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Discussion Starter · #1 ·
Alright guys! Quick rundown..
Currently, I am running the oh-so-loved Acoustic Elegance IB12s in an infinite baffle. Feeding them roughly 200w each.
Given the music I listen to/ music I make (part of Bass Mekanik records), the low-end rolloff just does not work for me (steep drop at 29hz). If needed I am willing to sacrifice a few dB (1-3) for extended bandwidth (trying to get response down to roughly 25hz)

What I am wondering is, if I were to swap subs to a different set of 12s, but include a 3rd one (which will raise me from a 2ohm load to 3ohm) will the added cone area of a 3rd 12 negate the effects of a loss in power?
What other effects could be noted?

(Subs that I will change to are still in question - have a few in mind, feel free to ask if needed)

Thanks!
 

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Discussion Starter · #3 ·
Recently did some testing.. dropped to a single AE getting ~200w @ 4ohm. VERY similar output, probably a 2db difference. 36hz and below suffered dramatically.
I'm thinking it would help, but I can be wrong.

I would do the changes now if i could.. Broke college student, checking in. Research before buying anyway :)
 

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Discussion Starter · #4 · (Edited)
Do you have the room to just step up to a pair of 15's instead?
I wish. Car is a 1996 Mercury Sable..we have weird trunks. If i want to keep enough room for a wheelchair (which I do) I only have 13".
In theory, I CAN do 2 15s, but the basket would hit the deck. I'd have to have a 6+ layer baffle just to make it fit, and at that point its just not worth it

Edit: Depending on the basket layout, it may work. Would it be a challenge? Yes, but it can be done.
Just did some remeasuring, sorry about that.
 

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I would think cone area would give you better results. Adding power to get more output will increase the excursion needed by the subs to play the same level. So you have to take into consideration how much available excursion you have and how much you already use. If you're already near the limit of what your sub is capable of your gains will be minimal with more power.
 

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Discussion Starter · #6 ·
I would think cone area would give you better results. Adding power to get more output will increase the excursion needed by the subs to play the same level. So you have to take into consideration how much available excursion you have and how much you already use. If you're already near the limit of what your sub is capable of your gains will be minimal with more power.
For this one, I'm actually losing power ang gaining cone area. The subs I am looking at (jbl gto 12) have a good rep. RMS on them normally is 300w, so giving them just a tad over 100w in an infinite baffle would put them relatively close to xmax
 

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Discussion Starter · #8 · (Edited)
IMHO, I think you'd be downgrading by switching to the GTO's. It's a lower quality sub and your not going to hardly gain any output. I'd stick with what you have until you can do it proper. with more power, more xmax or more cone area. Something along the lines of three ID Max12's with 1000w would be an upgrade. :D
Mentioned earlier, I can run 2 15s with a bit of a baffle upgrade. If all i upgraded was cone area (might go id-q 15s, or some other upgrade) would I notice a difference at all?
Upper end response is quite nice. Have them crossed at 125hz. Can be dropped to 80hz easily with minor tweaks to my doors

Also I dont need super high end stuff :p i dont have an ear for the super fine details and i dont plan on competing or anything. Just looking for a nice daily driver
 

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Discussion Starter · #9 ·
I'd go with the ib15's. You'll notice the difference. 35% more cone area and same Xmax, still very efficient 200w will be plenty, they play down to 20Hz with ease, super clean low distortion deep bass, basket is very small for a 15 iirc it's only 6" depth.
But then again, finding them is the real challenge here lol.
May just end up going 15s. The JBL GTO 15s have been broven to work (believe the owner of ID used a pair for a customer) and would be cheaper and easy to get
Guess its all what happens first
 

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The IB12s should have no problem going below 29hz and with very little EQ.

Unless you're using up all of their available excursion, displacement is not the problem. How is adding more displacement going to help when displacement is not the limiting factor? If they were bottoming out then you need more displacement. Not many 12s have TS parameters as conducive to getting low as the IB12s do.

Is the subsonic filter on? How much excursion are they seeing?

The low end is affected the most in an IB setup (at least in two of mine) where the trunk and cabin are not sealed from one another. Mine has nearly the same response from 40hz and up with some pretty significant leaks. 20-25hz suffers the most before sealing.

