RE: Re: 4ohm or 8ohm?

["Nikola Kasic" <nikola@xxxxxxx>]

Thanks Keith,
I thought about it, but what to do if I have only 3 of them, like now,
or 7 like I will end up with (I don't have 8th wire, maybe to speak in
node0 :-).
Can I just put 8ohm resistor in place of missing one?
I think that it's not that simple, because this impedance changes across
the frequency range or something like that.

Also, I'll have two of them different for bathroom (waterproof). What do
I need to put attention to when choosing those two, apart from being of
same impedance.
Do they have to be the same power rating?

Also, in this case of 8 speakers, how do I calculate power rating for
amplifier?
8x15W = 120W
Do I go then for 2x60W amp?

I'm a bit concerned about heating. Are those amplifiers generating heat
even in standby mode.
If I keep them on e.g. 50% volume all the time (I asume I have to if I
want them to be ready to play when signal comes to input), does that
mean that they'll consume the same power and generate the same heat,
wheather something is playing or not?

Sorry for so many questions, but the more I think about it, more
possible issues pop up.

Cheers,

Nik


-----Original Message-----
From: Keith Doxey [mailto:ukha@xxxxxxx]
Sent: 26 August 2003 11:00
To: ukha_d@xxxxxxx
Subject: RE: [ukha_d] Re: 4ohm or 8ohm?


Hi Nik

> -----Original Message-----
> From: Nikola Kasic [mailto:nikola@xxxxxxx]
>
> Now, when I have them installed (3 so far) how do I connect
> them all to the PC in node 0?
> Speakers are 15W(RMS)/30W(music power) each.
> And, eventually, I want to have 7 of them.

You really need to install 8 of them to make the wiring simple

Connect 2 8ohm speakers in series to give you 16 ohms.
Do the same with another pair to give you another 16 ohms
Connect the two series connected pairs to the output of one channel to
give
an effective load of 8 ohms which almost every amp shoud be totally
happy
with.

Do the same on the other channel with the other 4 speakers.

----- SPKR------SPKR----
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> Any pointers to small, suitable amp?
> I think that it should be fixed gain so volume is controlled by PC.
> Or any amplifier can be controlled that way?

Any amp is fixed gain.....

set the volume control to a position and dont touch it anymore :-)


Keith

www.diyha.co.uk
www.kat5.tv