Speaker suitability for valve amps....

[eddieedwards]

I'm getting a bit of an itch and might look to change speakers in the coming months/ year. I've been looking around for speaker to partner well with my Leben and something has got me questioning exactly what to look for when searching for a good match (I'll obviously listen first, and that's all that matters really!).

You often hear it said that "x" speakers are voiced for valves, or these "y" speakers only work well with solid state, but why is that? For example, Harbeth is often stated to be a good match for Leben/ valves, yet are only rated at 86db, ATC is also similarly sensitive yet are mainly viewed as solid state suitable, whilst others might be more sensitive, yet primarily recommended for solid state.

So what actually makes a speaker suitable or not, as it clearly isn't just sensitivity and impedance - does it relate to physical characteristics too then?

[Sherwood]

My Rogers LS35a speakers work well with valves as do two other speakers I own. My Reference 3a De Capo are high efficiency speakers and operate without a cross-over. My Omega Marathon is also a high efficiency speaker that uses a single Alnico driver. Depending on where you are in Derbyshire you might want to bring your Leben over if you wanted to hear them in the flesh.

[eddieedwards]

My Rogers LS35a speakers work well with valves as do two other speakers I own. My Reference 3a De Capo are high efficiency speakers and operate without a cross-over. My Omega Marathon is also a high efficiency speaker that uses a single Alnico driver. Depending on where you are in Derbyshire you might want to bring your Leben over if you wanted to hear them in the flesh.

Thank you Geoff, that's a very kind offer.

I suppose I'm asking why are some speakers considered valve friendly, or solid state preferable, when they appear to be similarly specced in terms of impedance and sensitivity? There must be more to it than meets the (non technical) eye!

[Sherwood]

I find that low impedance designs do not fare so well with valves. As a general rule, higher efficiency designs work well but my LS35a speakers are 15ohm and relatively inefficient and they are an excellent match to my valve amplifier.

[struth]

Depends on the output transformer, and thus the reflected load back. Turns ratio etc... sure one of our resident geniuss will have better info.

[Sherwood]

Depends on the output transformer, and thus the reflected load back. Turns ratio etc... sure one of our resident geniuss will have better info.

Clearly not all valves are created (or designed) equal. My first valve amplifier was a Rogers Cadet 3. Whilst this was not special in any way and relatively low powered, to my ear it sounded much better driving my Rogers LS35a speakers than my Rogers A75 ss amplifier.

[Bonky]

"Living Voice" speakers are recognised to work well with valve amps (and Sugden amps).

[Arkless Electronics]

Thank you Geoff, that's a very kind offer.

I suppose I'm asking why are some speakers considered valve friendly, or solid state preferable, when they appear to be similarly specced in terms of impedance and sensitivity? There must be more to it than meets the (non technical) eye!

Indeed there is... Much depends on what the valve amp is. Big push pull ones with plenty of feedback can be expected to drive pretty much anything ok. Examples are the likes of EAR 509, 519, Radford STA100, Papworth M100 and several Audio Research and Mcintosh amps. IE the more SS like measuring ones with plenty of power. At the other extreme are the likes of SET's with often only 8-15WPC output and a high output impedance. The lack of power obviously requires high efficiency speakers in order to get the required volume from so little power. The high output impedance means a poor damping factor (to over simplify a little, the ability to "grip" the speaker cone), which means speakers with good "self damping" properties are best. The high output impedance also means that the frequency response will tend to try and follow the impedance curve of the speaker so speakers with a fairly flat impedance are best.

Between such extreme examples are the many 15-30WPC mainly push pull amps with moderate feedback. As you would imagine speaker requirements are a bit more relaxed than for an SET, of course it could easily drive any SET friendly speaker, but would also handle ones with a bit lower efficiency and rather more awkward load. In this category are so many different models that, well, it's gonna have to be down to those sound detectors on the sides of your head!

[RothwellAudio]

It helps if the impedance curve is fairly flat, and also the phase curve. Actually, the two are closely linked anyway.
Also, it makes a difference how loud you like to listen and to what kind of music. Taking a low powered valve amp and trying to play Metallica at Metallica gig volumes would most likely result in disappointment. However, that doesn't mean you wouldn't enjoy other types of music at lower volumes.

[Macca]

We had Steve (Bourney's) Leben sounding magnificent through some JBLs at MiBO but I can't recall what model they were now, except they were '4' series three way stand mounts. Might not be too easy to locate some for sale though.