You could have played your guitar through your hifi if you wanted. ;) The impedence wouldn't likely have matched and it may have sounded like crap (depending on the hifi of course! Some of them apparently sounded nifty though I never tried) but you could have done it. The volume knob saves your speakers from damage. ;)

The only thing that damages a speaker is getting an incorrect voltage sent through it or having TOO MUCH signal pumped through it so that you rip the speaker cones. You can rip your speaker just as easily playing an album too loudly, though.

So to answer your question: you're fine. Just make sure you don't crank the volume too much, period. Doesn't matter if it's a guitar or any other source.

Greg

thanks for the info; my understanding was that it was the frequencies and possibility of feedback that could damage the speakers rather than the voltage difference. (for the record, of course i tried it anyway, using my tape deck and recording level knob to amplify to an acceptable level!)

There was a time when guitars, and especially bass guitar, could not be reliably pumped through the typical home stereo speaker at ANY volume because of the dynamic range. A vynl LP had very limited dynamic range (what, 60-70 dB?) and an electric guitar's plucked string would tear the poor loudspeaker right off the spider assembly. But with "modern" CDs, speakers have to reproduce more like 90 dB dynamic range, so the electric guitar is not such a terror to them. You've still got to be careful, though.A carefully set compressor/limiter can help in the recording process and help prevent speaker damage at the same time....

moonbaby.... you're wrong

actually the dynamics of MANY lp's are greater than 90% of cd's today...

the marketing stunt that told you anything should be "cd ready" is utter BS...

and the speakers in a typical guitar amp is of far poorer quality than most hifi speakers...

the only problem i can see is if you have to much energy below 100Hz as i could easily drive the amp into clipping... a thing you should not try on a typical stereo...

so using common sense it should not be a problem....

I've been there and killed stereo speakers with my guitar - it was fun(back when I was younger, stupider, and it was prob way too loud)

the big thing to keep in mind is that although a CD is capable of a dynamic range of 90 odd dB, the actual dynamic range of most CD's is a lot less.Most mixed & mastered CD's these days tend to be compressed etc pretty heavily. (I won't say whether that is good or bad, there is 1000 other forums covering that touchy topic. for the nature of this, I am just stating fact.) so the actual peak (the loudest fleeting bits of sound) to RMS (how loud it appears to be) ratio is a fair bit smaller than that of a Guitar.
On top of that, as iznogood touched on, is that CD's usually have all the subsonics etc dealt with, so not a lot of dangerous (20-40 Hz or so) sound is coming off the CD.

Basically that means that the better the power handling of the speaker, the safer your guitar through it is.

A few years back, there was a noticeable gap between "stereo" and "Studio" speakers, the stereo ones being not all that good at handling rouge sounds, and Studio monitors were made to handle the crap thrown at them, while still being accurate.
It's not so much the case today, Sound on sound did a comparison between a few stereo and studio speakers that proved a few interesting things:

http://www.soundonsound.com/sos/Jun02/articles/monitors.asp

I'm more inclined to judge the speaker on how it feels (a big magnet, large voicecoil, heavy cone will handle more) rather than what it claims to be.

There is a huge amount more that goes into making onespeaker more appropriate than another, but that's the general basics of it that should save some expensive mistakes....

All that aside, I personally can't stand the sound my guitar through something with tweeters in it. Give me an aincent old flabby Celestion G12 with a response of 300 to 3k any day.

Have Fun All
8-) Al

I stand by my statements. First off, the "average" vinyl record album in the 60's and 70's did NOT have the dynamic range of a modern CD( or a modern LP), nor did it have the frequency range. In addition, the low end program material had to be very carefully limited due to the inability of both cutting heads and phono cartridges to track it properly. Anyway, electric guitars regularly DID tear up the typical (and even "high end") stereo speakers due to the instruments' wider dynamic range than the speakers were designed to handle. I know what I'm talking about..I have a 50/50 partnership in a live sound company here and my partner runs a loudspeaker re-coning business. You should see what people can do to a "stereo"speaker. Seeing what some of the manufacturers put in their boxes is enough to keep me from ever buying, say, a Genelec.The fact that a loudspeaker has a limited bandwidth of, say, 100-5KHz. for electric guitar reproduction does not make it "inferior" to a 40-20KHz. studio monitor. The design of ANY musical instrument loudspeaker IS for it to handle the dynamic transients of a live musical instrument and to "sculpt" that speakers response to the intended use. NOBODY wants to hear a Strat cranked through a Marshall head run into a "hi-fi" box with a 20KHz bandwidth! PEACE...

with you on all you just said moonbaby 8-)

Keep it up, Al

To add to what the others have mentioned, having worked for Celestion in my mispent youth. One of the biggest problems with hifi speakers is that the tweeters are not designed to take any significant power. Any clipping becomes extra work for the tweeter to do. Since guitar distortion is essentially clipping that's been filtered by the amp speaker, anything over 3K is gone. But in a hifi any clipping (of any frequency) goes straight to the tweeter and it doesn't take much to blow them. It's always a fun trying to explain to a customer that they blew their tweeter.

I don't think anyone would say that you can't damage your speakers by turning up too loud. I think the point was simply that plugging in won't inherently damage your speakers as an action in and of itself. Turning up too loud once you're plugged in may very well do so, though. ;)

You can tear your speakers by turning up your hifi too loudly, period.

Greg