H91 to H92 Horn Swap - The Before

[toddalin]

H91 to H92 Swap

This documents the before in changing out the H91 to an H92 horn in the L200 cabinet. The intent is to boost a dip in the ~600-800 Hz frequency response that, to my ear, has a detrimental effect on the male voice.

Components in the L200 cabinets include a 2205J Alnico woofer recently reconed as a 2235 (<2 years ago) and remaged (<2 years and again ~6 months ago). Woofer was previously tested, and retested ~6 months ago after the remag, using Woofer Tester 2 software. The woofer checks out to the specs of a new 2235. Grumpy performed the testing.

The existing horn is the H91 with the L91 lens. The driver is the LE175. I’ve listened to these, to LE85s and to 2425s, and prefer these as being smoother in the lower end of their frequency range. Zilch has documented this in his testing also.

The highs are handled by 2202s (075s). The crossovers are based on the L200B with a 1.5 mfd/0.5mH added for the tweeter. All caps and chokes are of high quality and all caps have Theta by-pass caps. The high end of the LE175 is rolled off using 2.5 mfd/0.5 mH and a “hole” was intentionally left between the mids and highs to reduce “spitting”. I first used a 1.5 mfd cap to roll off high end of the mids, but I thought that the excessive overlap increased sibilance.) While lowering the mids was effective in reducing this, it does leave a slight dip in the 8-9kHz region that will be fixed when the horns are removed. I’ll probably go back to 1.5 mfd on the mid and try changing the tweeter to 1 mfd, or some value between these two depending on further testing to be performed after the H92 is installed.

This first picture presents about the smoothest response I can get out of it as it is. The microphone was placed 78” away and 32” high. The cabinet is “toed in” from the back wall. The rear, near, inner edge is 9” from the wall while the far outer edge is 20”. Note the dip in the ~630 Hz range. This is what I’ve been wrestling with, and the hope is end up with more horn overlap because the woofer is just not cutting it in this range. This is not an effect of improper phasing and reversing the phase only makes the dip deeper and broader and messes things up elsewhere.

http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/Concrete_Rocks/Existing_Woofer_H91_and_075.jpg

So what is the woofer doing? This next picture shows just the woofer through the crossover. Note that the high-end fall-off way shy of the 800 Hz crossover frequency. Also note the notch in the 630 Hz range that was present in the previous picture.

http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/Concrete_Rocks/Exisitng_Woofer.jpg

Obviously the first suspect is the crossover. After all, it wasn’t made by JBL. So what happens when we connect the amp directly to the woofer in the cabinet without using the crossover? This next picture shows the results. Note that it looks pretty much the same with the same rolled-off high-end and notch.

http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/Concrete_Rocks/Woofer_Without_Crossover.jpg

So, this is not an artifact of the crossover and may be inherent in the woofer/cabinet/room response. I’ve also used these crossovers with the W10GTIs and did not get the sloped response or the dip so assume that it is largely the woofer or woofer/cabinet combination.

In the past, I had noted that putting a resistor in series with the woofer reduced this phenomenon (i.e., brought up the high-end response). Many thought I was crazy (still do) but this next picture clearly shows that the addition of the 8-ohm resistor in series with the woofer extends the high-end response and the general downward slope is lessened. The “hump” to the right of the notch is clearly elevated and is almost up to that on the left of the notch. It's serendipity is that it also extends the low-end response as noted in the picture.

http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/Concrete_Rocks/Woofer8_Without_Crossover_Testing002.jpg

The cost of the resistor is about 5-6 dB of efficiency. Again, this is without any crossover being used.

This picture is similar except that 16 ohms is in series with the woofer. The hump to the right is elevated a little further at the cost of a great deal of efficiency, and the gain in response over the 8 ohm resistor does not warrant the loss of efficiency. Again, in neither picture is the crossover used.

Stay tuned for more.

http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/Concrete_Rocks/L200_Woofer16_Without_Crossover.jpg

[Doc Mark]

Evening, Todd,

Wonderful stuff!! Thanks for sharing, and I'll look forward to seeing the results of your further testing. Well done! Take care, and God Bless!

Every Good Wish,
Doc

[4313B]

In the past, I had noted that putting a resistor in series with the woofer reduced this phenomenon (i.e., brought up the high-end response). Many thought I was crazy (still do)It just isn't done.
The cost of the resistor is about 5-6 dB of efficiency.Yep, you're throwing away perfectly good efficiency.



