Crown XLS2502 Stereo Amplifier Review

[dwkdnvr]

I own these as well and agree with everything you've said. I currently use them in the living room powered by a middling home theater receiver and they sound fantastic at SPLs that I could have never hit with less efficient speakers. I've also used them as PA speakers powered by a Crown amp and they didn't break a sweat. Truly the best deal in audio.

Further, I currently use said Crown amp to power 85dB efficient speakers in a nearfield setup and it sure sounds hi-fi to me. The power really makes the speakers come alive.

Interesting - I hadn't run across the BIC RTR EV-15s before. Given the price and the potential performance envelope, I'm surprised nobody seems to have cracked them open to do measurements and taken a shot at an upgraded xover - or even just detailed measurements to come up with a canonical EQ curve. I suspect some of this is that they're likely more appropriate in the HT space than the audio space and the typical Audyssey or equiv correction will handle at least some of it.
Might be tempting if I wasn't already overloaded/behind in projects.

 

[Severian]

Interesting - I hadn't run across the BIC RTR EV-15s before. Given the price and the potential performance envelope, I'm surprised nobody seems to have cracked them open to do measurements and taken a shot at an upgraded xover - or even just detailed measurements to come up with a canonical EQ curve. I suspect some of this is that they're likely more appropriate in the HT space than the audio space and the typical Audyssey or equiv correction will handle at least some of it.
Might be tempting if I wasn't already overloaded/behind in projects.

Yeah, I've always been surprised there isn't more interest. I've seen some dissection photos but no talk of upgrading the crossover. I'm not sure there's anything wrong with the crossover though..

I have them crudely EQ'd with my receiver for a "house curve" with about a 6dB slope. Out of the box they are slightly bright for my taste (the high frequency driver surely being the weak link quality-wise) and I wanted a bass boost because part of my purpose in buying the speakers was obviating the need for subwoofers in my living room. One of these days I will measure them (until a few weeks ago I didn't have a Windows laptop to run REW in my living room) and I also plan on adding a DSP and external power amps.

One huge benefit to using these instead of smaller speakers and subwoofers is that I don't have to fight the receiver's bass management for two channel music like I've had to do in the past with subwoofers.

 

[Trdat]

I would recommend everybody listening to a system with high efficiency (90+ dB/watt, ideally 95+) speakers and/or a high-output amp like this, if you ever get the chance.

Once you have heard a system that achieves that, it will change the way you look at audio.

It's not about hitting massive SPL output levels. (Although that's obviously fun too, for brief periods of time)

It's about sounding "effortless" - handling every dynamic peak in your music without audible distortion. Even at moderate listening levels, this is very pleasing to the ear.

I went from Bookshelf PSB Imagine XB to a Troel DIY Design 3 way and after years of understanding about speakers I have come to the conclusion that the next step up is a PA style efficient speaker. And after just reading your comment i'm now driven to this goal of efficient and large woofer type speakers that can handle dynamics and peaks.

 

[JMM]

I am surprised to see this amp tested here. As far as I know their market is primarily DJs and live sound reinforcement. They have similar but different goals than home stereo users.

I own the Crown XLS 1002 and use it in bridged mono for an electric bass amp. You need a lot of power for a bass amp and ideally I can provide it with low weight because I have to carry it myself. This amp does that really well. It needs to sound “good enough” and it also does that quite well.

 

[DonH56]

I am surprised to see this amp tested here. As far as I know their market is primarily DJs and live sound reinforcement. They have similar but different goals than home stereo users.

I own the Crown XLS 1002 and use it in bridged mono for an electric bass amp. You need a lot of power for a bass amp and ideally I can provide it with low weight because I have to carry it myself. This amp does that really well. It needs to sound “good enough” and it also does that quite well.

A significant number of audiophiles, at least if you believe the various audio fora are representative, purchase these and other "pro" sound reinforcement amplifiers due to their low cost per watt. They are a popular choice among DIY subwoofer builders as well. Crown must have picked up on that because they have a made a few changes/feature adds in recent years that appear to target the consumer audio market.

 

[JohnBooty]

Yeah, I've always been surprised there isn't more interest. I've seen some dissection photos but no talk of upgrading the crossover. I'm not sure there's anything wrong with the crossover though..

