Karaoke Forums

How do I match speakers to an amp

I recently purchased a VocoPro DA-3808 Karaoke mixing amp rated in their manual at 150 + 150 watt maximum power output. VocoPro tech service claims it is rated @ 100W rms/channel. Speaking of power output… How does 150w + 150w @ 8 ohms on one amp relate to 180w + 180w @ 4 ohms on another?

I want to get 2 new speakers and don’t know how to match them to the amp power-wise. I’ve been on the net looking at Peavey and Marathon and I’m seeing things like max watts, program watts, peak watts and I guess what stands for Real Mean Stuff watts. At what point is an amp too small for a speaker?

VocoPro website has this unit matched with their SV-500 (10in) speakers with a power rating of 250W max/120rms. They also have SV-600 (12in) rated @ 300 watts max

I’m looking to spend up to $325 for a pair of speakers. Any help understanding or recommending this stuff would be appreciated. At this point I realize I’ve gone about this the wrong way so please don’t beat me up too bad.

My wife and I are senior citizens and do karaoke mostly at home but on occasion we do small parties at retirement homes and catered parties for friends.

By the way… I use Winamp with an mp3+g plug-in (mp3+g v1.4) to play Karaoke from my computer. Winamp also has a plug-in (in_zip v0.6.8.5) that allows me to play mp3+g directly from a zipped file making for easier storage of my karaoke music.

Thanks in advance…. WaOvrMyHd

This gets covered a lot in this forum so if you do a search you'll find a lot of detailed information. However here's the basics. Power handling of speakers is measured typically with three different measurements. RMS, Program and Peak. Program is usually about double the RMS rating and Peak is usually around double the program rating. When attempting to match speakers and an amp, generally you want your amp to be capable of delivering 150-250% of the RMS rating of your speakers (200% is usually what most shoot for).

Now what you've noticed is that there are different power ratings for your amplifier based on the nominal impedance rating of your speakers. This is measured in ohms and for most portable PA units it will be 2, 4 or 8 ohms. So to find the right amplifier for your speakers, you need to know what their nominal impedance is and then match the specs of the amplifier to that of your speakers at that impedance. In other words, if you have a pair of speaker that can handle 200W RMS and have an impedance of 8 ohms, you'll want an amplifier capable of delivering 400-500W per channel at 8 ohms. In loose terms, impedance is akin to resistance so the higher the impedance load, generally the lower the amount of power that the amplifier can deliver.

So in your situation, if your amplifier delivers a peak of 150W per channel, you'll first need to figure out what impedance load that is measured it (probably either 4 or 8 ohms). Assuming it's 8 ohms, you'll want to find a pair of speakers with a nominal impedance of 8 ohms and power handling of 75W RMS. If that 150W/channel spec is measured at 4 ohms, you might want to see if you can find out what the spec is at 8 ohms, it's going to be somewhat difficult to find a pair of full-range speakers at that power handling level with a 4 ohm impedance (8 ohm is much more common in full-range cabinets).

Hope that gives you a start.

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DJ Tony
Let It Rip Karaoke

Thanks Letitrip... I did a search first and came up with info overload. Your explanation covering the basics was just what I needed to clarify things without confusing me. Of course it does lead to more questions but maybe now I will understand what I'm finding when I search again.

WaOvrMyHd