boxes and tuning? WTF?

deathcloud · Post by **deathcloud** » Wed Nov 18, 2009 7:40 pm

So with my new icon I am going to get. I am now going to do the box right this time... no more buying prefabbed boxes from best buy... So here is my question...

I tired googling wtf box tuning is and what it means and I couldn't find a viable source... I tried searching here and I couldn't find a good thread so many came up.

Now can someone either link me or explain really well wtf box tuning is for porting?

I read from Digital Designs website that going ported is the way to get more efficiency. Basically in terms of an engine it is like putting a turbo on your car. So I deff want to do a ported box.

Now for the icon 12 inch sub I read that it says 1.9 cu.ft. box @ 27-33hz

How can you tune a box? It doesn't have a crossover on it? I know I sound dumb but WTF? I know my amp has a crossover on it so does that mean I set it to somewhere between 27-33hz?

I basically want to be those cool kids that are able to say "Yea I have a box ported and tuned to 32hz"

So what do I have to do? Can someone get me on the right track? I am ready to give up and go sealed again... cuz it is easier but I want to learn the ways and try ported and tuned or whatever. Thanks guys

GX3 · Post by **GX3** » Wed Nov 18, 2009 8:18 pm

To tune a box all that is done by the size of the port. There isn't a one size fits all. The volume of the box has an effect on the size of your port to equal a specific Fz .............there is software out there for this some of it is even free. Every one remember BlauBox RIGHT

http://www.caraudiohelp.com/subwoofer_e ... ftware.htm

gridracer · Post by **gridracer** » Wed Nov 18, 2009 8:39 pm

I know a guy that can design you a ported box that really knows his shit for a few bucks. Let me know if you want to go that route.

audiophyle_247 · Post by **audiophyle_247** » Wed Nov 18, 2009 8:49 pm

gridracer wrote:I know a guy that can design you a ported box that really knows his shit for a few bucks. Let me know if you want to go that route.

So can I

I also build & ship boxes quite often too.

denim · Post by **denim** » Wed Nov 18, 2009 9:36 pm

If you have room, see if you can build or have built a 2.25 @ 29hz, you will love it.

deathcloud · Post by **deathcloud** » Thu Nov 19, 2009 5:45 am

2.25 @ 29hz. Hmmmm. Do you think that will fit in the trunk of a mazda 3?

And is 2.25 Huge? That sounds like a box for 2 subs! LOL.

I deff would want maybe someone on here with experience to build it for me and then ship it. I have no clue what to do.

shaheen · Post by **shaheen** » Thu Nov 19, 2009 7:00 am

If you give me the specs I can design you one as well.

There are some good sites which have loads of info on enclosures and stuff.

Check out the JL site and www.carstereo.com, under the how to

ChaosWarlord26 · Post by **ChaosWarlord26** » Thu Nov 19, 2009 7:17 am

Is your mazada 3 a trunk or hatch. Any box can be done. I am putting a 7 cube box behind the seat of my single cab dodge ram. Without sacrificing but maybe 3 inches of leg room.

deathcloud · Post by **deathcloud** » Thu Nov 19, 2009 7:50 am

My mazda is a sedan. Not the hatch. But yea i think the only thing i am worried about is actually fitting it through the gap.

Id rather just pay someone here to design and build it for me and all i would have to do is build it back up. Dunno if thats possible tho with a ported tho.

vwguy3 · Post by **vwguy3** » Fri Nov 20, 2009 5:55 pm

denim wrote:If you have room, see if you can build or have built a 2.25 @ 29hz, you will love it.

When you tell him to do that, and tune the box at 29hz is that where it will only play or will it play higher notes? Sorry I have been having these ?'s too.

Thanks
Justind

deathcloud · Post by **deathcloud** » Fri Nov 20, 2009 5:59 pm

I think so. I've seen people post that they have their box for example 2.25 @ 29hz have their sub LP frequency set to 80hz.

So it doesn't mean that it will only play 29hz and below. It will still play higher notes.

This is what I believe... I'm not 100 percent sure but its what I've read.

Post by **Bfowler** » Fri Nov 20, 2009 6:38 pm

yes, 29hz means it will have a certain db gain at 29, which will roll off to other frequencies

Post by **ttocs** » Fri Nov 20, 2009 7:12 pm

the box will play what ever signal you give it, but the speakers will now have a gain at the tuning freq. They can play higher, and lower, but they are tuned to play at that freq the loudest.

audiophyle_247 · Post by **audiophyle_247** » Fri Nov 20, 2009 8:10 pm

Generally a subwoofer will begin to bottom out easier for frequencies played below the ports tuned freq, and the freq roll off (like a crossover) is actually quite steep below the tuning freq, dropping output substantially.

