Thoughts on Reaction Audio?

[rojo]

For the record, when I say PSA is the best value "for music", it is an acknowledgement that they are not as strong for deep bass LFE at high output as some subs. They maintain composure, but they are not designed for the kind of strong subsonic reproduction that makes great LFE/HT.

You're describing a pretty typical characteristic of sealed subs. You did say your PSA subs were sealed, right? It should be noted that PSA also offers ported subs, which wouldn't suffer the same need for such qualification.

 

[theJman]

It's not perfect, but neither is it useless.

"flawed methodology" <> "useless". You're confusing two different things. I never said useless because I don't believe CEA-2010 is without merit. It's just not the panacea some make it out to be.

 

[rojo]

"flawed methodology" <> "useless". You're confusing two different things. I never said useless because I don't believe CEA-2010 is without merit. It's just not the panacea some make it out to be.

I think I understand what you're saying. CEA-2010 gives no indication of deviation of out-of-spec drivers, amps, stuffing, enclosures, temperature, humidity, air pressure, long-term compression, thermal changes in the voice coil, port resonance, standing waves, and the list goes on forever. It's only offered as a baseline estimate that could be disrupted by a butterfly's wings on the other side of the planet, and surgical precision can never be achieved. You view shadyJ's claims of PSA's measurement comparisons' being more marketing than science, as unreasonable, hyper-critical, obsessing over minutiae which may vary from one environment to the next, one sample to the next, one measurement to the next. And shadyJ should get off your lawn. Is this what you're saying?

I neither agree nor disagree, nor judge, nor praise or criticize. I just want to make sure I understand.

 

[KEW]

You're describing a pretty typical characteristic of sealed subs. You did say your PSA subs were sealed, right? It should be noted that PSA also offers ported subs, which wouldn't suffer the same need for such qualification.

Yes, my subs are sealed. While I suspect the ported PSA sub may be as clean for music, I have not heard them so cannot speak to them, but you are right that the PSA ported subs likely have the ability to produce low and loud for LFE/HT.
As far as typical characteristics of sealed subs, the SVS SB-12 plus and the JL Audio E112 did not have the characteristics that make the Rythmik and PSA my favorites. I suspect the issue is in the attempt to reproduce 20Hz loudly in an anechoic chamber (which both the SB12 plus and E112 try to do) there are compromises in the transient response. Frankly having an anechoically flat FR down to 20Hz is a very poor objective given what we know about room gain! Ricci mentions this in his review of the XS15se (which is my PSA sub) when he says the roll-off of the sub will likely be a good fit once room gain is considered:

The ground plane measurements for the Powersound XS-15SE are quite good for an $800 sealed system. The basic frequency response shape with the low pass filter bypassed shows a response that is cleanly extended up to 200Hz and beyond, with a gently sloping low end that corners at 30Hz and appears to enter a sealed systems natural 12dB/octave roll off below that point. It should be a good match with the boost often seen in the low bass once placed in room.

Ricci's conclusion:

The XS-15SE offers a lot of bang for the dollar. The driver is a high quality piece in this price range and the enclosure and finish is heavy duty. The engineering and DSP settings also seem to be well applied and thought out. It is one of the few, sealed design, powered subwoofers offered for under $1000 that is both engineered well and has enough headroom for a decent sized room. Based on the measurements and performance metrics alone it compares quite well to other commercial sealed subwoofers at 2x to 3x the price.

And with the XS15se at $800 when this review was written, I would put the JL Audio as one of those "commercial sealed subwoofers at 2x to 3x the price" that it compares quite well to!

PS - Note that the engineering of the PSA sub is complemented twice here.

 

[shadyJ]

Assuming I don't understand CEA-2010 testing is ignorance at its most visible. To be completely honest, I think there's far too much emphasis given on what's essentially a flawed methodology. Yes, it provides a baseline for a few aspects of performance, but is it accurate enough for everyone to use as the gold standard? No. Its primary component is total output, and in the process it glosses over far too many other aspects. In spite of that, you have nothing quantifiable to legitimately assert PSA's charts are a "bunch of lies". That's nothing more than BS from someone with an axe to grind.

