Speakers, amps, watts

Mmmm... Cocks...

Me and my roommate ordered a sweet and sassy Kraylix cabinet.
It's an arcade cabinet and it's glorious. We got all the bits taken care of except for the speakers. It takes standard 4 inch round car speakers. I just don't know a damn thing about speakers, amps, or watts.
http://www.amazon.com/LP-2020A-Lepai-Tripath-Class-T-Amplifier/dp/B0049P6OTI/ref=pd_bxgy_e_img_y
http://www.amazon.com/Mini-Digital-Audio-Power-Amplifier/dp/B007TUSXEY/ref=pd_sim_e_2
http://www.amazon.com/gp/product/B000230LBI/ref=ox_sc_act_title_2?ie=UTF8&psc=1&smid=ATVPDKIKX0DER

Does any of this look okay? I was mostly going with whatever was cheap and was available on Prime. I just plain don't understand watts though, do I need to match the speaker? And why is one amp have an output of 20 while the less expensive one goes to 100?

Dark_Side

Watts is a unit of electrical power. For speakers it's a rating for how much power a speaker can safely handle. In simple terms all you need to worry about is that your amplifier isn't putting out more wattage than your speaker is rated for.

http://hubpages.com/hub/Speaker-Watt

As to the amps, if you look close, the Mini Digital actually only puts out 4 watts a channel, I'm not sure where the 100 watt info is coming from in the specs, it may be a typo. The Tri-Path puts out 20 watts and appears to have a more advanced amplifier topology than the Mini Digital. I can't tell you which one would be better for your arcade cabinet, but at least now you'll know why the prices are different.

Mmmm... Cocks...

Ah wow, I was assuming basically the opposite haha. I was assuming I'd want an amp to drive to that max power. It's a good thing I ask questions I guess >.<
I ended up just ordering these speakers
http://www.amazon.com/gp/product/B00399HKIY/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1
They seem nicer than those cheap ones I had before and I was worried about looks (speakers are front and center). I'll use the site you linked and do me some learnin', but if anyone has any suggestions for those specific speakers I'd love to hear from you.

Donovan Puppyfucker

When checking an amplifier's power output, disregard any number that isn't accompanied by the acronym RMS.

Numbers with PMPO next to them can be completely ignored, as they're useless.

RMS stands for Root Mean Square, and is the rating of the amplifiers maximum constant power output in a realistic operating scenario.

PMPO stands for Peak Music Power Output, and is a bullshit specification that refers to the absolute maximum power an amplifier is theoretically capable out outputting for a tiny fraction of a second before it goes into meltdown.

I don't know exactly what you need your amplifier to be capable of doing, or how it's even going to be powered, but a simple 2 channel stereo amplifier should do the trick to power 2 small speakers. This seems to be a slightly upgraded version of the better of the two amps you listed, and it's a couple of dollars cheaper. It requires a 12 volt power feed. I assume you'll be powering your MAME board from a computer PSU? Because if you are, you'll be able to adapt a spare PCI-E output from that to drive the amp easily.

BlindZenDriver

chrishallett83 wrote: »

When checking an amplifier's power output, disregard any number that isn't accompanied by the acronym RMS.

Numbers with PMPO next to them can be completely ignored, as they're useless.

I second that. In fact I'll one step further and suggest staying away from anything mentioning PMPO as it is a tell tell sign of BS.

There are two things that really kills speakers. One is overheating as a result of them being being feed too much power for too long and for the purpose described in the original post that seems unlikely unless the whole system is to do double duty as a music system for parties. The other killer is signal distortion caused by an amplifier being pushed too hard and for that reason it is better to have a powerful amplifier with small speakers than the other way around.

A unit like the one chrishallett83 suggests should be perfect for the job and the speakers linked to in the OP also seems a good choice. Apart from them being the right size it is also important they are meant to cover the full frequency range - if you were to say build your own stereo system you'd typically go with a combination of speakers to cover the full frequency range so many speaker units are meant for a limited frequency range.

Donovan Puppyfucker

BlindZenDriver wrote: »

Apart from them being the right size it is also important they are meant to cover the full frequency range - if you were to say build your own stereo system you'd typically go with a combination of speakers to cover the full frequency range so many speaker units are meant for a limited frequency range.

Which is exactly why I would modify that speaker panel to fit some three way 6x9 speakers if possible.

ImaPiranha

BlindZenDriver wrote: »

for that reason it is better to have a powerful amplifier with small speakers than the other way around.

Once upon a time PA had an AV section from StormShadow - it's gone now but he said and i'm paraphrasing here, that speaker and amps are a lot like boobs and bras. If you have little boobs (amp) stuck in a big bra (speaker) they look messy and unattractive. big boobs stuck in a small bra however can look better than if they were sized exactly. You can pair, for example, a hundred watt per channel amp with 75 watt speakers and be just fine. The sound will be full and rich and so long as you don't crank it to the max for long periods you won't see any problems. I had a set of speakers taken from a 300 watt all in one home stereo that I put on an 500 watt receiver for years. Far as i know it still works 10 years later.