"Bob-Stanton" wrote in message
om
"Arny Krueger" wrote in message news:bIKdnRc-

(1) I didn't say totally transparent, I said "more distortion" and
"more distortion free".

Two amplifiers, driven by an electronic crossover, are even more
distortion free yet. :-)

All you have to do is reduce distortion to the point where it is inaudible.
Easy enough to do in the 21st century - without active crossovers.

(2) At this point there is no formal definition of "low-priced"

How about under $200?

In terms of stand-alone power amps that does not leave a lot to select from.

Buying twice or three times as many power amps pretty well creams a
$800 system budget. Interestingly enough, a $800 system based on
better quality parts from the PC monitor or One Box Home Theater
market segment would probably end up with an active crossover.

Please see my 7/16 post about subwoofers.

Staying within an $800 budget is not tough.

Two, low cost, stereo amplifiers: $400
Passive electronic crossover: $ 20
Two Vifa woofers at $100 each: $200
Two Vifa TG 27 tweeters at $30 each: $ 60
Two old enclosures from a garage sale: $ 20

Total: $ 700

This isn't a system.

Well, at the cost of the extra amplifiers, which in a $800 total
system cost for a system assembled by a consumer, makes things
pretty tough.

3) Pick a woofer that is designed to work into a closed box. (Avoid
buying woofers that need to work into ported enclosures.)

????

Because making a ported enclosure work right, is more difficult than
just sticking a closed box driver, in the proper box.

IME, no. Either way, the best way is to optimize the driver & box
combination using Thiel/small parameters and verify with actual
measurements.

Most manufacturers of quality woofers provide T/S parameters and
leave the design up to the purchaser.

Manufactures give a "VB ltrs" spec. Isn't that the recommended box
volume?

Here's a sample set of data for a Vifa woofer from the manufacturer's web
site.

http://www.d-s-t.com/vifa/data/tc08sd49-04d.htm

Now maybe you can find Vb here, but I sure can't.

I can find Vas, but Vas isn't the same as recommended box size. Recommended
relationships between Vas, Vb and other parameters are given he

http://www.diysubwoofers.org/sld/sealed1.htm


Zoebels are for people who don't get it.

I'm one who doesn't "get it".

Zoebel networks convert the driver terminal impedance to a resistance.
That improves the crossover's rolloff characteristics. Zoebel's are
simple, cheap, and work darn well.

How do they relate to a system with an electronic crossover?


The price/performance and time investment is hard to beat.

Investing time, saves money.

Again, Rolling your own loudspeakers and getting good results is far from
simple unless you stick to subwoofers. Doing a two-way woofer/tweeter
speaker system *right* is actually one of the tougher technical chores
around.