Featured About IB Enclosures

[Blackout67]

Thinking about doing an IB setup for my Mustang. My first question would be how hard is it to seal these holes in the rear deck? A cheap option would be multiple layers of cardboard sealed with duct tape with CLD over top, but not sure if that would be adequate. Maybe 1/8 ABS plastic, tape, and CLD? Does it need to be 100 percent completely sealed?

2nd I know IB is a more SQ oriented build that requires much less power, what kind of power and size/amount of drivers would be necessary to get a good 130ish DBs? I know thats a variable answer question but not sure if anyone else with IB setups could advise their general experience. Also, Subsonic filter: unneeded or necessary?

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[Buck 5,000+ posts]

I mean technically I think it'll be like large sealed if you seal off the trunk. You want to get drivers designed for IB or free air where they don't need mechanical loading / air cushioning from the box. I haven't done IB specifically but done t-lines which can be super similar with the lack of chamber loading compared to ported. What I'd do is just try to maximize cone area, find woofers designed for IB that has Fs that'll allow you to play it where you want to.

Yeah I'd say you want it as sealed as possible because if it's not then the leaking bass from the trunk may cancel out the bass in the cabin. You might check out HPDE plastic to fill holes, you can buy sheets of it, or just use wood and a wood to metal adhesive, just cut the wood to fit. Seal the trunk good and the rest is up to the woofers. I'm not an expert in IB-supporting woofers but I know you want a woofer designed to handle rms power free air, which many audio woofers people use in car audio aren't specifically designed to do so. If I was going to do this as well as possible to be loud as possible, I'd aim for completely hard sealed trunk and the most cone area with the most rms rating and xmax, try to get the best combo of those.

 

[Blackout67]

I mean technically I think it'll be like large sealed if you seal off the trunk. You want to get drivers designed for IB or free air where they don't need mechanical loading / air cushioning from the box. I haven't done IB specifically but done t-lines which can be super similar with the lack of chamber loading compared to ported. What I'd do is just try to maximize cone area, find woofers designed for IB that has Fs that'll allow you to play it where you want to.

Yeah I'd say you want it as sealed as possible because if it's not then the leaking bass from the trunk may cancel out the bass in the cabin. You might check out HPDE plastic to fill holes, you can buy sheets of it, or just use wood and a wood to metal adhesive, just cut the wood to fit. Seal the trunk good and the rest is up to the woofers. I'm not an expert in IB-supporting woofers but I know you want a woofer designed to handle rms power free air, which many audio woofers I people use aren't designed to do so. If I was going to do this as well as possible to be loud as possible, I'd aim for completely hard sealed trunk and the most cone area with the most rms rating and xmax, try to get the best combo of those.

Yea ive read that low FS high xmax drivers with low compliance are the way to go. Most subs oriented towards IB setups send to be crazy expensive. I was looking at the Earthquake Tremor series they have a low fs and high xmax and are like $280 a pair for the twelves. I'd have to do some measurements, i wouldn't be able to fit an 18 without makeing a more complicated baffle. Maybe 15s. Twelve would def fit tho

What would be the difference in going with HDPE vs ABS?

 

[Buck 5,000+ posts]

Yea ive read that low FS high xmax drivers with low compliance are the way to go. Most subs oriented towards IB setups send to be crazy expensive. I was looking at the Earthquake Tremor series they have a low fs and high xmax and are like $280 a pair for the twelves. I'd have to do some measurements, i wouldn't be able to fit an 18 without makeing a more complicated baffle. Maybe 15s. Twelve would def fit tho

What would be the difference in going with HDPE vs ABS?

I'm not sure what the difference would be between those plastics.