I have them crudely EQ'd with my receiver for a "house curve" with about a 6dB slope. Out of the box they are slightly bright for my taste (the high frequency driver surely being the weak link quality-wise) and I wanted a bass boost because part of my purpose in buying the speakers was obviating the need for subwoofers in my living room.

Great to hear from other fans. Helps me feel a little less crazy. I definitely don't feel the need for subwoofers with these! Initially I used them with an HK3390 (85W into 8ohm) and thought the bass was very capable. I thought the bass took another step forward with the XLS amp.

Have you tried raising or tilting them up somehow? One thing I found very beneficial was to get them off of the ground a little. This seemed to clean up the bass. I can only assume there was some ground bounce going on. Because they're in my garage (20' by 20' or so) aesthetics are not a concern, so they're currently sitting on milk crates.

I agree with you. The tweeter is probably would I would call the weak link. It's not bad by any means, in my opinion. But, not the star of the show.

One of these days I will measure them (until a few weeks ago I didn't have a Windows laptop to run REW in my living room) and I also plan on adding a DSP and external power amps.

One huge benefit to using these instead of smaller speakers and subwoofers is that I don't have to fight the receiver's bass management for two channel music like I've had to do in the past with subwoofers.

Yeah, it's funny how many problems (subwoofer placement, bass management, tons of other factors related to speaker design, etc) somewhat melt away when simply using speaker cabinets of appropriate (large) volume to produce some bass.

So many complications in modern home sound equipment are a result of the fact that everybody's trying to wring some decent bass out of boxes that are as small as possible.

I suspect some of this is that they're likely more appropriate in the HT space than the audio space and the typical Audyssey or equiv correction will handle at least some of it.

They are very appropriate for music!

 

[b1daly]

I’m curious as to why the consensus on this site, anecdotally speaking, seems to be that high powered amps are important enough to merit the extra cost? Unless you have a big room, or very inefficient speakers, most people shouldn’t need more than 60wpc. That is enough to drive your average speaker to unpleasantly loud volumes that are dangerous to your ears for sustained listening.

Most modern music has limited dynamic range, and simply does not generate large peaks in volume anyway, negating the need for high headroom amplification.

Most "pop" (considered very broadly) recordings are engineered to “sound loud” at low volumes, and the crazy amount of processing involved in this often introduces distortions which are unpleasant at loud volumes. It also results in a dynamically compressed signal which will stress your ears that much more at high levels. (Because you are subjecting yourself to more total sound energy on average).

If you really are a fan of orchestral music recorded with minimal dynamic compression, and you want to listen at near concert levels, then perhaps you need a lot of power, if your listening room is big enough to allow for a sizable distance to speakers (over 15 ft). This represents a vanishingly small audience. Most "classical" music recordings are compressed anyway, though not as much as a typical pop production.

A lot of people think "dynamic range" is a good thing in music, but in most cases it simply has to be controlled to make effective recordings for the "real world." Only the very best audio systems can come close to reproducing the full dynamic range of an orchestra.

There is a paradoxical aspect to dynamic range compression, which is that it usually makes things sound "louder" relative to anything else (like background noise). So compression can make things actually feel more "dynamic". There are a couple of aspects to this, but functionally it pulls quiet passages into a more audible range, and allows us to hear the dynamics of sections of music which might fall to low into the ambient noise.

The other factor which allows dynamically compressed recordings to deliver an experience that still feels dynamic, is that our ears are not that sensitive to dynamic level changes, but are very sensitive to timbre changes. Timbre communicates the bulk of the perceptual qualities of dynamic passages. Compression allows for more perception of timbre overall.

As an example of this overall issue, anyone that likes to watch TV with a decent playback system has probably noticed an annoying experience where within a program, or between programs, there are significant level changes.

Say a car chase scene comes on, with pounding music. If you had the level loud enough to where the dialog was clear, these passages of louder music, which are themselves heavily compressed (relatively speaking) will "wear your ears out" quickly, and you will find yourself reaching for the volume knob too much. Some AVRs are attempting to address this by building dynamic compression into the amp itself! (There are a lot of different types of compression.)

When it comes to useful standards, what I think we need are carefully constructed standards based on reproducible, double blinded, audibility testing. (Probably ABX is the most practical.) With a set of a standard tracks and speakers. New speakers and test tracks could be introduced over time, using the same testing methodology, and the results interpolated into the existing reference data. Testing for sound for video should be included as well.

