Kef 104.2 Speakers. Suggestions Discussion Forum


KEF 104/2 SPEAKER OWNERS.

Lets have a tips and suggestions forum on how to improve these wonderful speakers.

Topics could include speaker placement, speaker tweeks, best speaker cables (interconnects, power cords etc), best amps (receivers, cd players etc), best compatible center and rear surround speakers, care and maintence, repair shops and more.

Here is a review (see below) that I found on the web concerning KEF 104/2 Speakers.

In over 10 years of doing high end audio reviews, enjoythemusic.com has given out a total of 59 awards for product excellence. The KEF 104/2's were among them. Out of those 59 awards, only 5 were to speakers and that includes speakers in the $10,000+ catagory. The editor has a section he calls "my personal list of products that deserve to be heralded as something truly special" and the KEF 104/2 speakers are included.

The Review summary: Back in the 1980's KEF was a wonderfully British company making their own drivers with a top-notch team. While their top range model was the 107 that produced deeper bass (down to 20Hz), after careful auditioning the KEF 104/2 was the obvious winner. KEF's 104 model saw various versions and the 104/2 was the final result of the product's evolution. This relatively high sensitivity loudspeaker, at 92dB/W/m at 4 ohms, produced frequencies from 55Hz to 20kHz (+-2dB) with five drivers. The tweeter is KEF's T33 25mm (1") silk dome with slight horn loading. It was flanked above and below by the B110 100mm (5") doped Bextrene midrange cone in a D'Appolito technique. Bass was produced by a pair of coupled cavity B200 200mm (8") paper cone drivers with their center magnets connected by a metal pole.

The midrange/tweeter/tweeter panel (weighting about 25 lbs) is completely removable from the woofer cabinet (at nearly 45 lbs) and both loudspeaker cabinets are very rigid. Each midrange is enclosed in its own sealed section to reduce any interaction while the tweeter is press fit to the cabinet via a rear screw. The internal woofers' output exits via a flanged port the same size as the midrange units. And thus the brilliance! The tricks up the 104/2; proverbial sleeve is that the sound wave of the midrange and the bass drivers is the same size, plus add in the point source-like output from the midrange/tweeter/midrange D'Appolito configuration.

As for sound, the highs are smooth and midrange is very well presented. Bass down to about 50Hz is excellent and tuneful. Do not use the KEF Kube, an external box said to enhance bass down to lower frequencies, as this clouds the sound. If you need lots of bass below 50Hz get a separate subwoofer. The soundscape thrown by the pair of 104/2 is remarkable! When present, not only is the sound totally enveloping, but you get height information too.
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I welcome and look forward to your input.
buyfast1
When I 1st started this journey during the early 80's my 1st pair of spkrs were Ohm Walsh 2's. Owned 'em for a few years than went for a pair of Kef 104/2's. A wonderful spkr, it was interesting to read the comment about the cube, I used it for awhile but wound up taking it out of the system, I felt it muddied up the overall sound. When I got the bug to upgrade I 1st picked up a loaner pair of Thiel 3.5's. Couldn't give 'em back soon enough, the spkr was too harsh to these ears. I wound up buying a pair of Spendor S100's and still own 'em to this day. Always have fond memories of the 104/2's. Don't know if it's due to all the discoveries within my new hobby that I was discovering back then (for instance, for better or worse, I picked up my 1st CD player, I've owned close to 2 dz. since then!) But I know it was a fine spkr, it's cool to see that it's still being discussed!
Does anyone have a KEF 104/2 MANUAL, that i can get a copy?

Does any owner have any suggestions for proper room placement of the KEF 104/2 speakers (such as distance from back and side walls, toe in, spikes or isolation footers, grills on or off etc)?

thank you
Per the manual-

"ROOM POSITIONING AND LISTENING WINDOW

As a general rule loudspeakers should be placed about 1 m from the nearest side wall and 50cm from the rear wall, and angling them inwards slightly can be beneficial. The distance between the speakers, and their distance from the listener is also important. Spacing the speakers between 2 (6'-6") and 4 (13') metres apart will allow images to develop fully, and you should sit at a distance at least equal to, and preferably greater than, the distance between them.

Considerable changes can be made to the sound of your hi-fi system by altering the position of the loudspeakers relative to the walls, sometimes by only a few inches. Changing the angle at which they are placed can significantly affect the focus of the stereo image.

