Audio amp power spec: Stereo vs. "bridged"?

[DaveC]

Into 8 ohms, per the manual:
180 W/channel, stereo
560 W, mono mode (bridged)

Regardless the inflated numbers that all manufacturers publish, why would the
number for the mono mode be so much higher than the stereo spec? Shouldn't it
be double the rating for stereo?

Thanks,
--
DaveC
me@privacy.net
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[John Popelish]

DaveC wrote:

Into 8 ohms, per the manual:
180 W/channel, stereo
560 W, mono mode (bridged)

Regardless the inflated numbers that all manufacturers publish, why would the
number for the mono mode be so much higher than the stereo spec? Shouldn't it
be double the rating for stereo?

If the limit is imposed by the supply voltage, not the current
capability, then bridging the two amplifiers doubles the possible
output voltage, which multiplies the peak power by 4. Evidently the
current limit occurs before this full multiple is produced, when
bridged.


--
John Popelish

 

[John Fields]

On Sat, 20 Dec 2003 10:49:56 -0800, DaveC <me@privacy.net> wrote:

Into 8 ohms, per the manual:
180 W/channel, stereo
560 W, mono mode (bridged)

Regardless the inflated numbers that all manufacturers publish, why would the
number for the mono mode be so much higher than the stereo spec? Shouldn't it
be double the rating for stereo?

---
Stereo:



+38V--->\ <--- -38v
\
O
|
[8R]
|
0V

P = E˛/R = 38V˛/8R = 180.5W



Bridged:


+38V--->\ <--- -38v
\
O
|
[8R]
|
O
\
+38V---> \<--- -38v


P = E˛/R = 76V˛/8R = 722W


--
John Fields

 

[DaveC]

Thanks.
--
DaveC
me@privacy.net
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[Myron Samila]

What kind of amp?

Specifications are derived by many different ways in order to market the amp.

If car audio, hehe, its all marketing.

Typically, if a professional power amp can go down to 2 ohms/ch min and has a max output
of 1000W/ch, then it can bridge to 4 ohms min and will see somewhere in around 2000W
bridged.

Manufacturers do the following to get their "specs".

1 khz input signal
QSC Audio specs their amps using 20hz-20khz both channels driven at 120VAC.

Typically, if your amp has a minimum impedance handling of 2 ohms, you can only bridge to
4. You're putting both channels into series with one another.

I've been in the professional audio field for 10 years, and I love it

--
single channel driven
higher voltage on the primaries (check what voltage they test it at).

Myron Samila
Toronto, ON Canada
Samila Racing
http://204.101.251.229/myronx19


"John Fields" <jfields@austininstruments.com> wrote in message
news:k699uvk6orviogfamknefagrlda982ebh3@4ax.com...

On Sat, 20 Dec 2003 10:49:56 -0800, DaveC <me@privacy.net> wrote:

Into 8 ohms, per the manual:
180 W/channel, stereo
560 W, mono mode (bridged)

Regardless the inflated numbers that all manufacturers publish, why would the
number for the mono mode be so much higher than the stereo spec? Shouldn't it
be double the rating for stereo?

---
Stereo:



+38V--->\ <--- -38v
\
O
|
[8R]
|
0V

P = E˛/R = 38V˛/8R = 180.5W



Bridged:


+38V--->\ <--- -38v
\
O
|
[8R]
|
O
\
+38V---> \<--- -38v


P = E˛/R = 76V˛/8R = 722W


--
John Fields