New 18" Btl Problem

[greg662]

I have just ugraded my system from a 15" kicker L7 in a prefab box with a zx 1000.1 using a stock battery and alt. to a new 2008 18" BTL in a box built by WCCE wit a audioque 2200 and upgraded battery and alt. unless this sub really has to break in the L7 is louder. i have double checked everything and cant find that i have done anything wrong. the btl is louder with the highs but the L7 KILLS it with the lows.

the box specs are

24"H x 35"W x 20"D, 7.743^3ft gross vol. Slot port, 22.5" x 4" x 34.25 tuned to 34Hz

someone plz help me with this

[PaulO2288]

What was your other box tuned to for the L7? And is the AudioQue amp the same amp you used on the L7?

[audiofanaticz]

I have just ugraded my system from a 15" kicker L7 in a prefab box with a zx 1000.1 using a stock battery and alt. to a new 2008 18" BTL in a box built by WCCE wit a audioque 2200 and upgraded battery and alt. unless this sub really has to break in the L7 is louder. i have double checked everything and cant find that i have done anything wrong. the btl is louder with the highs but the L7 KILLS it with the lows.

the box specs are

24"H x 35"W x 20"D, 7.743^3ft gross vol. Slot port, 22.5" x 4" x 34.25 tuned to 34Hz

someone plz help me with this

your box is too way too big i think.

over 9 cubic feet if those are inside diameters, not including port or speaker displacement.

edit: I also think you got to much port volume.

[PaulO2288]

your box is too way too big i think.

over 9 cubic feet if those are inside diameters, not including port or speaker displacement.

Not too big. 7 cubes is fine. Even if the box is too big then it wuold still do good on the lows which is not doing, So I wouldent say its the box. If its a differnt amp, the subsonic filter maybe too high, or the tuneing of the box isent quite right. 7-8 cubes is around where hes at for an 18" is fine.

[audiofanaticz]

that big of a box is fine, for a spl setup. not for a daily driver. 5-6 cubes per 18 is sufficent.

[greg662]

no thats external. after all displacment its like 5.512 cubic feet. i have my sub sonic filter set to 10hz and my L7 box was tuned to 35 and i used a kicker zx1000.1

i am leaning towards the cd player or amp bc my amp gain has a 8v - .2v i have to but the gain on .2 bc as i turn it up the bass will slowly fade away to nothing at all when i get to 8v but then again i have never seen a gain like that.

also i have to put my bass on my cd player to 6+ and turn the loud on and turn the cd player up all the way up to get what bass i am getting now but even when i do that there is no clipping at all

[PaulO2288]

that big of a box is fine, for a spl setup. not for a daily driver. 5-6 cubes per 18 is sufficent.

You got it the opposite my friend. I use the same size box all around becaue my wattage dosent change from my daily driver to spl. Smaller boxes can handle more power. You still need enough box space for a sub. For an 18" I would suggest from 6-8 cubes after displacments. BTL18

DUAL 1 | DUAL 2

Fs: 00.0 Hz | 00.0 Hz

Re: 0.7 Ohms/coil | 1.5 Ohms/coil

Qms: 0.00 | 0.00

Qes: .00 | .00

Qts: .00 | .00

Mms: 000g | 000g

Cms: 0.00mm/N | 0.00mm/N

Sd: 1210cm^2 | 1210cm^2

Vas: 00.0 l | 00.0 l

Spl: 00.0dB 1W/1m | 00.0dB 1W/1m

Bl: 00.0 N/A | 00.0 N/A

Xmax: 16mm * | 16mm *

Rms: 2000W * | 2000W *

Sealed box: N/A cuft | N/A cuft

Ported box: 5-10cuft | 5-10cuft

Sub OD: 18.500” | 18.500”

Cut ID: 16.750” | 16.750”

Mounting depth: 9.750” * | 9.750” *

Displacement: 0.26cuft * | 0.26cuft

Any 18"s ive ran Ive always had around 7 bubic feet for each sub after displacments and the larger boxes always yeiled more bass and output even on the meter. I Also wasent running a lot of power. Just a hair over rms.

[greg662]

so you think its my box?

[PaulO2288]

What ohm is the amp running at and the sub? Im going to say the kicker was at 2 ohm. But are you getting full power out of your audioque at the 1 ohm? you may not be running it at that ohm

[audiofanaticz]

Just worked with some numbers a bit after knowing what the diminsions are giving.

If you used 3/4mdf the box is ruffly 8.06 cubed internally without port and sub displacement.

port displacement is 1.78 cubed

box with port displacement is 6.28 cubed. I dont know what the sub displacement is and if its a older or newer btl.

Displacement of a new btl is .26.

So your at 6.02 cubed with sub and port displacement.

Seems like 5-6 cubed is a great number to shoot for after displacements for a daily driver system.

and for the life of me I can not remember how to figure out how many square inches of port you have.

Turn the bass down on the headunit, bass all the way up and loud are just adding to distortion and clipping, and set your gains properly on the amp. if you got the gain on the amp turned to .02 your clipping the hell out of it! that is full gain.

What the gains mean, is if the dial is at 8volt, that means that it should be all the way down if you have a headunit that gives you a 8 volt preamp output. Try your gain at half which will be ruffly 4 volts.

What deck do you have?

The sub sonic filter is at 10hz, that is too low, and will just let the sub self destruct itself if you play some songs with low hz in them. turn it up to at least 20 hz.