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

All? Count me out.

Raven 20 watters are rec'd for less efficient speakers than yours.

Here they were preferred to a 300 wpc Mac.

Both tech ’s here in New Orleans, said ,,**You realize those are the wrong speakers for your Jadis Defy7 amp,,don’t you????...***

well not really.

Both are wrong.

And both have decades exp in this hobby.

fact of the matter was, the speakers were wrong choice for my music, not for the amp.

However,,,so I continued my speaker research,,hit on Full range, BINGO, found my solution to voicing my classical music.

The Seas Thors stay as assist.

So now I really need the Defy 100watts of pure power, to handle all the speaker load.

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

If you keep your old speakers readjust the xover, you will need a tube amp with some good trans.

At least 60 lbs of weight.

Hope that helps.

 

@fjn04 How big is the room in which this speaker is being used?

If you are planning a lower powered tube amp and need to fill a larger space, the Harbeths won’t do the job. They are 6 Ohms, and Sensitivity is rated 86dB, meaning their Efficiency is less: 85.5dB. That’s not quite criminally inefficient... This speaker might work fine for a bedroom system where high volume isn’t a requirement or in a smaller room, which are more common in Europe where this speaker was made.

I’d be looking at something like the ZU Audio loudspeakers, which are easy to drive and reasonably priced- also DeVore Fidelity, Audiokinesis, Spatial Audio (if you have the room they are nicely priced and good performers) or Pure Audio Project.

As a general rule of thumb all amplifiers regardless of their technology make higher distortion into lower impedances. If you want the system to sound relaxed and more realistic, for this simple reason lower impedance speakers should be avoided (high end is all about reducing colorations which distortion causes). Distortion can cause the system to be more strident- that alone is a good reason to seek higher impedance speakers!

Efficiency (1 watt/1 meter) is an easier spec to use than Sensitivity (2.83Volts/1 meter) if you are planning to use a tube amplifier. This is because tube amps do not double power as impedance is halved. So efficiency tells you sound pressure based on wattage; sensitivity tells you sound pressure based on voltage. So if you have a 90dB speaker (which might be a nice number) but its also 4 Ohms, 2.83 Volts into that load is 2 watts, not 1. That’s a 3dB difference, so that speaker would actually be only 87dB and you would need an amp with twice the power to make it play as loud as a speaker that was actually 90dB with 1 watt!

I bring this up because tube amplifier power is expensive- and it always has been, which is why back when tubes were the only game in town speakers tended to be a lot more efficient. You don’t want to spend the cash for a good 100 Watt amp and I don’t blame you. So the sort of speakers you want to be looking to will have efficiency ratings in the mid 90s- about 10dB more efficient than what you have now.

That will allow you to get the same volume with an amp with 1/10th the power. The speakers I mentioned do that, with no loss of resolution.

Getting good bass is harder as the efficiency of the speaker is increased- above 95dB it gets really expensive. You might want to look into a subwoofer system. The trick here is to keep the sub operating well below 80Hz- that way it will not attract attention to itself and you can get it to blend easily. But to get good bass at the listening chair you may well find that one sub has to be placed inconveniently. Two subs will help but the best way to do this is to run 4 subs. Since bass is entirely reverberant in most rooms below 80Hz (due to the length of the fundamental bass note; 80Hz is 14 feet) or so, they can be run with a mono signal. Audiokinesis makes a sub system called the Swarm which is reasonably priced and designed to be placed directly against the wall. You might contact Duke about them. This would allow the main speakers to be smaller.

Audiokinesis

 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. 

How much do you want to spend? What preamp are you using?

I had a 35 wpc Primaluna amp.  Got the low watt bug and bought a Decware Mini Torii 4wpc amp.  Kept my Ref 3A speakers ( rated at 92db eff.)

 

Other than not being able to bother the neighbors I got plenty of sound in a 12x20ft room open on the long sides.

Wouldn't mind a more efficient speaker but haven't seen one the trips my ticket.

 

Have a Grommes PHI-26 6 wpc speaker in a second system with 97db Klipsch Quartets  both sound great just different

 

We had some monitors like that here, they were a similar 87dB and with my 20W Raven Blackhawk had no problem driving them satisfyingly loud in my 17x24x9 room. The guy who brought them had also brought his 100+ watt SS amp. We were all surprised how those inefficient power hogs came alive with the Blackhawk.