So you think CEA-2010 is not a good standard by which to compare subwoofers, but you think PSA comparison charts are OK? What? If you want to see how PSA comparison charts are misleading, go look up third party measurements for PSA subs and compare them to PSA's own measurements. I have done this and demonstrated the problems with their charts on multiple occasions. A handful of those posts were actually deleted from AVSforum, even though there is no name-calling in them, no vitriol, just a factual comparison and analysis. Do your homework.

 

[shadyJ]

What I do know is there is no standardized measurement for subwoofers.

Lol, that is exactly what CEA-2010 is supposed to be, a standardized measurement for subwoofers!

Pick one measurement and have everyone do it. Right now its data-bass since Ricci is above reproach. Oem's like HSU publish figures taken at 1m when everyone else does at 2m, some use CEA, some don't, the whole thing is a mess. I can't fault Tom V for his charts, they are better than nothing and no one has shown they are wrong.

The standard is pretty strictly defined. One of the problems is everyone has their own versions of it. Also, multiple versions of the standard exists on top of that! - there is CEA-2010, CEA-2010-A, and CEA-2010-B. The only tester who strictly adheres to the standard is Brent Butterworth. There is also a lot of loose variables even in the individual standards which produces a pretty significant margin of error. PSA takes advantage of this variability to give them impression his subs are x times better than the competition, and in may cases the opposite is true, so yes, you can fault Tom for his charts; they are not better than nothing because they are misleading, and, as I said, I have shown as such on multiple occasions. It looks like I will have to do so again for this thread, but it's a tedious process- you have to take all the available numbers, convert them from dB to Pa, then average them, and then compare them. The problem is, I have done this before, but all that work is just dismissed by detractors because "shady just has an axe to grind".

 

[shadyJ]

CEA-2010 gives no indication of deviation of out-of-spec drivers, amps, stuffing, enclosures, temperature, humidity, air pressure, long-term compression, thermal changes in the voice coil, port resonance, standing waves, and the list goes on forever. It's only offered as a baseline estimate that could be disrupted by a butterfly's wings on the other side of the planet, and surgical precision can never be achieved.

Actually CEA does specify atmospheric conditions, at least for humidity and temperature. The range is 63° f to 80° f, and 30% to 80% relative humidity. I think CEA-2010-B even specifies compensation for altitude? Anyway, testing in lower temperatures can give higher measurements, because thermal compression does effect the test results.

 

[rojo]

It looks like I will have to do so again for this thread, but it's a tedious process- you have to take all the available numbers, convert them from dB to Pa, then average them, and then compare them.

IIRC, I think Butterworth has an Excel spreadsheet that performs this conversion linked from his CEA-2010 how-to page. If you're interested I can try to find it next time I'm at a PC.

 

[shadyJ]

IIRC, I think Butterworth has an Excel spreadsheet that performs this conversion linked from his CEA-2010 how-to page. If you're interested I can try to find it next time I'm at a PC.

No thanks, I can certainly do it myself, the question is do I want to send all that time collecting the numbers and running them through a spreadsheet again.

 

[theJman]

I think I understand what you're saying. CEA-2010 gives no indication of deviation of out-of-spec drivers, amps, stuffing, enclosures, temperature, humidity, air pressure, long-term compression, thermal changes in the voice coil, port resonance, standing waves, and the list goes on forever. It's only offered as a baseline estimate that could be disrupted by a butterfly's wings on the other side of the planet, and surgical precision can never be achieved. You view shadyJ's claims of PSA's measurement comparisons' being more marketing than science, as unreasonable, hyper-critical, obsessing over minutiae which may vary from one environment to the next, one sample to the next, one measurement to the next. And shadyJ should get off your lawn. Is this what you're saying?

I neither agree nor disagree, nor judge, nor praise or criticize. I just want to make sure I understand.

No really sure I can help you understand because I really can't decipher what any of that means. Bottom line is CEA-2010 is a subset of what a person should use as a decision making tool. In far too many cases it's used as the holy grail, when in reality it omits significant information. It's like judging a car based solely upon 0-60 results, skipad numbers and slalom time. It's certainly good to know, but it's definitely not all you need to know.

