Some questions about Fi BTLs for anyone that has experience with them

 

Bronze Member
Username: Djb0501

Post Number: 69
Registered: Jul-07
Right now in my daily driver I'm running a JL Audio 13w7 on about 1100 watts. I've decided that I want a sound system that is a lot louder and a lot more powerful for more of a true SPL setup.

I'm planning on building in the back of a Tahoe with the third row of seats removed. Right now i'm looking at getting two Fi BTL 18 inch drivers. I was originally thinking of going for four, but I doubt they'll fit and I'm only removing the third row of seats. Most configurations of BTLs that i've seen require that the entire back of the car (2nd and 3rd rows) be walled off in order to fit four, but correct me if I'm wrong.

Having said all of that, I have some questions for anyone with more knowledge about the BTLs than me. My first question is about cone size. Will 18 inch drivers sound noticeably better and/or louder than 15's? In terms of how they'll fit in the back of my car is there one setup that might be preferable to the other?

I was also wondering about how to power them. The Fi Audio website says that both the 18's and the 15's run on 2000 watts RMS, but I've seen people who have four of them who claim to be running 17,000-20,000 watts in their car. How much power SHOULD a BTL be given for maximum performance without risking damage to the woofer?

My last question is about price. I was hoping someone could give me a ballpark figure for what I'm looking at price-wise to put 2-4 BTLs in the back of a car along with the right amplifiers, any additional batteries, and I'm thinking in all likelihood a more powerful alternator than the one that is in the car. (For the record, I know it's not a small job or a cheap job.) I'm only looking at the price of the woofers and anything I would need to adequately power them. I already have a set of Focal speakers that I'm going to run throughout the car, so it really comes down to the drivers, amplifier(s), battery(s), wiring, alternator, etc.

Any help anyone could give would be awesome and much appreciated!
 

Gold Member
Username: Bonhamd

Traverse City, MI

Post Number: 2191
Registered: Nov-07
troy jones is the man to talk to on this. he has a tahoe.....and he ran 4 18 inch BTLs. i think he did it while keeping the 2nd row of seats as well. his electrical is just nuts though

i see most people running 3 or 4K on a loaded BTL
 

Gold Member
Username: Kyle_lowe

Post Number: 1118
Registered: Apr-06
buying new i would say you are looking at $3,000+ with stock btl's and 2krms to each.
thats for 2 subs and not 4
 

Gold Member
Username: Delsole

Post Number: 1582
Registered: Feb-05
I would guess you looking a about 1k for the subs(for two). At least that to power them. An alternator will run you around 500 bucks. Batteries can be very pricey. I would say you gonna be looking at a little over 3k. But i would expect to pay a good amount more. You would still need a box for them also.
 

Silver Member
Username: Cwruck

Post Number: 173
Registered: Feb-10
ya the btls would be around 500 each shipped. people say you need 2k to each one to get them moving, but people push 3k to 3.5k to them and say they sound good and will last you as long as its a clean signal. now thats going to be the hard part. ive never had a system of that calibur so its hard to give advice, but from what i have learned 2 high output alts will almost be a necessity to do that.
you can find alts for decent prices if you buy them and can put them in yourself. you will also need to do a few runs of 1/0 ga wire as well, you can easily have over 100 ft of wire if not more just to power everything.
nobody ever mentions them, but optima yellow tops work great, its quite easy to talk someone down at advance auto or other places to get decent prices on them, i would recommend the d34 i believe thats the right model number, its the biggest they make, and you could have 2 of them for 400 or less depending if someone cuts you a deal.
amps are going to be costly as well, maybe look at an amp that is strapable and wire your subs to get the most out of 2 amps rather than buying 2 3000 watt amps.
sorry im sure there is a select few that have done something like this and know the right answers.
also what vehicle do you have?
im sure if its an suv you could easily fit 16 cubes in there for a box, just make sure too brace it very well.
good thing is, if you have a box so big with the subs in, you are almost guaranteed nobody would be able to steal it unless they have some strong friends with them. and mount the amps to the box with like a star type screw so someone wouldnt be able to take the amps unless they have that screwdriver which i doubt most people dont think about that if they are going to un mount an amp to steal
 

Gold Member
Username: Tejcurrent

Post Number: 2256
Registered: Apr-07
< flattered lol.

