Amps n' Cabs n' Watts n' Stuff

[fuzzybassist]

So the amp/head for my p.a. system is a 60 watt head, and although this is pretty low, I would love to move onto bigger and better speakers. I know about clipping and blowing tweeters and what not, but if my head is able to make the speakers produce sound,is it safe, no matter how underpowered it is? Or is it not even realistic for a 60 watt head to make sound come out of speakers rated at like 300 or so :P Any information regarding the subject would be appreciated, but I mostly would like to know about underpowering speakers, especially minimum wattage needed to push speakers rated at certain watts. Thanks for any help you can provide

[GardenoftheDead]

The wattage of a speaker cab is a maximum, not a minimum.

[transients]

if you're running a 60 watt head through 300 watt speakers, you'll be fine. the speakers will stay pretty clean, maybe even sound a little flat and not too dynamic, and the amp will break up long before the speakers ever do. speaker wattage is basically, as gardeenofthedead said, a maximum. if your speakers are 50W, when your amp goes over 50 watts, the voice coil melts and the speaker blows. on the other hypothetical hand, if you're using a 15 watt amp on 1000 watt speakers, it will sound pretty unresponsive and boring. of course, all of this varies greatly with different amps, different types of speakers, etc.

i'm no amp expert, but the rule-of-thumb is to get speakers with a wattage double the watts of your amp. for example: 50 watt amp, 100 watt speaker.

i use 50 watt amps with 50 watt speakers though, and haven't had a meltdown yet... but if i get any spikes in power (AKA... transients ) where my amp goes over 50watts, i'd be screwed.

[fuzzybassist]

You guys are always so helpful

[The4455]

If you wanted to upgrade your P.A. it would be better to go with powered speakers and a small mixer. And in some cases you wouldn't even need a mixer!

[D.o.S.]

Underpowering speakers is a myth.

[fuzzybassist]

I would but it seems like powered speakers and a mixer is just crazy expensive. My current set up consists of a head that puts out 60 watts at 8ohms and the two speakers meant two be ran with it (12inch woofer, and horn each) , plus three 12-15 inch homemade cabs (from broken guitar amps and one from goodwill) all linked together. I heard something about if i link them together like I do I'll be able to use a more powerful amp/head to push the speakers to their full potentials. The reason I'm having these issues is that the PA isn't being heard over the two guitar and drums my band uses, and I feel like it should because all its competing against is a Peavey tnt (one 15inch speaker) and a crate amp (two 12inch speakers). Neither are turned up more than half way (generally at about 4). I'm just not sure where the problem is. The PA has like double the speakers, but I can barely hear it. Any suggestions?

[The4455]

Putting the speakers up higher would help, also using a higher gain microphone or simply turning the gain on the microphone's channel up more.

[new05002]

theres a bunch of different speaker ratings, peak, RMS, program. make sure u know which 1 ur talking about

[McSpunckle]

Speaker power ratings are actually pretty complicated. The general rule with musicians seems to be to match the RMS rating of the speaker with the output of your amp, but for most music, that's actually really overkill, since music from a 100 watt amp will generally be putting out an average of 10 watts for cleaner music, and more for something noisier and/or more compressed.

However, an amp rated at 100 watts, if it's really heavily clipping, can put out twice that in average power sometimes. Amps are generally rated with a clean sine wave, and clipping will square off the sine wave, keeping it up at a higher level longer. Thus, more average power (RMS). Guitar amps are pretty much designed to clip, so the speakers have to be much closer to the power rating of the amp, or even higher.

Underpowering woofers with higher RMS ratings isn't really a huge issue, since you'd likely burn up the amp first, but tweeters are designed with the power they'd likely get in mind, not what they'd get from a massively clipped amp. Even a pretty under-powered amp can burn up a tweeter if it's clipping hard. So, basically, even with under-powered amps, you want to be careful about clipping; and, if you're amp isn't very powerful, you're much more likely to clip.

As far as actually using 300 watt speakers for a 60 watt amp-- a lot of times speakers that handle more power aren't as sensitive. Sensitivity is really the rating you're looking for when you want your speakers to be loud. Get the most sensitive speakers you can that have enough power for your amp. Though, unfortunately, speakers that are more sensitive tend to have less bass response (hence why bass amps are so much more powerful than guitar amps), so you need to look at frequency response and such too. Older speakers tended to be more sensitive because there weren't such powerful amps available.

You said you were linking the cabs together-- are you sure the amp is still seeing 8 ohms?

[fuzzybassist]

I doubt that is is still seeing 8 ohms:P but I'm not sure what to do about that.