Build Your Own Arcade Controls Forum

Main => Main Forum => Topic started by: pharoah007 on September 07, 2009, 09:52:55 pm

Title: Are arcade speakers 4 ohm or 8 ohm?
Post by: pharoah007 on September 07, 2009, 09:52:55 pm

I have a set of old car speakers that are still good, was wondering if I could swap them for the ones in my arcade machine (old and blown) 

The car speakers are 4 ohm.

My cab is a Dedicated MK2 from Midway, stock speakers and wiring or said speakers.

If the Arcade speakers ARE IN FACT 4 ohm...then are the car speakers I have a straight swap?


thanks in advance all.

Title: Re: Are arcade speakers 4 ohm or 8 ohm?
Post by: drventure on September 07, 2009, 10:06:13 pm

I wondered the same thing recently. I found this on a website

"If you just want to find out the nominal impedence of the speaker e.g. ist it 4, 8 or 15 ohms then there is a rough & ready way. Just use your multimeter to measure the DC resistance of the voice coil i.e. across the speaker terminals (with nothing else connected) and multiply the answer by 1.3. So if the DC resistance is say 6 ohms then the speaker is nominally 8 ohm impedance. "

http://www.epanorama.net/documents/audio/speaker_impedance.html (http://www.epanorama.net/documents/audio/speaker_impedance.html)

Haven't tried it yet, but it seems reasonable.

Title: Re: Are arcade speakers 4 ohm or 8 ohm?
Post by: severdhed on September 07, 2009, 10:56:59 pm

the speaker that was in my Donkey Kong cabinet was 4ohm, but that doesnt mean that all of them are.

Title: Re: Are arcade speakers 4 ohm or 8 ohm?
Post by: MaximRecoil on September 08, 2009, 02:04:35 am

Most of them are 4 ohm; in fact, 4 ohm speakers are pretty standard in DC-powered sound systems. The reason for this is because DC systems are usually being fed a low voltage, in the neighborhood of 12 volts, and you need bigger/bulkier amplifiers, and bigger currents (amperes), which need bigger power and ground wires for a given level of amplification than you do for a home system running on 120 volts. That's why a 1000 watt home amplifier can have a typical 16 or 18 AWG power cord while a 1000 watt car amplifier would have at least 4 AWG power and ground wires.

In any event, using 4 ohm speakers rather than the traditional 8 ohm speakers that are usually used in home audio, helps to offset this, because they will pull twice the power from a given amplifier design and given input voltage than 8 ohm speakers will (assuming a typical amplifier design).

In any event, it is perfectly okay to use 8 ohm speakers in a system designed with 4 ohm speakers in mind, but you'll only get half the power from your amp. It is not recommended to use e.g., 2 ohm speakers in a system designed for 4 ohm speakers, because you are pulling twice the power through it compared to 4 ohm speakers (again, assuming a typical amplifer design).

So going with the higher impedance speakers gives your amplifier an easier life, at the expense of power delivered to your speakers. Going with lower impedance speakers gives your amplifier a harder life with the benefit of more power delivered to your speakers.

Title: Re: Are arcade speakers 4 ohm or 8 ohm?
Post by: Finchbyrd on September 08, 2009, 02:43:39 am

I had 2 4" 8 ohm speakers in my Marvel Superheroes cab.

Title: Re: Are arcade speakers 4 ohm or 8 ohm?
Post by: pharoah007 on September 11, 2009, 11:32:56 pm

Right on, thanks all.

Anything else I should know about the swap?

Anything particular I should look for (common issues with speakers)

Thanks again

Title: Re: Are arcade speakers 4 ohm or 8 ohm?
Post by: Finchbyrd on September 12, 2009, 10:48:59 pm

Yeah, discoloration on your monitor due to lack of shielding on the speakers.