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Measuring Amplifiers - Page 7

post #181 of 1917
Wow, I thought they would have published the max wattage at 1% THD or whatever the standard is. Anybody who has a BK amp powering a sub better look into buying the buttkicker transducer and put the amp to do the work it was meant to do!
post #182 of 1917
Quote:
Originally Posted by crackyflipside View Post

Wow, I thought they would have published the max wattage at 1% THD or whatever the standard is. Anybody who has a BK amp powering a sub better look into buying the buttkicker transducer and put the amp to do the work it was meant to do!

I think most of us are just gonna sell the BKA and get a much, much better amp.
post #183 of 1917
Gonna be a lot of BKA's on ebay real soon...
post #184 of 1917
Quote:
Originally Posted by deneb View Post

Gonna be a lot of BKA's on ebay real soon...

post #185 of 1917
Thread Starter 
Quote:
Originally Posted by deneb View Post

Gonna be a lot of BKA's on ebay real soon...

I just saw one on Cult this morning!
post #186 of 1917
Quote:
Originally Posted by chasw98 View Post

I just saw one on Cult this morning!


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.. lol ...

post #187 of 1917
Thread Starter 
Quote:
Originally Posted by thylantyr View Post

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.. lol ...


FS: Buttkicker BKA 1000-4A Amp
« Thread Started on Yesterday at 7:51pm »

--------------------------------------------------------------------------------
I'm selling my 1 month old BKA. Can't use it for my sub (only used it for 1 hour anyway). Asking $200 + shipping. Pay via M.O. or PayPal (add 3% for PayPal fee).
post #188 of 1917
On other note, I think you should do all tests at 1% THD, to match Binks test
and it's a nice number that is considered 'inaudible' and you can get the highest
power from the amp at this 'clean' level. Testing the amp at different distortion levels skews the comparison
data from amp to amp. If all amps are done at 1%, 20hz, 1khz, 20khz, it's all apples to apples. Worse
case, ditch the 1khz and 20khz because most people need the high power for subs
anyways. lol

Don't forget the 96VAC tests
post #189 of 1917
Thread Starter 
Quote:
Originally Posted by thylantyr View Post

On other note, I think you should do all tests at 1% THD, to match Binks test
Don't forget the 96VAC tests

If you look at post 152, I did do a 1% THD test and that was at nominal line voltage (no variac). This amp has very poor FR so it is not really worth it to do it at any other frequency and 100 Hz was somewhat of a stretch for it. I believe it put out 'most' power between 30 & 40 Hz.
post #190 of 1917
The generic class D design usually is rated up to 200hz, so poor FR is exepected
from these generic designs {think car audio class D too}. The really special designs
we see from the big pro sound companies try to get their 'switching amps' to do
full range, nice. But the poor FR amps are usually just marketed to drive subs so
there is no mystery.
post #191 of 1917
chasw98, I was considering sending an Adcom GFA-585 for you to test. I would like to know your thoughts on the power and sound quality versus the pro amps. Would you be open for testing?

Thanks
post #192 of 1917
Thread Starter 
[quote=staffcurtis]chasw98, I was considering sending an Adcom GFA-585 for you to test. I would like to know your thoughts on the powe
Quote:
Originally Posted by staffcurtis View Post

chasw98, I was considering sending an Adcom r and sound quality versus the pro amps. Would you be open for testing?

Thanks

I have tested 2 Adcom amps that Yuriv brought over one afternoon a while back. They were classic old school class AB amplifiers that have very low distortion and their rated wattage is usually exceeded by 20% or more in bench testing. They are exellent amplifiers but they are looked upon as 'under powered' in todays world.
The GFA 585 is seen as one of the best ever built by Adcom and still holds its vaue very well. Just look here .

If you would like for me to test it, I would absolutely do it for you. PM me for details.

Chuck
post #193 of 1917
I have an Adcom 555 MKII I snagged a long time ago as my test bench amp.

I like it bridged mono mode, 600W @ 8 ohms. It's a nice amp, the heatsinking is weak
if you operate the amp at lower impedance.

A couple of years ago when I built the budget line array, I ran the 555 at 0.8 ohms/ch
for the tweeter array, QSC RMX2450 at 2 ohms/ch.

