L-shaped port for vented design

[runethechamp]

I am working on my own DIY project based on the Rauna Chaconne. I still have a pair of those sitting back in Norway at my parents' house, so I decided to build a pair myself instead of trying to bring those 80 lb monsters over here to the Bay Area.

My dad measured the vent for me today, and it turns out it has an L-shape to it. It goes in for a bit, then down about the same distance. Does anyone know if this serves a purpose at all, or is it just done to fit a longer tube in a relatively shallow cabinet?

[PeteMcK]

re:'is it just done to fit a longer tube in a relatively shallow cabinet' - althought this is acceptible for a ported box, the Chaconne appears to be some sort of transmission line, so the answer is no.
So if you want to copy them, you'll have to get the stuffing right as well as the dimensions...

Edit: there appear to be two versions, the earlier one being a concrete 2-way, the later an MDF MTM... both look to have a normal port...???
Interestingly, made by Bo Hansson, who I remember did a keyboard record based on 'Lord of the Rings' way back in the 70's (if it's the same guy)...

[PeteMcK]

pics & sales brochure for the original about 3/4 the way down this page, (how's your Swedish?):

http://www.minhembio.com/jcoboy
(looks like a normal port)

info on the new version here:
http://www.chaconne.nu/info.htm
(Looks like there's no port behing the opening, so could be a TL)

[runethechamp]

Thanks for the links. I think I've seen them before in my search for info on the Chaconne, and my Swedish isn't too bad since I am from Norway originally

If you want to be picky, there are actually 4 versions of the Chaconne. One from the early 80s that is an MTM construction (not sure if I've ever seen pictures of them). Two concrete versions that are both covered in one of your links: one upright one with a rectangular base, covered in the article in your link, and the one with the hexagonal base and slanted baffle that that guy has at his house. The last one is called the Chaconne IIa and is the new MTM construction with mdf/cement board sandwich construction.

I am pretty sure both the concrete versions were vented port designs, while at least the newer Chaconne IIa is a transmission line. The older Rauna models included a transmission line design called the Crescendo at the same time as the upright Chaconne version. They are very similar in looks, but the Crescendo has the woofer above the tweeter and the port for the t-line at the bottom of the cabinet.

I have already built one out of two new "Chaconne" here, based on the upright concrete version. My big surprise was that the vent had the L-shape, and I will have to see if I can make a slight mod to that myself. The original vent had a diameter of 6.7 cm, while mine has a diameter of 6.2 cm, so I don't need quite as much length as the original.

And yes, Bo is also a part of Opus 3 records, and is a very accomplished man in recordings. I might want to pick up some of the records he has made sometime soon.