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Old 5th November 2012, 09:47 AM   #21
Prj57 is offline Prj57  Bulgaria
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Join Date: Nov 2012
Location: Sofia
@ Duanebrow - I think the Lab 12 we ordered is a 6 ohm version! I was looking at the specs and think that it will be fine with a 4 ohm plate amp @ 300 W. Driver's Re is 4 point something which should be fine with the amp. Or am I missing something?

I didn't see a 4 ohm version of this driver. Also, the company that offers the driver here provides the 6 ohm version. We ordered one new from E-bay (few bucks saved) I was checking out the manufacturer's website but did not see a 4 ohm version (maybe was over-excited)

@Djim - thanks for the clarification on the bracing. I was not sure if I should extend the brace toward the front baffle. I will modify it as you suggest. I like the flaring on the port, but it will greatly complicate the construction and assembly of the box. I have basic power tools and I am taking the MDF to be cut by a third party on a table saw (less fiddling with sand-paper on the edges on my part) I've heard about kerffing or something, a procedure that makes the panel bend without breaking the surface. It looks really nice, but a little bit advanced for my carpenter skills.

On my design, I kept the corners as well as the double front baffle which aims to also reinforce and hold the port wall better. I will most probably get rid of the 45s in the front cause, as Duanebrow pointed out, they actually don't do much other than take space. I agree with this after giving it some more thought.
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Old 5th November 2012, 06:01 PM   #22
Djim is offline Djim  Netherlands
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Join Date: Dec 2009
Location: 'Ollanda
Hi Prj57,

You always can simplify the construction for the flare by making it 45 degrees.
Afterwards you always can use sandpaper to round it a little, MDF is easy to work on.

Click the image to open in full size.
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Old 6th November 2012, 12:57 PM   #23
Prj57 is offline Prj57  Bulgaria
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Join Date: Nov 2012
Location: Sofia
Djim, i really like the 45 flare! It didn't cross my mind earlier...

I am currently trying to model the new box for the Lab 12 so that I can focus on my car audio sub (remember, this is a double sub thread ) However, I won't be able to focus on that before I finish the Lab 12 box with all the bells and whistles I'm stuck at work for lack of interest or spare change in the nuclear energy industry - to put it simply and don't have much spare time in the afternoons. I was up til 2 am this morning trying to figure out the braces on the new box (45 flare vent makes the inner box a-symmetrical). I am stuck on whether to use a single support with 2 openings or a double support with 3 openings.

Hopefully I will have something to show you guys by this evening. In the mean time, I am thinking on ways to improve my current car audio box ( by making another, better one) Problem is, space is an issue, but more on that later!

P.S. My car sub is currently an Audiobahn AW 101 T in a relatively small vented box! I also have a slightly damaged ( 2 times repaired) Fusion Audio NV-SW 12 dual 2 ohm sitting in the garage. I want to make a better box for the Audiobahn as a 10" sub in my Land Rover is enough, plus its a daily driver and goes hunting / off-roading and the occasional baggage handling capabilities, so I remove the sub when needed!

Last edited by Prj57; 6th November 2012 at 01:27 PM.
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Old 7th November 2012, 06:12 PM   #24
Prj57 is offline Prj57  Bulgaria
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Join Date: Nov 2012
Location: Sofia
Update: I have been overburdened at work, loosing sleep badly and on top of that i have a blown speaker in the car and that's because I'm an idiot!

I know I am running 10cm speakers + 10" sub and I know that the 10s can't really match the sub and I know I needed at least 80Hz HPFs on the door speakers but... *&%# happens!

Anyway, I finished the Lab 12 box design, I haven't calculated the volume of all bracing though, but at least on design - I like the box! My friend was blown away, now all its left is for it to work I guesstimate the bracing will subtract a fair amount of volume!

Djim's idea about the 45 flare on the vent was VERY welcomed, for which I am VERY thankful. There are some minor touches to be done to the center cross section of the brace, I am wondering whether to make it 45 section all around in the center. Same 45s as the brace support. It will be like hexagonal pylon

I am reaching the conclusion that I will not be able to find filters that I need in the shops, therefore I will have to teach myself how to make them! Which is good, but I have only basic knowledge of capacitors, resistors, inductors and the like, plus my soldering skills are in dire need of refreshment There are components available, but don't really know what to look for in terms of brands or what "signs" of quality to look for or even what values! For the Lab 12 I figured that I need a 2nd order 25Hz HPF just so to tame the excursion in the 20 region, at least.... I think! There are 150 pages of reading material waiting for me on the subject, but I just can't find time for them

To clear my mind - I've been thinking about my Audiobahn 10" and.... I now understand the difficulty in getting good sound from limited space in messed up environment I've started calculating a new box and oh boy, its not easy! Working with limited space requirements is a pain...

