Moving away from inefficient/low impedance speaker in order to move to a Tube Amp

I think this is talked about more on the amplifier side...tubes to solid state or vice versa. But as we all know, going with a  tube amp requires some effort in choosing the proper speaker. I have Harbeth C7's, which are a very nice speaker....but I'm not willing to spend the money on a high quality 100 watt tube amp. For those that have been in this scenario, please share some additional steps from your journey. Example 1: You had speaker A, but surprisingly found it worked fine with tubes...Example 2: You had speaker A, but it did not sing with tubes, so you found speaker B, and paired it with Tube amp C..... Cheers -Don


Although a speaker's sensitivity should be considered when matching them to an amplifier, it is wrong to use a speaker's sensitivity rating as an indication of quality. Many speaker designers opt to trade high sensitivity for deeper bass reproduction, especially in a smaller enclosure. Remember also that a tube powered amplifier will seem more powerful and play louder than a solid state amp of the same or similar power rating. 

Another way of calling loudspeaker efficiency/ sensitivity is: dynamic compression.

When the loudspeaker has no dynamic compression, it is capable of giving all the amplifier put out, then it translates to 100% efficiency which is 112dB/Wm.

An ultra-efficient 102dB/Wm is 10dB down from that, that is: it has a 10dB compression already. It's not just peak SPL drop! It's the dynamic range being compressed.

Thus, using 102dB/Wm loudspeaker is like adding a 10dB dynamic compressor to the music. The 92dB/Wm speaker adds a 20dB compression, and a 82dB/Wm speaker adds a whopping 30dB dynamic compression! Now, combine that with the compression that is applied to the recordings, and no wonder the playback sounds so lifeless!

The dynamic compression of the loudspeaker is the primary reason we can tell it's recorded music, not live.

Going for higher power does not restore compression, so a 82dB/Wm at 100W is not equal to 102dB/Wm at 1W, although both produce 102dB/m peak volume: yet the range is 20dB diminished for the 82dB loudspeaker vs the 102dB one.

If you feel that you are hitting a brick wall with your system development, then you can try going for more efficient speakers. Be warned - the higher the sensitivity, the more the system weak links are exposed. Go above 100dB/Wm, and the exposure of weak links is absolutely ruthless. The clothes of the emperor are revealed....






Mozartfan said: If you run a single FR, any tube amp will work just fine.

Could you tell me what FR means.

Thanks...the system will be a second floor bedroom, that is around 19 X 15, with standard 8 ft ceilings. Thus far I’ve owned a Luxman 550 AX/II, and it was pretty good, but nothing special. I think tubes are going to be a must for me. My main setup is Shindo/Altec, so perhaps I’m spoiled. I tried that Luxman with my Kuzma table, and it was still not as engaging as I would have liked.


The Audio Hungary (Qualiton) line has had my interest, so I appreciate the reminder. They remind me of Quicksilver in a way. Hand wired, no Circuit boards...not trying to reel customers in with hype or high price. Not to say you don’t get what you pay for, because sometimes you do. But I think we were in a very good place with tube amps 20 + years ago. Think VAC Renaissance...they were amazing. The old CJ premier series, Jadis...great OTL amps from Atmasphere, Tenor, Joule.... I don’t want to ramble....

On the positive side...we do have more efficient speakers to choose from today than we did 15 + years ago. 

I found a lot of the older speakers sound very good with 20 watts wpc. 

I've been running Macs and the last 4 years Carys with great success. I had one pair of 88db sensitivity @ 8 ohms speakers that used a quasi second order 4 way XO to help distribute the load. It was still a 6db first order bass section, with 2 12" drivers and a 12" passive radiator in a slot. That bass section hit 20 ohms. 

Guess what it pushed it like a champ by design. Amps like 20 ohms a whole lot better than 4 ohms. The weird thing is they sound really good to. Short heavy speaker ICs helped too. With a dampening of close to 100 @ 8 ohms. Not much between the amp and the driver (6db first order) but an inductor. The BIG 12" drivers are very well controlled with a Cary V12R and just 2 fat bottle 6L6 per channel. single ended at 20 watts or UL at 40. THEY ROCK. 95 db they are running out of gas.. LOL A MC275. That amp will run you out of the room.. Over 100db..

FR is full range or friggin' rummy take your pick.

That is Pope Mozartfan of the Wide Band. He really likes his speaker system..