Measuring Amplifiers - Page 25

Where are all the fanboys that don't approve of the 'rms test method'. Come out of your closet





Spy pics of the *new* Crown XTI-6000

Wow. I seriously hope that something is wrong with that particular unit cause that is one shoddy performance. We would all be ragging on it any way if it had done 200watts per channel at 20hz into 4ohms just because it would still be so far off.

Makes the EP2500 look like a HAUS and an even better value now.

I've been checking Crown's website waiting for their response. I have an XTI2000, but if the specs are this far off I will be getting a different amplifier. If nothing is wrong with the amp then the performance is pathetic and the specs are fabrications.

I am not holding out to much hope for Crown to look at my thread (I do really hope they prove me wrong though). If there is nothing soon I may see if Chuck will mind me trying to copy over his data showing just how bad it did and than see if they respond.

Stop insulting that bird Thylantyr !

Placing Clown with big bird in the same class will result in a lawsuit from the bird !

90W into a 4 Ohm load at 20hz! WOW I am ...floored.

I sent them an email,they better respond. I hope they to not try to hide in the sand.And the failed 2 Ohm stereo tests! They have two black eyes and a broken nose now...

I am with you on that one,I have THREE Crown XTi amps(1000,2000 and the 4000) .They have some answering to do.

I would ask any Crown XTi owner to send Crown an email with the ling to this thread,like I did.


...90 F watts...!!!

* Imagine if you do a low AC line test, the scores are much less.

* Crown said it's class AB+B, [not class H].

* There was suspicion of it having a tracking power supply
due to some comments made by others but unverified
and then looking deeper into this, it didn't appear so.

* Chuck's test reveal it must be a simple class AB+B
with a simple SMPS, and the heatsink design won't support
high power if it's a straight class AB+B when doing sine
wave tests.

There were many little clues that lead me to believe something was fishy.

Another clue.
http://www.crownaudio.com/amps.htm

According to this, the XTI isn't recommended for cinema,
yet the lowby XLS's are

Lets face the facts, Crown has been going downhill after
Harmon snatched them up.




http://www.crownaudio.com/history.htm

I-Tech series is nice.

Macro-Tech I-series is a stupid marketing name for an I-Tech 'lite'.

XLS and Xs is not a Crown design.

Crown said XTI is based off the cheap CE1000/2000 design,
a known turkey in the proaudio world. [CE4000 = different animal].

Clues.. clues... clues...

I am not sure if you guys with the Crowns are registered on their forum but below is the link to my thread I started about this if you want to add anything.

http://www.crownaudio.com/forums/ind...showtopic=2438

Chuck's tests are meanginless to them because pro audio
amplifiers are usually not tested the same way.

They may laugh at you for not reading the specs.

For example, look at the XTI datasheet.
http://www.crownaudio.com/pdf/amps/139472.pdf

* The power scores don't have the word continous nor
any mention of 'RMS'.

* Specific to XTI-1000, the disclaimer that the 2 ohms/ch
or 4 ohms bridge mode is not rated for 100v versions.

* Power rating @ 1khz only [no 20hz or 20khz rating].

Well hopefully they would not laugh to much when Chucks test shows 100+ watt difference at their spec.

I joined the Crown forum. I seriously hope they answer. Right now I am fuming.

90W this is not even a cold turkey, it is a stuffed roach.

I look forward to the retest and also the bridged test. I have a feeling that the price for used QSC's are going to go through the roof.

Forget the Crown Forum..




If you want some excitement, post on the PSW forum.
http://srforums.prosoundweb.com/index.php/f/2/0/

This will rattle the cage

Maybe Chuck mistaken a Crown XTI for this ?

Canon Digital Rebel XTi

Those numbers are really strange indeed. If the amp is not defective, I have to admit that the xti series is umbelievable.

But that is not the most disturbing thing I have noticed now that this gigantic noise has risen because of this new test. What disturbs me the most is that, even people who have several different amps, good and bad, couldn't distinguish the horrible amplifiers from the good ones with their ears? Now that the amp has been tested and you have the numbers, all of the sudden everybody gets angry and starst yelling everywhere. It's like the audio hobby for some people is to watch all sorts of tests all day long and brag about ther über systems and gadgets. I tend to use my ears time to time, when comparing different systems. Not just watch some test data and numbers all year around.

