Bang and Olufsen type 6501

[Mazeppa]

Some additional RL-140 observations.

The fella I got the tweeter from agreed to my request to send me the enclosure he had pulled the drivers and crossover from for sale on e-bay. It arrived with the grill cloth missing which was cool as the primary reason for obtaining the enclosure was to develop a method to replace said grill cloth and maintain the "Bang & Olufsen" logo on front. Turns out one woofer and the mid were still in it. I can certainly see why the mid was there, are those things epoxied in or what? So this is my first look at the front of the baffle and I noticed two interesting things.

1. The tweeter opening expands into a very nicely contoured horn that looks like a small trumpet. Try that with a piece of plywood or MDF.

2. The mid has its own enclosure, which seems to be a common practice when cone type drivers are used. When I was first assessing my 140's for repair needs, I pulled the back from the mid enclosure to check the surround. Turned out to be rubber that was in good condition (thankfully). I noticed two sets of 4 holes (approx. 5/8" dia.) each on either side of the driver, but couldn't see through them. "Why bother with the holes just to block them off?" thinks I. Turns out the holes, one set slightly below center, the other set slightly above, are covered by a thin piece of coarse felt. A vented enclosure for the mid. I may be showing my newbness here, but I've never seen or heard of such.

This B&O stuff is really quite interesting. I may have to get some more.

 

["ItsTooLoud"]

COOL! As I will probably never remove the grillcloth from mine, I would never have known about the 'flare' for the tweeter. Also, I had suspected that the mid enclosure was vented, but now I know! Our parts seller let me know that he was afraid to try to remove the mid from it's baffle, so he CUT the entire mid enclosure from the rest of the speaker and sent it like that. I grin whenever I think about that. I think I may mount it in the center channel cabinet as is, since it was so elaborately designed. Too bad I didn't get the tweeter flare as well. I may have to try to replicate that. Well, my delivery date was pushed to Jan 4, so I'm still waiting.

I can't make my mind up about my RL's. Some material sounds wonderful, and some just sounds so dull. I really hope moving them a little and re-capping does the trick. They seem to be missing the 'magic' I wish they had.

 

[Mazeppa]

COOL! As I will probably never remove the grillcloth from mine, I would never have known about the 'flare' for the tweeter. Also, I had suspected that the mid enclosure was vented, but now I know! Our parts seller let me know that he was afraid to try to remove the mid from it's baffle, so he CUT the entire mid enclosure from the rest of the speaker and sent it like that. I grin whenever I think about that. I think I may mount it in the center channel cabinet as is, since it was so elaborately designed. Too bad I didn't get the tweeter flare as well. I may have to try to replicate that. Well, my delivery date was pushed to Jan 4, so I'm still waiting.

Sounds like he did you a favor, now you don't have to replicate the correct volume and porting. I may be able to fix you up with the tweeter flare, but let me see if/how grill cloth replacement goes.

I can't make my mind up about my RL's. Some material sounds wonderful, and some just sounds so dull. I really hope moving them a little and re-capping does the trick. They seem to be missing the 'magic' I wish they had.

I'm hip (as noted in post #60), but I'm reserving final judgement until I get them recapped.

 

["ItsTooLoud"]

Found some magic. I tried bypassing the digital processing in my preamp (not sure what gets bypassed by the 'bypass' command), and the realism and 3D imaging of the remastered 'Give a Little' by Supertramp was far superior than what I've heard from that track ever before. The difference between normal and 'byp' is much greater than what I heard with the old speakers.

 

["ItsTooLoud"]

The entire CD was a revelation. I babbled about it like a gibbon on meth when my wife got home about 30min later. She smiled at my enthusiasm, but even she was wide-eyed when Dreamer went from the intro to full-band. Wow, these are GREAT speakers. I could've listened to them all night. I have a stack of CD's I want to go back through again. Good thing she's going back to work Mon, cause I need some serious listening time. Next is a re-cap (once Mazeppa gives his report), and some vastly improved cables and wires a-la the DIY section.

