Amp matching with high sensitivity speakers


I sold a pair of B&W 803 D2’s and went the polar opposite with a pair of minty Chorus 1’s I bought from a friend. I have mixed feelings about the move so far but have new Crites Crossovers and Ti diaphragms in hand and will be installing as soon as I can find a couple of hours. Perhaps that will improve detail and dynamics a bit. One of the reasons for picking up the Chorus is trying the high sensitivity speaker/lower watt amp combo that many audiophiles enjoy.  

I came across a post from Klipsch recommending to use no less than 80% and no more than twice the speaker’s continuous power rating. The RMS on the Chorus is 100 watts. I could be wrong but take that to mean use an amp no less than 80 watts and I more than 200 watts. The article talks about potentially damaging the speakers with too low or too much power. https://support.klipsch.com/hc/en-us/articles/360044125891-Choosing-the-Right-Receiver-Amplifier

I’m looking for feedback on those actually using lower watt amps on this 80% rule for speakers. I’m using a 300 watt Levinson 532H but eager to try a lower power tube or a First Watt solid state as soon as possible. Thanks for chiming in. 

Ag insider logo xs@2xbfoura

Thanks @Mulveling for the explanation! That could explain some hum concerns I experience when moving interconnects and components in and out. The gain for the Levinson is 26db. The gain from my Audible Illusions L3A is 30dB which seems quite a bit more than you recommend. I have a Herron preamp with two gain options: one at around 14 and the other at about 8dB. I’m going to move the Herron back in to see how everything reacts. Today I installed a Cardas blue sky phono interconnect to replace the stock one in my table and a hum is there when I turn up Tyne volume a bit. I wish there was a book or similar to find out more about all this electronic component matching you detail. 

There’s no problem driving them with your 300 Watt amp, just be careful with the volume control. Again, your ears will bleed before the speakers are in danger.

I have 96 dB / 2.83V Tannoys, and I’ve definitely noticed that noise floor is something to be mindful of. Any power amp by itself, whether tube or SS, should not render audible hiss or hum. The problem is that the amp’s gain will magnify your preamp’s noise floor (from active circuity after the volume control). So the more gain your amp has, the lower you need the preamp’s noise floor to be. Active preamps with a higher gain tend to have higher noise floor, unless their signal-to-noise ratio is also higher. Tube preamps with high gains (> 14dB) are usually asking for trouble. I can really hear the noise floor of many preamps in my system.

The ARC Reference 6 has an extremely high signal to noise ratio, so despite its relatively high 14dB gain, it’s dead quiet in my system. Most other tube preamps, I can hear varying degrees of hiss noise with the volume at 0 (not muted).

In modern times, a SS amp will have higher gain in order to facilitate tapping into a very high power rating (you need a lot of gain to push out say 400+ Watts). However, a lot of the lower powered tubes amps will have a surprisingly high gain because using a 12ax7 V1 tube was popular, and analog sources of that era had low output levels so the extra gain was welcomed (for example: the Eico HF-87 tube amp required a meager 0.38V input to produce full rated power of 35 Watts!). So even when you go to lower power tube amps, it may have similar gain to your much more powerful SS amp. This means you should be very careful if you’re selecting a tube preamp to pair with it, or you will hear its hissssss noise!

 

Sounds like I have some options for amps for these speakers, which is what I was hoping for. I will say things don’t sound of out whack with my 300 watt Levinson, which many would consider over kill for these speakers but it’s what I have right now. 

Would going with an all tube system introduce more hum or blackground noise with high sensitivity speakers? I have a tube pre and phono and curious about that. Or, would a high watt amp like my Levinson contribute to background noise as well? 

 

I hate to extrapolate, but my experience with lower output amps (35, 70, 80, 150 watt) with JBL 4367s (94db/hybrid with 15" woofers) was not good. Sure, they will play loud, but the bass is soft, creating great discontinuity between the horn's and woofer's respective frequency range. Obviously there are speakers without crossovers that sound fantastic with tiny amps. One is Voxativ's Zeth at 95db. I have come to the conclusion that the sensitivity is not the beginning and end of amplifier output choice.     

I agree that Klipsch, for that matter any brand or model, cannot represent horn-system sound.  The other issue is that high efficiency speakers are particularly sensitive to the amplifier being use, but most people never hear such speakers with optimal amplification (typically, high quality tube amplification).

Klipsch is fine to try out higher sensitivity but it's near equal to dipping a toe in a hot tub. So if this combo is not to your liking don't judge all higher sensitivity loudspeakers saying you explored them you just tried a wee taste of what they can do.

good rule of thumb, but things get a little bit more complicated with high sensitivity full range drivers (don‘t they always) as this article by Nelson Pass will explain:

https://www.firstwatt.com/pdf/art_cs_amps.pdf

 

The dramping factor of your amplifier and how that equates to an overal system damping factor inc the impedance of speaker cables can also become part of the equation, usually higher DF the better.

you won‘t actually damage the speakers with a single ended 300B tube amp unless you are a complete bonehead. They soft clip and sound so flabby and out of control when right over the limit you won‘t want to be listening to them.