Amps tested under this method could then be tested on the bench, and the results correlated with the listening tests. Listening testing is terribly hard and expensive, but my guess would be it would be well correlated with bench tests, allowing for practical testing of a wide range of products.

This is the basis of the speaker testing Floyd Toole and colleagues did. Without this careful listening tests, the results are not as useful. Once some baselines of audible performance have been established, it would free consumers to focus on more practical questions related to reliability, features, aesthetics, and of course, price.

 

[anmpr1]

I’m curious as to why the consensus on this site, anecdotally speaking, seems to be that high powered amps are important enough to merit the extra cost? Unless you have a big room, or very inefficient speakers, most people shouldn’t need more than 60wpc. That is enough to drive your average speaker to unpleasantly loud volumes that are dangerous to your ears for sustained listening.

A) There is not much 'extra cost' to a Crown amp. That is it's big selling point.

B) Some people do have 'big rooms'.

C) Some full range 'audiophile' speakers require more than 60 watts (along with a lot of current). Some don't.

D) If your speakers have very low distortion (as far as speakers go) it is possible to listen at ear damaging levels and not be aware of the fact. It is usually speaker distortion, and not loudness per se, that makes you turn your volume control down.

 

[DonH56]

There are a lot of relatively insensitive 4-ohm'ish speakers these days. I suspect that with abundant amplifier power speaker designers focus on other things than high sensitivity. A pair of 85 dB/W/m speakers eight feet away needs 200 W to reach 100 dB peaks, which readily happens at an average level of maybe 80 to 83 dB (loud listening). The equation is independent of frequency so works as well at 1 kHz as 100 Hz.

Listener fatigue due to clipping is a real thing, especially since clipping sprays harmonics across the audio spectrum. As @anmpr1 said it is very common for listeners to have average SPL louder than they think when the system is not distorting. It sounds good and mot uncomfortable because there is enough power to avoid clipping and low enough distortion.

Ask Floyd what amplifiers he has (or check out his system -- it is posted at several places online).

A lot of music has very deep bass, though it may be at a low level. Subharmonic tones are created when musicians play together, there are percussives from drums, plucked strings, piano hammer strikes, etc. Doesn't have to be organ music to generate signals at and below 20 Hz.

Onwards - Don

 

[Willem]

I like classical music and relatively dynamic recordings, and I don't think I am a vanishingly small minority - I certainly hope not. I have two sets of speakers: Harbeth P3ESRs in my 20 sq m study, and Quad 2805 electrostats (plus a B&W PV1d sub) in the 65 sq m living room. Both Harbeth P3 and Quad 2805 speakers have a sensitivity of around 83 dB.

 

[anmpr1]

I like classical music and relatively dynamic recordings, and I don't think I am a vanishingly small minority - I certainly hope not. I have two sets of speakers: Harbeth P3ESRs in my 20 sq m study, and Quad 2805 electrostats (plus a B&W PV1d sub) in the 65 sq m living room. Both Harbeth P3 and Quad 2805 speakers have a sensitivity of around 83 dB.

My anecdote: Listening to original Quads was nice, but I longed for a louder sound. I bought Acoustats, that were in no way sonically better than the Quad, but played louder. However, then I had to get a huge amp to take advantage of the SPL because my 405 didn't have enough huff. So I spent more money, but actually had less 'quality' sound. But it was louder!

 

[Willem]

The 2805s play louder than my old 57s, and go deeper. But they like more juice. So I replaced my 2x45 watt Quad 303 with a 2x140 watt 606-2.

 

[HammerSandwich]

@b1daly, asking why ASR members recommend powerful amps in light of modern, mass-market recordings is akin to asking why they recommend Kii & Revel when most people are happy with a soundbar. Condense your post to its essence, and the answer becomes clear:

This site represents a vanishingly small audience.

 

[dwkdnvr]

They are very appropriate for music!

I don't doubt it - my point was just that most 'music only' people aren't going to look at this type of speaker by default. The (lack of) aesthetics and high output capability are more likely to attract HT oriented folks like you find at avsforum.

The best sounding system I've ever had is still my Yorkville U15's. I had them tucked into the corners of a really tiny room. The narrow 60 degree directivity of the horn broadened to 90 due to the corner, and so provided surprisingly uniform sound. Some treatment at the 1st reflection points and brute-force EQ in the form of drc-fir basically turned them into giant headphones that had effectively infinite headroom.

This system is the one that makes me appreciate the idea that maybe we really do need more power and efficiency than typical 'audiophile' setups provide. It's not the ability to play loud that mattered - it was the snap and bite of transients without having to jack the treble into fatiguing territory. I had them voiced a bit dark if anything, but the transient attack was still there. But, they still handled all the delicate detail well too. I unfortunately had to sell them since I couldn't afford to continue to dedicate the room to them, which was painfully ironic since we later moved into a much larger house where I could have easily absorbed them into our HT space.

It's on the recording rather than playback side, but I remember Tom Danley doing some experiments trying to determine how much headroom was needed to capture truly uncompressed source material and it was ridiculously high. Dropping a fork needed something like 120dB capability to capture without clipping. Obviously playback systems only need to handle whatever the source system managed to capture, but it certainly was eye-opening.

 

[anmpr1]

Dropping a fork needed something like 120dB capability to capture without clipping. Obviously playback systems only need to handle whatever the source system managed to capture, but it certainly was eye-opening.

Classical recording engineer Max Wilcox argued for peak limiting, saying that it was better to limit high energy transients than to overload the tape, or alternately to record at an overall lower level. Of course he made this statement (1977) during the heyday of analog tape--I think at that time the Soundstream recorder was out, along with Sony and Denon machines... probably a few others. But they were not ubiquitous.

 

[JohnBooty]

It's not the ability to play loud that mattered - it was the snap and bite of transients without having to jack the treble into fatiguing territory.

Yeah I wish this was more widely experienced. It's not the only thing that's important, of course, but once you'd heard it, it's something you value. For speakers to approach the impact of live instruments I think it's a must.

 

[b1daly]

There are a lot of relatively insensitive 4-ohm'ish speakers these days. I suspect that with abundant amplifier power speaker designers focus on other things than high sensitivity. A pair of 85 dB/W/m speakers eight feet away needs 200 W to reach 100 dB peaks, which readily happens at an average level of maybe 80 to 83 dB (loud listening). The equation is independent of frequency so works as well at 1 kHz as 100 Hz.

Listener fatigue due to clipping is a real thing, especially since clipping sprays harmonics across the audio spectrum. As @anmpr1 said it is very common for listeners to have average SPL louder than they think when the system is not distorting. It sounds good and mot uncomfortable because there is enough power to avoid clipping and low enough distortion.

Onwards - Don

Most recordings playing at an average level of 80 db will not get above 90 db peaks (due to hard limiting of the signal).

My intuition is that few people drive their amps close to clipping. But a lot of people feel like a more powerful amp still sounds better than a similar amp with less power, even though both are operating within their specified power limits.

Maybe some of the amp gurus posting here could comment on whether dynamic signals benefit from more powerful amplifiers if they are being operated under clipping? Do dynamic signals really need more power than steady state to be driven to a certain level?

 

[DonH56]

Most recordings playing at an average level of 80 db will not get above 90 db peaks (due to hard limiting of the signal).

My intuition is that few people drive their amps close to clipping. But a lot of people feel like a more powerful amp still sounds better than a similar amp with less power, even though both are operating within their specified power limits.

Maybe some of the amp gurus posting here could comment on whether dynamic signals benefit from more powerful amplifiers if they are being operated under clipping? Do dynamic signals really need more power than steady state to be driven to a certain level?

Depends on the recording, of course... Do you have data? I don't, just what I remember from old AES papers and more recently reports on various audio fora, plus a vague memory of my previous measurements. 10 dB is not a lot of dynamic range, but then again that's the world we live in these days. I listen to a lot of jazz and some classical and I'm pretty certain soft to loud swings are more than 10 dB (half loudness).

This does not make sense to me: "Do dynamic signals really need more power than steady state to be driven to a certain level?" To reach a certain level you need the power to get there whether steady-state or "dynamic" peaks. Peaks may not last long so many amplifiers can handle short-term peaks about their rated power without clipping. This used to be specified as "dynamic headroom" and there was a standard test for it (a 20 ms burst IIRC). I do not see that much anymore, not sure why. For a while dynamic headroom was a selling point, with Bryston and NAD coming to mind as having 3-6 dB headroom per spec.