So, Mazeppa, you're about done with your re-cap, right? RIGHT???

 

[Mazeppa]

Found some magic. I tried bypassing the digital processing in my preamp (not sure what gets bypassed by the 'bypass' command), and the realism and 3D imaging of the remastered 'Give a Little' by Supertramp was far superior than what I've heard from that track ever before.

You're ruined now. Not so dry now, eh? Well known to many, but only recently accepted by me are a couple of general principles that I believe impact on your recent finding about sound quality.
For your consideration:
1. The shorter & simpler the signal path between source and speaker the better.
2. (1a. really) The less "digitizing" inflicted on your music the better.

The Great Karnak sees two systems in your future; analog stereo for music, digital HT for watching movies.

The difference between normal and 'byp' is much greater than what I heard with the old speakers.

It would seem your 140's are an upgrade over what they replaced.

 

[Mazeppa]

The entire CD was a revelation. I babbled about it like a gibbon on meth when my wife got home about 30min later. She smiled at my enthusiasm, but even she was wide-eyed when Dreamer went from the intro to full-band. Wow, these are GREAT speakers. I could've listened to them all night. I have a stack of CD's I want to go back through again. Good thing she's going back to work Mon, cause I need some serious listening time. Next is a re-cap (once Mazeppa gives his report), and some vastly improved cables and wires a-la the DIY section.

I suggest you run, don't walk, to: http://www.audiokarma.org/forums/showthread.php?t=61442
A great how to that yields excellent interconnects. All I use. Should be given top priority, I'd say.

So, Mazeppa, you're about done with your re-cap, right? RIGHT???

Sadly no, but just about the time I start getting lazy on these 140's you shoot me w/a dose of "git 'er dun". Should be getting to it on Tuesday. I'm finishing up refoaming the woofers and a general rehab on a pair of speakers for my boss's boss. Those of you so inclined please join me in a moment of prayer for a good result.






Amen. Thank You.

 

["ItsTooLoud"]

You're ruined now.

I did narrowly miss out on a B&O tangential TT on cl the other day...

Re-foam for the boss's boss??? Boy, no pressure there at all.

 

[Mazeppa]

I did narrowly miss out on a B&O tangential TT on cl the other day...

Tangential? Is that where the "T" in T-Arm type turntable comes from? I've never even seen one. Sounds like an interesting device.

Re-foam for the boss's boss??? Boy, no pressure there at all.

Actually I made it sound hairier than it is. He's a very cool guy, and had already been advised by a third party that knows something about speakers that he may have done difficult if not impossible to repair damage by playing them sans surrounds. He bought them new in the early 90's, and pulled them out of retirement (unused for 4-5 yr.s) on that sentimental thing we older guys get into. So the risk/reward aspect is in my favor. BTW, the 1rst pair is done and turned out quite well.

 

[Mazeppa]

RL-140 Recap Report

Got the first one done yesterday. Actually went much easier than I thought it would. Was able to fit all the new cap.s on the PCB, two of the bypass cap.s were mounted on the bottom of the PCB.
The speaker wire terminal replacement went as easily as I thought it would. The binding post item from PartsExpress has the same center to center dimensions for the mounting holes and the spade connections as the factory terminal. Though the factory unit has 1/8" spades compared to 1/4" for the replacement, the slots in the enclosure are a little over 1/4" wide. Except for the need to drill clearance holes for the solder lugs on the replacements, it have been a straight swap.

Pictures and notes to follow, Friday or Saturday I'm guessing.

So, how did it all work out? I've recapped some 4 pair of vintage speakers with varying degrees of success, always to the good. Most notable in the treble, then midrange with little or no discernible effect on the bass.

The amount of SQ improvement from this recap far exceeds anything in my experience thus far. Perhaps most surprising is an easily noticeable improvement in bass performance, I suspect it may be in the upper bass/lower midrange boundary region. The treble and midrange both just really took off. I'm not good at articulating sound analysis, but I will say this.....

