VW T4 Forum - VW T5 Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
35 Posts
Discussion Starter · #1 ·
Hello

I'm being thick - but I've got some 4" JBL speakers for the front of my Velle and want to control the amount of bass (limit it) that's going to them.

I've read this:

http://www.matey-matey.com/capacitor_crossovers.shtml

.... but still not sure what capacitor to use.

The speakers are rated:

# Peak power: 100 W
# RMS power: 35W
# Sensitivity: 90 dB
# Frequency response: 90 ~ 20 kHz

Can anyone tell me capacitor crossover I need to use?

Thanks in advance

therealgiblet
 

·
Registered
Joined
·
92 Posts
Looking at the article it doesn't seem too critical.

I'd suggest you try 220 uF (microfarad) to start with. As he suggests, if you want them to behave more like tweeters (your mid range and bass comes from other speakers) then 100 uF would be a good value.
I've not tried this myself as my power level is low enough not to need it, but principle is good.
 

·
Registered
Joined
·
78 Posts
After a lot of searching and head scratching I still am not quite there! Can somebody please help? Or_Gazm?

On recommendations elsewhere I have a pair of 10cm Pioneer speakers (TS-G1011I) to do a straight swap for the OEM ones in my T4's dash.
These will be the only speakers I have for a little while. I hope to add a pair of slightly larger round speakers into the camper conversion later this year. I have no plans for Amps or Subs as I should be happy enough without I reckon.
I will buy some new speaker cable (2.5 or 4 mm, flexible, nothing special) having done some research. (Speakers came with 2x 30cm cables which look pointless to me length-wise?!)

Questions:
A: Is it worth me putting a capacitor in with the dash 10cms, or not?

B: If so, what is the suggested appropriate value? 220 micro farad?


Maplins do Audio-grade capacitors (I'm assuming they're better than standard components?), but not at 220 micro. My electronics knowledge is rusty. http://www.maplin.co.uk/audio-grade-polypropyleneaxial-capacitors-393

Speaker specs from the box:
110W max power
20W nominal power
4 ohm impedance
 

·
Registered
Joined
·
1,979 Posts
Looking at the small reference table at the bottom, the assumption here is that the speaker impedance is 4 ohms; (it usually is for the fronts, but I have on occasions seen 8 ohm speakers here).

Assuming that you do have 4 ohm speakers, what do you want the cut-off frequency to be. If you're using 220uF as in the example your exact cut-off frequency will actually be (assuming my maths is correct; see HPF equn.: 1/(2 x pi x R C), where C if the capacitor value and R is the impedance of the speaker in this case) a little over 180Hz. Your choice basically depends on the value you want and in turn finding the closest value to the exact calculated capacitance.

As for whether it's worth it, I reckon it's a preference thing really. Do you have any other speakers capable of handling the lower end (sub, mid ranges...etc)? If so, I'd say yes. That being said, even though you are removing the low end from the speakers, you could save them if the volume is accidentally cranked past the point of no return for said speakers.

I hope that made sense, I definitely started to ramble after a while...
 

·
Registered
Joined
·
1,458 Posts
wow, that site takes me back! feature on my mk2 VR6 on there from YEARS ago
 
1 - 8 of 8 Posts
Top