First post: Questions regarding ALTEC 612 enclosure - DIY

GM · June 14th, 2013, 12:15 PM

1] Yes, ?window? bracing is excellent/quite popular for non-high aspect ratio cabs such as the 612. The main thing is to not make the cutouts any smaller than necessary and of course add back its bulk to maintain the design volume [net Vb] as it can be > the original bracing?s.

2] Don?t see why not.

GM

**Tralalalala** · June 16th, 2013, 02:51 PM

Hello,

OK - so I have bought myself two plates of (1220mm X 2240mm) birch 18mm ply

This is the last drawing plans I will post in this thread ( just deleted previous drawing plans so I don?t make any confusion...) - These new drawings are the ones I will use to FINALLY build my own 612 cabs.

Regarding the frame : I have done some calculations : Thanks to GM for telling me about this in his last post.
the frame inside this DIY cab should be almost the same in volume ( a bit less ) as the construction inside the original 612C cabinet. - I also have to thank Altec Best for giving the dimensions of the original frame !

All measurements are in mm.

The inside volume of this DIY cab has exactly the same dimensions as the original 612 C cabinet.

- tralalalala

**alancohen** · June 16th, 2013, 07:01 PM

I think that if you are going to rear mount the driver frame, proper form would dictate beveling the hole, kind of like a mini horn.

**Tralalalala** · June 28th, 2013, 08:11 AM

Thanks alancohen for your input.

I have some updates :

1. I have now finished the first front panel for my DIY Altec 612 cabs . It has been made with a bevel with a 45 degree angle.

I have taken into account that the bolt circle that is 15 inches on the 604E speakers will not interfere with the outer line of the bevel circle .

see picture and drawing attached for more info :

2. Since I now building these cabs with birch plywood instead of MDF I will not paint them since the wood itself is so nice, something that can not be said about MDF. I am planning on building a pair of front grilles for these speakers : I will build these grilles out of extra material I have from the standard birch plywood plates : the different layers in the plywood that I will build the front grill-frame out of will be visible when seeing the cabs from the side.

3. I?ve done some modifications on the drawings in my previous post . I wanted the wood structure to go all around the cabinet. So I needed to scale down the width of the cabs with 4 mm. See new cutoutplan from standard plates below :

4. I also have now NOT included the slot to fit for the front panel to the cabinet since I did not have enough building material . I barely managed to get this to work.... My front plate has to be fastened to the rest of the cabinet with lamello biscuits.

- tralalalala

**Altec Best** · June 28th, 2013, 08:29 AM

You aren't including the port are you saying on the front baffle ?

**Tralalalala** · June 28th, 2013, 09:39 AM

Originally Posted by Altec Best

You aren't including the port are you saying on the front baffle ?

NO- that is not what I am saying... probably a language barrier

- english is not my first language.

What I am trying to explain in my last part of my previous post is as follows:

PS: the slot would have been 18mm in width and 10 mm in depth. I did not have enough material to make front panels with my first thought dimensions : 630 x 731mm.

- - - Updated - - -

One more thing...

I?m planning on using a set of Audiophile SD damping feet for my speakers.

Todays Carlsson speaker (vintage swedish speaker designs: later used by BOSE) fanatics do swear to this type of damping design.

Any thoughts on this type of damping design for Altec 612 cabinets ?
What types of design do you use ?

- tralalalala

GM · June 28th, 2013, 10:48 AM

Depends on whether you have a suspended [floating] floor construction or not. If not, then ideally you want to mass load the speaker to the floor with a very heavy plant, stone or similar top velcro'd on, etc.. Otherwise you ideally need to know the floor's resonant structure to find the right durometer absorber, which I've no clue how to calculate.

Easiest IME to just use spikes or cones with quarter size [or real quarters/$0.25] floor protection 'pads', which create an impedance mis-match between the two 'oscillators' [point end down in this case].

BTW, will all these drawings be in a pdf or ? once complete?

GM

**endeeinn** · June 28th, 2013, 02:22 PM

Originally Posted by GM

Easiest IME to just use spikes or cones with quarter size [or real quarters/$0.25] floor protection 'pads', which create an impedance mis-match between the two 'oscillators' [point end down in this case].

GM

Are you proposing the floor protection pads for use on hardwood, tile and/or similar floors only or are carpeted floors over a sub-floor also included or should spikes on carpeted floors be used without the protection pad?
Thanks