Amplifier measurements by chasw98

[Ilkka]

As many of you have probably noticed, Chuck aka chasw98 has been performing some really interesting amplifier performance measurements over at the "science" forum. The info itself is really great but the data is scattered over that long thread so it is becoming really hard to compare the different amplifiers to each other.

Therefore I decided to compile a MS Excel workbook using all the data Chuck has provided to us. At first I thought of keeping it to myself but hey, it's more fun to share it. I did protect it though so you can't edit it.

Please let me know if there are any errors (data or grammar).

http://personal.inet.fi/private/zipm...8_11.18.07.xls (~1MB)

So Chuck, how about some CE4000 vs. XTi4000 action next?

[WillyD]

I'd take just the XTi4000 at least. We already know from the Bink test that the CE4000 is a beast. But the XTi's are unknowns w.r.t objective measurements. It would be great if anyone would send one his way.

[Exocer]

I'd like see how the Behringer amps compare to their QSC "cousins"

[WillyD]

Exocer wrote:

I'd like see how the Behringer amps compare to their QSC "cousins"

Yes. I know someone has an extra RMX2450 on hand.

[Exocer]

hmmmmm

[ISLAND1000]

[quote=-- The Bad --
1. Not all amps were tested at 96 VAC

3. Rarely if never does the end user connect a variac to their amplifier
to calibrate the AC line under certain load conditions. Even if a manufacturer
rates their power @ 120VAC, the end user has to anticipate some line loss.
If you have a data point for power @ 120VAC, power @ 96VAC, you how
have a performance range so if your line sagged to 113VAC, you can estimate
power output.[/QUOTE]

I've lived in a bunch of different apartments, condos, and houses and I can't remember ever experiencing a noticeable "line loss" causing voltage drop. Even if the voltage sags is it likely to become a permanent condition? Can't you call the power company to come and fix the problem? Or if the condition was the result of a brown out, the brown out isn't forever either.
My question is, how important is it to most DIYers, while using an amp in their homes, to know the performance under sagging voltage conditions?
I'd rather know the performance with the voltage stabilized with the variac.
I realize, thy, that you with some of your very special amps could certainly use that info simply because you have equipment that is fully capable of using up the entire supply of amps in a 15 amp circuit or even possibly a 30 amp circuit! But the rest of us have usually only one of those piddly little sub 1000 watt amps compared to your "RACK" of monster multi thousand watt amps.

[ISLAND1000]

Thy, thanks for the time you put in answering my question.
I pretty well understand the chance we have of running into a circumstance you described with one of your examples when you tested the PLX3402 in your garage with a "resistive" load. Unless we are testing under psuedo lab conditions line sag won't happen often with the "average" DIyer. As long as the guys who are using multiple drivers add up the voice coil resistances correctly and stay within the amp manufacturer's rating's 2,4,8 ohms etc. the amp loads and rated output in watts should be close to those measured using the variac at 120V.
My daily house voltage is about 112-114. There's not much I can do about that. I have the Crown XTi 4000 amp that Crown rates at 1200 watts per channel at 120 volts. The opeartors manual indicates an "operating voltage range of 100V, 120V, 220V 240V 50/60Hz. I have an older Hafler XL 280 which is rated only at 120V. My Pioneer receiver is rated only at 120V.
I have a 2500 watt rated LMS 5400 sub and have driven it toward xmax at low frequencies and although I wasn't measuring for voltage sag I haven't yet tripped the 15 amp house circuit breaker or blown the Crown amp's internal fuse if there is one or even have the amp go into protection.
The printout of Bink's amp tests show 39 amps tested and only 14 of those show a result for the
96V sag test. Out of those 14 only 4 amps hold their watt rating within a small percentage and strangely enough a couple of those amps tested at the sag voltage of 96V actually do BETTER especially at 20,000Hz!
If you can convince Chuck to perform the "sag" tests I'm good with that. With what I've got I haven't found a need for the info.
Do you know whether or not Bink included the sag tests information strictly for the pros who, while on location, often run into reduced voltage for one reason or another?

[Ricci]

Why have pro-amplifier manufacturers seemingly stepped away from using PFC for the most part? Is it hard to implement, more expensive, less reliable? There must be some explanation right?

[Ricci]

Thanks for the reply Thy. I know only some rudimentary and basic electrical theory compared to some others. Just enough to get into trouble you know? I don't know much about amp circuitry and more complicated systems, so I just pick up a little bit here and there. I appreciate the detailed explanations.

[Sonnie]

Anyone heard from chasw98 lately... I've been trying to PM him here and at AVS, but no response.

[WillyD]

Sonnie wrote:

Anyone heard from chasw98 lately... I've been trying to PM him here and at AVS, but no response.

He hasn't replied to me in a little while.

[ssabripo]

WillyD wrote:

He hasn't replied to me in a little while.

he's really busy these days....i'll send him a note and let him know about this thread