# IB subs in ported enclosure



## kryptonitewhite (Sep 1, 2008)

To me, I like certain specs and choose my speakers acordingly, then I determine what box I would prefer for the location it needs to fit in. I like low Fs, high Xmax basically. I have a grasp on most of the Thiele/Small, but not a thourough knowledge on all of them. Example, I get Mms is the mass of the moving parts combined with the mass of the air it moves. A thick heavy cone, larger coil, weighted dustcap...and a larger Sd creates larger Mms, which lowers Fs, lowers transients? (I have ideas but don't know)... yadda.

So I have a feel of things, but at the end of the day, I want a large clean stroke and I like smooth responce and low extention. I am a Tumult/Brahma/Avalanche/Maelstrom-X/Tempest-X kinda guy. RL-p not so much, they look awesome, but the rubber/plastic doesn't fit the same mould to me though the motor topology, not being XBL^2, is similar and parameters are similar.

But I don't believe in EBP. I know it works, it's tried and true, but I know which drivers I like, but if I have almost no room, I know the above subs will sound great in a sealed enclosure. If I get enough room to go ported and low, then I will reinforce the low end. I am just now getting into IB.

So I'm not getting my Avalanches back, the Maelstrom-X's don't have much for coil options, so along comes this cheap yet awesome Fi IB18.

I have a daily driver that my woman drives with my son. She's not into systems yet, but curious. We need trunk space, and not a whole lot for output. (I'm a basshead, so by not a lot of output, I mean I was going to run just the pair of 15" Avalanches sealed)

I might throw 1 IB18 in there in a large sealed if i can't get enough airspace to tune sub 30's.

I would like to get another dedicated SUV someday and wall 2 IB18's @ 16Hz for fun and wow factor.

I would like to build an IB manifold as well.


So couldn't a guy get the 4 or more IB18's for the deal, and use them in different enclosures and all function just fine?


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## Mike P. (Apr 6, 2007)

> I might throw 1 IB18 in there in a large sealed if i can't get enough airspace to tune sub 30's.


Model the IB18 in whatever size box the above would be and compare it against a box that is 10 times the Vas, which is what the IB18 was designed for. This comparison will show you the difference.


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## kryptonitewhite (Sep 1, 2008)

I just ran out and measured the trunk as conservatively as possible. The one I am worried about most is trying to throw an IB18 in a trunk.

External 40" X 20" X16"

3/4" mdf, slot port all along the back and up 1 side to the front... 3" X 18.5" X 53"

Internal airspace about 3.7-3.8 cubes after sub displacement (terrible!) but 26Hz tune!

Will this work? 

otherwise sealed would be a nice 5.8-5.9 ( NOOOO!!!! )


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## Mike P. (Apr 6, 2007)

Are you suggesting an IB18 in 3.8 cubes tuned to 26Hz?


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## kryptonitewhite (Sep 1, 2008)

I would do nothing of the sort kind sir! :R

I was wondering if an IB18 would be OK confined to 5.5 - 6 cubes sealed :T


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## Mike P. (Apr 6, 2007)

It would work but it would be a waste of the subs capabilities. In 6 cu.ft. sealed with 600 watts input the sub would only use 16mm of its 30mm Xmax. That's modeling with the Fi IB18 specs, I'm not sure if the new Fi IB subs have the same specs or not as they are not yet posted.


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## kryptonitewhite (Sep 1, 2008)

I want to say so bad that it can probably handle much more than that, but especially not after seeing Scott's post about being happy to be dealing with HT more, and not liking car guys trying to throw 2 gigawatts at 250 watt subs lol.

I feared there wouldn't be an easy "fix" to my sub situation. I fear I need to find different subs for different applications...so i can still get 4 IB18's and I'll just have to run all 4 IB in home :bigsmile:

As for the car, I don't even know if i will do either... daily or dedicated :huh:

(edit: and in-car will see much less excursion than that even)


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## Mike P. (Apr 6, 2007)

Car or home, staying within the manufacturers recommended limits is what gives years of trouble free service. 

*Just Say No To Recones!* :bigsmile:


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## kryptonitewhite (Sep 1, 2008)

hehehehe..... ok ok ok, youre right... I have learned that lesson enough.

So I'm thinking for the car, i already have a dual sealed box for a pair of 15's built...I should check into a pair of those Tempests, look for some used Tumults, or...

How about a Maelstom-X in that same box? I keep hearing the thing likes up to 3000 watts...