 

[theJman]

So you think CEA-2010 is not a good standard by which to compare subwoofers, but you think PSA comparison charts are OK? What? If you want to see how PSA comparison charts are misleading, go look up third party measurements for PSA subs and compare them to PSA's own measurements. I have done this and demonstrated the problems with their charts on multiple occasions. A handful of those posts were actually deleted from AVSforum, even though there is no name-calling in them, no vitriol, just a factual comparison and analysis. Do your homework.

Do you actually read anything posted, or do you just make stuff up as you go along?

I said CEA-2010 is a flawed methodology, in that the things it tests are not complete picture. Those who would use it as the sole reason to buy something are doing themselves a disservice. It might be the best system currently available, but it's still flawed. That's painfully obvious.

 

[rojo]

No really sure I can help you understand because I really can't decipher what any of that means. Bottom line is CEA-2010 is a subset of what a person should use as a decision making tool. In far too many cases it's used as the holy grail, when in reality it omits significant information. It's like judging a car based solely upon 0-60 results, skipad numbers and slalom time. It's certainly good to know, but it's definitely not all you need to know.

Thanks for responding. Ok, maybe I don't understand as well as I thought. There will never be, can never be a measurement standard that doesn't omit something. How can acoustic tests determine whether a particular model of sub is prone to popping capacitors in its amp, for example? No one is disagreeing with you that there's no such thing as a panacea in subwoofer measurement methodology.

I say that to point out that you seem to be spending a lot of unnecessary energy criticizing CEA-2010's incompleteness. I'm just having trouble connecting that with your disagreement with shadyJ.

 

[theJman]

Thanks for responding. Ok, maybe I don't understand as well as I thought. There will never be, can never be a measurement standard that doesn't omit something. How can acoustic tests determine whether a particular model of sub is prone to popping capacitors in its amp, for example? No one is disagreeing with you that there's no such thing as a panacea in subwoofer measurement methodology.

I say that to point out that you seem to be spending a lot of unnecessary energy criticizing CEA-2010's incompleteness. I'm just having trouble connecting that with your disagreement with shadyJ.

My sentiments against shady are not at all related to CEA-2010 measurements. That goes back much further. It just so happened he went off on his typical "PSA sucks" rant, trying to relate them to another company that will most likely go down in the annals of ID history as one of the worst. The two organization couldn't possibly be any more diametrically opposed, and all but one knows that.

I agree there's probably no way to create an all-encompassing method of testing subwoofers that would completely level the playing field, so CEA-2010 is all there is for the moment. My concern is twofold; there are several critical elements missing - ones KEW mentioned earlier - along with a general misconception that the results are the only thing necessary (save esthetics) to make a decision by. It seems to focus on measurements that indicate total output over almost all other attributes, and in that regard it comes up short for those wanting a more thorough understanding of capabilities. Something more along the lines of what Josh does should be adopted industry wide, because from his metrics a much clearly picture can be derived. It's stale and in need of an update.

 

[Steve81]

It seems to focus on measurements that indicate total output over almost all other attributes, and in that regard it comes up short for those wanting a more thorough understanding of capabilities.

I think that in part is shadyj's gripe with respect to the "PSA Output Factor" in comparing with subwoofers from other manufactuers, i.e. the PSA Output Factor saying how many competitor subs you'd need to equal a PSA subwoofer. Such a statement ignores other aspects of performance.

Further to shady's point, the output itself isn't some static thing; it changes based on the conditions of the test. Even if you tested the exact same sub, you'd get different results testing on a sunny, humid 85 degree summer day, versus a dry, 65 degree fall day. On the latter day, the air is denser, the system itself will be running a bit cooler (important for components like amplifiers), etc., which can result in a bit more output relative to the summer day. Ordinarily, no big deal. You and I know that 1-2dB doesn't amount to much in real terms, and that these tests have some variability. OTOH, when one looks at the PSA Output Factor, which is derived from Pa, that 1-2dB difference results in a score from 1.1 to 1.3. For a relatively uninformed buyer, that may be significant.

 

[mtrycrafts]

... You and I know that 1-2dB doesn't amount to much in real terms,...

Especially in the low frequency band. JND is more than that amount.

 

[KEW]

I think that in part is shadyj's gripe with respect to the "PSA Output Factor" in comparing with subwoofers from other manufactuers, i.e. the PSA Output Factor saying how many competitor subs you'd need to equal a PSA subwoofer. Such a statement ignores other aspects of performance.