Yeah, IB woofers are maybe more specialized, just the nature of what they're required to do means they have to I think be designed more precisely, I think it's maybe a different standard, because most subs we typically use in car audio use the box to control themselves, making a woofer have to control its full movement under full rms with its own suspension I think takes more work. I mean 2 15's would probably sound pretty good I'd imagine, that would def be some bass haha

 

[shredder1 10+ year member]

Going the IB route means cone area usually for that output and impact most seek. Also there are a select number of subs that are truly compatible, while they may perform well expect a significant lowering of power handling as a direct result of the IB setup. The IB setup that comes to mind was Todd's Celica. 2-15's in a Gel-coated trunk /w/ xtant amps. Pretty decent output on under 1000w.
In my experience IB is a nice solution for people who want HT tuning in a vehicle... Combined with a STRONG frontstage a IB can perform but only with a strong midbassy front.
Most opt for the seal-off and dont modify for excessive cone, but compatibility, integrity and cone area are the first 3 rules regarding install when IB is considered. Forget big power handling #'s and understand what you're building.

 

[Jimi77 Premium Member]

I'd just use MDF or plywood to seal the holes. You want high QTS. Anything above .45-.5 will do. If this is for SQ, then you don't need a ton of xmax. FS doesn't need to be particularly low either since you cabin gain will kick in early in small coupe. Mechanical power handling will suffer.

 

[Jimi77 Premium Member]

Going the IB route means cone area usually for that output and impact most seek. Also there are a select number of subs that are truly compatible, while they may perform well expect a significant lowering of power handling as a direct result of the IB setup. The IB setup that comes to mind was Todd's Celica. 2-15's in a Gel-coated trunk /w/ xtant amps. Pretty decent output on under 1000w.
In my experience IB is a nice solution for people who want HT tuning in a vehicle... Combined with a STRONG frontstage a IB can perform but only with a strong midbassy front.
Most opt for the seal-off and dont modify for excessive cone, but compatibility, integrity and cone area are the first 3 rules regarding install when IB is considered. Forget big power handling #'s and understand what you're building.

Agreed. Should be able to do two 15s in a Mustang trunk. Two 10s or 12s will be enough for an SQ system.

 

[shredder1 10+ year member]

Agreed. Should be able to do two 15s in a Mustang trunk. Two 10s or 12s will be enough for an SQ system.

People cringe when told modifying the structure of the parcel shelf or the permanence of the modification. Last one I was involved in was 2 15s and required the entire lip of the parcel shelf removed for the cone height. Then 3/4" material was used in place of that wimpy crap the factory uses for the rear deck. Foamed into the remaining metal structure with gussets on the bottom inside the trunk /w/ a 1/8' medite upholstered trim panel covering everything. It was permanent make no mistake.
Rear stage deleted of course (that was a fight) and 8" in the front doors, 6.5 in the kicks /w/ 2" softies in the pillars and a ton of active Eq.
It didn't hit or slam so to speak but was impressive in its own way. I prefer a well designed T-Line over IB for that sound myself.
Jmo

 

[Blackout67]

Going the IB route means cone area usually for that output and impact most seek. Also there are a select number of subs that are truly compatible, while they may perform well expect a significant lowering of power handling as a direct result of the IB setup. The IB setup that comes to mind was Todd's Celica. 2-15's in a Gel-coated trunk /w/ xtant amps. Pretty decent output on under 1000w.
In my experience IB is a nice solution for people who want HT tuning in a vehicle... Combined with a STRONG frontstage a IB can perform but only with a strong midbassy front.
Most opt for the seal-off and dont modify for excessive cone, but compatibility, integrity and cone area are the first 3 rules regarding install when IB is considered. Forget big power handling #'s and understand what you're building.

I do plan on also doing a full sealed front stage for the mids. I picked up a set of Recoil Components thats im going to switch over to Dayton classic woofers too which from what they say performs well in a car door. Trying

Im not concerned about big numbers. I prefer a more efficient setup as im not planning on getting a high output alternator. I have a JP13 to play with which is extremely efficient at 4 and 2 ohms. 91 percent I believe. I've had my experience with big ol stuff woofers wired at one ohm with terrible efficiently and im never happy with it. Sealed sounds good but efficiency goes out the window. I want something that'll blend nicely with the front stage when playing rock and metal, but also want to be able to have a nice chest hitting louder subwoofer stage for rap or any song where bass is the main focus.

