PDA

View Full Version : Go Deeper



TheBassDr
08-29-2013, 07:15 PM
I have 2 10" Premier subwoofers w/ 350w RMS and i'm looking to improve the <50hz response. The Vb is 4.16 cubic feet and the port is a "T" shape, exiting in the center of the enclosure, a little odd to me and I have no clue what it is tuned to.
Possible solutions I have heard/thought of:
Build a differently tuned box
More power
"Beefier" speakers (Though these are plenty powerful for my set up)

So, what is/are the best solution(s)?

bradl79
08-29-2013, 07:18 PM
Thats what she... oh wait u r talking about subs

Slo_Ride
08-29-2013, 07:21 PM
Thats what she.

beat me to it

bbeljefe
08-29-2013, 07:27 PM
Put em in a transmission line. They'll go low.

garychoffmann
08-29-2013, 10:06 PM
Just work with what the lord blessed you with

Ahmed Johnson
08-29-2013, 10:31 PM
If you can't go deep, do it in the butt. That's what some of these other guys do when they come up short.

TheBassDr
08-29-2013, 10:42 PM
Put em in a transmission line. They'll go low.

I don't understand what you mean, I only know transmission line as coaxial cable and such.

bbeljefe
08-29-2013, 11:07 PM
I don't understand what you mean, I only know transmission line as coaxial cable and such.

A transmission line is a type of enclosure. Specifically, a quarter wave transmission line or, t-line. They're remarkably simple boxes to design but they take up a lot of space. The benefits are that they don't suffer from port noise like a ported box but they do reach low notes like no ported box can. A t-line will usually play a full octave below tuning, which is usually the Fs of the driver. So for a couple of tens with an Fs of 32 hz, in a t-line they would play well below anything you'll find in most music and do it efficiently enough to hear or feel it well.

Here are a couple t-lines I've built. One with a ten. (http://www.caraudio.com/forums/car-audio-build-logs-cars-trucks-suvs/587392-jbl-gto-10-%BC-wave-t-line.html)

And here's a website that explains transmission line theory pretty well. (http://www.quarter-wave.com/)

If you want to build one, I'll be happy to answer any questions you have. And if I don't know the answer, I'll make up a cool story that makes it seem like I do. ;-)

Buck
08-29-2013, 11:09 PM
May be your box tuning, is it a pre-fab? Where did you get your box?

TheBassDr
08-30-2013, 02:51 AM
A transmission line is a type of enclosure. Specifically, a quarter wave transmission line or, t-line. They're remarkably simple boxes to design but they take up a lot of space. The benefits are that they don't suffer from port noise like a ported box but they do reach low notes like no ported box can. A t-line will usually play a full octave below tuning, which is usually the Fs of the driver. So for a couple of tens with an Fs of 32 hz, in a t-line they would play well below anything you'll find in most music and do it efficiently enough to hear or feel it well.

Here are a couple t-lines I've built. One with a ten. (http://www.caraudio.com/forums/car-audio-build-logs-cars-trucks-suvs/587392-jbl-gto-10-%BC-wave-t-line.html)

And here's a website that explains transmission line theory pretty well. (http://www.quarter-wave.com/)

If you want to build one, I'll be happy to answer any questions you have. And if I don't know the answer, I'll make up a cool story that makes it seem like I do. ;-)

At any rate it looks like an interesting build and i'd like to give it a go just for experience sake. I'll get with you after I measure my trunk.

TheBassDr
08-30-2013, 02:53 AM
May be your box tuning, is it a pre-fab? Where did you get your box?

The box is tuned but i'm not sure what to, it was made by a local shop: Cartunes in Utah. I'm thinking it's a box problem primarily.

TheBassDr
08-30-2013, 02:58 AM
More power is helping a little bit with the lower end response due to bridging the amplifier though I blew a fuse (both the 30amp's actually). What are some advantages & disadvantages to different enclosures? e.g. open air, infinite baffle, bass reflex, bandpass, transmission line, etc...

bbeljefe
08-31-2013, 02:20 AM
With IB and t-line boxes, you need a sub with low compliance, as there is little to no acoustical suspension for the driver. The benefit is wider bandwidth with no port noise. Bass reflex allows for acoustical gain but can suffer from port noise and the danger of unloading below Fs and Fb. Bandpass allows for even more acoustical gain than bass reflex but they roll off steeper and have a narrow bandwidth. Bandpass boxes are great for getting loud at a certain frequency but aren't usually good for sound quality. Also, it's difficult to hear a woofer bottom out when it's inside a box that's inside a box, so when that happens, the results aren't often noticed until the smoke leaves the port(s). Sealed boxes provide excellent acoustical suspension and increased power handling for the driver and they provide tight, clean bass but they do not create any acoustical gain so they're not good for SPL.

TheBassDr
08-31-2013, 10:26 AM
With IB and t-line boxes, you need a sub with low compliance, as there is little to no acoustical suspension for the driver. The benefit is wider bandwidth with no port noise. Bass reflex allows for acoustical gain but can suffer from port noise and the danger of unloading below Fs and Fb. Bandpass allows for even more acoustical gain than bass reflex but they roll off steeper and have a narrow bandwidth. Bandpass boxes are great for getting loud at a certain frequency but aren't usually good for sound quality. Also, it's difficult to hear a woofer bottom out when it's inside a box that's inside a box, so when that happens, the results aren't often noticed until the smoke leaves the port(s). Sealed boxes provide excellent acoustical suspension and increased power handling for the driver and they provide tight, clean bass but they do not create any acoustical gain so they're not good for SPL.
Good stuff, thank you very much. I think the t-line will be a great choice for my setup and sound goals. I'm not sure of my subwoofer's Cms, but they seem loose to me (probably a horrible, horrible thing to base my build on but i'm not really concerned, I have two to blow through haha).

SubieSPL_Maniac
08-31-2013, 10:52 AM
its definitely the box. I've designed 3 of my own boxes and they are all tuned a little bit differently. the best way to find out what your box is tuned to is to burn a disc that plays different hz tones and listen for which one plays the loudest. Obviously keep the volume and everything else the same for all the tones.

TheBassDr
08-31-2013, 11:30 AM
I have a tone generator that I can run to the RCA inputs but I don't have an impedance tester so I can only guess. This is a really rough guess but I figure it's tuned within the 50-60hz range. That's a great tip; thank you.