Fi Technical

What up everyone! Newbie to this forum!!! Just want some opinions on going sealed with my Q18s. I read a couple of threads on here were some folks are running their Qs in sealed enclosures and they seem to like it. Currently mine are in a 12.3cu enclosure tuned to 30hz and I pulled a 146 @ 39hz with it. Here a link to my current build http://www.*****.com/board/ind...?showtopic=3714 Vids http://www.*****.com/board/ind...?showtopic=8473 I've got good sq now but want better and I think going with a big sealed enclosure would do it. Want you guy's opinions! Thanks!

Hi All, So I've had my two 12" SSDs in a sealed box, 1 cu ft chamber for each sub, for almost a year now hooked up to a Sundown 1500D. It seems like I don't get the lows like I would expect and I'd like it to be a little louder. Do you think it would help to build a ported box for these guys to see if I can squeak anything else out of them, or is it possible that these subs just don't fit my wants? Thanks.

I am buying 4 15's and I wanted to know which was the better choice. I understand that they both have the same RMS wattage I am going for more spl and lower bass. I wanted to know which sub would produce more bass in the lower octave. I have no problem as far as space I just wanted to know which produces more output.

I'm putting a Q10 in a sealed box and am looking for a good size for SQ. The website recommends .2 to .6 cu ft. I should have 1000 watts @2Ohms available. Would a larger or smaller box lend itself to better SQ. Thanks.

Hey i have a fi q 15 dual 2 and i have it in a ported box about 3.25 cubes tuned to 33hz and i wanna try to make a 4th order bass reflex box but i havent the slightest idea how to make one. i know its more math but i havent found a how to go on how to make the and which formulas to use to calculate the box sizes and ports. Im pretty good at car audio but i just need to get pointed in the right driection on how to make it. A local car audio installer whos a wizard with boxes is trying to teach me how to make one but he is just too busy right now to help me with my box.

I tried to get the most port area possible using an "L" slot-port. The box is 39"x18"x18". I wasn't paying attention to this when I designed (threw together) the box. Fi recommends 12-16 square inches of port for every cubic foot of interior volume. 48-64 I have 74.25 square inches of port and 44" length giving me a tuning freq of 31hz. And here's my question, should I (could I) do something (short of taking the box apart) to reduce port area, and raise tuning? Specifically, can I cut another 3/4MDF piece to fit snuggly in the port to bring the width from 5.4 to 3.75...or similar?

Any thoughts or ideas on 2 12" FI BTL's (Fully Loaded) in 5 ft^3 with almost 154 in of port area????? Tuned at 32 hertz.... I understand that it is going to be an extremly long port almost 71 inches. but i have ideas for that.....Planned on using 14 inch round pvc pipe with a few 90 degree elbows in it. and how would u go about measuring something that has that many bends. Also i planned on the port having its own chamber with only the end into the part of the box where the subs are to reduce flexing and hopefully where more air flow goes into the port. But it might be a crazy idea. So if anyone could give me some feed back it would be great!!!! Thank's, Brock

Hi, can anyone link me to a thread that explains the change in the ~2006 to ~2010 motor that's used for the Q? I bought a Q15 back in 2007 and the motor for my new Q12 looks much different. The old motor has a double-stacked magnet setup. The searches I've done haven't come up with any info on this change.

does my 1997 4 door bravada (exact same as 4 door blazer) have enough space for 2 18" BTLs? or would i be better off going with 1 18"? either route i go i will have 2kw rms to EACH woofer... my max dimensions are 48w 30d and 20h.. going ported if it is only enough space for 1.. does anyone think 2 12" BTLs will be louder than 1 18"??? sorry for all the questions.. they may seem pretty dumb but i want to be sure about what im doing BTW I'm looking for a pretty good SPL but i want to retain SQ for daily listening right now i am running 2 MTX T9512-44s on 2.4kw @1ohm, in 4.5 cubes each ported tuned to 35hz, i would like to have about the same SQ as these if any one has h…