Eventually [10 minutes] the Adcom goes into thermal protect because it's fanless.
The QSC doing the same job will run all day.

I wouldn't hesitate and trade my 555 for RMX. lol
post #194 of 1917
Hey Chuck, I have a weird idea.

What if the Buttkicker test was in error, now everyone is dumping their amp
at firesale prices... Hypothetical, people selling them for $150.... Next thing
you know, Chuck is buying all these amps and later reposting the test...

Sorry guys, my bad, the BKA does alot better... Now chuck can sell his $150 BKA
for $200 and make $50 profit on each amp.

// scare tactics//

// joke //
post #195 of 1917
Quote:
Originally Posted by thylantyr View Post

Hey Chuck, I have a weird idea.

What if the Buttkicker test was in error, now everyone is dumping their amp
at firesale prices... Hypothetical, people selling them for $150.... Next thing
you know, Chuck is buying all these amps and later reposting the test...

Sorry guys, my bad, the BKA does alot better... Now chuck can sell his $150 BKA
for $200 and make $50 profit on each amp.

// scare tactics//

// joke //

Now that would be funny! I believe Chucks testing is pretty accurate when it comes to the buttkicker. I knew they were pretty much hype, so I waited for his response to confirm this, or that maybe I was crazy. I'm even selling the BKA I have now, and buying an EP2500 for that purpose! I would recommend that others use the behringer for shakers instead now as well (from Chucks testing results).
post #196 of 1917
Quote:
Originally Posted by chasw98 View Post

... I have tested 2 Adcom amps that Yuriv brought over one afternoon a while back. They were classic old school class AB amplifiers that have very low distortion and their rated wattage is usually exceeded by 20% or more in bench testing. They are exellent amplifiers but they are looked upon as 'under powered' in todays world...

I'm lucky that I don't need that much power. The only time I've seen the clip indicators light up was when I brought them over for testing. That afternoon, I disconnected a Hafler 9505 from my main speakers and replaced it with that low-powered Adcom. I haven't removed it yet because it also sounds good. Plus it runs cooler; it really does a fine job. Even with the worst-case scenario in my setup, the continuous (and instantaneous) power output doesn't come close to the amplifier's limit.

BTW, when we tested my Alesis amp, you commented that it had the best measurements of the bunch. Before that, I had been planning to get rid of it. When I do my own testing but this time at 1 W and 100 mW, which is where my amplifiers spend a lot more of their time, I found that the Alesis amp has far worse numbers than the others.
post #197 of 1917
Quote:
Originally Posted by yuriv View Post

I’m lucky that I don’t need that much power. The only time I’ve seen the clip indicators light up was when I brought them over for testing. That afternoon, I disconnected a Hafler 9505 from my main speakers and replaced it with that “low-powered” Adcom. I haven’t removed it yet because it also sounds good. Plus it runs cooler; it really does a fine job. Even with the worst-case scenario in my setup, the continuous (and instantaneous) power output doesn’t come close to the amplifier’s limit.

I had four adcom 5500's hooked up at one time, and I was able to get them to clip. Now the sound was very loud too, but I just want even more.
post #198 of 1917
Hey chasw98 what about trying to contact this dude thread here http://www.avsforum.com/avs-vb/showthread.php?t=855865 and test his PA1.3 he is talking about :-) never know he might be serious cheap price with a lot of power or snake oil :-)


Quote
PA Amplifiers.. Who's interested?
http://www.sharebigfile.com/file/19...atalog-xls.html
There's an excel document of all the Amplifiers I will have. If you're interested in any one of them let me know, pm me, and I'll get you the cheapest price possible. These are built to order and are custom designed, you won't find these in stores. I'm only posting it here because I think more DIY guys who would be interested would look here. They will be made to 120v Spec. I know the DIY crowd might like some of these Amps, especially the GDA series for speakers.

I know it seems like advertising, but I'm really just trying to hook you guys up. I can get more power to you guys cheaper than anyone else. Just take a look at internal pics, EP2500s on steroids for a little bit more. The more I order the cheaper I can get them to you, I have to have these shipped in 60ft containers.. it's not cheap.


