Creative Thinking (ICE for Leon)

[dj_hektik]

OK OK,

My Leon. Nice car, fast-ish but doesn't sound very good. I want to change that, but my problem is money. I'll need a bit of help to get a good system on a tight budget.

I want SQ, but I can't spend so much money, about 600 pounds to start with.

I already have the following:

- Loads of Stinger cable left over from previous installs - power distributors, 1.2f cap, fuses etc.

- Alpine 9855R
- JBL BTX-250 (100 RMS active bass reflex with passive radiator)
- JBL 250 RMS in ported box
- Magnat Tweeters and Crossovers (i forget the model number, they're rated at 160 RMS)

and that's it really. I have some other stuff but borrowed/lost/missing a part etc. so i dont want to factor them in.

so ... im looking now for an amp to power the JBL 250 and some nice front speakers (can be good 2-way speakers as with the crossover they will function as midbass drivers)

Suggestions?

also any tips on witing in the leon? I will run the wire through the grommet next to the brake cylinder, but at the back of the car I usually get a bit messy under the rear seat. any tips?

Also, what are the colours for the speaker cable coming through the door? and where is the crossover? i want to eliminate the factory crossover and connect the amp to behind the HU. Easier that way and I won't be using expensive speakers anyway.

Here in Saudi Arabia I can easily get the following:

Japanese brands (sony/pioneer/alpine)
Magnat, MacAudio, Rainbow, Kicker, Dragster

that's it really.

Thanks in advance

 

[Icecavern]

Few areas of interest here...

http://www.icecavern.com/forum/index.php?showforum=45

http://www.icecavern.com/forum/index.php?showtopic=1822

If you're after SQ I'd buy a good set of front components ( around £200-£300 ) rainbow would get my vote out of the brands you mention. Forget the Magnat tweeters and crossovers as they will come with the components.

If you're happy with the sub you have then just buy a good 2 channel amp for the fronts. If not get a 4 channel amp and run a small 10" sub off two channels bridged and the fronts off the other two.

Pete

 

[dj_hektik]

the sub i have ATM (the jbl 100rms) is ridiculous. its better than nothing for the time being though.

Also I remembered I have 2 mac Audio Premium 12" subs. They would take up a fair bit of space, though.

Also been on the phone while writing this, sorted a Dragster 2160 Amp for 50 quids (2x160 4ohm, 300 2ohm). Only need fronts and power for the fronts now.

Any tips on the best kind of box for 2 12"s that won't use much space? I was thinking a sealed enclosure with subs facing each other? a bit like this:

=====
|------/ | \
|-----[] | []
|------\ | /
=====

if you can see what I mean ...

Also how can I calculate the volume I need for the sub? the specs are:

DIN diameter: 300 mm
lower cut-off: 20 Hz
upper cut-off: 500 Hz
Nominal Power : 200 Watt
Max. Power: 400 Watt
Impedance: 4 Ohm
SPL: 91 dB
Fs: 33 Hz
Vas: 56 l
Qts: 0.,34
Qes: 0.,35
Qms: 10.,95
Xmax: 9 mm

an isobaric box will need 1/2 the volume, right? also what does nominal and max power mean? does it mean 200rms 400max? or that the sub can take 400 rms?

 

[Icecavern]

Yeah if you face the subs together like that and run one out of phase with the other you'll half the volume needed by the subs, but you won't get any more bass that running one sub.

The sub is a 200wrms sub by the sound of it, but I wouldn't worry about the rating too much. You'll need some box designing software to work out the volume for them I've used blaubox for years and you should be able to find it on the net somewhere.

Pete

 

[dj_hektik]

alright cheers ...

i don't think i will do that isobaric thing after all, i'll make a regular sealed box with the subs beside each other. [OO]

one think I was thinking about though, if both subs are in phase, do I need a divider to separate the box into two "chambers"? i want the box to be as small as possible...

 

[Icecavern]

you don't need to have a divider no, as long as they're the same subs they'll work fine in a single enclosure.

 

[Empi5]

Jeus, and i thought Car modifying was hard.

 

[dj_hektik]

WinISD recommends 33.7 litres for one sealed box with two drivers. does that sound about right? seems a bit small to me.

Also, would dividing the box change the volume requirements? if both are in phase, which would sound better, usually?

this is the result:

Driver : Mac Audio Premium 300
Project by : haitham.ali
--
Number of drivers : 2
Box type : Closed
Box size : 33.7 l


Relative
Freq Gain SPL
[Hz] [dB] [dB]
20.00 -21.47 72.54
25.00 -17.64 76.37
30.00 -14.55 79.46
35.00 -12.00 82.01
40.00 -9.87 84.14
45.00 -8.08 85.93
50.00 -6.59 87.42
55.00 -5.35 88.66
60.00 -4.34 89.67
65.00 -3.51 90.50
70.00 -2.84 91.17
75.00 -2.31 91.70
80.00 -1.88 92.13
85.00 -1.53 92.48
90.00 -1.26 92.75
95.00 -1.04 92.97
100.00 -0.87 93.15

 

[dj_hektik]

OK i have some choices now.

There's only one shop in all of Riyadh that sells decent car audio stuff so I can't look anywhere else, and my only choices are what they have.

They have discontinued Rainbow products, so I asked to have a look in the warehouse, and found a lot of Profi-line speakers - kick-bass, 2-way components etc. I asked for the prices. Slight box damage so I may get a good discount.

Also I was very interested in the Kicker KX700.5 amp. 2200 riyals (300 pounds):

4x 85 RMS + 1x 440 RMS Class D. Ratings are at 2 ohm though, so I dont know what 4-ohm speakers will get - im guessing about 65?

Anyway the salesman didn't know how much discount he could give for the speakers, so i'm going back on saturday. Until then, i'll have the power and speaker cables installed, and take the spare tyre cover to the carpenter as a template to make the false floor.

I still need to know how big to make the box. the WinISD volume seems small? Also is a 10-20% difference in volume OK? or do I have to be accurate?

 

[Icecavern]

With a sealed box you can get away with a bit of leway on the size, but that volume looks wrong for 2 12" subs.

Normally a 12" sub will need between 1 to 1.25cu ft each sub, 33.7l is only about 1.2cuft which sounds very small. If you're going for a sealed box I'd aim for about 2 cuft.

 

[dj_hektik]

alright sorted out a pair of Rainbow Profi Vanadium Kick Bass drivers, will go nicely with the Magnat crossover and tweeters I already have ... Starting work on the wood today