Blown Speaker Replacement Thread

[ahurst]

If you've spent a lot of time with old Apple gear, chances are you've had the bittersweet experience of hearing an old iMac or PowerMac whirr to life with a muffled, scratchy chime played through a blown or rotten speaker. The fix a decade ago would be to just find a replacement speaker on eBay and swap it in, but given that spare parts for PowerPC Macs are getting harder to find (and are increasingly more likely to be rotting or blown themselves), I think it's worth looking into (and nicely documenting) some DIY options.

I've already seen threads and videos about replacing rotten speakers in the iMac G3 with cheap replacement drivers, but I haven't seen any similar information for iMac G4s and PowerMacs. Somehow the speakers on my slot-loading iMac G3 are fine, but the internal speakers in my iMac G4 and B&W G3 are a distorted mess!

Anyway, my idea is to pull our collective knowledge and hardware together to document the sizes, wattages, and impedances of all the internal (and external) Apple speakers used across the PowerPC lineup so that we can then try to findsuitable aftermarket replacements. Once we've pooled some knowledge, I'll make this a proper WikiPost with a table of speaker specs per product family, links to community-recommended replacements, and links to corresponding community replacement guides.

Here's what I've got so far:

Model	Size	Wattage	Impedance
Power Mac G3 (B&W)	70 x 40mm	2W	8 Ohms
Power Mac G4 (Digital Audio)	70 x 40mm	2W	8 Ohms
iMac G3 (Slot-loading)	28mm diameter (?)	4W (?)	4 Ohms (?)
Apple Pro Speakers	57mm diameter, 35mm depth	10W	?

I'm not 100% about the iMac G3 numbers since they're based off of various guides and posts I found online. The PowerMac G3 and G4 I verified myself. For the PowerMacs, the closest I've found to a drop-in replacement are these 70mm x 40mm speakers that are 5W, 8 Ohms. I don't know enough about speakers to know how much of a problem the Wattage mismatch is, though.

Let me know if you've got numbers to share for any other models!

 

[Certificate of Excellence]

Lower watt speaker 2w to higher watt speaker 5w is no problem - in this instance you're just increasing the theoretical powerhandling ceiling of the speaker. The power section will still output the 2w it is designed to. It is critical however to match the impedance. Swapping to a speaker with a higher Impediance rating (lower ohm number ie: 8ohm to 2ohm) will drive the power section harder because of the increased resistance causing power amplifier damage. The reverse scenario will drive the speaker too hard causing audio clipping and speaker/driver damage.

Neat thread idea

 

[ahurst]

Lower watt speaker 2w to higher watt speaker 5w is no problem - in this instance you're just increasing the theoretical powerhandling ceiling of the speaker. The power section will still output the 2w it is designed to. It is critical however to match the impedance. Swapping to a speaker with a higher Impediance rating (lower ohm number ie: 8ohm to 2ohm) will drive the power section harder because of the increased resistance causing power amplifier damage. The reverse scenario will drive the speaker too hard causing audio clipping and speaker/driver damage.

Neat thread idea

Thanks! That helps a lot. I'm going to try ordering the linked 70 x 40mm speakers and see how well they work. They certainly can't be worse than the speakers they're replacing.

Really hoping someone knows the details for the iMac G4 speaker so I don't have to take mine apart again. It's a wonderful design on the outside, but the tight packaging makes the internals a huge pain to get at!

 

[Certificate of Excellence]

Although I have two sets of pro speakers (one for an imacg4 and one for powermacg4) I don't see any official specs listed on them. I had a set of the powermac pro speakers with the long leads that suffered from the microbial foam rot & have them apart for reconing so I was able to take some measurements. I do know that they are 10w output each. Their dimensions look to be w57mm x h35mm, & the driver looks to be 25mm in diameter. In regards to ohms, I ran across some old early 2k forums where folks said they were 4ohms but this was just their words, no supporting documentation or links. In that conversation it was unclear if they were 4oh each, in series? Parallel etc.? so am unsure about what that meant exactly. My multi meter died so when I pick a new one up, I’ll check their resistance reading.

 

[ahurst]

Although I have two sets of pro speakers (one for an imacg4 and one for powermacg4) I don't see any official specs listed on them. I had a set of the powermac pro speakers with the long leads that suffered from the microbial foam rot & have them apart for reconing so I was able to take some measurements. I do know that they are 10w output each. Their dimensions look to be w57mm x h35mm, & the driver looks to be 25mm in diameter. In regards to ohms, I ran across some old early 2k forums where folks said they were 4ohms but this was just their words, no supporting documentation or links. In that conversation it was unclear if they were 4oh each, in series? Parallel etc.? so am unsure about what that meant exactly. My multi meter died so when I pick a new one up, I’ll check their resistance reading.

Amazing, thanks! I've added the basic information to the first post. Also, nice Commodore CRT.

Can you explain a bit about what the re-coning process involves? If it's replacing the rotted foam while preserving the rest of the speaker, where do you find the replacement foam? That sound like a promising option for the iMac G4 internal speaker as well.

 

[TheShortTimer]

View attachment 1993903

Off-topic indulgence, is that a Commodore 1701/2 in the background?

 

[Certificate of Excellence]

Although I have two sets of pro speakers (one for an imacg4 and one for powermacg4) I don't see any specs listed on them. I do know that they are 10w output each and the

Off-topic indulgence, is that a Commodore 1701/2 in the background?

Yessir it is! Bit of a C64 love nestled inbetween my PowerPC macs and early Intel DDs.

 

[Certificate of Excellence]

Amazing, thanks! I've added the basic information to the first post. Also, nice Commodore CRT.

