4 ohm watts and 8 ohm watts
 

Wally wrote:
Arny Krueger wrote:

The hidden agenda is that most PA amps have specs equal or better
than HiFi amps, if you back off their power ratings. IOW, take a
200
wpc power amp with speced 1% THD, drop the power rating back to 160
wpc, and watch the THD drop to 0.05% or better.

The wording in the spec sheet is...

20 Hz - 20 kHz @ 0.1% THD, both channels driven:

8 ohms per channel: 260 W

4 ohms per channel: 400 W

Is there any reason to think that the quoted THD is at anything
other
than the quoted output?

Sure, about 45 years of experience measuring power amps.

Good modern power amps have less distortion at lower levels than at
higher levels.

They have lower distortion when they aren't clipping then when they
are clipping.

Very few modern good power amps have as much as 0.1% THD, except when
they are clipping.

If I took the specs above literally, I'd say that they were taken with
the amp clipping a bit. OTOH, I might also strongly suspect that they
are

(1) Reasonably conservative.
(2) Designed by the Behringer marketing department, *NOT* the
engineering department.

Just guessing, but 400 watt @ 4 ohms @ 20 Hz - 20 kHz @ 0.1% THD, both
channels driven was probably the primary design spec for the amp.
Better samples of the amp probably will meet that spec at some higher
power level, maybe 410-420 watts. Better samples of the amp probably
actually do 400 wpc over 20-20KHz with 0.05% or less THD, and may have
less than 0.01% THD at 1 KHz. Back the power off to 350 watts, and
most distortion specs will drop below 0.01%.

And like I said before, pick up a good so-called PA amp - a QSC or a
Crown for example, derate it a bit, and get ready to have your socks
blown off when you take your measurements.

4 ohm watts and 8 ohm watts
 

"Wally" wrote in message
...
harrogate2 wrote:

What would be its likely stereo output into 8 ohms?

It should be 125W per chan - and 230W into 4R indicates that it
propably has a good power supply as well.

The blurb says it as a 'high current' toroidal transformer.

**A meaningless specification. What you SHOULD be told is that the
transformer IS (say) 800VA @ 5% regulation, or something similar.


--
Trevor Wilson
www.rageaudio.com.au

4 ohm watts and 8 ohm watts
 

"Arny Krueger" wrote in message
...
Stewart Pinkerton wrote:
On Sun, 10 Apr 2005 15:42:39 GMT, "Wally" wrote:

I've found a forthcoming power amplifier that I may be interested
in, but the only specs available at present are that it does 500W
into 8 ohms bridged for mono, and 230W per channel into 4 ohms.

What would be its likely stereo output into 8 ohms?

Likely to be about 130 watts/channel into 8 ohms, but that alone
doesn't make it a good amplifier...


That presumes that the power amp's power supply and other components
result in a power amp that performs like an ideal constant-voltage
source.

An amp with poorer power supply regulation will produce less than
twice as much power at 4 ohms, than 8 ohms.

For example, some of the low-cost "plate" subwoofer power amps have
the same rated power output at both 4 and 8 ohms. Their power supply
regulation, etc. is obviously a lot less than ideal.



Curiously I built a dual mono power MOSFET amp on the Hitachi design
using PCB's from Ambit (remember them?) and built and fitted separate
regulated power supplies designed by the late John Lindsey-Hood on
PCBs from Hart Electronics.

Driven into 8R and measuring the output voltage barely below clipping
(our power meter was only 50W rated) I calculated 111.5W rms. Setting
the load to 4R gave 223W rms.

I rest my case (in this instance anyway!) I will say one thing
though - it could shake windows with organ pedal notes into a pair of
Dr. Arthur Bailey Transmission Lines like nowt I've heard before or
since. Pity it developed a d.c. offset problem that I could not bottom
and thus went out of service, as did the speakers under SWMBO's
orders!


--
Woody

harrogate2 at ntlworld dot com

4 ohm watts and 8 ohm watts
 

Trevor Wilson wrote:

The blurb says it as a 'high current' toroidal transformer.

**A meaningless specification. What you SHOULD be told is that the
transformer IS (say) 800VA @ 5% regulation, or something similar.

It's not a specification, it's part of the blurb. The amp hasn't come out
yet, and the spec hasn't been published.


--
Wally
www.artbywally.com/FiatPandaRally/index.htm
www.wally.myby.co.uk

4 ohm watts and 8 ohm watts
 

"Wally" wrote in message
k...
Trevor Wilson wrote:

The blurb says it as a 'high current' toroidal transformer.

**A meaningless specification. What you SHOULD be told is that the
transformer IS (say) 800VA @ 5% regulation, or something similar.

It's not a specification, it's part of the blurb. The amp hasn't come out
yet, and the spec hasn't been published.

**Then it's not an amp at all, is it?

In computer parlance, it is vapourware.

Points:

*No one knows if the amp will exist.
*No one knows if the amp will actually meet it's claimed specifications.
*No one knows if it will demonstrate a 98% failure rate, within the first 3
months. And, before you get your knickers in a twist, I am a service agent
for several, large, multinational audio companies. One of those (highly
respected) companies, when asked by me, provided some data which showed a
67% failure rate of one of their products (within the warranty period)! That
company has a good deal more respect within the audio industry than
Behringer does, BTW.
*I am more than passingly familiar with Alesis amplifiers. I am told that
Alesis amps are identical to Behringer products. Alesis amps are cheap,
unable to meet their rated power output without external cooling and
unreliable. Be aware that I am operating under the assumption that what I
was told is correct.
*Behringer amps are not highly regarded in the professional music industry
(I know: I spoke with a few Behringer retailers yesterday, about a Behringer
crossover, I am purchasing. We also discussed mixers and amps.). Apparently,
their reliability is somewhat below average. Apparently, their mixers and
crossovers are pretty decent.
*There is no such thing as a free lunch.



