Originally Posted by bscool
If that is the case then it isn't really a long term output compression reading is it?
According to this article in section 3 http://www.audioholics.com/loudspeak...ubwoofer-tests
"the sweep is repeated in rapid succession, each time with the level increased by 5dB, until the subwoofer ceases to increase in output or is driven into limiting, over-excursion, distortion or other obvious duress"
So was the test stopped early and could have gotten higher or did hit its limit like according to the article is what the highest reading is showing? Just curious why the 15's are higher than the 18 according to my understanding of the test and interpreting the results but then the 18s are higher if you look at the CEA-2010 RATINGS on the same product page.
I am not trying to nit picky or find flaws with PSA(I like their subs) I am just interested to understand how that works or if it is a mistake. Because I would imagine most people buy the s3600 hoping for higher output. Or is it just after running the compression sweep and the voice coils heat up the 15s stay cooler or more efficient? Hence they show higher output in the compression sweeps?
Also reading more the CEA-2010 RATINGS are also done using sweeps,
section 3 http://www.audioholics.com/loudspeak...asurement-data
"Distortion isn't measured during these sweep tests but levels are increased for each progressive sweep until compression is observed or mechanical or audible distortion is heard. If mechanical noise or distortion is heard, the sweep is redone at a reduced level until the output sounds clean. That level is then recorded as the maximum sustained sweep level for the product."
And just below that it talks about amplifier output vs driver output limited and how they will shower lower results in an amplifier limited sub. It is getting too late so I'll have to look at it tomorrow and maybe Tom will have chimed in to explain it better. He is always good about making things easier to understand.
To best of my knowledge CEA-2010 testing uses tone bursts, not sweep.
WRT your question I understand your point, but IMHO it may also be that some test is sensitive enough to show an output difference (CEA 2010), and some not (sweep) in this particular comparison. To me the next question is not just whether S3000 does indeed have equal or better outputs at some frequencies, but also maybe the test itself is not sensitive with this particular measurement. BTW, where it really counts, the low frequency, S3000 & S3600 are the same: both curves hit 106 dB at 20 hz.
A series of 6.5-cycle tone bursts centered at 63, 50, 40, 31.5, 25 and 20 Hz is played through the subwoofer. These tone bursts (waveform shown below) are intended to simulate the signals that a subwoofer would receive when playing typical music or movies. They are also short enough in duration that they are unlikely to damage a subwoofer due to thermal overload (i.e., burning out the voice coil or the amplifier output transistors) You can find these tones in 256 kbps MP3 form on the Tech page of this website. Here’s the waveform of the 63 Hz tone burst. Note that the peak level of the tone burst is about -1 dBFS.
The technician raises the playback level for the tone bursts until the distortion exceeds any of the thresholds set by CEA-2010. For example, the threshold for the 2nd harmonic (126 Hz for a 63 Hz tone burst) is -10 dB below the peak level of the fundamental tone. So if the peak level of the fundamental is 120 dB SPL, the level of the 2nd harmonic cannot exceed 110 dB SPL. Here’s the complete list of CEA-2010 distortion thresholds:
2nd harmonic: -10 dB
3rd harmonic: -15 dB
4th and 5th harmonics: -20 dB
6th, 7th, 8th harmonics: -30 dB
9th and higher harmonics: -40 dB