90w in subwoofer application is something that everybody should have been able to hear with their ears, and not just blindly believe the high price and ultimate marketing bul****. Even I did notice the huge leap towards better sound when moving from 350w plate amp to 2kW pro amp. The difference was just something that you have to be a deaf people if not be able to tell the difference.


I do have SDX15 sonosub tuned to 15Hz.

Who are these people ?
Which amplifiers are those?

This sounds more like a hypothetical situation.

Here's my take on this. Most people in DIY home audio
have not experienced the more powerful amplifiers. Their
point of reference is low, but it works for them, until they
experience something better.

How many people meet all these requirements, raise your hand.

* You own a Crown XTI-1000
* It's driving your subwoofers @ 4 ohms/ch.
* You are playing a sine wave, not music.

Yep. I had no perspective when I began with my BKA. Then I moved up to the XS900. Now its easy to tell the difference.

The Canon XTi has more output at 20Hz into a 4 Ohm load !

exojam, remember your post....


If chuck's tests are remotely accurate I would say "Vast change" for you was simply the well know placebo effect.

I know I have placed TWO identical amps, speaker sets in front of people and then I told them set A was $2K and Set B was $500.....I think you guys know the answer to which set they like Outside of placebo drugs, audio is the only place where placebo has such a huge presence.

On deck for testing...Im sending one of my SC-1250 amps too Chuck after I use it this weekend

Cant wait to see 4 Ohms.....400 WATTS!!!!!!

This is when the suspense is deafening . . . . . . just like the power of the Crown amp was supposed to be.

The inside of my XTi 4000 has more . . . . . stuff. More capacitors and 16 transistors vs 12 for the XTi 1000. It DOES look like the same circuit board as the XTi 1000.
I also notice that on the Crown website they have added a "20 msec Burst" power rating to their wattage stats for the Itech amps. Maybe the consumer pressure to tell the approximate truth is getting to the manufacturers? Nawwwwwww.

That's a big bag of worms. I still remember the really expensive linearray Adamson cabinets being put down by users in the review section and punches literally flew. But the "officials" from Adamson did come in. If you wanna get a response, THIS IS IT!

But we'll prob get laughed at.

Why not someone try the XTi1000 or XTi2000 with a 4-ohm know sub (as close to 4ohms impedance at 20Hz), whack some 20Hz tones at 0.25m nearfield, and post the SPLs? There is indeed a noticeable difference in dB between 90W and 500W.

Thanks a lot fireanimal for sending your amp to Chuck!

Bizarre how the amp drops in output from 50Hz to 20Hz.

On an semi-related note, has anyone seen these amps?

http://www.audiolines.com/Samson-PG2...p-p-21076.html

http://www.audiolines.com/Samson-PG3...p-p-21077.html

They look like they could be good values...

Penn,

Since you quoted what I had stated, I will say it again with the same conviction. Going from the Buttkicker to the XTi was a vast improvement to me. Just because it (the XTi) seems to be weaker than advertised does not negate the difference I hear between those amps.

Also, just because of these tests does not mean I want to all of a sudden throw it away. I would just like to hear what Crown says about it if anything. I am happy with it and it will stay in my system. If you want to come on up to Boston and help me change them in and out you can tell me if you hear a difference between them in my setup.

I also notice that on the Crown website they have added a "20 sec Burst" power rating to their wattage stats for the Itech amps.

20 seconds is way too generous. It's much less than that. hehe

The scores seem to indicate some funny business, perhaps audible from
lets say 35hz on down. Lets say 35hz - 100hz the output difference is still
inaudible. You would have to do a precise test in the 20hz range to see
what happens when you play music vs. tones. Maybe the amplifier can burp
higher voltage but chokes on sustain.

Has the DSP been zeroed out for testing ?

How much below 50hz output is needed in pro-audio ( I am picturing a 4 piece band playing on a stage in some mediumsized bar)? Looks like this is a good/mediocre PA amp but a lousy LFE sub amp. Difference between this and the Dayton was the Dayton claimed to be a Sub amp and their specs reflected this. However misleading, Crown never really stated it would do anything specific output wise other that at 1 khz correct?