Audiophiles/engineers

[flatbutt]

I have a new low end home theatre with surround sound. The speakers are absolute crap. I want to replace them and they are 8 ohm speakers. Is that the only requirement I need to concern myself with? Buy 6speakers at 8 ohms regardless of the cone size? I would only be getting bookshelf size anyway.

[Chocaholic]

Lots more to consider besides impedance. How about sensitivity? If you have a "crap" system...adding better speakers to a "crap" source component will likely be a waste of money. If you buy 86 db/watt speakers with a flea-sized amp, you won't acheive the volume necessary for decent home theater....and sound quality will still be "crap".

Unless you're going to upgrade your entire system, don't waste money on another set of speakers.

[flatbutt]

Amp RMS 167 Watts per channel 1Khz 8 ohms but the subwoofer is 100 Hz 8 ohms

Freq response 200 Hz +/- 3 dB

Does that help any?

[island911]

They really need to be 168 Watts per channel , else they are pure crap. (kidding)

[Gogar]

If you're asking:

"If buying new speakers, is 8 ohms the only thing I have to -worry- about, safety wise?"

Then, YES, you'll be fine. Consumer-level speakers in the store will almost exclusively be 8 ohms anyway, no prob.

When folks chime in about the other things, they're just trying to explain that speakers aren't everything. Kind of like this:

Speakers = tires.
Amp = engine.

speakers can only be as good as the electronics that are backing them up. The same way that you only really worry about the quality of your tires if you can EXCEED the quality of your tires with your engine, etc.

[RANDY P]

Pretty much everything in bookshelf is 8ohm -

Impedence will affect your overall output assuming similar sensitivity levels between drivers. lower impedence is like having a lighter car, which allows the amplifier to work harder (less resistance)-

Of course, this could overload the amp because it's passing too much power and getting hot.

back to topic, I'd look for a speaker with a relatively high sensitivity rating, if you have cheap speakers now they probably have high ratings- higher quality speakers although the impedence matches if they aren't as sensitive as what you have now they will seem subjectively quieter...

The moral of the story, match the impedence and look for a relatively sensitive speaker- have the sales guy steer you in the right direction.

rjp

[RANDY P]

I used to build car audio systems that ran under 1 ohm consistently. Loads of fun

[javadog]

I'd suggest that you get a book on home theaters and read up about it. Way more to know than I care to type. The choice of speakers, and their placement, is pretty important, as are the physical characteristics of the room that you put them in. You may have decent results, you may not. It may be the speakers, it may be the room... Small speakers aren't going to do much for you in a home theater, even in a good room. Your expectations may need adjusting.

Good luck,
JR

[imcarthur]

Originally Posted by flatbutt

Amp RMS 167 Watts per channel 1Khz 8 ohms but the subwoofer is 100 Hz 8 ohms

Freq response 200 Hz +/- 3 dB

Does that help any?

No. What receiver do you have? A rating at 1kHz is virtually useless. But the make & model will give us a clue.

As above, an economically balanced system is what is important. For HT, the 3 front speakers - Center + left & right are the most important. Dialogue & music tracks. Then comes the sub which is important for impact. Then the surrounds.

A small decent 5.1 sub-sat system can give you pleasing realistic results.



Ian