The listening room is the most variable and unpredictable element in the hi-fi chain and it cannot be emphasised too strongly that the only way to achieve optimum performance is through many hours of critical, aware listening both on speech and music, whilst adjusting the speakers' position.

Removing the grille will not 'improve' the speakers' performance. The special design ensures best performance with the grille in place.

The Model 104/2 is designed to stand on the floor, it does not require any other form of stand or support. If the speaker is to be used on wood or tiled floor, use the feet as supplied. On thick carpet however, stability will be considerably improved by removing the caps and using the pointed feet, fig 8. Place the speaker in its chosen position and level it by screwing the rear feet fully in and adjusting the front, using the additional washers as necessary to level the speaker. Tighten the screw firmly when levelling up is completed. Only in rare cases of very uneven floors should you need to adjust the rear feet.

The tonal quality and clarity of the reproduction, and above all, the sharpness of the stereo image, are determined by the sound that reaches the listener directly, without reflection from walls, floor or ceiling.

Reflection from nearby walls, windows, mirrors, even the TV set can spoil stereo definition by confusing the primary image. Large items of soft furniture can cause absorption of midrange and high frequencies.

Electrical time delay in the dividing network is designed to tilt the listening axis up 10° from the horizontal. This ensures that the ears of a listener seated 3m (10') from the loudspeaker are on the axis, at a height of 1.2m (4') above floor level. Reference to fig. 9 will show that accurate stereo information is maintained over a wide area both horizontally and vertically. There is no one 'stereo seat' with Model 104/2."

Happy listening!
QUESTION TO KEF 104/2 OWNERS:

The Kef 104/2 speaker owner's manual discusses how to determine the correct polarity. Has anyone done this?

This is what the manual says: Correct polarity is vital to the proper operation of the system. Once you have made the connections described above (red and black speaker cable connections) you can check the polarity in the following manner. Place the two loudspeakers close together facing each other (2'-3" apart). Play a recording which has plenty of deep bass such as an organ solo, operating both speakers simultaneously with the amplifier switched to "mono". Repeat the test after changing over the connections on one loudspeaker. Correct polarity is indicated by firm, full bass. When polarity is incorrect, the bass will be noticably much weaker. Keep the speakers facing each other and, after establishing correct polarity as above, again reverse the connection on one loudspeaker. Using the same piece of music and keeping the signal in "mono", rotate the balance control on your amplifier on either side of "center". You will hear a point at which the signal almost disappears. At this point the output from both loudspeakers is the same. In an ideal symmetrical listening set-up this should be the setting adopted, (don't forget to corect the polarity change you have just made!). You may need to use the balance control to compensate for an "off center" listening postion, or asymmetrical speaker positions within the room. Model 104/2 imaging capabilities are outstanding and it is worthwhile spending some time in achieving the correct balance between the two speakers from your normal listening postion.
I found this information on the web (but it is not verified). Can any one verify?:

This relatively high sensitivity loudspeaker, at 92dB/W/m at 4 ohms, produced frequencies from 55Hz to 20kHz (+-2dB) with five drivers. The tweeter is KEF's T33 25mm (1") silk dome with slight horn loading. It was flanked above and below by the B110 100mm (5") doped Bextrene midrange cone in a D'Appolito technique. Bass was produced by a pair of coupled cavity B200 200mm (8") paper cone drivers with their center magnets connected by a metal pole.
Does any one know how to determine the age of the Kef 104.2 speakers based on the the serial numbers or some other method?

What is the best location arrangement (distance from side/rear walls, amount of toe in) for the Kef 104.2 speakers?

What is the best listener's position when facing the Kef 104.2 speakers? (e.g. speakers directed at the listener's ears, or listener positioned behind the speakers sound wave crossover, etc.)
What is the best location arrangement (distance from side/rear walls, amount of toe in) for the Kef 104.2 speakers?

What is the best listener's position when facing the Kef 104.2 speakers? (e.g. speakers directed at the listener's ears, or listener positioned behind the speakers sound wave crossover, etc.)

There is no one "best" way to position any speaker.There are too many variables involved.Only you can determine what sounds "best" to you.Experiment with some different placements and find what sounds "best" to you.
Hi-

Anyone know where to download an Owner's Manual for the KEF 104/2 speakers?

Specifically, I am looking for frequency response and impedance curves - hoping there in the manual...