I think you're looking in the 5-10,000 ballpark for a good 4 btl setup with a ton of power. With the huge step up you're taking I'd give them 2k-2500 watts daily and leave room to upgrade amps.

Price:
subs: 4 btl 18s: ~2000
amps: 8-10kw 1500-4000 depending on amp and used/new.
Batts: 1500-2000
Alts: 1000-2000
Wire: 350 (2 spools of knu 1/0)
Box materials: 300

So at least 6000 unless you get a lot of used stuff.

It's the electrical upgrades that kill you, which is why I believe more subs > more power for most people. Let me explain that price list and some options a bit more thoroughly.

10,000 watts should have a nice few batteries. I used yellow tops, and noticed a huge difference switching to less powermaster d3100s. 3 3100s did a better job than the 5 yellow tops I had initially. Yellows are about 200 each, 3100s 350 each. $50 more in batteries gained me about .5 volt during heavy notes, with more room to add batts and less wiring. I would still recommend 5-6 d3100s for 10,000 watts.

I had 16,000 rms available if I could keep my voltage up, but I simply couldn't despite 4 alternators and a year of work on things. I would recommend 2 4000-5000 watt amps. I can sell you an alt bracket for like 200 or so that will fit 4 alternators, but you probably would be fine buying a dual kit from DC Power or something.

There's a huge difference in cone area between a pair of 15s and 18s, enough to be worth it for the price difference if you have room.
You can fit 4 btls in a tahoe without a wall, and while keeping your second row, but you wont be competing in the non-walled class. I had to make my box even with the window line and only a few inches from the rear tailgate. The BTL 18 works good in 5ft net with minimum port requirements, so 20ft net with 240 square inches of port. This box would also allow you to add more power down the road.

If you want to break 150 you'll have no problem with either setup, it's just a matter of how much money and effort you're willing to put into it.

I'm tired from too much college homework, any questions I didn't answer please let me know and I'll do my best to help.
 

Gold Member
Username: Tejcurrent

Post Number: 2257
Registered: Apr-07
As far as doing 2 btls, I would get 1 American bass 500.1, sundown 4500, or 2 audioque 2200s or similar.

Alternators and batts for that you should be fine with a nice dual alternator bracket and 3 d3100s. I believe with 4kw I could play all day at idle and maintain 13.5-14 volts with that electrical system.

That would set you back about 3000, and be pretty loud.

As far as power handling you really don't need to give them that much power in a bigger box. I gave 2 btls 4000 watts rms for years with no problems. I sold my subs and to my knowledge 2 of them were blown by sundown 3000s. BTLs will handle this power, it just depends on the setup and enclosure.
In your case why stress over smoking your money, just give them the power they're rated for and enjoy without fear.
 

Gold Member
Username: Delsole

Post Number: 1583
Registered: Feb-05
You could even try a couple of the Cresendo 3k's.
 

Gold Member
Username: Joebruce

TC Sounds/DLS

Post Number: 3031
Registered: May-04
Price:
subs: 4 btl 18s: ~2000
amps: 8-10kw 1500-4000 depending on amp and used/new.
Batts: 1500-2000
Alts: 1000-2000
Wire: 350 (2 spools of knu 1/0)
Box materials: 300

Having a sweet a*s sysytem that hot chicks will love and ask to sit in you car and listen to it and then going home and wacking it to all the hotties drooling over your "over compensating for a small c*ck" of a system...........PRICELESS!!!

 

Gold Member
Username: Tejcurrent

Post Number: 2258
Registered: Apr-07
too funny Twiztid lol.

I've never met a girl that liked systems. Ever. My wife won't even pose for a hair trick, I have to find random girls or long-haired men. And long haired men ruin it.

It's like guys dump thousands of dollars into hobbies and items to impress women and most women don't give sh/t.
 

Gold Member
Username: Joebruce

TC Sounds/DLS

Post Number: 3032
Registered: May-04
lol yea I was jus kiddin but I know some chicks that dig loud systems. They could really care less about how it sounds (SQ) all they care about is how loud it "bumps" but whatever they dont know any better. I try to learn my girl a few things but she dont really care. As long as her music sounds good shes cool.

