IMF TLS 50 II driver replacements

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hi DIYA,

I acquired a fantastic pair of IMF TLS 50 II's recently and unfortunately some of the drivers have been replaced. They still have the original Audax 12X8 D25 tweeters and Kef B200 woofers, but the one midrange and the supertweeters are different. I'm looking for some input on what I can do about the midrange drivers because I am quite happy with the supertweeters. Unfortunately though the midrange was replaced with something that sort of was just slapped in and this needs to be remedied. It looks like the other midrange is still original.

If someone might be able to tell me what midrange the original driver is that would help.

Here are some pictures:

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.


Honestly, I'm not sure which one is the original and which one is the replacement!

Thank you for any and all help.
 
Last edited:
frugal-phile™
Joined 2001
Paid Member
Jeff,

Your pictures are linked to inside your gmail accout so we can't see them. If you could attach them to the forum (Go Advanced, Manage Attachments button)

The mids on there are Peerless K4040 (? not sure if the numbr without looking it up) in the cans, your pic will remind me of the superTweeter (Coles 4001?)

http://www.t-linespeakers.org/classics/TLS80/tls50.html

I've always wanted to get another set of TLS50s or 80s and do a rather "radical" upgrade. Replace the mid, tweeter & super-tweeter with a nice 3" full-range. On TLS80s, you could use the existing 4" cardboard cyclinder as an enclosure, on the TLS50 you'd need to fit one.

One would need to explore the possibilities wrt sensitivity and XO details, but the FF85wk would be at the top of the list.

One would need to redo the XO, either active or passive. The XO point between the B200 & the FR best choosen in relation to the box width / baffle step frequency (suggests 250-300 Hz).

dave
 
frugal-phile™
Joined 2001
Paid Member
snatched from elsewhere

attachment.php


dave
 

Attachments

  • tls50.jpg
    tls50.jpg
    78.5 KB · Views: 2,046
frugal-phile™
Joined 2001
Paid Member
With regards to the supertweeters, I'm not so sure if I do want to replace those. I don't know a whole lot about replacing components in speakers, although I am experienced with Car Audio.

Anyhow, what I'm worried about is the crossover. I'm no electrical guy and unfortunately I think modifying the crossover is a bit out to lunch for me for now, unless I must absolutely do it for the mid-ranges and then in that case would be a worthwhile venture for the tweets possibly.

What's your thought on that? I do like the supertweets in there right now so I'm not sure if it would be worth it to change them out.
 
OK so I think I actually managed to find a pair of Peerless K040MRF midrange drivers in working order!

However, I have heard there are two different types of this driver and only one is correct for the TLS 50 II's? Can someone confirm this? I read somewhere that there is a "can" type and that is not the right kind for my IMF TLS 50 II's.

Thanks.
 
frugal-phile™
Joined 2001
Paid Member
I have heard there are two different types of this driver and only one is correct for the TLS 50 II's?

attachment.php


Pull one of your mids and if there is a cardboard tube in bhind, then you'd prefer to have the open back version. The canned version could be installed. I don't recall whether the can can be removed or whether it is part of the basket. Jerry at Falcon likely knows.

I still think a 2-way with something like FF85 is the way to go.

dave
 

Attachments

  • Perrless-KO40.jpg
    Perrless-KO40.jpg
    148.2 KB · Views: 1,431
I agree, but unfortunately I'm just not much of a handyman when it comes to doing that much of a modification. I'm not into hacking up the cabinets and changing the location of the drivers, I'd rather just put something better in place to fix the mismatched midrange drivers.
 
I own a pair of the 50's and a pair of 40's. The pictures of the mids you are questioning look nothing like the ones in my 50's and 40's which are identical, which I can assure you are stock. I bought these speakers from the original owner, an elderly gentleman, the mids in the 40's need refoaming which also lead me to believe they are the original. I believe IMF may have used different drivers in the course of their evolution. I have noticed that particularly with the bass drivers I have seen pictures of.

I am a new member here, just joined. I was actually on the hunt for a pair of cole super tweets for my 50's, when I came across this thread. I know this thread is from May, but I could send pictures of the mids in mine sometime if that would help any...Terry
 
frugal-phile™
Joined 2001
Paid Member
Terry,

Pictures? Yes please.

The pictures of the mids you are questioning look nothing like the ones in my 50's and 40's which are identical, which I can assure you are stock

My recollections come from when we were selling these new at Sound Hounds. I always prefered the 50s.

I believe IMF may have used different drivers in the course of their evolution

They have.

I was actually on the hunt for a pair of cole super tweets for my 50s

You can buy those still brand new.

Drive Units

You'd probably need to get them from Jerry @ Falcon Acoustics in less than OEM quantities

Coles 4001G & Coles 4001K New Tweeter

dave
 
Hi Dave, thanks so much for the links to coles super tweets, not sure of the problem yet, all i know so far is the the tweeter and the cole flashed out at the same time. So far I have pulled the tweeter. Back to the topic, here are a few pictures of the mids in question, I believe these are the original, new here hope this works. Pictures wouldn't upload something about a security token, anyways looks like a nice place to hang my hat.
 
Well it only took me about 5 months since I first bought them, but I finally got them back to pretty much original status.

When I bought them they had replaced super tweeters and replaced mirange drivers (as seen above). Well, I've sourced out original midrange drivers and also replaced the super tweeters with Coles 4001's (16ohm). Not only that, I discovered these came with upgraded crossovers. Check it out:

An externally hosted image should be here but it was not working when we last tested it.


And here's how they look with their parts replaced:

An externally hosted image should be here but it was not working when we last tested it.


I think I'm a little spoiled with having two sets of IMF transmission lines, especially an upgraded pair. :) If you are thinking that you need to use electrolytics with IMF crossovers, I'm thinking not. I was convinced that you need to replace with electrolytic but the sound out of these is remarkable with their current crossovers. Well worth the upgrade IMO, they sound magical!
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.