Any help would be appreciated!
search 104.2 on the web and you will find a download
correction: manual for 104.2 is Not on the web
Try KEF archive for Manual
Follow up:...go to KEF USA...then go to 'About KEF'...Look for Museum then go to the '80s and click on KEF 104.2. Info straight from KEF....still not manual though...
I have a circa 1990’s pair of non-bi-wire KEF 104.2’s that I purchased recently. I have wanted a pair since they came out and was able to obtain them for a steal.
Of course, I wasn’t aware of all the caveats involved with owning a pair of these until after I had them for a while.

I have already replaced the rotted inner surrounds on the woofers (the outer surrounds are rubber). I also had to scrape the dried-up ferrofluid from the tweeters, which increased the high-end sensitivity, but of course has most likely changed the response from the original spec. I ordered a pair of replacement tweeters from KEF but have yet to install them.

I have read that replacing the caps in the crossovers is the next step in restoring these speakers and will be a better match with the new tweeters.

Does anyone offer a kit to replace the caps? If not, can anyone recommend what and how many to get?

Any other tips or advice would be greatly appreciated.

Thanks!
Greetings KEF 104/2 owners past and present.

I'm wondering if any of you have explicit instructions on how to remove both of the internal woofers inside of the KEF 104/2s that you can send me or post here? My uncle has a pair that sound great but when I took a flashlight to look at one of the internal woofers in the port hole with him the dust cover of the driver looked rotted out. The upper one may be rotted as well. If the 104/2s still sound good should the internal woofer still be replaced? Thanks
I contacted KEF (at sales@kefamerica.com) and received a quick response and attached was a copy of the "Installation Manual" (aka, Owner's Manual).
Contact me (or KEF) to get your copy...
Hello again to KEF 104/2 owners past and present as well as fellow A'gon members. I'm in need of some thoughts again. A pair of KEF 104/2s that I got were dropped off to SG Custom Sound in NY for a check up and inner foam repair of the interior woofers. (I tried to do it on my own but it was too daunting for me when I inspected the internal woofers.) Now SG Custom Sound got back to me and said that the internal woofers had really bad issues with the voice coils. When he tested them he found they were shot. The voice coils were rubbing together and they may have been overpowered previously. Since they are beyond repair does anyone have any recommendations regarding replacements for the internal woofers from either KEF or other reputable manufacturers? Again your thoughts and opinions are appreciated. Thanks
This should cover a number of questions in this blog.
I recently established a listening room for my old KEF 204.2 (Now about 20 years old) and they sound fantastic. I'm powering them with the Emotiva mono-blocks 500W/side (emotiva.com) and the added power cleaned up the sound stage. My room is not ideal as it's about 13 ft square. The ideal speaker placement for me was on the 8-5 line; 60" from the back wall to the face. Tape a diagonal line on the floor out from each corner intersecting a point 5' from the side wall and 8' from the back wall. Then plce the front center on the line, 60" from the back wall to the tweeter face. For me, that's about 8.5' between the speakers. The sweet spot is also 8.5 feet back making a equilateral triangle. Now, a laser line shot across the top of the speaker (center) should intersect just 2-3 feet behind the listening chair.
Once speakers were set, I had to trim the KUBE. Some advise not to use it but I found sound was MUCH better with; without everything went flat. However, I run with Bass Extend OFF and trim the bass to -2 (db?). This opened up the sound stage.
Tweek1: Sound dampling panels on the side walls at the first and second reflected sound points (a mirror leaned on the wall ans positioned between chair and speakers shows 1st point on R wall when you can see the R speaker; second when you can see the L speaker will be closer to chair. Same for L side. My cheap panel was a 2'x4' T-bar ceiling panel made of fiberglas insulation; plastic face.
Tweak2. I had 12 ga wire and I doubled up with a new 10 gage speaker wire-Python2 brand; really opened sound stage.
Tweak3. I added sound traps in the front corner. My cheap panel used (2) 2'x4' T-bar ceiling panel (made of fiberglas insulation; plastic face); glued together, framed and suspended at a 45 degree angle; 4" out of the corner and 4" down from ceiling; suspended by 30# fish line; long side up and down.
Tweak3. I took my Paradigm Sevo-15 sub into the room but timmed it to only enhance below 50 Hz. Phase needs to be set first with a sound meter and test tones.
The process took several months but I have been richly rewarded.
Recently I auditioned speakers in the 10-15,000 range and did not notice a compelling improvement!
Throw away the Kube and get a sub.

