[Walt]

Bret Ludwig wrote:

Damon Seeley wrote:

I am producing an installation that features multi-channel audio in a
museum space. The cavity that I have for installing the 8 speakers is
only 3" deep. I have had trouble finding home speakers that can fit in
this cavity, and thus began thinking about small auto speakers in
custom boxes.

I am not after super high-quality sound but I would like it to sound
good in the mid and high ranges. The whole setup would work as
follows:

1 computer with multi-channel audio card puts out 8 unbalanced signals
to...
4 cheap stereo ampifiers, which power...
2 small 4" 4ohm auto speakers per channel on each amplifier, for a
total of...
8 channels and 16 speakers of multi-channel audio.

Any suggestions on how to do this better while not spending tons of $$$
on multichannel pro amps? Thanks for any advice you have!

As was said earlier you should not connect individual multiway
crossed-over systems in series with a single source. You should
determine the suitability of your amplifier for use with 4 ohm loads
and if it is not suitable another amp is in order. In a museum
application how much continuous audio power will you be running??
Probably it will work fine.


Well, he wants to connect two speakers to each amp channel, so that
would mean 2 ohms not four if he were to wire them in parallel.

Your concerns regarding shifting crossover points with series-wired
boxen are well taken, but I'd say given the rest of the information that
that would be the way to go. It will work, and sound OK - we used to do
this with JBL control 1's for theater near fills back in the day. In
any case, nothing's going to burn up if he wires the speakers in series.

The watchword here is "inexpensive" - you can pick up used home
receivers for $20 to $30, so specing out something more
robust/professional than that is probably a non-starter.

So, Damon, wire the car speakers in series, two to an amp channel.
It'll work fine. Alternatively, use 8 ohm speakers and wire them in
parallel for total load of 4 ohms. Trying to run two four ohm speakers
in parallel i.e. a two ohm load is pushing it for home stereo gear.

Since you're installing them in a small cavity, a car speaker should
work as well as anything else. Try to get a good seal around the speaker
and place some acoustic deadening material in the cavity - the idea is
to kill off (absorb) the energy coming off the back of the speaker -
that'll greatly improve your bass response.

Your main limiting factors sound-quality wise is probably the quality of
the speakers themselves. Good luck.

//Walt