Crossovers!

[Elektix]

Evening all,

I seem to be having a nightmare getting a straight answer on this question. Hopefully you knowledgeable people will be able to help //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

I have currently, a set of Focal components 6.5"/ 4" and tweeter. They come with there own crossover.

I also have another set of Focal components. 8" with tweeter. This does not have a separate cross over.

I am looking to install tweeter, 4" and 8" in the front. Now can I confirm, can I simply swap the 8" with the 6.5" on the crossover?

Assuming you confirm I can.

I will then be looking at putting the 6.5" and tweeter in the back. What sort of crossover will I need for this? A 2 way? A 3 way? Any particular frequencies, brands etc?

I really don't want to damage my new investment straight away, so need to source crossovers fast. And confirm everything I have said is ok?

Here are data sheets for the speakers if it helps at all:

Focal IS200 - 8" and tweeter.

Focal 165a3

Please anyone can you help me? And preferable point me towards some good crossovers!

Many thanks in advance

Nick

Click to read more...

 

[Elektix]

Sorry I can't upload datasheets due to forum rules, but they are easily found on Focals website.

Many thanks

Nick

 

[bubbagumper6 5,000+ posts]

The IS200 components (8" and tweeter) have the crossover built into each speaker, therefor they can be ran directly from your HU or amplifier. It would be fine to swap the 8" in for that 6" and still use the included 3-way crossover but if you want to run all the speakers you have you should run the 165a3 set with it's crossover and the IS200 directly from your amp (or HU). Just remember that running both sets in parallel would present a 2 ohm load to your amplifier.

 

[Elektix]

That sounds reasonable. The only reason I want to swap is because the front doors have the corresponding space for 8", 4" and tweeter. Whilst the rear has space for a 6.5".

So without extending the crossovers or making it difficult, I wanted to swap them round.

How can I go about running the 6.5 and tweeter in the rear? Buy another crossover? If so any advice/ recommendations on what I need/ should buy?

Many thanks once again for your help.

Nick

 

[bubbagumper6 5,000+ posts]

Well if you use the tweeter from IS200 set it won't need a crossover because it's built in, but the 6.5 would need a low pass filter. This can be accomplished with a simple capacitor soldered to the input terminals (this is what you're 8" woofer has).

Notice the cap soldered to the terminals.

As far as a value that's kind of up to you. The original crossover crosses that 6" at 300Hz but if you want to use just that 6" and a the IS200 tweeter in the rear you would have a huge gap between the two. I would suggest going up a bit on the crossover value.

Here's a link to where you can buy those caps (any cap will not work, they have to be non-polarized) 100V Non-Polarized Crossover Capacitors at Parts Express

And here's a link to a chart for determining what size cap to buy for the crossover point you want Car Audio - Speaker Crossover Chart and Capacitance vs. Frequency Calculator(High-pass)

You want to look at the 4 ohm column, and remember you'll be soldering the cap in parallel with the speaker (even though that diagram shows the cap in series).

 

[Elektix]

As an idea, would these crossovers do the job? I.e. Would I be able to use the focal crossover in the front to control the 8", 4" and tweeter.

And these in the rear for the 6.5" and tweeter?

Phonocar 2-Way Passive Crossover

Many thanks

Nick

 

[bubbagumper6 5,000+ posts]

The 6.5's original crossover crosses it at 300hz, that crossover you posted would cross it at 3800hz...that may be a problem

 

[keep_hope_alive Premium Member]

CORRECTION -

you need an INDUCTOR to create a low pass filter (when in series). in the pic above - that is an inductor, not a capacitor.

use the chart to choose the correct inductor.

 

[bubbagumper6 5,000+ posts]

CORRECTION -
you need an INDUCTOR to create a low pass filter (when in series). in the pic above - that is an inductor, not a capacitor.

use the chart to choose the correct inductor.

Or a capacitor in parallel...

 

[keep_hope_alive Premium Member]

Or a capacitor in parallel...

that would create a short circuit above the crossover point. remember that the impedance of a capacitor is near 0 ohms at high frequencies and very high at low frequencies. you only add a crossover in parallel (to increase crossover slope) AFTER an inductor in series - and the inductor needs to be coordinated with the capacitor to prevent the amp from seeing a short circuit.