Do you have any recommendations for cheaper IB drivers? I dont want to be s0ending $400 per woofer. Maybe $200ish. Besides the cheap Tremor series, I was looking audio the HO or UM series from Dayton Audio. Any idea if those would be good?

 

[Blackout67]

People cringe when told modifying the structure of the parcel shelf or the permanence of the modification. Last one I was involved in was 2 15s and required the entire lip of the parcel shelf removed for the cone height. Then 3/4" material was used in place of that wimpy crap the factory uses for the rear deck. Foamed into the remaining metal structure with gussets on the bottom inside the trunk /w/ a 1/8' medite upholstered trim panel covering everything. It was permanent make no mistake.
Rear stage deleted of course (that was a fight) and 8" in the front doors, 6.5 in the kicks /w/ 2" softies in the pillars and a ton of active Eq.
It didn't hit or slam so to speak but was impressive in its own way. I prefer a well designed T-Line over IB for that sound myself.
Jmo

Im not afraid to do any small modifications. Just dont want to be cutting a whole into the body of the trunk like Nicks 24 inch IB setup.

Rear stage delete is easy on the mustangs. I just need to know the best and most cost effective way to seal the front and back waves from eachother.


Would a Tline be better here? Im not opposed to having a box but from my understanding, T lines get kind of unwieldy due to the size, especially for larger drivers with more port area making the labyrinth massive

 

[Buck 5,000+ posts]

I can't imagine you'd fit much of a t-line in there, t-lines tend to be pretty big.

If your IB isn't good you can always port it too if there's enough room on the face, make entire trunk ported chamber, allow rear bass into cabin through ports. Not sure how that would sound exactly but just a thought.

 

[shredder1 10+ year member]

Would a Tline be better here? Im not opposed to having a box but from my understanding, T lines get kind of unwieldy due to the size, especially for larger drivers with more port area making the labyrinth massive

I'd personally do a pair of 8s or a single 10maybe a single 12 in a Tline but understand its the same bs... low power. With today's subs and efficiencies for the most part they require an enclosure. Ever have a legit tuned ported enclosure done by a legit designer? Either way its goals and willingness to sacrifice space. Understanding your options goes well beyond what you hear. To experience a well designed ported enclosure should silence any concerns. Some drivers perform and others really perform in their environment.
Those 3 laws still apply.

 

[shredder1 10+ year member]

Do you have any recommendations for cheaper IB drivers?

I almost never meaning I avoid recommendations regarding any equipment. Especially something that you as the user should be all over. Its your baby so make it work.

I prefer a more efficient setup as im not planning on getting a high output alternator. I have a JP13 to play with which is extremely efficient at 4 and 2 ohms. 91 percent I believe. I've had my experience with big ol stuff woofers wired at one ohm with terrible efficiently and im never happy with it. Sealed sounds good but efficiency goes out the window

Jeez... almost sounds like a future ported guy. I used to be a sealed guy about 20yr ago

 

[shredder1 10+ year member]

In a Mustang I'd do 2-10's in a 4th myself. Just understand ratio and cabin peak. The right subs help too. Its a hard won experience to do it right.

 

[Blackout67]

I'd personally do a pair of 8s or a single 10maybe a single 12 in a Tline but understand its the same bs... low power. With today's subs and efficiencies for the most part they require an enclosure. Ever have a legit tuned ported enclosure done by a legit designer? Either way its goals and willingness to sacrifice space. Understanding your options goes well beyond what you hear. To experience a well designed ported enclosure should silence any concerns. Some drivers perform and others really perform in their environment.
Those 3 laws still apply.

Yea i had a custom made box for a 15 inch but it was in my other mustang and due to the size was sitting on the rear seats and it never sounded right to me. I've also made a few shitty boxes that sounded alright but looked pretty bad.

It terms of a 4th order I'd have no idea how to design one. If Im using a box im going its gonna be built by me. I like doing it and practice makes perfect.

IB is tempting to me because of the ease of installation, atleast in terms of a baffle thats a couple of cuts then sealed to the trunk hole vs a box designed and then cut and glued together by hand myself (isolating sound waves is obv a whole other deal), as well as the efficiency and SQ that is talked about with these builds.