Thanks  I´m glad that I can help. 🙂

The schematic shows all four bass drivers installed in series, which would mean they are 32ohm each???

Bulgarien wrote:

 

 Here are  how a 20 years old  Penta amplifier look like inside!  Its nearly exploding!! The first sign are humming...😁

link

What about the amplifiers in the beolab 6000 - 8000.

Will they have the same problems after 15 - 20 years??

The schematic actually shows them in parallel.  I believe they are 8 Ohm units, but I'm not sure about that

I have a Beomaster 8000 that could be a good partner with my Beovox Penta's, but the BM8000 can only provide 150w if the total cumulatative load is 4 ohm, so I could use a pair of 8 ohm units in parallel to get 4 ohm, or possibly other combinations wired up in serial and parallel, the single tweeter would need to be 4 ohm though.

the Penta has 9 drivers, and I need to replace the 4 midrange anyway, and a few others, so I may as well change them all if I can use the external 3 way active crossover (Behringer CX3400)  that I bought ages ago for another project

http://www.behringer.com/EN/Products/CX3400.aspx

can anyone confirm that the bass drivers are 16 ohm, and wired up in parallel pairs to give 8 ohm ?

can anyone confirm that the 4 ohm midrange are wired up in serial pairs to give 8 ohm load ?

can anyone confirm that the tweeter is 8 ohm ?

I like a project like this, the Penta is really a fantastic speaker and these suggested improvements are really something you can hear.

I have a suggestion to take the upgrading even further. Coating the cones of the speakers will have a good effect on the sound. Also the individual speaker will perform a wider frequency response, leading to a total of a good frequency response for the Penta.

The coating I am using - see the picture here.

/Frede

Hi, I've just acquired a pair of Pentavox and, as expected, the midrange drivers are rotten. 

Looking at this thread, can someone please tell me the reference /specs of the midrange drivers, old & new? I'm trying to find a replacement for those, having no B&O dealer around. If not, could Peter Pan please take a picture of the midrange drivers, as zooming on the previous pics isn't that great?

Thanks in advance!

As far as I know, the Thiele parameters for the midrangedrivers are not known (except to B&O). So finding replacements is not easy. I will post a picture of mine later on.

I would suggest to replace the rotten foamsurrounds with new ones. It is very easy to do yourself, and it is cheap. I did several Penta's myself, and all functioned fine after the repair. I used to replace the rotten surrounds with new foam surrounds, but recently I found a supplier which can also deliver rubber surrounds. I did one pair of Penta's with the rubber surrounds and compared them directly with a set of Penta's using new foam surrounds. I could not hear any difference, but the rubber surrounds will almost last you a lifetime.

Here you can order the rubber surrounds:

Hi and thanks for the info,

I checked the website selling the replacement rubber surrounds, someone can do it for me, my main concern was whether the new drivers would bring any audible improvement, looks like not..

In that case indeed, it will be much cheaper to replace only the surrounds!😁