JBL 4410A Tweeter Rebuild Experiment, Model 052Ti

[baco99]

Local AK member, Tayler Player, asked me to take a look at these Studio Monitors. They have all the makings of an amazing speaker, but with very utilitarian cabs. Great build quality, great drivers, and a classic 3-way JBL design.

The tweeters on these were completely burnt out, fried from hot swapping cables at an actual studio. In search of replacements, we discovered that JBL stopped making tweeters or diaphragms long ago.

So, here's a quick experiment. With nothing to lose, I pick up a set of Chinese made "replacement" titanium domes. They look the part and should be an exact fit. I plan to pop these in this weekend and see what they can do!

Pics....

Look at these crossovers!

Original tweeter domes.

Replacement domes.

More to come....

 

[baco99]

One done. Only thing I am not sure on is the polarity, the Chinese domes weren't marked... Not sure if the AAA battery trick will work since the domes are so small. Hard to see any movement at all.

Removing the old dome. You can see it's toast. Had to use a heat gun to loosen the adhesive holding it onto the cardboard, and a sharp blade to get under it.

Old vs new

Installation, test fit.

The leads on the new domes were too short to meet up with the spades, so I had to devise another plan.

Both new ones installed

I used some magnet wire that I had handy and created extension to the voice coil leads. Then Glued the wires down and taped any areas which could have contact with anything metallic.

One done, one to go.

 

[tensleep]

I am watching this thread with great interest. I have a pair of these speakers, in good shape, but I am always concerned about what to do if the tweeters fail. I have seen the knockoff replacements and have wondered about how they perform.

One think I notice right off the bat is that my tweeters, the 035tia, have the cross hatch pattern on the dome like your replacements have. Your original is smooth and you said it is an 052ti. I didn't know that anything but an 035ti or 035tia were ever used in the monitors.

 

[GordonW]

How did you align the voice coil in the gap? Shims? Test tone?

BTW: I've done similar things, with the dome/coil and magnet assembly from aftermarket dome tweeters. Seems to work pretty well. But, in my case, since I was using the dome assembly AND magnet from the SAME replacement tweeter, they were pinned together, and there wasn't any possible issue with the voice coil being out of alignment (rubbing the magnet gap)...

Regards,
Gordon.

 

[baco99]

By feel/ear. It's pretty obvious when things don't line up.

The back of the face plate has concentric rings marked on it. I lined up the dome with the rings, tacked it down, then put the cardboard cutout back on. The face plate has tabs that line it up with the magnet.

 

[Spooker]

Nice project baco. You can test your tweeters polarity by laying a small square of tissue paper over the dome when you hit it with the battery. Use just half-thickness by peeling it apart. You'll see the paper jump up when you have it right.....Spooker

 

[BMWCCA]

One think I notice right off the bat is that my tweeters, the 035tia, have the cross hatch pattern on the dome like your replacements have. Your original is smooth and you said it is an 052ti. I didn't know that anything but an 035ti or 035tia were ever used in the monitors.

The "A" series use the 052ti.

 

[baco99]

Got them both running. They definitely are benefitting from some burn in. I have to admit, however, I am not "wowed" by them. The midrange seems too forward and the bass is very boomy at 80Hz, 150Hz, and again around 250Hz. My guess is that these speakers require a good deal of equalization due to varied studio environments.

The tweeters are working, and they sound good, but are definitely over powered by the mids.

 

[baco99]

Ok, 035Ti tweeters were purchased and installed. HUGE improvement. FYI, the Chinese voice coil replacements were an interesting $12 experiment, but not worth the money.

 

[GD70]

This was an interesting read and experiment.
At least you did get them working. Any clue why they didn't sound as expected?

Glenn

 

[baco99]

This was an interesting read and experiment.

At least you did get them working. Any clue why they didn't sound as expected?



Glenn

Any number of reasons. The VC could have been a tenth of a mm too big/small. The VC wire could have been wound improperly. The VC could be too high/low as it sits in the gap. The dome material could be too heavy. I got what I expected for $12.

Believe me, The 035 were not $12!!

 

[BMWCCA]

I am watching this thread with great interest. I have a pair of these speakers, in good shape, but I am always concerned about what to do if the tweeters fail.

Make sure you're using adequate amplification and stop worrying about the tweeters. I can't even tell you how many I have and I've never had one fail.

 

[baco99]

The fireplace shot!

 

[davenportbuz]

The fireplace shot!

Hey Baco, I know you posted this just over 4 years ago! But I really like those stands you have under your 4410A's. May I ask where you got them? Strangely, it's not so easy to find a selection of stands online for that model.

Many thanks!

 

[baco99]

Hey Baco, I know you posted this just over 4 years ago! But I really like those stands you have under your 4410A's. May I ask where you got them? Strangely, it's not so easy to find a selection of stands online for that model.

Many thanks!

Hi! Those were $5 yard sale finds. Very simple 4 pieces of 3/4” MDF covered in black vinyl. They were sold in a lot of department stores in the 80s and 90s

 

[GD70]

Hey Baco, I know you posted this just over 4 years ago! But I really like those stands you have under your 4410A's. May I ask where you got them? Strangely, it's not so easy to find a selection of stands online for that model.

Many thanks!

Very simple stands. You could make yourself a pair in a couple hours.

 

[4343]

I had a similar experience with those China domes. I found the best ones are made for a PA driver and require removing the dome from the metal phase plug/mounting flange. When I got my 4412A's I was fortunate enough to get the last 4412 grilles and near the last 052Ti replacement domes from JBL Pro. Well, I ordered 4412A grilles, but the sent me 4412 ones, which fit identically.