I will be back with some calculations on the car sub later, but at least for now you can have a look at the Lab 12 box and tell me what you think.

P.S. I still can't decide how to mount the plate amp! I can make a section to the box or I can leave the box passive and make a separate (maybe attachable) box for the amp!
Attached Images
File Type: jpg Dimo's Lab 12 @ 28 Hz final 1.jpg (144.2 KB, 38 views)
File Type: jpg Dimo's Lab 12 @ 28 Hz final 2.jpg (147.0 KB, 36 views)
File Type: jpg Dimo's Lab 12 @ 28 Hz final 3.jpg (66.0 KB, 36 views)
File Type: jpg Dimo's Lab 12 @ 28 Hz final 4.jpg (164.6 KB, 34 views)
File Type: jpg Dimo's Lab 12 @ 28 Hz final 5.jpg (158.1 KB, 10 views)
File Type: jpg Dimo's Lab 12 @ 28 Hz final 6.jpg (72.7 KB, 9 views)
File Type: jpg Dimo's Lab 12 @ 28 Hz final 7.jpg (94.6 KB, 7 views)
File Type: jpg Dimo's Lab 12 @ 28 Hz final 8.jpg (93.9 KB, 7 views)
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Old 6th December 2012, 07:51 PM   #25
Prj57 is offline Prj57  Bulgaria
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Join Date: Nov 2012
Location: Sofia
It's been a while.....

Too much work before the Holidays, it's unbelievable!

The Lab 12 box has come a long way. This is the latest progress update, the box is expected to be fully operational and broken in for the New Years party

The speaker arrived - simply beautiful
The amp is here - now I need to get a 220V -> 110V transformer!!! Didn't realy have the time to check, but when it was ordered I missed the part where it said "Ītem origin - USA" which is cool, but we operate on 220V here

It took me 3 weeks to finally get someone here to cut MDF by customer dimensions AND with customer material!!! 4 companies turned me down, just because they wanted to sell me THEIR MDF which was at least 30% more expensive! In hard times like this, with austerity in Europe and all, I can't believe people are turnig down work! Basically 4 companies did not want my money to cut the parts to specs with my material! :O Love my country, but half the people need to go!

Anyway... in the last few days we got the braces cut out, the box is very well cut. Currently its just assembled to have a look at it, no glue - nothing, specs down to the mm I redid the box design, added a separate compartment for the amp, made it slightly larger to account for the volume of the bracing inside.

Box Volume ~103 liter
Tuning ~29 Hz
Driver - Eminence LAB 12
Amp - Bash 300 (silver one, with the switch phase - yeah I know.... not much I can do there)

All that is left is to cut the double front baffle circle for the driver. All the parts are separate - I am thinking of gluing the two front parts together and then cut the circle - seems to be the easiest way. MDF glue, 4x45mm screws (pilot holes before that) and we are thinking of paint - for better interior matching

Here are some pics of what has been done so far:
Attached Images
File Type: jpg 1.jpg (176.3 KB, 6 views)
File Type: jpg 2.jpg (76.8 KB, 7 views)
File Type: jpg 4.jpg (177.2 KB, 5 views)
File Type: jpg 5.jpg (202.8 KB, 6 views)
File Type: jpg 7.jpg (97.2 KB, 4 views)
File Type: jpg IMG_0898.jpg (749.3 KB, 14 views)
File Type: jpg IMG_0900.jpg (723.3 KB, 16 views)
File Type: jpg IMG_0902.jpg (735.4 KB, 13 views)
File Type: jpg IMG_0912.JPG (94.3 KB, 14 views)
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Old 7th December 2012, 12:25 AM   #26
Djim is offline Djim  Netherlands
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Join Date: Dec 2009
Location: 'Ollanda
Hi Prj57,

So far it is looking.... excellent!

(ps don't forget to fill the empty spaces before closing up everything...)
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