Find attached a pdf detailing the results from changing the crossover capacitors from my ~24 year old RL60's (apologies for the poor quality pictures but I compressed them right down to be able to load up in a single document).

What this shows is the equipment I used to measure before and after results for the capacitance (and their disapation factors) and before and after spectra of 10sec bursts of pink and white noise for speaker 1 (similar results for speaker 2 but omitted to maintain small file size).

I also recorded the same track (Song to the Siren - Tim Buckley) before and after. The net result was -

         I couldn't measure or hear any real differences during my audio tests. A few days later, when the removed capacitors were measured, the reason became obvious - the twenty four year old parts were as good as those I replaced them with.

I was so dejected - I had thought I was going to get the improvement mentioned many times here, the increased detail, the sharper focus and definition etc. - instead I got nothing. I'm just starting to get over it🙂

This of course does not mean that replacing old caps in crossovers is not necessary - I'm amazed that my devices survived all this time unaffected, it certainly isn't typical of electrolytic parts. My recommendation would still be if your speakers are old then go ahead and renew the capacitors in the crossovers😁

Puncher,

That really suprises me!!!!

Electrolytic caps do fail and die over time, just like an electrolytic automobile battery.  I noticed a tremendous improvement when I went to the higher grade Solen capacitors & Mills resistors.  It was like the speakers woke up after a long nap! 

Did you go back with the 63 volt caps?  That could explain why you didn't notice a difference.  I would use a minimum of 250v to 400v replacements caps.  The Solens I used are 400v.

16 years ago, I purchased an absolutely beautiful Baldwin Organ with all of the bells and whistles on it from a wealthy doctor for $100.  It had a huge bank of amplifiers inside of it.  When you would power it up and push any note on the keyboard, it would squeal or wail and none of the notes were what they were suppposed to be.  I knew it was broken when I bought it. I  would estimate it's value new was 2 to 3 thousand dollars or more.  This was a full size organ with beautiful woodwork and all of the console switches and bass pedals..

I turned it around and  faced towards my living room wall, and I started removing all of the banks of amplifiers, one at a time.  There were 6 or 12 of them.  It's been a few years and the ole memory is what it used to be.  I went through every amplifier in the organ and replaced every electrolytic capacitor with new "Orange Sprague" capacitors, which was a very long project.  I had another couple of hundred bucks in parts not counting labor.  When I got the last amplifier finished and reinstalled, I turned it back around and powered it up.  It sounded as clean as it would have if it were brand new.  I ended up trading the organ for a dual axle 18' trailer to the man that bought my last house because I needed the trailer to move, and he wanted the organ for his girls.

I'm really surprised you didn't notice an improvement, and yes, I agree with you,  while it's open change them out!

Mike

Hi Mike,

 The voltage rating od the parts should not affect their performance, although the 63V parts in the RL60's are marginal (~ 40Vac rating with the Amp of the BM5000 having 40V rails). The replacements were 100V rated devices.

An aged electroytic will shows itself first by an increasing disapation factor (tan d) which is related to it's ESR. As you can see from the measurements on the individual parts the old ones are as good as the new.

No - it would just seem that these parts survived  24 years and still within original specification - remarkable!

Puncher,

I agree that the 100 volt should be plenty.  I chose the 400 volt Solen caps because of their build and audio quality.  I've used them in many audio applications with outstanding results.  They are a French company and also have a build house in Canada.

This goes back to what I tell a lot of folks about audio.....It doesn't have to be textbook to work and sound great, meaning that your caps should have died like mine did, but didn't.....I broke some box calculation textbook rules with my subwoofers but they perform better than what the size of my enclosure is recommended for them, probably due to the use of the passive radiators.

This is what keeps the DIY stuff so interesting....😕

Mike

Puncher,

I just found your attachment.  I can't beleive how close those numbers are!!  No wonder you were disappointed! 

I don't know if this matters, but if your speakers were in storage and not being used like mine were, versus being hooked up and were used regularly, maybe that is what kept those electrolytics in good shape with yours?   Mine were dead.  I don't have the test equipment you have, but listening to mine before and after,  it was like listening to two different sets of speakers for me.  I'm impressed with your audio skills, test equipment, and spreadsheet results.  Thanks for sharing that with us.

Mike 

Puncher:

Hi Mike,

 The voltage rating od the parts should not affect their performance, although the 63V parts in the RL60's are marginal (~ 40Vac rating with the Amp of the BM5000 having 40V rails). The replacements were 100V rated devices.

An aged electroytic will shows itself first by an increasing disapation factor (tan d) which is related to it's ESR. As you can see from the measurements on the individual parts the old ones are as good as the new.

No - it would just seem that these parts survived  24 years and still within original specification - remarkable!

😕  Bit of a dark horse, you Puncher!

Oh, I'm not just witty and handsome you know!😎

Thanks for the compliments on my site.  I figured after ten years of speaker building projects for myself, it was about time to give back some of my free time to webmaster and host a free site to help others with my links, resources, suppliers & limited knowledge.

I enjoy helping others, and without the forums and other people "helping me out" while I was building and learning, I couldn't have the wonderful system I have the privelidge of owning now!  I've met a lot of unselfish people who have been very helpful to me.

Let's cool it with the praises to Puncher......he is on his third order of hats, and they seem to be getting smaller by the post.....

😕  Bit of a dark horse, you Puncher!
Mike, love your web site, keep it up[;)

Hey Puncher,

I called my Speaker Surgeon again, and they said they would replace the ABR rubber if "I" could come up with the replacement parts, in other words, if I would do all of the R & D to have a product that would be similar in compliance with the original ABRs, which is  what HI-FI and that other fellow in Demark are already doing.  They certainly aren't going to tell me what product they are using that would be a foolish business practice.  They weren't willing to go out on the limb to help grow their business unless they could profit at learning. 

They changed their tune a bit from a few days ago.  I told them I was prepared to bring them a speaker and the ABR already opened up to see if they wanted to tackle the job so they could get referrals from my site, my contacts, and the B & O forums. 

They said if I would pay them to do the R & D and repair my other pair, they would attempt it.  I reminded them I already had created a very good modification and had the extra pair of RL 60's for spare parts and had no intentions of spending any extra money.  I'm already doing a lot of work trying to help spread the news about my very acceptable modification and was only trying to help them get a reputation and more business to be able to rebuild them as well as helping the members of this forum.

I took it a step further.  I contacted the Houston Galleria Bang and Olufsen dealer and asked who their warranty and service center is.  He said they send their products to Austin Texas to Pyramid Audio.  I called Pyramid and got a very unfriendly person who didn't want his time wasted and said if I can't provide the part for him because they aren't available either to him, so he can't fix them. He referred me to Austin Speaker Service.  For the third time I got the same answer.....You supply me the surround part and we can fix them. 

I don't think there is a person in these forums that couldn't glue and trim a piece of rubber to a pair of plates if we knew which product to use. 

So, across the large pond from you I come up empty handed except for my modification that I am so happy with.

You asked me to let ya know what I found out; and now you know......😐

Mike