Do you have an impedance curve of this driver in this box? What does it look like around 630 Hz? What does a test tone around 630 Hz sound like?

[toddalin]

[quote=4313B;227487]It just isn't done.Yep, you're throwing away perfectly good efficiency.

Efficiency is not a problem. The mains are ~11 dB louder than the surrounds so are attenuated by that value anyway. This would just reduce that attenuation to ~5 dB. Actually, the speaker efficiency is only down about 3 dB. The other 2-3 dB loss comes from running the amp at twice the impedience.

Sound is quieter in the noted region.

WT2 results are included. But these are not in the box. Still, if these parameters are on target, others with similar parameters and similar boxes should expect similar results.

;================================================= =================
; Woofer Tester 2 Log File: 2235_remag.log
;------------------------------------------------------------------
Calibration test NOT complete
Calibration drive current 3181.82 uA
;------------------------------------------------------------------
Calibration R = 10.000 ohms
Cable Resistance = 0.000 ohms
Cable Inductance = 0.000 micro-h
KResist = 1.000000 ohms/ohm
(internal R= = 220.000 ohms)
KPhase = 0.000000 microrads/Hz
;================================================= =================
;================================================= =================
Q test completed: Wed Nov 14 19:46:55 2007
Q drive current 3181.82 uA
;------------------------------------------------------------------
Revc= 5.7164 ohms
Fs = 21.3120 Hz
Zmax= 190.1967 ohms
Ro = 32.9732 ohms
F0 = 15.7090 Hz
F1 = 29.8281 Hz
Fmin= 185.8118 Hz
Qms = 8.7068
Qes = 0.2698
Qts = 0.2617
Le = 1.2133 mH @1kHz
XLe = 12.0315 impedance @1kHz
PLe = 39.3193 phase @1kHz
;------------------------------------------------------------------
; Freq-Hz Impedance Phase Real Imag L-mH
0.0 5.7164 +0.0000 5.7164 0.0000 0.0000
1.0 5.8760 +9.7731 5.7908 0.9974 158.7466
2.0 6.1676 +18.0177 5.8652 1.9077 151.8105
10.0 13.7336 +64.9088 5.8239 12.4376 197.9505
10.8 15.3217 +62.0561 7.1799 13.5353 199.6544
11.6 17.0220 +63.6475 7.5559 15.2531 208.5242
12.6 19.7062 +63.9898 8.6418 17.7103 224.3961
13.6 22.2312 +67.2627 8.5925 20.5035 240.7727
14.6 26.4514 +68.3680 9.7512 24.5885 267.6087
15.4 31.0861 +68.9049 11.1884 29.0028 298.9810
15.6 32.8993 +68.8937 11.8470 30.6922 313.3922
15.6 32.8696 +68.8704 11.8488 30.6597 312.3108
15.6 31.3086 +69.6137 10.9063 29.3476 298.5869
15.7 31.5543 +69.7359 10.9287 29.6013 300.8056
15.7 33.1786 +68.6287 12.0906 30.8972 313.9739
15.7 31.3155 +69.6071 10.9121 29.3528 298.2788
15.7 31.6105 +69.6849 10.9746 29.6442 300.8803
15.7 31.7174 +69.9107 10.8944 29.7876 301.9726
15.7 33.3536 +67.5703 12.7261 30.8303 312.5420
15.7 33.6043 +68.3699 12.3870 31.2379 316.4849
15.7 33.1307 +70.7216 10.9384 31.2729 316.6485
15.7 33.6445 +70.9967 10.9554 31.8109 321.7072
