Mac Pro internal speaker has distorted and bassy audio

You're welcome.

Yea' the 2013 trashcan model must be dissembled to replace the funky little internal speaker.

https://www.ifixit.com/Guide/Mac+Pro+Late+2013+Speaker+Replacement/21217

So that we are on the same page, please share the exact year model.

see > Identify your Mac Pro model - Apple Support

Is the sound is OK when a set of headphones or external speaker system is connected to that Mac..?

If so, then it sounds like the internal speaker is blown, damaged or cracked from old age.

In many cases a bad internal speaker can be replaced, either by following a DIY guide or by paying an arm and leg.

Most of time, it is best to just get and use a decent wired or bluetooth external speaker system.

IF you choose to do that many-step tear-down to examine or replace the tiny speaker, be sure to do these two additional steps while you are in there:

• remove and re-seat the ribbon cables that connect the display cards, to renew their connection. These have a vague tendency to accumulate corrosion, and this will help keep the connections working longer.

• replace the non-recharging long-life Lithium coin cell PRAM backup battery as preventive maintenance. You can use the readily available CR2032 (used in car key fobs and garage door opener controls) as a pretty good replacement.

johne153 wrote:

I just got a chance today to follow that link but gosh, it looks fearsomely complicated :-(

I wonder if the spare part is even still available these days?

To make matters worse, all of the cabling and board connectors have become extremely brittle from age and heat.

One wrong move, even by an experienced computer repair technician can go down hill real fast.

There are vendors that sell used parts, but IMHO it's not worth the risk.

FWIW my microphone is working normally so might that indicate that it's the speaker, rather than the internal electronics? If anything though, I'd expect the sound to be quieter if it was a broken speaker, not louder.

Thanks for the quick reply @den.thed. It looks like the model called Mac Pro (Late 2013) - i.e. the large black tube, except that it came with Mojave, rather than Monterey.

The good news is yes, the headphone output and speaker output both work fine so I think I'll just use an external speaker.

den.thed wrote:

Yea' the 2013 trashcan model must be dissembled to replace the funky little internal speaker.

https://www.ifixit.com/Guide/Mac+Pro+Late+2013+Speaker+Replacement/21217

I just got a chance today to follow that link but gosh, it looks fearsomely complicated :-(

I wonder if the spare part is even still available these days?

<< it looks fearsomely complicated :-( >>

That procedure is complicated, but not especially difficult -- there is a difference.

Each step is straightforward, there are just a whole lot of steps.

... but as den.thed suggests,

it may not be worth the time and aggravation for that tinny little mono speaker.

den.thed wrote:

To make matters worse, all of the cabling and board connectors have become extremely brittle from age and heat.

One wrong move, even by an experienced computer repair technician can go down hill real fast.

There are vendors that sell used parts, but IMHO it's not worth the risk.

I've been there before. Can't remember what it was now but I once opened up a Mac Mini to find out if something was fixable and I stupidly broke the WIFI aerial :-(

Thanks for the great advice guys!