_S7V7N_'s box

[talnlnky]

so... a few issues, kicker didn't really give much data about the Cvr12... there is a dvc2ohm & dvc4ohm unit... they gave specs, but didn't tell me how they got those specs, I don't know if those are with the coils measured separately, in series, or parallel wired (it makes a difference)... but it doesn't really matter too much anyways because they only gave me about 5 useful specs, and realistically I want more like 8-15. I can have the program calculate some of the others, but I had to guess on the SD (cone area) and so my graphs should be fairly close, but they may be off.

also... you didn't tell me what you wanted... so the default is a street beater setup.

To be honest, looking at the QTS, it's not really designed to be in ported boxes, and if you were to put it in one, it might sound weird. The group delay is weird, normally the group delay will spike, and it'll be this weird looking bell curve type line... this one spikes... then slowly rolls off. Luckily, it doesn't spike too high, so this might sound relatively tight, but there is a 5dB bump in the frequency response around 50hz... which sure won't help with giving you a tight sound... and that is with the box tuned to 33hz, I can only imagine how big that peak would be if you tuned at 40hz like may store bought ported boxes are... but then again, kicker is kind of notorious for having big peaks in the response in the 40-60hz range. It gives the illusion that the sub is a lot louder than it really is.


If you went ported, I'd recommend using dual 4" aeroports (the round ones with flares on both ends), that or about 25sq in of port area.

[talnlnky]

i gotta spend some time with the fiancee, i'll try and design up their box, and compare it with what I have posted above too... that big sealed box is huge, the ported box is a bit small, but that is probably to keep size down & also keep that peak in group delay down too.

it's easy to tweak with a box to get a slightly difference response... with sealed boxes you can't really do much tweaking... but with ported you can.

[_S7V7N_]

http://www.kicker.com/sites/default/...2007CompVR.pdf

That's where i got all the info, i really want to go with slot ports, that's the one on that page, and fire it straight through them 6x9 openings since my seats don't fold down.

[talnlnky]

ok, the pdf said the coils were in series, still doesn't say what the Le, Bl, Sd, mms, or about 10 other specs are. I'll re-run the graphs tonight.

as for slot porting through the 6x9 holes.... you don't want the ports taking up all the room of the 6x9 holes. At box tuning, your port is making half the noise, your sub is making the other half. Above tuning, the sub is making the noise, below tuning your port is making the noise. 95% of what you will hear will be at or above tuning, so you don't want to obstruct the wave that the sub is producing from entering the cabin.

[_S7V7N_]

Looks like they're not good at giving info...Loll deff not an Sq sub, i guess we'll just have to go with noise....I guess what would be the best box for Spl.

[talnlnky]

Originally Posted by _S7V7N_

Looks like they're not good at giving info...Loll deff not an Sq sub, i guess we'll just have to go with noise....I guess what would be the best box for Spl.

spl boxes aren't something you want to have in your car.... trust me, i've done it, and a box that is even remotely designed for SPL is annoying, and dangerous to use for daily driving.

A street better alignment is what you want, which would be tunning in the 35-40hz region + a subsonic filter set just below tuning (say 5hz below).

it'll be loud, muddy, and .... did I say loud?

[_S7V7N_]

Originally Posted by talnlnky

it'll be loud, muddy, and .... did I say loud?

That sounds kind of ...Fun Can that design have them L ports in there? or is it going to be them round ports ? And i seen them recommend polyfill, i've used this in a sealed box, but a ported ?

[talnlnky]

the shape of a port really doesn't matter... what matters is how long the port is & the area of the port. you increase the area, then you increase the length of the port.

the nice round aeroports are very smooth and help keep port noise down, I've only used them once on my own boxes, generally I do slot ports cause they are free, and aeroports cost like $15 a pop... My HT sub I had some issues with the size & length of the port, going with an aeroport helped me out... its kinda like cheating.

If you do a slot port, I recommend taking a 1/2" round over router bit to both ends of your port just to help give it the tiniest bit of flare.

