No sound from Jamma Speakers?

[lettuce]

Have just fired up my Jamma Cabinet for the first, after fitting a PC with J-PAC etc, everything worked ok, the monitor was my main worry but that was great, but i didnt get any sound from the fitted cab speakers! Theres 3 in total, one left, right, and a centre one thats placed in a box, i guess it acts as a sub, should i be getting sound from these speakers by just connecting the jamma connection to the J-PAC, or do i need to do some re-wiring?

[AlanS17]

The speakers are expecting an amplified audio signal. They might be receiving it, but it'll be so low it's not moving the cone. You'll need an audio amp of some sort if you plan on using the cab's original speakers.

[lettuce]

So whats the easiest ways to get sound, just plug speakers in the PC sound card and use them?. Why do some people insist on using the Cabinet speakers with an amp, why not just use the PCs Sound card with PC speakers, surley that would be the easiest route to take?

[Havok]

So whats the easiest ways to get sound, just plug speakers in the PC sound card and use them?. Why do some people insist on using the Cabinet speakers with an amp, why not just use the PCs Sound card with PC speakers, surley that would be the easiest route to take?

PC speakers are easier, since they are internally amplified - they usually have to plug in to power as well as the pc. Usually, you can get better sound from the cab speakers with a good car amp - but that is more of a pain. If you get a good set of pc speakers with a sub, you can most likely get better sound than what you'd get from the built in ones, especially since they are probably getting on in years, and are most likely cracked and not performing up to new specs...

[RayB]

So whats the easiest ways to get sound, just plug speakers in the PC sound card and use them?. Why do some people insist on using the Cabinet speakers with an amp, why not just use the PCs Sound card with PC speakers, surley that would be the easiest route to take?

What you just said doesn't make sense. In either situation your sound would have to come from a PC sound card. The difference is between amplified and non-amplified speakers. It's not that illogical really, if you consider that even stereo systems use unamplified speakers .

The problem here stems from the fact that over the years, sound-card manufacturers stopped making cards with built-in amps, because you get much better sound, and a whole lot less interference if you use proper external amplification.

So, "why do some people insist on using the Cabinet speakers with an amp?" -- For authenticity and so that their JAMMA cabs remain JAMMA cabs? I don't know... In the end it's your choice. Plenty of people have just used PC speakers.

[CheffoJeffo]

Have just fired up my Jamma Cabinet for the first, after fitting a PC with J-PAC etc, everything worked ok, the monitor was my main worry but that was great, but i didnt get any sound from the fitted cab speakers! Theres 3 in total, one left, right, and a centre one thats placed in a box, i guess it acts as a sub, should i be getting sound from these speakers by just connecting the jamma connection to the J-PAC, or do i need to do some re-wiring?

From the JPac FAQ ...

What about sound?

The JAMMA standard is for only one speaker, mono sound. This is one of the reasons the J-PAC does not contain a sound amp. Other reasons are:
There is no readily available 12V supply. Using the available 5V supply would not enough power.
Using a separate mains adaptor would create issues with local line cord types.

How do I wire for sound?

There are several easy ways to do this:
Use a sound card with an on-board amp. Either wire this to the speaker connectors on the J-PAC to use the cabinet speaker via the JAMMA connector or by-pass the J-PAC and wire directly to one or two speakers in the cabinet.
OR: Use a set of mains powered PC speakers. Either remove the speakers from their cases and mount in the cabinet or simply place inside the cabinet. This will give the advantage of power stereo sound.

As others have pointed out, JAMMA standard is for amplified sound. It is certainly easy enough to bypass the JPac and use amplified PC speakers, but do yourself a favour and don't hack up the existing sound system too much (in case you want to restore).

Cheers.