I was just about to pull the trigger on a 950/7100 combo, when something pulled me up short. The specs on the 7100 state 7 x 100 wpc all channels driven at 8 ohms. Fine, no worries there. THIS spec is what stopped me:
7 x 165 wpc all channels driven at 4 ohms. Pardon me? 7 x 165 = 1155 watts total. Considering the amp pulls 1200 watts at maximum , how the can it deliver 1155 watts ouput?

I am well aware that the condition for 5 channels needing 165 watts apiece at the same instance is VERY low in probability, not to mention 7 channels needing it. What bugs me is that the specifications SAY it can do that. So what, am I missing here?

I really want an outlaw combo, but when the numbers don't add up, I become very cautious.


Thanks in advance to all.

You should read your original post and help answer what your real question is? The AC rated power usage is 1200Watts and your comparing a DC rated output of 1155Watts, they are not the same.

Ideally, if the amp were 100% efficient and not current limited, you would get 200W/channel out of 7 channels into 4 ohms. This is not the case since the Amp is likely heat or current limited for the 4 ohm load.

And, when I tested concert musical loading on power usage, the duty cycle of the music we were testing, including pink and white noise, never went above 50%. Meaning, if we expected 200W and set up our power sourcing for such, the reality was we only needed 100W. This was just a simple test and not conclusive of all setups.

Thanks for the information, perhaps I don't have the needed background to pose the question in a more intelligent fashion.

Agreed, that the DC wattage is not the same as AC wattage.

The generalized idea that I followed is that channels (C) x rated power (RP) should be around 80% ( or more if the amp has a higher efficiency (E) ) of 1200 watts. ( C*RP<= 1200* E ) ( 7 * 165 <= .8*1200 )

Apparently I am off base here as that idea has at least one hole in it. Time to do some research on my end.

Thanks for the pointer.

Bob045

lucky for us that the ac is not directly output as power, we would never have anything with a lot of power.

i dont think you know how an amp works.

for the most obvious explanation, capacitors are employed to store "power" for the instant that the amp requires more than can be directly produced from the ac input(s). the larger capacitance, the greater the ability to output high power instantaneously.

theres much more than that, but that should give you a glimpse as to why what you were asking is possible.

keep in mind that PEAK is different than RMS.

------------------
This post has been brought to you by curegeorg, thanks for reading.

Hi curegeorg,

*lol* I always thought I knew how an amp works.

I also know the diff between peak and RMS. Peak is self-explanatory, RMS ( Root Mean Square ) I always thought of as continous max power.


However, it is obvious that the theory (hypothesis ? ) I was following is incorrect.

Regarding the spec for the 7100 at 4 ohms, is it for peak or RMS?

I think the best folks to comment on this issue are the Outlaws. Have you tried an email to them?

im sure it is RMS.

------------------
This post has been brought to you by curegeorg, thanks for reading.

Yes I have emailed them as they are the definitive source. What they say goes!

Sorry, I forgot to wrap this up. Steve who responded to my question was very informative and answered my questions in this post to my complete satisfaction.

Thanks Steve.

Bob045