If a mod thinks this should be in the FS section, let me know.
post #199 of 1917
O.K., Once I show my wife the pic of the smoking buttkicker, it will wind up on the street. (She asked me how I could sell it to someone else - with perhaps a serious flaw) I do not agree that maybe a one or two instances should ground the entire fleet. But, like I said, it is dead amp walking.
So, what will have at least the same output (advertised or actual), small as possible, and similar bang for the buck? No fans would be nice also.

How do you all feel about this one?
http://www.partsexpress.com/pe/showd...number=300-810
post #200 of 1917
Sorry to go off the course of this thread but ...

Chas,
Since the Ep1500 did so poorly in the higher frequencies, would this place it in a class below integrated receiver amplification in the higher frequencies? (as far as linearity goes) Or...as i would hope, is it still significantly more powerful in the higher frequencies than integrated amps?(HK 235 to be more specific)

I'm not so sure that you have objective data on receiver amp sections yet, but I wonder if you could make an educated guess as to the answer of my question?


Thanks again for running these tests. you're the man
post #201 of 1917
Thread Starter 
Quote:
Originally Posted by Exocer View Post

Sorry to go off the course of this thread but ...

Chas,
Since the Ep1500 did so poorly in the higher frequencies, would this place it in a class below integrated receiver amplification in the higher frequencies? (as far as linearity goes) Or...as i would hope, is it still significantly more powerful in the higher frequencies than integrated amps?(HK 235 to be more specific)

I'm not so sure that you have objective data on receiver amp sections yet, but I wonder if you could make an educated guess as to the answer of my question?


Thanks again for running these tests. you're the man

I am not sure I would place it below integrated receivers. The EP1500 is a dedicated power amp and produces 'mo better' power than an integrated receiver can because of a dedicated power supply, usually only producing 2 channels instead of 5 or 7, and no possible interference from other sections of the unit. To compare the power amp sections of an EP1500 to an HK235 is not really fair to either of them. But if you were to compare the L/R channels of an EP1500 to the L/R channels of an HK 235, I think you would find that the EP would sound better mostly because of increased headroom. You kind of have to get back to common sense and take the measured numbers as only one piece of the puzzle. The EP1500 measures 1%+ THD at 20 Khz at full power. The THD number quickly drops to inaudible (and unmeasurable) levels at normal usage. If, for instance, you are cruising along using 25 watts (a lot!) of amp power from both the HK or the EP and a 6 db transient comes in the music, which amp has the headroom to reproduce it? Not the HK according to numbers. That 6 db transient has just called for 100 watts from the amplifier for a time duration of as long as the transient lasts (could be short or long). If you were to measure the EP1500 and the HK 235 at 100 watts per channel (only 2 channels each) distortion and noise in the HK would be much worse than the EP. I would have to say that the EP1500 would run circles around almost any 100 watt/channel multichannel receiver out there. But then you would need 3 or 4 EP1500's to be equivalent and the space to put them in. Which means a multichannel receiver can sometimes be the easiest most convenient unit for a particular user and some will want a rack of dedicated power amps.

Oh and I have run tests on many receivers over the years (not too many lately), and I would have to say that every power amplifier, even the worst ones, are usually better than a receiver. Not always, but usually!

Chuck
post #202 of 1917
Thanks a lot for the explanation Chuck!

Seeing that the Ep1500 had done so bad in the higher frequencies was relatively scary to hear considering I used it with the Natalie P's and It did sound WAY better than the HK.

For some weird reason I thought it was possible for this dedicated amp to perform worse in the higher frequencies than an integrated amp....had me a little scared but thats for the clarification. much appreciated.
post #203 of 1917
Chuck, what do you think of multiple amps, like 4 EP2500's, compared to a cinenova or any other super multichannel amps out there? Is the full-range quality missing with the Behringers?





(I'm secretly trying to get you to test the Cinenova amp )
post #204 of 1917
Quote:
Originally Posted by crackyflipside View Post

Chuck, what do you think of multiple amps, like 4 EP2500's, compared to a cinenova or any other super multichannel amps out there? Is the full-range quality missing with the Behringers?





(I'm secretly trying to get you to test the Cinenova amp )

You're good at keeping secrets (because everyone knows secrets are kept in parentheses)
post #205 of 1917
Does anyone here have experience with the QSC PLX3602 amps? I can either get two of these (rated at 3600w each), or EIGHT behringer ep2500's for the same money. The QSC is a better amp, but going against EIGHT behringers could prove tough.
post #206 of 1917
Thread Starter 
Quote:
Originally Posted by staffcurtis View Post

Does anyone here have experience with the QSC PLX3602 amps? I can either get two of these (rated at 3600w each), or EIGHT behringer ep2500's for the same money. The QSC is a better amp, but going against EIGHT behringers could prove tough.

