Could a speaker attenuator substitute for a preamp


I have four speakers. A pair of Klipschorns in the front corners and a pair of LaScalas in the center. I have one stereo amplifier, and one preamplifier to power and control all four speakers. The left channel signal goes to one K-horn and one LaScala. The same goes for the right side.In order to control the K-horns separately from the LaScalas, I will need another stereo amplifier, and another preamplifier. However, I could make small independent changes in all of the speakers by using post amplifier step attenuators at each speaker. I heard that post amplifier volume controls are a no-no. Are there any post amplifier step attenuators that are as good as class "AA" preamplifiers? I hoping that I won't have to buy another amplifier and preamplifier.
redwoodgarden
The problem with using *speaker* level controls is that they go between the amp and the speaker and are an impedance. This means that your damping factor will be one (DF = 1).
In the case of your Klipsh, that might be an advantage, but probably not - it will make your bass subjectively "looser"
than if it was hooked directly to a solid state amp.

IF you were using a ZERO feedback tube amp to drive your speakers, your DF would also be very close to 1.

You are probably presenting a very wierd load to your amp now anyhow with the K horns wired in parallel to the La Scalas - so you'd likely get better results without that lash up.

I'd strongly suggest some tube amps for that rig, since the top ends of both speakers (imho) need all the smoothing you can manage...

Depending upon the vintage of your K-horns (older being better) if I owned them, I'd a) put polypropylene caps into
the xover, b) put a decent tweeter horn into the top slot of both speakers and c) if you don't have the old deep throat
(long length) mid horns, find some! I'd change the coils too
for newer lower DCR types...

Besides, with two Khorns, I'm unclear on why you need two
"center" speakers at all - unless the K horns are only for
the bass?

If you are using the center speakers for "fill" they should be down a number of dB anyhow (quite a few) - so perhaps you *can* get away with a fixed L pad to drop them down in level, as a guestimate about 10dB or so. I would make the input resistance of the pad out of fixed power resistors and make it a little *high* in value - like 16 ohms - so that the overall impedance of your total load will still not be too much lower than the nominal 8 ohms of the K-horns...

Since the center speakers would then be down a lot of dB, you'll mostly be tickling them, and the woofers will not contribute quite so much, and the DF issue might not be so noticeable.

Actually, the best thing is to look up the old "dynaco" matrix connections, and use that for the center drive (you'll only need one speaker).

But the best solution is a small tube amp for the center channel(s) regardless... as long as you keep the levels down, you don't need much power with the efficiency of those
La Scala speakers...

_-_-bear

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