Subwoofer Tuning Question...

[Chris C.]

Okay, so I have 2 12" L7's in a bandpass box. I have the kicker sx1250.1 amp pushing them.
No doubt the subs are loud, but I don't think there tuned correctly. I really want to take advantage of the amps DSP abilities.
Inside the car it is "loud". but outside, you don't get the feeling deep in your chest,:D. I know the subs are capable of hitting lower frequencys. is it possible to do with my setup, or am I aiming to high?

I'm sure you'll read this NoTLaDStyle, and I know square subs arent your thing, but could you help me out?

[Notladstyle]

Okay, so I have 2 12" L7's in a bandpass box. I have the kicker sx1250.1 amp pushing them.
No doubt the subs are loud, but I don't think there tuned correctly. I really want to take advantage of the amps DSP abilities.
Inside the car it is "loud". but outside, you don't get the feeling deep in your chest,:D. I know the subs are capable of hitting lower frequencys. is it possible to do with my setup, or am I aiming to high?

I'm sure you'll read this NoTLaDStyle, and I know square subs arent your thing, but could you help me out?

What are the specs on the bandpass box(if you know)? Did you have it custom built? What kind of vehicle do you have them in?

You don't need, and generally shouldnt use any DSP or sound EQs except to tweak already good sound. If you arent happy with the bass, I would try re-orienting the box first(change the direction it faces/turn to the side etc..), then consider building a new box for them.

For LOUD low end I would go with a ported box. Every prefab box I found for the L7 was tuned to 38hz and had volume about 1.75 - 2.0 ft^3 per chamber. For some reason I'm just feeling that a ~2.5 - 3.25 ft^3 tuned to 33hz would give you closer to what you are looking for. The bigger the box the better. But bandpass is not the way to go for serious output.

I haven't built a box as large as what you will need to get the bass you want. I would want to give that a try just to see what kind of thunder it puts out. John probably has though, lets see what he thinks...

[Chris C.]

What are the specs on the bandpass box(if you know)? Did you have it custom built? What kind of vehicle do you have them in?

You don't need, and generally shouldnt use any DSP or sound EQs except to tweak already good sound. If you arent happy with the bass, I would try re-orienting the box first(change the direction it faces/turn to the side etc..), then consider building a new box for them.

For LOUD low end I would go with a ported box. Every prefab box I found for the L7 was tuned to 38hz and had volume about 1.75 - 2.0 ft^3 per chamber. For some reason I'm just feeling that a ~2.5 - 3.25 ft^3 tuned to 33hz would give you closer to what you are looking for. The bigger the box the better. But bandpass is not the way to go for serious output.

I haven't built a box as large as what you will need to get the bass you want. I would want to give that a try just to see what kind of thunder it puts out. John probably has though, lets see what he thinks...


Yes the box is custom built. Moe at State of the Art Customs designed and built it for me. Unfortunately, he has lost the disk with the spec's. :(
I will try to get them up tonite. They were installed in my 02 Sentra. We had to remove the Rockford Sub, :). I can tell you now that the box is huge, it does not leave any room, and the sentra's trunk is not that small.

I had the vent facing towards the cabin, but I turned them towards the trunk so I could get better SQ. And yes, it is lined with Dynomat. :) I know you have ports in your rear deck, would you recommend this for me?

[GradeA_TireFryer]

Notladstlyer Is Correct, The Larger The Box Volume The Lower/louder It Will Be
The Advantage Of A Bandpass Box Is You Get 2 Tunes, Hi Pass(normally Sealed Section) And Low Pass (ported Section)
A Bandpass Box Normally Allows The Sub To Handle More Power

[Chris C.]

This is actually a vented bandpass box. At least thats what SAC said. I was always under the impression a vented box and a ported box are not the same.

[GradeA_TireFryer]

Ported Box - See Speaker And Port/vent Move Air
Single Reflex Bandpass - Do Not See Speaker - One Side Speaker In Sealed /other Is Ported/vented

Double Reflex Bandpass- Do Not See Speaker - One Side Speaker In Ported/vented Tuned /other Is Ported/venteddifferent Tuned

[Chris C.]

http://www.tamparacing.com/photopost/data/500/medium/PA260013.JPG



And there are no other ports or vents....

