fi btl 18

Hey guys I was wanting to get 2 18inch fiblts with a hifonics 2500.1 amp! But my question was will 2 18s fit in a 1995 grand am trunk? If any body know please let me know! Thanks alot!!!8)GrandAmGT

good luck trying to get approx. 10 cubic feet of box space in the trunk for two 18" woofers. or you might try building an isobarik box  for both speakers. However, building an isobarik box is tricky and it takes some expertise and everything needs to be exact and you need to know the specs of the speaker as well.

Having large speakers in an automobile does not mean you will have a better sounding system. You could easily build a box with two 12" or two 10" woofers and it would sound great and shake the car as long as you build the right size box and build it properly.

Good luck on two 18" woofers in a trunk with it sounding good.

jpeterman15

Well I was thinking i might just get  2 or 3 12 inch fibtl n212s or 2 or 3 audio que SDC2.5sGrandAmGT

I am sure you heard the saying "bigger is not always better". I would have to say this would be true with two 18" woofers. You would be better off with two 12" woofers since trunk space is limited. I can pretty much guarantee you would be pleased with the sound and the shaking of the vehicle. With your trunk space and the specs of the audio que SDC2.5 you would be able to build a box that would fit. Your box would need to be approx 1.5 cubic feet per speaker with an approx port size being 3" diameter by 5.75 inches long. Total box volume being 3.0 cubic feet with each chamber being 1.5 cubic feet. The same size volume would also work with the 12 inch fibtl n212 speakers. happy building and good luck. let me know how it turns out.jpeterman15

jpeterman15 wrote: However, building an isobarik box is tricky and it takes some expertise and everything needs to be exact and you need to know the specs of the speaker as well.

First... I have to know why you need to know the specs for the drivers for an isobarik load, but you don't have to know the specs for the drivers for a standard loading... Second... Why is an isobarik enclosure any more difficult to construct than any other type of enclosure, and why do you feel it has to require any more expertise and care in construction than any other system? Basically, what I am asking is this: What makes an isobarik enclosure different in your mind?It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

An isobaric box is designed to house two woofers in one box at half the internal volume of what it would take for one woofer. There are different ways to house the woofer inside the enclosure and also outside the enclosure, if you chose that application. You also have to be more precise on port measurements if you decide to use a vented system. Plus the woofers can't be wired the same, one woofer has to be wired out of phase so you have a push pull effect. Please excuse me for not saying you need the thiele-small parameters for any speaker you build a box for. There are different designs for isobaric enclosures such as your standard acoustic suspension, compound loading which I am talking about, planar loading, isobaric Quasi-sixth order, Dual reflex bandpass enclosure, isobaric three chamber dual reflex bandpass enclosure, Quasi-eighth order series and so on. The names alone are difficult to say. Building an isobaric box to me is a little more difficult than building a simple square or rectangular box for one woofer. Isobaric to me is a different animal. Isobaric is not that popular anymore since simple box design has become more advanced and tested to be just as effective and or more effective. Also, just trying to help.jpeterman15

I was kidding... I've been iso-loading woofers forever. I was "sorta mocking you" with my question, specifically because of what you said about needing to be much more careful in your construction, specifically the measurements, when iso-loading. There is no need to be any more careful in an iso design than in any other design. T/S parameters are mandatory in all cases, although there are some cases where not all of the parameters are necessary. All of the alignments you just named can also be built with a single driver. Three benefits to iso loading are power handling, enclosure size, and linearity. Two MAJOR detriments to iso loading are cost and efficiency. The improvement in linearity alone would never even allow me to THINK about building any type of iso loaded bandpass. Isobarik loading is an "audiophile" load, and putting them into a band-pass enclosure would simply ruin the capabilities of the iso load. When deciding on an iso alignment, you must decide if the trade-offs are necessary or desired. The cost to output ratio has NEVER allowed them to be popular, I promise you. All I am saying is that you don't have to treat the enclosure contruction any different than you would treat any OTHER type of enclosure. iT IS THE VERY SAME ANIMAL. Just smaller. Proper bracing, measure twice - cut once. SEAL THE CORNERS. Bracing. Oh, and BRACING!It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

If you are an accomplished box builder then why are you asking people on this forum if two 18" woofers will fit in the trunk of a grand am? To me that is a question posted by someone who is a novice in box building and looking for a little info, obviously you are a projpeterman15

I was also thing my dad told me he would sell me his 03 tahoe for $1500 if I give him my grandam, so I will pri just do that and put like 2 to 4 18" fibtl's in that.GrandAmGT

and by the way my name is grandamgt95 i asked the question not haemphystGrandAmGT