Hey,
I have Boston Acoustics Rally components which their website vaguely describes as being able to handle anywhere between 20-250W (RMS or not I dont know) Anyway Suppose a set of components can handle up to 100W RMS, is it better to give them more power (like use an amp that can provide 150RMS) and lower gain for more control or will this put too much stress on the speakers, especially given that I sometimes listen to music with lots of distortion... Is there a general rule for how much power you want to give a speaker to have good SQ?

I generally start to back off once I have 2-3x the power the speaker is rated for.

Basically - it is hard to have TOO much power :D

right now i have 100*2 for my midbass, but a few days a go i tried to put 550*2, and the result WOW!!!!

SO I should get a 300W by channel amp and set gain to about a third so that I dont burn the speaker and amp does not distort? Isnt that dangerous however for speakers?

As with any speaker I want enough power to drive the speaker to the point where it was designed and have an amlifier and electrical system big enough that I can drive the speaker under any condition without worrying that the amp will start clipping.

when is an amp clipping?

An amplifier clips when it reaches the maximum output voltage it is designed for, or more accuratetly, tries to exceed that voltage.

I forget the math right now, but I heard that it requires some astornomical amount of power to accurately recreate the dynamic range of a real orchestra. Supposedly the peak SPL was very high..

OK, a little research... During the average performance, a Double-Bass can produce 134+dB and an Oboe can do 135.4dB.

So, OK, I'll do the math.. Assume the average good quality component set produces about 85dB of output when driven with 1 Watt of power. I'll give the whole thing a boost and say that we have two channels, so the efficiency is up to 88dB at 1 Watt.

If we negate the effects of power compression, thermal limits and coen excursion, and assume a real increase of 3dB in output for every doubling of amplifier power, it would take roughtly 50,000W to produce 135dB.

Yes, we get some help from the car with the transfer function and what-not, but this is the necessary power for an anechoic, realistic performance.

You can never have too much power.

X2

So the whole idea behind lots of power, or getting more than the speaker is rated for is for dynamic crescedos in the music, and to give the amp enough "dynamic headroom" to recreate the signal without clipping.
Kinda like a 4 Cyl, and a V-8 trying to pass a semi on the highway, up a steep hill, carrying a trailer, and passing really quick from same speed as semi.

Get me a V-12 Merlin!!

Nice one Dave.

I'd just like to add that 16 bit CDs don't have the dynamic range to cover 135db. Most classical cds are recorded with a large amount of low level information removed, or artificially increased in level, to compress the everything onto a normal 16 bit CD. The human ear doesn't resolve details below 50db very well though, so it's not as noticable as it may seem.

PLOW, welcome to my world! [img]smile.gif[/img] I love power.

the bret, I'd like to warn you that while you may be able to afford some monster amps, the power system to support them can be just as expensive. 125 to 150 watts works well for mids and tweeters.

Adam

^^^^ What he said.


Too often I see people running (so they think) BIG power. Well, amplifier power isn't something magically that happens from thin air. You need an electrical system beefy enough to support those power requirements. So if you think big power amps cost money, don't forget that beefing up your power system also costs money....... some times a lot of money. If you don't have it, then that big ole amplifier you have may not be making anywhere near it's rated power.

I think that giving a drivber what it optimally needs is a financial smart way to go. But I also like MO POWER. The more the better. :D

^ But Tom.......just get a cap :D

^^^^^^^Ahahaha [img]graemlins/thumb.gif[/img]

That 135dB Dave is talking about is a bit different from what you're talking about - it's the peak SPL. You're talking about dynamic range. The effective dynamic range would be cut down to about 95dB because the noise floor even in a good hall is about gets down to about 40dB, occupied with people.

That's also assuming the recording equipment introduces a noise floor lower than that.

It's no wonder that a lot of people who perform in orchestras often become hard-of-hearing when they get older... Then again, a DoubleBass at 135dB won't harm you as much as the Oboe at 135dB.

of course, that 135 dB is measured where??? at the bell of the oboe? in the seats? honestly, having been to many orchestra performances, 135 dB isn't achieved at any position where the audience is listening to the orchestra.

You guys are cool..

I don't know where the 135dB was measured, just some numbers I yanked off a hearing loss comparison I found on the net, but it mirrored the numbers I saw in another story in a home audio mag a few years back.

Call it 3 or 6 dB less, you still need 10,000-15,000 watts..

It's all irrelevant because I have two caps, so I am fine!

Anyone familiar with Cinepro home amps [img]smile.gif[/img]

MAN, Dave has two caps
[img]graemlins/jawdrop.gif[/img]
That's insane!

I know, but I try and do everything 'over the top'..

I am thinking of taking the battery out of the car and running a total of FOUR caps instead. Caps weigh so much less..

I am going to do it as soon as my billet titanium hood prop rod arrives...

Hey man look in to those BATCAPS...I hear they're awesome, 'cause my friends buddy who like has this totally pimped out Prelude and a stereo that hits 170 db easy, said so!!

Man, if I ran two of those... I could hit 340dB!!!

yeah man, but if you ran JL W7s, with JL amps, since they're the best, and 2 batcaps, WITH 4 1 farad caps... you're talking like 800 dB man... easy. 'specially if you used the JL High Output box, cuz U know that JL is the shizzle...

Well that covered about 80% of car audio conversations in North America... thank you for leaving out the Yoyoyo and the daaaaaaaammmnnn and the always popular shiznit... dog

That be the bomb yo.

[img]graemlins/thumb.gif[/img]

I'm going to print this out and post it over my desk!

You have all restored my faith in human nature!

Efficency helps too. [img]smile.gif[/img]