Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Multi-Way Conventional loudspeakers with crossovers

Cambridge Audio R50 and Rogers Monitor repair
Cambridge Audio R50 and Rogers Monitor repair
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 28th June 2013, 01:53 PM   #21
fborden is offline fborden  Netherlands
diyAudio Member
 
Join Date: Nov 2012
Hi ParalabFan,

you won't be disappointed with the result of the Xover filter. I love the sound.

Frank
  Reply With Quote
Old 28th June 2013, 04:07 PM   #22
ParalabFan is offline ParalabFan  United Kingdom
diyAudio Member
 
Join Date: Apr 2013
Location: North Derbyshire, UK
A good day to post that comment. I have just got mine up and running, couldn't wait to get the cabinets finished fully, Getting used to the sound, deeper and faster bass that my LNBs with a Dalesford 8" driver but it should be like that! The mid range and lower treble seems a lot more forward and is taking a bit of getting used to. I will be posting pics and comments to my thread very soon, so keep an eye out for new posts on my thread!

Last edited by ParalabFan; 28th June 2013 at 04:09 PM. Reason: spelling
  Reply With Quote
Old 7th August 2013, 02:00 AM   #23
muckel is offline muckel  United Kingdom
diyAudio Member
 
Join Date: Aug 2013
Default HiFi Answers/Cambridge R50 TL Monitors

I built a pair of these in the 70s and to this day have never heard anything close to them. I had to abandon them in a house in Amsterdam in the early 80s. (No one strong enough to help me get them from the 4th floor).
Considering building another pair. The question is, can one use the Kef B164 instead of the B139?
Personally I thought the Coles/T27 combination caused coloration in the stereo image and would like to be able to adjust their levels or combine the top in a single unit....
I'm aware that Wilmslow Audio do a top of the range crossover based on the R50 and there are 'replacement' units for the other Kef units.
Anyone done a comparison?
Can I use B164s instead of B139s?
  Reply With Quote
Old 13th August 2013, 08:28 PM   #24
stuart booth is offline stuart booth
diyAudio Member
 
Join Date: Jan 2013
Stick to the original specs. as you say you've never heard anything close to them.
Stick to the Kef/Coles units and get hold of the Falcon Type 53 crossover. The 2 HF units are commoned at the crossover, but you could easily attenuate one or other if you still feel it is necessary.
  Reply With Quote
Old 20th November 2013, 07:07 PM   #25
Fabiolander is offline Fabiolander  France
diyAudio Member
 
Join Date: Aug 2013
Hello,

I repaired a pair of R50 few months ago and I can tell you I never eerd something good like these speakers.

I share here with you my experience :

BEFORE and DOCS


An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.

An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.

An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.

An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.

An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


[Update 08/08/2013]

An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


Pub Cambridge Audio
An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


Full Size
https://dl.dropboxusercontent.com/u/...dvertising.jpg

Schema
An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


https://dl.dropboxusercontent.com/u/...le-JerryB.jpeg

An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


https://dl.dropboxusercontent.com/u/...Manual.01.jpeg

https://dl.dropboxusercontent.com/u/...Manual.02.jpeg

An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.
  Reply With Quote
Old 20th November 2013, 07:18 PM   #26
Fabiolander is offline Fabiolander  France
diyAudio Member
 
Join Date: Aug 2013
Here inside the beast :

An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.



An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


some work to do :

An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.
  Reply With Quote
Old 20th November 2013, 07:25 PM   #27
Fabiolander is offline Fabiolander  France
diyAudio Member
 
Join Date: Aug 2013
AFTER CLEANING

An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


Coles Tweeter were HS so I biiught new ones :
An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.

An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.



I rebuild filters with Mundorf and russian Capacitors
An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


I changed he connectors

An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.

https://dl.dropboxusercontent.com/u/...8Custom%29.jpg

And Finally ;-)

An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.


An externally hosted image should be here but it is no longer accessible. Please upload images instead of linking to them to prevent this.
  Reply With Quote
Old 20th November 2013, 07:33 PM   #28
Fabiolander is offline Fabiolander  France
diyAudio Member
 
Join Date: Aug 2013
So I hope it will give you some courage to continue
  Reply With Quote
Old 24th May 2014, 02:56 PM   #29
lawrence001 is offline lawrence001  United Kingdom
diyAudio Member
 
Join Date: Dec 2010
Location: London UK
Quote:
Originally Posted by 48kg View Post
First of all i am only trying to help!

I was fortunate at the age of 24yrs in 1972 working at a shopfitting company in Sittingbourne Kent UK was able to cut and assemble these R40 & R50 speaker cabinets for the Cambridge loudspeaker company.

I am now 65yrs and 41yrs further on i had to wait to only just obtain my first pair of original R50`s.