[Notladstyle]

eww, that box is teh ugly and not good for low, ground shaking bass. its not big enuff either for two. go back and get him to throw you together a giant simple vented box tuned really low. Fuck SQ, you bought square subs, you want BASS.

double reflex boxes are good for only a very narraw aplication, unless you built it exactly to your tastes its not the best choice. A ported box will let you pull out all the lows you want, and will be louder than what you have now.

Yes two really giant ports into your cabin might enhance the bass output but that would be a trying task to port something of that magnetude into your car and still have it be decent looking - perhaps take out the 6.5" speakers and use the holes as inlets? My Diamond 12" has three 1.5" ports - very easy to port. Plus, with that much power the difference in sound will be minimal ~5db

[Chris C.]

aww, come on, she ain't that ugly! :)

Is there any way of just modding the box? Maybe seal the front vent, remove the two vent dividers, and porting the sides?

About removing the rear speakers, can you elaborate more on this? Do I just remove the speakers and keep the speaker grill there? Or is there another way I could do it?
And when you say a ~5db sound difference, is this a good thing or a bad thing?


P.S.- You will be getting rep points for this once TR lets me. It seems I have been too generous in the last 24 hours. :)


This is a pic of how the subs were before. I have now reversed the box so the vent is facing the license plate.

[TBSpyder]

I personally would never use a bandpass box. You'll get it tuned alright for one song, and it's just going to sound like shit on another. IMO, there's way too many variables in music to use a box designed to hammer at a specific frequency. Not to mention I've yet to hear a bandpass box that wasn't muddy.

[djgizmo]

aww, come on, she ain't that ugly! :)


Yes, she is. Have it re-carpeted.

Also, whats with needing to have it loud OUTSIDE your car? Don't you listen to the music on the INSIDE. When I in a vehicle, I want to hear / feel the bass. I wanna have my chest hurts INSIDE the car. Rattling a neighbors house or shaking the crap out of your license plate gets old, plus it smells of low class.



You're going to hear all kinds of advice. MOST of it is based on personal experience / opinion.

A bigger box does NOT always equal louder. In most cases it just gives you a tad bit more lower end.

I'm more into SQ anyday. I've heard some of the cleanest, and some of the loudest systems. All of them used sealed enclosures.

Each enclosure type has its advantages / disadvantages.

Sealed:
PRO:Great for cone control and SQ (only 1 sound wave), if you have the proper amp running it. Smaller Enclosers, Decent amount of cone control.
CON: Not enough power will cause the sub to seem weak and even low quality.

Ported (Vented):
PRO: Give a boost in SPL since both the front wave and back wave are be projected. (Front Wave from the cone, back wave out of the port), Requires less power to sound as loud.
CON: Larger Enclosures (usually much larger), Lower SQ due to both waves being heard causing collision of reverse waves, Less Control due to the less resistance to move air in 2 directions (IE, can blow a sub ezier because you can push it physically farther).

Bandpass: Come in 2 different flavors... Single and Double Reflex.
Single: Simple Concept. Sealed Box inside a ported box. ([O]=) - One port on the outside of the box that allows air to flow from the cone.
PRO: More cone control than a ported box, but requires more power than a ported box. Good for SUV's and Vans. Can sound good if used in the proper application.
CON: Can get muddy if port tuned to low or too high.

Double: Simple Concept. Ported inside another ported box. (=[=O]=) - One port on the outside of the box that allows air to flow from the cone and another port from the back wave of the sub to the outside of the box. Typically tuned different.
PRO: Less cone control than a single ported box, requires less power than a single box, Good for Home Systems.
CON: Gets muddy real quick. I don't like them because SQ generally suck.

ISOBarric (sp?)
2 Woofers in 1 enclosure with the cones facing each other and wired inversely. (1 is Neg to Positive) This is usually used for SQ only applications since this has the most cone control.
CON: Low SPL with small drivers and power.

[Chris C.]

Yes, she is. Have it re-carpeted.

