JBL 4312A & JBL 4401 Question - Need some direction please!

[lew123]

Hey everyone, hope everyone is doing well and it's ok to ask questions in this section. I had an account a few years ago but for the life of me can't remember the email/username, but it was low post count anyways.

I have a pair of JBL 4312A. They sound alright in my absolute amateur setup. I have 1 receiver and 1 power amp I've been using them on the past couple years. Technics SU-V98 and Crown XLS1000. I run them on the crown just because it sounds good to me and I figured it's the safest option for them. I have two questions for this set of speakers. I have a tear in one of the original woofers, can I still get that repaired or will it be replacing the cone? My second question is, the tweeters in these are really harsh and it doesn't seem to do anything with I adjust the High frequency level on either speaker, do I start with fixing those knobs or is it a lost cause with these specific titanium(I believe) tweeters? My last question for these speakers might be blasphemy, but I have a pair of Bose 301 Series II that just sound a lot crisper and prettier, and not quite as harsh at higher volumes, granted they don't go to the levels the 4312a's do. I'd really love it if these 4312a sounded like a bigger version of my little 301's. I know that's terrible to say so I apologize in advance.

Second, set of questions! I have a pair of sequential serial number 4401 speakers. I don't know how special that is but I don't want to get rid of them. One of them sounds ok, like nothing is drastically wrong, but it seems the woofer is extra bouncy. or it has too much movement. The other speaker only has sound coming out of the tweeter, doesn't sound good either... and the surround is completely gone and it looks like the cone isn't seated correctly. As in it looks side ways or is almost lose inside the cones housing. Are these repairable or can I replace the components with other parts and have a great speaker? I don't want to destroy history, but right now they aren't doing anything except collecting dust.

I love learning and hope to contribute one day to forum, but I am sorry to just show up again and start asking for information. Any direction or input is greatly appreciated.

 

[twiiii]

Well you need to find a Professional Doctor who specializes in repairing JBL. You can go to JBL's website for some help or you can look further and get JBL's professional web site service tech department and they will give you all the info you need. But don't be surprised if you have to wait for a reply. There is a list of discontinued drivers and discontinued repair parts, too.

Now if the Bose sound good to your JBL's are in definite need of help. ! This "ain't" gonna be cheap!!!!!!!!!! I would also be looking for L300's, 4430 or 4435. And be careful that Crown can get away from you. Your 4312 frequency response begins to fall off about 60 HZ and depends on room gain to reach 45 HZ. So like a Klipsch Hersey, they are pretty weak kneed. The 4401 is strictly a near field monitor with little bass below 70 hz.. Both should be placed against walls near corners to extend their limited bass capabilities. Neither are very efficient. Finding full range speakers that are fairly efficent in smaller cabinets is quite a challenge.

 

[lew123]

Wow I just did some Googling on those L300's, 4430's, and 4435's. I really grew up in the wrong era. I would LOVE to have any one of those 3 pairs but I saw $3k plus on all of them. Maybe one day! I guess I'll start on my 4312A's as far as repair since they get the most use. I went to JBL's website and emailed a couple of the repair people. I hope some of them do old stuff! I don't know why I think my little Bose 301's sound so good, maybe my other speakers are in that bad of shape! I'll let yall know if I hear back from any of the repair people. They are all at least 2 hours away from me so I can't just pop in. Thank you for the information, I really do appreciate it.

**edit** Would it be worth trying to repair components in the 4401's? and if it's not worth repairing, I assume it's not too terrible to replace original components with newer or different working components? They seem to have really nice well built cabinets.

Well you need to find a Professional Doctor who specializes in repairing JBL. You can go to JBL's website for some help or you can look further and get JBL's professional web site service tech department and they will give you all the info you need. But don't be surprised if you have to wait for a reply. There is a list of discontinued drivers and discontinued repair parts, too.

Now if the Bose sound good to your JBL's are in definite need of help. ! This "ain't" gonna be cheap!!!!!!!!!! I would also be looking for L300's, 4430 or 4435. And be careful that Crown can get away from you. Your 4312 frequency response begins to fall off about 60 HZ and depends on room gain to reach 45 HZ. So like a Klipsch Hersey, they are pretty weak kneed. The 4401 is strictly a near field monitor with little bass below 70 hz.. Both should be placed against walls near corners to extend their limited bass capabilities. Neither are very efficient. Finding full range speakers that are fairly efficent in smaller cabinets is quite a challenge.