15.7 34.0350 +67.5453 12.9998 31.4545 318.0961
15.8 33.5910 +70.9034 10.9897 31.7424 320.1828
16.0 35.7725 +70.2175 12.1072 33.6613 333.8227
16.7 39.0423 +70.6791 12.9175 36.8435 351.5012
17.0 44.0061 +65.5998 18.1793 40.0755 374.6513
17.3 48.3868 +69.4180 17.0103 45.2983 415.7473
18.0 59.2929 +66.3980 23.7397 54.3329 479.7245
18.4 62.0490 +65.1416 26.0840 56.3002 487.8062
18.7 72.5654 +62.8311 33.1345 64.5588 548.3597
19.5 97.4416 +55.9734 54.5262 80.7574 659.8933
19.8 107.4150 +51.7912 66.4393 84.4026 677.7712
20.2 139.2423 +41.0172 105.0601 91.3827 718.3505
20.6 157.2766 +32.3256 132.9023 84.1005 650.6305
21.0 179.5123 +16.2043 172.3808 50.0954 380.1942
21.2 187.4273 +6.5433 186.2064 21.3582 160.5564
21.3 189.4233 +1.4969 189.3586 4.9484 37.0208
21.3 189.1825 +2.0493 189.0615 6.7652 50.6122
21.3 190.1097 +0.3672 190.1058 1.2185 9.1051
21.3 190.1967 -0.4664 190.1904 -1.5484 -11.5631
21.3 189.9431 -0.9434 189.9174 -3.1274 -23.3411
21.3 189.6425 -0.5006 189.6353 -1.6570 -12.3668
21.4 189.5815 -2.8061 189.3542 -9.2810 -69.1014
21.4 189.0875 -2.2357 188.9436 -7.3762 -54.9180
21.4 187.9723 -1.3715 187.9184 -4.4990 -33.4837
22.4 151.4145 -37.6404 119.8990 -92.4694 -657.6654
24.1 83.6709 -60.9949 40.5710 -73.1766 -482.3573
26.1 56.0276 -68.2604 20.7520 -52.0427 -317.9408
28.1 38.7958 -74.3856 10.4423 -37.3640 -211.5582
29.2 34.1882 -67.5412 13.0605 -31.5952 -172.3476
29.7 33.2074 -71.4086 10.5871 -31.4745 -168.4449
29.7 33.1868 -70.4950 11.0807 -31.2823 -167.4150
29.7 33.1161 -71.4003 10.5625 -31.3865 -167.9573
29.8 33.0935 -70.7386 10.9168 -31.2410 -166.9944
29.8 32.9983 -70.9890 10.7492 -31.1985 -166.5667
29.8 32.8982 -72.1271 10.0967 -31.3105 -167.1648
29.8 32.8839 -70.9883 10.7123 -31.0902 -165.8888
29.8 32.9322 -71.2667 10.5767 -31.1876 -166.4086
29.8 32.8005 -71.5951 10.3561 -31.1228 -165.9628
29.9 32.6680 -71.5851 10.3197 -30.9952 -165.0838
30.0 32.1351 -71.2116 10.3499 -30.4227 -161.2540
30.3 31.4288 -70.7833 10.3446 -29.6776 -155.7964
30.3 31.1434 -71.0093 10.1345 -29.4483 -154.5345
32.2 26.4107 -70.4682 8.8299 -24.8909 -123.0904
34.7 20.9946 -68.7988 7.5926 -19.5737 -89.7109
37.5 18.6402 -67.1942 7.2251 -17.1829 -72.9895
40.4 16.6187 -63.2869 7.4705 -14.8450 -58.4430
43.6 14.5715 -62.4016 6.7506 -12.9135 -47.1180
47.1 12.9962 -59.7831 6.5407 -11.2304 -37.9774
50.8 11.8126 -55.4793 6.6942 -9.7326 -30.5037
54.8 10.8582 -53.9829 6.3849 -8.7826 -25.5113
59.1 10.0622 -50.4659 6.4049 -7.7604 -20.8922
63.8 9.3023 -46.6520 6.3854 -6.7646 -16.8785
68.8 8.7331 -43.8829 6.2944 -6.0536 -13.9990
74.3 8.2710 -39.9321 6.3423 -5.3090 -11.3785
80.1 7.8762 -36.6121 6.3222 -4.6973 -9.3307
86.5 7.5401 -32.8588 6.3338 -4.0911 -7.5316
93.3 7.3011 -29.2337 6.3712 -3.5656 -6.0838
100.6 7.0980 -25.8045 6.3903 -3.0898 -4.8860
108.6 6.9790 -22.1009 6.4662 -2.6258 -3.8484
117.2 6.8290 -19.2135 6.4486 -2.2474 -3.0527
126.4 6.7245 -15.7058 6.4734 -1.8203 -2.2916