Really a very nice sound, particularly in the midrange.
One way to improve mine would be to repair them! With one of the mids (!) the code is delaminating from the rubber surround. Sounds at moderate levels does not *seem* effected (greatly), but I have not tested at higher levels. Obviously should be fixed, and looks likely to be easy by simpling using a needle-type glue applicator to get between the two, and then, with the rear removed, gently squeeze them together. Probably best to do one spot at a time. Question is: what kind of glue is appropriate for the bextreme / rubber interface?
Thanks.
OK so since my last post, I have now replaced the tweeters with the substitutes currently offered by KEF. They brought back a lot of the sizzle that was missing and so far I don't find them harsh.

However, after repeated listening, I started to notice that one speaker had a slightly different timbre than the other, i.e., brighter. At first I chalked it up to one speaker being near a wall and the other next to an open space, but this ultimately was not the cause. Needless to say, this was messing with the imaging, enough that it started to really bother me...

I sent white noise through them in mono and there was definitely a difference between the 2 upper midranges. The left speaker was slightly brighter than the right. At this point, everything I read led me to believe that the crossovers were most likely at fault, since the originals can drift out of spec over time causing the speakers to sound a little dim.

Some time later, a pair of crossovers from a similar-vintage 104/2 came up on eBay for cheap. The owner was parting out an older pair as he found a different pair in better cosmetic condition. I scored them figuring I could at least use the spare parts.

After a good deal of procrastination, knowing just how fun it is to work on these monsters after having servicing the woofers myself, I finally decided to swap out my existing crossovers with the "new" ones. This is no easy feat, as this particular iteration has the crossovers mounted on the inside rear of the cabinet, but it can be done. I was able to remove the crossovers and have a good look.

At this point, I think it's worth mentioning that all the Capacitors on my original crossovers are KEF-branded. I read that these caps are actually manufactured by ALCAP, but the ones that meet the required specs/tolerances are then branded with the KEF wrapper. However, all the caps on the "new" crossovers were branded ALCAP and look to be original, i.e., no evidence of desoldering/resoldering different parts. There was also no evidence of leaking caps or corrosion on either set of boards.

So, after a full afternoon of groaning and scraped knuckles, the new crossovers finally in place and both speakers all buttoned up, I gave a listen...

They sound EXACTLY like they did before. The upper midranges still have a slightly different tone from each other and the left speaker is still slightly brighter than the right. What a bummer.

My next step is to actually swap the entire Mid-Tweet array from one speaker to another to see if this "brightness" follows the driver or stays with the cabinet. I should note that I had done this before and could have sworn the brightness stayed with the cabinet, which is why I was convinced the crossovers were the culprit. You could argue that the new crossover has the same issue as the old one did, but how likely is that?

I was really hoping the problem was not to do with one of the midranges themselves, because they are pretty much non-serviceable.

I have never read anything about ferro-fluid drying up in anything other than the original tweeters, but as there is no buzz or other evidence of a damaged midrange, it almost sounds like the issue I had with the original tweeters, where the fluid dried up and caused them to sound very dim.

Does anyone know if the midranges also used ferro-fluid?

Any other ideas or suggestions about what to do next would be greatly appreciated!

Thank you for reading.
I finally ordered a pr of the modified Morel tweeters from the guy on Ebay (KEF tweeter). $249 incl shipping may be too rich for some but hey, the 104/2 were $2400 - $2900(rosewood) in the 80's! The new tweeters are incredible & are exactly per KEF spec - 92db 4 ohm - & dropped right in. They are 80w drivers so no worries on power handling. I tried all the "fixing", ferro fluid etc. I have to tell you this guy nailed it & in the trash the SP1191's went!
Thanks for sharing your information. I found the seller you are talking about. I'll definitely make note for when the tweeters go bad on my 104/2s. A couple of years ago I had Scott from SG Custom Sound replace the ferro fluid on my "Rosies" and so far the tweeters are sounding fine.

Also putting this out there for anyone else who may not want to spend the $249 + shipping for modified Morel tweeters.

Madisound speaker store has the Morel MDT29-4 (4 ohm) Textile dome tweeters available.

They just have the tweeters only though. All the rest to make it plug and play ready for the KEF 104/2s are not included.