It is good you are figuring out something I have used as a speaker buying guide all my life- avoid low sensitivity speakers, they limit you on amps. But unless your room is huge or you rock out a lot (not likely, Harbeth after all) then you will be fine with any tube amp 20W or more.

As a general rule of thumb all amplifiers regardless of their technology make higher distortion into lower impedances.

       Agreed!

 

Have not done it but done a lot of research investigating the possibilities. Class D amps have kept me from having to go there (tube amps) to-date.

Not in general interested in large bulky speakers required for best performance in general with low watt tube amps.

However, to test the waters on a limited budget, I would likely go with Klipsch Heritage line and pick a tube amp from there. Could be Heresy, Forte, or Cornwall depending on specific room and what would provide the most flexibility there. Would also consider Spatial Audio in the right room or Fritz speakers (easy load to drive) for something more compact. I would also probably at first be inclined to give it a go with my existing Ohm Walsh speakers, but would expect to need at least 20 watts or so or more.

With a limited budget, practically, it would be hard to talk myself out of trying this

Amazon.com: Willsenton R8 KT88/EL34 x4 Tube Integrated AMP Power Amplifier Headphone (Silver) : Electronics

as a first stab. Lots of good reviews, good build quality, flexible, value.

Beyond that, if needed, on a grander budget, amps I have heard that I would strongly consider come from companies like Audio Research, Rogue, Jolida/Black Ice, Conrad Johnson, Linear Tube Audio, Audio Note and I’m sure several others.

 

 

 

Harbeth while not efficient I believe have an easy impedance curve for tubes. I think you would be fine with 20 watts or so. 

I just picked up a Jolida 302crc with very upgraded preamp and power tubes and it sounds very powerful on my Focals. No lack of power whatsoever. I believe it's rated around 40 watts per channel. This is also my first EL34 tube amp and I was expecting weak bass. NOT the case at all. I would not call it tight exactly but big and not too flabby. On the other hand snare drums that used to be just a snare sound now have a certain tactile feel to them. It's been a while since I have had tubes and I'm diggin it. Long term tbd.   

why not try one of the better reviewed Chinese tube amps some of them are quite good and you can get 50-100wpc easily. Willsenton R8 for example is quite good for the money and very well built. made in the same factory as primaluna etc. 

 

another option is vintage or older tube amps as the tech has not really change much in the last few decades other than refinements. There's a ton of quality use tube amps that will give you more power to drive your speakers and give you more head room. 

some examples: current adds here. 

Line Magnetic 211IA | Tube | Detroit, Michigan 48214 | Audiogon 35wpc

Black Ice Audio F22 50wpc balanced integrated tube amp | Tube | Bluff City, Tennessee 37618 | Audiogon 60wpc

VAC Avatar Super Stereo Integrated Tube Amplifier; MM Phono; Remote (35148) | Tube | Erie, Colorado 80516 | Audiogon

VTL IT-85 | Tube | Houston, Texas 77069 | Audiogon

I have an Audio Hungary Qualiton X200 matched with QLN Prestige 5 and it is audio heaven. I have owned several Ravens and would not recommend for a speaker below 92 db. As a matter of fact the best match for the Raven Blackhawk is their CeLest speakers they are great speakers, James is a excellent speaker designer and they have a gem.

 

Focal speakers have above 92db models. And they are pretty decent speakers. 

Right now I drive 948s with Single Ended amplifier

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..

Regards

My Omegas rock with very few watts. Worth a gander. 

I have no need for inefficient amps that double as room heaters. Try the fabulous AGD amps, they look like tubes, they sound like tubes, they drive any speaker. They consume less energy, save you money, tubes don’t wear out. They even glow orange! To me, the future.

