I have a pair of the 104ABs that I gifted to a mate. They sound fantastic even after all these years, although I think it might be time to replace the capacitors on the tweeter circuit! Can't wait for part 2!
@@haycrossaudio5474 - yes, the crossover is a little different. I read that it was primarily to protect the T27 tweeter and allow the loudspeaker to handle up to 100W?
I love KEF speakers. Have a pair IQ3 and a pair RDM2. Since i am on budget my Sansui AU-719 was my best amplifier for years. Now i saved enough for a decent homebuild tube amplifier i understand what speakers really can do. The small KEF speakers are much bigger in sound now. When i went back from the tube amplifier to the Sansui, i thought there was something wrong with the amp. A very strange experience. It still sounds great but it felt very wrong after listening a few hours to the tube amp.
I had a pair of 104s, and I upgraded them to the aB (acoustic Butterworth) crossover. They were lovely! I used them in a recording studio briefly, but the T27 tweeters weren't up to producing enough volume in a properly acoustically treated room and I kept blowing them - but this was back in the '80s and replacements were readily available. I wish I still had them! My only reservation was that the BD139 aux bass radiator made deep bass a little muddy, so I moved on to reflex ported designs - Clearwater, anyone?
I had something rattling in one of my 104AB's; thanks for showing how easy it is to remove the speaker units. On opening, I found some loose pieces of black bitumin coated material. They were from the area around the tweeter. I presume I need to replace this somehow, but need help on what material to use. Can you help please? Speakers owned from new, bought in 1978, but not used for a few years.
@@haycrossaudio5474 The pieces are broken up. It all looks intact everywhere else. I'll try the neoprene foam. I'll check the other speaker to determine how much I need. Thanks for impressively speedy response.
In my opinion you should definitely change the treble filter to the acoustic Butterworth design - a significantly cleaner, more accurate sound, with improved imaging, and with polycaps it will sound much better again. As the client wants a bi-wiring option, you will be installing the T27 section components on a different board anyway. And why not follow through your very true observation that symmetrical baffles would be better and make a new one so that you can have the drive units towards the inside on both channels - that ought to improve imaging further; the client would then have a choice. It will be interesting to see what the effect of the dire state of the neoprene surround is - it could be the cause of some voice coil rubbing on the driver with distortion. Initially it could conceivably improve deep bass by lowering the free air resonant frequency, but things have already gone too far. If replacement surrounds of correct characteristics are available, then repair could be easier than finding replacement drivers - it's something those of us with Acoustic Energy AE1s (with foam surrounds) have had to learn to do. KEF drivers, as you say, normally survive fine, so this deterioration is surprising. (The glue on the edge of the baffle will be from the velcro which I believe held the original black acoustic foam in place. It disintegrated over time.)
I wonder if in the past the speakers and cones had been cleaned with a solvent that has caused the deterioration of the B200 surround and the stickiness on the B139.
The flattening of the surround on the B200 SP1039 use one these is typical and quite common. I've measured drivers with flat surrounds an ones with nice rounded ones and found extremely little differences in T/S parameters. And they sound the same. I haven't verified this but I suspect that the flattened surrounds will reduce the X-Max a bit and perhaps the linearity at high SPL but as T/S parameters are measured at very low levels, such an impact cannot be established by these measurements. And additionally, the original foam covers were attached to the front baffle by means of velcro strips that were glued on the front baffle. These appear to have been removed.
@@savvassidiropoulos5952 Correct regarding the drivers. Yes the residue was likely from velcro. I'll probably clean this up and add new to secure the new covers I need to make.
Might be interesting to replace the 139 ANRs with regular 139 drive units and connect a variable resistor across their terminals, thus you could play with damping for their use as ABRs
@@haycrossaudio5474 He is not suggesting having the B139 driven. Just to use one with a magnet and voice coil and use a resistor across the B139 terminals to tune the driver's Q. Similar to changing the weight put in the back of the cone for tuning purposes, but easier and quicker to change the tuning.
@@Mike81111 Really good. Recapped with SOLEN. Rewired with high purity copper wire and converted to bi-wirable. Much more detail and clarity. Better overall presentation. Its a shame these have that adjustment switch in the signal path
My Dad was gifted these back in the early 80’s, but it was the 104AB version which had a Fuse in the crossover.. They sounded sweet yet dynamic.. Were the AB versions older? My Dad gave them away to a family friend back in ‘91, but it already had some considerable damage then for various reasons..