OK...fine...I'm gonna go look up manufacturer recommendations now :whistling:


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## kryptonitewhite (Sep 1, 2008)

Alright Mike,

So I got to read a little on the LLT... and i'm glad I did. While fantasizing about these IB's, I kept finding myself wanting to "cheat" it to use the rear wave any way. I need to stick to large and low tuned.

But, I was thinking earlier, how about using an IB18 infinite baffle in car? I mean the in-car definition of sealing the trunk off and mounting the sub in between the two. I know the trunk won't give 10X Vas.... but would this work well? It would make me a little less annoying driving by from front to back cancellation, I think it would require considerably less power.... still a decent FR curve???


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## Mike P. (Apr 6, 2007)

How big would the trunk area be?


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## kryptonitewhite (Sep 1, 2008)

I would have to take some measurments tomorrow, but it's an average trunk, and will totally not fit HT definitions... but i'd have to say for a general car IB, should be neat. I'll snap some pics too, and try to put in some things for size references.

, i will see if the GF will come out with me right now!

back ina bit.


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## kryptonitewhite (Sep 1, 2008)

2004 Toyota Camry


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## Mike P. (Apr 6, 2007)

From what I can find, the trunk volume of a 2004 Toyota Camry is 13.8 cu.ft. With a Fi IB18 you would only be using 22mm of the 30 mm Xmax in that volume. If you really want to go loud and low, port a Malestrom and use the whole trunk for the cabinet and tune it to 16 hz.









Add to that the crazy amount of cabin gain. Josh did a test in a Jeep WJ and got 36db gain at 9.5hz.

http://www.hometheatershack.com/for...led-ported/14209-monster-quest-room-gain.html

(5th graph from the top.)


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## kryptonitewhite (Sep 1, 2008)

I think in real world, the subwoofer would still have decent excursion at its suggested power rating, especially since a trunk will be tough to make air tight... so factoring losses and leaks and such. And I hate to say it out loud, but I think another 100-200 watts would be OK... I'm thinking the power rating is assuming IB, not IRRC or whatever... I would guess in a 2 cu ft sealed enclosure, 800 watts wouldn't kill it, would it?

And I just saw there is now a 15" version! 



We are talking about this IB18, right?

The new IB 18 features a 3" coil and a triple stacked motor specific for the IB application (smaller than the older Q series modified IB drivers and a little more purpose built overall).
Specs are:

Re 1.5 Ohms (single 2 Ohm coil)
Le .87mH
Fs 22.9 hz
Qms 3.25
Qes .79
Qts .63
Vas 381 l
Mms 258 g
Sd 1210 cm^2
Spl 89.4 1W/1m

Xmax is 30mm and suspension and motor limit right about at the same time.
At about 500-600 W it hits its linear limits at 20Hz. Power needs will vary accordingly.



Now... about this Maelstrom-X...  I love this idea. No one has ever given me the go ahead to do 16Hz in car! I'm ecstatic, but the ol lady does want some trunk space, and I don't see how I could fit a box in there big enough any way to get 16Hz!

But I'm listening....


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## Mike P. (Apr 6, 2007)

> Re 1.5 Ohms (single 2 Ohm coil)
> Le .87mH
> Fs 22.9 hz
> Qms 3.25
> ...


Those specs are from a year ago. Fi just release a new series called the IB3.

https://ssl.perfora.net/www.ficarau...Speakers/0050_IB3/product_overview.shopscript

Still waiting to find out what the parameters are. As for the Maelstrom-X, I was just putting it out there. I'm out of my element with this. If you're really interested in the IB possibilities, head over to the SSA forum. There's way more knowledge over there regarding car audio IB installs.

http://www.soundsolutionsaudio.com/forum/index.php?


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## kryptonitewhite (Sep 1, 2008)

I was trying to argue as much as possible to exhaust this unfortunate want I have to work with Ascendant/Fi. Stupid, and I apologize.

I am normally the 1st to get stuck on the very best, even if it means spending considerably more unless things go over the top.... I really wanted a 15" Tumult back in the day, but then the Avalanche price thing happened making it possible to get it now, not half a year saving. It drove me nuts all the people that got the Atlas instead simply because it was cheaper.

I really do want the Mael... it's got 3 more mm, it's got the 40mm headroom, and it's got the lower Fs.... I totally know I really want it for the extra 150 bucks. I know I do, but I keep trying to talk myself into getting a bunch of IB18's instead of 1 Mael-x at a time.

When I argue with ya, I know I'm coming to you for knowledge... I'm pushing you a little I guess to convince me a little more.

