Crown XLS2502 Stereo Amplifier Review

[AudioLover73]

In his test, he said warning lights came on. He didn't say it shut off right? Unless it shuts off, I'm not going to worry too much about warning lights.

...I think we have a different understanding of what pro audio is. If the budget gear works for you that's fine. Like I said, we also used it for low budget jobs that weren't to demanding.

 

[Geert]

In his test, he said warning lights came on. He didn't say it shut off right? Unless it shuts off, I'm not going to worry too much about warning lights.

Thermal indicators should not come on when doing a basic test of a single pro amp on a test bench. What do you think is going to happen when you put multiples of these amps in a small rack and drive them at full power for hours?

You seem to be convinced the touring series Crown makes, which cost multiples of the low budget range, have no reason to exist and are just audio jewellery.

 

[AudioLover73]

No one knows what will happen because he didn't test it beyond the warning lights. The amp might have quit, or it might not. The only thing we know at this point is that a light came on. We shouldn't jump to any conclusions.

Thermal indicators should not come on when doing a basic test of a single pro amp on a test bench. What do you think is going to happen when you put multiples of these amps in a small rack and drive them at full power for hours?

 

[Geert]

 

[Frank207be]

Aren't sensitivity ratings for subwoofers usually of little value? They're usually taken at frequencies subwoofers would never be used at. In the description it says, "this driver is capable of 45.5 mm of excursion before any major loss in motor strength (Bl). In other words, this driver is capable of 90 mm (3.5") peak to peak excursion while still producing low distortion output." Now based on my research, I don't think I'll be able to achieve that kind of excursion but I'm hoping this means that this driver is significantly better engineered than what's out there, especially in this price range.

If I tune the enclosure to 16Hz, the excursion at 16Hz is 18mm at 3500W, peaking at 35mm at 22Hz. These seem like numbers I could live with.

But yes, it's relatively low in efficiency, but that's the tradeoff if you want low bass from a relatively small enclosure. It's either this driver in a 5.7 cu ft (160 L) enclosure (Peerless' own reference vented cabinet volume) or an Ultimax 18 in a 17 cu ft (480 L) enclosure. That's what I'm trying to decide between. But now that you mention other drivers, I'll have to look into them.

I'm very pleased to see someone here using large vented enclosures tuned to such low frequencies. Do you have a build thread on your subwoofers? I'd love to read about them. Is there anything you would change if you were to build them again?

I think the appeal of this subwoofer comes from how little space the finished product would occupy. It's either two full-size refrigerators or two relatively small cubes, and I'm willing to go with the refrigerators but maybe this will give me what I want. I just hope this Crown will drive it to a level I'm happy with. Sometimes I wonder if two SVS PB16-Ultras would satisfy my cravings for low bass.

The 45.5mm excursion limit makes way more sense with the physical appearance of that Peerless driver in mind but when you talk about feeding a single driver with 3500W remember that it'll put a lot of stress on all moving parts & glue joints. It’ll also become a challenge to prevent the relatively small enclosure from walking around

What’s the actual purpose of this build? Home theatre subwoofer in a living room?

My motivation to go with the large pro drivers was their relative affordability, their robust build, the air that’s moved with less excursion, the low self inductance which allows better integration in a music oriented system and thus possible higher crossover frequencies. I don’t have a build thread but rest assured that I’ve gone the extra mile to make the cabinets as stiff as possible with window & cross bracing and 36mm MDF thickness all around. The second purpose of these refrigerator size subs was providing clearance between the couch and the back wall which allows a 7 channel surround system done right. The 11Hz tuning on the dual B&C 21SW152 gives me single digit frequencies and a reasonably flat response from 15Hz to 100Hz with some EQ. The XLS2502 delivers enough power to allow a visceral movie experience. Any regret? No

Dual SVS PB16-Ultra certainly come at a cost. A well thought out DIY project will be much cheaper and can be built fit to size. For instance my dual RCF LF18N405 are integrated into a bedroom AV wall. Link: https://i.ibb.co/NCCYSCs/IMG-20200214-170944.jpg

 

[AudioLover73]

The primary purpose of this build is music enjoyment but I might watch movies on it too. I have a song I like that reaches 16Hz, so I figured I'd make it flat to 16Hz. I did a quick comparison of a few drivers at 1W in the image below. It looks like the UM18 has 5dB more output at 16Hz than the B&C but the B&C has impressive output at 10Hz. I also threw the UM18 in the B&C's enclosure to see how it would perform. The red traces are the UM18, the cyan is the Peerless, and the green is the B&C.

