Right, I'm going to attempt building my own sub box. I had thought about getting a car audio shop to build me one, but I was always pretty good at carpentry and it's not a complicated shape.

 

Because I have no audio engineering knowledge, I am at a bit of a stumbling block. Really need to know, in essence, what's the key to building something that not only looks good, but also does what it's supposed to and sounds good?

 

Not after a mega system as sounds offs or high street parading aren't really my thing. So a single sub box for my for my 10" pioneer and amp is pretty much all I am after.

 

I can't get the bass definition from my current speakers, even with sound deadening and new cabling. Quality is very good, but just can't get good bass. Not sure whether putting and amp on all 4 speakers would do anything as the Alpine headunit is quite a high output unit anyway.

 

Since the HU has an pre-out for a sub, I can use the headunit to power the mid-range and trebble from the speakers and the sub pre-out for the sub.

Thing to remember about the box is that it needs to be air tight. If you can get it the right internal dimensions all the better. The best way to get the box air tight is to glue the wood together and then silicon bead round the inside.

 

Good luck with it, I know youwill do a good job, you always do.

 

Darrell

I thought you always needed a vent tube?

I thought you always needed a vent tube?

 

i think iff its a sealed box then they push air from the top and vented push air from the bottom and out the vent Si;)

That doesn't make a lot of sense Bri. Sorry. :(

si, with the zed, theres not enough room to build a proper sized box to fit either the left or right side of the boot, so a ported box is out of the question. as darrell has said, you need to just make a box how you want it to look, but make sure its airtight, this would be sufficient for what you want it to do.;) HTH

I thought you always needed a vent tube?

 

No mine don't. Depends what size, type and function that you are going for.

 

It should still be air tight however so that any air comes out of the bass hole rather than leaks out elsewhere.

 

The idea of the box is to compress the air.

 

Do a google and I'm sure you will find lots about it.

 

Darrell

this is the one i had done ....

 

These are mine. Bit of a pitta to get the angles right etc but worth it in the end.

no ports / vents in ours

 

think it depends on what you want, what type of sub you have and what kind of sound you want whether you have venty things or not ...

Thanks guys! Darrel, that's similar to what I'm going to do.

 

Also, I think I'll modify my Bose speaker enclosures and seal them up completely and will remove the metal speaker frames in the doors and will gut some Bose speaker boxes, mod them to accept 15cm speakers and seal. Should get some more bass definition shouldn't you think?

...so why do some sub boxes contain ports then? Sorry, I'm a complete novice when it comes to ICE. Learning as I go.

...so why do some sub boxes contain ports then? Sorry, I'm a complete novice when it comes to ICE. Learning as I go.

 

this might help...

 

The simplest box type system is a sealed enclosure. Here a woofer is mounted in a completely sealed box that isolates the front and rear waves of the woofer.

 

Advantages of the sealed design include ease of assembly, more lenient box size requirements, excellent transient characteristics, high power handling, and a typically smaller enclosure.

 

Disadvantages are less efficiency (requires more amplifier power) than vented enclosures and less low bass as compared to a properly tuned vented enclosures ABOVE the port tuning frequency.

 

 

Ported (Vented) Enclosure

Vented enclosures are similar to a sealed enclosure in design except that they add a “port” that is a certain length and a certain area around. This port, usually a length of PVC pipe, is tuned to a certain frequency by variation in the two parameters of area and length. By adding this port, the rear wave of the cone motion is used to reinforce the front wave. When done properly the subwoofer system becomes more efficient than a comparable sealed enclosure ABOVE the port's tuning frequency. However, below the port tuning frequency the woofer will become unstable and "unload" causing the woofer to oscillate violently, leading to premature woofer failure when driven with excessive power.

 

Advantages of this design are increased efficiency and a lower frequency extension above the port tuning frequency.

 

Disadvantages are a more complex design, a larger enclosure as compared to a sealed design, lower power handling, and slightly less transient accuracy.

 

 

http://www.caraudiohelp.com/custom_car_audio_boxes/custom_car_audio_boxes.htm

if you only want to run mid & top end from your door & rears, then it wont make any difference sealing them. it would be a waste of time.

if you only want to run mid & top end from your door & rears, then it wont make any difference sealing them. it would be a waste of time.

 

I do, but I also want some more mid-range and low end base from them. Not much, but something better.

...so why do some sub boxes contain ports then? Sorry, I'm a complete novice when it comes to ICE. Learning as I go.

