TDL Reference Standard Repairs

[c-atle-79bay]

Hi All, I picked up a set of TDL reference standards, and despite how good they sound I do have some issues that are going to need corrected to make them perfect.

1st - All domes have been pushed in, but new domes diaphragm and mounting plates (no magnet) that seem like likely matches are available on ebay, and the important detail he has enough for a full set of 4. They look the same, I have no proof they are the same, and know of 1 difference, mine say they are 16ohm on the magnet structure and he lists his as 4 ohm. I have not measured the impedance on the diaphragm it's self. I was also able to push all of mine back out, with only 1 crack. I've had it suggested that I can use resistors to adjust for this, anything else I can do, any downsides to that suggestion? The seller apparently bought the remaining stock of the IMF factory in Michigan.

2nd - One of the woofers has a bunch of nasty looking corrosion like battery acid stuff on the terminals and the leads are green, it moves freely but does not play any sound at all, again I have not tested it with the multi meter but plan do as time permits, any advice on cleaning the leads? I wiped the white stuff off and it did not seem to be any more than surface stuff but it did not change anything, Any other ideas to fix after more diagnose? And what would I actually be looking for in a diagnosis?

Any other advice thoughts or requests are welcome, I want to make these guys sing and go all in. Until my SO buries me in them that is.

Thanks

 

[sax6]

Whoaa... I've googled for a pic of your speakers.. Geez, these are ( beautiful ) beast !
Just looking at the crossover kind of picked my curiosity.

Sadly, I have no wisdom to help you with tackling your problem.

Just wanted to let you know >>> these speakers I would like to have <<<<

Good luck !

 

[Nat]

Very much worth restoring, among the better speakers you are likely to encounter. That corrosion looks ugly, but my suspicions are focused on the solder joints. Dab them with rosin flux (not acid flux!!!!!!!!) and reflow them. See if that helps. If that doesn't do it, check the solder joints where the tinsels are soldered to the voice coils wires (usually where they go through cone). You might need to replace the tinsels, and if that is beyond you, repost (maybe in the bartertown area) -- I imagine there are people who could do it for a reasonable fee.

 

[JimPA]

More than likely the TDL woofers are 16 ohm both wired in parallel to achieve an 8 ohm impedance.

 

[GuyK]

I wonder if whoever soldered these originally used acid core solder or flux. You might try neutralizing that with a solution of baking soda and water, then re-flowing all the joints.

 

[c-atle-79bay]

Here are some images of my pushed out domes and new kid grills, the ones you see closeups on, are on their 2nd smoothing, as I'm now calling it. I used my thumb nail to smooth them from the inside out. The grills are from a set of mini speakers that I had been keeping around, I used 3m double sided black tape, the thick stuff, hope it holds, if not will tack the corners with some rubber cement, not ideal, but, I prefer that small spot to the alternatives of destroyed tweeters. Now if i could just get the 3 1/2 year old to not be so interested in silver shinning disks in the HUGE MONSTER SIZE BOXES, I'd be fine, but I'm not an idiot....anymore.

 

[mech986]

Very nice repair, they look a lot better.

 

[baco99]

Nicely done. Thats a very acceptable and economic solution.

For the woofer with the corrosion on the leads, it's highly likely that the corrosion has eaten through to the copper tinsels. This happened a lot in the early 80s with speakers I have seen from Allison and others. The solution is to fine some good copper on the tinsel lead and "jump" a very the wire (single strand) form that to the terminal. The woofer is probably still good with the exception of the leads losing contact.

 

[c-atle-79bay]

Bumping my own thread question about matching impedance on dome tweeters, are there any major downsides to doing such? Sorry to bump, but only 6 left on that site and seriously thinking of making a grab since the condition of mine are soso after the repairs. The issue is the magnet shows 16ohm so i assume the tweeter diaphragm will also be 16 ohm, the diaphragm and faceplates available are 4 ohm.

Thank you

 

[canuckaudiog]

Bumping my own thread question about matching impedance on dome tweeters, are there any major downsides to doing such? Sorry to bump, but only 6 left on that site and seriously thinking of making a grab since the condition of mine are soso after the repairs. The issue is the magnet shows 16ohm so i assume the tweeter diaphragm will also be 16 ohm, the diaphragm and faceplates available are 4 ohm.

Thank you

If the originals are 16 ohm and you plop in 4 ohm domes you will mess with the crossover point. However, it depends on how they're wired. I imagine they're wired in parallel so they would present an 8ohm load. I wonder if you wired the 4ohm drivers in series it would result in the same thing?

