Edgewound...JBL Pro Authorized...since 1988
Upland Loudspeaker Service, Upland, CA
Congratulations! Very nice work.
Out.
The color helps it blend in so that it doesn't look like a huge 2001 monolith in the living room.
This is such fantastic workmanship.
They look really nice!
Having made some primitive pete style cd racks recently in makeshift circumstances w/a router I can really appreciate how meticulous your woodworking skills are.
Freshly reconed drivers is basically like having some brand new 4345's. They will bring many many years of pure pleasure.
Welcome to the club &.... enjoy the hell out of them.
BTW: did you put a finish on them, clear coat & what kind of music do you mainly listen to?
Just Play Music.
Well, the 3145 is a 4-way with the upper 3 sections inverted WRT the woofer. Even when the biamp switch is engaged.
I am biamping, with a 3-way passive crossover, and I wasn't sure about the polarity so I decided to match the 3145, with the upper 3 sections inverted WRT the woofer. When I looked at it with the RTA, I saw a distinct dip at around 300Hz. I flipped the wires going into the crossover and it flattened out. Both channels were the same.
Now I'm wondering... given the phase characteristics of the 3-way crossover, should the top 2 sections be inverted instead?
Maybe I'm thinking about it too hard, I probably just screwed up the wiring somewhere.
Thanks guys!
Too bad, "2001 monolith" is what I was going for!
I sprayed them with Minwax Polycrylic. It came out alright, but I'll probably just stick with polyurethane next time (I avoided it this time because of the yellow tint).
As far as music goes, I like rock, but I listen to a little bit of everything. Mostly newer stuff, from the last 20 years or so.
Correct.
Correct.
Now that there, is interesting. The crossover from the 2245 to the 2122H is 290Hz - nominally where you've seen this anomaly with your measurement gear.
Interesting solution, but it might have dealt with the symptom and not the problem.
As we tend to say in these instances, "you can do whatever pleases", but this would be different from the OEM engineering.
Possible.
Clearly, you're deeply steeped in all this. However, may I be so bold as to humbly ask if you're aware of JBL's unique polarity convention? Unless you are, this could explain the anomaly (cancellation) you noted, right where you noted it. But, if, as I expect, I get enlightened by your reply, we'll have to dig a little deeper...
bo
"Indeed, not!!"
If you mean positive on black, yes I am aware of it.Clearly, you're deeply steeped in all this. However, may I be so bold as to humbly ask if you're aware of JBL's unique polarity convention? Unless you are, this could explain the anomaly (cancellation) you noted, right where you noted it. But, if, as I expect, I get enlightened by your reply, we'll have to dig a little deeper...
This got me thinking, what did JBL do in the 3155? The answer is that all 4 sections have the same polarity:
http://www.jblproservice.com/pdf/Network Schematics/3155 Network.pdf
I started searching for an explanation, and the answer has been in front of me the whole time:
http://www.audioheritage.org/vbullet...l=1#post240082
http://www.audioheritage.org/vbullet...l=1#post240590
Sorry, Mr. Widget, but I bet you knew it wouldn't be "for the last time" when you wrote that
I guessed you would. But it's all in how you use that knowledge...
Correct. But that is not what JBL did with the 3145.
I have not experienced the dip you described, and my networks are stock - so wiring is easy the OEM way. I'm suspicious that with your gorgeous networks and JBL's inverted polarity there is some unintended wiring snafu. But it doesn't matter, so long as you have resolved the anomaly and have your motors firing the way (i.e., direction) you want them to on (+) signal.
It was good to re-read that stuff. 3-yrs ago... Whoa.
bo
"Indeed, not!!"
I think their ugly!
NOT!!!!!!!!
Nice work
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