A low tuning freq spreads the gain of a ported enclosure, giving a more natural sounding bass curve, while still offering quite a bit more bass than a sealed enclosure.

Ideally you should set the subsonic filter to just below the ports tuned freq to keep the sub from killing itself.

joyride · Post by **joyride** » Fri Nov 20, 2009 8:31 pm

audiophyle pretty much nauled it with that description, so I wont offer any more advice on that front.

I would say just to build it yourself! Its not hard, and you will learn. Check out http://www.linearteam.dk/ and download it. The program is totally free and des all the hard math work for you. Just plug in the T/S and it will graph the output curve so you can get an estimate on where you want to be (and compare output). It willl even give you port length/diameter to build it yourself.

Hell, even if you build it wrong, you will learn. Thats half hte fun of this hobby. That and playing with power tools...(I miss my RT40

)

deathcloud · Post by **deathcloud** » Sat Nov 21, 2009 6:54 am

Yea don't get me wrong, I like building stuff. However, I am in college and I have no tools. Just school supplies. That is all.

Or I would totally try it out and fuck shit up. However I don't have shit to even try it. So I will probably just end up having someone else do it I guess.

deathcloud · Post by **deathcloud** » Tue Nov 24, 2009 6:43 pm

Ok so I think that I am going to attempt to build my box.

My uncle who lives here does flooring and has tools/experience with wood working and stuff.

Also what he does have experience with is fiberglassing and also doing carbon fiber in the hull inside his jet ski to make it stronger. I was watching some videos of building fiber glassed boxes and it doesn't look that hard. I want to attempt this.

So help me out guys who have had experience...

The box I want to build is 2.25 cu ft. I want it tuned to 29 hz.

Can someone give me dimensions of the box and also the port?

Here are some specs of the sub to help out for the box specs.

Fs 29.9
Qms 5.87
Qes .45
Qts .42
Mms 212 g
Sd 480 cm^2
Vas 43.7 l
Bl 16.4
Spl 86.0 1W/1m
Xmax 20.5mm
Wattage: 1000RMS
Displacement: 0.16cuft

If someone could help me that would be great. I kind of just want a box that has the sub facing up to the trunk. And the slot on the bottom facing up to the trunk as well.

I hope this makes sense... Thanks guys. I ordered my 12inch Icon sub I am super happy but want this box to be perfect for the sub.

audiophyle_247 · Post by **audiophyle_247** » Thu Nov 26, 2009 2:53 pm

Google "port calculator", and punch in the box volume & desired tuning frequency. There ya go.

Woofer specs are not needed, you already know what air volume you want & a port calculator will tell you the size of port you need.

You can build a super long & skinny box, a perfectly square box, or a funky shaped box, and have the same volumes & port size. The only way to design the box is measuring your car & seeing what sizes you can get away with. keep in mind that the required volume DOES NOT INCLUDE the port space, & volume changes change port lengths needed, so if you neglect this & build a box with 2.25cuft & drop a big port in it, the actual tuned freq can be significantly higher than planed, resulting in a box that will sound NOTHING like you had designed for. (most often sounding like complete shiat)

Building the box is not the hard part, it is the designing & calculation of everything that takes the most time. (atleast for me, but I build rather proficiently)
Measure out the trunk space you have (max height, max width, max length), you cannot make the trunk wider or taller, so the only real measurement you can adjust is the length. Setup a drawing of the box at the length you would want, and calculate what its internal volume would be (dont forget to subtract wall thicknesses

) and see what you have.
This is a good starting place.
From there you need to plan around the sub displacement & port displacement, and see how much volume you have left. Adjust the length of the box to get the internal volume you need, without forgetting sub & port displacement.

Quick reminders,
As internal volume shrinks, port length gets longer.
As port length gets longer, you loose internal volume to the port. (anyone see a cycle here?)

Dont forget to measure the trunk opening too, because a perfect box wont do you any good if it cant fit into the vehicle. lol

audiophyle_247 · Post by **audiophyle_247** » Thu Nov 26, 2009 3:00 pm

Another note, building with fiberglass/CF is FAR harder than it looks, and always a PITA. Even for the pros who have years of experience, FG/CF will always be a PITA compared to wood.

deathcloud · Post by **deathcloud** » Thu Nov 26, 2009 3:22 pm

Yea I feel ya. I think I got extremely lucky. My uncles friend said he has a 4 x 8 ft sheet of birch that I can use. For FREE. And then he has the glue and nails.

