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post #1351 of 1783 Old 08-26-2017, 11:30 AM - Thread Starter
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ipr2-7500 idle draw 102w.

When plugged in, the amp always has blue light on (ew). When turning it on it gets brighter. Killawatt reported 0w in that state.
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post #1352 of 1783 Old 08-26-2017, 01:14 PM
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Originally Posted by notnyt View Post
IPR2-7500 2 ohm numbers.......

Thanks not. I've been waiting for these numbers.

Nice touch with the post with all of the pics as well. Thanks again for doing all of this. Great info.
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post #1353 of 1783 Old 08-26-2017, 01:16 PM
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Awesome!
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post #1354 of 1783 Old 08-26-2017, 08:24 PM - Thread Starter
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added 4 and 8 ohm numbers for the ipr2-7500, as well as noise, frequency response, and distortion
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Last edited by notnyt; 08-26-2017 at 09:18 PM.
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post #1355 of 1783 Old 08-26-2017, 11:13 PM
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I wonder what improvements if any the crest 7.5 adds. Since it's supposed to be an improved design.
I used one on my JTR os pros for a while and it was great.
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post #1356 of 1783 Old 08-26-2017, 11:40 PM - Thread Starter
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I wonder what improvements if any the crest 7.5 adds. Since it's supposed to be an improved design.
I used one on my JTR os pros for a while and it was great.
I didn't see any difference between them on the pics I saw.

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post #1357 of 1783 Old 08-27-2017, 05:57 AM
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This is all great information, thank you for taking the time to perform these tests! I noticed you said this amp is noisy as well. Is there any way you could include a fan noise level scale of 1-10 or db reading as well to include with your testing notes?
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post #1358 of 1783 Old 08-27-2017, 08:40 AM
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I didn't see any difference between them on the pics I saw.

That's pretty interesting. The crest are supposed to have a better power supply. I know Danley uses them for a bunch of different purposes (or at least used to when they came out, since they touted the crap out of them on the prosound forum)
It would be funny if they were indeed identical.
Either way, I was happy with mine when I used it. Its in a box in my garage now waiting for future use.
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post #1359 of 1783 Old 08-27-2017, 11:10 AM
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Originally Posted by N8DOGG View Post
The crest are supposed to have a better power supply.

When you say "better power supply," I assume you mean more capacitance. Yes, that has been mentioned multiple times and you can see it in the pics if you look closely. The caps in the Crest are taller.
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post #1360 of 1783 Old 08-27-2017, 11:12 AM
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Originally Posted by N8DOGG View Post
That's pretty interesting. The crest are supposed to have a better power supply. I know Danley uses them for a bunch of different purposes (or at least used to when they came out, since they touted the crap out of them on the prosound forum)
It would be funny if they were indeed identical.
Either way, I was happy with mine when I used it. Its in a box in my garage now waiting for future use.
My understanding too. It would not be cool if they were really the same due to price and the many comments stated regarding better power supply. Though at this point I don't remember where the "better power supply" came from.

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post #1361 of 1783 Old 08-27-2017, 12:26 PM - Thread Starter
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When you say "better power supply," I assume you mean more capacitance. Yes, that has been mentioned multiple times and you can see it in the pics if you look closely. The caps in the Crest are taller.
I wrote that off to perspective, but yeah, you're right. Looking closer the 4 caps in the center are taller on the crest. That's an extra 7200uF (2200 vs 4000). While not a huge difference, it will provide a little more burst capabilities.

