[lcrim]

It occurred to me after seeing JohnR's post that if there is a downside to High Efficiency speakers  and I mean over 100 dB (like Horns) then it could be that you need pretty quiet electronics which gets pricey because true HE reveals all the noise and everything else in the system.  I doubt if my amps, as much as I like them would be a good fit in such an environment because they are just not quiet enough.

[DVV]

It occurred to me after seeing JohnR's post that if there is a downside to High Efficiency speakers  and I mean over 100 dB (like Horns) then it could be that you need pretty quiet electronics which gets pricey because true HE reveals all the noise and everything else in the system.  I doubt if my amps, as much as I like them would be a good fit in such an environment because they are just not quiet enough.

All of which is food for some thought. In my experience, tube gear is usually quite behind solid state in signal-to-noise ratios. So, using a low powered SET with high efficiency speakers should highlight that shortcoming rather than hide it.

For years, I have never once heard any SET fan complain about noise being a problem - until it was brought up in this thread.

Having no personal experience, I must ask - has anyone here PRACTICAL experience with this issue that he could share with us?

Cheers,
DVV

[doug s.]

All of which is food for some thought. In my experience, tube gear is usually quite behind solid state in signal-to-noise ratios. So, using a low powered SET with high efficiency speakers should highlight that shortcoming rather than hide it.

For years, I have never once heard any SET fan complain about noise being a problem - until it was brought up in this thread.

Having no personal experience, I must ask - has anyone here PRACTICAL experience with this issue that he could share with us?

Cheers,
DVV

again, my present speakers are only 97db-efficient.  but, only one amp out of several i have used, is in any way noisy.  not noisy enuff to be a problem, imo, but others mite disagree.  in any event, i think it's much easier/cheaper to find good quiet amps for HE speakers than it is to find good powerful amps for LE speakers, at least if yure looking at tubed amps.  likely true for s/s amps as well, but it's not as cut-n-dry...

my opinion of course,

doug s.

[brj]

For those that consider low efficiency designs to inherantly suffer a dynamics penalty, I would recommend looking at an active setup.

By using an active crossover and individual amps for each driver, the amps can then be much, much smaller - and therefore potentially faster - because they are directly feeding only one driver, which is in turn handling only a subset of the entire frequency range.  In addition, by putting the amps after the crossover, you don't have the crossover network absorbing power, and the damping factor for each amp is now uniform at the amp's maximum value across the entire frequency range of the connected driver.  There are no passive crossover induced impedance variations.  For a 3 way speaker, for example, you've electrically just created 3 single driver speakers.

Active systems tend to be known for their dynamics.

(Note that while an assumption of "larger = slower" and "smaller = faster" might reflect a general tendancy, I would never rely on that assumption to dictate which amps to dismiss without an audition.)

[Scott F.]

All of which is food for some thought. In my experience, tube gear is usually quite behind solid state in signal-to-noise ratios. So, using a low powered SET with high efficiency speakers should highlight that shortcoming rather than hide it.

For years, I have never once heard any SET fan complain about noise being a problem - until it was brought up in this thread.

Having no personal experience, I must ask - has anyone here PRACTICAL experience with this issue that he could share with us?

Cheers,
DVV

I use Lowthers in the Medallion cabinets (about 101dB) along with 15" Goodman SK-111's as subs (about 102dB). I'm fortunate, my Korato pre, SET for the Lowhters and PP amps I use for the sub are all pretty quiet.  

Thats not to say they don't transmit audible noise through the HE speakers but to me, it's completely acceptable. You literally have to be standing with your ear to the speakers to hear it. It isn't audible at the listening position (11' away).

What absolutely drives me nuts in my system are the dimmer switches I have in my house. Unfortunately, tubes (typically) don't have quite the same power supply filtering as solid state gear (obviously). When you compare my measley 500uF of power supply capacitance to say Klaus' Odyssey amps at 100,000uF, well lets just say it's no wonder I can hear all the crap that rides the mains.

Is noise an issue? Yes and no. It's all about compromises. I favor what the SET/HE over even my big tubed PP/LE does. In turn I choose to live with the SET/HE drawbacks (even though they to me are minor).

It's sort of like favoring the sound of vinyl over CDs. With vinyl you tend to listen around the pops and clicks of dust to find a place that is completely comfortable, musically.

[lcrim]

There are certainly plenty of SET amps that have a high signal to noise ratio.  The cost of those amps is relatively high in comparison to those that I own.
My point was that as efficiency of the speaker gets higher, one needs to consider the noise floor of your system.  We were discussing the downside in using HE speakers and I think there is a point at which lower power, not necessarily lower quality electronics which make intelligent tradeoffs can provide great value.  I feel that I have found a few examples of that, there are certainly others.  If my speakers were of higher efficiency that value might be lost --- a possible downside to HE speakers.