"I have to find random girls or long-haired men. And long haired men ruin it."

I lold about the long haired men! ROFL!!
 

Platinum Member
Username: Rovin

1 15 = 153 DBs ...Trinidad & T...

Post Number: 16349
Registered: Jul-05
that long haired men post is full of LOL !!!!!


from what troy said there it seems like 4 subs & the amps\electrical for it will be damn expensive & alot of trouble but if u can afford it by all means go right ahead

i have seen\heard a few 2 15 sets that do over 152 dbs on musical tuned enclosures (about 10,000wrms behind them though) , are incredibly loud & sound great when done right so 2 18s shud be more than enough loud unless its for serious competition use which is a whole other story ...
 

Gold Member
Username: Tejcurrent

Post Number: 2259
Registered: Apr-07
It does get really expensive really fast. Honestly from the lack of response this guy sounds scared off- but even 1 btl 18 on 2000 watts is a huge jump in output.

A 2kw amp, a BTL, a replacement alternator and additional battery would only be like $2000. That may be the place to start.
 

Silver Member
Username: Cwruck

Post Number: 176
Registered: Feb-10
i cant wait to get an 18 so hopefully i can do decent hair tricks.
i can do really small hairtricks with my girl now but it looks pretty funny when i show my girl vids of hairtricks and then i do one and its all little lol, but i am only running 1 12 tuned 38 hz.. ya im surprised i can even do it.
to me it seems like mexican and black girls like systems, every now and then a white girl does but not so much. not being racist just being honest lol.
i think guys like to put systems in their cars not to impress girls, but just to gain attention, same reason a guy has an acura integra painted 6 different colors but has a turbo, intercooler and a loud exhaust and they drive up and down the main streets all day long
but with stereos for me, it seems like all those people with stereos are annoying! where i live i never see anyone with good equipment, just kenwood subs with some power acoustik 1200 watt amp.. haha i cant help but laugh
but every now and then i see someone with something decent and i like talking to them, they actaully understand a little and dont have a system that sounds horrible and is full of distortion
sorry for going on about nothing
to the op you gotta comment and say something, if it sounds like its too much for you to do let us know and you can find something to run off your 1000 watts now that will be louder than the jl since thats what you want and you dont have to worry about all the upgrades
 

Bronze Member
Username: Djb0501

Post Number: 70
Registered: Jul-07
Hey guys, didn't scare me away. Just been pretty busy with work haha.

Thanks for all the info Troy, thats actually really helpful. I'm not trying to do serious competition, I'm just ready for a setup that's a lot bigger and a lot louder and I'm finally able to afford a serious setup in a bigger car. That's why i was wondering if the difference between the 15s and the 18s would be noticeable. Will the 18s get a lot louder or just sound deeper? I know competition wise I'd need to wall it of and go for maximum power with the 18s, but I'm not really trying to compete, which is why I'm torn between the 15s and the 18s. if the 18s will be noticeably louder then those are what I'll go with but If the difference is negligible I might save a little bit of money and buy 15s. The 18s are still my preference but if the only difference will be the depth of the bass I'd rather just go for 4 15s.
 

Bronze Member
Username: Djb0501

Post Number: 71
Registered: Jul-07
Troy, would you mind posting a link to the thread with the pictures of your finished setup if you have it handy? I think I remember checking it out but I can't track it down right now
 

Silver Member
Username: Cwruck

Post Number: 177
Registered: Feb-10
the price from 15s to 18s is only like 30 per sub.. if you have the space go with the 18s. the cone area of 2 18s is almost just as much as 3 15s..
im assuming you will have an suv you will run it in, you may as well just 18s, you want to be loud and its not much more money at all
because of the fs of 18s compared to 15s 18s can go lower and be louder, but of course its all about the tuning of the box, if you want a good mix of lows and highs tune around 35 hz, but 18s may recommend a lower tuning than that..
the only advice i really gave out of all that ramblin is... go with 18s
 

Bronze Member
Username: Djb0501

Post Number: 72
Registered: Jul-07
Yeah, I checked the price and it wouldn't make a huge difference. Plus I'd plan on powering them about equally. Right now there's a 5-8 week backorder on BTLs online and i've pretty much decided that at least for the subs I'm going to buy new and go through Fi. I've had too many problems with used drivers before to drop that much cash on them and then have a used set of speakers blow out on me a week later. But yeah at this point this is pretty much turning into my projct for the summer haha
 

Gold Member
Username: Tejcurrent

Post Number: 2261
Registered: Apr-07
Good thought on buying new- it's really worth it for subs imo.
18s have the potential to be a good bit louder than 15s. My wife has also told me numerous times that my setup sounds deeper than most vehicles she hear's going down the road- but that's probably also due to tuning and overall setup.

