@nakam
20wpc is good for 96db @ 3.5m w 91db 2.83V/8Ω/1m speakers
Plenty loud.
Speaker impedance may change the above somewhat
20wpc is good for 96db @ 3.5m w 91db 2.83V/8Ω/1m speakers
Plenty loud.
Speaker impedance may change the above somewhat
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.
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- 85 posts total
@almarg So the tweeter getting to hot from excess energy would cause failure? If occasional mild clipping wouldn't cause any damage, how easily would it be to detect mild clipping in LF leaking into the HF area of the tweeter? Could this type of clipping be easier to not notice in lower powered tube amps causing not occasional clipping but a lot? |
To add to my previous posts on this subject, an illustration of what a clipped waveform looks like: https://www.mtx.com/i/mtxcom/clipped-signal.jpg As you can see it alternates (going both positive and negative), as does the original signal of course. So it is not DC, which the series capacitor that is commonly part of the high-pass section of a speaker’s crossover network would block from reaching the tweeter even if it were. +Vcc and -Vcc shown in the figure represent the maximum positive and negative output voltages the amp can provide into the particular speaker load. Also, note the sharp discontinuity between the smoothly rising or falling parts of the waveform and the flat top and bottom. The frequency components corresponding to that sharp discontinuity contain the excess high frequency energy I referred to. (Examining the clipped waveform with a spectrum analyzer, which indicates the various frequency components of the signal, would show that). Most of that excess energy will tend to be routed to the tweeter by the crossover network, since it is at high frequencies. Regards, -- Al |
- 85 posts total