hi, to put 2 speakers into jamma i can simply take the speaker + and speaker - wires and split both of them into 2 rcas, them feed the speakers with the power from jamma? Besides, how can i differ unamplified from amplified speakers?
Question is.. do all game sound amps have the same requirements? Unlikely?
The modded cabs I've seen have the jamma +/- wired to a cheap cabinet amp that can take mono input and output on 2 speakers, or have an additional stereo input too.
That way you get the best of both worlds, you can rig your CPS2 up for Q-sound or take stereo right out of your MVS etc..
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SP+ and SP- doesn't refer to the positive and negative terminals of a speaker.
On most standard Jamma games, audio is mono. You use SP+ and a common ground pin (Jamma pins 1, 2, 27, 28, A, B, e, f). So the speaker's positive terminal goes to Jamma SP+ and the speaker's negative terminal goes to any of the aforementioned Jamma ground pins.
Some MVS boards output stereo sound from the Jamma edge. In these cases this is where SP- is used. So SP+ (right speaker positive terminal) and a Jamma ground pin (right speaker negative terminal) is the right speaker output and SP- (left speaker positive terminal) and a Jamma ground pin (left speaker negative terminal) is the left speaker output.
I think that's wrong. The aforementioned MVS boards aren't jamma, so they don't adhere to jamma spec.
I always wire my speakers to SP+ and SP-. If the negative terminal is meant to be grounded then SP- and GND will show continuity. However, it's also possible both SP+ and SP- are floating (SP- goes below ground), which means if you wire the speakers to SP+ and GND, you will possibly blow the amp.
hm, now i`m confused...
what caps should i use?
so in jamma boards i dont need an amplifier or a high-low converter with unamplified speakers, but i see u have divergence in wiring them. another question: if the board outputs just mono, there`s no difference wiring the speaker - into a second speaker? And the boards that output stereo, like cps2, i can wire into the rcas, but i can use too the speaker - to output stereo?It will simplify trading the speakers to diferrent boards...