Advice on speakers for Home Cinema rcvr...
 

In article ,
wrote:

I've just bought a couple of Home Cinema receivers in the sales.
Need help understanding speaker watts.

Teac AGH550
Spec shown he http://www.homeaudiosuperstore.com/product460.html

This is a 5.1 unit. It has 5 independent audio amps that produce
up to 80 watts each. This includes a front right, front left,
center, rear right, and rear left. The subwoofer output is is
at line level, so the sub needs its own amplifier.

RX-V730RDS Home Cinema Receiver
Spec shown he
http://www.yamaha-audio.co.uk/homeci...0rds/index.asp

This is a 6.1 unit. It has 6 independent audio amps that produce
up to 75 watts each. They are the same as above, but with the
addition of a rear center channel.

I can't understand the meaning of ohms at all, tried looking at
various webpages with diagrams but it still doesn't make any sense.

As long as you connect a single speaker to a single output on the
back of the receiver, you can all but ignore ohms. All modern
hi-fi and home theater speakers are in the 4 to 10 ohm range, and
all amps can drive one of them per amplifier.

From what I can gather, most speakers and systems use 8ohms and if you
go lower than 4 it starts to get dangerous, risking damaging the amp??

As long as you go one speaker per amp, this basically true.

I think this means you can't put loads of speakers on the amp
otherwise you'll put too much stress on it. My AV receiver has wires
for the individual speakers (6.1) so 1 speaker gets plugged into 1
port. I guess I don't need to worry about ohms when buying speakers??

When you want to connect more than one speaker per amplifier, you
have to follow the laws of parallel and series speakers. For
example, if you want to connect two 8-ohm speaker, put them in
parallel to get 4-ohms, which these amps can drive OK. If you want
4 speakers, put two in parallel, then the other two in parallel,
and finally these two groups of parallel speakers in series. The
parallel groups each make 4-ohms, but by putting two groups in
series, you are back up to 8-ohms.

Also, I need help understanding speaker power in W's.

The RX-V730RDS Home Cinema Receiver is rated 125 W per speaker.

That number is when loaded at 4 ohms. The legitimate method of
rating power is based on 8-ohms. Use the 75-watt number, it is
more accurate of a representation.

My amp is rated 125w per channel, if i buy speakers that are rated
150w, 200w or 250w per speaker, will I lose out on the quaility?
Should I *only* be buying 125w rated speakers for the 125w amp?

Speaker power ratings are mostly foo-foo numbers, and are their
for marketing. They are supposed to mean the maximum amount of
power that the speaker can tollerate. In reality, even low levels
of dirty power can damage a speaker, and some speakers can handle
very high levels of clean power.

and for the Teac AGH550, it is rated at 80w per channel, does this
mean I should *only* buy 80w speakers? If I put 100w or 150w speakers
on the Teac, will it make any difference to quality?

Some (but not all) speakers have a range printed on the back for
example like 60w to 90w, others just have 90w.

In general, you can ignore the power ratings. You do want speakers
that can handle more power than what your amp can produce, but then
again, few people listen at extrememly high power levels. Even a
single watt of power going to your speakers is going to produce
ear-splitting volumes on reasonably efficient speakers when used
in home applications.

It is far more important to get speakers that sound good.

-john-

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John A. Weeks III 952-432-2708
Newave Communications http://www.johnweeks.com
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