Running 4 speakers from a 2-channel amp

Re;Series Hi Al,
In the 70' or 80's,a friend called me over upset about his stereo and asked me to come over,and I did.When I got there he showed me the new second pair of Infinity's(I believe)that he bought.He said he hooked them up together and must of blown something out.I told him I thought they were 4Ω ohm and his receiver couldn't drive two pairs most likely.The dealer told him it will work,and he had it playing at low volume when I arrived.He said the tweeters must have blown.I told him to turn the volume down and switch to one pair.When he did and turned it back up his eyes lit up.The highs were back.When switching both on you could here the volume drop.Right then I told him his receiver must be running them in series,and it sure enough was.On these crossover diagrams,figure 5 or 6 the highs that get though the choke coil are getting shorted out by C2 and C3 in these diagrams at least to my eyes.
Regards LINK>[http://www.termpro.com/articles/xover2.html]

Hello Mr H- The highs that pass through the inductor of a second, third or higher order filter, will be selectively shunted to ground via a cap, to increase the roll off to the woofer(and midrange, if applicable). The highs will be passed through the tweeter section of the crossover however, and still continue to the next system in the series. Of course, much of the energy in that frequency range will have been expended, in reproducing the highs/creating heat in that first system. Depending on the complexity, efficiency and reactance of the first system in a series circuit, there exists a large possibility/likelihood for seriously degraded sound, as your friend learned.

Hmm, actually HifiTime's statement about highs passing through the woofer crossover is more correct than I initially thought.

If speaker A is series connected to speaker B, the high frequency energy that manages to get through the inductor that is in series with the woofer of speaker A will not be shunted to ground via a cap, it will be shunted to speaker B through the cap. Where some fraction of that shunted signal will be reproduced in its full glory by the mid or high frequency driver of speaker B, complete with whatever distortions, phase effects, etc., were imposed on it by that inductor and capacitor in the woofer section of speaker A.

Figure 5 of the article HifiTime linked to in his previous post is helpful in visualizing this.

In any event, all three of us are in agreement on the bottom line -- for any of several reasons series connection is not a recipe for quality sound.

Regards,
-- Al

Thanks all you ppl for this insightful thread. I had initially thought it a simpler question...

The Bottom Line:

1.Respect Ohms Law!

2.Use a "real" power amplifier{one that Doubles Down)

3.Use accurate, sensitive, speakers that are 95db. min. @
8ohm.

4.Use quality cable at EVERY connection!

5.Respect Ohms Law!

Do the above, and I assure You, the sound you HEAR!

Will blow away what a single pair of ANY speaker!

Not the Infinity I.R.S. or the sister companies speakers,

that are 7' FEET TALL!

I am talking about smaller speakers that have a single

woofer, instead of 4 or 6 woofers in one cabinet, like

those "Super Speakers".

This is the whole IDEA! To create that same "SLAM!"

and "IMPACT!" that those 7' FOOT and taller speakers

are able to attain.

I assure You, few people have heard, and "FELT" what

an "array" of drivers can do with "UNLIMITED POWER!"

"SOUND" can be a very powerful, and devastating Force,

if ample speakers with Unlimited Power, are mated.

EVERY Hi-FI Person in Sales, ALL have told me, "You can't

do that?" But I do, and I HAVE, for 30 years+ without

ANY problems EVER!

They don't want you to achieve what they "can't SELL!"

LIES! LIES! LIES! ALL the B.S. saying "cancellation" and

all sorts of stupid "excuses", NONE of which, is TRUE!

When in doubt, TEST EVERYTHING!

Don't believe me, do it for yourself, THEN...

Insert "FOOT!" into mouth!

2 channel Stereo, 1 in front and 1 in the rear, with front

and rear center speakers, and side speakers.

Looped from 1 pre-amp to the 2nd, so volume is set for

front and rear to blend into a "Natural Surround" Sound.

I LOVE MUSIC!