Power-wise, there's not much argument for having much greater than you need. It is worth noting that 3 dB is a relatively small amount of headroom SPL-wise but requires twice the power so there is a decent rationale for decent power reserves. HIgher-power amplifiers also tend to have lower output impedance so do better driving real-world speaker loads (the amps are closer to an ideal voltage source) and higher standing bias current so stay in class A longer (lower crossover distortion, though that is pretty much a solved problem). Too much power has drawbacks, natch, including higher energy costs (electric bill), more heat, potentially more hiss, etc.

I calculated what I expected to need to hit 105 dB SPL since that was THX reference level with a little margin and called it good. I rarely listen that loudly but the kids visit now and then...

 

[RayDunzl]

Most recordings playing at an average level of 80 db will not get above 90 db peaks (due to hard limiting of the signal).

My experience here usually puts the peaks at 15 to 20dB over the Leq, with a UMIK-1 and REW in use for measurement.

 

[b1daly]

Depends on the recording, of course... Do you have data? I don't, just what I remember from old AES papers and more recently reports on various audio fora, plus a vague memory of my previous measurements. 10 dB is not a lot of dynamic range, but then again that's the world we live in these days. I listen to a lot of jazz and some classical and I'm pretty certain soft to loud swings are more than 10 dB (half loudness).

This does not make sense to me: "Do dynamic signals really need more power than steady state to be driven to a certain level?" To reach a certain level you need the power to get there whether steady-state or "dynamic" peaks. Peaks may not last long so many amplifiers can handle short-term peaks about their rated power without clipping. This used to be specified as "dynamic headroom" and there was a standard test for it (a 20 ms burst IIRC). I do not see that much anymore, not sure why. For a while dynamic headroom was a selling point, with Bryston and NAD coming to mind as having 3-6 dB headroom per spec.

Power-wise, there's not much argument for having much greater than you need. It is worth noting that 3 dB is a relatively small amount of headroom SPL-wise but requires twice the power so there is a decent rationale for decent power reserves. HIgher-power amplifiers also tend to have lower output impedance so do better driving real-world speaker loads (the amps are closer to an ideal voltage source) and higher standing bias current so stay in class A longer (lower crossover distortion, though that is pretty much a solved problem). Too much power has drawbacks, natch, including higher energy costs (electric bill), more heat, potentially more hiss, etc.

I calculated what I expected to need to hit 105 dB SPL since that was THX reference level with a little margin and called it good. I rarely listen that loudly but the kids visit now and then...

Actually, I think you might be right. I've been checking on my cheap SPL meter. What I consider a loudish listening level, the readings will be averaging between 80-84 dB, with it rarely getting into the 90s. The problem is that this is A weighted, (so the unit should be dB(A)).

After looking into it, I've learned A weighting rolls off low frequencies.

I found an app for my iPad which will give measurements for instantaneous/peak measurements in both A and C weighting. C weighting is much closer to a flat frequency response, which I think is what is relevant for thinking about needed power for an amp.

The app A weighting measurement is spot on with my SPL meter...but when I have an average listening level of about 82 in A weighting, the A peaks won't get much above 90dB(A) but the C weighting goes well above 100dB(C) on peaks!

What's weird is that my amp (Kenwood KA-5500) has VU power level meters and at such a level they barely peak above 1 watt. VU meters are an averaging meter, but I find it hard to believe the amp is being driven in to clipping when these meters are down in the low part of their range. The meters have a low level setting, when put on the high level setting, which shows full scale up to 55 watts, the meters are barely moving.

Is it possible the amp is being "asked" to put out 200 watts on the peaks? (It's rated at 55 wpc). I'm not hearing any clipping. Perhaps the amp is doing some kind of "soft clipping?"

I'm listening on ADS L710, which have a given sensitivity of "92 db SPL at 1 watt RMS input at 1 meter." This seems roughly close to what I'm "ballpark" measuring.

It's a complicated subject. There is no exact specification for this concept, as it's dependent on the duration and shape of the measuring "window", the duration of the measurement, and the characteristics of the signal.

A simple approximation of "effective dynamic range" is the "crest factor"of a signal, which is the ratio of the peak level to the RMS average level.

This excellent article has an in depth discussion, and finds that the crest factor of most recordings is between 12-18 dB.

https://www.soundonsound.com/sound-advice/dynamic-range-loudness-war

The more relevant issue to this discussion is how we conceive of the "loudness" of a signal, which includes both average and peak levels, and how much demand our desired average listening puts upon our amplifier.