 

I think it is a matter of finding the right speaker and then matching them with the proper amplification.  Even if the the speakers are supposedly not efficient enough to work well with lower-powered amps, I personally find that, in most instances they can be made to work with modestly powered tube amps.  I find that most people grossly over estimate the amount of power they need or try to achieve rock concert volume level even though the speakers and the room itself are ill-equipped for such practices.  Every choice is a set of compromises and I personally choose to go with very high quality at modest listening levels, and every improvement I make tends to make the sound enjoyable at lower, not higher, volume levels.

If you like the Harbeth speakers you have, I don't see how you can save money by getting another speaker of higher efficiency and then looking for a lower powered amp.  The really good sounding low powered amps are NOT cheaper just because they deliver lower power.  High power these days is cheap to achieve, quality at all levels of power is not. 

My local Harbeth dealer sells only tube amplifiers, and most of them, including the best sounding ones, are low powered.  The only Harbeth model that seems to benefit from higher power is the 40.2, and even they sounded their best with particularly good lower-powered amps (but played at decent, but not extremely loud levels).  

It has been said over and over on hundreds of posts. It is the old horse power vs torque argument in engines. Watts per channel is only a small factor in the overall power of an amp. You can buy an amp with 500 wats per channel that has no power and you can buy an amp with 5 watts per channel that has tons of power. Do the research and reach out to the companies to break down the amps total package and specs. In todays world you might even be able to contact the designer and ask them to define your solution.

I used Primaluna 36 watts to drive 88bd Salk Songtowers with great ease.Then traded up to 70watt Primaluna Evo 400 and found it didn't really make much difference in the ability to drive the Salks but sounded better.

Then I bought 93bd Tannoy Turnberry GR and that made a big difference in detail. All these subtleties came through.Will never again buy a speaker of even average efficiency.

 

Thanks...the system will be a second floor bedroom, that is around 19 X 15, with standard 8 ft ceilings.

In a bedroom system your speakers will be fine if you have the space unless you really plan to blast. I would think an amp with 15-20 watts would be plenty. You might want to add a sub just to handle 50Hz and down.

If you get something like the ZU Omens I would expect that in a bedroom you could do well with an amp of only 5 watts per channel.

Bedrooms for the most part simply don't need to play all that loud.

I have read over and over again how important it is to purchase high efficient speakers.  Why bog things down with a low impedance speaker?

 

I wonder what people think of either then Revel Performa's and the Paradigm Persona 3 speakers?  I did prefer the Revel's.  No one ever talks about these speakers.  Wonder why?

Why bog things down with a low impedance speaker?

In a bedroom system it won't matter so much.

I have McIntosh MC30s driving 4ohm Sonus Faber Venere S’s. No problems

I have a pair of Klipschorns in my main system and a pair of  16 Ohms Zu Soul Superfly's in my secondary system.

Both pairs absolutely sing with a tiny 3.5W Miniwatt N3 amp.

The amp has 4,6 and 8 Ohm taps on the rear of the transformers but I have only ever used the 8 Ohms taps.

My Luxman 25 watt tube amps running a horn speaker with 2 x 21" woofers speakers are 4 ohms 103db 1 watt.

jerryg123: Are you running your Qualiton X200 with KT 88, 120, or KT 150’s. Really nice setup, but your Prestige speaker is out of my price range for my second system. I bet they are wonderful though. Ralph...I think you’re right in that this bedroom system isn’t really for playing at loud levels. For a source, I may start out simple with a BlueSound Node to get things going. That would be my first streamer.

While I am impressed with the Klipsch Heritage line of speakers driven by tube amps... I'm equally impressed by the Harbeth line of speakers driven by the type of amps their designer (Alan Shaw) suggests drive them best - high powered SS amps, which best control their drivers (Hegel in particular)!  

I drive my Harbeths with the Hegel H590, but the other Hegel amps drive them equally well (H390 in particular)... and... they seem to be driven very well by the McIntosh MA252 or MA352 (tube/ss hybrids)!

If... you... don't want to totally disrupt your system.