This Mael is obviousely more suited for a car, any car amp will have a lot more power and I'll need user-error headroom. I don't know that IB will work for it, because that arch in the rear seat/trunk opening is only 13" tall, and total height its just barely 20". If I did it, I'd have to slant the baffle, having to work around every groove, and it would come out past the wheel well... and we can't cover that! I don't see an 18" destined to be "" IB "" in that car, no matter the driver. Could do a pair of 10's or a 15", but I want to start using 18's now.

I do see finding some way to squeeze a single 18 in there though, 1 way or another, that we will be satisfied with.

Still hangin with me?


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## Mike P. (Apr 6, 2007)

> unfortunate (want) I have to work with Ascendant/Fi.


That was 3 years ago. It's a whole new ball game now. Clean slate. :T



> It drove me nuts all the people that got the Atlas instead simply because it was cheaper.


And I reget it. Almost everyday. :duh:




> but I keep trying to talk myself into getting a bunch of IB18's instead of 1 Mael-x at a time.


Whether you convince your self or not on the IB18's, nothing is going to change the graph in post #18. Both subs will respond to your application differently. It depends on what you want and what you're willing to accept performance wise.



> Still hangin with me?


Still here. :yes:


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## kryptonitewhite (Sep 1, 2008)

OK... so I can't use the whole trunk for the enclosure... I'd love to, but we have a 6mo old and it's crazy enough she's letting me do anything at all. So believe me, if/when I do my dedicated, I've already made another thread on the SUV I plan on doing with dual 18's walled @ 16Hz.... 

Are you thinking no IB for the Maelstrom in this either? 





Here's 2 threads on my dedicated...

http://www.hometheatershack.com/for...s-dual-18s-8hz-bottom-c-stuffing-effects.html

http://www.avsforum.com/avs-vb/showthread.php?t=1074047

Man, I hope I can do that as well! Too many fish to fry  we can start with this daily driver that will keep me and mom happy, w/o poppin Hudson's ears!


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## kryptonitewhite (Sep 1, 2008)

here's what we will probably throw in the daily driver for front stage, I'll just start from scratch with the dedicated if that ever comes about.

4 Adire Audio Extremis 6.4's, I have a Kicker KX850.4 for them and an Audio Control 6XS, I need to get a second one so I can bandpass the 4.5's and 6.5's with a 24dB slope for everything.

They will cover 50Hz-750Hz (same as Kit LCR crossover points)






















2 Adire FR125S's...only available 8ohm. I have a Kicker KX350.4 that I will bridge for these.

They will cover 750Hz-3.5kHz











And 2 Vifa XT25TG30 1" Ring Radiator Tweets doing 3.5kHz on up











the inside of my first sloppy resined enclosure that had 1 Ava, 4th order, I designed on Shavano.com before I knew how to use BBP6 and WinISD. S factor of .7 and F3L of 20Hz.


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## kryptonitewhite (Sep 1, 2008)

Mike P. said:


> From what I can find, the trunk volume of a 2004 Toyota Camry is 13.8 cu.ft. With a Fi IB18 you would only be using 22mm of the 30 mm Xmax in that volume. If you really want to go loud and low, port a Malestrom and use the whole trunk for the cabinet and tune it to 16 hz.


by this, do you mean by "sealing off" the trunk as much as possible, and sticking a port through?

or, do you mean build a real enclosure, ported? because the whole point to all of those pics was to show how it's just like every other trunk... very mis-shapen. I gave the largest dimensions possible earlier if I plan to build a true enclosure of wood. I believe around 40" wide, 20" tall, and 16" deep?

Thanks!


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## Mike P. (Apr 6, 2007)

> do you mean by "sealing off" the trunk as much as possible, and sticking a port through?


From what I've seen on the SSA forums, an IB is mounted on a baffle on the front of the trunk and the whole trunk is used as an enclosure. My thought was why not port it. I'm guessing here. The whole trunk as a cabinet would be 13.8 cu.ft. if the specs I read are correct. A box 40" wide, 20" tall, and 16" deep would have a internal volume of 6 cu.ft. if 3/4 inch building material is used.


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## kryptonitewhite (Sep 1, 2008)

thats what I was guessing you meant. i'm guessing you used the highest number in WinISD to factor in air leak loss ? I would guess a trunk, even after sealing it off from the cabin, sealing the tail lights, the air vents that allow airflow throughout (there are generally 2 large vents from the trunk to the outside of the vehicle to let air flow through the windows in front and out the trunk), maybe even modifying the trunk lid gasket...everything...even then would be much less airtight than a normal wood enclosure?