 

[donprice]

Got photos? Post a few photos and you will get better advice on repairs. Much better.

Recones for the 4312A woofer will cost you ~$100 (or more) for aftermarket parts (plus shipping)...more than a few minor tears have been repaired with glue and tissue paper on the back-side of the cone for almost free. Try that first. Try backing off the mid-range L-pad to tame the harsh top end...it isn't always the tweeter that annoys you.

The 4401 is a nice little speaker. Well worth repairing if all it needs is a refoam. You are going to need to get a multi-meter and determine if the bad woofer has a burnt (open) voice coil...or a loose wire...or something else? A used replacement woofer is probably cheaper than a recone if it is toast.

Adding a decent subwoofer (or two) to a pair of properly functioning 4401 is not a bad plan if you can't tame the 4312A to your liking.

Last but not least, welcome to AK!

 

[lew123]

Yes I will try to upload some photos in this post. Thanks for the reply!
The following is all about my 4312A problems and I'll include 1 pic of one of the 4401's.
I did a little bit of testing I read on the internet to do, actually from another post on here!
I pulled each 035TI and checked resistance and got 0 or it might have said 1 but it was no change from leads not touching each other to when I placed them on the tweeter terminals. I also checked continuity and got 0, so in case my electrical terminology is wrong or confusing nothing changed on my meter checking resistance or continuity. I also read that it should be harmless to put 1.5v of power across each tweeter and listen for a click. I did this with a AAA battery and couldn't hear anything going on. Those were some things I read to check from audiokarma!

I also checked the voltage to the tweeters while they were on with a bit of music playing. This was probably a bad idea, but I made sure the terminals were not going to touch each other. I saw 0 voltage change on my meter with music playing when checking the voltage on the wires to the tweeter. So hopefully this was a bogus test, but I think something is cooked. What do you think? Thanks for taking the time to help me!!

Got photos? Post a few photos and you will get better advice on repairs. Much better.

Recones for the 4312A woofer will cost you ~$100 (or more) for aftermarket parts (plus shipping)...more than a few minor tears have been repaired with glue and tissue paper on the back-side of the cone for almost free. Try that first. Try backing off the mid-range L-pad to tame the harsh top end...it isn't always the tweeter that annoys you.

The 4401 is a nice little speaker. Well worth repairing if all it needs is a refoam. You are going to need to get a multi-meter and determine if the bad woofer has a burnt (open) voice coil...or a loose wire...or something else? A used replacement woofer is probably cheaper than a recone if it is toast.

Adding a decent subwoofer (or two) to a pair of properly functioning 4401 is not a bad plan if you can't tame the 4312A to your liking.

Last but not least, welcome to AK!

 

[lew123]

I just thought of this and thought I'd ask before I did it... Is it a bad idea to pull one of the tweeters from my JBL 4401's that I'm also working on, and plug it in to my 4312A's and see if any sound comes out? Thanks!

 

[lew123]

I just thought of this and thought I'd ask before I did it... Is it a bad idea to pull one of the tweeters from my JBL 4401's that I'm also working on, and plug it in to my 4312A's and see if any sound comes out? Thanks!

Well I may seem crazy replying to my own post. Sorry about that. I went home for lunch and plugged in one of my 034 tweeters out of the 4401 I'm working on and plugged it into each 4312A and it they both had sound coming out the tweeter. Also, each high frequency adjustment on the 4312A also worked. No wonder I wasn't thrilled about the sound. I had the mid range speaker trying to take up the slack of two dead tweeters. So I just need to get my 035TI tweeters repaired or replaced now I think. And fix my torn woofer then give them a listen again I guess?

 

[donprice]

Yep...repair or replace the 035Ti. Unfortunately repair is difficult since JBL no longer sells the replacement parts. No clue how the aftermarket driver or diaphragm copies perform. I don't think you can go wrong with the clone driver since it is a drop in replacement. Just keep the dead ones in case you sell the 4312A and they want the original drivers. The JBL habit can be an expensive one

 

[lew123]

Yep...repair or replace the 035Ti. Unfortunately repair is difficult since JBL no longer sells the replacement parts. No clue how the aftermarket driver or diaphragm copies perform. I don't think you can go wrong with the clone driver since it is a drop in replacement. Just keep the dead ones in case you sell the 4312A and they want the original drivers. The JBL habit can be an expensive one

Thanks for the reply! Do I need to test and make sure my cross over is filtering the lower signals correctly? If that makes sense? I ordered the replacements from Simply Speakers and they will be here tomorrow. I'm excited!

