JBL 4410 rebuild

Joined
Aug 27, 2022
Messages
134
Location
Ste. Genevieve, MO
#22
I've been listening to these 4410's for awhile now and I thoroughly enjoy the detail in the music. I've been comparing them to my L36's and they are clearly not as sensitive as the 4410's though I still enjoy their warmth and musicality.
One disturbing thing I've noticed, when I play them together, it seems there is some lower frequency cancelation going on. Is that possible? How would I determine which pair is correctly phased? Neither pair seems out of phase with mids/tweeters in their respective cabinets. Any thoughts?
 

George S.

Veteran and General Yakker
Joined
Feb 18, 2020
Messages
5,033
#23
Do some reading about checking individual driver polarity using a small battery.
Then do some reading on the JBL sites about polarity connections at the crossovers for your model.
JBL did polarity connections somewhat differently from the norm on some models. Find the schematic.
My JBL Millenniums woofers and resonators had been re-foamed by a local business, and the prior owner reinstalled them with some wiring out of phase and with poor sealing.
A battery, the schematic, and some thin foam weather strip, and they were put right.
And finally, ensure your right channel is continuous through the system from every source, as well as the left. And ensure speaker wire polarity is correct from the amp to the speakers.
 

mlucitt

Veteran and General Yakker
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Jun 24, 2011
Messages
3,479
Location
Jacksonville, FL
#25
JBL polarity is opposite of most other speakers. + makes the cone retract while - moves the cone forward
Skratch knows what he is talkin' about:
In the olden days of speakers, the issue of whether the first motion of a cone was inward or outward, or polarity, was not uniform. Eventually it became standardized. Most speakers have an initial outward movement. When JBL started making speakers, they arbitrarily adopted reverse polarity and their speakers had an initial inward movement. This continued until JBL developed their musical instrument series speakers which used ¼” jacks. The use of these jacks required that JBL change their polarity to fit into what had become industry standards. Therefore, many of the older JBL speakers have reverse polarity, while newer models match what has become the industry standard.
The following is a listing of former and current JBL Professional systems and transducers by product category. In each category, models are indicated as positive or negative.

Musical instrument transducers: The following models are negative: E110-8 E120-8, 16, E130-8 E140-8, E155-4, 8. The following models are positive: M121-8, M151-8

Control Monitors: all models are positive: Control 1, Control 1 Plus, Control Micro Control 1AW/70, Control SB Micro Control 5, Control 10L, R, Control SB-1, Control SB-5, Control 12SR

Control Contractor Series Studio Monitors: All 4300-Series models (except models 4311 and 4312L, R) are negative. The following models are negative: 4406, 4408L, R, 4410L, R 4412L, R, 4425L, R 4430L, R, 435L, R. The following models are positive: 4206, 4208, 4311, 4312L, R, 4408A-L, R 4410A-L, R, 4412A-L, R 6208, DMS-1 LSR4300-Series, LSR-Series LSR6300-Series

Compression Drivers: the following models are negative: 2402H, 2404H, 2405H, 2426H, J, 2427H, J 2446H, J, 2447H, J 2450H, J, 2451H, J

Cone Transducers: the following models are negative: LE8T-H 2105H, 2118H, J 2123H, J, 2202H 2206H, 2220H, J 2226H, J, 2235H 2240G, H, 2241G, H 2245H. The following models are positive: 2012H 2020H, 2242H

Coaxial transducers: the following models are positive: 2142H, 2152H, 2155H

Cinema systems: 3000-Series systems; the following models are positive: 3622N, 3677, 3678, 3632, 3632T 3678-LF, 3639,

4000-Series systems; the following models are positive: 4622, 4622N, 4632, 4632T. 4000-Series systems; the following models are negative: 4670D, 4675C, 4675C-4LF 4765C-8LF

5000-Series systems; the following models are negative: 5671, 5672, 5672Bi, 5674. Cinema subwoofers; the following models are negative: 4642, 4645

Cinema subwoofers; the following models are positive: 3635, 4641, 4642A, 4642A-GS, 4645B, 4645C

Cinema surround systems: the following models are negative: 8330, 8333, 8340. Cinema surround systems: the following models are positive: 3310, 8325, 8330A*, 8340A* (*Note change from previous model numbers)

Application Engineered Series (Prefixes AM, AC, AL, ASB, SH): all models are positive. Architectural Series (Prefix AS): all models are positive Array Series (Models 4890A, 4892, 4893, 4894): all models are positive Cabaret Series (Models 4602, 4612, 4622, 4623, 4625, 4627, 4680, 4690, 4695): all models are positive.

Concert Series (Models 4825, 4828, 4842, 4845, 4847, 4850, 4851, 4852, 4853, 4860, 4861, 4862, 4863, 3866, 4870, 4871, 4872, 4873): all models are positive Control contractor Series: all models are positive

EON Systems (Prefix EON): all models are positive HLA Series (Prefix HLA): all models are positive JRX Series (Prefix JRX): all models are positive MPro Series (Prefix MP): all models are positive

Marquis Series (Prefix MS): all models are positive MR Series (Prefix MR): all models are positive Precision Directivity Series (Prefix PD): all models are positive Soundfactor Series (Prefix SF): all models are positive Sound Power Series (Prefix SP): all models are positive SR Series (Prefix SR): all models are positive SR Series X (Prefix SR): all models are positive SR Series II (Prefix SR): all models are positive SRX Series (Prefix SRX): all models are positive TR Series (Prefix TR): all models are positive Venue Series (Prefix VS): all models are positive Vertec Series (Prefix VT): all models are positive VRX Series (Prefix VRX): all models are positive.
 
Joined
Aug 27, 2022
Messages
134
Location
Ste. Genevieve, MO
#26
Wow. Scratch, Mlucitt, George S, thanks.
After reading those posts I did a quick and dirty polarity swap on the 4410's. No noticeable change by themselves, but when I added in the L36's there was a very noticeable difference in the low end. Could be the new voice coils are the same polarity as the originals.
Bonzo's Montreaux never sounded so good. :occasion7:
 
Joined
Aug 27, 2022
Messages
134
Location
Ste. Genevieve, MO
#27
Pulled the woofers and did the polarity check. Voice coils are built reversed. Reversed the wiring on the woofers, reassembled, connected to the amp correctly and now it sounds like the band is right in the room. Very clear, detailed, bass is crisp. No muddiness, no hump. Excellent low end. Don't need no loudness switch.
 

mlucitt

Veteran and General Yakker
Joined
Jun 24, 2011
Messages
3,479
Location
Jacksonville, FL
#30
127h-1.
I reconed both with a kit from Simply Speakers And applied aquaplas as the cones were not coated like the originals. I went with white just to be different. View attachment 77227
I had JBL 125A woofers in my L36 speakers and sent one out to be re-coned. It came back looking factory new, perfect. A few years later I sent the other one out to a different shop. It was a hack job, no gasket, the dust cap was off-center, poor workmanship. But it sounded good so I left it alone and both speakers sold along with the house.
You did good.
 
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