When each person assembled these speakers when finished there initials were written inside on the bottom and mine have JW and John worked on the bench next to myself so i would of helped him take these speakers to our large press when assembly was complete and the glue was all wet ready for it to cure which took about 2 1/2 hours, the press was right next to our heater so curing in all weathers was no problem.

My initials are KG so some of you may have those written on the inside of your own speakers cabinets.

The drawings in the .pdf ones do have some errors other than that pointed out. The Major one is the fact that a groove 12mm x 5mm deep and being machined from 75mm down from the top of the front baffle plate on the right side looking at the front extends to within 12mm of the bottom so the air does not escape! The groove is 22mm in from the edge because of the softwood fixing battens.

This groove is to easily enable the connecting wires from all the speakers and the crossover in the top void to escape down to the base void and to the rear of the cabinet for external connection. The whole front baffle plate with speakers can be assembled on the bench and when soldering completed the groove has a sealing putty like substance pressed over it so when assembling the front completed baffle to the cabinet the putty seals the groove with it`s wires where it crosses the dividing panels for the different voids thus keeping them airtight to one another.

This is an easier and more professional way than drilling holes for wires into each void and aralditeing each hole. It also enables all to be completed on the bench.

The Super Tweeter recess hole in the front baffle is 3" and NOT 4"

The 2" x 1 1/2" softwood batten in the bass void goes front side to side and is not a "T" shape with part going to the rear of the cabinet. We used to use this to lift with one hand and steadying the top of the cabinet with the other when removing them from the press.

I am at the moment renovating my R50`s back to original as far as possible.
I have replaced the end edges veneer with iron on Teak wood veneer instead of contact glue and plain teak veneer. To give the aged look or Patina stain the new teak with Georgian Medium Oak stain and apply some French polish and wire wool and wax polish after hardening. The finish on the side panels was always Shellac which was sprayed on to give the French polish look.

I hope i have been some help to those thinking of making there own speakers from those very fine drawings. Of course time moves on but this is how they were constructed from 1972 to 1976 at our factory.

Keith Graham
Quote:
Originally Posted by ParalabFan View Post
Great to see another R50 in bits.

I am also starting to rebuild a pair but the campartment filling has been moved about, if you haven't already take a look at my thread "Cambridge R50/Ex Baobab speakers".
I am trying to find out how all the filling is suposed to fit correctly, apart from the stuff shown in my pics there is a roll and sheet of what looks like carpet underlay. Have you taken the foam off the front of yours and if so can you help?
Keith

I was very interested to hear that you made the cabinets for the R50s in the 70s. I recently bought a pair myself but they are not up to the standard of the Cambridge Audio made version. The main panels are white melamine faced while the sides and backs (where showing) are just painted gloss white. The front is not a single panel but split into two, one for the two HF units and one for the mid and bass, the gap between them forming the end port of the mid line, this being the full width of the speaker. Inside it does have the right wool filling and uses chicken wire to keep off the bass driver.

Now the seller told me he got them off a friend who worked for Cambridge Audio in the 70s and they were a prototype. I didn't think much of this story when I looked at them as they were very much home-made. However when I managed to get to the crossover I found that the capacitor values were not the same as those on the circuit diagram and I think it's unlikely that someone who made them up at home would go to the length of playing with the crossovers, so I think there may be some mileage in the story after all. Perhaps Cambridge played with changing the values before going into full production. I was
wondering if you were aware of the existence of any such prototype speakers from your work with Cambridge.

Incidentally rather than change back to the standard values (as the inductor values are unmarked this could potentially have a very strange effect on the crossover points) I replaced all the caps with individual equivalents from Wilmslow audio and they sound lovely. The nicotine staining on the melamine could not be cleaned well and hence I took the decision to cover them in wood effect vinyl as a temporary measure while I consider other potential options in the long term.

Thanks, Lawrence
Attached Images
File Type: jpg image.jpg (337.8 KB, 73 views)
  Reply With Quote
Old 27th May 2014, 07:27 PM   #30
lawrence001 is offline lawrence001  United Kingdom
diyAudio Member
 
Join Date: Dec 2010
Location: London UK
Whoops I should have said falcon acoustics not wilmslow audio.
  Reply With Quote

Reply


Cambridge Audio R50 and Rogers Monitor repairHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
cambridge r50 crossovers tonysherwin Multi-Way 1 15th October 2014 07:21 AM
Cambridge R50 Tim Smallwood Introductions 3 30th March 2012 03:09 PM
cambridge r50 tonysherwin Multi-Way 5 7th July 2008 10:13 AM
R50 Cambridge Audio :) PhaseLockLoopy Multi-Way 2 27th May 2008 10:37 PM
Cambridge Audio A5 repair help BongFish Solid State 1 20th February 2008 08:32 PM


New To Site? Need Help?

All times are GMT. The time now is 06:50 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki