Alpair 12 - Damped Air Coupler box design

[markaudio]

Hi Super-Panda,
Actually, I have 2 X 19 litre BR box designs. I'll do my best to open a new BR thread soon.

Thx
Mark.

[wolkenlos]

hello, I follow this threat and want to build this Damped Air Coupler Box Design with the alpair 12 driver.

your dimensions are:
940 x 256 x 370 (mm)

my problem is, that I have only 300mm (370mm) for the speaker. is it possible to increase the high to 1100 mm (940mm + 70mm)??? if is this possible - were is the middle for the driver position (180mm + 70mm??)

thank you very much for help - sorry for my realllllllly BAD english :-)

regards
wolkenlos

[markaudio]

Hello Wolkenlos,
Scott maybe best to answer your questions but from my understanding, the Pencil box dimensions are very important. If the size changes, it may not work properly. Also, the driver position is very important.

It maybe better to use bass reflex unless you can make the space in your room for the Pencil design.

Happy new year

Mark.

[wolkenlos]

thanks :-)

regards
wolkenlos

[Scottmoose]

Basically what Mark said. The dimensions are critical, particularly the length (height); any changes will throw the tuning out. If you don't have sufficient space, I'd go with the BR Mark has done.

[wolkenlos]

thx for support - I found a other solution and more place for the pensil 12. I like the linear design and this great looking alpair 12 driver

I put all information together and made a PDF file - maybe anyone other will use it (german language) - if you agree, I will post it also in the Hobby Hifi Forum (Germany).

Link to PDF: http://www.freifisch.com/pdf/alpair12.pdf


greets
wolkenlos

[markaudio]

Hi Wolkenlos,
Thanks for the update. Very interesting to see this PDF of the Alpair 12 Pencil design. Yes, please put on the Hobby Hi-Fi Forum in Germany. Many thanks for this help

Cheers
Mark.

[wolkenlos]

hi mark!

I have placed the PDF file to to german HIFI Forum. I updated the PDF and took a Sketchup Pic.
Link to German Forum:
http://www.hifi-forum.de/index.php?a...4&thread=18313

I have one more question about the Pensil12 - need the Alpair 12 driver a frequency separating filter to increase the performace?

greets
wolkenlos

[markaudio]

Hi Wolkenlos,
Many thanks for your help and for posting on the German forum. Your PDF is a nice presentation, well done! I've posted the link:

http://www.freifisch.com/pdf/alpair12.pdf

I have a suggestion that will help make the PDF more clear. The attached pic shows 2 methods for centring the screw holes. The top pic is the safer method using a drill bit, tap with a hammer to make a centring mark. The lower pic is the quick method using the drill but care must be taken not to touch the cone.

Most important, the 4-mm drill should only be used to make the mark for the holes. If the box maker goes all the way through the wood with the 4-mm drill, the hole will be too big for the screws. Once the centring marks have been made, change to a smaller 2.8-mm drill to go through the wood. This size drill is the correct fit for the screws that come with the driver.

Be glad if you could explain this on the PDF and on the German forum.

Many thanks

Mark.

[wolkenlos]

Hi Mark!

I will update the PDF today...
Need the Alpair 12 driver a frequency separating filter to increase the performace?

Greets
wolkenlos