I was just wondering about my Memphis amps (Olde School)
10-26-2008, 09:02 AM
#1
50 Watt CAFz'r
Thread Starter
Join Date: Sep 2008
Posts: 229
I was just wondering about my Memphis amps (Olde School)
My Memphis 1500D runs at:
1 x 750W @ 4 ohms (0.75% THD)
1 x 1500W @ 2 ohms (1% THD)
@ 12v
and my Memphis 3004 runs at:
4 x 75W @ 4 ohms
4 x 115W @ 2 ohms
@ 12v
I believe all the speakers are wired for 2 ohms and I know my subs will be. Now my system runs at 14.6v when my car is running according to my cap.
So does that mean that my amps are putting out more power then those specs? I know that those amps are under rated and are already more powerful then those specs @ 12v.
1 x 750W @ 4 ohms (0.75% THD)
1 x 1500W @ 2 ohms (1% THD)
@ 12v
and my Memphis 3004 runs at:
4 x 75W @ 4 ohms
4 x 115W @ 2 ohms
@ 12v
I believe all the speakers are wired for 2 ohms and I know my subs will be. Now my system runs at 14.6v when my car is running according to my cap.
So does that mean that my amps are putting out more power then those specs? I know that those amps are under rated and are already more powerful then those specs @ 12v.
10-26-2008, 03:52 PM
#3
From what I have learned over the last few months, yes they will be putting out more power with a higher input. More in=more out usually.
Take Elemental Designs for example, they rate at 12.5v iirc (say 65wrms ch), but real world at 14.4 they go into the 90 wrms range.
Look at these high end SPL guys on the board. They run 16v and get something like 7k from a 5k rated amp I think.
Lots of people on here can explain it better than I, but to me, the answer is yes.
MTX is also famous for just plain underating the amp. I have a TC4004 which is supposed to be 400wrms all in, but certificate states 519wrms.
50 a channel at 4ohm, and certificate says 72, but that IS rated at 14.4. If it were 72 at 12.5, then maybe 90+ at 14.4.
Someone better at math than me can probably post up a formula.
John
Take Elemental Designs for example, they rate at 12.5v iirc (say 65wrms ch), but real world at 14.4 they go into the 90 wrms range.
Look at these high end SPL guys on the board. They run 16v and get something like 7k from a 5k rated amp I think.
Lots of people on here can explain it better than I, but to me, the answer is yes.
MTX is also famous for just plain underating the amp. I have a TC4004 which is supposed to be 400wrms all in, but certificate states 519wrms.
50 a channel at 4ohm, and certificate says 72, but that IS rated at 14.4. If it were 72 at 12.5, then maybe 90+ at 14.4.
Someone better at math than me can probably post up a formula.
John
10-26-2008, 08:56 PM
#7
50 Watt CAFz'r
Thread Starter
Join Date: Sep 2008
Posts: 229
not from what I have been told, atleast with all the original Memphis amps they are under-rated. A Memphis tech said that the ST-1500D actually pushes close 1800rms at 12v.
if I had a meter I would test it myself...
if I had a meter I would test it myself...
10-29-2008, 11:34 AM
#9
50 Watt CAFz'r
Join Date: Feb 2008
Posts: 163
The real answer is yes and no. As soon as a large output amp starts making some real power, the voltage in your charging system will decrase in voltage from the draw form the amp.
You are going to have to do some serious alternator upgrades to feed that amplifier 150-200 amps and keep the voltage up to 14.4
(Notice the twin 200 amp alts in the picture of my engine in my avatar.)
You are going to have to do some serious alternator upgrades to feed that amplifier 150-200 amps and keep the voltage up to 14.4
(Notice the twin 200 amp alts in the picture of my engine in my avatar.)
10-29-2008, 11:57 AM
#10
Well, if you want to be real about it. The amp will probably never put out half of that rated power due to multiple barriers like efficiency, impedance rise, added resistance and wear/tear in "olde school" worn out internals, blah, blah, blah.
