Time is flying and I see it has been a long time since my last update.
Some have requested another feet design for the Basextension and I am in progress of designing a set of new stainless steel feet for the Basextension. They will be beautiful crafted, but not cheap to make. Another more futuristic design is also in the pipeline, so please have a look later or send me a mail to get an info when the new designs are ready.
Should any of you have a special request, either for your Carlsson or your Basextension please feel free to contact me.
Regarding the crossover for the OA-52; some owners are apparently playing the OA-52 standing free of the back wall and have complained about having too aggressive upper frequencies. I did not foresee that when designing the cross over, but In case you play the OA-52 standing free of the back wall, then the crossover needs to be modified or the tweeter will be too aggressive, after your hint, I tried it, and I must admit it makes a big difference.
By pulling the speaker out from the wall, the bass will become slightly more accurate, and since the tweeter has a build in waveguide, it will play well with 1 meter to the back wall, but the crossover needs to be adjusted.
If you know that you will be playing with your Carlsson standing free from the back wall, please contact us and some alterations has to be made to the crossover.
I have delivered the Basextension in different colors but also in “natural” MDF for customers to paint themselves together with their own OA-52 to get the tone of the colour right. Feel free to contact me if you have any special requests.
If you want your speakers and Basextension to be assembled and painted together to avoid any color differences or technical malfunctions, please contact me for an offer. I do not paint them my self, but I can ask the company I work with for an offer.
Regarding the OA-51, as I mentioned earlier, the design is well under way, the speaker is now in a more final part of the development where we try them in various different combinations of room and equipment. We do this to ensure the best compromise for the crossover. More different set-ups reveal the need for minor changes to improve the end result. It should not only play great in my listening room. Sadly you have to have a little more patience it will take a few more months before it is ready. Unfortunately the fine-tuning is not done over night; it takes many hours and many different kinds of music to get it right.
Further more have we designed a square front plate for the tweeter in style with the original tweeter for those of you does not want the round front plate on the original ring-radiator. If you use the original round front plate, the old screw holes will be visible on your speaker and they needs to be filled and painted to look good. Maybe some of you does not want to do that on an old original box, which I fully understand.
In the meantime I have enhanced my collection of OA-52s, because I sadly didn’t own an original one. But now I do and I’m very glad to do so. Besides the original OA-52 I have 2 sets UE versions, one that plays as a regular 2-way speaker and one with the Basextension. For the OA-51, I have the one pair I use to trim the crossover for the upcoming OA-51 UE kit. Unfortunately I don’t have an original pair of OA-51’s to compare with, so I just follow my own ideas and use the original OA-52 as a reference.
I have mounted all my OA-52’s on stands, even the old original ones. I don’t listen in far distance from the speaker and I don’t have an empty wall to play up against, as I think it’s required to make the old ones shine the best they can.
It is my personally taste – but actually I don’t find the OA-52’s very attractive standing on the floor. I think they look too small. As you can read on the project page, I also feel I look down on the artists when the speaker stands on the floor. If you raise the old one, the tweeter will be slightly more reduced, try it and see for you self.
And in regards to the OA-52 speaker stands I am currently working on the design and they will be ready during the summer.
Thank you for reading all this, and please stay tuned - I will get back with more information shortly.
Do you have any remarks or ideas, feel free to drop me a mail. I can be reached at
The summer is over and the first sets of upgrades are on the way to the new and hopefully happy owners.
I bought a second pair of OA-52. They were previously upgraded to an LE version, but which one is unclear. Well I only needed the boxes, so they were quickly stripped.
I now have 2 sets of OA-52, one black and one white.
I wanted to use the 2nd pair and original boxes with the original damping, to adjust damping, for you to make an upgrade with my UE kit much easier.
When placing the new secondary damping correct in the original boxes, then the difference to my first “all in” project is only marginal.
I helped on upgrading one of the true original OA-52 speakers, and I had a good chance to listening to them before we upgraded them. The foam on the woofer had been changed, otherwise 100% original – Nice to see!
The original was actually not bad, taking the age into account.
Should I briefly describe the differences from the original to the new UE-kit, it would be:
•The new kit is more 3-dimenional in the soundstage than the old one.
•My kit gives a much larger dept in the soundstage than the original.
•The precision in the instruments are better.
•It is easier to “place” the musicians in the soundstage.
•The details and the attack in the music is better with my UE-kit.
I have spent the summer getting the New Basextension ready. It consists of an 8” woofer in a vented box that fits great under the OA-52 boxes.
Remember my kit require the speaker to be placed on a stand some 430 mm above the floor.
The reason for that was described earlier.
The new basextension box is made by a Danish furniture maker, and the details are absolutely high class.