@@rickg8015 not sure when the 104AB was released? Something is saying in the 80s so after the Ref104. The AB had a more complex crossover from memory. It's been quite a while since I delved into a pair
@@mfr58 Physically yes but beyond that I'm not sure as yet until I take the Cadenzas apart. The Cadenzas measure better so I'm expecting a more complex crossover? Stay tuned
@@frankgeeraerts6243 Looked at my books yesterday and I've had 4 pairs here over the past 2 years. Serial numbers were always random? They normally measure pretty close though so maybe?
@@haycrossaudio5474 depends maybe on the years when sold....mine were paired they said. I have one pair were the surround has come loose partly on the basket ..Witch glue should I use ? thanks Tweeters were often damaged by childrens fingers ....seen it more than once. On one pair I use the pepper like diffusing dome as used on the LS3/5..
Looks like the young team have been firing Gangsta Rap sub bass through the drivers 😂 . I saw a pair in cash converters that had bass units that were like wooly drawers in a swimming pool. Bought them for the tweets but the b200s went fap fap fap 🎉🎉😂😂
I remember B&W back in the 70’s supplying a frequency plot with each speaker so I think they were matching pairs at the factory.
I have a pair of the 104ABs that I gifted to a mate. They sound fantastic even after all these years, although I think it might be time to replace the capacitors on the tweeter circuit! Can't wait for part 2!
@@Luckiestmanalive-bb1mi I like the 104AB. A bit more refined. Crossover is more complex from memory?
@@haycrossaudio5474 - yes, the crossover is a little different. I read that it was primarily to protect the T27 tweeter and allow the loudspeaker to handle up to 100W?
I love KEF speakers. Have a pair IQ3 and a pair RDM2. Since i am on budget my Sansui AU-719 was my best amplifier for years. Now i saved enough for a decent homebuild tube amplifier i understand what speakers really can do. The small KEF speakers are much bigger in sound now. When i went back from the tube amplifier to the Sansui, i thought there was something wrong with the amp. A very strange experience. It still sounds great but it felt very wrong after listening a few hours to the tube amp.
When will part 2 be available?
Great video. I own two KEF REFERENCE 104aB myself and love the sound of them. I would love to do what you did, but I'm afraid to do it.
I think there was an upgrade option to upgrade to the AB crossover, from memory, this improved the treble response a bit.
I had a pair of 104s, and I upgraded them to the aB (acoustic Butterworth) crossover. They were lovely! I used them in a recording studio briefly, but the T27 tweeters weren't up to producing enough volume in a properly acoustically treated room and I kept blowing them - but this was back in the '80s and replacements were readily available. I wish I still had them! My only reservation was that the BD139 aux bass radiator made deep bass a little muddy, so I moved on to reflex ported designs - Clearwater, anyone?
I had something rattling in one of my 104AB's; thanks for showing how easy it is to remove the speaker units. On opening, I found some loose pieces of black bitumin coated material. They were from the area around the tweeter. I presume I need to replace this somehow, but need help on what material to use. Can you help please? Speakers owned from new, bought in 1978, but not used for a few years.
@@malcolmkenward2663 you could reglue the pieces that came off. Staple them to. If not self-adhesive neoprene foam 5mm will work
@@haycrossaudio5474 The pieces are broken up. It all looks intact everywhere else. I'll try the neoprene foam. I'll check the other speaker to determine how much I need. Thanks for impressively speedy response.
@@malcolmkenward2663 Gauge what you need off the other speaker if it's intact. You can get it from ebay. If you get stuck email me. I keep it
One of the few speakers were an ABR does work rather well............
Have several pairs of those ....still enjoy them.