I'm driving my Forte IV with 40 watts of EL34 power in a smallish to medium room and its plenty of power .   It was plenty of power for my Revel M106 too as long as you didn't want to crank it too loud.  Not the best pairing but sounded great at normal to moderately loud levels 

I am having a 300b built and 8 watts should be plenty for my system and listening habits 

Folks seem to forget one very important factor when choosing an amp, tube or ss, and that is the quality and ability of the transformer. This, IMO, has more to do with the drive capability than just about anything else. The amount of watts/ch is secondary to this aspect. This is the reason that a lot of well built lower powered tube amps with great transformers can sound as loud, or louder, than a much higher output ss device with a wimpy transformer, as an example.

i suppose IF ya think of mechanical amplifiers aka compression driver / horn and cone breakup as not lossy, a bit of uniform compression ain't the devil you think it is…

For those seeking stunningly well designed and executed output transformers look no further than Gow’s MC240 or Roger Modjeski RM-9. 40 wpc and 100+ WPC….

BTW, heard an absolutely gorgeous sounding pair of Harbeth w Line Magnetic low powered amp the other day at Gig Harbor Audio….

Cast a wide net ;-)

 

 

+++ @daveyf right you are, BOTH ( or more ) transformers…power supply , output…and ? 

Ok my 2 cents ,I own Polk lsim707, 8 ohm 88 eff..The manual saids 20 to 300 watts to drive them.But everyone who has tested these speakers say ,you will need 300 to 350 watts to drive them.I had used a SS amps Adcom,Carver,and others to drive them.Then one day I hooked up my Cayin A 50 TP MK 11 tube integrated amp to drive them...I used the ultralinrar sett5at 35 wpc.and have found no problem driving them...I have a nice size livingroom 28x32 with Cathedral ceilings...ok I dont put the volume up like I'm in a concert hall,put they play loud.Every article I have read saids ,you need power to drive them...the tubes do a great job and they sound great.

fjn04 OP

1,468 posts

11-23-2021 8:32pm

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

Could you tell me what FR means.

 

 

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Yeah well read realworldaudio posts above, What he is saying is that xover type speakers are under 90 db sens = lots of compression = the lower db you go the more IN-Efficient = more work on the amplifier = less fidelity = crappy sound.

I’ve completely moved away from xover types.

Even if Scanspeak and Seas did make a 90++ sens drivers and Troels put something together,, still we have the xover point to deal with.

= Double flawed.

Low sens + xover point = unmusical.

The sound is stressed/compressed/attacking/just plain noisey.

FR = Full range,, The DITers want to keep it FR, not *wide banders*

 

Here is a smaple of the performance of a higher sens FR speaker in action, 95db sens.

If you go SET, the magic can only come forth witha magical speaker.

SET’s require a high fidelity speaker.;

As realworldaudio noted

 

**A high sens FR/horn that has issues will be cleanly noted in a SET amp set up...** The higher the sens, the more will any weakness be noted in the speakers performance.

 

Resonances, fq spikes, shouts, muddyiness, bloatedness,, too forward a mid range at sacrifice of bass,,,,lets not forget beaming which some Tang band suffers from.

 

I did say just about any tube amp will work ok witha FR.

But the end results are not the same.

SET amps are great for low key recordings,, for big band jazz/blues,  large band.orchestra, PP wins the Cuban Cigar.

I attempt to explain some of these things in this video.

Horns work great with SETs for that massive soundstage for extra large rooms, For a more intimate listening exp for small/mid size rooms, FR work best

 

https://www.youtube.com/watch?v=4XTmQHjF0e4

 

 

Speakers are a very important component. I would put the sound of the speakers above all. It is pretty easy to evaluate speakers and just check to see they are not really inefficient. You want speakers you love the sound of, then tweak your electronics to get to most out of them. So, just stay away from planar and <87db or so. 

One of the greatest changes I made to my system was going from solid state amps to tubed. While I have less than half the power, no question my system sounds the best it ever has… although to be honest, while the wattage halved, the cost did double… so probably not surprising it sounds so much better. 
 

As an owner of Altecs you probably know that exquisite midrange is not a trait exclusive to Harbeth. Many speakers in that price range are equals or better than the C7s in that regard, so no good reason to limit your amp choice to those unless you’re absolutely smitten by them. I would personally want a speaker that has far greater dynamic range, i.e. one that can wake up at low volumes but also play loud without obvious compression. The C7s can do neither IME.

Definitely consider the Spatials if your space allows. The Seas A26 is good if you don’t mind a little DIY.