Well, lots of people are looking, but none posting. :banghead:
With a little more sleuthing, I found the following:
L100 (early) = 2" d x 1" l (thickness of panel)
L100A (late) - 3"d x ~8" ("L"...
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Well, lots of people are looking, but none posting. :banghead:
With a little more sleuthing, I found the following:
L100 (early) = 2" d x 1" l (thickness of panel)
L100A (late) - 3"d x ~8" ("L"...
I have searched the forum, but cannot find any specific info on the tuning freq (or vents used) on the various 4310/4311/L100 models.
These all had an interior cabinet of ~1.75 cf (if my math is...
OK, this may be something only I am interested in, but here are my thoughts on a DIY L220. I have a pair of LE14A's. I just got 4 10" PR. Now two 10" PR are just about equal to one 15", so I am...
For those more interested in the sound than the looks, here are my final plots. Note that these are taken with the mike placed right at the cneter of the curved front touching the front. There is...
OK, so it has been a long time, but the speaker is finally together and in the den. Yes, an HD TV on the wall will be an improvement as will finishing the grill covers, but I thought you might like...
Yes, I suspected that was the problem with the H91 - the mouth is too small to support 500 Hz. One of the nice things about a tractrix horn is that it has a defined mouth that cannot be exceeded...
Finally had time to do impedance plots on my LE85 driving both the tractrix and H91 horns. I discovered that my Freq. generator falls off in output at high freq. so this time I recalibrated for...
Looks like Robh might be right. Here is a recap of boost with just a cap
green=0
blue = 0.4uF
Aqua=0.5
Orange = 0.68
Yellow = 1.0
Magenta = 1.5
20653
Per Zilch's suggestion, here are the...
OK, I have some interesting results. First the calculations:
Based upon a 10dB hump, I calculated R= 3.5
With F0=8750, F3h=15000, F3l=6300, I got L=0.05, C=5.37. I had a 0.06mH coil so used that...
To answer Zilch's questions about polar response, I took measurements @ 0, 10, 20, 30, 45 degrees off axis. (The actual degrees may be a bit off, I was using a plastic protractor held on the horn's...
OK, I finally had a chance to do some SPL plots. As follows:
1. No HF bypass (green)
2. 1.0 uF only (no L, no R) (magenta)
3. 0.68 uF (yellow)
4. 0.33 uF (orange)
20642
Now with the smaller...
Do I correctly interpret this to mean that the SPL response we are seeing is what was considered "desirable" for a "Rock & Roll" speaker? "The JBL sound" with "forward" MF? Hmmmmm
So if I understand it correctly, the best we could hope for from this circuit is something on the order of 4dB from 12k-20k (assuming I keep increasing C6 until there is no "boost" @ 12k). If OTOH, I...
I had a break at work and was working on the calculations for the LCR, but I have a question: How do I calculate the value for R? I realize that the easy thing to do is use the 16 ohm side of an...
Thanks, Zilch. Although I haven't gotten to trying to duplicate your impedence measurements yet (Work getting in the way again!), I am glad to see that you have essentially duplicated my results, so...
Sorry for the confusion. The bottom curve is with NO HF BYPASS (i.e. NC= not connected). I then did three curves with the HF BYPASS consisting of a 16 ohm section of L-pad followed by just a 1.0 uF...
Original as far as I know. red wax seals intact.
DCR = 6.9 on each
It will probably be a couple of days before I can get the impedence maeaurements, but I did some more SPL measurements.
I am using the entire network as published by Zilch earlier "as built" with...
Interesting. As Bruce suggests, the tractrix seems to have far less variation than the exponential horn in terms of peaks and valleys. (of course I only started @ 500 so did not include the...
I didn't state, but the L-pad (MF) is set at mid position, the circuit has both the fixed 2.5/5 L-pad and the following 8 resistors. The HF bypass had the 16ohm Lp2 but I set it at a measured 5 ohms...
OK, I'm doing SOMETHING wrong here. Based upon formulae earlier in this thread
http://www.audioheritage.org/vbulletin/showpost.php?p=126752&postcount=4
I derived the following:
Lowest freq for...
I am certainly not the best one to explain a tractix horn, but I will give it a try. A tractrix horn is neither exponential nor constant directivity. It would be closest to a catenoid. Tractrix is...
OK, well the H91 does have better response above 10k
20359
Here is the Tractrix taken at the exact same settings
20361
Here is full range comparison
20360
While it is lacking over 10k, I like...
Yes, my typo. Here are the results of my HF boost with L3=0.06 which is as close as I can come until I get a new order in. As you can see, just about 3 dB variation is all I get. Zilch got ~ 10dB...
I am totally imbarrasssed, but in the interest of science I will expose my stupidity.
First, the circuit I am using is Zilch's except for the value of L3 in the hi-pass circuit (I didn't have a 0.08...