You mention a wheelchair. How much of your trunk is taken up with the wheelchair and any accessories? Have you checked response with the trunk empty?

I just added a pair of 15s with considerably more displacement than my IB15s and they most certainly do not get lower or louder on the same power.
 

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I would consider lowering the noise floor with sound deadening first before chasing new subs. MLV or even a cheaper barrier like db-3 from home depot could get the job done. The only important factor is lb/sq ft.
 

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I would consider lowering the noise floor with sound deadening first before chasing new subs. MLV or even a cheaper barrier like db-3 from home depot could get the job done. The only important factor is lb/sq ft.
db-3 from home depot is the ONLY thing I'd be looking at. .75lb/sq ft isnt' great, but it's not bad and it's so cheap you can double up on it and still come out ahead and heavier. Free shipping ftw.
 

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Discussion Starter · #13 ·
If I can find a used pair of ib15s at a decent price, I'd be able to also upgrade my amp.
Being strapped fit cash really sucks
 

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Unless I've found the wrong specs, those are small sealed box woofers. Qts of .38?

Rather than changing subs, I'd suggest getting a parametric EQ of some sort. If you reduce the peak above 36 Hz, then you'll have flatter response through the whole bass range.
 

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I would want to find out why they're dropping off so early. Those subs should have no problem going as low as he wants. They're extremely efficient down low. None of my questions were answered so I guess we have a case of someone wanting to swap equipment instead if trying to figure out what's wrong.

In the beginning 15s and another amp were out of the question. Now all of a sudden they're an option? We don't know if the trunk stays full of wheel chair gear. We don't know how well the cabin is sealed from the trunk. We don't know if the subsonic is on. It sucks when people take the time to try and help and it's too hard to respond.

Throw 4 18s and 4kw at it. I'm sure it will fix your problem. That is unless the subsonic is on or the trunk is too small.
 

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Discussion Starter · #16 ·
I would want to find out why they're dropping off so early. Those subs should have no problem going as low as he wants. They're extremely efficient down low. None of my questions were answered so I guess we have a case of someone wanting to swap equipment instead if trying to figure out what's wrong.

In the beginning 15s and another amp were out of the question. Now all of a sudden they're an option? We don't know if the trunk stays full of wheel chair gear. We don't know how well the cabin is sealed from the trunk. We don't know if the subsonic is on. It sucks when people take the time to try and help and it's too hard to respond.

Throw 4 18s and 4kw at it. I'm sure it will fix your problem. That is unless the subsonic is on or the trunk is too small.
Since this was late at night, my attention was not full.
Lets go from the top; 15s and a new amp can be had within my price range, so it is a possibility. I just needed to remeasure some things.
It is full of wheelchair stuff once to twice/ week. Not mine, but my friends stuff. I need it to fit.
Baffle could be better done.. i will be covering more holes and removing rear deck speakers, and covering those 6x8 gaps as well. Hoping that will make a difference.
SSF is nonexistant on my amp.
No need to be rude homie :) (sorry if you werent) like i said, was 2am and did not have my full attention.

I would absolutely love to keep these ae 12s. If i need to re-do the baffle then i will
 

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Discussion Starter · #17 ·
I believe these are the specs.

IB12AU-4ohm
Fs: 24 Hz
Qms: 3.8
Vas: 160 L
Cms: 0.4 mm/N
Mms: 110 g
Rms: 4.35 kg/S
Xmax: 18 mm(peak)
Xmech: 22 mm(peak)
Sd: 530 sqcm
Vd: 1.92L (p-p)
Qes: 0.59
Re: 2.7 ohm
Le: 0.16 mH
Z: 4 ohm
Bl: 8.75 T/m
Pe: 500W (cont.)
Qts: 0.51
1WSPL: 88 dB
2.83V: 92.5 dB
A few questios regarding the specs..
Mine are not the AU model. These are just the good ol' ib12s.. how far off are they?
Also, is that 500w PE a freeair number, or a boxed number?
 

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The reason they're dropping off down there is because the low Q makes the response flatter lower. Coupled with cabin gain, the response is more like a vented box. Buy an EQ, reduce the peak and increase the amp gain.
 
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