tuning a box lower after it was already built?

[jsluss17 10+ year member]

i built my box for my sa-12 tuning it at 32 hertz and i wish i could tune it lower than that. is there any way i could tune it lower without removing anything? like if i could just add on to it or something because i'd like to get the lows better

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[Ninesvnsicks 10+ year member]

Longer ports = lower tuning.

 

[Moble Enclosurs 10+ year member]

The problem with that is, changing the physical parameters of the enclosure after it was designed originally, will change the way the driver performs, not so much as just how the box performs. Because our hearing can adjust quickly to these changes, many people do not notice a difference after a few days, but parameters such as excursion and power handling may change, which will create a different load for your amplifier as well. I'm just saying, altering a box after it is already built for a specific driver, can make it possibly undesirable and can change the way the driver performs all together. And its possible you may want to end up doing a new one after a while. I would recommend another design from scratch, because tuning is not a controlling factor in most designs built for music. ..since that is the sole purpose of your request. We need to not rely so much on tuning frequencies as we do cutoff points and passband response as a whole.

 

[Bettr n' Revrse 5,000+ posts]

How much lower do you want? Sounds like someone should have bought a Skar not and SA lol

 

[fasfocus00 5,000+ posts]

you could also line the walls with polyfill batting, wont work wonders but will do what you want.

 

[Danometal 10+ year member]

If your box has a slot port, you can add another section to the inner port by going through the sub cutout, and attaching with L brackets, and then using silicon or whatever. You will have to calculate the total loss of net volume to get your new tuning though. Another method is to add a piece of mdf to the port wall(s) to reduce the port area, which will lower the tuning. Also, adding polyfill will lower tuning by a couple hz. I've used all 3 methods in the same box with great results. My frankenstein box is still going strong in my Nephew's Cherokee. It hits way lower than it did originally.

 

[Vossy 10+ year member]

Last resort you could cover some of the port

 

[hispls 5,000+ posts]

If your box has a slot port, you can add another section to the inner port by going through the sub cutout, and attaching with L brackets, and then using silicon or whatever. You will have to calculate the total loss of net volume to get your new tuning though. Another method is to add a piece of mdf to the port wall(s) to reduce the port area, which will lower the tuning. Also, adding polyfill will lower tuning by a couple hz. I've used all 3 methods in the same box with great results. My frankenstein box is still going strong in my Nephew's Cherokee. It hits way lower than it did originally.

This^^^

Really I can't see tuning a box for a 12 like that any lower than you are. If you really need sub 30hz you should have either gone for more cone area, or a LMS or XBL^2 or other exotic technology driver.

Have you tried even just moving the box around, aiming different directions, firing sub at walls? Often just the position and aiming of the box wil make more difference in overall response than just tuning up or down a few cycles.

 

[Danometal 10+ year member]

Oh yea, keep in mind that, if you can't afford losing any net volume, reducing the port area will not affect your volume, but adding inner port length will. A 4th method to consider is to build an external port to attach to the existing port opening. You can wrap it around the box or something, but it will be epic ugliness for the eyes.

 

[Bass Addict 10+ year member]

not to deviate from this guys thread but i have a question on my box that does pertain to this thread and if someone could help me figure my tuning and cubic^3,i would appreciate it.love my box.i would really like to know the "EXACT" tuning though.

box is;

30" wide with a double face 3/4" mdf

16" deep

13 1/2" tall

slot port is 2 1/2" wide

12" tall

around 14" in total length

here is the kicker,i had this box originally in my house with a plate amp bolted to it.i took the plate amp out and put a 10x10" 3/4" piece of MDF mounted on the inside of the box to cover the whole.anyone want to help me figure it out ? yea,its a frankenstein box as well.when i get my havoc,i want to build a box to this tuning as i love it

 

[Phoenix Risen 10+ year member]

got bass....

make your own thread.

 

[pro-rabbit 5,000+ posts]

not to deviate from this guys thread but i have a question on my box that does pertain to this thread and if someone could help me figure my tuning and cubic^3,i would appreciate it.love my box.i would really like to know the "EXACT" tuning though.box is;

30" wide with a double face 3/4" mdf

16" deep

13 1/2" tall

slot port is 2 1/2" wide

12" tall

around 14" in total length

here is the kicker,i had this box originally in my house with a plate amp bolted to it.i took the plate amp out and put a 10x10" 3/4" piece of MDF mounted on the inside of the box to cover the whole.anyone want to help me figure it out ? yea,its a frankenstein box as well.when i get my havoc,i want to build a box to this tuning as i love it

Just a quick estimate would be 2.3ft3 after displacements and 43hz or so for tuning. I could be wrong as I just did that off the top of my head while waiting in traffic.

For the OP-

What are the specs on your enclosure? This would help more then just guessing at everything. I agree with mobile though. Better off to start again if you don't like the output of this enclosure.

 

[TheUnderFighter 10+ year member]

I'm not sure how well it works, but I know Poly-fill is supposed to trick the driver into thinking it's in a larger enclosure, which could help your driver hit the lows better. Also, SKARs are known to hit the lows quite a bit better than the SA's, just for future reference.

 

[Bass Addict 10+ year member]

Just a quick estimate would be 2.3ft3 after displacements and 43hz or so for tuning. I could be wrong as I just did that off the top of my head while waiting in traffic.

really ? 43 ? wow i thought it was lower than that ! im really surprised that this d6 is hittin the lows extremely well then

 

[pro-rabbit 5,000+ posts]

really ? 43 ? wow i thought it was lower than that ! im really surprised that this d6 is hittin the lows extremely well then

Is your length right? I have not double checked my math yet, but it should be close to accurate at least.