Hard Audio - Ceramic Speakers

Dr. Toole has said that EQ can help for room effects, but it can't fix a poorly designed speaker.  Frequency response is important, but you can't just look at on-axis.  A smooth and predictable off-axis response that mirrors on on-axis response (though with a more downward slope as you move further off axis due to directivity of the tweeters) is just as important as a smooth on-axis response, and EQ often doesn't fix problems in off-axis response.  

So, proper EQ can help make a good speaker sound even better in a room, it can't fix a speaker with fundamental design flaws.

As far as the various levels of Revel speakers go, while all are designed to exhibit the best on and off-axis response as possible at their various price points, there are benefits moving up the line. 

Moving from Concerta2 to Performa3 (and now Performa3 Be) to Ultima2 you get greater bass extension, greater power handling, greater dynamic range capability, less dynamic compression, less distortion at extreme dynamic levels, etc (plus of course the intangibles like more nicely finished cabinets and such).

Playing material without much bass content at a lower volume the Concerta2 F35 should sound remarkably like the Ultima2 Salon2.   Change the material to something with deep bass content and a very wide dynamic range played at reference levels and the differences will become apparent.  

The new drivers in the Performa3 Be offer more dynamic headroom, lower distortion at extreme volume levels, and stronger motor structure/better cooling to decrease dynamic compression.

AFAIK, damping the FR damps the ringing as well. Something about this is how minimum-phase devices work.

It’s not intuitive. We believe that a passive or active EQ would affect the frequency but not time domain, but I’ve read otherwise.

In rooms, the same principle works, with some help from bass traps. 

Best,

E

In theory, with everything equal and no other speaker distortion mechanisms then Dr Toole may be correct: pure ringing at the fundamental can be removed with a notch filter it. However, in practice speakers are not perfectly linear and have limited operating range and other forms of distortion - so the speakers won’t sound the same -  so in practice it is far better to have a speaker with a flat response to begin with then to compensate using electronics. 

The kind of ringing that is of most concern is that from wobbling modes from energy within the cone diaphragm itself. This sounds splashy or dirty and is not necessarily harmonically related to the music.

I also want to point out that many, many drivers have break up modes / ringing in the top end of their usable range. Dealing with this is not all that difficult or new. 

How it is dealt with in crossover design depends a great deal on the next component up the frequency spectrum. Low pass filters may put the ringig 20-30dB or more down in response making a specific notch filter irrelevant. All the fans of the Focal inverted domes have ultrasonic ringing which they don't seem to complain about very much either. :) 

And sometimes we deal with the resonance by designing speakers not to be toed in. :) 

Best,

E

Kharma Grande Ceramique loudspeakers uses a 7 inch ceramic midrange and in my opinion still among the best. I have had them for a decade and they still blow me away