......I had the freshly recapped speaker hooked up solo (system in mono) for a little break in time on my main system after a test run in the garage. It wasn't long before I noticed my foot was tapping, I got to grinning and wanting to sing along. Next thing you know, the CD is half over, the phone rings, and the interruption pissed me off! 1 speaker in mono and I was having a big ol' time!

Ok, ok so maybe we've got the psycho-acoustic "It's better because I want it to be better." trip going here. Well, that was yesterday. This morning I hooked up my OEM capped speaker and did the A/B thing (still in mono). Played the same passages of music in each speaker. Yep, the recapped one is much better. Tried listening to one then the other for a while trying to keep the brain in neutral. Couldn't do it, I had to make myself listen to the OEMer, the recapped one made me want to just stay there for a while. There really is no comparison.

That being said, be advised that the fundamental character ("voicing" I think is the audio term) of the speakers have not been changed, but performance has been improved.

So, if you have RL-140's with the OEM cap.s in them, please get some good ones in there and prepare to be delighted. Don't forget they really get up and go with sufficient juice, my amp is rated 125W into 8 ohms and runs them very nicely.

My thanks to all in this and other forums for sharing the know how that I lack, and the encouragement to embark on these projects. Truly, my electronics goes barely further than the ability to solder/desolder.

 

["ItsTooLoud"]

SWEET!!!

I was hoping you would notice a sustantial difference, so I'm so glad you did (for you AND for me, obviously). I've noticed deficiencies in the areas you mentioned (lack of lows suprised me more than it bothered me since I have a big bad sub), and I'm constantly fiddling with the treble ('0' or '1'). I'll be making good use of the parts list you provided within the next month or two, hopefully. So how long does it take, start to finish? I'm guessing that the other speaker will be done by Fri or Sat? So will these be replacing your mains in your main system???

I recieved the RL parts a few days ago, and they were really well packed. That's a HUGE magnet for a tweeter! The dome feels like rubber. Treated fabric, maybe? The mid was indeed sent in it's enclosure, which is kinda funny. I'm glad to have it, though. Now I need to figure out what the port is tuned to, so I can design a proper vent for the center I have in mind. With no thiel smalls I may have to do a sealed center.

 

[Mazeppa]

SWEET!!!

I was hoping you would notice a sustantial difference, so I'm so glad you did (for you AND for me, obviously). I've noticed deficiencies in the areas you mentioned (lack of lows suprised me more than it bothered me since I have a big bad sub), and I'm constantly fiddling with the treble ('0' or '1'). I'll be making good use of the parts list you provided within the next month or two, hopefully. So how long does it take, start to finish? I'm guessing that the other speaker will be done by Fri or Sat? So will these be replacing your mains in your main system???

Mine are on the stands with the woofers down and bass performance is substantial, very satisfying. Just for grins, you might try pulling yours off the wall and give them a go down low. Spec.s state the bottom of their range is 40Hz so they won't get seismic like your sub but I think they are more than adequate for music.

About 3 hours for the first one. The second one was done about 1 1/2 hours after I posted the above this morning. I've listened to a couple of cd's with no distractions and I'm loving what they bring.

With the recap, the RL's have gone from "I'm not too sure about these things" to competing with my Quartets for duty in the main system. I'll have to do another round of comparisons as I worked a new amp into the rotation during the recap work that I haven't hooked the Quartets up to yet.

I recieved the RL parts a few days ago, and they were really well packed. That's a HUGE magnet for a tweeter! The dome feels like rubber. Treated fabric, maybe? The mid was indeed sent in it's enclosure, which is kinda funny. I'm glad to have it, though. Now I need to figure out what the port is tuned to, so I can design a proper vent for the center I have in mind. With no thiel smalls I may have to do a sealed center.

Tweeter dome is a treated fabric, possibly silk. That center project is going to be very interesting. You might learn enough from that to design your own next time. Now that would be impressive.

As I'm typing, I can hear "A Salty Dog" by Procol Harum playing from the other end of the house and it reminded of what a a jammin' live band at a dance club sounds like when you get of your car in the parking lot.

Wow, think I'll pay the cover and get in where the action is.

