New CEA Ratings or magical amps?

Ryan from Ohio · Post by **Ryan from Ohio** » Sat Sep 09, 2006 4:51 pm

Ok,

Since Ive been looking into an amp for my car Ive been noticing a LOT of funky business. Truth be told I havent been really looking at amp specs in about 8-10 months really.

Im seeing stuff like this:

RMS Power Output:
* 450 watts, Punch Series 4-Channel Amplifier
* 4 Ohms: 60 watts RMS x 4 chan.
* 2 Ohms: 110 watts RMS x 4 chan.
* 4 Ohms Bridged: 225 watts RMS x 2 chan.

Now back in "the day" when you had 60 WRMS x 4 channels @ 4 Ohm, when you bridge them channels it would then be 120 WRMS x 2 channel @ 4 Ohms.

So it leads me to wonder if these new ratings are making things even more deceptive than before, or is there some new mircale amp topology I never noticed?

I guess they really mean the 225 WRMS x 2 @ 4 Ohms as its rated @ 450 WRMS total...

Either that or Im just so F'ing tired I cant think str8...

two4fifteen · Post by **two4fifteen** » Sat Sep 09, 2006 4:58 pm

an exert from our ampilifier faq

"If we had our perfect amplifier, upon bridging it we would have a single channel amplifier with exactly four times as much power as any one channel of the amplifier in "normal" stereo mode, assuming a 4 ohm speaker load. "

take smoker's elevation amp he's selling for example.... 125 x 4 @ 4 ohm. 500 x 2 @ 4 ohm

Ryan from Ohio · Post by **Ryan from Ohio** » Sat Sep 09, 2006 7:00 pm

Hehe,

I was just watching a Movie and was thinking about this thread. I realized what I was failing to think of earlier

Now that its time to go to bed, well I think Im finally waking up!

Not the new CEA rating or new amp topology, just tiredness clouding the mind :happy055:

Not to self, get at least 5 hours of sleep before speaking publicly again

two4fifteen · Post by **two4fifteen** » Sat Sep 09, 2006 7:09 pm

lol it happens...

cargodz · Post by **cargodz** » Sat Sep 09, 2006 11:46 pm

two4fifteen wrote:lol it happens...

Yeah, just look at my post from a couple days ago... I was saying amp instead of alt

Ryan from Ohio · Post by **Ryan from Ohio** » Sun Sep 10, 2006 6:31 am

Ya it just bugged me.

Yesterday was just a very dopey day for me, lol and rightfuly so.

I feel kind of embarassed about that post but am going to leave it as a reminder to all, even us mods have bad/stupid days.

Its a good thing I didnt buy an amp yesterday like I about did. WOuld of made som BAD choices...

Post by **GlassWolf** » Sun Sep 10, 2006 6:19 pm

RF is correct. This is the way it's always been.
60x4@4ohms =
120x4@2ohms=
240x2@4ohms bridged

bridging the channels gives the same combined power at 4 ohms as you have in stereo at two ohms, where in this case stereo is all 4 channels.

Ryan from Ohio · Post by **Ryan from Ohio** » Sun Sep 10, 2006 6:49 pm

Lol,

ya yesterday it took me a few hours to remember that.

Bad day, you come back lata you hear?

two4fifteen · Post by **two4fifteen** » Sun Sep 10, 2006 6:54 pm

did anyone else notice glass's little error whilst "straightening out" ryan...

geolemon · Post by **geolemon** » Sun Sep 10, 2006 7:19 pm

It mainly depends on how regulated the power supply is.
Or, could be the result of stressing the power supply enough to sag.

A completely unregulated power supply would result in a true 120x2 at 2 ohms, from an amp that was 60x2 at 4 ohms.

A very tightly regulated power supply could result in an amp that wasn't much higher than 60x2 even at 2 ohms.

With a power difference like this though, I don't suspect a regulated power supply, I suspect a saturated (read: stressed) power supply.

I thought you were going to complain about RF's habit of publishing certain "rated" specs for their amps, then including birthsheets that admittedly don't conform to rated numbers (ie distortion spec ">" is circled

) with wild, way-up-there power numbers to make people feel like they got "a more powerful amp" than rated.