136.4 6.6536 -12.6186 6.4928 -1.4535 -1.6960
147.2 6.6056 -9.2859 6.5191 -1.0659 -1.1526
158.8 6.6031 -6.1927 6.5645 -0.7123 -0.7139
171.3 6.6280 -3.0710 6.6185 -0.3551 -0.3298
184.6 6.6613 -0.2157 6.6612 -0.0251 -0.0216
184.6 6.6616 -0.2185 6.6615 -0.0254 -0.0219
184.9 6.6620 -0.1499 6.6620 -0.0174 -0.0150
185.0 6.6649 -0.1326 6.6649 -0.0154 -0.0133
185.3 6.6655 -0.0674 6.6655 -0.0078 -0.0067
185.5 6.6599 -0.2751 6.6598 -0.0320 -0.0274
185.5 6.6703 +0.0241 6.6703 0.0028 0.0024
185.5 6.6751 -0.2160 6.6750 -0.0252 -0.0216
185.7 6.6678 -0.0077 6.6678 -0.0009 -0.0008
185.8 6.6669 +0.0170 6.6669 0.0020 0.0017
185.8 6.6704 +0.0650 6.6704 0.0076 0.0065
185.9 6.6680 +0.0394 6.6680 0.0046 0.0039
185.9 6.6710 +0.1921 6.6709 0.0224 0.0191
186.4 6.6551 +0.1043 6.6551 0.0121 0.0103
186.4 6.6662 +0.1419 6.6661 0.0165 0.0141
188.2 6.6803 +0.5611 6.6800 0.0654 0.0553
191.9 6.6877 +1.2850 6.6860 0.1500 0.1244
199.5 6.7496 +2.5843 6.7428 0.3043 0.2428
200.5 6.7484 +2.7901 6.7404 0.3285 0.2608
216.3 6.8346 +5.6847 6.8010 0.6770 0.4981
233.4 6.9608 +8.4431 6.8853 1.0220 0.6969
251.8 7.0730 +10.6208 6.9518 1.3036 0.8239
271.7 7.2471 +12.9494 7.0628 1.6240 0.9512
293.2 7.4034 +14.6773 7.1618 1.8758 1.0183
316.3 7.5391 +16.5277 7.2276 2.1447 1.0791
341.3 7.6909 +18.5418 7.2917 2.4457 1.1404
368.3 7.8374 +20.7255 7.3302 2.7736 1.1987
397.4 8.0536 +23.0357 7.4114 3.1514 1.2623
428.7 8.2927 +25.2700 7.4991 3.5400 1.3141
462.6 8.5949 +26.9939 7.6585 3.9012 1.3422
499.1 8.9460 +28.8300 7.8372 4.3139 1.3756
538.5 9.2732 +30.2295 8.0122 4.6687 1.3797
581.1 9.6292 +31.4595 8.2138 5.0254 1.3765
627.0 9.9805 +32.3916 8.4276 5.3466 1.3572
676.5 10.2727 +33.3635 8.5797 5.6495 1.3292
729.9 10.5817 +34.8143 8.6876 6.0413 1.3173
787.5 11.0384 +36.3420 8.8914 6.5414 1.3220
849.7 11.6421 +37.4641 9.2408 7.0815 1.3264
916.8 11.8635 +35.6571 9.6394 6.9156 1.2005
989.2 11.9434 +38.9222 9.2920 7.5036 1.2072
1000.0 12.0315 +39.3193 9.3079 7.6237 1.2133
1067.4 12.5485 +41.2701 9.4316 8.2771 1.2342
1151.7 13.2790 +42.8365 9.7374 9.0285 1.2477
1242.6 14.2059 +43.9105 10.2342 9.8522 1.2619
1340.7 14.4107 +39.2113 11.1657 9.1102 1.0814
1446.6 14.7163 +44.2453 10.5422 10.2680 1.1297
1560.9 15.5674 +45.5008 10.9112 11.1036 1.1322
1684.1 16.2922 +45.6022 11.3986 11.6408 1.1001
1817.1 16.8680 +47.1264 11.4767 12.3619 1.0827
1960.6 17.7363 +48.3286 11.7921 13.2485 1.0755
2115.5 18.5616 +48.9572 12.1880 13.9995 1.0532
2282.5 19.4899 +49.7138 12.6023 14.8673 1.0367
2462.8 20.4178 +50.5285 12.9795 15.7613 1.0186
2657.3 21.4548 +51.1805 13.4493 16.7159 1.0012
2867.1 22.5369 +51.7919 13.9395 17.7088 0.9830
3093.5 23.6754 +52.3479 14.4625 18.7447 0.9644
3337.8 24.8744 +52.8482 15.0224 19.8259 0.9453
3601.4 26.1395 +53.3173 15.6153 20.9627 0.9264
3885.8 27.4611 +53.7164 16.2510 22.1363 0.9067
4192.7 28.8585 +54.1613 16.8968 23.3947 0.8881
4523.8 30.3444 +54.5339 17.6065 24.7143 0.8695
4881.1 31.9151 +54.8697 18.3652 26.1016 0.8511
