How to get more db with 1 12"... tricks and tips

[Васил Игнатов]

So any sub can work in any type of box if it si calculated and made good?

[getlocivic]

yea i seen low 11v you NEED more electrical before sometihng dies stuffs designed to run on 12v for a reason

[getlocivic]

and that sub is already reaching its max excursion limit

anybody else see the "ring around the collar"

[Quiet]

So any sub can work in any type of box if it si calculated and made good?

Yes and no. I wish it were that simple.

Depending on the T/S params, some subs are better suited for ported/4th order and some are better suited for ported 6th order. The (oversimplified) equasion is called EBP, Efficiency Bandwidth Product. I'll post a calculator for it in a minute.

A sub will actually produce sound in any enclosure. Whether or not it sounds good to you is up to you.

EDIT: Random EBP calculator http://www.calculatoredge.com/new/bandwidth.htm

[transeunte]

The real secret of a high SPL is to take into account the resonant frequency of your car, usually somewhere around 50-60 Hz and build a box that peaks at this same frequency (you will need the Thiele-Small parameters of your sub, though).

Problem is, to figure out the resonant frequency you will need a reference/sealed box, and a decent mic and software analyzer. Otherwise you can just play those Bass Mechanic CD's that have pure sine waves on them and, by ear, figure out on which tracks your car resonates (vibrates) more.

But first you need some sound deadening (or at least some added mass) to your trunk: when it rattles, it absorbs the sound waves, instead of reflecting it - that surely steals some precious DB's. Note that any sound deadening should be done BEFORE figuring out the resonant frequency of your vehicle (it should be higher afterwards).

Also remove (or take out sight) any baffling material from the interior: remove the rear decklid, fold rear seats and recline passenger seat. Remove all seats if rules allow you to, even carpeting. Reflected sound waves are your friends here.

Regarding the box itself, check where the microphone will be, and measure your target burping frequency: figure out the sound wave size, and position the subwoofer on a place where the sound wave hits the mic at its crest. As you might have noted already, the highest SPL doesn't occur exactly on the face of the subwoofer, but some meters afar. Since the Renault 19 is a small hatchback, you will probably have to leave the subwoofer facing the rear, and account for the sound wave reflection on the rear hatch - that's why making it stiff is so important.

Oh, and please set your gains properly, and DON'T turn your amp until you burp. Electronic devices loose performance when run hot.

Hope that helps, it's helped me get 134.8dB on a 240W sub - and I hadn't deadened or stripped the interior yet.

[andrew018018]

So which is better ? My type of box with this kind of port or 6th or 4th order bandpass? Well i know that every car is different but even the bass boost (from headd unit) is not 100% sureness that will improve my result?

The 6th and 4th orders can achieve higher spl but they are much harder to get right

[Quiet]

Yes they can. They make more efficient use of the back-wave. Unless you build it spot-on, though, you will most likely trade sound quality for SPL. You have more room for error on a 4th order than a 6th order, but have higher gain potential on a 6th order.

Generally speaking, the higher in "order" you go, the more precise the box needs to be.

All this being said, i've seen tons of 4th orders and 6th order boxes sound like complete ass.

[Васил Игнатов]

Thank you very much guys! Well the mic will be placed infront of the car maybe near the front window. There are no restriction about the seats or moving things in the car. Yesterday i've played with audacity and made some "tones" from 30hz to 70hz (30,31,32,33......70hz) I'm thinking about putting the sub in sealed case and giving him some freq and the mic will say what is the resonant freq of my car. There is no time for deading my car, and it will cost me a lot of money. I'm thinking about but it will cost me much and now i dont have enough money. Here are my subwoofer specs : http://www.gz-usa.com/subwoofers/110/uranium-gzuw-12xii/1283797117.pdf (i'm with the 12"). I'm thinking to remove the rear cortex (for the rear speakers) and giving my new box space. I was thinking to make it so big that the subwoofer will be beyond back seats heads. If i give you some specs for example how much place there is in the trunk can you make some example box......

[alaskanzx5]

depending on wich way the box/sub is facing makes a difference to. a good idea is to get the car metered with the box facing several directions. once you fine which direction is best moving the box foward back wards and side to side is the next step in finding the best postion for the enclosure. then you can also try having the port on the driverside and then the passenger side.

wityh my last setup just mocing the box around a little i gain about .5db placement is a fairly big factor in spl. not every setup/enclosure/sub will be best in the same placement as the one before.

[Васил Игнатов]

A friend of mine said that the greatest box for this car and subwoofer (this is his job) is a ported box with about 40hz tune and about 120liters and subwoofer facing up..... he said that he is hoping to reach 144db. This is this subwoofer limits. What do you think about?