Feb 9th, 2015
Q) Hi some time back I purchased a pair of Electro-Voice Interface A speakers on E-bay less the equalizer. I hooked them up and they sounded fine but I seem to remember them having more bass response (I am basing this on how I remember them sounding 30 or so years ago). I finally saw another one on E-bay again last week or so but lost the bid, I have two questions: first, do you feel this unit is required for the speakers to perform correctly (it seems like it but I would like another opinion). Second if so how do I go about purchasing this item from you? I realize that you could spin a good yarn about all the benefits of this unit and how the speakers just aren’t the same without it, but after reading some of your comments on this web site I feel I am dealing with someone who will at least be honest.
A) Concerning EV Interface A speakers – In the era which these were designed, they were one of the better passive, resonant radiator design, whereby the motion of an 8 inch woofer induces resonant (sympathetic resonance) into a passive (no magnet on the woofer) radiator. Obviously now it requires a more powerful woofer and a magnet structure to provide this power. The whole box system has it’s funny resonances. Passive radiator systems are prone to many different false tuning resonances due to how hard the woofer is driven and what complicated frequencies in the extreme deep bass will affect the radiators performance. It’s all very tricky, and certainly to use an optimized equalizer to attempt to correct the deep bass response becomes a need but not absolute requirement. By today’s standard, woofers are cleaner and more efficient than the EV. EV tweeters are limited in performance too. It’s a fairly cheap paper tweeter, but does the right tonal balance. All in all, it’s an interesting and pleasing speaker, but inaccurate and a troublesome electro-mechanical load. A good amplifier must be used.
Usually we install a superior tweeter and crossover, more carefully install optimized cabinet dampening, and the speakers are much more real. Presently they are entertaining sounding, but don’t reproduce any of the nuance (real bass definition and spatial imaging) with complex music. Still, they do have a likeable sound which I admittedly sell to vintage audiophiles who like a thick and veiled resolution sound. Again it was certainly one of the better designs in it’s day, but in no way could be considered true hi fidelity.
Indeed the equalizer box is needed to make this design have the effect intended. It is a phase shift equalizer optimized to correct the extreme deep bass response. It has a few settings “big, bigger and biggest bass”.
Thanks
-Vince
p.s. if you have any more questions feel free to give a call, and yes, we do tell it like it is, thanks for appreciating that.