G23 stock sub upgrade and Fi IB3 review

[nyryan2001]

Team- thought I would share a recent project on my G that just turned out great. Upgraded the stock 10" Polk on 200w to a 15" Fi Audio IB3 on about 550w. It's an infinite baffle sub. That is in addition to a ported Treo 12" on 1500w.... That I had in there first with the 10" Polk just disconnected, and considered the 12" needing a little more.

First, I wanted huge sound.... At a budget.... And absolutely not give up ANY storage space anywhere, as I store big surfboards and such down there, and want to maintain a clean un-intrusive install. I love the over the top stereo setups... But not for my budget or the way we use our boat.

Going in to this I can say it was a leap of faith. I had never heard an IB sub in a car or a boat I would consider due to poor sound quality and weak performance. Other than modest mid bass...Most sound thin, weak and weazy. Low freq's are embarrassing. The IB3 was the biggest heaviest IB sub I could find.... Without getting into the insane home theater stuff.

Listening to this with the 12" unplugged I was thoroughly impressed with its sound quality. Lots of sub travel and excursion, move a lot of air, Sounds like it's mounted in a 1" thick solid MDF tuned box. Sounds solid. Sounds deep. Tight bass. DEEP bass... Deep bass that travels, perhaps deeper than the ported 1500w Treo. Very impressed. Together, they straight hammer.

I do have a vent cut into the walkway to assist in letting the bass radiate. Of course, fiberglass had to be cut larger to fit.

But what I will pass on is for those looking for a solid sub upgrade over the 10" Polk..... Without loosing storage...Give this a strong look. I will upgrade the amp it's on to around 750-850w at 2ohms. The 550w I have it on now isn't enough, can definitely handle more.





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[nyryan2001]

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[Laketexoma]

Nice.

[David Analog]

I totally get it. There is no legit reason why an infinite baffle sub cannot perform well if the mounting baffle is absolutely rigid and if there is total front to rear acoustic isolation with adequate air volume behind the sub.
The primary difference between an infinite baffle sub and an air suspension sub is that air suspension is a more linear form of suspension, meaning that it can better control the cone movement at a longer excursion. However, with the surface area of a 15-inch, you don't need excessive excursion to move tonage of air.
Btw, the factory Polk Audio woofer, while used in an IB application, is not a true IB woofer so it never had a chance.

[kopp210]

I am looking to give this a shot. I pulled the factory 10 and poked my head around in there. I was hoping to be able to close in the compartment and get a good sealed enclosure sub in there. After looking in there that is not easily possible.

Do you think the IB sub is plenty loud on its own? I read some good reviews of AE IB subs on car audio forums.

[kopp210]

One issue I could see is the compartment will change size based on the level of the front ballast bag. Other than that the spaces are totally separate.

[David Analog]

The Polk Audio subwoofer used by factory is actually a decent driver, but it is not a true infinite baffle (IB) woofer, so it really doesn't stand much of a chance living up to its potential in an infinite baffle application. It sounds way better in a small sealed box.
The immediate displacement of the area behind the structure will vary with the ballast but that may not be as big of an issue as what you might think. An IB woofer is looking for an enclosure of a minimum displacement that will not alter the woofer's damping (or 'Q'). Any displacement larger than the minimum requirement up to an infinite volume will not change the woofer's performance. So with an IB woofer, if the space is large enough at a minmum then any larger size change is completely forgiven. Most of the woofer's referenced are kind of quasi infinite baffle subs in that the 'Qts' is much lower than a dedicated infinite baffle woofer would be so they are still a little dependent on air spring from the enclosure (or rear air space in this case). More important than the exact enclosure displacement is that the enclosure is fully isolated front to rear for a distance of at least a quarter waveform of the lowest frequency you want it to reproduce and that the enclosure boundaries are somewhat rigid within that scope. Certainly the mounting surface must be extremely rigid, and just as rigid as you would have on a small sealed enclosure. So the factory surface could use a bit of reinforcement.

Later this year, and I'm not sure exactly when, JL Audio will be delivering a true 12-inch marine infinite baffle subwoofer. It will be a monster with a 4-inch voice coil.

[nyryan2001]

Yep, it'll change some when that front sac is filled. I haven't heard it yet with sac filled... But thrilled with results how it sounds now. Needs more power. The Fosgate T-500 it's on now tests 550w at 2ohms at 14.4v. At rest at 12.6v it's prob giving 460w or so, the IB3 can handle a lot more.

I'm gonna find an amp that does 750-850w range at 14.4v and 650-750ish at 12.6v for it at some point.

And here's the finished product.....with a Polk 15" grill to protect it from gear down there.





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[sixcampbells]

I may have to try this. Doing lots of research now! Great post. Thank you.

[Guntersville230]

Anyone know if the 10" sub in a 230 is in a sealed area or just "open air." Not a stereo person but seems like I should be getting more hit our of the sub than it produces? Input?


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[Guntersville230]

Should have mentioned, a 2015 230 with sub behind driver seat.


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[Laketexoma]

Anyone know if the 10" sub in a 230 is in a sealed area or just "open air." Not a stereo person but seems like I should be getting more hit our of the sub than it produces? Input?


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it is a infinite baffle. So yes it it a open air.

[SCNautique210SAN]

Anyone used the JL Audio M7-12IB for their IB replacement?

[MLA]

Yes

[SCNautique210SAN]

MLA how did you like it? Obviously knowing that two non-IB 12s are always going to outperform a single IB 12, how did you like the performance of that JL?