Just wondering what a typical box build materials we need. Hopefully I am right.

Is it just:

nails and wood glue? Thats all it seems to consist of.

Then carpeting I know and my uncle does carpet for a living so that shouldn't be hard to do as well.

Is birch a good idea to go? Should I not do birch? What and where and how do I do the speaker connector? Do I just make small holes and run wire to the sub? Or something else to make it look professional. Let me know.

Post by **ttocs** » Thu Nov 26, 2009 5:21 pm

not sure how big the nails are, but you do not want anything bigger then a brad-style or you will run the risk of splitting the wood. Screws are a better way of doing it but it is more time consuming by the time you pre-drill and the tap the screw.

By birch, is it a plywood or is it more like baltic birch or mdf?

They make box terminal cups that can make the wiring to the outside easy and they are easily available online or possibly at a local car audio specialty store.

Unless the customer requested it, I would just drill a hole and poke the wire through. Tie a knot on the wire inside the box once the wire is through, then add some silicon or some type of sealer and put it in the hole. When you pull the knot so that it hits the wood, it will seal the box and keep it from being ripped out of the speaker.

Don't forget to put a bead of silicon along the inside edges to ensure that it is sealed properly.

FG is time consuming and messy by the time you figure in the sanding, filling, and some more sanding but it is not really all that big of a deal. The most important part is in the prep to make sure that you have everything ready and at arms reach when the kicker hits the resin or you will be making an even bigger mess. Once you do a couple of them it is almost easier then wood in alot of instances.

now getting CF to look good is the only hard part about it. Again it takes time, and alot of fine sanding....................

audiophyle_247 · Post by **audiophyle_247** » Thu Nov 26, 2009 6:18 pm

Generally I drill a small hole for the speaker wires and fill/seal the holes with a hot glue gun (+ very high temp glue). I just dont like to tie knots in wire wiring, and silicone is not very strong and can easily blow out over time.

I use wood glue, clamps, & an air nailer to put the box together. With quality tools & precise cuts, you dont need to silicone the joints inside the box. Dont forget about internal bracing, that Icon will really beat on a box and it has to be built stout, & I strongly recommend a double baffle.

How thick is the Birch? As long as it is a solid Birch & not a pressed plywood style, you should be okay. You will need a MINIMUM 3/4" wall thickness, and a good amount of bracing on any surface bigger than a square foot.

ttocs wrote: now getting CF to look good is the only hard part about it. Again it takes time, and alot of fine sanding....................

Working with CF is a huge pain. Getting it to look right without any irregularities in the pattern is harder than it sounds when you are wearing gloves with sticky shit on them. Grinding & sanding the large areas & actually cutting through the CF itself is a bitch because the dust can short out your power tools. The fine sanding required to level & polish the exterior sucks more than body repair, and if you sand through to the CF its easy to F up the weave, not to mention the risk of tiny bubbles in the resin, any tiny flaw will be very noticeable when its finished.

Post by **ttocs** » Fri Nov 27, 2009 7:14 am

I have never build a box with out putting a layer of some kind of sealer and I am always crazy with the wood glue. While it shouldn't be needed I have only really ever seen it missing in pre-fab boxes and never worked in a shop that didn't do it. These shops all had great table saws to make the cuts perfect but it has always been included in any box-building-maunal I have seen.

audiophyle_247 · Post by **audiophyle_247** » Fri Nov 27, 2009 10:38 am

precise cuts are important, but clamping the joints makes for an excellent connection and spreads the glue evenly. Also depends on the glue you use, for the love of god dont use liquid nail, atleast buy a decent wood glue.

I dont use any sealer because I know its not needed with my boxes, but a novice builder may not have the same level of trust in their builds and the little peace of mind the silicone provides cant hurt. Just make sure you leave it sitting long enough to dry before using the box.

deathcloud · Post by **deathcloud** » Fri Nov 27, 2009 3:44 pm

Ok thanks man. You guys are giving me confidence.

I will find a good wood glue... Any you do recommend? Just in case when I go to Lowes or something I have an idea of what I should get.

I am excited to get my first box done. And have it properly tuned too! That will be the cool part.

So far from my specs I have it at 28hz but when I put the woofer in I believe that that will bump it up to 29hz via the displacement of .16 cu ft. Hopefully.