

[Paul K.]

Coconutout, I've sent you a couple of emails yesterday and one today. I was answering the question you asked about "that" angle to cut and want to make sure you received my emails and everything was clear?
Paul

hi steve, an off topic question but i love the painting in your last picture on your blog. who's the artist?

edit: love your blog

still can't provide an opinion on your graph, however. sorry.