My collegue with the Quad speakers is a bit sceptical about the inherent speed of a mechanical tweeter compared to the one in a static (or plasma) design. My guess is that Danley uses mechanical tweeters in the SM60's, but I couldn't easily find info on what category of tweeter is used and how fast this is.
Yes I can understand how he might think that, one naturally uses a car analogy here.
An experiment which will cause much head scratching, is one that reveals what is actually happening.
For a direct radiator, mass actually has no impact on the speed of the device, I know this sounds ridiculous (in the car analogue domain) but here is how you can prove it. Take a woofer you can toss out and out it in a box. Measure the response all the way up high, examine it's impulse response.
Now, glue a coil of solder to the joint of the dustcap and cone body so that you have substantially increased the mms (moving mass). Now, re measure and you see the mass has reduced the sensitivity and lowered the low corner BUT the hf response and attack part of the impulse is UNCHANGED..
The reason is to produce flat response, the direct radiator needs an acceleration response, NOT velocity and so increasing the mass doesn't affect the hf corner at all.
In the ESS system, the need for low moving mass is related to the desired sensitivity and weakness of the force that the ES field can apply on it.
In the case of the Synergy horns, I am not sure which is better to copy and paste previously written text or to supply a link. Being lazy, I am posting a couple links that explain what I am trying to do, how this is different and how the ESL-63 played a key role.http://www.whatsbestforum.com/showth...t=danley+esl63http://www.whatsbestforum.com/showth...lignment/page7
A few thoughts on some other posts, I wish I had more time but we are in the lead up to a big trade show, so writing is more like taking a relaxing break while pressed for time.
Yes it is a coax driver but used unconventionally as both a mid and high frequency compression driver and not a direct radiator with a time offset.. It was part of the original patent but the SM-60 had to wait until we could mold a horn with the proper passages and shape.
The BIG advantage of horns like this is they do not produce lobes and nulls and have a large front to back energy ratio. It is that directivity that causes them to measure very similarly at the LP as at a meter or two.
In commercial sound, a KEY to producing words you can understand in a terrible room is that kind of directivity, that is why our horns are as large as possible given the cabinet size and why all the sound comes from one origin.
It was also possible to develop and apply a crossover that eliminated the phase shift (time spread) normally found in crossovers and so boxes like the SH-50 can reproduce a square wave over a wide band, over a large range of positions (the result of being a single acoustic source in time and space).
In the home, that means the speakers nearfield (where the direct sound is louder than the reflected) extends farther into the room, preserves more of the recorded signal (reflections generally compete with the desired signal)
For those wishing to EQ the Synergy horns, this is an ideal use for eq BUT the flaws of EQ are also more easily heard. By flaws, that isn't the right word as when EQ is right, it has no flaws, the problem is trying to EQ something that is not EQ-able acoustically.
If your going to EQ them, please do this when you can.
Set the speaker up on a stool or mid height in your room. If you can do this outdoors, that is vastly better. Keep the mic a meter or more away. The goal is to measure the speaker only, not to include reflections or room stuff. This is important as the speaker IS the only part you can actually fix.
Once you have it like you want it outdoors, then move it back to your room.
In room, It is safe to cut or lower peaks or mounds and it is safe to tilt, shelve or apply a broad boost. Generally DO NOT try to fill in deep cancellation notches.
Best regards and happy listening