It will take some time.

At the moment I have new made samples which needs a little tweaking/modifying (details will follow later). Bit premature, but just to inform that there is progress.

I agree that the available surrounds from several suppliers doesn't satisfy at the moment. That triggered the making of...

Thank you Beobuddy!

Great to hear that we may soon have available a proper fitting foam surround for the Penta midrange drivers!

I'll be first in line to purchase a set when you bring this project to fruition.

Michael

If you have time and passion for restoration/upgrading, then you can go ahead with the Pentas.

They are my main speaker in my audio room, having Lab 3 and 8000s in other rooms, and the only thing that sounds limited compared to the new BeoLabs is the treble , that lacks some presence. This, and other things, can be easily overcome .

I did some serious restoration on mine, reconing the midrange drivers with rubber surrounds, soldering the internal wires with silver , replacing all caps, renovating the frets with new fabric, reversing the mid-treble enclosure on one of them to have proper symmetry, and the most recent upgrade was to pair them with a DSP that works like BeoLab 5's ABC, meaning the bass response is equalized to compensate for room acoustics.

I'm happy to tell you that the 100/120 Hz issue that Peter refered to is now gone, and that the Pentas, rated at 40 Hz at -8dB , are now producing 30 Hz at -6 dB without any problem! 

I also saw the Visaton midrange replacements on another british website recently, but never tried them.

Christophe wrote:

I'm happy to tell you that the 100/120 Hz issue that Peter refered to is now gone, and that the Pentas, rated at 40 Hz at -8dB , are now producing 30 Hz at -6 dB without any problem

Interesting, what DSP are you using?

Beobuddy wrote:

Michael Sean wrote:

So, based on my experience, there is a good chance that the Penta III's will not require new surrounds.  

 

My Penta III's from 1994 had foamrot. I changed them some years ago while the drivers were available.

Penta III's are sold with 2 different type of mids. The first version with a bit  "yellow/green" conus will have foamrot. The newer version with the grey coloured conus didn't have foamrot till today experiences. Time will tell.

Perfect fitted surrounds for the mids will be available in the near future 😕

Anyway to tell when the changeover was made? These are 128xxxxx serial which puts them around late 1997. Haven't gotten a photo yet so just curious.

Well. Interesting turn of events with this today.

Long and short of it is I went to look at the Pentas and ended up coming home with the damned Pentas AND a BS9000 Mk. I (I seem to attract those things like bees to honey, I don't get it. Yet I can't find a nice BS5E used to save my life!) for 1600.00, along with all the original packaging, the Mk I floorstand and a Beo4. It's not all a rosy picture though as the carriage on the BS9000 was having trouble moving when I plugged it in at the seller's house. Played a CD just fine, but really struggled to move to any position and it was NOT giving a "cleaning required" error. I really have no idea what I'm going to do with that 9k even if I get it working. I don't know what value they have being completely obsolete and impossible to repair. Still, I figured what the heck for an extra 600 bucks. Especially since the stand is probably worth 2 or 300 on its own and I already have a Mk 2 stand I could also sell.

Anyway, I digress. The pentas for all intents and purposes look brand new. He's been shuffling them around back and forth in his basement for the last year and a half or so so some things were not perfect, like the frets on one weren't clipping in very well and were loose (making the task of investigating the mid drivers on that one easy of course) although the frets fabric is fine. As best as I could tell all of the midrange drivers are in-tact. The surrounds on those midranges look grey to me, though there is a tinge of greenish color to that grey. They are not yellow/green by any stretch. They also didn't feel tacky. Now I just need to get them plugged in and see what surprises I find. These things in their boxes are even more of a pain to move around than the BL1s WITHOUT!.

Have them up and running now (sans displays, using PL cables I had connected to the 8000s), very balanced sounding speakers, but haven't had a chance to tweak yet. As of this moment they're on par with the 8000s so far. STRIKE THAT: with the Loudness control turned ON (which was also on with the 8000s but somehow got turned off) there is easily more bass extension here that the 8000s simply don't have. The highs are not as bad as I was worried they would be either (and one could argue that it's more "fair" to use the Loudness control with the Pentas since they have no ABL of their own which the later active 'Labs do). There's no contest with the BL1s here. The BL1 should never have been considered a replacement for this speaker in anything but utter beauty.

With much consternation I got the four outermost clips on the one loose fret to clip in. Nothing looks broken so I'm assuming it just takes patience and care to get ALL the clips to attach.

Nevertheless, I looked the speakers over and they're definitely in "new old stock" type condition. Meaning you can tell they haven't been knocked around over the years, but I suppose due to being in a basement and being removed for people to have a look or who knows what the metal parts on the cases definitely need to be polished up. They're not scratched, just fingerprints and such that over time have dulled the finish. So what is recommended to polish the metal? A couple of photos attached of the speakers in general and one not so good photo of the dulled finish... 

Guess I have to do these picture postings one at a time...

I think you have made a really nice purchase!

Probably you have the newer mk3 version. As I can see the "ribbed" tweeter and the greyish look of the conus.

If you could make a picture from the display while working, it will probably confirm this. The mk3 version with the green display were released with 2 different types. Not easy to notice, but side by side you can.

But the downside is the used parts  for the filters in the newer mk3 version. Small blue caps are used and these have to be changed at least. B&O made ihmo a mistake to use these low cost parts for the filters.

Thank you for the photos!

They look great!

As far polish, I used 3M Stainless Steel Cleaner and Polish on my Penta 1's. (I got them cleaned, I've just never gotten them running lol). It works great in that it cleaned years of grunge (especially on the top plate) and is completely non-abrasive. And it's made by 3M Brand who, in my opinion, makes the best of whatever they produce.

Also, I always use high quality microfiber cloths when cleaning any of my B&O items. Especially good when first received to remove the often years of grime. Those little fibers dig right in but are very soft on the goods.

Michael