5266.6 33.5940 +55.1539 19.1947 27.5702 0.8332
5682.5 35.2588 +55.4025 20.0202 29.0236 0.8129
6131.2 37.1233 +55.7228 20.9078 30.6758 0.7963
6615.4 39.1273 +55.8618 21.9579 32.3851 0.7791
7137.9 41.3115 +55.9638 23.1227 34.2342 0.7633
7701.6 43.5498 +55.7423 24.5148 35.9945 0.7438
8309.8 45.0181 +55.4321 25.5425 37.0703 0.7100
8966.0 47.0988 +56.2592 26.1604 39.1655 0.6952
9674.1 49.5865 +56.5449 27.3362 41.3709 0.6806
10438.1 52.1516 +56.7866 28.5665 43.6319 0.6653
11262.4 54.8178 +57.0296 29.8322 45.9895 0.6499
12151.8 57.6870 +57.1937 31.2549 48.4864 0.6350
13111.5 60.6623 +57.2618 32.8062 51.0261 0.6194
14146.9 63.7429 +57.3489 34.3907 53.6698 0.6038
15264.1 66.9559 +57.5237 35.9521 56.4849 0.5890
16469.6 70.4289 +57.6695 37.6655 59.5108 0.5751
17770.2 74.0491 +57.7895 39.4705 62.6526 0.5611
19173.5 77.8858 +57.9025 41.3856 65.9806 0.5477
20000.0 80.0932 +57.6739 42.8288 67.6803 0.5386
;================================================= =================
;================================================= =================
Vas test completed: Wed Nov 14 19:58:19 2007
Vas drive current 3181.82 uA
;------------------------------------------------------------------
Revc = 5.7164 ohms
Fs = 21.3120 Hz
Zmax = 190.1967 ohms
Qes = 0.2698
Qms = 8.7068
Qts = 0.2617
Le = 1.2133 mH (at 1 kHz)
Diam = 342.9000 mm ( 13.5000 in )
ConeArea =92347.4431 mm^2(143.1388 in^2)
Vas = 342.1111 L ( 12.0815 ft^3)
BL = 23.5367 N/A
Mms = 195.2519 g
Cms = 285.6256 uM/N
Kms = 3501.0862 N/M
Rms = 3.0029 R mechanical
Efficiency = 1.1833 %
Sensitivity= 92.7309 dB @1W/1m
Sensitivity= 94.1906 dB @2.83Vrms/1m
;------------------------------------------------------------------
; When testing drivers with an up/down radiation (cone motion)
; enough weight should be used to get a decent resonance change
; without significantly altering the drivers suspension zero point.
; A typically good configuration is when Fs/Fsa=1.25.
; Horizontally mounted drivers are less susceptable but require
; a clay or soft caulk mass. The following may be of help
;------------------------------------------------------------------
Fs= 21.3120 Mms =195.2519 g
Fsa= 17.6322 Mms+Ma=285.2519 g
Fs/Fsa = 1.2087
Ideal Test Mass =109.8292 g
Test Mass used = 90.0000 g
Missed ideal by =-19.8292 g (too light)
Nickels used = 18.0000
Nickels desired = 21.9658
;------------------------------------------------------------------
; Freq-Hz Impedance Phase Real Imag L-mH
1.0 5.7164 +0.0000 5.7164 0.0000 0.0000
10.0 14.8898 +56.3115 8.2590 12.3893 197.1813
10.8 16.9387 +62.8746 7.7230 15.0757 222.3750
11.6 19.4244 +65.5701 8.0336 17.6853 241.7758
12.6 24.2571 +67.8802 9.1339 22.4718 284.7257
13.6 29.5157 +67.9458 11.0827 27.3560 321.2418
14.6 40.0425 +66.5911 15.9085 36.7467 399.9324
15.8 61.1994 +63.5191 27.2888 54.7785 552.5460
17.0 124.8791 +35.7364 101.3659 72.9366 682.8425
17.0 134.4037 +35.8246 108.9762 78.6673 735.4317
