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View Full Version : 2 chambers, 2 ports, 1 sub PICS!!



soloXgt
02-02-2008, 03:02 AM
gettin it loaded sat or sunday. Had a guy at work design and build this for me. All opinions are welcome. From what I am told, one port is tuned to 30hz and the other to 45hz When everything is hooked up, I'll let u guys know how it sounds. O yea, it was finished in bedliner. Opinions welcome....

http://i23.photobucket.com/albums/b365/babyjoker143522/0131081456a.jpg

http://i23.photobucket.com/albums/b365/babyjoker143522/0131081612.jpg

http://i23.photobucket.com/albums/b365/babyjoker143522/0131081623.jpg

http://i23.photobucket.com/albums/b365/babyjoker143522/0131081805.jpg

http://i23.photobucket.com/albums/b365/babyjoker143522/0131081940.jpg

http://i23.photobucket.com/albums/b365/babyjoker143522/0131082219.jpg

SilverSquared
02-02-2008, 03:05 AM
2 difft tuned ports in 1 box?

James Bang
02-02-2008, 03:13 AM
it is very difficult to understand the design of that box.

revrider1
02-02-2008, 03:14 AM
**Confused**

Looks nice though

soloXgt
02-02-2008, 03:15 AM
here is what it does/meens....i guess

http://images.google.com/imgres?imgurl=http://www.diysubwoofers.org/images/site/ported-dc.gif&imgrefurl=http://www.diysubwoofers.org/prt/dual_chamber.htm&h=164&w=72&sz=2&hl=en&start=14&um=1&tbnid=nw7SSsLocsv8ZM:&tbnh=98&tbnw=43&prev=/images%3Fq%3Ddual%2Bchamber%2Bported%26um%3D1%26hl %3Den%26rlz%3D1T4TSHB_enUS243US243%26sa%3DN

bottlebaby
02-02-2008, 03:18 AM
looks sick hope it works as well as it looks

BrianChia
02-02-2008, 03:24 AM
I really like the simplicity of porting in that design. As complex as it looks that is probably the simplest way to design/tune a dual chamber reflex box. Beautiful work. :)

jake760
02-02-2008, 03:24 AM
So all 3 ports share the same dimensions and the difference in tuning is the result of different net volumes of the 2 chambers? Say a standard ported box for the sub needed 60sq" of port, would this box need 2 30sq" ports or 2 60sq"? Looks interesting!

soloXgt
02-02-2008, 03:27 AM
i guess this is the reasoning behind this, based on the 35hz design, the tuning will fall between 30hz and somewhere around 45hz...with a pretty flat response (in car) between them....at the loudness of a 45hz or so tune, thats the goal." i'll only be giving it 1000watts when i get it in until i get the new amp

Immacomputer
02-02-2008, 11:31 AM
i guess this is the reasoning behind this, based on the 35hz design, the tuning will fall between 30hz and somewhere around 45hz...with a pretty flat response (in car) between them....at the loudness of a 45hz or so tune, thats the goal." i'll only be giving it 1000watts when i get it in until i get the new amp

Yea, that's not what happens.

I have built two different enclosures just like this and the result was the same both times. There is no output benefit from the second tuning point. The upper tuning point really just creates a high pressure area behind the cone which limits excursion around the second tuning frequency. There won't be a significant increase in output there though.

The enclosure will mainly act like it is in an enclosure that has a volume equal to the smaller chamber and the larger chamber combined tuned to whatever frequency. The tuning frequency will come from the total port area on the outside and from the total volume of both chambers.

I hope it sounds nice as the construction looks pretty good.

chinxtaboi
03-26-2008, 04:57 PM
wow, i totally dont understand this design. two diff ports to cover more range of frequency? im lost.

vetkilr
03-26-2008, 05:01 PM
Yea, that's not what happens.

I have built two different enclosures just like this and the result was the same both times. There is no output benefit from the second tuning point. The upper tuning point really just creates a high pressure area behind the cone which limits excursion around the second tuning frequency. There won't be a significant increase in output there though.

The enclosure will mainly act like it is in an enclosure that has a volume equal to the smaller chamber and the larger chamber combined tuned to whatever frequency. The tuning frequency will come from the total port area on the outside and from the total volume of both chambers.

I hope it sounds nice as the construction looks pretty good.

An excursion limiting ported box:eek:

mjf
03-26-2008, 05:01 PM
multiple tunings dont work well in regular ported boxes.

abc boxes yes, 6th+ orders yes

soloXgt
03-26-2008, 05:03 PM
I don't understand it 100% either, but i like how it sounds.



Final install pics.....http://www.caraudio.com/forum/showthread.php?t=302362

audioarsonal
03-26-2008, 05:08 PM
Its an ABC box.But the port set up doesn't look to be in the proper location.
Shouldn't both both chambers be ported seperately with a common port connecting the two?
I kinda see it in the pictures???

blackbonnie
03-26-2008, 05:58 PM
it looks nice

BrianChia
03-26-2008, 06:02 PM
multiple tunings dont work well in regular ported boxes.

abc boxes yes, 6th+ orders yes

It is impossible to do multiple tunings in a regular ported box. If you had two different sized ports there would still only be one resonance. For each different tuning frequency, you would need a separte enclosure. This is a double chamber bass reflex, hence it has two different chambers and two different tunings.

jmanpc
03-26-2008, 06:03 PM
looks nice. it took some staring to understand the design, but i get it now

mdillon
03-27-2008, 12:18 AM
see this syle alot with bose subwoofers.

psychoacoustics
03-27-2008, 12:58 AM
lookin good!

seedubs1
03-27-2008, 02:02 AM
I'm a fan of abc boxes. If anyone wants to learn more, go to termpro. They have a sticky on abc boxes.

Hope you like it.

PV Audio
03-27-2008, 11:57 AM
An excursion limiting ported box:eek:A ported box by nature limits excursion; you have the least amount of cone travel at the tuning frequency.

PV Audio
03-27-2008, 11:59 AM
And besides looking good, there's no reason to build a DBR for car use.

soloXgt
06-12-2008, 02:58 AM
yyup

NissanKicker
06-12-2008, 03:38 AM
The memphis rep - Forgot his name - came up with that Idea. It's based off the BOSE system speakers.

.... Ever wonder how a single BOSE System 4" woofer sounds like a 12" sub. It's because they created way to expand the range of a speaker. ( ABC box is as close as you can get without breakin' patent laws ).

I was lookin' @ the guy build his version of the enclosure. It was like 5cuft. internal for (1) 12... 3.5cuft for the port tuned @ 48 and the ~1.5cuft for the port tune @ 32. Both chambers where connected with a port ( The difference between the 2 ports. Ex: If one port is 3x3x3 and the other is 8x8x8 - The connecting port is 5x5x5 - * I asked, he never explained * ).

I was like WHOA! at how it dominated EVERY note that was played. He then burped from 20hz to 80hz....
20 made my mirror, car beside it, fall out the windshield.... & about ~56/~68 had me almost impossible to move.

.... It's a great enclosure when it's done right....
* I would have to look @ the blueprints... But it looks decent to me.

PV Audio
06-12-2008, 01:00 PM
Bose subs are not double bass reflex. They're either folded horns or bandpass.