elephant:

actually 2,000 years old

another oops - and I had 7 years of "big latin" back in school

Anyway, it wasn't my language and I squeaked by with a "D"

 

tournedos:

Umm... I think you should've glued the fabric in the bottom of the grooves as well, as the bands aren't going to pull the fabric into them... they are purely for visual purposes, not for tightening anything. But that'll be a minor problem, I'm sure they'll still look great

I'll admit I wasn't excited to read this. The fabric only sits a few millimeters above the groove, I'm sure the straps would pull the cloth down to the surface, no?

Evan:

I'm sure the straps would pull the cloth down to the surface, no?

Yes

hemenex:

Evan:

I still find myself thinking about this!

Ok Mr. Evman, then there's no shipping, sorry...

Because then the way to do it is the Struer way - I'm absolutely sure we all want to have your promised birthplace factory story here to read

This alone would be worth givin' the BM4000 away (a functional one though; still leaving the recapping up to you for yet another story )

   Gunther

BTW: Did you measure the driver in question de-soldered? You mentioned they are different in the 2 speakers?

As I only have the SM for the previous PL60.2 with the ABR's and yours / Todd's are newer ones the crossovers are different

No need to give up a working 4000, I don't think I could accept that!

BTW, yes, the speakers are wildly different somehow internally. Check out my table a a few pages back. The results are all so weird!

Leslie:

Evan:

I'm sure the straps would pull the cloth down to the surface, no?

Yes

Ahhhh, that's relieving to hear!

I brought a BS 3000 and 2 BL 4000, as carry on bagage, from DK to Mex, back in 2001 or 2, my wife the BS 3000 in a back pack, and I the BL 4000s in a back pack. All brand new. In Mexico at that time these items was some DKR 50,000.00 (USD 10.000) and in DK I could buy the same for DKR 24.000,00. The dealer sold it for Export and I didn't have to pay the Danish 25% VAT. The dealer even made the 120 V convertion on BLs and BS..

So Evan bring a big back pack to Struer, remember they dont weigh carry on.

And I would like to know what you did or are doing with the diff. driver problems, so back to the bench

Evan:

Leslie:

Evan:

I'm sure the straps would pull the cloth down to the surface, no?

Yes

 

Ahhhh, that's relieving to hear!

I don't believe it will... to keep this educational, think of some force vectors and how much tension you are willing to put on the strap before it breaks - I'll bet it will bow up in the middle. The groove was glued originally, wasn't it?

But, no problem, just try it first... if it doesn't look good, you can probably still glue through the fabric and push it down with something while the glue dries. The strap will cover the area anyway.

Søren Mexico:

I brought a BS 3000 and 2 BL 4000, as carry on bagage, from DK to Mex, back in 2001 or 2, my wife the BS 3000 in a back pack, and I the BL 4000s in a back pack. All brand new. In Mexico at that time these items was some DKR 50,000.00 (USD 10.000) and in DK I could buy the same for DKR 24.000,00. The dealer sold it for Export and I didn't have to pay the Danish 25% VAT. The dealer even made the 120 V convertion on BLs and BS..

So Evan bring a big back pack to Struer, remember they dont weigh carry on.

And I would like to know what you did or are doing with the diff. driver problems, so back to the bench

I am so ready to do this! I already dug out my Swiss Army bag! 

First both speakers will be re-analyzed and I will update my table. Todd bought a resister so we could experiment with correcting impedances. I will post the findings. Hopefully Iwill be able to do some SPL/octave measurements and quantify the before and after.

tournedos:

Evan:

Leslie:

Evan:

I'm sure the straps would pull the cloth down to the surface, no?

Yes

 

Ahhhh, that's relieving to hear!

I don't believe it will... to keep this educational, think of some force vectors and how much tension you are willing to put on the strap before it breaks - I'll bet it will bow up in the middle. The groove was glued originally, wasn't it?

But, no problem, just try it first... if it doesn't look good, you can probably still glue through the fabric and push it down with something while the glue dries. The strap will cover the area anyway.

Yes, the originals were glued. We will try it first and will report back!

Evan:

First both speakers will be re-analyzed

Sorry if I repeat myself but is the mid driver really another number or does it just measure different when soldered in?

According to the original B&O specs the 8 Ohms impedance for the complete speaker measured on the leads is the correct one - strange that the "better" one has 4 Ohms only

Key point will be equal drivers on both speakers - I don't think you can compensate with a purely resistive thing in series...

If still in trouble - desolder the mid driver in both units and "swap" them electrically with long wires - will have the same result as changing the driver physically like Martin suggested - then you don't need to "break" them out. Play a mono tune and compare...

And while desoldered measure the resistance of both drivers without any leads to surrounding other parts spoiling the measure. You measure resistance instead of inductance anyway as long as you are using a standard DVM.

A picture of the "red, red, black, brown (or gold? silver?)" thingy would be helpful to decide what it is.

   Gunther

P.S. My older RL60 have both 5.4 Ohms in DC.

Ev, now you got me hooked on that...

I had a closer look at your crossover picture before modifying.

And I had another look at the Beovox service manual available on-site (look after Beovox4 manual).