17.3 155.5187 +20.1573 145.9931 53.5916 492.2028
17.5 163.4534 +9.0874 161.4018 25.8161 234.8518
17.6 165.8403 +3.9407 165.4482 11.3973 103.1857
17.6 166.9092 +0.8412 166.8912 2.4506 22.1329
17.6 167.6515 -0.9646 167.6277 -2.8223 -25.4755
17.6 167.2485 -0.1218 167.2481 -0.3555 -3.2066
17.7 166.8143 -1.4120 166.7636 -4.1106 -37.0373
17.7 167.3574 -0.8329 167.3397 -2.4328 -21.9194
17.7 166.5544 -0.3745 166.5509 -1.0886 -9.8041
18.4 135.6515 -35.9134 109.8648 -79.5679 -689.4069
;================================================= =================
;================================================= =================
Vented box test NOT complete
Vented box drive current 0.00 uA
;------------------------------------------------------------------
Revc = 5.7164
flo = 0.0000, Zlo = 0.0000
fhi = 0.0000, Zhi = 0.0000
fm = 0.0000, Zmid = 0.0000
Fsb = 0.0000
ha = 0.0000
alpha= 1.0000
Qloss= 0.0000
;================================================= =================
;================================================= =================
Arbitrary 1 Sweep test completed: Fri Sep 28 15:28:51 2007
Arbitrary 1 Sweep drive current 3181.82 uA
;------------------------------------------------------------------
; Freq-Hz Impedance Phase Real Imag L-mH
10.0 14.8973 +57.0718 8.0980 12.5041 199.0087
10.8 20.5422 +54.6820 11.8757 16.7615 247.2427
11.6 28.0626 +54.4530 16.3147 22.8328 312.1465
12.6 46.1639 +48.0097 30.8839 34.3117 434.7417
13.6 81.9426 +6.1235 81.4751 8.7410 102.6455
14.6 55.9218 -44.9904 39.5493 -39.5361 -430.2910
15.8 33.4776 -59.4980 16.9922 -28.8447 -290.9537
17.0 20.8554 -59.3683 10.6262 -17.9452 -167.7632
18.4 16.5091 -58.7505 8.5644 -14.1139 -122.2885
19.8 13.2059 -53.8959 7.7816 -10.6697 -85.6797
21.4 10.9251 -48.6142 7.2228 -8.1968 -61.0044
23.1 9.5902 -40.4076 7.3024 -6.2165 -42.8801
24.9 8.7464 -34.8361 7.1789 -4.9962 -31.9401
26.9 8.1729 -28.1970 7.2030 -3.8617 -22.8807
29.0 7.5914 -19.6245 7.1504 -2.5496 -14.0006
31.3 7.6181 -13.3026 7.4137 -1.7529 -8.9211
33.7 7.7010 -5.2423 7.6688 -0.7036 -3.3189
36.4 8.1064 +3.1904 8.0939 0.4512 1.9723
39.3 9.0843 +12.8585 8.8565 2.0217 8.1911
42.4 11.3866 +21.2707 10.6109 4.1308 15.5115
45.7 18.1688 +26.5694 16.2500 8.1266 28.2827
49.3 31.1706 -13.6248 30.2935 -7.3427 -23.6841
53.2 20.8709 -52.6237 12.6696 -16.5854 -49.5814
57.4 12.3043 -56.6765 6.7596 -10.2813 -28.4859
62.0 9.2068 -49.3030 6.0034 -6.9803 -17.9245
66.9 8.0213 -40.8672 6.0660 -5.2484 -12.4908
72.2 7.3353 -33.9658 6.0837 -4.0982 -9.0395
77.9 7.2099 -28.7358 6.3219 -3.4663 -7.0861
84.0 6.8722 -25.0194 6.2274 -2.9064 -5.5067
90.6 6.6667 -20.8425 6.2305 -2.3720 -4.1653
97.8 6.6515 -17.9984 6.3261 -2.0553 -3.3449
105.5 6.5385 -13.7088 6.3522 -1.5495 -2.3372
113.8 6.5911 -11.4342 6.4603 -1.3066 -1.8266
122.8 6.6247 -8.3092 6.5552 -0.9574 -1.2404
132.5 6.6852 -6.0617 6.6478 -0.7060 -0.8477
143.0 6.7932 -4.0382 6.7763 -0.4784 -0.5324
154.3 6.8940 -2.2216 6.8888 -0.2672 -0.2756
