2 Channel Amplifier Help

[[ASLYVY]]

hey guys,
just deciding what amplifier to run to 2 6x9's in the parcel tray for the time being

they are 1000w max pair...so 500W peak but dont know what RMS that would make them?..maybe 100?..anyway just need some help on the power rating of the amp i should use..and how to install it as i want to try a DIY instead of paying big $$$$ for autobarn to do it as they have fitted my speakers and headunit


thanksss!

[VrWagz1]

500w/2 X .7= RMS roughly. Off the top of my head that comes to about 180watts

[[ASLYVY]]

thanks for that!
so this means ill need around a 500w-1000w 2 channel amplifier so it dont stress too much powering them?...

[commsirac]

hey guys,
just deciding what amplifier to run to 2 6x9's in the parcel tray for the time being

they are 1000w max pair...so 500W peak but dont know what RMS that would make them?..maybe 100?..anyway just need some help on the power rating of the amp i should use..and how to install it as i want to try a DIY instead of paying big $$$$ for autobarn to do it as they have fitted my speakers and headunit


thanksss!

One can only make some guesses about the numbers you have supplied.
A max rating and peak rating need some qualification.
1000W max and 500W peak is written on the box?
There are no standards for either.
1000W peak, or sometimes abbreviated to PMP0(peak music power) says the speakers can survive a power burst of that much for a given time(but the time is never specified.....and that is really the only thing that matters....typically they may be claiming a millisecond or two........its is a completely useless rating.......well it puts big numbers on the box anyway)

The 1000W peak can be converted to a RMS peak value by mulitplying by 0.7, but again the figure is meaningless.

What you are interested in is the RMS continuous figure, which will be much lower, there is no way of calculating this from the peak values.
However, the figure of 180W RMS quoted earlier might be in the ball park.

The question you need answering....can only be answered if you know the efficiency of the speakers, rarely ever quoted because the numbers dont impress the average car stereo buyer.

Unless the speakers are hopelessly inefficient, 100W continuous RMS /channel is all you would ever need to power 6 x 9 to uncomfortable levels in a car.

You dont need to buy an amp with the same power ratings as the speakers, you can buy one with much higher or lower ratings(despite some nonsense written by so called audiogurus), you can damage the speakers with either with incorrect operation. Just make sure you buy an amp that is going to get the speakers as loud as you need them without distortion.

Its also worth remembering to buy an amp using the same logic. Look at the continuous rating for 0.1% distortion........silly numbers can be arrived at for PMPO etc.

[VrWagz1]

pmpo= peak max power output, and applies to anything, not just audio related.
If you look on a graph of a single ac cycle(ie 1 hz), pmpo is the peak to peak reading.
RMS= is .7 of the +peak half cylce (ie, dc or constant equivilant)
This is why pmpo figures need to be /2 before multiplying by .7
Still like you said, the figures quoted by some manufacturers are way optomistic and are not woth the paper they are written on.

[[ASLYVY]]

ah ok thanks for all the info guys....just to clear things up they are soundstorm 6 x 9's..and quote on the back of each speaker that the rating is 500W Max...i am looking at a 4 channel amp atm with a max rating of 600W (Sony)...and 60W RMS per channel (1.0% THD) and 130W per channel at (0.1% THD) THD means distortion right? dont really know what the THD %'s mean but yeh...this would be sufficient to power them up without damage??
thanks

[commsirac]

pmpo= peak max power output, and applies to anything, not just audio related.
If you look on a graph of a single ac cycle(ie 1 hz), pmpo is the peak to peak reading.
RMS= is .7 of the +peak half cylce (ie, dc or constant equivilant)
This is why pmpo figures need to be /2 before multiplying by .7
.

While there is no standard on pmpo, it does not/should not stand for peak to peak power(that would just be an absurd claim as it in no way as the power versus time graph is a "rectified graph"), it is meant to represent peak music power.....which is calculated by multiplying the max value(amplitude) of the voltage and current which occur at the same time in the cycle. There will be no -ve peaks of power, as the product of -ve voltage and -ve current is still +ve.

[commsirac]

ah ok thanks for all the info guys....just to clear things up they are soundstorm 6 x 9's..and quote on the back of each speaker that the rating is 500W Max...i am looking at a 4 channel amp atm with a max rating of 600W (Sony)...and 60W RMS per channel (1.0% THD) and 130W per channel at (0.1% THD) THD means distortion right? dont really know what the THD %'s mean but yeh...this would be sufficient to power them up without damage??
thanks

Are you looking at 2 different amps?
generally the THD is lower at lower power values on any given amp.
You do need to keep distortion figures in perspective. The very best audiophile speakers would struggle to do less than 1-2% distortion, car speakers 5-10% so whether the amp introduces 1% is neither here nor there.
The %THD is not a measure of how much damage they will do, but basically the 1% figures is the highest one you should take any notice of. They use to quote car amps at 10% thd, only marginally away from clipping.....that's where speaker damage can occur when the waveform clips creating serious levels of high frequency rubbish that will overdrive your tweeters first and other parts of the speaker later.
THD: total harmonic distortion.
It is tested by playing a tone into the speaker and using a spectrum analyser to test for harmonics of that tone in the output. Harmonics being integer multiples of the test tone.
Typically the test involves feeding single tones into the speaker: if 1000Hz was fed into the speaker, they are looking for the extra harmonic frequencies generated by the speaker....2000Hz, 3000Hz, 4000Hz etc. But the effect would be checked with lower frequencies as well. You probably wont find any claims for these by the manufacturers

Typically these dont make the music sound bad(like clipping distortion), they can actually make the music sound fuller, but still not a good thing for those that like accurate reproduction.
For amplifiers the thd is quoted when a 1000Hz tone is used.

As b4 100W/channel is plenty....60W/ch should be good too.

[VrWagz1]

While there is no standard on pmpo, it does not/should not stand for peak to peak power(that would just be an absurd claim as it in no way as the power versus time graph is a "rectified graph"), it is meant to represent peak music power.....which is calculated by multiplying the max value(amplitude) of the voltage and current which occur at the same time in the cycle. There will be no -ve peaks of power, as the product of -ve voltage and -ve current is still +ve.

Of course peak2peak is an absurd claim, its like telling everyone your power points are 600v, your not lying its true but its not rms. But in general thats the way a marketing department of a compnay will come up with the figures plus add in whatever they think, as the big numbers look inpressive. You've spent too much time being a google engineer. With audio it may not be 100% accurate to use the peak to rms equasion because of this, but it is the best calculated guess you will get to compare to a genuine rms claim of a reputable manufacturer.

[commsirac]

You've spent too much time being a google engineer.

if I dont know about a topic......I dont post.....or provide direct links to articles that may be of help to the thread.

[VrWagz1]

if I dont know about a topic......I dont post.....or provide direct links to articles that may be of help to the thread.

Aplogoies, that was a bit rough of me

[Tasmaniak]

2x100 will drive them perfectly man....trust me on that one.