What does a 17WRMS internal amp in a deck put out with the volume cranked, and gains all the way up? If I am off base on this, then please explain it to me, just all my reading, and experience has brought me to the conclusion I have stated

Mark

 

I haven't seen too many speakers blown off deck power...... and when I have it was the tweeters, not the woofer.....

 

YES -- it is possible and common for people to blow a speaker on deck power, especially if they crank bass to +11 (pun intended) and turn loudness on.

If you can hear distortion, then the amp IS clipping and this MAY damage your speakers.

Having "too much" power allows you to keep the gains low and run your amp at lower levels. Many class A/B amplifiers are biased towards class "A" in the initial stages of output.

If an amp is rated for 25 watts RMS, the distortion this number comes at is not necessarily the optimal circumstance for your speakers.

Think of it this way, many engines have a red line of 6000 rpm or higher -- would you drive your car 200km at 6,000rpm?

 

Maybe you should read what's said in that little link you posted there bud.
Mainly the part right at the start that says "Abuse and the defective 'wing nut' (an idiot) connected to the volume control blow speakers with low powered amplifiers."

 

^ the argument is no wing nut can maintain themselves any better with more power over less power...... infact, being a 'wing nut' myself.... I can tell you from personal experience.......

 

dongchen_han - good work, you answered the question.

The point is people can, and certainly do, damage speakers with far less power than the speakers are rated for.

I'm not sure how many blown speakers you run into Haunz, but being in retail electronics for some time I, and Mike who has more time in than me, have seen a tonne. Oddly the customer "never even turns it up. ever."

Never underestimate the power of a moron.

 

I run into alot blown speakers meself.... everything car audio I get my hands on gets reconed by ME..... IMO (and with possible exception to tweeters)... if the mild increase you will gain in output with a clipped signal is enough to burn out your speaker, chances are you would still be in trouble the day you listen to them for a little longer or the next time an ultra low note comes along.......

you can really see alot from a simple THD versus power output graph........ at nominal load most amps just don't have the extra juice.......

do you really see that many speakers blown with deck power ? I mean I've beat the out of alot of speakers in my day and the best answer I have is the speaker's must be seriously overrated..... (which many probably are... it seems 20w nomial can turn into 60 or 80 'peak' pretty quickly with some companies)

 

I can honestly say I see 2-4 clients a week with "blown" speakers. My favorite aspect of this is the dumbfounded look they all seem to share when you explain that they overdrove the speakers. "But I hardly turn them up..." then you go to the car and you have them play it "the way they normally listen" to their stereo.

Nine times out of ten is sounds like Bill Frissell gone made (ie free jazz "feedback" experiment or in other words at least 7% Distortion [pun intended]). In addition loudness is on, "bass" is as high as possible AND (usually if they think they are into "sound quality") "treble" is ONLY plus "3".

Yes, grasshopper, clipping and the THD it brings is a bad thing for your speakers.

 

I had that genius in my store today as well Mike, he made good time getting from there to here.

 

Here are a couple typical output vs THD graphs for HU's... kenwood, Alpine, and RF.....


The kenwood boosts output from 15w clean to 25w @ 20% THD.... to 30w... with ONLY 40% distortion!!! (that is no where near listenable, IMO..... )


This Alpine does 27W @ 1% THD and 32W @ around 7%... thats probably barable for your average 'wing nut'.... not bad...


This RF dosen't look so good... only 12w before THD starts to clime, and at 18w we are up around 15% THD..


its clear all have a limit on max output... thats why output and THD roll off the way they do.... its also clear that after a certain point THD skyrockets, often with little gain in actual output.....

Still with '60 watt' pioneer,kenwood,sony, ect ect ect speakers that are really only ment for 15watts RMS its pretty clear you will be in trouble with that alpine HU... however even with unclipped output, you would still be in trouble !!!!!

On the otherhand the RF probably wouldn't be able to damage much of anything, clipped or not...