Can you explain a bit about what the re-coning process involves? If it's replacing the rotted foam while preserving the rest of the speaker, where do you find the replacement foam? That sound like a promising option for the iMac G4 internal speaker as well.

Yeah, I remove the rotted foam bits (which is a tedious PITA) and clean the sticky goo left behind with a solvent. Unfortunately, the solvent removes the white finish, but dems da breaks. I could repaint them afterwards if I was so inclined to do so. The replacement speaker surrounds are these:

2" 2inch 2 inch 55mm Speaker Surround Rubber Woofer Edge Audio Repair | eBay

Center the surround evenly as you place it on cone. Re-glue gasket to outer surround. After you report any problem wait for our answer.

www.ebay.com

although I have yet to get them (still out there somewhere) hopefully in the coming weeks. I also noticed these drivers which seem like they would be pretty close to a drop in replacement for these acrylic Balls of Fury. Haven't tried them myself yet so am unsure how they sound but are a fair price I think for the set.

2pcs JBL Harman Kardon 2 inch full range speaker | eBay

Find many great new & used options and get the best deals for 2pcs JBL Harman Kardon 2 inch full range speaker at the best online prices at eBay! Free shipping for many products!

www.ebay.com

To adhere them, I use an adhesive that dries flexible. There are many including actual speaker glues which are handy because of their thin applicator tip, but iirc last time I repaired speaker damage, I used a loctite variant I had in the garage and a toothpick to apply it and it worked out fine. Still, if I was spending money, I'd look at adhesives with a fine applicator tip & medium viscosity. It just makes it alot easier to get a consistent and small bead where you need it.

 

[B S Magnet]

Off-topic indulgence, is that a Commodore 1701/2 in the background?

Hey, I was about to ask the very same!

I had a 1701 as a kid which was matched to a C64, and later, as an adult, a friend gave me the 1701 they’d been using for years as a door weight. After a dozen or so years, I finally let that one go on CL in 2011 during my last intercity move (to lighten up my personal possessions load). It still worked as well as the original one I used to have, but aside from connecting my clamshell iBook or point-and-shoot Fujifilm camera from 2007, I didn’t have much of a use for it.

Their CRTs was excellent in their day. I have no idea which company manufactured the CRT itself.

 

[B S Magnet]

If you've spent a lot of time with old Apple gear, chances are you've had the bittersweet experience of hearing an old iMac or PowerMac whirr to life with a muffled, scratchy chime played through a blown or rotten speaker. The fix a decade ago would be to just find a replacement speaker on eBay and swap it in, but given that spare parts for PowerPC Macs are getting harder to find (and are increasingly more likely to be rotting or blown themselves), I think it's worth looking into (and nicely documenting) some DIY options.

I've already seen threads and videos about replacing rotten speakers in the iMac G3 with cheap replacement drivers, but I haven't seen any similar information for iMac G4s and PowerMacs. Somehow the speakers on my slot-loading iMac G3 are fine, but the internal speakers in my iMac G4 and B&W G3 are a distorted mess!

Anyway, my idea is to pull our collective knowledge and hardware together to document the sizes, wattages, and impedances of all the internal (and external) Apple speakers used across the PowerPC lineup so that we can then try to findsuitable aftermarket replacements. Once we've pooled some knowledge, I'll make this a proper WikiPost with a table of speaker specs per product family, links to community-recommended replacements, and links to corresponding community replacement guides.

Here's what I've got so far:

Model	Size	Wattage	Impedance
Power Mac G3 (B&W)	70 x 40mm	2W	8 Ohms
Power Mac G4 (Digital Audio)	70 x 40mm	2W	8 Ohms
iMac G3 (Slot-loading)	28mm diameter (?)	4W (?)	4 Ohms (?)
Apple Pro Speakers	57mm diameter, 35mm depth	10W	?

I'm not 100% about the iMac G3 numbers since they're based off of various guides and posts I found online. The PowerMac G3 and G4 I verified myself. For the PowerMacs, the closest I've found to a drop-in replacement are these 70mm x 40mm speakers that are 5W, 8 Ohms. I don't know enough about speakers to know how much of a problem the Wattage mismatch is, though.

Let me know if you've got numbers to share for any other models!

If you want, I could make some measurements for the built-in speaker in the clamshell iBooks and determine whether they have a listed ohms rating.

Also, if more user-submitted data keeps coming in for different models, this would make for a great WikiPost.

 

[TheShortTimer]

Although I have two sets of pro speakers (one for an imacg4 and one for powermacg4) I don't see any specs listed on them. I do know that they are 10w output each and the

Yessir it is! Bit of a C64 love nestled inbetween my PowerPC macs and early Intel DDs.

I have a "Bread Bin" C64 with a faulty PLA chip that I really need to stop procrastinating and repair, as I've had it laying around collecting dust for ages.

Hey, I was about to ask the very same!

I had a 1701 as a kid which was matched to a C64, and later, as an adult, a friend gave me the 1701 they’d been using for years as a door weight. After a dozen or so years, I finally let that one go on CL in 2011 during my last intercity move (to lighten up my personal possessions load). It still worked as well as the original one I used to have, but aside from connecting my clamshell iBook or point-and-shoot Fujifilm camera from 2007, I didn’t have much of a use for it.

Their CRTs was excellent in their day. I have no idea which company manufactured the CRT itself.

It was JVC, as I remember reading at the time in funnily enough, an MSX magazine.

Apparently the 1701/02 are rebadged versions of the JVC TM-13U and C1455 monitors.

My latest CRT, a 1983 JVC C-1455CA. Looking it up I learned that "JVC's video monitor and ultimately the Commodore 1701 and 1702 monitors are all based off this TV.