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Discussion Starter #1 (Edited)
Chase VS 18.1​

Read the full review here

Before we start I would like to say that the tests that I did back in February on the Chase VS-18.1 were performed before any methodology was written for The Sub Zone and as a result the measurements for max output were based on maintaining <10% THD. This is different than other tests that have been performed on this beast utilizing the CEA 2010 standard.

Testing Gear:
  • Dell E6400
  • IBF-Akustik EMM-8
  • IBF-Akustik MP-1r
  • IBF-Akustik SC-1
  • REW
The measurements were taken from a single sub sitting on a concrete surface in the middle of a parking lot with the nearest structure being well over 100 feet away. I ran the Dayton power off of an APC 3000 SmartUPS plugged into the 110 outlet in my truck. The EMM-8 was placed two meters from the sub, as you can see below.

Setup Images


Frequency Response


Group Delay


Waterfall


RT60


Spectrograph


Max Output at 10% THD Threshold
I took measurements at 20Hz, 25Hz, 32Hz, 40Hz, 50Hz, 63Hz, and 80Hz. I took these measurements at a distance of two meters and pushed the volume until the sub hit 10% THD. I will be posting some more measurements at 1 meter in about two weeks when I take measurements for several subs and posting in the subwoofer forum.

















Click the Spoiler button for the REW notes from each individual frequency

Spoiler
20 Hz
65536-point spectrum using Rectangular window and no averaging
Input RMS 104.8 dB
Distortion at 20.1 Hz, -16.8 dB FS based on 8 harmonics:
THD 10.3978 %
THD+N 17.8690 %
2nd harmonic 6.1275%
3rd harmonic 4.9729%
4th harmonic 1.5518%
5th harmonic 5.0335%
6th harmonic 0.7714%
7th harmonic 3.3197%
8th harmonic 0.5737%
9th harmonic 2.4797%

25 Hz
65536-point spectrum using Rectangular window and no averaging
Input RMS 109.2 dB
Distortion at 24.9 Hz, -12.4 dB FS based on 8 harmonics:
THD 10.3469 %
THD+N 13.5767 %
2nd harmonic 6.2372%
3rd harmonic 7.9082%
4th harmonic 0.7784%
5th harmonic 1.1143%
6th harmonic 1.0262%
7th harmonic 1.3103%
8th harmonic 0.7049%
9th harmonic 0.7073%

32 Hz
65536-point spectrum using Rectangular window and no averaging
Input RMS 111.9 dB
Distortion at 32.0 Hz, -9.7 dB FS based on 8 harmonics:
THD 10.1465 %
THD+N 17.7388 %
2nd harmonic 4.9034%
3rd harmonic 8.7128%
4th harmonic 1.2614%
5th harmonic 1.0977%
6th harmonic 0.1425%
7th harmonic 0.2564%
8th harmonic 0.2232%
9th harmonic 0.2525%


40 Hz
65536-point spectrum using Rectangular window and no averaging
Input RMS 116.8 dB
Distortion at 39.9 Hz, -4.8 dB FS based on 8 harmonics:
THD 9.8350 %
THD+N 14.6519 %
2nd harmonic 6.7166%
3rd harmonic 5.7050%
4th harmonic 2.5732%
5th harmonic 1.8927%
6th harmonic 1.3640%
7th harmonic 1.9382%
8th harmonic 1.1534%
9th harmonic 1.3842%

50 Hz
65536-point spectrum using Rectangular window and no averaging
Input RMS 115.4 dB
Distortion at 50.0 Hz, -6.5 dB FS based on 8 harmonics:
THD 10.0908 %
THD+N 28.0294 %
2nd harmonic 5.7472%
3rd harmonic 6.8447%
4th harmonic 2.1389%
5th harmonic 3.2743%
6th harmonic 0.3300%
7th harmonic 1.8531%
8th harmonic 0.8813%
9th harmonic 1.5259%

63 Hz
65536-point spectrum using Rectangular window and no averaging
Input RMS 115.8 dB
Distortion at 63.1 Hz, -5.7 dB FS based on 8 harmonics:
THD 10.2653 %
THD+N 13.8368 %
2nd harmonic 9.6407%
3rd harmonic 3.1247%
4th harmonic 1.4080%
5th harmonic 0.6767%
6th harmonic 0.2789%
7th harmonic 0.3129%
8th harmonic 0.1646%
9th harmonic 0.1660%


80 Hz
65536-point spectrum using Rectangular window and no averaging
Input RMS 116.7 dB
Distortion at 80.1 Hz, -4.9 dB FS based on 8 harmonics:
THD 10.0677 %
THD+N 11.0830 %
2nd harmonic 6.0271%
3rd harmonic 6.7835%
4th harmonic 0.6705%
5th harmonic 3.9176%
6th harmonic 1.0061%
7th harmonic 1.3547%
8th harmonic 0.1667%
9th harmonic 0.5871%
 

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20hz, 105db @ 2 meters outside is pretty impressive. Not surprised though, I remember spending a lot of time with that sub. Saying it gets loud is an understatement.
 

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Discussion Starter #3
Hey Ethan, I definitely miss those things for sure! I am going to update the graphs to be more consistent with the other tests in the forum. The actual max output of the Chase is a little higher than I posted as I kept that one under 10% THD so keep that in mind as well. I think the Max Ricci and Craig has test is about another 10-15 db higher using the CEA 2010 method.
 

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What's the difference in the testing methodology? I kinda remember Craig saying something about the new CEA standard is a test tone only lasting like a fraction of a second? Did I remember that correctly?
 

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Discussion Starter #5
It's really focused on measurements taken at 20, 25, 31.5, 40, 50 and 63Hz in order to determine max SPL output. It requires a special mic and Igor OS in order to capture the data.
 

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Oh wow sounds like I need to do some more reading. How much I get done depends on how much longer my electricity stays on. The eye of the hurricane will be about 45 minutes south of here in a few hours :gulp:
 

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Discussion Starter #9
Unfortunately I did not do the compression testing on the Chase. I was really just starting on the testing at that point and had not fully developed the methodology.
 
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