(1) 18" Fi BTL vs (2) 15" Fi Q's *PICS*

[SHiZNiLTi 10+ year member]

I currently have a fully loaded 18" BTL getiing 2250rms in 6.7 cubes @ 31hz with 100sq.in of port, in the below pic thats not how I have the box positioned in my truck, I lay it down flat and either have the sub and port facing forwards or to the rear of the hatch....

With using the same 2250rms amp my 12" Type R's in 5 cubes @ 34hz actually hit the lows a little better with more authority and sounded better to the ear, but they don't even come close to being as loud as the BTL around the 37-45hz range...

So my plans are to build a new box for my 18" BTL to help bring out the lows, I plan on going from 6.7 cubes to 8 cubes while having it tuned to 30hz with 110sq.in.of port. The box will be CRX style with sup up and port back.

If this new box doesnt give me what I'm looking for I may sell the BTL and both Box's after I paint them gloss black and buy a couple of 15" Fi Q's and put them in 8 cubes at 30hz while using the same amp to power them.

Has anyone heard the Q's and a BTL in the same vehicle? Do you think the Q's will really be that much better then the BTL when it comes to hitting the 30-35hz range?

Please give me some advice, thanks!

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[Erthshker 10+ year member]

Ive heard from sum Q owners tht they arent the best @ picking up the lows....if u decide to sell the BTL let me know im lookin for one...

 

[duece212 5,000+ posts]

From the great 12" challenge it looked like the btl hung in great with the others down low. You think with that motor/suspension, and the mass of the 18" cone you may need more amp to get it moving better down low? Just a thought.

 

[dvrmstrng 5,000+ posts]

my 18" Q in 9.3 cubes tuned to 28htz hit the lows prettttty well

 

[SHiZNiLTi 10+ year member]

From the great 12" challenge it looked like the btl hung in great with the others down low. You think with that motor/suspension, and the mass of the 18" cone you may need more amp to get it moving better down low? Just a thought.

That could be the case, but very odd though that 2250rms wouldnt be enough power, but it does make some sense. The sub does have alot more excursion on the 35hz - 38hz test tones then it does on the 30hz - 34hz test tones. Don't get me wrong though, the sub is still moving alot of air at a 30hz test tone, but it just doesnt have that thunderous deep sound. I'll try t make some vids of different tones this weekend.

I also read the Loyd review on 12's, the BTL sure did keep up, I wonder if there is a big difference between the 12 and the 18 in regards to hitting the low?

my 18" Q in 9.3 cubes tuned to 28htz hit the lows prettttty well

Ya I saw that box, it was huge. It's kinda funny we are doing the opposite thing. You went from 9.3 cubes to 6.5 cubes and Im going from 6.7 cubes to 8 cubes. How do the lows sound now in your new box? Can you explain the differences of output, SQ and ability to hit low notes between the two?

Anyone else have any opinions on the Q's or input on re-designing my current box that the BTL is in?

Can increasing the size of the box from 6.7 to 8.0 really make the lows come to life that much?

 

[duece212 5,000+ posts]

increasing the size of the box will make it more efficient (easier to drive down low) I'd ask over on SSA and see what they say.

The 18 has more mass to move than the 12 from the challenge so like power may not get the same end to end results (kind of why sometimes people with low power get less spiders on the MT18's).

Go on SSA and ask the man that makes the moofers //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

ohh...Also naturally your gonna get less cone movement at your 30 to 34hz because its closer to your boxes tuning freq...more control there.

 

[Mugen 10+ year member]

Why don't you just tune lower? Bigger box + 28hz = loooow

 

[15nissen 10+ year member]

that because your box is wrong. sub up port back. try aeros, then you plug a port to tune lower etc.....its alot easier. aeros = wang

and BTW, your not giving it nearly the power that you think. mo power may help as well.

 

[SHiZNiLTi 10+ year member]

increasing the size of the box will make it more efficient (easier to drive down low) I'd ask over on SSA and see what they say.
The 18 has more mass to move than the 12 from the challenge so like power may not get the same end to end results (kind of why sometimes people with low power get less spiders on the MT18's).

Go on SSA and ask the man that makes the moofers //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

ohh...Also naturally your gonna get less cone movement at your 30 to 34hz because its closer to your boxes tuning freq...more control there.

Makes sense, I'll do that.

Why don't you just tune lower? Bigger box + 28hz = loooow

True, bigger box is gonna be the way to go, phattony is making a giant box at 28hz, I'll see what results he gets.

I didn't want to go insainly low, I just want the BTL to sound up to par with how my old type R's did on the lows around 30-35hz. Remeber the Type R's were tuned at 34hz and the lows at 30-35hz sounded/felt more powerful and caused more flex at that tuning compared to my current tuning of 31hz for the BTL. when playing the same test tones.

In the above paragraph, my way of thinking is probably off. I guess you cant really compare different subs in the differently tuned box's. Every sub acts differently in the box taht its in. ... Look at the guy with the flex vid of the HD3 he is at 40hz, but has made flex at the lower 30-34 hz range.

 

[mazdakid 5,000+ posts]

have you tried putting your seats down and moving the box away from the back door at all? it looks like its about 2" away in the pic

 

[SHiZNiLTi 10+ year member]

have you tried putting your seats down and moving the box away from the back door at all? it looks like its about 2" away in the pic

Yes, I've tried about 8 different box positions. When my seats are folded down it gives me a huge area to work with in positioning of the box. In that 2nd pic that's the Type R box, the subs were facing the front of the vehicle not the back, when I have my box's face the rear hatch they have about 5" of room between the rear hatch and port.

 

[NDMstang65 10+ year member]

not to mention the low end will pick up once the suspension loosens up a bit, it takes a while

I beat on mine for 3-4 hours at 20hz free air with ~8-900w to get it to loosen up a smidge

 

[InsaneKreationz]

Thats not enough power for a BTL... Just hoping you realize that.

Friends got a tt2250... basicly the same amp. My Sundown 1500d was louder in 2 installs.

 

[SHiZNiLTi 10+ year member]

that because your box is wrong. sub up port back. try aeros, then you plug a port to tune lower etc.....its alot easier. aeros = wang
and BTW, your not giving it nearly the power that you think. mo power may help as well.

Yep, this is what I had planned for the next build, but raise it up a few more inches, It's 7.5 cubes @ 30 hz after sub displacement and 88.75 sq in of port, 37 width, 26 depth and 23 height. I could use aero's, it would be kinda like Baseballers (2) 18" BTL build then....

not to mention the low end will pick up once the suspension loosens up a bit, it takes a while
I beat on mine for 3-4 hours at 20hz free air with ~8-900w to get it to loosen up a smidge

The lowend is getting better day by day I can tell. thnx for info.

Thats not enough power for a BTL... Just hoping you realize that.
Friends got a tt2250... basicly the same amp. My Sundown 1500d was louder in 2 installs.

That's interesting.... To me it looks like the sub is at full excursion, It even bottom's it out in some song's if Im not carefull with the volume knob. The ssf is correctly set on it too, its not like im bottoming it out on a 20hz test tone with no ssf, this is just with jeezy music. Maybee his TT model is rated at a lower rms and my VX model puts out more since it's rated at 2257rms @ 1 ohm @ 13volts.

 

[15nissen 10+ year member]

if you never clamped the amp, you cant say its actual power. i would doubt its over 1500 rms.......is for the box, that other build you were talking about he didnt use areo ports. pvc doesnt count. buy 6 inch ports and it will wang if built right