I know I tested and had sound coming out of the test tweeters I plugged in and the adjustment worked, I am just trying to avoid damaging the replacement tweeters when they are brand new. Thanks again.

 

[donprice]

Not sure how to test the crossover other than by plugging in the new tweeter and giving it a listen. If it sounds great, it is working.

Maybe you could try running some sine waves. Download the free version of TruRTA https://trueaudio.com/rta_abt1.htm

I've never tried it but I think a loud 60 Hz signal should give you no sound from the mid and no voltage (AC) at the tweeter (assuming you are testing at the leads with the tweeter not installed). Maybe someone will chime in with a better idea.

 

[lew123]

Not sure how to test the crossover other than by plugging in the new tweeter and giving it a listen. If it sounds great, it is working.

Maybe you could try running some sine waves. Download the free version of TruRTA https://trueaudio.com/rta_abt1.htm

I've never tried it but I think a loud 60 Hz signal should give you no sound from the mid and no voltage (AC) at the tweeter (assuming you are testing at the leads with the tweeter not installed). Maybe someone will chime in with a better idea.

Well my replacement tweeters from SS got here today. I popped them in and they sound really great to my ear. There's so much detail. I turned off my graphic EQ and have just been playing then adjustments on the speakers. Completely in love with the sound now! I think the woofers still might need some work though. Thanks for all the help!

 

[donprice]

Glad to hear that you got them running . Rock on

 

[SaturationPt]

The 4312As are a very nice speaker, very flat and accurate.

The woofers are NLA, as are the cone kits. Unfortunately the aftermarket ones are not going to be exactly the same and IIRC will also have black cones. Regardless, I'd replace them in pairs, keep the original woofers for resale value, and keep an eye out for a good used one (or pair). Occasionally a NOS cone kit comes up for sale on ebay (same with the original DR8035Ti diaphragm kits).

Regarding the 4401s, they are nice speakers, but don't have a lot of value. Watch for a pair of 4401s (or the consumer version: L15) with beat cabinets and you might be able to buy them for parts and repair yours. If you like the 4401s for their size but don't want to restore, sell them and buy a pair of L20Ts which have better high and low response in a similar cabinet. Probably cheaper than properly repairing the 4401s, a better sound, and you will have a pair of 035Ti tweeters! The L20T2 is similar but with a rear-ported cabinet has more restrictions on placement (but has the later 035Tia tweeter).

I'm also curious: Did the aftermarket 035Ti kits include damping pads?

 

[lew123]

The 4312As are a very nice speaker, very flat and accurate.

The woofers are NLA, as are the cone kits. Unfortunately the aftermarket ones are not going to be exactly the same and IIRC will also have black cones. Regardless, I'd replace them in pairs, keep the original woofers for resale value, and keep an eye out for a good used one (or pair). Occasionally a NOS cone kit comes up for sale on ebay (same with the original DR8035Ti diaphragm kits).

Regarding the 4401s, they are nice speakers, but don't have a lot of value. Watch for a pair of 4401s (or the consumer version: L15) with beat cabinets and you might be able to buy them for parts and repair yours. If you like the 4401s for their size but don't want to restore, sell them and buy a pair of L20Ts which have better high and low response in a similar cabinet. Probably cheaper than properly repairing the 4401s, a better sound, and you will have a pair of 035Ti tweeters! The L20T2 is similar but with a rear-ported cabinet has more restrictions on placement (but has the later 035Tia tweeter).

I'm also curious: Did the aftermarket 035Ti kits include damping pads?

As far as the 035Ti replacements, I just reread the description. It says they do not come with the rear gasket. Is this something I need to buy and add? I should have done more homework.

 

[roadrunnerx]

4312A's were the fastest responding speaker for it's size that I have ever encountered. But the low frequency does lack due to speed.
Very accurate.