Damping Factor Solid State&Tube

[flintstone mop]

Hello
About a year or so ago there was a very interesting article in Radio World about the magical match between a speaker system and the amplifier. It is extremely critical the mating process of a particular speaker to the driving amplifier. I read some speaker system will not sound as designed if driven by a tube amplifier and the typical low damping factor that tube amps have compared to the really high damping factor that a solid state amp will have.
The article explains what has to be considered to obtain the sound the listener wants to hear. Some speaker systems needed more current to get them going and hence would not sound good driven by a tube amplifier. Tubes had a nice velvety high end and a 40 watt amplifier had enough ooomph to fill the room with a pleasent sound BUT if you wanted to have chest pounding bass the solid state will amp will always shine if the right match was made during the time of purchase. I still have a wonderful pair of JBL 4400's and a 200 watt/channel amp was needed to move those cones and make a very powerful sound. They sounded best suspended from the ceiling and flat against the wall. On the floor was a totally strange and disapointing sound.
Could some one please give me a possible link to this info?
Thanks
Fred

[WBear2GCR]

Fred,

I don't have a specific site to point to. Suggest a search on "damping factor" & "frequency response" might turn up some info.

The general theme of what you said is approximately correct.

However, the final "Q" of the system is what will determine the subjective sound and the measured frequency response wrt the bass section. Above the bass frequencies there is less observable difference - assuming tube amps with feedback are what we are comparing to.

So, if the final Q of the system is 0.707 it makes no real difference if it is arrived at via a woofer box with higher Q and a high DF amp, or if it is a woofer box with lower Q and a low DF amp!

Some (rather odd ones) designs rely upon a very low DF amp to achieve reasonable bass response. Imho, not a great idea.

Relative pounding, is just that - relative.

Where you hear differences with little difficulty is when for example a high Q woofer box is mated to a low DF amp - the result being an underdamped bass. Or in the converse case, where a low Q woofer box is mated to a high DF amp, the result then being a very over damped bass.

In the case of non-feedback (ZFB) tube amps, then impedance variations anywhere in the speaker's range will cause frequency response differences.

Fyi, the DF of a ZFB amp with an 8 ohm output fed into an 8 ohm load, DF = 1.
I think the Crown MacroReference amp has a DF of 60,000??

Fwiw, some tube amps have awful highs, imho, as do some solid state amps. The converse is true and has more to do with design (accidental or intentional) than with the devices employed. But yes, there are some differences inherent in the harmonics produced by tubes vs. the harmonics produced by solid state devices.

           _-_-bear