custom sub boxes for 3 subs ( kicker comp ) Help with dimensions etc

[DmanVT]

hi all, i started off with a single kicker 12" comp sub, ( come in a bundle with kicker gear ) running off a zx350.4 amp ( 150w x 2)



I recently felt the need for more bass, so i upgraded the kicker to a 12" alpine ( 300w) and bridged the kicker amp.

I made a custom face over the front and added a couple of sixes.



Now i have 1 kicker comp sitting on my bench.

That leads me to my new plans.

I want to have the alpine in the fabricated 12" box in the center and then build two custom boxes either side of the alpine box on angles to house the two kicker comps ( i will purchase another if this is possible )

Design:



These are the specs of the Subs that i am putting in.



I was going to make the box around

500-600mm deep x 500-600mm wide x 800mm ( on angled face where sub goes) x 400-500mm high

The internal dimensions come to around 1.9 - 2.2 cubic feet

Can anyone tell me if this would be good enough for what i'm wanting to do?

And also i was wanting to mount the subs backwards on the sides and flat on the front.


If anything is badly wrong can you please help me and if you have any feedback or suggestions i would be extremely interested to hear what you have to say, This is my first box and i don't want to screw it up badly!

Thank you heaps,
Darcy

[AmmoJammo]

I want to have the alpine in the fabricated 12" box in the center and then build two custom boxes either side of the alpine box on angles to house the two kicker comps ( i will purchase another if this is possible )

Darcy

please don't mix subs, and enclosure volumes.

[HCVP]

IMO mixing subs in an application like this is fine. All he's after is bass, and i expect the more he can rattle, the happier he will be.

No i wouldn't do it in my own vehicle, but then again i wouldn't have 3 subs. I won't try and explain why more subs and extra surface area doesn't mean it's going to sound better.

[DmanVT]

I have changed my mind I want to make the two customtriangle boxes and just run with the 2 alpine subs. How much bass or loudness would I lose if I make sealed instead of sorted boxes?

[Nic92]

oh yeah sorted boxes LoL.

[DmanVT]

haha oops, ported haha i was on my phone :S haha so yer how much of a difference would it be between a sealed and vented box?

[Nic92]

imo ported sound alot better and not as easy to build/design as the sealed, also depends what type of music you lisen to, you get sht all lows out of a sealed box mainly for high frequency bass and ported if you tune it right you could have really low lows and/or really high highs, someone else will probs give you a better explanation lol

also in size difference ported take up much more room of boot space, so if you are limited with space then sealed will be a better option

[kcpwns]

Probs best to do a search on ported and sealed I think it may have been covered. But I prefer ported.

[DmanVT]

i want to make it ported but i've heard that if you get the port specs wrong, you can kill your sub. :S

I want to build the triangle boxes with 2 port holes going up through the parcel shelf grills.

would this website be ok to use for the port calculations?
Port Length Calculator

i want it to be tuned around 50hz

( i've been told thats a fairly good frequency to tune at ) But i have no idea on how port tuning works etc.

[HCVP]

50hz is too high. I wouldn't tune much above 35hz unless it's for SPL duties and you know the peak fq of the car.

If you can't decide between ported and sealed and don't know anything about either, just use a sealed enclosure. But honestly a couple of 300w subs in a car the size of a Commodore it's hardly going to make a difference either way.

Unless you make up your mind about exactly what you want to do then we can't help you any further.

[DmanVT]

so are you saying sealed will be basically the same as ported in my car? or are you saying 2 subs will be no different to one? haha and yes i agree with the frequency i was going to have it around 23-30hz and i went to a guy today and he said thats way to low and the lowest i should go is 50hz and i was like.... umm..... so i had no idea then haha

[Nic92]

Lol. 30-32hz sounds really nice and low or even 35hz you will get some good highs , a ported box did make a huge difference in my commodore because i was running 2 jl w1s 150rms each in a sealed then i changed to ported 35z and they sounded really nice, even vibrated my steering wheel

if you go ported make sure the port and box size is right

[HCVP]

so are you saying sealed will be basically the same as ported in my car? or are you saying 2 subs will be no different to one? haha and yes i agree with the frequency i was going to have it around 23-30hz and i went to a guy today and he said thats way to low and the lowest i should go is 50hz and i was like.... umm..... so i had no idea then haha

I'd aim for about mid 30's. I meant that unless you know a lot about tuning enclosures, then i presonally wouldn't bother. A sealed enclosure on the larger side will compensate somewhat for low fq and output. If your thinking you want a ported enclosure because it's not loud enough, then your going about it the wrong way.

What i mean about the 2 subs is that they are only cheap entry level subs, and you might be expecting too much from them. I would just be running them in some well built sealed enclosures. Even some pre-fabs if you can find some larger ones, and add a little internal bracing and a few coats of resin.

[WHYtheFACE]

What i mean about the 2 subs is that they are only cheap entry level subs, and you might be expecting too much from them.

This is a good point, they are only cheap subs, and you are only running your current sub at 175w :P

[Nic92]

how loud are you expecting them to be? it is a big car..

[DmanVT]

well i have one at the moment and its fairly pumping i just want it the same but dnt want to have to be running them as hard to achieve that

[DmanVT]

I just finished making up the temp[late out of cardboard to see rough dimensions.

Does this look like an alright box for a sealed box?

[HCVP]

Not point in just showing us some pictures. You need to calculate the internal volume, and take into consideration the volume taken up by the driver.

You need to design the enclosure specifically for the sub. If you after something neat and tidy i suggest just getting a pair of the pre-fab jobs designed to go in the corners near the tail lights, and just improve on them.

