How to accurately gauge speaker sensitivity to match with tube amp?
I'm in the process of matching speakers to my amplifier and need a bit of advice. Most recently, I'm trying Focal 936 towers with my Quicksilver Mono 60w amp. They were sounding pretty decent until I experimented by hooking up my old Adcom 535L amp. All of a sudden, there was a giant jump in control, tautness in the bass, quickness in transients. The QS stuff was doing quite decently, but the Adcom really snapped these towers to attention. The mids and high ends, not to mention the soundstage, were worse with the Adcom — no question. But there was quite a difference with the other qualities just mentioned.
My question becomes one of sensitivity. The Focals self-rated as 92 db. Stereophile rated them as 89.5db. I realize that these are average measurements and a much bigger picture is told by the impedance graph (and other factors).
As I continue to search for the right match of speaker (I have a couple contenders), I'm sure one piece of advice is to look for speakers with higher sensitivity averages. But what else should I look for to help make a guesstimate about whether the amp will drive the speakers with the kind of control they are capable of? [Specs for this amp are here: http://quicksilveraudio.com/products/sixty-watt-mono-amp/ ]
I realize I need to hear speakers, in my house, with my gear, etc. to get a sense of them. I’m working in exactly this way. Your advice can help me eliminate candidate speakers that would pose similar challenges to my amp as these Focals have.
And I just bought the amp, so I don't want to change it.
Thank you for any thoughts.
P.S. Anyone who has has had great success with this amp or similar, please shout it out.
Of course, this presupposes that the speakers you've become interested in have been measured reliably and that an impedance curve has been published. Fritz's standmounts do very well with low-powered tubes (I heard them with a Modwright SET headphone amp!!) but I'm not aware of published curves for the various models. |
http://www.fritzspeakers.com/DreamWeaverFritzImpedancePage.aspAnd a bunch of comparative measurements. |
For a change of pace, try ProAc DT8. Full tested specs here. https://planethifi.com/proac-response-dt8/#Impedance_and_electric_phase Not as accommodating as the Fritz, but still recommended for use with tubes from 25W up. For years I drove the ProAc Response 2.5s with a 12W 300B SET amp. The modern "D" series needs more juice, though, but not the DTs. |
Yes, the Nighthawk's specs are 20 watts per channel: (8Ω, 1% THD). If you follow John Atkinson's measurements in Stereophile, he often has to allow higher levels of distortion, e.g. 3%, to get a tested tube amp to achieve its manufacturer-specified output. The amp will put out more than 20W but as almarg says with increasing levels of distortion. |
