Ported Shiva-X?

[bdavies11 10+ year member]

I've been thinking about putting my Shiva-X in a ported box in my camaro tuned somewhere in the low 30's. The box I have is currently sealed but there is plenty of depth to it to drop a couple of 3" aero ports in there. The box is somewhere around 3 cu.ft. (too big for a 12" sealed) which is part of the reason I'd like to try it ported.

My question is, would you guys think two, 3" flared ports about 11" in length be enough to keep port noise away? The sub will be on about 500 watts.

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[thegreatestpenn 5,000+ posts]

it should be okay, but I'd personally use 2 4" aeros or 1 6" aero

 

[bdavies11 10+ year member]

Ya, I'd love to go with two 4" ports just to be safe but it appears they'd have be a bit too long to fit in the box if I want to keep the tuning in the lower 30's. I'd rather not have the ports sticking out of the box, but rather flush with the baffle if ya know what I mean.

 

[Papermaker85 5,000+ posts]

its going to be very peaky, if your going ported id use 1.75 tuned to 28.. 20 in^2 is plenty..

 

[bdavies11 10+ year member]

Can I ask why you think it would be peaky? I would think just the opposite with my sub/box combination. From what I understand, the Shiva-X likes larger enclosures than most subs. 1.75 seems a bit small for a ported design with this driver.

 

[T3mpest 10+ year member]

I've been thinking about putting my Shiva-X in a ported box in my camaro tuned somewhere in the low 30's. The box I have is currently sealed but there is plenty of depth to it to drop a couple of 3" aero ports in there. The box is somewhere around 3 cu.ft. (too big for a 12" sealed) which is part of the reason I'd like to try it ported.
My question is, would you guys think two, 3" flared ports about 11" in length be enough to keep port noise away? The sub will be on about 500 watts.

3 cubes at 32 hz produces a fairly strong hump around 40-45hz. For listening to young jeezy or something of that nature it will get pretty loud and hit alot of rap bass lines very well. Still won't be a super low end monster if that's what your looking for. These subs don't lend themselves to being ported very well at least not in a vehicle, but as always it depends on the curve your lookingfor. In order to get the majority of your bass boosted near tuning you need a very big box and at that point, it gets very peaky. Anyway after graphing it, unless your goal is to be super peaky I'd tune as low as you can. Figure out the max port length you can fit in that box, you may want to just use external aero's. I'd tune at 27 if you can, 25 being more ideal for 3 cubes.

Also your sealed box isnt' too big at all. Your overall q is about .6, which is fine, especially off of 500 watts. Your almost running into xmax with that power at like 20hz. IMO, that box is about perfect.

 

[bdavies11 10+ year member]

3 cubes at 32 hz produces a fairly strong hump around 40-45hz. For listening to young jeezy or something of that nature it will get pretty loud and hit alot of rap bass lines very well. Still won't be a super low end monster if that's what your looking for. These subs don't lend themselves to being ported very well at least not in a vehicle, but as always it depends on the curve your lookingfor. In order to get the majority of your bass boosted near tuning you need a very big box and at that point, it gets very peaky. Anyway after graphing it, unless your goal is to be super peaky I'd tune as low as you can. Figure out the max port length you can fit in that box, you may want to just use external aero's. I'd tune at 27 if you can, 25 being more ideal for 3 cubes.
Also your sealed box isnt' too big at all. Your overall q is about .6, which is fine, especially off of 500 watts. Your almost running into xmax with that power at like 20hz. IMO, that box is about perfect.

Very interesting T3mpest, I appreciate the info. I've never really heard of anyone tuning an enclosure in a vehicle lower than about 28hz. As far as I know there isn't much music that even extends down that low. Are you making an exception just because of the specs of the sub? I don't want to tune too low and not have any output up higher but also don't want it peaking around 45hz like you mentioned. I'd much rather have it stay as flat as possible with maybe some extra strength down low for some music.

I'm not out to set any SPL records or anything but I've always felt that I've lacked good low end output in my car.

 

[Papermaker85 5,000+ posts]

low fs woofer tend to lack the proper dampening for ported applications, there also very peaky around tuning..

if you really want to port it at most 2 cubes but be warned its going to drop of pretty fast above tuning any larger..

 

[T3mpest 10+ year member]

Very interesting T3mpest, I appreciate the info. I've never really heard of anyone tuning an enclosure in a vehicle lower than about 28hz. As far as I know there isn't much music that even extends down that low. Are you making an exception just because of the specs of the sub? I don't want to tune too low and not have any output up higher but also don't want it peaking around 45hz like you mentioned. I'd much rather have it stay as flat as possible with maybe some extra strength down low for some music.
I'm not out to set any SPL records or anything but I've always felt that I've lacked good low end output in my car.

yes it's mostly an exception due to the sub. Like I said by tuning at 32 your actual hump from the tuning being there is at 42hz or so. If what you what is a flat extended response that will dig deep, then tune much lower than coventional wisdom would suggest for that sub in a box that size. 28hz looks fine and might be easier to fit.