Hi everyone, recently bought these speakers in nice condition and curious about opinion of others who had an opportunity to listen to them.
Specifically interested in:
-are they easy or hard to drive
-amp matching experiences
-comparison with other speakers
-trebles extension “airiness”
-possible tweeter deterioration (is it ferrofluid based?)
-possible crossover upgrade, where to get the schematics if yes
My experiences:
Pro
-Lovely “organic” voicing (specifically lower midrange)
-size
Matching:
-not easy regarding treble extension
Against:
-airiness limited comparing to KEF Q350 or MA silver 50/100
Amps used:
-CA 851A
-Sony TA-F444ESII
-Nakamichi SR-3
-Sherwood AX-7030R
Specifically interested in:
-are they easy or hard to drive
-amp matching experiences
-comparison with other speakers
-trebles extension “airiness”
-possible tweeter deterioration (is it ferrofluid based?)
-possible crossover upgrade, where to get the schematics if yes
My experiences:
Pro
-Lovely “organic” voicing (specifically lower midrange)
-size
Matching:
-not easy regarding treble extension
Against:
-airiness limited comparing to KEF Q350 or MA silver 50/100
Amps used:
-CA 851A
-Sony TA-F444ESII
-Nakamichi SR-3
-Sherwood AX-7030R
I had a pair for a while, it's kind of on the way to the LS50. The uniQ driver is similar but not the same. The crossover is 2nd order on both legs from what I remember, unlike the LS50. Beyond swapping the power resistors and wiring I don't think there's much to be gained, KEF had it dialled at the price point. Like all low sensitivity, low impedance minis it needs current if you want to boogie. I certainly didn't find the treble harsh, but it's not forgiving. It doesn't sweeten everything like some lossy soft domes do.
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@simon dart
I understand they need a bit of power, both CA851A and Sony provide that I guess..
Would you be able to compare the treble extension to LS50s from memory?
I guess I am not into perfect linear response, loving “warmish” sound of these ones, but that sparkle is missing. I usually don’t crank up volume..
I understand they need a bit of power, both CA851A and Sony provide that I guess..
Would you be able to compare the treble extension to LS50s from memory?
I guess I am not into perfect linear response, loving “warmish” sound of these ones, but that sparkle is missing. I usually don’t crank up volume..
I also don’t understand the size of the driver according to specs, it’s actually 122mm OD (4.8”) instead of 130mm (5.1”). Rest of rubber surround (up to 130mm OD) is glued to frame, not moving at all, thus 130mm is misleading value..
The same is valid for Q350, where actual driver OD is 144mm (5.6”) instead of claimed 165mm (6.5”).
What they want achieve by these numbers??
The same is valid for Q350, where actual driver OD is 144mm (5.6”) instead of claimed 165mm (6.5”).
What they want achieve by these numbers??
This is what I was able to do..
The front baffle is healthy 32mm thick..
However I struggle to remove the crossover as the plastic pins are covered with some brownish stuff..
Has anyone any idea how to release the pins?
The front baffle is healthy 32mm thick..
However I struggle to remove the crossover as the plastic pins are covered with some brownish stuff..
Has anyone any idea how to release the pins?
That brown glue is horrible. I couldn't find anything to soften it, including alcohol, acetone or heat. I used side cutters to snip the tops off. When it came to putting the boards back in I just hot glued them back in place.
The extension is very similar to LS50s. They are both flat out to bat frequencies! One person's sparkle is another person's distortion. If they feel a bit dark to you, play with the value of the series resistor in the tweeter crossover. It's DIY after all!
Not good news then..
Maybe someone will have an idea..
I am scratching the glue out with small sharp screwdriver, but can not reach everywhere..
Maybe someone will have an idea..
I am scratching the glue out with small sharp screwdriver, but can not reach everywhere..
Oh, then there can be two issues.
My amps are not able to drive them or the tweeters are aging in case they are ferrofluid filled, which I don’t know. What amp did you use with them?
And third one, maybe crossover caps are aging, there is 8uF bipolar cap in crossover, the second one is unknown.
I have contacted KEF support with the questions about ferrofluid and crossover schematics, but did not get any answer from them..
I have contacted KEF support with the questions about ferrofluid and crossover schematics, but did not get any answer from them..
Touching this, I fortunately have also Q350s to compare. And Q350s are perfectly bright right, they just sound a bit “hollow” in comparison. Maybe boxiness is there too.
The lower midrange of R100s is what makes them pleasing to my ears. If R100s would have the clarity of Q350 trebles, then there is clear winner for me - R100s.
So I am trying to find out why it is just not there..
There would be perhaps the other way to go - trying to modify crossover in Q350s, but I am not confident with that.. For example to reduce bass extension and enhance lower mids, that the driver would operate in different range, that seems to be complicated, no skills to taylor the speaker voicing..
I doubt it's your amp not being able to drive them. Tweeters need almost nothing in terms of power from an amplifier. I use all sorts, from 100w AB to EL34 valve amps. The speaker will reveal the quality of your source pretty ruthlessly. It has enough resolution to do that.
I don't know about ferro fluid, yes it could dry out and drop the output of the tweeter. I don't know if it was fitted. Try and measure them, even if it's with a phone app and compare. The film caps KEF use in the tweeter crossover leg are unlikely to degrade drastically. No electrolyte to dry out.
Not sure what to try.
I have AstroAI multimeter, the woofer shows 3.1Ohm and tweeter 3.0Ohm resistance, that’s all I can measure hm..
There is one bipolar 8uF cap, not sure in what section, woofer or tweeter side. That one could be out of specs. The other one might be the film one on tweeter side, but I am not able to confirm that, no schematics, no crossover out to see underneath..
@simon dart I see, that from what amplification you used, they should be driven by my amps well, but still, as I said, there is no as near as good treble resolution compared to Q350s, so I am still puzzled 😉
@simon dart: What -technically/design wise speaking- is the difference between the R100 and LS50 drivers?