I'm confused about what amplifier/s you are using to drive the subs, can you clarify please? If i read it right you are using a 4 ch amplifier for the intended purpose of driving 2 subwoofers. This is an amplifier best suited to driving-

4 full range speakers,
2 full range speakers and a low powered subwoofer,
2 full range speakers when bridged to 2 channels,

It is / was not ever intended for running 2 subwoofers, especially one's with a power handling of twice the amps continous output. Your subs are well under driven and if your not careful your likely to overdrive the amp resulting in clipped signals.

TBH i would forgot about fancy designs and layouts and multiple subwoofers and so forth. Use the Alpines you have, and buy an amplifier that's appropriate for the job. Grab some cheap pre-fabs and improve them like i said with some internal bracing and some coats of resin. Run a subsonic filter if you would like to run the subs a little harder without bottoming them out.

[DmanVT]

at the start i had 1 kicker comp 150w rms, i upgraded to the alpine 300w, at the moment im using the kicker amp to run it ( bridged ) as the amp is SAMS compatible.

Soon ( after i get advice on this box and make it ) i will add another sub and will get either a 300w mono block at 2ohms ( put the subs in parallel @ 300w rms each and 4 ohms) or get two 300w 4ohm mono blocks to run them. Unless i get another opinion, But for now im just not pushing them.

The internal volume works out a little under 1.91 cubic feet I (without bracing)

Alpine suggests a box between .85 to 1.5 cubic feet for an optimum sealed box it is 1.20

what happens if you run a larger box? ( i'm sorry i dnt know alot about box's in terms of what happens when you go larger or smaller )

[HCVP]

Your post doesn't make any sense mate. What do you mean by the Kicker amp bridged? It's a 4 channel, so your only options are -

4 x 60 @ 4ohm
175 x 2 @ 4 ohm

I'm also confused about why you would run one sub from the 4 ch amp and run another from a mono block. Or why you would buy 2 mono blocks.

The idea it to drop the impedance level lower, not keep them at 4 ohm each. You'd also like a bit of head room too above the rated input power. What are the voice coil configurations of the subs?

If you use a larger enclosure, you gain some efficiency, more output, and the ability to play lower fq's. But remember we are talking small differences, it's not night and day. The down side is the bass is not at tight or controlled due to the extra air behind the driver. If it wasn't such a big car and the subs had more impact, you could start off with a larger enclosure, and experiment by adding blocks to the enclosure and find out what size works the best. But two Type S subs in a Commodore is never going to make your eye's pop out.

Ported will also gain some efficiency, and the port is there to unload the sub as the desired fq. So the sub is it's loudest at the port tuning, at which point all the sound is coming from the port, not the subwoofer, you won't actually see the sub move when this is happening. Ultimately a ported enclosure if built correctly will be louder than a sealed enclosure, but the response curve will have peaks where the sealed enclosure will have a more flatter response.

It comes down to personal taste really. A lot of people will give their opinion on which is better but with little idea as to how each work.

[DmanVT]

Sorry, i'll try and clarify, The kicker zx350.4 is capable of having one section bridged and one section not bridged ( SAMS) stereo and mono simultaneously.

I can run 2x 90w @ 4ohms and 1x 175w @ 4ohms

At the moment im just running the alpine at 175w and not pushing it so that way i dnt send square signals/distortion to my sub. Follow me so far?


Now due to having bass, i want more so i will invest in another alpine sub the same as the one i have now.

I will get an amp that is capable of running the two subs together and then use the zx350.4 to run other speakers.

So thats the reason for getting a new amp. With me?

Sorry if i'm not making any sense, i will try and describe it better if you don't understand me :/ sorry

[DmanVT]

What are the voice coil configurations of the subs?

The subs are dual 2Ohm :/ so i can make them either

vc's in series making each sub 4ohm, connecting subs in parallel with 300w min mono block @ 2ohms
vc's in parallel making each sub 1ohm, connecting subs in series with a 600w min mono block @ 2ohms

I think they are my options or 2x 300w monoblocks @ 2ohms and each sub @ 2ohms

[HCVP]

That 90rms x 2 rating is at 2 ohm your speakers are likely to be 4 ohm. The amps 4 ohm rating is 60 rms.

Anyways i've sorted forgotten what the point of the thread was.

Decide on your enclosure type.

If you want sealed, i'd aim for around 1.5 cu ft before driver displacement. Ignore Alpine's suggestions. I have personally built enclosure's for their subwoofers and they do perform better in a larger than reccomended enclosure.

If you want ported i'd go somewhere around 1.5 - 1.8 cu ft, again before displacement. I'd aim for a tuning fq of around 35hz. I'd also buy an amp that is equipped with a sub sonic filter regardless of sealed or ported. The lowest of fq's will always limit a speakers ability.

Or (my favourite) sell both the different subs you have. With that money, and the money you would use to buy another S Type, just buy one "good" subwoofer. Then repeat the process as above.

[HCVP]

The subs are dual 2Ohm :/ so i can make them either

vc's in series making each sub 4ohm, connecting subs in parallel with 300w min mono block @ 2ohms
vc's in parallel making each sub 1ohm, connecting subs in series with a 600w min mono block @ 2ohms

I think they are my options or 2x 300w monoblocks @ 2ohms and each sub @ 2ohms

Wiring in series is never a good idea IMO. Run them together at 0.5 ohm. Some amps can get a little smokey below 1 ohm but with the light load they would present ant decent amp would be allright.

[DmanVT]

i have 4 speakers running off the 90x2 each 4ohm in parallel ( 2ohm load)

anyway, i think for now i will go with a sealed box, it seems easier to build and in terms of vent iv heard that you can destroy your sub with the wrong sized vent, so for now i will go with a sealed box at around 1.5

If i have sub reversed ( magnet out) do i need to make the box smaller?