My another one vintage speakers - Beovox 5702

[Oldsansui441]

They do look beautiful indeed, great wood refinishing skills .

 

[Martynka]

In M70, the Seas woofers were made of plain paper. In 5702, Philips AD1056 were covered with some preparation. Careless and unsightly.

This brown color had a vintage feel but irritated my sense of aesthetics. That's why I bought it:

Visaton LTS-50. It should not only change colour but add stiffness and reduce unwanted vibrations. I'm very interested final effect.

I put one layer and it was not what I want

It was f.....g grey, but when start dry change colour to black... ufff. I applied the second layer bolder and I went sleep. This morning the effect surprised me positively.

Before:

and after LTS-50:

 

[A400]

Well there’s no doubt they look more uniform after, I can see why you’re pleased. I quite liked the look before though.

I happened to buy some Philips speakers recently with a similarly imperfect application of dope to the AD5060 mids which I’d never seen before. There is much to learn.

 

[Martynka]

Yes, vintage look was cool, but I hope what it's not only look, I hope that LTS-50 improve woofer sound.

 

[Martynka]

@A400 I look at your Philips and see that it looks the same as mine. This ensures that it is factory impregnation for increased stiffness. This means that the LTS-50 was the right choice.

 

[Martynka]

Ok, I tested bass. It's something incredible. It changed not only sound but woofers work too. I played "Two Feet - Go **** yourself" and bass was harder and stronger than before use LTS-50. Now bass "hit in point" if you know what I mean. It is not lazy, now sounds with precision.

Before aplied Visation, the woofers were shaking. They jumped front and back even though there were no low sounds. Now there is no uncontrolled jump. It seems the woofers are standing still. Even at very low impact they seem to stand still although the bass is stronger. I will try to edit a movie that shows it because I recorded the behavior before LTS.

 

[Oldsansui441]

Thanks for sharing your findings Martynka, l wasn't aware of that product. It certainly looks a lot better.

 

[Martynka]

A still wait for capacitors from UK, but I made new speaker wires.

but because in my Beolab 5000 I have two pin DIN connectors, I spent evening with inventing and soldering. Now I have banana connectors straight from amplifier.

changes can be undone and you won't any damages. Of course, the original Speaker s1, Central and Speakers 2 connectors work.

Yes, I know, strange things come to mind during quarantine...

 

[Martynka]

My covid19 free zone:

This is not to be funny, it is real. A place where you can play music, listen and forget all the **** around. I wish you all, places like these.


Marcin.

 

[Oldsansui441]

Thank you, yes it is especially good to have music as an escape ATM, nice setup of yours . When l get a chance l am going to setup my Beomaster 4400 and Beovox 5700's to audition properly together, you have inspired me, haha.

 

[Martynka]

4400.. ech.. I had dilemma Beolab 5000 & Beomaster 5000 or Beomaster4400. Visually I prefer my setup but musically... some say that BM4400 sounds better. My friend with 5700 bought 4400 and I hope that it be repaired before we will compare our speakers.

P.S. Tomorrow I will change filter and power capacitors in my 5000

 

[Oldsansui441]

Yes, your 5000 is more period correct & l also like the look. The 4400 is a great receiver but not as "boxy" looking like the early Beovox's so doesn't match quite as well visually. Will be an interesting comparison between your setup and your friends.

Let us know if the new caps make much improvement to your 5000 .

 

[Martynka]

After banana terminal mounted my Beolab sounds hearable better. It is not because . Inside Beolab 5000 all conections between power transistors, capacitors and PCB are done with 1,5mm2 but from PCB with Speaker selector switches to DIN conector you have only 0,5mm2. I soldered wires to capacitor out and I missed the 0,5mm2 wire connections.

Before, when I played powerfull it was heard like Beovox loose power, some fluctuation. Now I don't hear it.

 

[Oldsansui441]

Maybe the switches were letting it down more than the traces?

 

[Martynka]

.... Interesting about your friends 5700 version, mine are type 6229 if that helps?

There is no reference to the crossover version anywhere online that we both apparently have.

Yes,yes,yes.... I found scheme of our 5700 (6229) and 5702:

and one more time 5700 (6253) to campare:

 

[Martynka]

I compared sound before listening , I used Xsim and here are diagrams:

6253 :

and here 6229:

it not look good but then I inverted tweeter polarity :

for me now is better. I looked one more time on photo 6253 crossover:

and inside my Beovox:

In 6253 like on scheme midtones - wire ( blue ) is with hitones - wire ( white )

in 5702 and 6229 midtones - wire ( blue ) and woofer - wire ( black ) is with hitones + wire (violet). It is the same like than I invert polarity in Xsim.

On scheme from Bang Olufsen (6229) is wrong tweeter palority.


Bravo me !!!!

 

[Oldsansui441]

Thank you for that very valuable information, you did well to find that crossover schematic, l couldn't find it anywhere. So what l take from your findings is that our tweeters are in fact wired correctly from the factory, it's just that the schematic is incorrect?

You have me curious now as to which version was the first version of the 5700, the 6229 or the 6253. If l was to guess l would say the 6253 may be the first version since the 6229 version has the same crossover as your 5702's.

 

[Martynka]

I checked more photo with 6229 crossovers and all has inverted polarity like my. The same is KEF104aB with T27 tweeter.

What serial number do you have ?? I think earlier than 6253 and I know about something else...

 

[Martynka]

If you read this article from 1972 "Stereo review"

"The system impedance was between 6 and 25 ohms"

I think it was first version of 5700 and if you check impedance in Xsim you can see:

- in 6229

and in 6253

to

For me it mean that BeO changed crossover to decrease impedance peak but it decrease a little frequency response:

Red - 6229
Blue - 6253

but, if you check impedance diagram from other speakers this peak is nothing bad.

 

[Martynka]

Meanwhile, today I picked up this little beauties to Beolab 5000 - Mundorf MLytic AG Power Caps :

and I replaced all old power capacitors to new ones: