[Audi-A3]

Just looking for some input, as well as a couple of questions. I‘m thinking of going to an IB set up this winter. Right now running a JL 10W3 in a pre loaded high put put wedge. Going after more Sq , and the 10 I have now gets plenty loud for me. also want to keep the same amp/power.

1. - would 1 Adire tempest 15 with 300 watts work, or would 2 12’s be better way to go (same power).
2.- What’s the difference on having the sub cone facing the back seat or into the trunk ?
I‘m still in the planning and research faze of this. So just looking for input an options, need to keep things at 2ohm for the amp.

 

[gijoe]

A pair of 12’s has more surface area than a 15”. So that’s most likely what I would go with, but in some ways it depends on the subwoofers being considered.

It makes no difference which way you face them, chose whichever fits/looks best.

 

[LimpCroissaint]

It's kind of just which way you want to compromise. Like Gijoe said, you'll have more cone area with the two 12's, which will result in about 6 db more output than one 12 (3 db for doubling surface area, and 3 db for "doubling" power since you'll have two at the same power). However the 15, if you're looking at the same model as the 12 will dig a little deeper. I'm a huge fan of large subwoofers because it just brings a huge smile to my face when I get to feel those super low notes. But I'd have a hard time on the same decision too.

 

[Ali-323i]

Depending on the sub, if there’s any motor noise, it may help facing the cone to the cabin. Otherwise it’s just preference / aesthetics.

My first trunk IB was a 12w3v3 on 300rms, and was surprisingly great!! Dug plenty low, and hit into 133 on music that was probably hitting the 32-34hz range.

If you can do two subs, I’d suggest it, and then it’s always easy to add more power (within the sub limits) as you desire for more (often inevitable in this hobby!).

Choice of sub will be key also, as good as the W3 played (I preferred it in IB to the sealed box I had, which also sounded great), something like an IDMAX, SI SQL, or a few others will likely do even better still.

Good luck and keep us posted!!

 

[daloudin]

Just looking for some input, as well as a couple of questions. I‘m thinking of going to an IB set up this winter. Right now running a JL 10W3 in a pre loaded high put put wedge. Going after more Sq , and the 10 I have now gets plenty loud for me. also want to keep the same amp/power.

1. - would 1 Adire tempest 15 with 300 watts work, or would 2 12’s be better way to go (same power).
2.- What’s the difference on having the sub cone facing the back seat or into the trunk ?
I‘m still in the planning and research faze of this. So just looking for input an options, need to keep things at 2ohm for the amp.

Are you considering a true IB setup or a Trunk Baffle setup? We can model the possibilities either way just need to know your trunk volume and if it's got vent baffles or not.

 

[Audi-A3]

Depending on the sub, if there’s any motor noise, it may help facing the cone to the cabin. Otherwise it’s just preference / aesthetics.

My first trunk IB was a 12w3v3 on 300rms, and was surprisingly great!! Dug plenty low, and hit into 133 on music that was probably hitting the 32-34hz range.

If you can do two subs, I’d suggest it, and then it’s always easy to add more power (within the sub limits) as you desire for more (often inevitable in this hobby!).

Choice of sub will be key also, as good as the W3 played (I preferred it in IB to the sealed box I had, which also sounded great), something like an IDMAX, SI SQL, or a few others will likely do even better still.

Good luck and keep us posted!! View attachment 307572
View attachment 307573

This is what I’m thinking install wise. I have the fold down sec in the middle of the back seat. That’s why I was leaning towards 1- 15.

 

[Audi-A3]

Are you considering a true IB setup or a Trunk Baffle setup? We can model the possibilities either way just need to know your trunk volume and if it's got vent baffles or not.

I’m thinking trunk baffle, with closing off the rear deck. It has an opening for a factory 8”. My thought was the use the under side of the rear deck for the amp rack… ?

 

[daloudin]

I’m thinking trunk baffle, with closing off the rear deck. It has an opening for a factory 8”. My thought was the use the under side of the rear deck for the amp rack… ?

What year model and is it AWD?

 

[Audi-A3]

What year model and is it AWD?

2018 yes AWD.

 

[MF Toker]

If you're talking subs within the same line and similar xmax I would almost always go for two 12"s vs one 15". You will likely end up with higher power handling, similar sensitivity, and slightly more displacement capabilities. If not then model them all up.

 

[daloudin]

So according to Google you have a ~9.9 cuft Trunk (the AWD takes up an extra 3 cuft over the FWD model) so we model potential candidates in a 10 cuft Sealed Box.

The Adire Tempest 15 is not gonna work in the space - it won't handle 300W in 10 cuft it - excursion limited at about 200 Watts at 20 Hz. Resonance is not really low enough to give you the IB type response.

