Gemini amps, any good?

[alexwakelin]

I've looked all over the web for any type of review on the Gemini GXA-750 with no luck. I recently built myself a subwoofer using the Infinity Kappa Perfect 12.1, many people recommend the Beheringer 1500/2500 for powering DIY subs, but those are a bit out of my price range and I can get a good price on the Gemini. The stats look good, 750 watts at 4 ohms bridged. I've posted on a couple different forums looking to get some feedback on whether or not this amp is a waste of money. It seems that no one has any experience with Gemini products.

[David Meek]

Hi Alex, welcome to The Guide. :welcome:

I'm going to move this post into our DIY forum where you'll get much more informed answers on this amp.

[Johnloudb]

Looks like www.cheapbandgear.com has some good deals on Gemini, Beringer, and Pyle amps. Sale ends today, so may too late by time you read this.
Here

[---k---]

The 750W is for bridge mono at4ohms. Where the Behringer EP1500 is rated for 1400W in bridge Mono 4ohm. So the Behringer will deliver 2x the power. I don't know how much you need.

Chas has tested the Behinger and it performed respectably. Many other amps perform less so. A Gemini hasn't been tested, but my guess is that it doesn't live up to it's specs. The Gemini is a very budget product that you'll probably just throw away when your done with it.

I'm not saying not to buy the Gemini. For a subwoofer in a home environment, it doesn't require the best amp (except for those few bassophiles). Many people were very happy with the Butt Kicker amps, and those were found to be delivering lots of distortion.

Also consider Nady amps. They can be found for very reasonable prices and are decent amps.

The Gemini has Speakon terminals, not binding posts. So make sure you buy some adapters.

[alexwakelin]

I decided to take a chance and order the gemini. I was able to get a good deal on an open box unit. The gemini is one of the few amps in my price range that is bridgable at 4 ohms, and the behringer probably puts out way more power then I will ever use. Is there a way to test what the actual output is? I don't have any fancy equipment, just a DMM.

[ThomasW]

Is there a way to test what the actual output is? I don't have any fancy equipment, just a DMM.

This is tricky to do and requires specialized equipment to do correctly.

[mjb]

You need a load (eq: a big 8 ohm resistor, rated at lots of watts) a scope, and a signal generator. Connect the sig-gen to the amps input, the load resistor and scope to the speaker output. Increase the sig-gen level until the amp's output is just seen to clip, measure the peak to peak voltage on the scope. Divide this value by 2.82 to give you the RMS voltage. Power is then this RMS voltage squared, divided by the load resistance ( 8 ). Be careful not to short anything! Always use a suitable load resistor!