I can’t speak for those who play speakers at extremely loud levels.  If I had speakers as efficient as yours, I would not rule out amps rated as low as 5 watts per channel.  This brings into play low-powered tube amps (my favorite kind of amp), or some low-powered solid state amps, like those offered by First Watt (Pass Labs offshoot).

The thing with tube amps is that it is very hard to find a good one for really low prices because the cost of decent output transformers alone can be quite high. Used amps can keep the price down and are a good option with tube gear because even very old amps tend to be serviceable (many solid state amps are harder to repair because they tend to be more complicated and have parts that become unobtainable).

With speakers of this high efficiency, I would be looking at tube amps running EL 84’s, 6L6, KT 66 (pentode/tetrode pushpull amps), or single-ended triode amps.  Because of their simplicity, some might expect single-ended triode amps to be inexpensive, the demands placed on the output transformer means that decent amps can be quite high in price.  The cheapest decent one that I know of is a 300B amp from Elekit (you save a lot because it is a kit that has to assembled), but the other issue is that the 300B tube can be quite high in price.

 

sensitiviity is only part of the equatio - impedance and the way impedance changes over the frequency range also matter. Some tube amps only like medium to high impedance speakers.

tKlipsch stated sensitivitiess are notoriously optomistic BTW. Not knocking them, but good to know. Really the only way to know how any given amp is going to react to a speaker is to tey it. I have heard some quite unlikely pairings sound good and vice versa.

The speaker specs you want to know is the sensitivity and freq range . In theory the higher the sensitivity, the lower the wattage needed. . I run a Bob Latino ST 70 (Dynaco clone) with a 93.5 Sensitivity speaker and it sounds great.  I liked it enough to buy it's custom made Big Brother, Don Sachs Kootenay 120. These are tube amps with one rated 35 wpc, the other 65wpc.

The smaller of the 2, about $1500 complete. Bob's ST 120 $1800. Great amp 

Hey @carlsbad, I would like to find a low cost, low

powered to experiment with and appreciate you suggesting the Sophia Baby Tube amp. Do you know if it has a line level input? I need to have a remote and if I can hook my preamp to it that would work. Thanks @mulveling for

the explanation. Speaker technicals are not my forte and what you’re saying makes sense to me. It makes sense to me that underpowered amps would work with high sensitivity amps but should I be concerned about using a 300 watt amp with these speakers? Cause of my living environment I can’t play too loud. Everything has sounded fine with the Levinson but wonder if moving down a few watts will help protect the speakers and perhaps provide better sound. 

You’ll be fine. Unlike most audiophile speaker makers, Klipsch also has to serve the Bud Light party bros and home theater nuts who will absolutely THRASH their speakers at absurd volume levels. That warning and its very conservative amp power recommendation is intended for them, not you and I - proper 2ch audiophiles 😉

The risk with clipping from too little power is specific to the tweeters, which are normally designed & spec’d to handle MUCH LESS peak and continuous power than woofers. The tweeters are protected by a high-pass crossover plus the fact that most power in musical content resides in the lower frequencies. However at instances of hard clipping (especially with SS amps), the clipped content has peaks which measure at TWICE the max continuous power rating of your amp and at very high frequencies to boot. This effectively goes right through the high-pass filter (because it’s comprised of high frequencies, even if for a very short instant) and sends these power peaks directly into the tweeter. That’s bad, and this is why clipping is considered a tweeter killer. It also sounds like SH*T and hurts your ears badly because high frequency content at such high levels is extremely unnatural.

But the reality is that your 100+ dB speakers will make your ears bleed long before you hit hard clipping with any amp north of say 10 Watts. Also, if you choose a tube amp or a single (which is more likely at lower power classes), it will naturally soften the clipping a bit, which reduces the peak power sent into tweeters. Also the First Watt amps, being class A without much (if any) global negative feedback, should likewise feature more gradual clipping (I think). So I wouldn’t worry about it!

I'm definitely in the low watt amp/high sensitivity speaker camp.  I don't know if you're looking at tubes but that is certainly a popular option and the one I like.  I googled your speakers and my speakers are 96 dB just like yours. 

I am currently driving them with a Sophia Baby tube amp that I picked up on ebay as an interim solution while waiting for my new amp (Ayon Spark Delta, 35 wpc).  

Unless you have a huge room and like to blast your ears, the Sophia is more than enough.  I've never had it turned up even close all the way.  It is extremely detailed, transparent, and imaging.  I've seen one for sale lately for $550 or so and I would highly recommend it as an amp to play around with while you do your research and since you are questioning if this is the right way to go, its a very inexpensive way to hear the capabilities of this type of system.   Frankly, if the Sophia had a remote and a pre-in connection, I might not even upgrade it.  I've compared it to $5k ss amps and it wasn't even close.

Jerry