If anyone wanted to modify the peavey for that, should be trivial, but the pricing on the pl7.5 seems to be lower than the peavey when I check B&H. Also interesting is an unused spot for a capacitor. I'd toss one in there too for another 4000uf of capacitance.

https://www.bhphotovideo.com/bnh/con...EG&sku=1071535

$1049 for the pl7.5
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post #1362 of 1783 Old 08-28-2017, 01:03 PM
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Lukeamdman did a 2 ohm test of the Crest 7.5 a couple of years back on data-bass forums and got lower ratings than your test on the Peavey. I believe it was around 1600 watts a channel, both channels driven into 2 ohms. That is a huge difference. Did he measure for a longer term or lower amount of distortion? Also would it be ok to run a couple of HT-18 v2 or UM-18's on this amplifier (one per channel). I got the Peavey from the group buy a while back but it's been sitting in my closet until my house is built.
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post #1363 of 1783 Old 08-28-2017, 01:17 PM - Thread Starter
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Lukeamdman did a 2 ohm test of the Crest 7.5 a couple of years back on data-bass forums and got lower ratings than your test on the Peavey. I believe it was around 1600 watts a channel, both channels driven into 2 ohms. That is a huge difference. Did he measure for a longer term or lower amount of distortion? Also would it be ok to run a couple of HT-18 v2 or UM-18's on this amplifier (one per channel). I got the Peavey from the group buy a while back but it's been sitting in my closet until my house is built.
Do you have a link to those test results? The prolite 7.5 should outperform this amp.
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post #1364 of 1783 Old 08-28-2017, 01:52 PM
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It was on the data-bass forum but looks like the numbers were taken down by photobucket. http://data-bass.ipbhost.com/topic/4...plifier-tests/
I believe he is on this forum also so maybe he will reply.
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post #1365 of 1783 Old 08-28-2017, 03:23 PM
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Quote:
Originally Posted by chrisfam View Post
Lukeamdman did a 2 ohm test of the Crest 7.5 a couple of years back on data-bass forums and got lower ratings than your test on the Peavey. I believe it was around 1600 watts a channel, both channels driven into 2 ohms. That is a huge difference. Did he measure for a longer term or lower amount of distortion? Also would it be ok to run a couple of HT-18 v2 or UM-18's on this amplifier (one per channel). I got the Peavey from the group buy a while back but it's been sitting in my closet until my house is built.
My guess is that the numbers are different because their test beds are different. Like a lot of tests, you can compare results done by the same person but not necessarily tests done by different people. This is one of the reasons Josh Ricci is so revered, one place where many subs are tested so you don't have to worry about inconsistent data. But you can't take a test done by Josh Ricci and compare it to one done by Audioholics although both are good testers with consistent methodologies.
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post #1366 of 1783 Old 08-28-2017, 03:55 PM
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The height of a capacitor can be misleading, but one would assume bigger is better...

Depends on the number of plates, size of the plates, plate spacing, as well as rated voltage (or at least applied-voltage).

Those internals remind me of the Crown K's, looks can be deceiving though...
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post #1367 of 1783 Old 08-28-2017, 04:11 PM - Thread Starter
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The height of a capacitor can be misleading, but one would assume bigger is better...

Depends on the number of plates, size of the plates, plate spacing, as well as rated voltage (or at least applied-voltage).

Those internals remind me of the Crown K's, looks can be deceiving though...
The ipr2 use 2200uf, the 7.5 use 4000uf.
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post #1368 of 1783 Old 08-28-2017, 04:26 PM
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The ipr2 use 2200uf, the 7.5 use 4000uf.
Examine the caps to see who the manufacturer is. Maybe a part number or series is on the sleeve. Could be that not only are they larger in value, they may have a lower ESR and higher ripple current capability.
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post #1369 of 1783 Old 08-28-2017, 06:57 PM
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Originally Posted by notnyt View Post
Do you have a link to those test results? The prolite 7.5 should outperform this amp.
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It was on the data-bass forum but looks like the numbers were taken down by photobucket. http://data-bass.ipbhost.com/topic/4...plifier-tests/
I believe he is on this forum also so maybe he will reply.
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My guess is that the numbers are different because their test beds are different. Like a lot of tests, you can compare results done by the same person but not necessarily tests done by different people. This is one of the reasons Josh Ricci is so revered, one place where many subs are tested so you don't have to worry about inconsistent data. But you can't take a test done by Josh Ricci and compare it to one done by Audioholics although both are good testers with consistent methodologies.
That early on in my testing I was using digital multi-meters to capture Vrms while driving my 21" subs as the load. Since the meters are a lot slower than scopes those numbers weren't burst/peak and more in the 1-2 second duration range.
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post #1370 of 1783 Old 08-28-2017, 09:32 PM - Thread Starter
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That early on in my testing I was using digital multi-meters to capture Vrms while driving my 21" subs as the load. Since the meters are a lot slower than scopes those numbers weren't burst/peak and more in the 1-2 second duration range.
My sine wave numbers were still a bit higher.. *shrug* I'd do a quick test of a prolite but I don't there are too many around compared to the IPR2s. I bet they can burst a good deal better. If I used these I'd even try to add another cap on the empty spot
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post #1371 of 1783 Old 12-01-2017, 12:28 PM - Thread Starter
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I have the minidsp pwr-ice250 on the bench right now, which uses the 250asx2 module.

