Car Audio Advice from the Audio Gurus: Use "Search thread" before posting a new Q!

[navin]

standard fiber hatches are not rigid enough to provide a good foundation for 6x9s. if you are lucky you will get some boom (colouration) if you are not you will get severe rattle.

my last zen (1995) did not have a hatch so please help us out here....where is the recommended instal location for the rear speakers? If it is the rear pod like my Octy or my wife's sail then you can get by with a 4" rear in the pod and a powered sub box/tube for the bass.

[Sam Kapasi]

Originally Posted by Vivekphadnis

I was experimenting with my car CD player and the JBL speakers. The 936s actually sound pretty decent in the box they came in. I am wondering if I could make the same sized boxes with 18mm MDF and use it.

Also, one more thing. Do any of you know if a 9-0-9 5 amp transformer will be enough to run a car stereo off the mains at home. And does the power supply need to be regulated?

I will leave the box question for Navin.

A 9-0-9 will generate about 11.5 volts DC unregulated. This will run most head units yes. I would much rather use a 12-0-12 and regulate it using a simple Zener and NPN metal transistor. Like the 2N3055. Make sure you use atleast a 2200MFD, preferably a 4700 FD filter cap.

[Vivekphadnis]

My head unit manual says it can take upto 14.2V DC. So, will a 12-0-12 transformer not be a little too much. It can be kept at 12V with a zener but you know, just to keep a safe margin. Should a 5A secondary winding be enough?

[Sam Kapasi]

Originally Posted by Vivekphadnis

My head unit manual says it can take upto 14.2V DC. So, will a 12-0-12 transformer not be a little too much. It can be kept at 12V with a zener but you know, just to keep a safe margin. Should a 5A secondary winding be enough?

Even an unregulated 12-0-12 will give out about 14.5V under load, so it's better you use the 12-0-12.

5A is more than enough. Even 3A will do.

[Vivekphadnis]

I am currently using a variable power supply unit. The max current is about 2A. The transformer and LM317T regulator heat up like crazy. I changed the heatsink and put a bigger one. That gets hot too.

[Sam Kapasi]

A lot of people ask me the difference between these 2 enclosures. Just thought i would offer my opinion on this once and for all. I'm not going to go technical at all, just a broad, easy to understand viewpoint on 2 kinds of bass enclosures.
Tubes:
AKA Basstube, Bazooka etc etc
Available in 8 10 and 12 inches (JBL makes only 12, blau makes 8 &10 etc) An extremely popular enclosure. The tube is a very interesting method of box constructions. Most tubes are made with multi layers of paper, thereby creating a sort of strong cardboard. Imagine a tennis ball tube? this ones built like that only much much stronger and thicker.
Due the the way the tube is built, the low frequency extension (read:deep bass) is higher. A lot of people may not like the excess bottom end (read:BOOM). I find that the tube offers heavy low end that travels better through seats and metal. I normally recommend a tube for a 3 box car. Tubes do sound very nice in a hatchback, but often are just too big for a hatch like a Zen. If you listen to pure music, (read: no eminem and PVD) then you will not like the tube too much. But if you like some serious eyeball shaking and like to have fun with bass, then it's a tube.

Boxes:

This is a smaller option, albeit slightly pricier than a tube, if the box is original imported as well. Ofcourse there are many people who will make boxes for your subwoofer, but as Vivek and Navin will tell you, most boxes that are readily available for your woofer are a JOKE.
Readymade boxes are a good option as the boxes have been engineered specifically for the woofer at hand. However the box design is a compromise on space (read: the smaller the better) so you will find most ready boxes to be less boomy. Also these boxes are generally made out of MDF board-wood and have a nice finish too.
If you like your bass tight and hard and dont want to sacrifice too much of your boot space, the box is for you.

Cheers
Sam

[Sam Kapasi]

Originally Posted by Vivekphadnis

I am currently using a variable power supply unit. The max current is about 2A. The transformer and LM317T regulator heat up like crazy. I changed the heatsink and put a bigger one. That gets hot too.

The LM317T current specs arent good enough. Vivek you get some pretty decent car battery eliminators in the electronics market. They arent bad at all for the price. Save yourself some trouble and buy one.

[navin]

Originally Posted by Sam Kapasi

I will leave the box question for Navin.

Vivek has seen my boxes (on diyaudio.com) i think he knows my answers too!

BTW the 936 come in a box?

[Vivekphadnis]

Maybe I should. They would have done the dirty work of sorting out the correct current rating transformer and all that. I can worry about more worthwhile things like boxes for my JBLs.

[Sam Kapasi]

Originally Posted by karthik247

hey SAM,
heard a lota abt ya in t-bhp. i kno this is not the proper way to ask for some help, but i wnted to know abt upgrading my music sys. right now i have a pioneer 944amp, pioneer2000W woofer, pioneer HU, kenwood components. by the way my car is an octy. So what more do u suggest....i can spend another 20k on the upgrades..

Hi Karthik,

Sorry to transfer your question here from PM, but it's easier and other folks can read it too.
The pio 944 is a legendary amplifier and i wouldnt change it at all.
If you would like to spend 20k on upgrades and want to change your sound completely, I say change your HU immediately.
I suggest an alpine head unit, you would be surprised at how the entire sound will change the minute you change that.
If you have the inclination and the money, replace your woofer too.

[Vivekphadnis]

BTW the 936 come in a box?

I meant the cardboard packaging when I bought them.

[navin]

try this instad of the 317. http://www.national.com/pf/LM/LM338.html or if you want to build a discrete PSU u can use this http://www.ee.washington.edu/circuit...its/Supply.GIF

[navin]

those cardboard boxes would be very lossy. are you sure you are only listening to the woofer or also to the box. you can make a quick and dirty box out of MDF or you can do it the old fashioned way (marineply, fiberglass, lead, etc...).

BTW car speakers like lossy boxes since most fo tehm are free air and have T/S parameters to match. So I would consider an aperiodic box for this purpose.

first build a stuff sealed box, then once you got a proper sealed box (i suspect the system Q would be high) then you can add a aperiodic port or 2 to tune the box to you liking.

[Vivekphadnis]

are you sure you are only listening to the woofer or also to the box.

I don't know.

try this instad of the 317. http://www.national.com/pf/LM/LM338.html

I suppose I could just replace the 317 with the 338.

[Sam Kapasi]

Chal Drool photo time.