The QTS being high in Bionor makes sense due to baffle design (open at back) and “infinite type” at front. For 95% of standard horn loading applications, low QTS is used. This example is unusual.
David Karmeli's Natural Sound in Utah
- Thread starter PeterA
- Start date
The QTS being high in Bionor makes sense due to baffle design (open at back) and “infinite type” at front. For 95% of standard horn loading applications, low QTS is used. This example is unusual.
It’s open at the back for the woofer? A high Qts makes perfect sense then or it would likely sound too lean.
It's "open" but has a protective cloth over it. I'd be curious how easy it is to breath through it. I guess David could tell us if he likes.
Yes, that's how silvercore had it, he purposefully increased QTS of his dual 18 inch woofers as he was using open back. His SETs Have drive and power so he could. Mirrophonic too had open back not sure what their QTS is.
Closed back like altecs would have lower qts
Last edited:
I remember first seeing this approach with the Carver Amazing ribbon hybrid speakers. Bob Carver deliberately used very high Qts drivers (small magnetic motors) for his open baffle to offset the dipole cancellation, rather than making super wide baffles. Most bass panels (like Apogees) are similarly tuned so that the net response is relatively flat.
One problem with low Qts drivers is that they don't work well with high damping factor amplifiers...particularly in horn loaded designs. The bass then is so overdamped it is virtually non-existent. We played with a Devialet on my Odeons and we had to boost the bass (something you can do in a Devialet) by 9 dB to get something similar to what I got from the Aries Cerat Genus... but then it had other issues like flat soundstage and a dryness to the mids...another story...
Yes Kedar frequently points out this fact to others as he knows very well this issue as heard with the Altec woofers.
Yes that's also what happens when people use high grip amps on altecs. The driver is already damped so gets over damped. So it chokes the bass.
Leif also has open back with a cloth that has certain perforations. But his JBL 2220a is 0.17 qts, and them he is going to separate woofers again at 75 Hz which also have an open ball
Not to mention, nearly all SS I have heard on high sensitivity horns sounds like fingernails on a chalkboard....
Tim, it was not just one system, but across all the different systems we heard together with the different amps and speakers and even the proto type turntable and vintage cartridge in a different room. The skill required to do this across so many variables is truly remarkable.
I noticed there is a pair of the pioneer TAD 2401 on eBay. I'd like to hear these. The Bionors look a we bit largish for my space. 
You joining the SET/horn "cult" too?I noticed there is a pair of the pioneer TAD 2401 on eBay. I'd like to hear these. The Bionors look a we bit largish for my space.
You joining the SET/horn "cult" too?
I'd be rejoining, to be accurate. In the past, there were always certain sonic issues I couldn't work around. So, no immediate plans or desire, but I'm always open to hearing new things.
I heard the duo a couple times. I am curious about the Viking L'Instrument. But it's only 98 dB/W/m. Which would probably mean sound would suffer with the 2W type 50 amp I'd want to use. Though my room isn't huge. I sit about 3.5m from the speakers.
I asked because such hybrids like uno and duo usually have a lot of issues.
I guess you are looking at Slagle's type 50
Integration can be an issue. An example I disliked quite a bit - the PAP in horn version, to me, is very lackluster. My general problem with horns, aside from integration, has always been the lack of plankton. Generally, dynamic as hell, and then lacking detail. This is assuming you get past the more common issues of honky sound and wonky timbre. Many newer designs do. At the California Audio Show in 2019, the best horn room to me had the giant Acapellas. But the price tag was obscene and it wasn't something I'd be tempted to sell off what I have and make a move even at price parity.
This is for @PeterA:
I received this before the trip and today I cleaned and played it. I thought you might it enjoy it - on par with the Grumiaux:
This was in @zerostargeneral 's list from uk ebay. Hat tip to the general.
Cluytens is a fine Beethovenist. His Pastoral is my favorite.
I received this before the trip and today I cleaned and played it. I thought you might it enjoy it - on par with the Grumiaux:
This was in @zerostargeneral 's list from uk ebay. Hat tip to the general.
Cluytens is a fine Beethovenist. His Pastoral is my favorite.
Thank you for the recommendation, Tim. I saw that one but you snatched it up quickly. I will look for a copy.
What's this big platter turntable? How does it sound vs the AS-2000 and will it be released to the market (as a cheaper/more expensive/same price alternative to the AS-2000)?
Similar threads