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## Mike P. (Apr 6, 2007)

> even then would be much less airtight than a normal wood enclosure?


Probably yes. The biggest issue would be the trunk lid.


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## kryptonitewhite (Sep 1, 2008)

So here's what I'm thinking... I have a Lanzar OPTI2000D, and they might do a run of dual 2 Maelstrom-X's. 1 IB? If 1500 watts isn't enough to bring it to full excursion in 13.8 cubes IB... I will still be totally happy :bigsmile:

The FR curve would be more fullfilling than a "smaller" sub that would be used to it's fullest potential :hush:

(If I could do a true LLT of wood, trust me, I'd say we don't need the trunk baby, there's room on both sides of the carseat and the floor! )

But porting a trunk....let's just call it a day as IB!

Now I suppose we need to be careful of popping the trunk with the system on...


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## kryptonitewhite (Sep 1, 2008)

Mike P. said:


> Car or home, staying within the manufacturers recommended limits is what gives years of trouble free service.
> 
> *Just Say No To Recones!* :bigsmile:


So we are back to this again, as I am now communicating directly with Scott about the IB series 18" and 22".

First I will re-quote this post by him on the specs, and would like everyone to note at the end about power NEEDS varying according to application, as we all know....



Fi Audio said:


> We have a new email specifically for the new IB series subwoofers from Fi. Any questions regarding the new 18" and 15" can be directed to [email protected]. Hopefully this will eliminate some of the back up of IB emails being caught in the flood of regular car audio emails.
> 
> The new IB 18 features a 3" coil and a triple stacked motor specific for the IB application (smaller than the older Q series modified IB drivers and a little more purpose built overall).
> Specs are:
> ...









Now that doesn't say that more than 600 watts is acceptable, but this email does...




Jordan,

Well the issue with the power handling is not a thermal one, but mechanical. With IBs you dont have an enclosure to help control excursion and are relying solely on the drivers suspension and linearity. Due to this the IB3 series is rated right around 600W @ 20Hz. Again this isnt a thermal limit as the coils can handle double that. But a mechanical one... and if you set the frequency limit lower, the power limit would be set lower as well. It takes 4 times the excursion (or volumetric displacement) to have the same output (anechoically) one octave lower. 
I can meet the below requirements with ease, but you have to be aware that the trade off would be sensitivity... and to that point I really dont see a good reason to simply add more power to something simply because you can when the 1W/1m drops to do it. Id much rather go with something that meets the desired goals at a higher sensitivity level and not have to run more power to it. 

What vehicle is it going into?

Also, I will be gone for the next week and hope to have email while I am on the road... if not, have a Happy Holidays and Ill talk to you on the 29th.


Thanks,
Scott
Fi Car Audio















An IB18, when properly done in certain alignments, can thermally handle double the 600 watt rating... 1200 watts per 18.

I have been trying to say this for how long?!

But I am glad I didnt just jump on it and go for 1 or 2 of them, because I will probably go with a 22"


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## Mike P. (Apr 6, 2007)

> I have been trying to say this for how long?!


Which we all knew. The point is it had to come from the manufacturer, after all, it is his product.


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## kryptonitewhite (Sep 1, 2008)

Mike P. said:


> Which we all knew. The point is it had to come from the manufacturer, after all, it is his product.


Well now we have it... who wants to see a 22" in 15-25 cubes @ <20Hz? I just went out to start the car, and we are still right in the middle of this blizzard.... I'm not measuring anything today!


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## a1161979 (Aug 26, 2007)

Mike P. said:


> Whether you convince your self or not on the IB18's, nothing is going to change the graph in post #18. Both subs will respond to your application differently. It depends on what you want and what you're willing to accept performance wise.


WinISD graphs and in car response = very little relation, There is a reason why most guys in car audio build from experience not from WinISD which tells of a theoretical response in half space (please correct me if im wrong) there is much more to car audio and also much less, the reason i say that is the best way to get a good response is with a smalled SQ sub and a little EQ :T 

Of course they will sound different but not as the graph has portrayed :daydream:


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## kryptonitewhite (Sep 1, 2008)

a1161979 said:


> WinISD graphs and in car response = very little relation, There is a reason why most guys in car audio build from experience not from WinISD which tells of a theoretical response in half space (please correct me if im wrong) there is much more to car audio and also much less, the reason i say that is the best way to get a good response is with a smalled SQ sub and a little EQ :T
> 
> Of course they will sound different but not as the graph has portrayed :daydream:


experience is what i have an abundance of


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