 

 

not sure if this may help you, or baffle you even more, but its worth a look http://www.eminence.com/resources/cabinets.asp

this might help...

 

The simplest box type system is a sealed enclosure. Here a woofer is mounted in a completely sealed box that isolates the front and rear waves of the woofer.

 

Advantages of the sealed design include ease of assembly, more lenient box size requirements, excellent transient characteristics, high power handling, and a typically smaller enclosure.

 

Disadvantages are less efficiency (requires more amplifier power) than vented enclosures and less low bass as compared to a properly tuned vented enclosures ABOVE the port tuning frequency.

 

 

Ported (Vented) Enclosure

Vented enclosures are similar to a sealed enclosure in design except that they add a “port” that is a certain length and a certain area around. This port, usually a length of PVC pipe, is tuned to a certain frequency by variation in the two parameters of area and length. By adding this port, the rear wave of the cone motion is used to reinforce the front wave. When done properly the subwoofer system becomes more efficient than a comparable sealed enclosure ABOVE the port's tuning frequency. However, below the port tuning frequency the woofer will become unstable and "unload" causing the woofer to oscillate violently, leading to premature woofer failure when driven with excessive power.

 

Advantages of this design are increased efficiency and a lower frequency extension above the port tuning frequency.

 

Disadvantages are a more complex design, a larger enclosure as compared to a sealed design, lower power handling, and slightly less transient accuracy.

 

 

http://www.caraudiohelp.com/custom_car_audio_boxes/custom_car_audio_boxes.htm

 

 

Thanks Athene, that kinda clears that up. For a more basic system, I guess I'll be fine with a simple sealed unit.

I do, but I also want some more mid-range and low end base from them. Not much, but something better.

 

you would never hear the low end bass from them as the sub would overpower them. ive kitted out many competition cars in the past so this is nothing new to me :D

So running my 4 speakers from the headunit, powering trebble and lame mid-range (bass turned down low), with the amp being powered from the sub-woofer pre-out to a sealed box should be exactly what I need?

If you really want to get into it try looking at this.

 

http://spkrbox1.spaces.live.com/

 

Darrell

Si, you need to read up on the specifications for the Subwoofer you have. It will tell you the recommended Enclosure size and wether its recommended for a sealed or ported enclosure or either.

 

Typically a 10" subwoofer requires an enclosure with 1 to 1.5 cubic feet of internal volume for optimum performance.

 

Sealed boxes tend to be smaller than ported, and therefore betters suited for the space constraints of the 300zx boot.

So running my 4 speakers from the headunit, powering trebble and lame mid-range (bass turned down low), with the amp being powered from the sub-woofer pre-out to a sealed box should be exactly what I need?

 

 

yes, you got it ;)

it is also important to make all the dimensions of the box different as this helps stop internal reflections building up into nasty sounding vibrations, so dont build a cube, build a rectangle. also sloping sides will help.

 

make sure you include some acoustic wadding / damping inside the box (sort of like a nylon sheep) or some sound deadaning stuff as this will also help stop reverberation

 

as legrath said, important to check the recomended volume for your speaker or it wont sound as good as it should

 

make sure the speaker is fixed firmly to the box

 

fix the box to the car (no point in the speaker staying still and the box mooving

 

use some decent wood

 

maybe some internal bracing to make the box rigid

Thanks guys. I'll come up with a few designs over the weekend and will get the spec for the subwoofer. It's all written down on the box which is down in the garage. I'll post that up tomorrow and see what you guys think.

 

I am thinking of having a square type box which contours the top the boot line with the sub placed vertically so that it points inward. Kinda like a wedge of cheese. It'll be carpeted black, so will match the rest of the boot trim. I want to mount the amp underneath it as I want it all enclosed and out of the way, obviously making sure the amp has good ventilation. So need to make the enclosure so that it enables storage of the amp.

as legrath said, important to check the recomended volume for your speaker or it wont sound as good as it should

 

 

like i said in a previous post, theres not enough room on either side to do this :D

 

 

 

use some decent wood maybe some internal bracing to make the box rigid

 

ive always used 19mm mdf, screwed & glued. never had any problems with it yet.

Si See mine at japfest.

I have designed and manufactured a lot of pro cabs over the years for the pa company I use to run.

The infanate baffel is the only option for the zed due to the confinds of the boot area.

I will talk to you about cab design on sunday

I would also recomend you have an amp to run the mid hi speakers too.

 

Allan