ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hi All,
I just thought you'd be interested...
For a while now, I've been experiencing some distortion with my BL5 speakers - first one of them started exhibiting the issue - it got worse over time. Then the other one also started sounding distorted. The distortion was apparent in the midrange.
The distortion was so bad that it was possible to record it on my phone:
https://www.youtube.com/shorts/YpUXh3eHeHI
I spoke to a B&O repair technician, who originally suggested that I might need new chassis for the speakers. I can't say I was too pleased at this news!
However, I decided not to accept this, and try my own DIY analysis, as it's such a pain to ship the speakers around the country and I didn't want to fork out for new chassis!
So, I removed the chassis on the worse speaker. I carefully inspected the electronics. I have to say, the chassis is "beast" in one respect - there's a lot going on, but in other respects the class D amps are incredibly compact, particularly considering the amount of power they can produce!
I didn't find anything wrong, apart from some very slightly blown capacitors on the bottom board. The bottom board is the power supply for the sub bass/bass driver amplifiers. So I replaced these capacitors - the originals were ELNA 160V, 2500uF 105 deg C. I notice that such capacitors have a service life of about 2000 hours at 105 degrees C (as far as I was able to determine). I replaced them with EPCOS 200V, 2700uF, 5000 hrs at 105 deg C. Hopefully they will last the remainder of the lifetime of the speakers! I'll replace the capacitors in the other speaker when I can. I think it's good preventative maintenance.
No other capacitors were blown and everything else looked ok on the other boards.
Some photos I took while working on the chassis are here: https://photos.app.goo.gl/hWFTCyB1HqyGjues8
So... I decided to delve deeper. I removed the acoustic lens parts from the speaker and tried powering the midrange driver with a known-good amplifier. I immediately noticed the same distortion, so my current supposition is that the mid range drivers are faulty on both speakers. Unfortunately, this means I definitely need to take the speakers to an authorised repair technician to get them replaced. I'm taking my speakers there next week. Wish me luck! I really hope this fixes them. I will update this thread when I get back!
The new mid range drivers are £120.96 + vat each, plus fitting and calibration at £152.05 + vat. Significantly cheaper than the chassis exchange price of £430.38 + vat each, with fitting/setup at £85.15 + vat!
I just thought people would be interested to follow my journey of getting my fabulous BL5's back into rude health again.
Andrew
Hi
I dont know if you know it, but if you will change in your chassies for a replacement, the dealer or service parter could not get excenge module price if you have done some own replacement on the chassies. Thats mean you need to pay a very high price to get a new chassies, compare if you let B&O make the fix for the chassies from the start.
But hope your replace of the capacitors will hold longer:) as you say, seems you have good skills for replace, but I only inform you so other people her in the forum think one more time before they start to fix them self. =)
And hope you get the mid range driver replace and fix:)
Good look with your BeoLab 5.
Glad this sounds like it’s not a chassis.
For the record, when I had my BL5s, I went through an upper tweeter when I heard distortion. I had both replaced to keep them the same as it were.
Apart from hearing the obvious distortion, pushing test tones through should give a clear indication of damage - though not definitively. I would expect the driver to be distorted if that was the fault and assume no sound would be a EPROM issue.
You had me at Renault 5 Gordini... I didn't see anything else
9 LEE: You had me at Renault 5 Gordini... I didn't see anything else
Haha! Yes - I have been a fan of the Renault 5 Gordini (Turbo) for 20+ years! Sadly, I sold my Gordini Turbo this year. I have a Turbo 2 though (you can find it on YouTube - it's the black, highly customised one reviewed by JayEmm on cars and Motor Addicts).
Thank you to all of you for your replies. I am indeed concerned that replacing parts on my chassis means it cannot be used for exchange later on. However, I can always refit the original capacitors before exchange! I'm also a huge DIY fan, and I can see how it might be possible in (20+ years), when parts are no longer available, to do some DIY work to re-engineer the BL5. I've done a lot of DIY electronics and am currently looking at class D amplifier designs for my classic car project. I could imagine that an off the shelf microcontroller and DSP could be embedded in the BL5 and it could send the various signals to the different driver amps, upgraded ICEPower or even something else. The power supplies are perhaps the most challenging part of the design, but you can buy ICEPower amps with integrated power supplies.
A suitable microcontroller could be a Teensy with its audio board and a DSP. A computer with a calibrated mic could be used for setting the equalisation parameters.
Anyway, I digress. Fingers crossed that the replacement drivers fix my problems!