Performance is pretty solid. With one channel running, it will output and sustain 285w into 4 ohms at 1% THD+N. 250w at <0.1%THD+N. At lower levels, THD+N drops to below 0.02%. Distortion is primarily odd order and there's a decent bump in it at higher frequencies.

Performance is significantly better into an 8 ohm load. It will output 125w into 8 ohms at <0.02% THD+N up until about 1khz, where it rises to 0.07% at 5khz. Backing off a bit, THD+N drops to below 0.02%.

There's a bit of power supply noise evident in the spectrum.























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post #1372 of 1783 Old 12-01-2017, 12:47 PM
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Is this going in a project? Been interested in this.
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post #1373 of 1783 Old 12-01-2017, 01:11 PM - Thread Starter
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Is this going in a project? Been interested in this.
2265hpl + 2453h-sl + stx825 waveguide
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post #1374 of 1783 Old 12-01-2017, 04:02 PM
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2265hpl + 2453h-sl + stx825 waveguide
Very nice. Are you retrofitting your LCR’s or a complete new build?
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post #1375 of 1783 Old 12-01-2017, 04:09 PM - Thread Starter
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Very nice. Are you retrofitting your LCR’s or a complete new build?
Not for me. It's similar to my center (linked in sig). It's a build to replace a friends front stage that's using 3677s.

My L/R are using 2452h-sl with bex4008 diaphragms on 2384 horn over 4509 lf enclosure. Using by 6x hypex nc400s amps with rme ufx+ interface hooked up to a mini pc running brutefir for processing.

These are basically gonna be like my center with the pwr-ice250 instead.
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post #1376 of 1783 Old 12-02-2017, 09:24 AM
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Id love to give you my Emotiva XPR-2 for testing but shes a tank. I've always wondered if running my Yorks off it vs a crown 1500 really makes a difference. I tried it before and couldnt tell a difference.
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post #1377 of 1783 Old 12-02-2017, 10:37 AM - Thread Starter
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Id love to give you my Emotiva XPR-2 for testing but shes a tank. I've always wondered if running my Yorks off it vs a crown 1500 really makes a difference. I tried it before and couldnt tell a difference.
If you want, will do once I get this audio analyzer situation sorted out. They just confirmed the issue I reported. Not sure how that gets missed. Once the inputs see 6v a bunch of distortion pops up. Annoying.
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post #1378 of 1783 Old 12-02-2017, 10:48 AM
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Id love to give you my Emotiva XPR-2 for testing but shes a tank. I've always wondered if running my Yorks off it vs a crown 1500 really makes a difference. I tried it before and couldnt tell a difference.
If you want, will do once I get this audio analyzer situation sorted out. They just confirmed the issue I reported. Not sure how that gets missed. Once the inputs see 6v a bunch of distortion pops up. Annoying.
I appreciate the offer but I'm not that curious to ship that monster.
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post #1379 of 1783 Old 12-04-2017, 07:09 AM
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Fp measurements up next?!
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post #1380 of 1783 Old 12-04-2017, 09:16 AM
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Fp measurements up next?!
Want to sell one of your amps?
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