Subwoofer in my car. Problem with it?

[Demonhax]

Evening.

So me and some friends found out that we had two 12'' subwoofers laying around, and decided to build a case for them and try them in my car. 

I original have one 10'' subwoofer in the car. 

We found some junk to build the case with. It's a pretty shitty case. we know. I'll add some pictures of the one we build and the old one i have in my car. 

But ones we were done building and mounting the subwoofers in the case we tried it. We were pretty disappointed with the result of the bass. 

My single 10'' where hitting harder and better then the two 12''. I think the single 10'' even went lower then the two 12'' did. Does anyone know why? Is the 12'' just plain and simple bad or old? or is the case that bad? 

[Rorgash]

its called quality difference most likely, also there are TONS of physics involved in a box for a speaker, and just because its 12 instead of 10 doesnt mean the watts are higher aswell, also they could be harder to drive and your amp isnt powerful enough, soo many reasons for this its not possible for me to figure out

[Dave :)]

Did you properly seal the box? One of the reasons you need a sub box is to provide that low-end 'punch'..this is achieved by a properly sealed enclosure (you can have ported boxes which produce a slightly different sound but that's beside the point). From your pictures it looks like you have just nailed a couple bits of wood together, this is going to allow air to leave and not produce a deep bass sound you desire.

 

If it isn't sealed, I would take the box apart, use glue, screws and a silicone sealant on the inside. 

[Demonhax]

its called quality difference most likely, also there are TONS of physics involved in a box for a speaker, and just because its 12 instead of 10 doesnt mean the watts are higher aswell, also they could be harder to drive and your amp isnt powerful enough, soo many reasons for this its not possible for me to figure out

Ah, but for me that dont know shit about this. it sounds wierd that two 12'' dosnt hit harder then a single 10'' This is the amp i have. http://www.parts-express.com/mtx-thunder-ta7804-4x200w-super-amplifier--267-032.

 

[Demonhax]

Did you properly seal the box? One of the reasons you need a sub box is to provide that low-end 'punch'..this is achieved by a properly sealed enclosure (you can have ported boxes which produce a slightly different sound but that's beside the point). From your pictures it looks like you have just nailed a couple bits of wood together, this is going to allow air to leave and not produce a deep bass sound you desire.

 

If it isn't sealed, I would take the box apart, use glue, screws and a silicone sealant on the inside. 

Well, i can't say we properly sealed it. We did just nail them together. But if we were going to build a new box would u suggest a air hole? or should we just make a totaly sealed box?

[TheMastr13]

Make sure your amp has enough power to properly drive the subwoofers

[Dave :)]

Well, i can't say we properly sealed it. We did just nail them together. But if we were going to build a new box would u suggest a air hole? or should we just make a totaly sealed box?

 

I'd suggest a standard sealed box. Just so you know it works. Here's a decent guide on the process involved in making a box 

[Demonhax]

I'd suggest a standard sealed box. Just so you know it works. Here's a decent guide on the process involved in making a box

So something like this would be too "risky" to make?

[Dave :)]

So something like this would be too "risky" to make?

 

I guess it depends on how handy with the tools you are haha.

[Demonhax]

I guess it depends on how handy with the tools you are haha.

Haha yee, guess so.

But will it work u think? Cause i can see that one got a bit of air vent

[Dave :)]

Haha yee, guess so.

But will it work u think? Cause i can see that one got a bit of air vent

 

It's more complex to make and I don't know exactly how it all works to be perfectly honest. If i were you, I would just stick to making a basic sealed enclosure as that just requires sealant and you don't have to deal with this "ported" business. 

[Lutkeveld]

Which model are those subs? Get the Thiele/Small Parameters if you can, I'll model a box for you. If it works better sealed or ported depends on the parameters.

 

For the box: use a lot of wood glue and thick MDF.

[Demonhax]

Which model are those subs? Get the Thiele/Small Parameters if you can, I'll model a box for you. If it works better sealed or ported depends on the

parameters.

For the box: use a lot of wood glue and thick MDF.

It would be great if u could model a box! I didnt find so much specs for them. But think i found the right model. Zachry BX-S12

[Lutkeveld]

@Demonhax

I found the Thiele Small Parameters:

Qts = 0.54

Vas = 50.8L

Fs=39Hz

 

I've loaded them in to WinISD to simulate their acoustic behaviour.

They need a lot of space. You can go with 60 liter sealed or 200L vented (assuming you use 2 drivers)

Closed will reach to 56Hz, vented to 27Hz (both excluding room/cabine gain)

[Demonhax]

@Demonhax

I found the Thiele Small Parameters:

Qts = 0.54

Vas = 50.8L

Fs=39Hz

I've loaded them in to WinISD to simulate their acoustic behaviour.

They need a lot of space. You can go with 60 liter sealed or 200L vented (assuming you use 2 drivers)

Closed will reach to 56Hz, vented to 27Hz (both excluding room/cabine gain)

I found out that i can only use 1 of the 2 i have. the other one was broken. so what if i were to onlý use the one 12?

[Lutkeveld]

Then you only need half the airspace

[Demonhax]

Then you only need half the airspace

Sweet! Thanks alot!

[Lutkeveld]

If you need vent dimensions; let me know. If you go with sealed; just make sure the airspace is 30-40 liters.

 

If you need a cutting plan for the (at least 3/4" MDF) wood, let me know too

[ManWithBeard1990]

Building a perfectly sealed box would be easiest. Something with a bass port may get louder but it's harder to get the sound right.

[Lutkeveld]

@ManWithBeard1990

We have the Thiele Small Parameters so it's not that difficult to get the sound 'right'. 

I've simulated the sub in WinISD and could give OP the 'right' port dimensions.

I say 'right' because there is no real right port dimension, it depends on the tuning frequency.

 

Ported cabinets go deeper, not louder. Unless you tune them too high and create a bump in the response.

[ManWithBeard1990]

@ManWithBeard1990

We have the Thiele Small Parameters so it's not that difficult to get the sound 'right'. 

I've simulated the sub in WinISD and could give OP the 'right' port dimensions.

I say 'right' because there is no real right port dimension, it depends on the tuning frequency.

 

Ported cabinets go deeper, not louder. Unless you tune them too high and create a bump in the response.

Didn't actually know that. Thanks mate. I'd have to look that up.

[Demonhax]

If you need vent dimensions; let me know. If you go with sealed; just make sure the airspace is 30-40 liters.

 

If you need a cutting plan for the (at least 3/4" MDF) wood, let me know too

I was think about a sealed box, but i found out that if i have a vent the air pressure makes a type of bass sound itself. (I think) I kinda wanted to make a box that looks like this. https://gyazo.com/56fdbde395833dfba67df59676446600 If possible

[Lutkeveld]

A port extends the response by resonating at frequency the sub normally can't reproduce.

As said, the port gives almost an octave extra extension, from 50 something to 20 something hertz.

Of course everything has its price, in this case a larger enclosure.

[Demonhax]

A port extends the response by resonating at frequency the sub normally can't reproduce.

As said, the port gives almost an octave extra extension, from 50 something to 20 something hertz.

Of course everything has its price, in this case a larger enclosure.

Ah, okey. but if i were to make a bigger box for the sub (100l) would this designe be something worth trying? https://gyazo.com/56...67df59676446600

[Lutkeveld]

@Demonhax Yeah that's fine. You can use that type of box / port. 

Exact dimensions depend on the sub being used and the tuning frequency.

If you're sure that you want to go ported (so that I'm not wasting time) I could make a cutting plan for you.

Do you prefer deep, flat or boomy?