How do you know its meant for a piezo transducer?
The standard PC speaker header is also 4 pin (with the center 2 pins not connected).

The manual indicates that the 4-pin speaker header is indeed just that, a standard 4-pin header.
An 8 ohm 0.25W speaker will be fine.

My Packard Bell also has the Piezo speaker and DOS games don't sound very well either, but, since there's a header for the PC speaker, my plan is to connect a 4-pin cable between the motherboard and the Tandy 3-voice Compatible Sound Card (already made the cable with a resistor and capacitor) and see how that works out.

bjwil1991 wrote:

My Packard Bell also has the Piezo speaker and DOS games don't sound very well either, but, since there's a header for the PC speaker, my plan is to connect a 4-pin cable between the motherboard and the Tandy 3-voice Compatible Sound Card (already made the cable with a resistor and capacitor) and see how that works out.

The thing is, his motherboard doesn't have a piezo speaker on-board (at least not according to the manual). Most likely it was used in the case instead of the standard speaker setup.

Ah. I have a couple of cases from the early 2000's that use the piezo speaker, and only 1 of my retro PCs had the speaker mounted in front of the case from the early 1990's.

Just plug in the better speaker into the motherboard and it will work fine.

The motherboard isn't driving enough current through the speaker to be a problem. Motherboards would also be designed to handle the small 8 ohm speakers in the first case.

Nnever heard of a situation where changing the PC speaker damaged a motherboard.

Yeah it works well, i also use a 8 Ohm Speaker, it sounds much better then a piezo.
Now i can run Pinball Dreams and it sounds ok 😁

Don't you have a soundcard in that machine? Many of them have connectors to connect your motherboard speaker output. This way you can direct your MB speaker output to your normal speakers (it probably will require a 4 pin to 2 pin dupont cable by the way).