You make me want to lower my tuning frequency. I just checked the tuning frequency of my enclosure with one of the two 6" ports plugged, and it drops from 16Hz to 11Hz. Maybe I'll plug one of the ports when I watch movies.

Wow, that bedroom AV setup looks so nice! Are you using one or two of these amps with your B&Cs? They handle 4000 watts continuous right? Man that B&C is quite an impressive driver. I'm playing around with it in different box designs, and I'm trying to justify its cost.

The 45.5mm excursion limit makes way more sense with the physical appearance of that Peerless driver in mind but when you talk about feeding a single driver with 3500W remember that it'll put a lot of stress on all moving parts & glue joints. It’ll also become a challenge to prevent the relatively small enclosure from walking around

What’s the actual purpose of this build? Home theatre subwoofer in a living room?

My motivation to go with the large pro drivers was their relative affordability, their robust build, the air that’s moved with less excursion, the low self inductance which allows better integration in a music oriented system and thus possible higher crossover frequencies. I don’t have a build thread but rest assured that I’ve gone the extra mile to make the cabinets as stiff as possible with window & cross bracing and 36mm MDF thickness all around. The second purpose of these refrigerator size subs was providing clearance between the couch and the back wall which allows a 7 channel surround system done right. The 11Hz tuning on the dual B&C 21SW152 gives me single digit frequencies and a reasonably flat response from 15Hz to 100Hz with some EQ. The XLS2502 delivers enough power to allow a visceral movie experience. Any regret? No

Dual SVS PB16-Ultra certainly come at a cost. A well thought out DIY project will be much cheaper and can be built fit to size. For instance my dual RCF LF18N405 are integrated into a bedroom AV wall. Link: https://i.ibb.co/NCCYSCs/IMG-20200214-170944.jpg

 

[Frank207be]

The primary purpose of this build is music enjoyment but I might watch movies on it too. I have a song I like that reaches 16Hz, so I figured I'd make it flat to 16Hz. I did a quick comparison of a few drivers at 1W in the image below. It looks like the UM18 has 5dB more output at 16Hz than the B&C but the B&C has impressive output at 10Hz. I also threw the UM18 in the B&C's enclosure to see how it would perform. The red traces are the UM18, the cyan is the Peerless, and the green is the B&C.

You make me want to lower my tuning frequency. I just checked the tuning frequency of my enclosure with one of the two 6" ports plugged, and it drops from 16Hz to 11Hz. Maybe I'll plug one of the ports when I watch movies.

Wow, that bedroom AV setup looks so nice! Are you using one or two of these amps with your B&Cs? They handle 4000 watts continuous right? Man that B&C is quite an impressive driver. I'm playing around with it in different box designs, and I'm trying to justify its cost.



View attachment 114292

Always fun to play around in WinISD, isn't it? There are a lot of options available to get deep and deeper bass. After buying the driver comes the hardest part: spending hours building the enclosure(s). Here a picture from the carcass of one B&C sub: https://i.ibb.co/tmrrM7W/Subcarcass.jpg

The B&C 21SW152 can handle 2000W continuous and 4000W peak. At the moment I use one Crown XLS2502 bridged for both B&C in the living room and a second one for both RCF in the bedroom. Later on I might buy 2 more of these amps: one for each separate B&C sub and another for my front subwoofers (4x vintage Visaton TIW400 in separate sealed 130L boxes that are currently driven by one Hypex UCD700)

 

[hiroo]

I used to own this amp and I discovered with my own rudimentary testing that it has about a 1ms propagation delay from input to output.

I recently got some used Paradigm Studio 100v4 towers and have been pretty disappointed with the lack of bass (spec'ed down to 28Hz) from them compared with my previous decades-old Paradigm 11se's, which had great bass response even without the subwoofer on.

