Audiobahn 34 Inch Subwoofer - Anyone ever build a box for one?

tomtomjr

Member
2008-02-15 7:18 pm
I am getting closer to finally putting my Audiobahn 34 Inch subwoofer into a car. It is a DVC, and 2 ohms per coil. I have a US Amps VLX-400 to run for power. I am currently looking for a small donor car to put it in. Figure I will make the back half of the car the enclosure. Thinking of a Honda 2dr Hatchback or turning my 2000 VW Beatle into the donor. Just curious if anyone on here has had any experience with putting one in a car. If so, have you tried a vented box, or sealed? A lot of work in building the box is required, so I figured I better get it right the first time.
 

tomtomjr

Member
2008-02-15 7:18 pm
I am guessing 10-15 for sealed. I have approx 10 cubes on a 32" Clarion for my shop speaker. Sounds great. But the Audiobahn requires 5000W per coil, and more airspace. So I would say somewhere 10 to 15 cubic feet. Here is a pic of the speaker. The small blue thing is a CD, and the small sub is a 10-inch RF. It is a monster sub, and very difficult to move around. I took the sub out of the crate to weigh it, and it was 211 LBS. The box will for sure have to have lots of bracing. I did not get a manual for the sub, and the specs on the internet so far are not much.
0504070103.jpg
 

jol50

Member
2007-11-08 2:14 am
Wow, impressive photo there! Certainly bracing will be a challenge with that. I wonder if you could make the box some other way, I mean that is something where wood might not be the best for but other materials have their issues as well. That would make the biggest sonotube ever:cool: If I did it right a 36" tube would be 2.122' long plus driver volume for 15 cubes. Providing you could fit that tube in a car and wanted to.
 

tomtomjr

Member
2008-02-15 7:18 pm
I am sure it will take some steel bracing. Don't want to hit the brakes and it fly out of the box and decapitate me. That would suck. New, they were something like $5k. I bought it from an audio shop that was using it as a coffee table. They had a piece of glass over it, and that was the table top, with the speaker as the base. Since it was used (as a coffee table) , I got a deal on it. I have had it for about 2 years sitting in the crate in my shop. Just been wanting to put it to use.
 
goodlord thats a monster !

how big is the coil on that beast? and the width of the spider?

that sub has a surface area of around 907.46 sqin, thats the equivalent of 5.138 fifteen inch subs.

theoretically if youd want to hit around 40-45 hz, id go with 17.98 cuft...with 251.75 sqin of port area...around 18-22 inches long.

only problem i see is that since the surface area is so large , your gonna need extra room for the wave to propagate and develop...

you might want to tilt the mounting angle around 45-30 degrees and load it.

look into PA boxes with an echo chamber.
 

tomtomjr

Member
2008-02-15 7:18 pm
The coil is 5" if I remember. Model is AWT-34. Measures 36" across. It is crated, and difficult to move, so I can't get you the specs on the spider. I would like to mount the sub vertical. Thinking I might only be able to do so firing backwards because of the wave. I was hoping someone on here had one, or played with one. I have seen 3 pics of them in cars, and the rest of the pics are of them as coffee tables, or in plexiglass boxes in displays.
 
Thiele/Small parameters for AWT-34X:

Fs 13.6Hz
Qts 0.968
Qes 1
Qms 11.65
Vas 743 Liters (~26 cu ft)
Re 1.95 ohms
Le 1.15mH
Xmax +/- 30mm
Pmax 5000 watts

Those parameters don’t suggest happiness in a ported box.

The manual suggests 18-22 cu ft.

In 18 cu ft sealed, Qtc would be around 1.5 with Fc around 20Hz before considering the car's influence.

Is the surround pleated foam?
 

tomtomjr

Member
2008-02-15 7:18 pm
The foam is accordian edge, not the foam. Looks like the early 18" Cerwin Vega type surround. It is close to the same style as what is on my Clarion 32" subs too. The surround is made of a fabric, not foam... Here are some specs that I found on the internet. Unsure how accurate they are, but the thread said they are for the AWT-34... Thanks for all the help........
Here are the Thiele small parameters

Fs 13.6Hz
Qts 0.968
Qes 1
Qms 11.65
Vas 743 Liters
Re 1.95 ohms
Le 1.15mH
Xmax ?????
Pmax 5000 watts


Here are the calculator values:
Driver : Audiobahn AWT34X
Number of drivers : 1
Box type : Closed
Box size : 123.114 ft^3 Optimum volume


Relative
Freq Gain SPL
[Hz] [dB] [dB]
20.00 1.78 1.78
25.00 1.48 1.48
30.00 1.13 1.13
35.00 0.86 0.86
40.00 0.68 0.68
45.00 0.54 0.54
50.00 0.44 0.44
55.00 0.37 0.37
60.00 0.31 0.31
65.00 0.27 0.27
70.00 0.23 0.23
75.00 0.20 0.20
80.00 0.18 0.18
85.00 0.16 0.16
90.00 0.14 0.14
95.00 0.13 0.13
100.00 0.11 0.11



At 5.000 ft^3 sealed
Relative
Freq Gain SPL
[Hz] [dB] [dB]
20.00 -6.09 -6.09
25.00 -0.13 -0.13
30.00 5.32 5.32
35.00 8.00 8.00
40.00 7.09 7.09
45.00 5.57 5.57
50.00 4.38 4.38
55.00 3.53 3.53
60.00 2.90 2.90
65.00 2.43 2.43
70.00 2.06 2.06
75.00 1.77 1.77
80.00 1.55 1.55
85.00 1.36 1.36
90.00 1.20 1.20
95.00 1.07 1.07
100.00 0.96 0.96