--
Trevor Wilson
www.rageaudio.com.au

4 ohm watts and 8 ohm watts
 

Trevor Wilson wrote:

**Then it's not an amp at all, is it?
In computer parlance, it is vapourware.

So? I'm obviously considering it as a possible option on the assumption that
it does actually become a reality. The fact that it hasn't been released yet
doesn't devalue that consideration.


*No one knows if the amp will exist.

So?


*No one knows if the amp will actually meet it's claimed
specifications.

So?


*No one knows if it will demonstrate a 98% failure rate, within the
first 3 months.

So?


And, before you get your knickers in a twist, I am a
service agent for several, large, multinational audio companies. One
of those (highly respected) companies, when asked by me, provided
some data which showed a 67% failure rate of one of their products
(within the warranty period)!

So?


That company has a good deal more
respect within the audio industry than Behringer does, BTW.

So?


*I am more than passingly familiar with Alesis amplifiers. I am told
that Alesis amps are identical to Behringer products. Alesis amps are
cheap, unable to meet their rated power output without external
cooling and unreliable.

The other two Behringer amps have built in fans. Do the Alessis amps you
refer to have fans?


Be aware that I am operating under the
assumption that what I was told is correct.

Quite.


*Behringer amps are not highly regarded in the professional music
industry (I know: I spoke with a few Behringer retailers yesterday,
about a Behringer crossover, I am purchasing. We also discussed
mixers and amps.). Apparently, their reliability is somewhat below
average. Apparently, their mixers and crossovers are pretty decent.

Noted. Which amps?


*There is no such thing as a free lunch.

But there is such a thing as a bargain.



--
Wally
www.artbywally.com/FiatPandaRally/index.htm
www.wally.myby.co.uk

4 ohm watts and 8 ohm watts
 

"Wally" wrote in message
k...
Trevor Wilson wrote:

**Then it's not an amp at all, is it?
In computer parlance, it is vapourware.

So? I'm obviously considering it as a possible option on the assumption
that
it does actually become a reality. The fact that it hasn't been released
yet
doesn't devalue that consideration.

**Are you serious? What part of the word; "unavailable" requires
explanation?



*No one knows if the amp will exist.

So?

**Are you serious?



*No one knows if the amp will actually meet it's claimed
specifications.

So?

**Are you serious?



*No one knows if it will demonstrate a 98% failure rate, within the
first 3 months.

So?

**Are you serious?



And, before you get your knickers in a twist, I am a
service agent for several, large, multinational audio companies. One
of those (highly respected) companies, when asked by me, provided
some data which showed a 67% failure rate of one of their products
(within the warranty period)!

So?

**Are you serious?



That company has a good deal more
respect within the audio industry than Behringer does, BTW.

So?

**Are you serious?



*I am more than passingly familiar with Alesis amplifiers. I am told
that Alesis amps are identical to Behringer products. Alesis amps are
cheap, unable to meet their rated power output without external
cooling and unreliable.

The other two Behringer amps have built in fans. Do the Alessis amps you
refer to have fans?

**No.



Be aware that I am operating under the
assumption that what I was told is correct.

Quite.


*Behringer amps are not highly regarded in the professional music
industry (I know: I spoke with a few Behringer retailers yesterday,
about a Behringer crossover, I am purchasing. We also discussed
mixers and amps.). Apparently, their reliability is somewhat below
average. Apparently, their mixers and crossovers are pretty decent.

Noted. Which amps?

**Behringer amps.



*There is no such thing as a free lunch.

But there is such a thing as a bargain.

**Indeed. However, when it is 'vapourware' it is.......nothing.

AFTER the amp has hit the market and AFTER the amp has been independently
tested and AFTER the amp has been shown to be reliable, it may be worthy of
consideration. Before those facts are known, it is pointless bothering with.


--
Trevor Wilson
www.rageaudio.com.au

4 ohm watts and 8 ohm watts
 

"Wally" wrote in message
. ..
Dave Plowman (News) wrote:

It's another Behringer jobbie. Although I have little to go on, other
than other people's opinions of their kit, and my experience of the
active crossover, I'm gravitating towards the idea that their stuff
might just be rather good.

It's reasonable value for money. Let's leave it at that. ;-)

Okay, the crunch question is this: do you think the amp in question will
sound better or worse than a Cyrus 2? And why?

**No brainer. The Cyrus will sound MUCH better. The Cyrus is a real product.
The Behringer is not. It is a non-existent amplifier. It cannot amplify
anything.


--
Trevor Wilson
www.rageaudio.com.au

4 ohm watts and 8 ohm watts
 

Trevor Wilson wrote:

**No brainer. The Cyrus will sound MUCH better. The Cyrus is a real
product. The Behringer is not. It is a non-existent amplifier. It
cannot amplify anything.

No, Trevor, the Cyrus *sounds* - present tense - much better. You have no
idea what will or will not be.


--
Wally
www.artbywally.com/FiatPandaRally/index.htm
www.wally.myby.co.uk

4 ohm watts and 8 ohm watts
 

In article ,
Wally wrote:
*There is no such thing as a free lunch.

But there is such a thing as a bargain.

Yes. Behringer fall into the 'how do they do it for the money' camp. Bit
like Chinese cordless drills. But with both don't compare in performance
to the 'real' thing. Which tends to be rather a large factor in Hi-Fi.

--
*I started out with nothing, and I still have most of it.

Dave Plowman London SW
To e-mail, change noise into sound.