To Rdeckard: Any luck with your issues with your KEF 104/2s?
Just curious about the sound difference in the new morel tweeters. Would it be worth it for me to upgrade my tweeters.
After trying the Morel and Vifa , I finally broke down and ordered the recommended replacments from KEF (part # R1548X) and I am very pleased. They're 160 a pair, but to me this is the way to go if you want to get the most out of these wonderful speakers.
Hi Aqualung

Where does one order the KEF R1548X? Did you get the tweeters directly from KEF? Thanks and advise when you can.
Wanted to let folks know that I had my 20 year old T33-Sp1191 tweeters cleaned and ferrofluid replaced (see e-bay for this service) and never knew how good these speakers really are! Apparently the ferro fluid in T33 tweeters slowly dries out, leaving s gummy residue which greatly reduces the tweeter output. It happens so gradually, you never notice a change.

I had tried some Vifa 5/8" dome tweeters at about $20 each while the T33's were out being "refreshed". They seemed like a definite improvement, but were not the least bit integrated into the "voice" of the speaker once I heard the fixed up T33's.

So... if you like the speakers but think they are overly "laid back" it may well be caused by "gummy" tweeters which only put out a fraction of their intended volume.
Questions:
1. What is the best Wood Polish (and/or cleaner) to use on the Kef 104/2 cabinets (or should we NOT use any polish or cleaner)?

2. The Kef 104/2 loudspeakers have either an A or B, after the serial number on the back of the cabinet. I have read that these speakers are supposed to be matched for sound at the factory, but some people have said that they can hear a difference between the A and B speakers.
So, does placing the A (or B) speaker cabinet in the left or right listening position, improve (or change) the acoustic experience?
Hi Buyfast1

I'm glad you participating on this thread again and Thanks for starting it.

For my older Rosewood KEF 104/2s when I have more time to clean them I'd use Old English cleaner. For a quick cleaning I dust the KEFs first and then use Pledge Orange cleaner/polish with the proper clean rag/cloth. I haven't seen any adverse affects with using these cleaners with my KEFs. Maybe other members who have experience woodworking can advise.

For your second question regarding A & B placement of the KEFs. With my 104/2s I've always been particular with placing the A & B order properly but with my KEF 103/3 which were easier to move I inadvertently put them in the wrong order. I put the B speaker 1st instead of the A speaker and I didn't notice any improvement or degradation of the acoustic/listening experience.

Thanks again
i used to use tung oil, which (unlike most commercial polishes) actually seals and protects the wood, in addition to giving a nice sheen. it's also long lasting--a quick coat should still look good after a few months.
I have a set of KEF 104/2's...I got them at an antique mall in WHEELINGW.Va.For 50.00$$!!They are in very fine condition. I replacedthe nonfunctional dome tweets with 2JBL titanium dome tweets.They fit perfectlyand reproduce high range superlatively. I Have them hooked up to an SAE 2401. 250 watt per ch.Power plant.They are playing in conjunction with a pair of AR-90 tallboys w/a McIntosh MC-2300 power plant......Awesome.Buff said???
Captain, was there a model number for your JBL's?
The JBLtweeters I put in the KEF104/2 are from a pair of JBL-L-80T,3-way,floor standingspeakers I "parted out"due to exteriorcabinet damage. They are exactly the same size magnet structure.
Hi CaptainJazz

I'm a KEF 104/2 owner as well and the tweeters in my 104/2s just needed a ferro fluid replacement luckily.

From looking online I found the part number for the JBL tweeters you mentioned.

JBL-035TI

Is this tweeter you used in your KEFs? The only e-tailer I found that sells copies of the JBL tweeter is Midwest Speaker Repair.
The JBLtweeters I put in the KEF104/2 are from a pair of JBL-L-80T,3-way,floor standingspeakers I "parted out"due to exteriorcabinet damage. They are exactly the same size magnet structure.
I am a musician, and have a lot of home and professionalpower amps...I hooked my KEF 104/2's to the new penultimate Yamaha 600/600(@4ohms)pro.Amp.It is a new dimension in listening...........The KEF's sound surrealistically transparent and reach amazing, explosive transients with unstrained,undistorted accuracy dueto the high headroom.I did have a Sansui BA-5000 power amp hooked up to them.(300/300 wpc)these KEF's need high headroom to sound their ultimate.
I would like to trade my KEF 102/5 vintage reference speaks-For a set of vintage Acoustic Research AR-90 or Acoustic Research AR - 9 loudspeakers... My KEF's are in very good condition &all drivers are functioning perfectly. Anyone interested should call 304-559-4558....I alreadyown one pair of AR-90 s.