[_S7V7N_]

In your opionion if i started out at about 2 cu ft of airspace per chamber tuned to 35 Hz, would that be a good starting place ?

http://www.kicker.com/sites/default/files/CVR_0.pdf

I think that site had more of the tech stuff, 07CVR124

[talnlnky]

Originally Posted by _S7V7N_

In your opionion if i started out at about 2 cu ft of airspace per chamber tuned to 35 Hz, would that be a good starting place ?

http://www.kicker.com/sites/default/files/CVR_0.pdf

I think that site had more of the tech stuff, 07CVR124

nice, those are the specs I wanted... now... do you have the DVC4ohm or the DVC2ohm sub?

[_S7V7N_]

Dual 4 Ohm

[talnlnky]

k... will try to attend to some new graphs tonight... no promises tho, never know what my evenings are going to be like until I get home. Fiancee in grad school, and preparing for a wedding in 3 months.... there's always something going on it seems, Unless she's at work/school, i don't get on the computer.

[_S7V7N_]

Family first bro, i totally understand, i'm in the same boat, Wed's and Thurs are my days off, And myself and my g/f work diff schedules so our evenings are spent together when i'm off since we don't see each other much the rest of the week. My baby bro is getting married in July so i know how that goes, i have to go get fitted and a million other things, and being his best man i have Loads of crap as well..So no worries bro, I look at it as a favor and you helping out when you can.. Beggars can't be choosers, So i'll take whatever i can get whenever the info comes in. I'm not at the box building stage yet anyways financially..Maybe ina few weeks i'll be ready to go forward on that.

[talnlnky]

Originally Posted by _S7V7N_

Family first bro, i totally understand, i'm in the same boat, Wed's and Thurs are my days off, And myself and my g/f work diff schedules so our evenings are spent together when i'm off since we don't see each other much the rest of the week. My baby bro is getting married in July so i know how that goes, i have to go get fitted and a million other things, and being his best man i have Loads of crap as well..So no worries bro, I look at it as a favor and you helping out when you can.. Beggars can't be choosers, So i'll take whatever i can get whenever the info comes in. I'm not at the box building stage yet anyways financially..Maybe ina few weeks i'll be ready to go forward on that.

have you ever made speaker boxes before? .... or done much wood working before?

3/4" MDF is generally the wood of choice for boxes, partical board is just too porous & doesn't hold up as well. If you can source it, and afford it, Baltic Birch or some other Marine Grade Plywood is optimal (low weight, extremely rigid) cost is usually 2-3 times that of MDF tho.

A router with a circle jig is a nice tool to have for cutting sub wholes (or port holes), but a jigsaw can do the job as well, just not as perfectly.

Box building can get spendy quick, the costs in paint or carpet can add up, and the box material you choose can be spendy too (MDF/BB/Fiberglass).

ok, time to go home and run a mile with the dog.

[_S7V7N_]

Yeah i live in some apts so i don't have anywhere to work on the box, but i do however have somebody who told me to just buy the wood and labor would be about 25 bucks, so i'm guessing around 75 bucks total, 100 is the limit.

[talnlnky]

ok... my slow self finally got around to putting in the new specs, and making a new graph. as you can see, there is a 2cuft @35hz a 3cuft @ 30hz, and a a 1.2cuft sealed box. There is a HUGE peak for both the ported boxes, and they also have a weird double peak in the group delay, the group delay could be worse (at 50hz it is pretty high though).

Honestly, i'd go with a sealed box... and if you decide its not enough, then build a ported box with a nasty peak in response. The sealed should sound a lot better, and be smaller to boot.

[_S7V7N_]

The sealed box i have now is 30" width 14 Height and 14 Diameter, made out of 1/2 Inch Mdf with the divider in the middle...so i'd maybe 1.0 per chamber, don't get me wrong its like i have two silver back gorillas wrestling around back there, and i believe the Small amp i have on it is not giving it quite the juice i'm looking for. I'll try to video the flex on my trunk, it's pretty awsome.

Any idea what size that Ported box would be as far as L W H . And 2 cu ft per chamber right ? I want to stay @ 35 Hz.

[_S7V7N_]

By the way thanks alot man for taking time and running these specs for me, i sure do appreciate all the help.