HELP! Hi-Fi Answers August 1975 TLM dimensions.

[webby]

Hi all,
I'm reading this thread with great interest, I have the same dilemma.
I bought some Cambridge audio r40 speakers until I could fine some r50 or IMF tsl80, the problem is the second hand value appear to be increasing rapidly and becomes less viable for me. So what to do?
I found some HiFi answers cabinets on eBay, I pick them up tomorrow. I can use the same crossovers and drivers but won't have the supertweeter.
After reading info out there I understand the crossovers are the weakest link, the cabinets could be better optimised by mjk calculations.
My current thinking is to buy a minidsp 2x8 crossover and umik for measuring and room integration.
I am using classd tpa31162 to good effect, cheap and easy to implement.

I would really like a large tl kef revisited design☺can you help?
Maybe a mjk triangulated, and a tl mid for the b110?
Would be able to hear what these drivers are capable of without poor crossovers and hampered cabinets.

Or changeable baffle to replace the t27 b110 combo with something modern.
What do you guys think?
Cheers
Ian

 

[surv1v0r]

I am veering away from the Hi-Fi Answers TL and towards the B J Webb design. As to your not having the supertweeter, it has been suggested that this is perhaps something of an indulgence so perhaps try without one?

You might want to look at Falcon Acoustics' DN12 crossover replacements?

I also wonder about the wool damping material, keeping it "fluffy" and in place sounds like a nightmare - surely there are better solutions by now?

The good news is that I may have got a better quote for supplying, cutting and routering the cabinet material and as frequently suggested here I will probably use 18 mm Ply rather than 25 mm MDF

 

[Colin]

The wool damping material is a hangover from the original designs and is one of those areas where the myths of TLs persist. There are alternatives in the US which aren't available here in the UK. In a Scanspeak TL I build some years ago, I tried the long haired wool and then tried BAF wadding, with little apparent effect on the sound. The BAF was easier to handle, could be stuffed into place and didn't require moth-proofing.

PMC line their TL walls with reticulated foam but they are presumably acting more like a reflex.

http://www.southaudio.com.tw/PMC New ATL FB 1i 001.jpg

 

[bonesetter]

I too am reading this with interest. I've owned a pair of the R40's since 70's and yes the wife wishes they were small speakers, but I explain to her that the footprint of stand mounted small speakers would take up just as much space . Just don't let your wife see the tiny Bose speakers with Sub.

The crossovers use the same board for R40 & R50 I believe and iirc the impedance curve of the XO are fairly flat apparently reflecting on good design.

I rebuilt mine with Solen caps and uprated bass coils onto insulation board and mounted them into wooden boxes with 4mm connectors onto the outside of the cabinets at the back.

The Solen caps did make an improvement to the sound and worth doing. https://www.solen.ca/pub/index.php?catalog=3&niveau1=1&niveau2=3&s1=2&s2=3 Falcon acoustics supplied components iirc don't know whether they still do.

One thing to be careful with is the polarity connections of the drive units to the XO. the B110 is in reverse polarity to the T27/B139. Best to check with a small battery and notice the cone excursions.

The black felt around T27 is worth doing according to Falcon but I never got around sticking mine on!!

The speakers are mounted on 18mm MDF plinths which are spiked into wooden floors.

I remember the Rogers HiFi answers very well and somewhere have a copy of the design booklet.

I've also pondered on selling the aging R40's and have looked at these IPL ACOUSTICS HIGH QUALITY SPEAKER KITS which seem very tasty and may well be a good modern alternative to the old KEF speakers.

Mike