Hi everyone. I've been reading up on Fi Car Audio and in particular the Q series of subwoofers. I really can't wait to start getting my cash together for one of these bad boys. However I have a small knowledge base problem. I don't understand the exact effect of a larger box volume for a subwoofer. In particular I've read that the recommended box size for a sealed Q 15 is 2 - 2.6 cuft. Now, would the subwoofer get louder if the size was 2.6cuft vs 2cuft? There is more air to be moved in a 2.6 vs a 2 correct? But if this is true then would there be any other effects of having a larger box beside the obvious space consumption in the trunk? Bonus question: I listen to a lot …

well not really, i still have to double baffle it, and carpet it. its 4.5 cubes, 67.5^2 inches of port at 34 hz.

a americanbass 500.1 move 2 BTL 18''in a box 13cf tunin to 33hz only daily use thanks

So I just ordered two of these X 10's without really paying close attention. I have an Audiopipe APSM1300 amp that does 600@2ohm and 1000@1ohm. My question is are these subs maybe a little underrated because I've also read these amps might be a little overrated. I can always turn the gains and bass level down and go easy on the volume knob. Does this sound like it may work? I dont really have much more of a budget for subs. Im also not looking to be real loud.

Fella's, I was wondering would it be better to fire my 12" BL's forward in my SUV or to the rear towards the tailgate? I cant fire them up so its either forward or backwards? Thanks in advance.

I may be getting a blown Q 18" in a trade with a gentelman over on ROE, I want to recone it down to a 15" or a 12" , probably a 15". The guy said Scott quoted him $75 for an 18" recone kit, how much is the 15" and the 12" recone kit plus a 15" or 12" basket.

right now i have a alpine i got from a guy and i dont know much about it its a alpine mrv-t303 but i want a new one and i was wanting to know which kind would be best a link to one online would be great

As some of you are aware, I have a pair of Q15's sealed in a 4.4ft^3 enclosure. I had to build the box ackwardly to make it fit in a G35(sedan) trunk. I enjoy competing at local comps, but want to see if I can increase my output. I am pretty steady with hitting ~148db at the dash. My question for you box gurus is with the given specs of my sealed box only being 4.4ft^3 would I still get an output increase if I added a pair of external 4" aero ports (actually just pvc) and how long should they be to tune to ~34hz? Specs again: Sealed 4.4ft^3 (2) Q15's Desired tuning approx. 34hz using (2) 4" round ports What length?

I have two MA XL15s that I want to recone. how do I go about doing that. Must I ship the subs to FI? here is a picture of the sub in case people don't remember them

Just what the topic says, i need to know the diameter of a BL 12 magnet.

OKay so i got my car back... 15" Q in a (supposed to be) 4 cu.ft. ported box.... i love it so far and sounds great. i need to listen to it more tommorw. i hardly had any time today. but anyways, to the point... My box is 4 cu. ft. which means the port should be 48-64 square inches.... well i have 4 3" ports which is: 1.5^2 x 3.1415 x 4 = 28.2735 if the box is 4 cu ft and i replace the 3" ported with 4" ports, that would give me about 50 (50.264) square inches but how much would it take from the rest of the box? how would it change the sound and output? and how hard would it be to change the ports out? I think it may be restricting the sub a lil with such lil port area...…

I was just wondering, if when adding a port to your box do I minus the width of port and then I'll have my true area of space the actual woofers will be in?

So I have a problem I am getting ready to make a ported box for my BTL 12 that is fully loaded. my big question is how do I tune my port to 32hz? the dimensions are 18w x 14h x 20d which comes out to be 2.20812 cubic feet. can I please get some help and advice I used a slot port calc but I guess the port length looked funny to me. Subwoofer Enclosure Calculators, Fraction to Decimal, Parallel, Series, Port Length and Volume Calculators Thank you

Question What is the highest and lowest tuning that you all know of for the differnet series of the Fi lineup? AA would also be considered. Personally I would be most concerened with 18s and 15s I currently have 1 15" BTL dual mag in 3.8CF and tuned to 35hz Many people including myself (surprise) are really impressed by the output of this sub/enclosure combo I however have realised that (to know surprise) the cabinet is not capable of playing the lowest notes. Really needing more airspace for lower simpler tuning abilities, the box is great for "most people" and say a "rocker" type listener. Now since I myself am a rocker, Staind, Linkin Park, Korn, come to mind mo…

i need to order a recone and basket for my MT motor..and ive heard statements on both sides of my question. does the BTL coil fit in the MT gap?

iam building a box will 41 INCHES BY 21 INCHES BY 22 " be fine for the sub and how many cubic feet would that be thanks for any help !!