Efficient, affordable speakers for SETs?

I, mostly, disagree with this statement. Regarding amp/speaker, one cannot say that a high powered amp is not designed to supply the juice needed for high sound output. And that a large speaker system is not designed similarly?
Another point is that I do believe, especially limiting the low frequency output of my 90db flat 8 ohm Tetra 506s with a good Rel sub gives me "the most" out of speakers. Taken into consideration that the voicing of the speakers was with 8 watts of 300B. I do understand that a 100db+ speaker is an entirely different story from a physical/tech perspective.
Surely, an Ocellia is not a "Rock and Roll" speaker and is more suited to the dynamics of Jazz. Is it not greatly contingent on a speaker's physicality?
Just a personal note to you, maybe 30+ years ago I called you thinking of buying one of your amps to power my Quad 57s. You graciously turned me away saying that my then Bedini 15/15 was a great amp for the 57s. A quite belated thanks!

@mglik At the time I was under the impression that the old Quads were a too variable load for our amps. Boy did that turn out to be wrong! One of my employees had the 57s and it turned out they worked great with our amps- as long as you were careful to not overpower the speaker.

Your opening comment in the quote above doesn't seem to address my comment- which was only that its impossible to build a high fidelity component to favor a certain genre. What makes a component good at one genre will make it good for another- whether that is classical, jazz, rock, metal or ethnic folk.


While the Tetra may have been 'voiced' on an SET (whatever that means) the simple fact is that even with a sub, unless you are in a smaller room 8 watts would not be enough power. If that's what you are running, you might want to try a more powerful tube amp- perhaps a push-pull amp with about 30-60 watts, since the speaker appears very tube-friendly. You may find they wake up in a good way you did not expect!

I had some experience with PHY drivers. The Ocellia speaker uses them and is very sensitive but not dynamic enough. Audio Note UK are an industry standard for decades but their output is also somewhat limited. The Ocellia and AN seem good for classical and Jazz.

@mglik FWIW its impossible to design any hifi audio product to favor a certain genre of music. We did have a pair of Ocellias here and I personally found them to be way too colored due to cabinet resonance. However the drivers themselves are quite good and as dynamic as any high efficiency 'full range' drivers.

There’s also a somewhat hidden corollary, here, which is that I ended up multiplying my error by saddling a low power / high output impedance amplifier with a 12” or 15” woofer.

@jim_hodgson If the speaker is designed to work with amps of high output impedance then no worries driving larger speaker cones at all. IMO that is one of the bigger myths around SETs and large cone speakers. Our amplifiers have similar output impedance to SETs, and have no worries with the dual 15" woofers in the Classic Audio Loudspeakers (which are 97dB). The impedance usually plays a far bigger role!

If you're so dead set on running an SET amp, then the only real answer is the K-horn.

I would regard this as inaccurate to say the least. JBL made many speakers, amongst them the Hartsfield, which have similar efficiency. The Hartsfields were designed for corner operation (although the reproductions made by Classic Audio Loudspeakers seem to work quite well when not placed in corners). When I was in college I had a set of Altec corner horns; there are also things like the AvantGardes and many others in high end audio. But it is this kind of efficiency (+100dB) that you really want to be looking for if you want the most out of an SET. You're not going to get there with higher powered SETs as the demands of the output transformer design are prodigious; the price you pay for increased power is reduced bandwidth, to the point where in most cases the term 'hifi' can't be used.

PHY has introduced a new 6" driver that is inexpensive, 96dB and 16 ohms. Duke of Audiokinesis designed a sealed box for it; we're listening to a prototype of it which is very fast and images effortlessly. The driver is also suitable for OB or quarter wave rear loaded horn applications (there are plans for the quarter wave horn cabinet on the PHY website). Duke told me he was impressed at how smooth the driver is; it has no whizzer cone but goes past 15KHz rivaling the best full range drivers. It can go down below 80Hz so can be easily integrated with a sub (80Hz is sort of the magic number in that regard; below 80Hz bass is omnidirectional to the human ear so even though the sub might be elsewhere, the bass will sound as if its coming from the main speakers due to harmonics of the bass notes).


Although this is a bit on the low side for efficiency for most SETs, if the SET didn't have to play anything below 80Hz this could be quite practical.

@stereo5  Sandy is also one of our customers and has an S-30, which he uses on his Quads. BTW his Subx subs are quite good.

I’ve owned Vandersteen 1B speakers for a long time.They are easy to drive and have a 6 ohm impedance.

These are not suitable for an SET. Generally speaking, to get the best out of any SET the amplifier should never be driven past about 20-25% of full power. If you do, higher ordered harmonics begin to appear, at first only on transients. The ear uses those harmonics to sense sound pressure, so this causes the amp to sound very 'dynamic' but its really distortion masquerading as dynamics. If you've read about how dynamic SETs can be, this is why. A speaker at least 10dB more efficient that the Vandersteens is needed; even the Coincidents are a bit on the low side, notwithstanding the fact that they also sell SETs.


One way to deal with this is to get a sub or subs (the best being the Audiokinesis Swarm) and then get a speaker that only goes down to 70Hz or so. If the SET does not have to make the bass and the speaker doesn't either, the choices available goes up quite a lot!