Page 1-15 looks like the crossover of the RL60.2. That board has 5 caps, 3 coils (+ one external) and 2 resistors.

Yours seem to have 4 caps, 4 resistors and 3+1 coils. Strange - has it been modified before?

Also the order number of the 2 "woofer" and "mid" drivers are equal (?) so should be the same (?).

Do you have a picture of the printed side of the crossover? Are both crossovers equally equipped?

Gotta fix that thing...

Hi Gunther,

Sorry I haven't been able to fully respond to your questions, for the most part I've been posting from my mobile - I always leave out details when posting that way.

I can't fully remember if I measured all 4 woofers unconnected. Which is why I will be taking both speakers back to the work bench to get a new set of uniform readings. Will start that shortly here in a few minutes.

I have also done complete speaker measurements, which are unequal. The good speaker is 4ohms and the problem speaker is 8 ohms.

These crossovers have not been altered in anyway until I changed the caps. Yes, they have the exact same components in the xovers.

I'm hooked on this too, I want to solve this! You are right, the woofers are the determining factor. Give me a few minutes and I'll have an updated set of values for you.

I think it was yesterday I told Todd - "I think this is the most science ever applied to an RL60.2!"

tournedos:

Evan:

Leslie:

Evan:

I'm sure the straps would pull the cloth down to the surface, no?

Yes

 

Ahhhh, that's relieving to hear!

I don't believe it will... to keep this educational, think of some force vectors and how much tension you are willing to put on the strap before it breaks - I'll bet it will bow up in the middle. The groove was glued originally, wasn't it?

But, no problem, just try it first... if it doesn't look good, you can probably still glue through the fabric and push it down with something while the glue dries. The strap will cover the area anyway.

Keep us informed, we both are curious how it works out. But as said at the start of this thread I already mentioned to glue or use DS tape the strap grooves.

What kind of straps are you using Todd&Evan? Did you already had the original ones?

Okay Gunther, here they are. With the drivers disconnected, for sure!

Component	Factory Spec. (Ohms)	Good Speaker (Ohms)	Bad Speaker (Ohms)
Tweeter	6	4.6-4.7	4.6-4.7
Mid-Woofer	8	6.3-6.4	Open circuit
Woofer	8	6.2-6.4	5.9-6.2
Small Coil	?	0.8	0.8
Medium Coil	?	0.5	0.5-0.7
Large Coil	?	0.7	0.5-0.6
External Coil	?	1.1	1.1-1.2
6R8 5% > X0	6.8	6.8	6.8
15R 10% > X7	15	14.7	15.1-15.2
Resistor  | | | |	22	1.7	1.7
1R0 5%	1	1	1
Speaker (Total)	8	3.8	7.2-7.3

I knew it was the mid-woofer all along...

BTW I'll get the pic of the printed side of the xover for you.

 

Leslie:

Keep us informed, we both are curious how it works out. But as said at the start of this thread I already mentioned to glue or use DS tape the strap grooves.

Yes I remember. We should have listened. The original straps are broken and gone away. I was going to help Todd track down some reproduction straps. I remember there was a BeoWorld member who was able to supply them at some point.

Evan:

I remember there was a BeoWorld member who was able to supply them at some point.

Yes, here excellent quality! I have them!

Leslie:

Evan:

I remember there was a BeoWorld member who was able to supply them at some point.

Yes, here excellent quality! I have them!

Okay, great! Hey Todd, you see this? Get on it!!

Leslie:

Could that deck be any prettier?!?!  Well done, Leslie.  How does it sound?

Evan:

I knew it was the mid-woofer all along...

 

But you were getting some sound out of it before, right?

Rich:

But you were getting some sound out of it before, right?

Yes, and still do. It actually has a decent output for a woofer that measures open circuit..

Evan:

Rich:

But you were getting some sound out of it before, right?

Yes, and still do. It actually has a decent output for a woofer that measures open circuit..

Well, remember the impedence of a loudspeaker and each of its component drivers varies with the frequency of the input.  DC impedence isn't exactly indicative of what the driver will see throughout its frequency range.  Of course, one would expect the two drivers to measure the same. 

My semi-educated guess is you have a damaged voice coil. 

While I've never used Mark for this service, Meniscus Audio offers reconing service for damaged voice coils.

Image source:  http://sound.westhost.com/lr-passive.htm

Here you are Gunther, sorry it took so long, I was distracted by dinner!

The were several "changes" or slight redesigns to the 60.2 crossover during production. The cross you are flashing Evan looks like mine but if Mika come thru with a picture of his it will be a chunk of chip board with everything run in series (like an old uniphase cross) It was changed at least one more time with the RL6000 and it nothing close electronically to the RL60.

The Service manual as I recall had a couple typos and emissions which is why I usually dont order parts until I have had a look inside.

Your lucky if the driver is bad I have a spare. In fact I have a whole speaker munus the cabinet.

 

Rich:

Of course, one would expect the two drivers to measure the same. 

Exactly. For me to get equal performance I need drivers with equal electical properties.

If I had one driver rebuilt, would it still result in a unbalanced pair? Would Todd have to get both mid-woofers rebuilt to get the all-desired balance between the speakers?