15 replies to this topic

[figjam2407]

Hey,

So I have posted in another thread and thought I would start another due to thread jacking etc.

I am hoping to get some insight into my current setup and whether its going in the right direction. Loud daily on a budget

Car: Impreza Hatch

Sub: DD 9515g D4 Specs attached
Amp: OA 3200
Battery: Optima D34

Im not really sure if the box it is currently in is ideal.
Could someone perhaps do a calculation for me regarding size and tuning.


Forgot to add, the depth of the port is 410mm

Thanks

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•  Box.bmp   522.72K   17 downloads

Edited by figjam2407, 15 March 2012 - 08:45 PM.

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[Lunchbox.inc]

my math tells my that's 5.3cf tuned at 26hz... with 25 sq inch of port (based on single 18mm construction)...


the physical box size i would say is a nice spot, big, but suited to lows... however i would say the port is small, and tuned a little too low for your normal music selections, unless your sitting there listening slowed or chopped and screwed i doubt you really need to be tuned that low...

however, are you 110% certain those are the measurements, to the millimeter...? just so my measurements are correct...

[figjam2407]

Yes I remeasured just then to make sure. The depth was 510mm of the box not 505mm.

I should have mentioned it is made from 25mm MDF so I have provided external measurements only.

Thanks Lunchbox. I thought it sounded a bit average

[Lunchbox.inc]

well based on 25mm and being 510mm deep, not 505mm... it's actually 4.9cf tuned at 27hz

but still much the same as above...


personally i'd look at a little more port area, and a slightly higher tune depending on what you like to listen to...

[figjam2407]

Thanks Lunchbox.

In terms of altering port size, do I need to make another box?

[Lunchbox.inc]

usually a new box, altho overall a bigger job, usually turns out to be the easier approach...

i personally haven't used the 95series woofers, so i'm hesitant to offer any real advice on exact sizing etc, so i'll let someone who has some more experience with the woofers throw it out there,

but yes, usually a new box is the easier way to go about it, but there's no reason why you couldn't attempt to modify this box?

[Sorin-Andrei]

If Steve's calcs are right and you're thinking of building a new box, i'd say you need to go a slightly smaller box @ around 4.5cu net, tuned to around 34hz. The DD subs don't generally need to be tuned so low, they can comfortably play afew Hz below tuning.

Also, it looks like your current port is only 25square inches in area, or 5sqin per cube. That's bugger all.
Also should be aiming for around 16-18sqin of port per cube, so you want a port that is around 80sqin in area.

Best compromise i can make out with your current box setup will be if you widen your port to 100mm. This will give you a port area of around 14sqin per cube, and a box around 4.2cu net tuned @ 36hz which would be ideal for music. If you're chasing numbers, a 125mm wide port will get you 4 cubes and 40Hz tuning, but won't get as low.

[~Samuel~]

Sorin is spot on.

You want less volume, more port and a high tune.

We have both played with 9915 and 9515's and Sorins recomendations of 4ish cubes tuned in the mid to high 30's is spot on

[figjam2407]

Just before I alter the box, is it work getting a peak of the car?

Posted from my portable device.

[D34M0N.inc]

Unless its just a SPL box tuned high for comps not a music box then i wouldn't stress to much personally.

[089JAY]

Unless its just a SPL box tuned high for comps not a music box then i wouldn't stress to much personally.

Not all SPL Boxes are tuned stupidly high... I'm currently tuned around 46 - 48 hz however I have heard of people tuning as high as 60hz in CRX's and even higher in Panda's (pre 60hz limit in Street Classes)...

With tuning as low as you are I wouldn't worry at all about where the car's resonant frequency is...

[D34M0N.inc]

High for me is 40hz + though lol

[Lunchbox.inc]

lol, is it sad that i consider 35hz as a "tuned high"...?

[D34M0N.inc]

35hz is my musical tuning haha.

[figjam2407]

Well, I may have to build another box as the inside of the current one is layered with resin!
Anyone have a driver that would suit the current box?

Posted from my portable device.

[D34M0N.inc]

Just build a new box for your current sub man it's cheaper than getting a new driver