KEF R3 bad woofer driver

[m_g_s_g]

Hi. After months trying to find a good deal on a discounted, open box or second hand pair of M105, M106, S400, Aria or R3, I have finally purchased a pair of second hand KEF R3. One of the speakers has been sold as defective with a "bad woofer driver". I assume that it will be out of warranty (no original invoice). I haven't received them yet. I'll have to contact KEF to buy a replacement, but maybe somebody can help me with a couple of questions:

- Are woofers serviceable / repairable somehow or buying a new driver is always recommended?
- Can the problem arise from a defective crossover? My plan is to swap the woofers, to test them with both crossovers.

Some KEF R3 specific questions:
- Can I get a different color woofer driver and change the aluminium cover? (golden in my case for the walnut finish)
- Would the price for replacement parts be significantly cheaper in EU? Any hints dealing with KEFs service/parts dept.?

Thanks!

 

[Rick Sykora]

1. Yes, if the damage is limited to cone/surround, a repair may be possible. If you can afford, would replace.
2. Unlikely the crossover is defective, but would test to be sure
3. No experience with KEF, but found B&W parts to be reasonable.

The KEF folks are likely to be helpful with a current model since they usually have parts. Check with them first and then let's see if you still have issues afterwards.

 

[617]

KEF uses high quality proprietary drivers. My limited experience with high end OEM drivers is that they cost more than what the equivalent level of performance would cost from e.g. Seas or Scanspeak.

One thing I can tell you about KEF is that there was a lot of interest from DIYers in buying their coaxial drivers (for use in custom speakers) which made them institute a policy of only supplying new drivers to owners. You'll certainly need a serial number to get a new woofer.

I could be wrong but replacing the woofer might a tricky job - they could be screwed in from the rear, but more likely than not they are fastened from the front, you just need to remove a trim ring. Good luck.

 

[waynel]

Take a look at this video at 3:18. The woofers are attached with screws on the front behind a removable ring.

 

[m_g_s_g]

I knew that the decision was somehow risky when I decided to buy, but I hope to learn on the way .

If you can afford, would replace.

It’s Ok, that’s probably what I’ll do. But since I’m not in a hurry, I’ll check what I can do with the woofer first. The seller told me that the driver replacement price is ~ 200$.

replacing the woofer might a tricky job

I found some instructions about how to remove the woofer. Indeed it will be tricky!

 

[m_g_s_g]

Take a look at this video at 3:18

Great! Video is better than text for this matter.

I understood that a car trim removal tool was going to be needed to remove the ring, but this guy manages to do it quite smoothly.

Let’s see how all this goes. I’ll receive them early next week. Thanks!

 

[thewas]

By the way, here someone can buy many KEF drivers which are usually not easy to get, interesting especially for DIY projects.
https://setelec-shop.fr/148-haut-parleur-kef?order=product.price.desc

 

[m_g_s_g]

[...]here someone can buy many KEF drivers[...]

This are great prices! I’ll wait for an answer from KEF, but this could be a very good option.

(Maybe) stupid question: would a pair of KEF R3 with internally disconnected woofer drivers work without damaging the crossover/amp? Kind of a pair of bass-shy LS50?

I guess that the R3 crossover has been designed to divert mid frequencies to the mid driver and bass only to the woofer, but I could be wrong. I know this would be far from ideal; it’s just to bring the speakers to an use for background music while I wait for the shipment.

 

[m_g_s_g]

I realize just now that I don’t even have to internally disconnect the woofers for that test: just un-shorting the bi-amp terminals would probably be enough.

 

[617]

This are great prices! I’ll wait for an answer from KEF, but this could be a very good option.

(Maybe) stupid question: would a pair of KEF R3 with internally disconnected woofer drivers work without damaging the crossover/amp? Kind of a pair of bass-shy LS50?

I guess that the R3 crossover has been designed to divert mid frequencies to the mid driver and bass only to the woofer, but I could be wrong. I know this would be far from ideal; it’s just to bring the speakers to an use for background music while I wait for the shipment.

The filters on the vast majority of passive speakers are in parallel, so they are independent of each other. Series crossovers would make such independent testing impossible, fortunately nobody makes them.

 

[thewas]

Using the R3 without a woofer connected wouldn't probably damage anything as I they are parallel crossovers but would make them sound worse than a kitchen radio as their mids are crossed around 300 Hz.
Edit: I see my answer overlapped with the one of @617.

 

[m_g_s_g]

My speakers arrived. Other than the bad woofer they seem to be in mint condition.

I’ve generated, saved and played several sweeps with REW, covering different frequency ranges (100-300Hz, 300-500Hz, 500-1500Hz,...) both for L and R, at a gentle volume level. The right speaker woofer is dead silent. All the other drivers seem to work Ok.

In the meantime I got a quotation from KEF USA for a woofer driver replacement. It is definitely more expensive than in Setelec, but still reasonable, and given the lower shipping cost, I think that I’ll order it here.

After those tests I’ve added my sub and I’ve played some non-bass-heavy music. Even with only the left woofer (but with the sub help) it sounded quite pleasing.

 

[jhaider]

Before you order a replacement, take the woofer out. It could be as simple as a loose quick disconnect.

 

[spacevector]

Before you order a replacement, take the woofer out. It could be as simple as a loose quick disconnect.

What I was gonna say. Check the connection from woofer to crossover board too. Good luck OP and congrats on cool new toys.

 

[BrokenEnglishGuy]

I had a distortion problem in my KEFs ( UNIQ distortion ) and they only had a thing a little bit loose inside, they went to tech support and just fix the thing for free

 

[617]

Yeah broken woofers normally...I should say almost always...still make some kind of noise, or move. If it's dead silent it may just have a disconnected terminal.

 

[m_g_s_g]

I was able to make more tests this morning. I swapped the woofer drivers from speaker to speaker, and the problem moved with the defective one. I also noticed today a very subtle "click" when the test tone starts to play and when it stops.

I'll order the replacement driver.

BTW: uninstallling the woofer driver is as easy as the above linked video shows. No need for special tools, but a car trim pry tool can help. A 5 minute job.

 

[617]

I was able to make more tests this morning. I swapped the woofer drivers from speaker to speaker, and the problem moved with the defective one. I also noticed today a very subtle "click" when the test tone starts to play and when it stops.

I'll order the replacement driver.

BTW: uninstallling the woofer driver is as easy as the above linked video shows. No need for special tools, but a car trim pry tool can help. A 5 minute job.

What was the process for ordering a new woofer from KEF? You supplied a serial #?

 

[LTig]

I was able to make more tests this morning. I swapped the woofer drivers from speaker to speaker, and the problem moved with the defective one. I also noticed today a very subtle "click" when the test tone starts to play and when it stops.

I'll order the replacement driver.

Before you do this could you

• check whether you can move the membrane in without a scratchy feeling
• measure the DC- resistance with a multimeter (the cheapest suffices)

 

[m_g_s_g]

What was the process for ordering a new woofer from KEF? You supplied a serial #?

I contacted them through the web and they answered with a quotation email from [email protected]. They didn’t ask for a serial #.

Maybe because I just need one? Maybe they have relaxed their policy of only supplying new drivers to owners?