Further to shady's point, the output itself isn't some static thing; it changes based on the conditions of the test. Even if you tested the exact same sub, you'd get different results testing on a sunny, humid 85 degree summer day, versus a dry, 65 degree fall day. On the latter day, the air is denser, the system itself will be running a bit cooler (important for components like amplifiers), etc., which can result in a bit more output relative to the summer day. Ordinarily, no big deal. You and I know that 1-2dB doesn't amount to much in real terms, and that these tests have some variability. OTOH, when one looks at the PSA Output Factor, which is derived from Pa, that 1-2dB difference results in a score from 1.1 to 1.3. For a relatively uninformed buyer, that may be significant.

I am completely comfortable with this point that Shadyj makes. I do believe PSA is playing with the numbers to put there subs in the best light and there may be some liberties taken along the way that do not reflect the highest ethics.

What I am not comfortable with is when he declares that PSA subs are poorly designed and should not be seriously considered by anyone who wants a decent sub. This is not consistent with my experience or Josh Ricci's comments.

 

[Steve81]

What I am not comfortable with is when he declares that PSA subs are poorly designed and should not be seriously considered by anyone who wants a decent sub.

Agreed. I was quite impressed with the bench test results of the XS15SE. If I happen to find myself needing a new sub sometime down the road, a couple S3000i's would be on my short list.

 

[shadyJ]

Especially in the low frequency band. JND is more than that amount.

The interesting thing about this is the JNDs of bass depends on sound pressure levels. The differences that can be heard in low frequencies can be finer than bands which our ears are most sensitive, 1 kHz to 4 kHz. Look how the lines of the equal loudness curves bunch up in the lows:

In many other ways our hearing in low frequencies is much worse than higher frequencies, but at the point where we start to hear low frequencies, our ability to distinguish differences in sound pressure is actually quite good.

 

[theJman]

I think that in part is shadyj's gripe with respect to the "PSA Output Factor" in comparing with subwoofers from other manufactuers, i.e. the PSA Output Factor saying how many competitor subs you'd need to equal a PSA subwoofer. Such a statement ignores other aspects of performance.

Further to shady's point, the output itself isn't some static thing; it changes based on the conditions of the test. Even if you tested the exact same sub, you'd get different results testing on a sunny, humid 85 degree summer day, versus a dry, 65 degree fall day. On the latter day, the air is denser, the system itself will be running a bit cooler (important for components like amplifiers), etc., which can result in a bit more output relative to the summer day. Ordinarily, no big deal. You and I know that 1-2dB doesn't amount to much in real terms, and that these tests have some variability. OTOH, when one looks at the PSA Output Factor, which is derived from Pa, that 1-2dB difference results in a score from 1.1 to 1.3. For a relatively uninformed buyer, that may be significant.

Based upon past history it's pretty obvious shady's comments about PSA are more personal than anything else - I mean comparing them to RA of all things? - but if I'm being completely honest I'm not a really big fan of that PSA Output Factor myself. I understand the notion of what they were trying to achieve - because there are soooo many bench racers out there, and it appears PSA was catering to those folks - but I can't say their execution of the concept really had the intended affect.

With regards to environmental variations impacting the results... I agree with you completely. Temperature, humidity and even something seemingly innocuous as direct/indirect sunlight will alter groundplane results. I think CEA-2010 covers less than half of what someone needs to know from an objective standpoint, which is why I keep saying it's a flawed methodology. Perhaps it would be better stated as an "incomplete" one instead, but in the end most of us know exactly what I'm talking about; it's definitely good info to have, but it's by no means a complete picture.

 

[Defcon]

I couldn't care less about 'output factor' or 1-3dB differences in SPL, no one is going to notice that in real life, its only used for forum arguments.

I care a lot more for things like using modern amps vs a BASH design, better DSP controls etc, in those respects PSA and SVS are on top, HSU still uses their old amps and forums are full of people complaining about them. IMO both these companies offer great products and customer service.

In other news PSA no longer offers free returns, I guess people were abusing the policy, I mean ordering 7.1 systems and returning them unopened is just insane.