I'm running a Rotel RMB-1075 125Wx5 power amp, which I thought would be enough for these but I read a comment from a Paradigm corporate rep that the 100's needed at least 200W amps to get good bass response due to a dip down to 2 ohms in the bass region. I'm only using 3 channels of the Rotel currently (the 11se's didn't have separate input posts). Once I get around to rewiring everything, I was going to try bi-amping the 100v4's since I have two extra channels on the Rotel anyway, but I'm not sure using additional channels on the same amp would have a real benefit.

However, another option I was thinking was to get one of these Crown XLS pro-amps and run the woofer section of the 100v4's using the Crown and use the Rotel for the mids/tweeter to avoid the high freq harmonics on the Crown. But the comment quoted above about the 1ms delay on the Crown XLS seems like this would kill this idea since the delay between the woofers on the Crown and the mid/highs on the Rotel would be huge. Anybody know if this would be a real problem? Is it a generally bad idea to use two different types of amps on a single speaker?

 

[Frank207be]

I recently got some used Paradigm Studio 100v4 towers and have been pretty disappointed with the lack of bass (spec'ed down to 28Hz) from them compared with my previous decades-old Paradigm 11se's, which had great bass response even without the subwoofer on.

I'm running a Rotel RMB-1075 125Wx5 power amp, which I thought would be enough for these but I read a comment from a Paradigm corporate rep that the 100's needed at least 200W amps to get good bass response due to a dip down to 2 ohms in the bass region. I'm only using 3 channels of the Rotel currently (the 11se's didn't have separate input posts). Once I get around to rewiring everything, I was going to try bi-amping the 100v4's since I have two extra channels on the Rotel anyway, but I'm not sure using additional channels on the same amp would have a real benefit.

However, another option I was thinking was to get one of these Crown XLS pro-amps and run the woofer section of the 100v4's using the Crown and use the Rotel for the mids/tweeter to avoid the high freq harmonics on the Crown. But the comment quoted above about the 1ms delay on the Crown XLS seems like this would kill this idea since the delay between the woofers on the Crown and the mid/highs on the Rotel would be huge. Anybody know if this would be a real problem? Is it a generally bad idea to use two different types of amps on a single speaker?

I'd sell those speakers in a heartbeat. Dipping down to 2 Ohms is quite unforgivable IMHO and shows a severe lack of respect from the manufacturer towards (less informed?) consumers.

If you want to proceed with these Paradigm speakers, maybe try a used Crown XLS 1002 or 1502 and sell the amp if you don't like the result? The XLS 2502 could be overkill for these poor 7" woofers

 

[Alice of Old Vincennes]

I'd sell those speakers in a heartbeat. Dipping down to 2 Ohms is quite unforgivable IMHO and shows a severe lack of respect from the manufacturer towards (less informed?) consumers.

If you want to proceed with these Paradigm speakers, maybe try a used Crown XLS 1002 or 1502 and sell the amp if you don't like the result? The XLS 2502 could be overkill for these poor 7" woofers

At least the 1502.

 

[Dwander]

I have two of these amps, each bridged and powering a 24" subwoofer. They work well and the fans never turn on, even on really demanding movies.

I was reading this thread trying to find someone using this amp in this way. What drivers are you powering? Ive got two stereo integrity hst 18s being powered by a simbosen fp20000q. I love the amp but the heat is becoming an unmanageable problem, and I’m considering going to dual xls 2502 instead.

 

[LumbermanSVO]

I was reading this thread trying to find someone using this amp in this way. What drivers are you powering? Ive got two stereo integrity hst 18s being powered by a simbosen fp20000q. I love the amp but the heat is becoming an unmanageable problem, and I’m considering going to dual xls 2502 instead.

Each amp is powering a Stereo Integrity HS24. They work flawlessly, don't get hot, fans don't come on, and I have WAY more power than I need.

 

[Dwander]

Each amp is powering a Stereo Integrity HS24. They work flawlessly, don't get hot, fans don't come on, and I have WAY more power than I need.

