Help with kef r900 issue

This sounds more like some kind of distortion, as one moment the sound is detailed, focused and beautiful, and the next it is a harsh, ripping or raspy, edgy sound bearing no “resemblance” to a human voice. Again, note this first happed with my original Mac gear, and continued....

Uh, what does overbright mean in this context?

I did hear them at a local Magnolia. 

It’s a big risk to buy without demo,if you don’t like the Kef sell them .what you're describing is typical to overbright speakers .Next time make sure to make a demo before buying.

Thanks! I have my opinions, and others theirs’, though I’ve decades of experience in the field of defending products.

I replaced a 20 year old pair of Martin Logan speakers with the R900, and offered a bargain price to the buyer so they didn’t go to a dumpster.

I may do the same with these as otherwise they are lovely to listen to, but I can’t live with this-it is as irritating as nails on a chalkboards! 😱

Unless someone has some non speculative opinion on cause and origin, I suggest we treat the issue as unresolved, but done. 

Hey OP, I hope you are able to figure out a solution that doesn't involve the nearest dumpster, and am delighted to read you used the word "idiopathic".

Tom

I should reiterate that the condition was first discovered with a McIntosh C15/MC202 combination and persisted unchanged with the Rotel RC 1590 and RB 1590.

Lastly, I’d like to thank everyone for trying to help. While the cause and origin may remain a mystery, I can’t live with it. In any event, I otherwise love the sound of the R900 and believe that KEF designs and manufactures great products. But, as with all manufacturers, things can happen....

The Doc is right: there is inherent risk in buying direct, and if you can accept that, it is fine.

Hey doc, I love the sound. Read closer: it manifests on other recordings.

Sum: they sound great until....

impeaching me begs the question, and the net worth test does, too. 

Thanks for your comments. 

Maritime, I can assure you there are 0 design defects with the current Kef R series, 

Please remember Kef is a very large company with extensive engineering resources, you may or may not like their sound but they do not design products which have eggregious flaws. 

Any company which has the engineering talent and testing and fabrication resources of a $100 million dollars plus a year company is going to make a pretty good product.

If you are having problems with the speakers it could be a bad crossover part perhaps or it could be something else with your chain. 

Perhaps the raspy quality is in the recording? 

It also might mean the clarity and voicing of the R 900 is not to your taste.

The R series is a very clean uncolored sound, you may prefer a less resolving loudspeaker.

This is why we sell mutlitple brands of loudpeakers and why we suggest buying from a dealer is always the better way to go.

Dave and  Troy
Audio Doctor NJ

Hey, doc, can you write a script for idiopathic distortion?  🏦🏨😩

Thanks, Dr.

My last email to KEF (the reference is to recordings I sent):


“Thanks.
Were you able to hear the sound?
Since my last email, I did substitute the new uni q you sent for the old one: the result is the same, if not slightly worse.
The effect is not limited to Mary Chaplin Carpenter, but (1) it is the worst found so far, and (2) I get identical results with the CD and a Bluesound Node 2 (same song, same places and times).
I’ve looked for sympathetic vibrations and discovered none. It is in both speakers, and clearly in the speakers, not a sympathetic source. By playing only one channel at a time, and standing directly in front of each, about a foot away, there is no mistaking it: it is a raspy, ripping sound, produced by each speaker, with the same music, in the same place or time, hence I must conclude it is either a design or fabrication defect in EITHER the uni Q or some OTHER component.
Believe me, I’ve tried what 50 years experience suggests and I can’t solve it.
Finally, to help others, be sure to inform them FIRST that there are TWO pairs of speaker connections, with Four connectors, not two. It helps to anticipate this on disassembly.
I must reserve all rights. I’m doing my best to mitigate but suggest there may be nothing more I can do.
By the way, my preamp is a Rotel RC 1590, and amp a Rotel RB 1590, connected with new Cardas XLR clear lights, and the speaker cables are new Transparent Plus. I got the same result in the left channel initially with a McIntosh c15 and mc202, with a Transparent music link, gen 1 speaker cable. I believe I overlooked testing the right side, but who knows....
I can’t justify throwing more money at better components when experience and reason strongly evidence a design or fabrication defect in some Component that makes up an R900 speaker unit.”

What at can I say, doc, I got burned. It certainly doesn’t make me feel better to state or imply the error in judgment was mine....😱

Of course, a component design defect would manifest in a similar manner, under similar circumstances, in all R900 speakers, though a fabrication defect would more likely be limited to contemporaneous components.

Maritime we are a long time Kef dealer, there is no way that if you replaced a set of drivers and the speakers are making the same distortion is it the drivers.

You may have a bad part in the crossover or there is something wrong with one of your components.

The likelyhood of both speakers having an issue is doubtful you need to go back and start checking your components.

I would borrow an amp and start there.

This is one of the reasons why buying direct is not a good practice if you have a local dealer then your dealer would be assisting you to resolve the problem.

Dave and Troy
Audio Doctor NJ

Both. Initially, I thought it was from one, but may have failed to isolate the other. Who knows, but I’ve now tested each in isolation, under identical conditions, and found the effect nearly, if not identical. 

 I dont understant . the issue coming from both speakers or just one ?

Good idea. I’ll give it a whirl. Thanks

Or maybe a quick youtube video demonstrating the issue and stating in the comments about what has been tried so far.  It is unlikely this symptom has never been heard before and others could offer suggestions. r900 not exactly inexpensive so would seem worth it to get some more ideas.

Just found this and wonder if my crossovers are the problem viz distortion:

http://www.audioexcite.com/?page_id=3614

In in any event, I can’t access them nor would I so KEF has lost a customer. The world will spin on....🙀

Thanks. Sometimes one has to move on. 

Sorry to hear about your situation maritime51. Wish I could offer some new advice, but I'm also a layman. 

Tom

Thanks. Kef sent me a new uni q driver and the issue remains. I suspect a design or fabrication defect, but I’m just a layman. I plan to get rid of the speakers as it is too distracting. 

Did you try replacing the 2 drivers with the concentric tweeter? It sounds like there is a midrange/tweeter defect. Get Kef to send you the 2 drivers.

Been there, done that-the warranty appears to be meaningless as a function of distance. That, alone, made me want to dump them, but I thought to ask here, first.

I mean really, they did send me a diy speaker...I feel so much better knowing that wasn’t the cure, and I am now fully sol.

Ive lived long enough to know that sometimes you make a bad bargain, and it is best to mitigate and move on.

I’m likely to move on, and never buy from this company again.

 I would try sending Kef a recording of what the issues are and maybe they can figure out and send you replacement parts with instructions for a DIY fix. Would stink to have to dump a new pair of speakers that are under warranty