166.5 7.1230 -1.0199 7.1219 -0.1268 -0.1212
179.6 7.0664 -1.2987 7.0646 -0.1602 -0.1419
193.8 7.0544 -0.0402 7.0544 -0.0050 -0.0041
209.1 7.1505 +1.9721 7.1462 0.2461 0.1873
225.6 7.3223 +3.5359 7.3084 0.4516 0.3185
243.5 7.4766 +4.2644 7.4559 0.5560 0.3634
262.7 7.6094 +5.0187 7.5802 0.6657 0.4033
283.4 7.7141 +5.4537 7.6792 0.7332 0.4117
305.8 7.8460 +6.1192 7.8013 0.8364 0.4353
330.0 7.9517 +6.6025 7.8990 0.9143 0.4410
356.0 8.0932 +7.3912 8.0260 1.0411 0.4654
384.1 8.2474 +8.0127 8.1668 1.1496 0.4763
414.5 8.4280 +8.6173 8.3328 1.2628 0.4849
447.2 8.6372 +9.4008 8.5212 1.4108 0.5021
482.5 8.9547 +10.6639 8.8000 1.6570 0.5465
520.6 9.4797 +10.9696 9.3065 1.8039 0.5514
561.8 10.1096 +10.3213 9.9460 1.8113 0.5132
606.1 10.8850 +8.4275 10.7675 1.5953 0.4189
654.0 11.7012 +4.2698 11.6687 0.8712 0.2120
705.6 12.2054 -2.3929 12.1948 -0.5096 -0.1149
761.4 11.8778 -10.4908 11.6793 -2.1627 -0.4521
821.5 10.6531 -16.3609 10.2217 -3.0008 -0.5814
886.4 9.3629 -17.5369 8.9277 -2.8212 -0.5066
956.4 8.4469 -15.1433 8.1536 -2.2066 -0.3672
1031.9 7.9963 -10.5836 7.8603 -1.4687 -0.2265
1113.4 8.0283 -6.1586 7.9820 -0.8613 -0.1231
1201.3 8.4190 -3.5687 8.4027 -0.5240 -0.0694
1296.2 8.8705 -3.6293 8.8527 -0.5615 -0.0689
1398.5 9.1772 -5.2425 9.1388 -0.8385 -0.0954
1509.0 9.3518 -6.6905 9.2881 -1.0895 -0.1149
1628.1 9.5242 -9.4124 9.3960 -1.5576 -0.1523
1756.7 9.4106 -12.6932 9.1806 -2.0678 -0.1873
1895.4 9.0944 -14.9560 8.7863 -2.3471 -0.1971
2045.1 8.8231 -16.4545 8.4617 -2.4992 -0.1945
2206.6 8.4788 -18.1922 8.0550 -2.6471 -0.1909
2380.9 8.0835 -18.6472 7.6591 -2.5846 -0.1728
2568.9 7.7693 -18.7909 7.3552 -2.5026 -0.1550
2771.8 7.4986 -18.2979 7.1195 -2.3542 -0.1352
2990.7 7.2756 -18.0375 6.9180 -2.2528 -0.1199
3226.9 7.0623 -17.4169 6.7385 -2.1139 -0.1043
3481.7 6.8956 -16.4708 6.6126 -1.9551 -0.0894
3756.7 6.7818 -15.6613 6.5300 -1.8308 -0.0776
4053.4 6.6899 -14.8852 6.4654 -1.7185 -0.0675
4373.5 6.6173 -14.3449 6.4110 -1.6395 -0.0597
4718.8 6.5570 -13.8663 6.3659 -1.5714 -0.0530
5091.5 6.4961 -13.5034 6.3165 -1.5168 -0.0474
5493.6 6.4376 -13.2693 6.2657 -1.4776 -0.0428
5927.4 6.3778 -13.1210 6.2113 -1.4478 -0.0389
6395.5 6.3119 -13.0286 6.1494 -1.4229 -0.0354
6900.6 6.2365 -12.9631 6.0776 -1.3990 -0.0323
7445.6 6.1568 -12.8894 6.0017 -1.3734 -0.0294
8033.5 6.0659 -12.7780 5.9157 -1.3416 -0.0266
8668.0 5.9708 -12.5714 5.8276 -1.2996 -0.0239
9352.5 5.8802 -12.2511 5.7463 -1.2478 -0.0212
10091.1 5.8029 -11.9370 5.6774 -1.2002 -0.0189
10888.0 5.7106 -11.6279 5.5934 -1.1510 -0.0168
11747.9 5.6195 -11.1740 5.5129 -1.0890 -0.0148
12675.6 5.5324 -10.6151 5.4377 -1.0191 -0.0128
13676.6 5.4532 -9.9652 5.3709 -0.9437 -0.0110
14756.7 5.3811 -9.2159 5.3116 -0.8618 -0.0093
15922.1 5.3244 -8.2953 5.2687 -0.7682 -0.0077
17179.5 5.2849 -7.8531 5.2353 -0.7221 -0.0067
18536.2 5.2364 -7.0627 5.1967 -0.6438 -0.0055
20000.0 5.1856 -6.2707 5.1546 -0.5664 -0.0045

