There are at least two companies that make these "P610", Aiyima which sells abroad but I have never used, and Correct which has a large catalogue (I'm running-in their 8" alnico). So unfortunately I can't help you regarding the Aiyima if that's what you saw. I wrote about Correct here:
(alcor66, link to micor55 LX at the bottom)
https://www.diyaudio.com/community/threads/full-range-speaker-photo-gallery.65061/post-7705368
They are each superb in some areas.... The "clone" I mentioned in #57 was the Orgue P610-S (Signature) big alnico $600/pr (drivers) fifteen years ago. Best "midrange" I have.
(alcor66, link to micor55 LX at the bottom)
https://www.diyaudio.com/community/threads/full-range-speaker-photo-gallery.65061/post-7705368
They are each superb in some areas.... The "clone" I mentioned in #57 was the Orgue P610-S (Signature) big alnico $600/pr (drivers) fifteen years ago. Best "midrange" I have.
I finally figured out what was going on.....you live and learn.
When I changed from passive crossover (with relatively run of the mill components) to multi amp DSP active crossover the benefit of the added tweeter became less pronounced. But I still preferred the stacked heils with added tweeter.
But when I use just one heil per side the improvement of an added tweeter was so small I wouldn't bother trying.
So when stacking heils an added tweeter seems beneficial. I would guess the more you stack the more difference it would make.
And.....with drivers as good as the heils you need very high quality crossover parts or go active.....
So I am basically back to my original plan of using single heils without added tweeter crossed at 2Khz with 1st order active crossover. They will function as tweeters in a OB line array with 6x 15" woofers and 20x vintage 12cm alnico full range drivers.
When I changed from passive crossover (with relatively run of the mill components) to multi amp DSP active crossover the benefit of the added tweeter became less pronounced. But I still preferred the stacked heils with added tweeter.
But when I use just one heil per side the improvement of an added tweeter was so small I wouldn't bother trying.
So when stacking heils an added tweeter seems beneficial. I would guess the more you stack the more difference it would make.
And.....with drivers as good as the heils you need very high quality crossover parts or go active.....
So I am basically back to my original plan of using single heils without added tweeter crossed at 2Khz with 1st order active crossover. They will function as tweeters in a OB line array with 6x 15" woofers and 20x vintage 12cm alnico full range drivers.
Sounds like a fun project! Did you measure your stacks? I used a single and they seemed fine wondering what exactly was happening with the stacks?
Rob 🙂
Attachments
I do on occasion do measurements but I mostly like to work by ear. I usually measure to verify my "by ear" outcome or do some final eq. So I didn't measure the stack.
This whole project started when I ordered a sample of every cheap promising driver I could find online in Thailand. They were mostly junk but this one vintage Technics Alnico sounded so sweet. To my ear it sounded so much better than other drivers I had. Even way better than the vifa/peerless tc9fd and a extremely well built Chinese fullrange.
I ended up buying all NOS the seller had for 2usd per driver. So now I have 220 pieces..... Enough to make 5 pairs of line array. They are only rated at 2w but when used as a midrange they can take 10x that before distortion starts to rise. At modest volume these drivers have less than 0.5% distortion above about 250Hz. So as a single midrange they are a bit weak but for a line array they can handle plenty of power.
And I found cheap locally produced 15" woofers that work well in open baffle for only 20usd each. So the Heil is the only part that has a substantial cost.
I can't wait to hear the open baffle bass from 12 15" drivers.
The baffle will be a plywood/cork sheet/plywood sandwich. Absolutely kills any resonances.
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I like mine because they don't "bite" in the top octave! I generally find overly etched, hyper-detailed sound to be unnatural and fatiguing in the long run. The Heils don't get on my nerves. They run from 1500 up in a full OB/dipole system and the system images quite well IMO.
Bill
When I first stacked two Heil's, I had an initial reaction somewhat like yours, a little bit of closed-in feeling sound at very top-end. However, this went away when I tilted up the top Heil just slightly so that both diaphragms are not firing at exact same angle. This REALLY opened up the treble air in my room.
I already ordered the Pyramid bullet tweeters, but after the Heil triple-stack, I think I will probably end up doing what that Japanese gentleman is doing, i.e. firing the bullet backward and reflect off round hard surface..
The very well built and insanely heavy Chinese full range sounds better at first listen, but that is because it has more low end. If I put a steep 200hz high pass on both drivers the vintage Sharp alnico is significantly better sounding.
I am not sure if you are asking a serious question or find it obvious that even a well made 45 watt cast frame double magnet large open spider full range Chi-fi driver can't touch an old cheap stamped frame 2 watt.
I must say -
when I was young, I salvaged a 4inch speaker of similar design from a Telefunken radio and was amazed at its efficiency and sound 🙂
when I was young, I salvaged a 4inch speaker of similar design from a Telefunken radio and was amazed at its efficiency and sound 🙂
My grandfather had an old Telefunken radio that also had shortwave bands. I remember I liked the sound of it a lot. In my mind it was the sonic equivalent of a wood fire....very soothing and natural.
Back before/around the advent of television, the radio console was the family entertainment center, and people still went to live concerts so the standard for fidelity was quite high.
And big alnico.
And big alnico.
You could also try power tapering. Run only one all the way up and low pass the other two... A saw there used to be a smaller AMT3. That would be the ultimate stack. An AMT3 sandwiched between two AMT1's.
No more drivers until I receive the drivers I already have on order 🤔
ESS doesn't even have the small Heil for sale on their website anyway.
ESS doesn't even have the small Heil for sale on their website anyway.
I still love everything about the AMT1, except for the very narrow horizontal dispersion.... When I play some pink noise and move the tweeters up and down it is apparent that the vertical dispersion is as narrow as a line array horn.....far from ideal. So probably the short AMT3 is (was?) a better tweeter.
I was doing some quick and dirty experiments to see if the vertical dispersion can be improved. I made some open cell foam half pyramid shapes to narrow the sound exit and it seems to fix the problem. It seems to almost triple the vertical dispersion angle without changing the sound character much.
I was doing some quick and dirty experiments to see if the vertical dispersion can be improved. I made some open cell foam half pyramid shapes to narrow the sound exit and it seems to fix the problem. It seems to almost triple the vertical dispersion angle without changing the sound character much.
Thanks
That's unfiltered and 18db passive with a 5k notch that's the sim. I ended up going 24db active with 5K notch. This the actual response vs sim. on the active 24db
Rob 🙂