Last Friday added Townshend Maximum super tweeters to my 107's. They operate from 12k - 90 khz, greatly extending the 107's, which go to 20 khz. The results are...not what I expected...but I'm not sure what to think yet. Had a few hours' listening. I hooked them up and set the level to 3 then 4. Didn't hear any change (there are levels "off" through "max" with 5 steps in between). I then turned them off...didn't notice any obvious difference either. Don't think I was listening for the right thing though. I was expecting lots of extra treble energy, similar to some Apogee ribbons I used to own. These don't do that. There is a little extra metallic shimmer to cymbals, for sure...just a little. The difference I THINK I am hearing is the whole speaker just has a little more realism, more PRAT...just a nice ease to it...it was already a speaker with a commanding "ease" to the sound if that makes sense. Like it COULD kick your ass but it's just going to be confident in the fact that it can if it wants to, lol...but it's just going to cruise along and do what it's supposed to do, knowing it can do whatever is called upon of it (yes I'm weirdly personifying the speakers). But these supertweeters seem to add just a little more of that ease to the sound and also a little more realism to it all.
I wasn't sure they were doing ANYTHING at all. I can't hear them. But then I turned the right one off and left the left one on...felt a pull to the left...the left definitely sounded different. Then did the same to the right...I didn't hear it the other way at first, but I don't think my hearing is all there on the right ear. Tried it again and this time felt the "pull" to the right. So they are doing "something." I turn them off and still think the speakers sound good...but just not QUITE as good...maybe 5-10% less good, if that.
I tried changing phase on the supertweeters and also moving them forward or backward, couldn't perceive any change.
Definitely more trial and error and critical listening needed. So far I THINK they are keepers but not 100% sure yet. They ARE quite expensive. I have a 14 day trial but not sure I'll be able to decide in that time so likely will just keep them and eventually sell them if I'm not convinced. Like any component - amp, preamp, cartridge, cables - the changes can be subtler than we expect and we may not definitively hear them at all until our ears adjust. This is also in that camp where the effect doesn't kick you in the chest, which I guess at this level is a good thing...we're not trying to alter or color the sound, just let it through.
Below is the review that led me to purchase them (from a review on Analogue Seduction). I was in the same boat as James, 107's restored, enjoying them, but thought I'd try for more. I will say, the speakers are sounding very good, probably better than ever, SOMEHOW!
Towhshend Maximum Super Tweeters
Wednesday, 6 April 2016 | James
Well... I purchased these more to satisfy my curiosity after reading about how they could take a good system and add more clarity and coherence across the entire frequency spectrum. I have had them in my system for three days now and by golly, they really do work. As stated elsewhere, if you isolate them you can just barely hear something going on but it is hardly high in output or very recognizable as musical at least that I can detect anyway. However, add them back to your full-range speakers and it is a whole different story. I recently rebuilt my aging KEF R107 speakers that had ceased working due to completely disintegrated surrounds on all four woofers and tweeters with their voice coils stuck in 30 year old, dried up Ferro Fluid. With rebuild woofers and having disassembled, cleaned and recharged the tweeters, they were sounding very fine indeed so there was no compelling reason to fuss with them by adding super tweeters but boy, am I glad I did! These are still one of the best sounding speakers I have ever heard but with the super tweeter added in, they are elevated to something truly special. The claims others have made are all accurate. The clarity, space and ease across the entire spectrum is not subtle. My wife who knows nothing about any of this when asked to take a listed after I had installed them commented that the system sounded better than ever and proceeded to pretty much describe the improvements in similar terms. Keep in mind she had no idea the tweeters had been added and so was in no way biased. That is a pretty strong commendation in my book. Anyway, these things are really something special and you don't need to have perfect hearing to appreciate the improvements. I am testament to that because my hearing is hardly in pristine shape after all the years of playing in a rock band on the side off an on for the last 45 years. Highly recommended!