12" L7 in a single cab truck

[davidt487 10+ year member]

im not telling you to tune lower keep your tuning frequency but add port area

25 to 30 sq in would be my min for a box that size but to keep your current tuning freq you will have to lengthen your port

 

[joe98chevy 10+ year member]

I hear ya. Mine didn't originally but I plundered a 95 suburban for a pair at a local wrecking yard.

i was thinking of doing the same months ago but now i just want to sell the truck and get a tahoe. i need room for some 15z lol //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Criostior 10+ year member]

im not telling you to tune lower keep your tuning frequency but add port area 25 to 30 sq in would be my min for a box that size but to keep your current tuning freq you will have to lengthen your port

Im not sure Im following you. At 10*1*8 the port is covering 80 sq in. are you talking about the side (1in height part) needing to cover the 25 mark, and not the bottom (8 in wide part)?

 

[PrestigeSounds 10+ year member]

bring it up to 2...

 

[SubNit 10+ year member]

I see standing waves in your future with that design.

I hope you know what kind of sound you'll achieve with that space/port combination. After working with L7's myself I can tell you they usually sound like shit with small ports

 

[davidt487 10+ year member]

you dont multiply all 3 measurements in calculating port area just the 10X1 which means you have 10 sq inches of port

if you make the port 10X3 you would have 30 sq in but you port is going to be a lot longer taking up a lot of you vol the sub will be using

 

[davidt487 10+ year member]

right now if you have a box vol of 3 cu ft with that 10X1X8 port would give you an tuning freq of 29 to 30 hz

to keep that tuning you with a port 10X2.5 the length would be 22 inches.

 

[Criostior 10+ year member]

I see standing waves in your future with that design.

would you care to elaborate on where you see the problem coming from?

you dont multiply all 3 measurements in calculating port area just the 10X1 which means you have 10 sq inches of port if you make the port 10X3 you would have 30 sq in but you port is going to be a lot longer taking up a lot of you vol the sub will be using

I follow you now. I'm learning ported boxes as I go here. =)

So after some playing around with numbers I can get 27 sq in port by going to a 13.5" (box width) X 2" port (comes out to 25.5 in long) and keep myself at 2.7 cu. ft. Well within Kicker specs, and from the consensus here a much better choice for sound.

 

[mxer69 10+ year member]

You should do this design for a real sub //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

I really like your design just hate to see it go to waste on that sub :/

 

[Criostior 10+ year member]

You should do this design for a real sub //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif
I really like your design just hate to see it go to waste on that sub :/

What is so wrong with the L7?

 

[davidt487 10+ year member]

i think you port is going to diplace more volume than .2 cu ft just the port will displace .4 plus the wood that makes the port.

have you modeled the l7 in win isd to see what kind of box you should be using??

 

[Slo_Ride 5,000+ posts]

Ive heard plenty of L7s that sound fairly decent. Hell I've heard Solo X's with decent sq. I hate when people say a certain sub will sound like crap, ANY sub can sound like shit. Work on your port, make sure its not to small (height need to be more than 1"), and you will be impressed with a 12' L7 in a single cab truck.

 

[Criostior 10+ year member]

Your correct on the larger displacement (its actually closer to .5 including the mdf). I was able to do a more precise volume calculation by having a friend of mine import my model into cad and have it calculate for me. The actual displacement of the box is 3.2 before port but including driver. That is how I got the 2.7 number.

As far as the winisd I cant find all the parameters it wants for the driver. This is what I came up with with the info in the manual.

Driver : L7

Vas : 2.2

Qts : 0.51

Fs : 34.00

SPL : 0.00

--

Project by : Criostior

Project for : you

--

Number of drivers : 1

Box type : Vented

Box size : 76.5 l

Tuning frequency : 30.00 Hz

Vent : 1 vent(s)

0.602 m length for each

0.343 x 0.051 m rectangle

Relative

Freq Gain SPL

[Hz] [dB] [dB]

20.00 -13.64 -13.64

25.00 -2.40 -2.40

30.00 9.00 9.00

35.00 4.96 4.96

40.00 2.40 2.40

45.00 1.28 1.28

50.00 0.72 0.72

55.00 0.42 0.42

60.00 0.24 0.24

65.00 0.13 0.13

70.00 0.07 0.07

75.00 0.03 0.03

80.00 0.00 0.00

85.00 -0.02 -0.02

90.00 -0.03 -0.03

95.00 -0.03 -0.03

100.00 -0.04 -0.04

 

[davidt487 10+ year member]

if im reading that right you have a 9 db peak at 30 hz then at 25 it drops to -2 that is gonna sound boomy. factor in cabin gain and its gonna make it worse but who knows try it if you dont like it scrap it and start over

ps if you just used a bunch of random numbers in winisd then you my not see these results anyway

try the online version of isd with those number and see what it looks like