 

[c-atle-79bay]

If the originals are 16 ohm and you plop in 4 ohm domes you will mess with the crossover point. However, it depends on how they're wired. I imagine they're wired in parallel so they would present an 8ohm load. I wonder if you wired the 4ohm drivers in series it would result in the same thing?

Any downsides in adding additional resistors at the tweeter it's self to present as a 4ohm load is my concern, and of course how to figure out the wattage of resistor needed. But in the end is adding a resistor at the speaker just a different form of cross over modification and likely no downsides? If I choose the correct value that is.

 

[TLS80]

Just noticed this thread. I believe that Jerry Bloomfield of Falcon can repair your GT3021/3 woofer. Verdigris deterioration of the leads is the likely issue.

The RSTL's create a very wide and deep stereo image. They need to be decoupled from the floor.I put three Vibrapods under mine. Doing that made an audible improvement in bass clarity.

There is a Yahoo IMF Electronics group that might be worth joining, too. Also pnwas.org.

Hope this helps. If you ever want to sell yours, let me know. Congratulations on your purchase.

 

[mech986]

welcome to AK, TLS80, an apt name!

 

[c-atle-79bay]

Thanks TLS80, right now, and really forever, my location for them in not ideal in terms of the floor, it's fir on sleepers crossed on concrete sleepers with plenty of bounce. The room is 35x14 and I'm occupying the last 12x14 space. It sounds good, but I doubt as good as it could given a better configuration. I've started the topic of room treatments with my SO, and think I have wiggle room to make some improvements. Here is a space photo for grins.



I'm going to try and get the woofer out this weekend, and test the continuity of the tinsel, if not conducting I'll try to clean the tinsel in place with salt/vinegar then baking soda solution. Beyond that may just have to bite the bullet and order one from Falcon. I did read that one of the drivers is 8ohm and the other is 16ohm and this was done for better performance, if that is the case, then I'd imagine I'm missing a fair bit of bass.

 

[mech986]

If you're having a driver problem, supposedly DHS speakers in Saginaw had the last of the IMF/TDL driver stock, and has been selling it off on Ebay. They may / may not have experience with repairing the TDL woofers but most speaker repair shops can easily re-tinsel drivers given enough care and experience. I have not worked with their repair service personally but it may be an option given they are in the US. of course, other speaker repair services like MillerSound and others (like JBL authorized pro service centers) probably could do the re-tinsel work as well - I know Orange County Speaker Repair did that and more when they were in business.

http://dhsspeakers.com/index.html https://www.facebook.com/dhspreakerrepair/

 

[c-atle-79bay]

I've actually got a really good repair place right next to my office, however I think I cheesed him off, will try to reach out again. Hate to ship.

 

[c-atle-79bay]

Still did not get out my woofer this weekend, typical, but did get some listening in, and not sure what to think, listened to Pauls Boutique and 3 Minute Rule

leads with ping pong balls bouncing, my former main speakers IMF "The Studio" really high lighted this sound, perhaps to a fault but I'd gotten so use to it, that I now find it almost missing in the TDL's. I'd also noticed this in a steely dan song form 2 Against nature a few particular details were missing. On the flip side, the effortless low to high transition of the TDL's still is amazing. Trade offs, always trade offs. I'm running the speakers are a spectro accustics set which includes and EQ, will try to play with this and some of my more familiar music, but first need that woofer out. A note about spectro accustics, this stuff is WAY undervalued, and and sound excellent.

I contacted DHS and they were very helpful, the issue with the woofer was common, he has the parts in stock, doing a set right now in fact, so timing is good. He also suggested how I could use the 4ohm diaphragms to replace my existing 16 ohm versions, now I just need to figure out the wiring change. Will also pull the remaining woofer to see if any other show the same symptoms.

 

[c-atle-79bay]

I've changed my amp section to an HK990 that I recently had repaired. The difference is quite remarkable detail has increased markedly, and the level I was able to drive these speakers too was starting to scare me and I had my kids in the room and was worried to go any louder. But it was CLEAR and strong and louder than I'd ever had anything. The McIntosh and Spectro acoustics gear is both great, but now I feel like I have a more stable ground to analyse the TDL's and it's apparent I'm going to need to repair or replace my super tweeters. I tried to isolate them and listen without them, but the liveliness of the music suffered I'd rather have 1 good and 1 bad than none.

I was wondering if anyone is familiar with the tdl version of the celestion hf2000 to know if the diagram is the same? Or a good alternative? The Dayton amt's look interesting.....

 

[audiomagnate]

I personally would try to keep them stock. Contact Falcon Acoustics for proper replacements.

 

[c-atle-79bay]

I personally would try to keep them stock. Contact Falcon Acoustics for proper replacements.

Should have mentioned no luck on that route. They will have replacements for other TDL drivers but not those....sometime next year.