I did 20ft net @ 36hz, but so close to the tailgate it was actually lower.

Here are a few vids:

4kw total power to all 4 18s:

Hoodie trick:



I can't find the thread on this forum, so here are a few pics:
Alternators
Upload
Rear before trim plate- 36hz removable port.
Upload
Rear with trimplate (I wish I'd painted the whole thing white or vinyled the entire box
Upload
Batts/wiring
Upload
View from inside
Upload
One of the 4 4kws, I lined them on the side of the box.
Upload

Between the wiring, weight of the box, and the amp location you could not fit the box out of the truck without an angled drill and about 20 minutes of removing amps.
 

Silver Member
Username: Sleste8

Shelbyville, MI United States

Post Number: 176
Registered: Mar-10
nice setup troy, excuse me while i go change my boxers. lol
 

Platinum Member
Username: Rovin

1 15 = 153 DBs ...Trinidad & T...

Post Number: 16352
Registered: Jul-05
man that wiper flex is super CRAZY - i like how functional ur rear view too


a set that wud be nice & not kill ur bank acct wud be something simpler like 2 audioque 18s with a single AQ 3500d , 18s move alot of air & by using a less current hungry set u wud save alot by not necessarily needing more than 1 ho alt & a bunch of batts ...less weight in ur ride means lower gas bills too .....
 

Silver Member
Username: Skdooley

Roanoke, VA Usa

Post Number: 779
Registered: Oct-09
The light fixture coming loose on the ceiling says it all. That was an impressive set up Troy.
 

Gold Member
Username: Delsole

Post Number: 1586
Registered: Feb-05
very nice.
 

Silver Member
Username: Gcs8

Atlanta, Ga

Post Number: 537
Registered: Sep-09
OT: hows your dual 21's doing troy haven't seen them in a wile.
 

Silver Member
Username: Skdooley

Roanoke, VA Usa

Post Number: 784
Registered: Oct-09
We need some videos of those babies destroying the Tahoe
 

Bronze Member
Username: Djb0501

Post Number: 73
Registered: Jul-07
Troy, I know they're SPL subs, but how do they sound? Do they hit the low notes well? How would you rate the overall quality of the BTLs?

I'm in the process of tracking someone with a pair of them down so that I can actually hear them, because up to this point I've only seen pictures and video

Thanks a lot for the pics and video by the way. That looks like you put a ton of work into it and I'm sure it sounds awesome
 

Gold Member
Username: Tejcurrent

Post Number: 2264
Registered: Apr-07
It sounded pretty good. Unfortunately I took it out and sold everything.
My best score with those subs at a competition was 153.4 db at 32 hz. That should tell you something about the lows when I know I had at least another db or 2 at that frequency if I fixed my voltage issues and turned the amps up. It sounded pretty good on the low end, but needed a TON more work on the front stage for things to sound right.

The BTLs were great subs, they handle a good bit of power and sound pretty good. There are better sounding subs out there, but I wouldn't hesitate to own another.
 

Gold Member
Username: Tejcurrent

Post Number: 2265
Registered: Apr-07
Deathoob, I'm still working on the dual 21 setup. I need time and money to get the alt bracket made and I don't have enough of either right now. I painted the dash bezel but wasn't happy with how it turned out- tried to repaint today and the damn humidity orange-peeled the crap out of it
I'm just going to buy another if I can find it for less than 100 bucks.

I'm having trouble finding some of my music with good bass, but I did as good a bag-trick yesterday with the wardens as I did with the btls. I really think I'll be pretty close on the meter when it's all said and done.
Depending on how things play out I MAY be able to meter Saturday, otherwise I'll be buying a termlab soon.
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