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View Full Version : Box design? And why?



kush-divinity
10-31-2008, 08:31 PM
Now, before we say sub up, port back in SUV, I want you to explain why it is the best, and how it performs with other enclosures.

Case in hand: Explorer, plenty of room, 2x 15 or 1x 18 SQ based sub.
I know sealed will provide fail proof SQ, but at a cost of output.
I love ported, but know that there are ideas out here that I have never tried before.

What design would provide the best performance when a balance of 75SQ/25SPL is desired?

I must have the extreme low end extension that a sealed box provides, and would like to have the bump in output of a ported. What design will grant me a fairly flat response, or one that is exaggerated in the very low end, while still reatining the higher bass notes up to 70hz? I am pretty handy in construction, so a radical design is not a problem.

I have saw plans involving a folded or "S" style port on this forum. How well does this work, as I realize that if I use a larger port, I get more output, but it must be longer to achieve the lower tuning frequency.



Also, does anyone know a ballpark number for resonant frequency in a 1994 4door Explorer? From my noobish tests using music and test notes----I see around 45hz as it? Am I close?

skmfkr
10-31-2008, 08:48 PM
S ports are just to make the port longer

IDSkoT
10-31-2008, 08:49 PM
Now, before we say sub up, port back in SUV, I want you to explain why it is the best, and how it performs with other enclosures.

Case in hand: Explorer, plenty of room, 2x 15 or 1x 18 SQ based sub.
I know sealed will provide fail proof SQ, but at a cost of output.
I love ported, but know that there are ideas out here that I have never tried before.

What design would provide the best performance when a balance of 75SQ/25SPL is desired?

I must have the extreme low end extension that a sealed box provides, and would like to have the bump in output of a ported. What design will grant me a fairly flat response, or one that is exaggerated in the very low end, while still reatining the higher bass notes up to 70hz? I am pretty handy in construction, so a radical design is not a problem.

I have saw plans involving a folded or "S" style port on this forum. How well does this work, as I realize that if I use a larger port, I get more output, but it must be longer to achieve the lower tuning frequency.



Also, does anyone know a ballpark number for resonant frequency in a 1994 4door Explorer? From my noobish tests using music and test notes----I see around 45hz as it? Am I close?


T-Line :fyi:

kush-divinity
10-31-2008, 09:01 PM
I is nub when you say t-line?

WTF is it? Everyone locally thinks it is the ****, but no one actually knows about it....

kush-divinity
10-31-2008, 09:26 PM
Guess no one here knows either?

Where is that immacomputer guy? He always has an intelligent answer on a box question...

rpfuror
10-31-2008, 09:57 PM
T-line, just like a bandpass, will be very specific to the type of subs (TS parameters) that you chose ..... just like any other box...

Subs up /port back will not always be the correct choice. I have have had really good response to subs back / port back in my jeep with some designs and subs up / port back with others.

If you design a box you just need to make sure you that you have the right amount of space away from any restriction (for a back port for example), but depending on you tuning to much space from the port may change the wavelength which will inhibit the propagation of the frequency that you are tying to tune to ultimately causing distortion.. this is where the resonance freq of where your comes into play... again it all depends on the drivers you choose to determine most of this.

IDSkoT
10-31-2008, 09:59 PM
T-line, just like a bandpass, will be very specific to the type of subs that you chose ..TS parameters... just like any other box...

Subs up /port back will not always be the correct choice. I have have had really good response to subs back / port back in my jeep with some designs and subs up / port back with others.

If you design a box you just need to make sure you that you have the right amount of space away from any restriction (for a back port for example), but depending on you tuning to much space from the port may change the wavelength and distort the propagation of the frequency that you are tying to tune to... this is where the resonance freq of where your comes into play... again it all depends on the drivers you choose to determine most of this.

Yeah. For a T-line, your sub more or less has to be made for a T-line (not really, but it's really picky).

kush-divinity
10-31-2008, 10:25 PM
So, maybe better to go with a large sq/in port ported box, or maybe sealed?

My choices are pretty limited to 2x 15 D3 Diamond OR 1x 18 Fi Q.

Max SPL isn't important, but wonderful, rich bass, with no peaks (except maybe below 35hz) is desired.

Rashaddd
10-31-2008, 10:50 PM
So, maybe better to go with a large sq/in port ported box, or maybe sealed?

My choices are pretty limited to 2x 15 D3 Diamond OR 1x 18 Fi Q.

Max SPL isn't important, but wonderful, rich bass, with no peaks (except maybe below 35hz) is desired.

Just a regular ported box...tuned low...as in 26-28hz, or even lower if you really want

mlstrass
10-31-2008, 11:50 PM
I think the Q tuned around 28hz would play pretty flat and get loud...

kush-divinity
11-01-2008, 08:56 AM
Just a regular ported box...tuned low...as in 26-28hz, or even lower if you really want

I got 2 L7 12's in 6ft3 at 27 now. I kinda like it, but it tends to fall on its face in the higher regions. My port is kinda small tho, at 2x18.5x33, so maybe that causes lack of output?

It also loses power in the lowest notes, but I think that has as much to do with me starving them for power as well.

I was informed the last time I was gonna order a sub (DD3515), that the port needed to be 16in2 for every ft3 of box volume, and 16 inches long was steadfast rule. WTF is this? Sounds like it would be around 50hz peak?

I wanna do the Fi Q in 7ft with at least 120in2 of port. Tell me wassup wid dat.