Need Help Adding Tweeters to Speakers

[Wikerman]

Hi Guys, Audio noob here but pretty good with a soldering iron..

I am actually trying to add a set of tweeters to my car, you see I own a bmw e36 318is which came with speakers on the door cards, I recently replaced the door cards because of sagging door inserts (a common issue with these cars) and the new door cards have tweeters installed with speakers.

Anyway there aren't any connectors on my car to connect these tweeters so long story short I need some help connecting them if possible.

Both the speaker and tweeter seem to be 8 ohms, so I was told to add a capacitor and a 4ohms resistor to the tweeters..I was also told this may not be safe for my cd player? I got a decent sony cd player.

I dont know, I do have some caps at home so if you could tell me how to make it work I could give it a go...

Here are some pics,






the speaker





and the tweeter

[sdclc126]

Are you replacing the existing tweeters? If so, what with? Also you might try the car audio forum.

[tinitus]

moved to Car Audio


moderation

[Wikerman]

No, I am actually trying to add tweeters, my car came with door speakers but not tweeters, just need help wiring them, properly, have more details in the topic. please have a look. would appreciate the help.

[Perry Babin]

You can connect them to the wires that are feeding the midrange speaker but you'll have to insert a crossover between the wiring and the tweeter (in either the positive or the negative wire). A 4.7uF non-polarized capacitor should be OK.

[Wikerman]

Okay So I solder 1x 4.7uF capacitor to the negitive and positive terminal of the tweeter. then I can connect them to the wire feeding the midrange speaker, I was also told to install a 4ohms resistor on the positive wire in order to correct the impedance an bring it all back to 8ohms? is that correct? Also Do I need a non polarized cap? how do I tell if my cap is polarized or non polarized ?

So thats all I need to do? nothing to worry about it causing any damage or something to my cd player?

I was given this instructions by someone, please have a look..

Wire the capacitor across the positive and negative terminals on the tweet

Cut the wires that go to the original speaker, strip back
So now you have a wire that goes to the car, one to the original speaker and one to the tweet and obviously the same for the negative

solder the resistor to the positive wire from the car then solder the positive tweet wire and speaker wire to the other side of the resistor

Solder the negative tweet wire and original speaker wire to the negative wire

Heat shrink over them all job done

Thank you for your time and help.

[Perry Babin]

Negative OR positive, not both. If you solder it across the positive and negative terminals, it will shunt all of the high frequencies away from the tweeter.

I don't think you need the resistor. Adding it will increase the impedance slightly but with a 4.7uF capacitor, the tweeter will only load the amp significantly above 5000Hz. It's not likely to be a problem unless the amplifier driving it is very fragile.

You need a non-polarized capacitor.

There are no guarantees that modifying the system won't cause any damage to the CD player. There are always risks involved and something as simple as letting a wire touch to ground for a fraction of a second could be enough to cause extensive damage.

[Wikerman]

Okay Thanks, So to speak, Whats the difference between a regular capacitor and a non polarized capacitor? How do I know if its the non polarized capacitor? I mean distinguish the difference? is there any electronics I might be able to salvage some from or I get them from the store.

I made this diagram for wiring tweeters to the e36 bmw speakers...is that about right for the crossover? I am using a 3.9omh resistor on each door along a 4.7uF non polarized capacitor.so overall I am thinking I should be safe with this, I mean I am good with the iron and heatshrink cables and everything..let me know what you think..

[Mooly]

Non polarised means it can tolerate DC voltage of either polarity across it up to its rated voltage. Normal electrolytic caps are polarised and and must be fitted the correct way around if any DC is present.

You can make a non or bi-polar cap by connecting two electros in series. For 4.7uf you would use two 10uf caps to give a total of 5uf for the series cap. Connect either plus to plus or minus to minus for the series connection. It doesn't matter which.

Edit... the resistor for the tweeter would go in series with just the tweeter, not the main speaker as well.

[Perry Babin]

Normal (polarized) capacitors are designed to work with DC only. Audio is AC so you need to use non-polarized capacitors.

The diagram is correct. You should know that this will slightly decrease the output of the midrange speaker. The resistor may also dissipate a great deal of heat (depending on how loud you play the system). It could get hot enough to melt plastic. I'd recommend a 5 watt resistor as a minimum.