The QSC amps are very good. But you will have better redundancy with 8 amps versus 2 amps. You would probably also tend to run 8 amps at less gain than 2 amps with more gain. That would depend on the use and the load you are going to drive. For instance if you had 8 drivers that would be driven by 8 mono bridge mode EP2500's, then you are looking at a nominal 4 ohm load per amplifier (2 ohm load per amplifier channel). If each amp had the gain set to the 50% mark, then you would relatively be working the amp very easy. With only 2 QSC amps, you would have 4 channels of amplification and therefore you would be running 2 drivers per channel. Each amp channel would see 2 ohms just like the EP2500's but you would only have 2 power supplies to feed those 4 channels of amp instead of 8 power supplies. I also would think that you would be running the QSC's at a higher gain level even though they produce more power. Don't forget your electric bill. The 8 EP2500's will draw some power, probably more than 2 QSC's that are more efficient.

This assumes 4 ohm drivers to be used in a subwoofer. Since you didn't tell every little nuance about the situation, I can only make broad conclusions. This is a Thylantr disclaimer lol
post #207 of 1917
I have four subs that have dual 4 ohm coils. Each Behringer would be bridged to a 4 ohm load. Each sub would only need 1000 watts RMS per amp, and each sub would have two amps. The Behringer's would be running at half duty, so they would not be pushed to their limits. I would also have it setup where only one amp would be running normally, but when I had a movie on that required more bass, I could turn the rest on (sorta like class H technology on the physical level ). This would save my electric bill from all those amps just idling.

Let me know
post #208 of 1917
8 amps, 4 subs! No way . . . . keep it simple. I vote two amps, less wiring less parts to go wrong.
post #209 of 1917
Chuck, thanks for all of your work on this.
post #210 of 1917
Thread Starter 
Quote:
Originally Posted by staffcurtis View Post

I have four subs that have dual 4 ohm coils. Each Behringer would be bridged to a 4 ohm load. Each sub would only need 1000 watts RMS per amp, and each sub would have two amps. The Behringer's would be running at half duty, so they would not be pushed to their limits. I would also have it setup where only one amp would be running normally, but when I had a movie on that required more bass, I could turn the rest on (sorta like class H technology on the physical level ). This would save my electric bill from all those amps just idling.

Let me know

4 subs = 4 physical cabinets
A) dual 4 ohm coils = 1 driver with a dual 4 ohm voice coil per cabinet?
or B) 2 drivers with dual 4 ohm voice coils per cabinet equaling 4 total voice coils between 2 drivers.
or C) 4 subs having 2 each 4 ohm coils so that would mean 2 amps per sub.

With 4 subs and 2 EP2500's per sub running in bridged mono mode, you will get 4800 watts per cabinet "according to specs".
With 4 subs and 2 QSC PLX 3602 amps, you will get 1 channel per cabinet for a total of 1800 watts per cabinet "according to specs".

Even with the EP2500 not able to produce 2400 watts at steady sine wave, it will still put out as much as a single channel of the QSC. You will get tremendous headroon using 8 amps and 4 subs with 2 4 ohm drivers per sub.

Using the QSC, you will not get as much headroom and you will not get the flexibility to turn off some cabinets when you are watching I Love Lucy reruns.

Redundancy and headroom with EP2500 PLUS
8 amps wiring complexity and electricity used MINUS

Efficiency and simplicity with 2 QSC PLUS
Lack of headroom, redundancy, and flexibility MINUS

That is how I see it. If you were going to choose between 4 EP2500's and 2 QSC's, I would 100% say get the QSC's, but 8 EP2500's affords so much headroom that the amp will be running well below its limits and ratings. The wiring complexity will only occur when you set it up and should not plague you forever so that is a "one time" minus. Using a lot of electrcity is an "all the time" minus unless you only turn them on when needed. If you burn up or damage an amp, you are only out 1/8 th of your system with the EP's, whereas you are out 1/2 of your system with the QSC's.

What do you think?
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