[4313B]

Well hell. I'm reconing five 2235H's now so I guess I will mount them in a box and sweep them just for grins.

[toddalin]

Well hell. I'm reconing five 2235H's now so I guess I will mount them in a box and sweep them just for grins.

Thanks. Are any in Alnico baskets? Lets us know what you find.

[grumpy]

IIRC, the first WT2 sweep listed was an out-of-box experience...
the last one shown was system (in-box + all crossovers & drivers).
(at least that's how they appear when plotted)

[Guido]

Thanks. Are any in Alnico baskets? Lets us know what you find.

I frequently remag and recone 15" Alnico baskets to 2235.
I usually end up with BL around 23 NA. Seems that these Alnicos can be a bit "overcharged".

Before remag I often measure as low as 12 - 15 NA though.

[4313B]

Seems that these Alnicos can be a bit "overcharged".Evidently so. There are stories of Greg changing the Q at will by dumping a bunch of juice into those old motors.

The 1500AL is AlNiCo done right. :yes:

[Beowulf57]

Toddalin: you note that you might be getting a room response effect. Have you tried moving your mike position around? Does this dip also show up in a nearfield response measurement? If not, you could try raising/repositioning the cabinets. Using the room dimensions, there are simple calculations that can tell you where the frequency cancellation nodes will occur. Or perhaps you've already gone down that road?

[4313B]

I was under the impression that he had already done that but I could be wrong.

[toddalin]

Toddalin: you note that you might be getting a room response effect. Have you tried moving your mike position around? Does this dip also show up in a nearfield response measurement? If not, you could try raising/repositioning the cabinets. Using the room dimensions, there are simple calculations that can tell you where the frequency cancellation nodes will occur. Or perhaps you've already gone down that road?

I've tried various positions of the speakers and mic, and while there is some variation, I still get the same general response pattern. I don't get this response using the W10GTIs placed directly on top of the L200s, so if it is the room... :dont-know

[pos]

If you place a woofer on top of the L200 they are much further away from the floor, so you don't get the same peaks and dips caused by these reflections on the floor.

[toddalin]

If you place a woofer on top of the L200 they are much further away from the floor, so you don't get the same peaks and dips caused by these reflections on the floor.

Agreed.

But, if this is a case of the woofer placement with respect to the floor/room:

"Floor bounce" attenuation is typically at a far lower frequency (typically 150-300 Hz) and this attenuation also shows on the graphic.

Except that I've raised the base of the L200s by 1-1/2", this same (or similar) "floor bounce" attenuation should be prevelent for all similar cabinet/speaker installations and there are many on this forum using similar equipment. Are they experiencing this same phenomon without realizing it?

I also get it on my center channel and this cabinet is different than the L200 cabinet with a different component arrangement and in a different room position.

[pos]

You always get dips and peaks from the floor (and walls and celling as well). The further the speaker from the boundaries, the lower in frequency these problems will occure.
Try to put some pillows on the floor between the speaker and your mic. If the dip reduces then you can be sure the floor is responsible. If it doesn't then you could also try the same with the other walls, in turn (rear wall, side walls, celling...)

[grumpy]

IIRC, many or most of these suggestions were tried, without an obvious conclusion
(did -not- try a tone at 630Hz).

I believe it was left for further investigation, when time permitted, possibly including an
outdoor test.