8 ohm for 16 ohm speaker in Workgroup Server 9150

ClassicHasClass

Active Tinkerer
Aug 30, 2022
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I expect this is the same for the Quadra 900/950 and AWS 95, since they all use the same speaker assembly as far as I can tell.

My 9150's onboard speaker has crapped out (this machine just finds new ways to break every day). I've confirmed it's the speaker by getting another 16 ohm and plugging it in, and there is audio. The board was professionally recapped by the almighty @Garrett and works well.

The speaker assembly is part #630-6011, which appears to be a 4" diametre 16 ohm 3W. It's pretty difficult finding an exact replacement for this and most used Mac speakers from other systems, although they match the impedance, are smaller and may not take as many watts.

Amazon has a 4" 8 ohm 5W for a few bucks. I am not great with speakers, but my understanding is that an 8 ohm would pull double the current, and I do not know enough about the output stage on these to know if that would stress the amplifier. Am I overthinking this?
 

Certificate of Excellence

Active Tinkerer
Nov 1, 2021
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If I couldn’t find the right speaker I think I’d try a 5w rated 8ohm resistor in series with the 8ohm speaker which would present a 16ohm load the power amp is looking for. You’d get a drop in volume technically because you’re cutting everything in half (3w to 1.5w) but in human ear terms I don’t think you’d notice too much.

Anyways if you can’t find a suitable replacement, that might work for you.