I was hoping you the stereo integrity’s. My clone amp doesn’t even register with the lights on the front panel so I’m barely using any of its power. So the crown should also be more than enough. I wanted a one box solution for my current 2 subs and future plans for 2 more, but it’s not worth being uncomfortable for. I’m thinking I’ll probably go this route.
Thanks

 

[LumbermanSVO]

I thought about the clones, but there always seems to be someone having issues with them. You just don't hear about those issues with the Crowns. And I'm not so sure the clones really make all that much more power than the 2502, or at least enough to make a difference.

HS24 and Crown owners seem to have one thing in common: Once everything is running, you don't hear from them anymore. Why? Because you don't need to mess with it anymore.

 

[Dwander]

I thought about the clones, but there always seems to be someone having issues with them. You just don't hear about those issues with the Crowns. And I'm not so sure the clones really make all that much more power than the 2502, or at least enough to make a difference.

HS24 and Crown owners seem to have one thing in common: Once everything is running, you don't hear from them anymore. Why? Because you don't need to mess with it anymore.

Yea, with the clones i liked the idea of 4 channels in one chassis and I thought they were pretty cool amps. I knew about the noise they made with the fans but I didn’t expect this issue with the heat to be a problem. I think I’m going to pickup the crowns today

 

[Frank207be]

Yea, with the clones i liked the idea of 4 channels in one chassis and I thought they were pretty cool amps. I knew about the noise they made with the fans but I didn’t expect this issue with the heat to be a problem. I think I’m going to pickup the crowns today

I have one XLS2502 in my bedroom and after viewing an evening movie we just power off the TV+AVR with the remote control. The Crown usually stays on and we never wake up from the fan noise. In the morning when I'm getting up for work I usually power off the Crown after checking the case in the back where the PSU is located. Then I'm sure that my wife didn't power it off in the middle of the night during a bathroom visit

 

[Dwander]

I have one XLS2502 in my bedroom and after viewing an evening movie we just power off the TV+AVR with the remote control. The Crown usually stays on and we never wake up from the fan noise. In the morning when I'm getting up for work I usually power off the Crown after checking the case in the back where the PSU is located. Then I'm sure that my wife didn't power it off in the middle of the night during a bathroom visit

Nice. I have a sidelined 1002 that was using for different things for a while and don’t ever remember hearing the fan or seeing it come on. But with my rack location I can have some fan noise and not hear it so thats less of a concern for me. It was just the heat off my clone amp was insane. Couldn’t figure out why all of a sudden my room was so much warmer and more uncomfortable than before. You‘d think I would automatically assume it was the 18,000 watt Chinese knock off amplifier I just installed. I’m hoping all goes back to normal once I swap these crowns in.

 

[Head_Unit]

I was reading this thread trying to find someone using this amp in this way. What drivers are you powering? Ive got two stereo integrity hst 18s being powered by a simbosen fp20000q. I love the amp but the heat is becoming an unmanageable problem, and I’m considering going to dual xls 2502 instead.

Maybe this is relevant?

"We upgrade fp20000q amplifier successfully. The fp20000q amplifier temperature can be reduced by 15-20 ℃ when working. "
Also, note that heat in amps is related to current squared. So loading them down to very low impedances will output way more heat. So it could indeed be better to run two amps-maybe another fp20000q if you like it so much.

 

[Dwander]

Maybe this is relevant?

"We upgrade fp20000q amplifier successfully. The fp20000q amplifier temperature can be reduced by 15-20 ℃ when working. "
Also, note that heat in amps is related to current squared. So loading them down to very low impedances will output way more heat. So it could indeed be better to run two amps-maybe another fp20000q if you like it so much.

It’s possible but adding another one is a bit of a gamble. I already picked up the crowns and installed them so will do some testing this weekend to see what difference it makes.
Only issue now is that I’m pretty sure one of the amps was a open box return. Ive got nothing against open box but just not at full price. I’m going to call the store today and see if they will do anything.

 

[Dwander]

Each amp is powering a Stereo Integrity HS24. They work flawlessly, don't get hot, fans don't come on, and I have WAY more power than I need.

Problem solved. Watched Batman Begins and half the Dark Knight and the room stayed at a comfortable temperature the entire time. Much better experience. Thanks for the help!