@audiokinesis
Darn it, you beat me to it :) We had the same thought…
Darn it, you beat me to it :) We had the same thought…
Speaker impedance patterns - how to read them?
I know this has probably been discussed ad nauseam, but here's my question. I'm grateful for any sensible opinion.
Premise.
A speaker system may have a complex impedance pattern that can vary from 3-ohms to 30-ohms depending on frequency. Some speaker systems with similar impedance patterns may be stated as being 8-ohm loads because the speaker is 8 ohm in an important part of its frequency response, but only there.
A tube amp, as a voltage amplifier, likes a regular impedance pattern. Almost no speaker system has a constant, regular impedance pattern. I am aware that solid state, powerful amps are built to compensate for modern speakers' complex impedance patterns, but there are tube amps around and people who love them. It's difficult to understand what average load a given speaker system will present to the amp.
Question.
When looking for suitable speakers for a tube amp - mine is a PrimaLuna EVO 100, 40w x 2 from EL34s - what must be looked at? How to best interpret the impedance pattern, whenever available? Assuming that one listens at normal levels in a medium-sized room, what are the criteria for matching speaker and amp?
Thanks for your views. M.
Premise.
A speaker system may have a complex impedance pattern that can vary from 3-ohms to 30-ohms depending on frequency. Some speaker systems with similar impedance patterns may be stated as being 8-ohm loads because the speaker is 8 ohm in an important part of its frequency response, but only there.
A tube amp, as a voltage amplifier, likes a regular impedance pattern. Almost no speaker system has a constant, regular impedance pattern. I am aware that solid state, powerful amps are built to compensate for modern speakers' complex impedance patterns, but there are tube amps around and people who love them. It's difficult to understand what average load a given speaker system will present to the amp.
Question.
When looking for suitable speakers for a tube amp - mine is a PrimaLuna EVO 100, 40w x 2 from EL34s - what must be looked at? How to best interpret the impedance pattern, whenever available? Assuming that one listens at normal levels in a medium-sized room, what are the criteria for matching speaker and amp?
Thanks for your views. M.
Showing 3 responses by perkri
@timlub Last I checked, the 57’s are indeed a loudspeaker. And they have an impedance curve. Brought them up because of the demanding impedance curve they present to an amp. They are a good point of discussion when dealing with amp/loudspeaker matching. The amp needs to deal with peaks and dips properly. So as not to over drive the low impedance, and under drive the high. pretty simple. |
Your drivers impedance will peak at its resonant frequency. Enclosure (size and type) and crossover (not simply the crossover point, but the design of the circuit) will both have a direct effect on the impedance curve of the speaker. Amplifiers (some) like to see an easy load. My ESL-57’s do not present an easy load, and are fussy when it comes to the type of power supplied. Ralph sent me this link in my thread on the ESL57’s. Found it to be extremely helpful. http://www.atma-sphere.com/en/resources-paradigms-in-amplifier-design.html |