Right of the top of my head the one sub that I know that works in 10 cuft sealed is the Dayton Ultimax 18-22 (which is either dual 2 Ohm, Series 4 Ohm or One Ohm Parallel and will handle 500 W in 10 cubes so that's another problem) and here's what they look like in WinISD:

 

[Audi-A3]

Wow thanks for all that. I’ll have to look for a different driver, or set up. Truly appreciate all of this. As it’s saving me a lot of time and money.

 

[Audi-A3]

Would something like this work better?

IB3 Series – IB312 v2 | Fi Car Audio

ficaraudio.com

 

[DaveG]

Previously posed a similar question to @daloudin that may be of some help.

Looking for someone to model 2 subs in Winisd for me...

Fellas can one of you Winisd experts model 2 scenarios for me please? Trunk baffle - 14.8 cubic feet trunk #1 - Two AE SBP12-4a on 600 watts #2 - One AE SBP15-4a on 400 watts Specs: SBP12-4ohm Fs: 23.6 Hz Qms: 4.22 Vas: 160 L Cms: 0.4 mm/N Mms: 114 g Rms: 4 kg/S Xmax: 14 mm(peak) Xmech: 18...

www.diymobileaudio.com

 

[daloudin]

Would something like this work better?

IB3 Series – IB312 v2 | Fi Car Audio

ficaraudio.com

Fi IB3v2 Drivers are full on IB drivers and get choked off some when run as Trunk Baffle just like the Acoustic Elegance IB Drivers but the 12S2 is better than the Tempest just not as good as the UM18-22 and the 12S2 needs at least 600 Watts into it's Single 2 Ohm Voice Coil. Still, for a Single 12 and F3 of 28.52Hz is pretty good - just remember that when using IB or in your case TB alignments cone area is king so you want to look at what the BIGGEST cone you can fit.

Notice how the Red Line for the 12S2 rolls off faster than the UM18-22, that's because 10 cuft is actually too small for the best curve - it would like to have at least 45 cuft (thus the IB design) so this reduces the low frequency extension and increases power handling slightly.

 

[Audi-A3]

Thanks for everything. Have to say I’m learning a lot. Really looks like the Dayton Ultimax is better suited to my car. That being said, the biggest I can go is a 15 and it’s a tight fit. Maybe 2 10’s would be better? More cone area, just like the look of 1 big driver… 😏

 

[daloudin]

The Ultimax comes in a 15 as well and actually puts out more SPL before excursion limiting than the 18 (finding that kind of odd - I'll have to look into that more...) and Acoustic Elegance makes an SBP15-4 that would work very well also - Here are all 3 on the 300 Watts you originally were looking at:

The UM15-22 "wants" about 7.5 cuft so stretching that to 10 for the model and then assuming that you'll have some stuff actually in the trunk from time-to-time it would probably work better than the 18 anyway. The increase in SPL over the 18 is due to the 300 Watts being about all the 15 wants versus the 18 wanting closer to 500 Watts.

 

[daloudin]

The Ultimax comes in a 12 as well and 2 of them want 9.2 cuft so here they are. The blue line is Dual UM12-22's on 300 Watts - the Single 15 beats them at 300W but if you doubled the power the 12s are better...

 

[gijoe]

A trunk is not sealed, if the advertised specs of a trunk is 10 cubic feet, simply plugging that into WinISD as the sealed box size isn't accurate. Since the trunk is vented, the subwoofer will react as if it's in a much bigger box than 10 cubic feet. I wouldn't be too worried about the size of the trunk "choking" the subwoofer. Unless you are filling a trunk with several 15's, you shouldn't really see a problem.

While those graphs may be somewhat helpful in comparing a couple of subs, they aren't going to show the FR of a sub in a trunk IB situation very accurately unless you increase the enclosure volume that you are using to model.

 

[daloudin]

A trunk is not sealed, if the advertised specs of a trunk is 10 cubic feet, simply plugging that into WinISD as the sealed box size isn't accurate. Since the trunk is vented, the subwoofer will react as if it's in a much bigger box than 10 cubic feet. I wouldn't be too worried about the size of the trunk "choking" the subwoofer. Unless you are filling a trunk with several 15's, you shouldn't really see a problem.

While those graphs may be somewhat helpful in comparing a couple of subs, they aren't going to show the FR of a sub in a trunk IB situation very accurately unless you increase the enclosure volume that you are using to model.

Yes - you are entirely correct and you can model a Trunk Baffle as an aperiodically damped enclosure but WinISD doesn't have that option currently. There are other programs that can do this but starting with 10 cuft as a minimum is simply a method to get a baseline for potential candidates by eliminating Subs like the Adire that can't use an enclosure this big...

Thank you for reminding me what we are working with and that it's technically not a "sealed" enclosure.

To the OP this means that the IB subs we were talking about could be more of a candidate. Sorry for the confusion.