highly sensitive loudspeakers for single ended poe


Looking for a highly sensitive ( 94 plus DB) loudspeakers ( price range less than 10,000USD)
for single ended power amp. Any suggestion ?
fpooyandeh
        Sonist-Concerto 4's --97db spl, goes down into the high twenties. Simple first order crossover. I use them with 5 watts.
Good luck, TISH
Emerald Physics 2.8s have won TAS Award, and are on sale right now


Direct from Underwood HiFi
David12, the difference between 10 watts and 20 watts is 3 db. That's not a lot to the human ear- something else is going on.

SETs make very low distortion at low power levels. Once they get over about 25% of full power, then a substantial amount of harmonic distortion comes into play- including the odd ordered harmonics. Now music is composed of transients which consume most of the power, with less power in-between the transients (unless you listen to pipe organ). In addition, one of the most important human hearing rules is that the ear is uses the odd ordered harmonics to determine how loud a sound is.

The confluence of these two facts is that you have the loudness cues on the transients when using an SET that is being asked to make too much power (over about 25% of full power). This is why SETs have a reputation for being far more dynamic than their small power would suggest. If you get a sound pressure meter and actually measure how loud you are playing the system, it won't be all that loud, even though is *sounds* like it is loud, due to the artificial loudness cues.

IOW an SET running on a speaker of moderate efficiency (91 to 95 db or so) will sound louder than it really is. If you really want to hear what an SET can do, you simply have to have more speaker efficiency. In the old days (before my time, nice to say that for a change...) when SETs were the only game in town, *all* speakers were high efficiency.

Believe it or not, a stereo should not sound loud. IMO it is the mark of a good system that it remains relaxed at all volumes, even 105db or more. It should not drive you out of the room!

You may think you are doing OK with a lot of the moderate efficiency speakers mentioned, but you can be assured that you are not hearing the actual magic (inner detail) that SETs are capable of. I had ZU speakers for quite a long time, and have Classic Audio Loudspeakers now, both are about 98 db. I find that 60 watts is about right as it is nearly impossible to clip the amps. I have 2A3, type 45 and 300b amps; they can play the speakers certainly, but they fall right on their respective faces if I try to push them.

I will agree that there could be a listener preference going on; I like things to sound relaxed, but at the same time I play a lot of rock and electronic music that can be pretty demanding (I'm also a bit of a Wagner fan and some of the Decca-recorded operas are pretty demanding too).
WHT speakers look interesting and the US distributor is currently selling direct at substantial discounts - I presume, until he establishes a dealer network.

http://www.tmhaudio.com/
Another vote for Daedalus. I spent a lot of time looking for SET friendly speakers, but avoiding horns. I have'nt found a horn speaker, I could enjoy long term.

The 3 brands I realy enjoyed were Silverline Devore and Daedalus. The latter seemed the best in term of price, appearance and sound quality and my DA-RMa's run just fine with a 20 watt Ayon Spark. I am not sure a 10watt 300B, would be a great long term match.
I use a 300b SET with my Zu Def4s, and the sound fills my large space without any difficulty. It depends on the tube, the design of the SET, the output power, and many other factors including the room and (in my case) a very long run of speaker cable. If you are interested, you should call Zu to discuss. As I have learned, almost every SET is different and should not be lumped together. I had Def2s and tried 45 and 2a3 tubes before settling on 300b. Others swear by 845s. Other speaker considerations include the soon to be released Zu Druid 5, Audio Note, and Living Voice.
To get the best results out of an SET, unless its fairly high powered, the speaker should really not be less than about 97 db. Otherwise the amp will be making a lot of distortion, meaning that it will not sound as transparent and will also take on a harsher quality.

Typically efficiencies 10x higher than stated in prior posts (101 db to 109 db) are preferred- with these higher efficiencies the distortion of many SETs becomes unmeasurable.

This is why horn systems like Altec, JBL, Klipsch, Electro Voice and others have held their value so well. But in general, you want either a horn system or a high efficiency single-driver full range speaker like a Lowther, PHY or similar.

Now if you are in a small room the lessor efficiencies may work. As in many cases, YMMV.
I found Living Voice speakers to be extremely tube friendly and their sensitivity is 94db.
Granted, they're quite a bit under your budget, but they may work for you. The GoldenEar Triton Two towers have a rated sensitivity of 91 dB and are only $3K/pair. HOWEVER, they have built-in powered subwoofers and a single pair of speaker cables supplies signal to the whole thing. The most telling thing is that the designer/co-founder, Sandy Gross, co-founder of Polk and Definitive Technology, uses a SET to power his personal pair at home.

When you have 1200 wpc built-in to power the bass, you may find that 91 dB sensitivity for the rest of it will be enough.

Another possibility is the Zu Definition Mk IV. It also has a built-in powered sub, but sensitivity is spec'd at 101 dB and they're priced at $12,500/pair. However, the Definition Mk III is also in production, also has 101 dB rated sensitivity, built-in bass amp, and they're $7500/pair.

It's also my understanding that Zu structures their impedance curves to be friendly with low-powered SET amps.
The sensitivity rating is not the only thing to consider when matching a speaker to single ended amplifiers. The impedance, number of drivers and the complexity of the crossover are other major factors.
The Athena and DA-RMa models from Daedalus Audio I believe are within your price range (email them for current pricing), and meet your sensitivity criterion. All Daedalus models are highly regarded for their natural sonic character, their versatility with respect to amplifier selection, and their beautiful real wood construction, among other attributes.

Good luck in your search. Regards,
-- Al