Also, whats with needing to have it loud OUTSIDE your car? Don't you listen to the music on the INSIDE. When I in a vehicle, I want to hear / feel the bass. I wanna have my chest hurts INSIDE the car. Rattling a neighbors house or shaking the crap out of your license plate gets old, plus it smells of low class.



Yea, I guess the carpet does suck... :(
Anyway, thats what I meant to say. Of course I listen too it in my car. But I don't get that feeling in my chest. I just get a shitload of vibration. I thought the dynomat would help with this.

[djgizmo]

Dynomat does help, just stops the cabin chasis vibration. You need to find out where the vibrations are coming from. Common places are the trunk lid, license plate, main exhaust pipe near the cat, and inside the doors.
If you want more hurt for your buck, you need to find out what you want then go get it. Do you want low rolling bass, or hard hitting kick drums? If you want more rolling bass, ported should do what you want, but be carefull not to over power your subs. The amp's RMS rating should not exceed the subs Max rating.

I would suggest selling the box if you have a car (not a SUV / VAN). The only reason I recommend that is that you want to feel it in your chest, and unless that port loaded thru your back deck (IE basically your back deck becomes apart of the subwoofer box), the loss of energy to the cabin in 2-3x as much as a normal ported box or sealed box.

[Notladstyle]

That chest feeling will only come from a VERY small sealed box(reduced output) or a properly tuned/built vented box tuned to the lower end. I promise you will be 110% happy if you just go get that box rebuilt

[Rhino236]

why is every one copying and pasting from the internet?? Get a huge vented/ported box facing towards the trunk and get it tuned to like 30-40 hz,and it will be loud as hell(i have someone who could build you a god ass box if u needed),also check the low pass frequency on your amplifer that will affect the lower bass also,shhot me a pm if u need to

[Chris C.]

Okay, I'm not a complete newb, but when it comes to building enclosure's I am lost. When you say "get it tuned", what or how do you accomplish that?

Don't get me wrong, the box is nice, and puts out some noise. It is professionaly built, but i realize it isnt made for the application I was looking for. I put some big $$ down on the box, and I hate to see it go to waste.

Like I said before, could I just modify my current box? IE, seal the Vent and port the sides?? I really have no clue with box design or box tuning.

[TBSpyder]

Dynomat does help, just stops the cabin chasis vibration.

Huh?


The amp's RMS rating should not exceed the subs Max rating.

Yeah, um, no.


I would suggest selling the box if you have a car (not a SUV / VAN). The only reason I recommend that is that you want to feel it in your chest, and unless that port loaded thru your back deck (IE basically your back deck becomes apart of the subwoofer box), the loss of energy to the cabin in 2-3x as much as a normal ported box or sealed box.

Wha-huh? Ya-no.


Some of you newbies around here need to do some research before making posts. Spitting out a bunch of bs is only going to make these people asking the questions more confused. No info is better than bad info.

[Chris C.]

Thanx, John, I like Straight forward answers.

[Notladstyle]

You cant just plug a port into it, you need precise measurements of volume, port length, resonant freq in your vehicle, native curve of yoru vehicle, and tuning freq and the the Thiele parameters for the subs.

You dont have to trash the box, go back and tell them to rebuild the thing as a sinple vented box. OR just build another one and keep that one for later! its so fucking cheap you have nothin to lose except more time wasted with sound you dont like.

+1 to tbspyder xcept the deck porting, it can make a serious difference but I didnt understand what that post was saying either.

[Chris C.]

You cant just plug a port into it, you need precise measurements of volume, port length, resonant freq in your vehicle, native curve of yoru vehicle, and tuning freq and the the Thiele parameters for the subs.

You dont have to trash the box, go back and tell them to rebuild the thing as a sinple vented box. OR just build another one and keep that one for later! its so fucking cheap you have nothin to lose except more time wasted with sound you dont like.


Its like I said, when it comes to box construction, I dont even know where to start. But, and Im sorry to keep sounding stupid, I thought I have a vented box now? Plus, I don't think I will be able to walk in there and be like, "Will you rebuild my box?" Anyway, I think I would like to port my rear deck.

Thank you everybody for your advice!!