Afternoon Matt👍👍
In my opinion you should definitely change the treble filter to the acoustic Butterworth design - a significantly cleaner, more accurate sound, with improved imaging, and with polycaps it will sound much better again. As the client wants a bi-wiring option, you will be installing the T27 section components on a different board anyway. And why not follow through your very true observation that symmetrical baffles would be better and make a new one so that you can have the drive units towards the inside on both channels - that ought to improve imaging further; the client would then have a choice. It will be interesting to see what the effect of the dire state of the neoprene surround is - it could be the cause of some voice coil rubbing on the driver with distortion. Initially it could conceivably improve deep bass by lowering the free air resonant frequency, but things have already gone too far. If replacement surrounds of correct characteristics are available, then repair could be easier than finding replacement drivers - it's something those of us with Acoustic Energy AE1s (with foam surrounds) have had to learn to do. KEF drivers, as you say, normally survive fine, so this deterioration is surprising. (The glue on the edge of the baffle will be from the velcro which I believe held the original black acoustic foam in place. It disintegrated over time.)
yes the velcro leaves a glue residue.
I wonder if in the past the speakers and cones had been cleaned with a solvent that has caused the deterioration of the B200 surround and the stickiness on the B139.
The flattening of the surround on the B200 SP1039 use one these is typical and quite common. I've measured drivers with flat surrounds an ones with nice rounded ones and found extremely little differences in T/S parameters. And they sound the same. I haven't verified this but I suspect that the flattened surrounds will reduce the X-Max a bit and perhaps the linearity at high SPL but as T/S parameters are measured at very low levels, such an impact cannot be established by these measurements.
And additionally, the original foam covers were attached to the front baffle by means of velcro strips that were glued on the front baffle. These appear to have been removed.
@@savvassidiropoulos5952 Correct regarding the drivers. Yes the residue was likely from velcro. I'll probably clean this up and add new to secure the new covers I need to make.
Might be interesting to replace the 139 ANRs with regular 139 drive units and connect a variable resistor across their terminals, thus you could play with damping for their use as ABRs
@@amok281 having both a B200 and B139 working in the same limited air space wouldn't be ideal at all
@@haycrossaudio5474 He is not suggesting having the B139 driven. Just to use one with a magnet and voice coil and use a resistor across the B139 terminals to tune the driver's Q. Similar to changing the weight put in the back of the cone for tuning purposes, but easier and quicker to change the tuning.
Interesting idea, but any degree of controlling of the emf produced by the voice coil would reduce the bass output of the speaker as a system.
@@hopefultraveller1 reduce := fine tune. When needed.
That air leak stuff may be why the woofers of my Celestion DL6's (series 2)are so sluggish. Will have to look in to that.
@@D1N02 Hope my explanation helped
How these ended up? I have 104ab coming next week.
@@Mike81111 Really good. Recapped with SOLEN. Rewired with high purity copper wire and converted to bi-wirable. Much more detail and clarity. Better overall presentation. Its a shame these have that adjustment switch in the signal path
@@haycrossaudio5474 Good to know. I have 104ab coming in so it would be nice to upgrade the crossover.
My Dad was gifted these back in the early 80’s, but it was the 104AB version which had a Fuse in the crossover.. They sounded sweet yet dynamic.. Were the AB versions older? My Dad gave them away to a family friend back in ‘91, but it already had some considerable damage then for various reasons..
@@rickg8015 not sure when the 104AB was released? Something is saying in the 80s so after the Ref104. The AB had a more complex crossover from memory. It's been quite a while since I delved into a pair
Is there a difference between these and the Cadenzas other than the switch?
@@mfr58 Physically yes but beyond that I'm not sure as yet until I take the Cadenzas apart. The Cadenzas measure better so I'm expecting a more complex crossover? Stay tuned
@@haycrossaudio5474 Oh, yeah, I forgot you have a pair of Candenzas waiting....
Usualy they were sold as a matched pair.
@@frankgeeraerts6243 Looked at my books yesterday and I've had 4 pairs here over the past 2 years. Serial numbers were always random? They normally measure pretty close though so maybe?
@@haycrossaudio5474 depends maybe on the years when sold....mine were paired they said. I have one pair were the surround has come loose partly on the basket ..Witch glue should I use ? thanks
Tweeters were often damaged by childrens fingers ....seen it more than once.
On one pair I use the pepper like diffusing dome as used on the LS3/5..
Looks like the young team have been firing Gangsta Rap sub bass through the drivers 😂 .
I saw a pair in cash converters that had bass units that were like wooly drawers in a swimming pool. Bought them for the tweets but the b200s went fap fap fap 🎉🎉😂😂
@@AndrewNeilBaird 🤣 I love your descriptions