At: 10.000 ft^3 sealed
Relative
Freq Gain SPL
[Hz] [dB] [dB]
20.00 0.27 0.27
25.00 5.08 5.08
30.00 5.60 5.60
35.00 4.45 4.45
40.00 3.42 3.42
45.00 2.68 2.68
50.00 2.14 2.14
55.00 1.75 1.75
60.00 1.46 1.46
65.00 1.24 1.24
70.00 1.06 1.06
75.00 0.92 0.92
80.00 0.81 0.81
85.00 0.71 0.71
90.00 0.63 0.63
95.00 0.57 0.57
100.00 0.51 0.51



At: 15.000 ft^3 sealed
Relative
Freq Gain SPL
[Hz] [dB] [dB]
20.00 2.58 2.58
25.00 4.71 4.71
30.00 4.00 4.00
35.00 3.05 3.05
40.00 2.35 2.35
45.00 1.85 1.85
50.00 1.49 1.49
55.00 1.23 1.23
60.00 1.03 1.03
65.00 0.87 0.87
70.00 0.75 0.75
75.00 0.65 0.65
80.00 0.57 0.57
85.00 0.51 0.51
90.00 0.45 0.45
95.00 0.40 0.40
100.00 0.36 0.36



At: 20.000 ft^3 sealed
Relative
Freq Gain SPL
[Hz] [dB] [dB]
20.00 3.18 3.18
25.00 3.96 3.96
30.00 3.15 3.15
35.00 2.39 2.39
40.00 1.85 1.85
45.00 1.46 1.46
50.00 1.18 1.18
55.00 0.98 0.98
60.00 0.82 0.82
65.00 0.70 0.70
70.00 0.60 0.60
75.00 0.52 0.52
80.00 0.46 0.46
85.00 0.41 0.41
90.00 0.36 0.36
95.00 0.32 0.32
100.00 0.29 0.29



At: 25.000 ft^3 sealed
Relative
Freq Gain SPL
[Hz] [dB] [dB]
20.00 3.21 3.21
25.00 3.41 3.41
30.00 2.65 2.65
35.00 2.01 2.01
40.00 1.55 1.55
45.00 1.23 1.23
50.00 1.00 1.00
55.00 0.83 0.83
60.00 0.69 0.69
65.00 0.59 0.59
70.00 0.51 0.51
75.00 0.44 0.44
80.00 0.39 0.39
85.00 0.35 0.35
90.00 0.31 0.31
95.00 0.28 0.28
100.00 0.25 0.25



All qtc values are above1.00, and above 2.00 for the 5 ft^3


Driver : Audiobahn AWT34X
Number of drivers : 1
Box type : Vented
Box size : 500.920 ft^3 optimum volume ported box. not recommended
Tuning frequency : 5.45 Hz
Vent : 1 vent(s)
-0.7 in length for each
4.0 in round


Relative
Freq Gain SPL
[Hz] [dB] [dB]
20.00 1.98 1.98
 
The surround is made of a fabric, not foam...

It was obvious in the picture that the edge is pleated, and I couldn't imagine it would be pleated foam...

The .pdf manual I have is for the AWT10/12/15/18/34X, and generically specifies a 2" foam surround. Given the low production/handmade nature of the 34" (it feels wrong to type '34" woofer'), they may all have pleated cloth surrounds. You know how literature can be incomplete or slightly wrong.

Just be aware that these specs could be off a bit if the models were updated during production.

I'd be happy to email the .pdf if my dial-up can handle the file size.
 
I remember an experiment driver I made a few years ago. It had a flat 3'X4.5' rectangular pneumatic driven diaphragm. It had an unreal 12" XMAX..... The diaphragm used a series of "lanyards" with bearings used in skateboards to allow for positive tracking through a rectangular tunnel that measured 3.5X5'. I might have some pics around somewhere.

Let’s just say that it wasn’t much to listen too but would make you sick to your stomach if you were in a small room with it. Too bad I could not legal to use it in a SPL comps back in the day......


I have always loved big subs......
Oh the memories!


BTW: a VLX400 is a good choice.
 

tomtomjr

Member
2008-02-15 7:18 pm
I remember the Hartley. They were 24". Sometimes they pop up on Ebay every now and then. They still bring a good price. I was outbid on them fairly quick several times. Still want one...

On the "Diaphragm speaker" , I would like some pics of that if you have some. Sounds neat. Kinda like the one that was built on Mythbusters that was run off of the driveshaft. Forget what size it was, but it was big, and did 160+db with 30hz or something like that... Put up some pics Jonny..........
 
not to hijack this thread but my original idea was to use a crank shaft but was cautioned that in theory would not work properly because a crank shaft speeds up and slows down depending on the position of the "rod" on the crank. It slows to 0 @ TCD speeds up until its maximum speed at 15 deg. then slows to 0 at again at 50 deg and reachs max speed again at 75 degrees........ was told the because of the speeding up and slowing down the wave it would produce would not be good.

I have tried all sorts of experimental BS......I wonder how many peeps around hooked 16 speakers directly to a 120 volt AC household outlet!!!!!

(BTW, it makes something like 15K-25K (cant remember) watts @ 4 ohms @ 60 HZ)
Im busy with the car.....speedweek is only 4 months away but promise I will look for the pics soon.