 

[Mazeppa]

RL-140 Recap pic.s and notes.

Ahead of schedule, even. Industrial strength hot glue gun is your friend for this kind of project. I've really appreciated this kind of help from others in the past, so here's my chance to pitch in.

http://s713.photobucket.com/albums/...Recap/?action=view&current=RL-140Recap008.jpg

 

["ItsTooLoud"]

Thanks for the pics!!! What is a bypass cap? btw, the binding posts look swell. I'm certain to do the exact same thing.

Wow, I'm envious. Darn household projects...

 

[Mazeppa]

What is a bypass cap?

Capacitors of 1%-2% of the value of the primary capacitor that are mounted in parallel to its primary. They are constructed of materials that are of superior audio characteristics, but would be prohibitively expensive if used for the full value required. Word is that this configuration exhibits a disproportionately large share of the bypass cap's superior characteristics.

I'm just going on what I've read many times and this is the first time I've tried them in a speaker x-over. Could be the reason this job was more successful than previous ones? Hard to say w/out more trials, with and without bypass cap.s in various applications, and as big a hassle it is to get into these RL's, that'll come later in other speakers.

Check the parts list for specifics as to types, then google is your friend to learn more about them.

 

[dv1jtl]

i have a pair of BO RL 140.. DNT KNOW ANYTHING ABOUT IT .. WANT TO SELL IT ANY IDEA FOR HOW MUCH I CAN SELL THIS.. GOOD CONDITION OUTSIDE. SOUNDS GOOD BUT I GUESS THE WOOFER NEED TO BE FIX..THANKS,

 

[crankdoctor]

B&O RL 140 woofer specs, tsp

These are close, And more a 6 inch than 6 1/2. Verry loose susp. Not refoamed.

Fs 36
Qes 0.4649
Qms 1.984
Qts 0.3713
re 12.1140 ohms
le 1.1098 mh
vas 75.8667 liter
bl 8.50
cms 1605. um/n
mms 12.0061 g
sens 91 db/1w 1m
rms 1.3797

If anybody has a new reconed speaker i would like to know the specs!
Hope this helps for a possible upgrade driver.

 

["ItsTooLoud"]

crankdoctor - just to make sure, are those tsp for the original woofer or the replacement?

 

[The SGD]

hey there 'itstooloud'

while quite shocked you paid that much for a pair of redlines that needed work (honestly, in the uk the price/pair is MAX about 40GBP (about 70bucks) and that includes shipping). my father and I go through quite a few pairs each summer, refoaming, refurbishing and then reselling for $$$, so have nearly tested the whole range.

if you can find a pair, there were some of the smaller ones that came with a ABR instead of the port. these seriously kick ass!! honestly the bass is the sort you feel. they are perfect for home cinema and i was considering doing just that till i found how difficult it was to get the wall mounts.

you can tell if they have the ABR because the foam has almost certainly rotted and the description will mention a rattling sound, also it is a big ole rectangular job and you should be able to feel the hole where it should be through the cloth. because of the rattling they are therefore often the cheapest 2nd hand ones you can get and really worth the weekend setting them right!


also of note, on the 2nd hand market the dedicated stands and wallmounts (especially the wallmounts) are worth more than the speakers themselves, so dont bin them!

 

["ItsTooLoud"]

Hey there The SGD!

I don't live in Europe, and so I don't come across B&O equipment very often. The price I paid was normal for NA, although I've already made back $115 selling equipment that came with them, so, I guess I have $165 in them at this point (including the $50 I spent on surrounds). If I sell the last of that stuff then I'll have about -$15 in them. That's about $85 cheaper than what you normally pay, but I wouldn't let it bother me if I were you.

The floor stands come up for sale often enough. I've seen three for sale since I've bought my RLs (with stands). I definitely wasn't planning on binning the stands!

So I'm assuming that a port is more efficient than a passive radiator, though a pr doesn't allow the woofers to 'unload' under the tuning frequency. Is that what you've found?

Are there any other tweaks that you and your dad tend to do to them after you pick them up?