[Guest (MBNZ)]

I have the 10 speaker sound system in my '88 560sel. Are the speakers 4 ohm or 2 ohm? I got a Nak CD45Z for Xmas. Any suggestions about how to set it up?

 

[560sec_vroom]

I am trying to find out the same info, any luck on your part yet?

 

[jbleaux]

I don't know the radio. However, one can take two, 4 ohm speakers and hook them in parallel to make a total of 2 ohms.

Take two 2 ohm speakers and hook them in series for a total of 4 ohms.

There are other derivations, too. Must have the phasing correct or you will lose lots of bass.

joe

Guest (MBNZ) - 1/4/2002 5:14 PM

I have the 10 speaker sound system in my '88 560sel. Are the speakers 4 ohm or 2 ohm? I got a Nak CD45Z for Xmas. Any suggestions about how to set it up?

 

[560sec_vroom]

I have pretty much confirmed the stock system uses 2ohm speakers and the series wiring method wont work unless you add 2 more speakers and sperate into 2 speakers for front group and 2 speakers for rear group. Also the 10 speaker designation is a little missleading they are calling each or the rear deck speakers as seperates 3 each side giving 6 rear 2 door 2 dash. But rears have one signal suppy and uses resitors or crossovers to sepearte signal to the 3. So you can cosider it more accuratly a 3 way speaker.
Doug

PS I am still trying to find out if there is a sipmple cheap way to increase resistance.

 

[jbleaux]

Doug,

First, there is no cheap way to increase resistance.
You can't simply use Ohm's law to figure out the resistor and power rating of that resistor and plug it in the circuit. You would have a lumped impedance bump and it wouldn't sound good.

Resistors used in a crossover network are part of the tuned circuit in combination with a coil and serve no other purpose other than tuning.

What would be the problem with adding the needed speakers to get the impedance that you need? Could you add them and hide them somewhere?

One more thing, in this case, impedance matching is for maximum transfer of power. If you have power to spare, being off a tad won't make any difference.
Where you could get into trouble is seriously mismatching the speakers to the amplifier on the low side and presenting an almost dead short to the amplifier/s.

Joe

560sec_vroom - 12/23/2005 5:02 PM

I have pretty much confirmed the stock system uses 2ohm speakers and the series wiring method wont work unless you add 2 more speakers and sperate into 2 speakers for front group and 2 speakers for rear group. Also the 10 speaker designation is a little missleading they are calling each or the rear deck speakers as seperates 3 each side giving 6 rear 2 door 2 dash. But rears have one signal suppy and uses resitors or crossovers to sepearte signal to the 3. So you can cosider it more accuratly a 3 way speaker.
Doug

PS I am still trying to find out if there is a sipmple cheap way to increase resistance.

 

[560sec_vroom]

Well I always thought if you used speakers with to low resitance it put to much heat into the amp.
As far as adding speakers I figure in that case might just as well replace the stock speakers with after market 4 ohm.

I thought what you said about about the restance would be the case, I have used resistors before to filter frequency like a high pass low pass of an amp.

Doug

 

[jbleaux]

Doug,

You cannot use resistors alone to make a crossover or filter network. To do this requires a coil/transformer with its own impedance at certain frequencies. It can also be made with a capacitor, resistors and coil. This circuit has a 'time-constant' but I am getting off on a tangent and this is not helping you.


Designing a proper, efficient crossover network is beyond the scope of what we can do here or is it needed for what you are trying to accomplish.

Further, just to say and view it correctly, too low of an impedance or resistive load does not PUT heat into the amp. That will cause the output transistors in the amplifier to run beyond their design parameters and cause THEM to overheat.

As you probably know, you need to know the impedance or 'output' impedance the amplifier expects to see and configure your speaker system according to that.
By using various series or parallel or series/parallel combinations, you can come very close to what the amplifier wants.

If you will tell me what (0hms) speakers you want to install both in the front and the rear and the amplifier impedance, I will tell you the electrical configuration.

Joe

560sec_vroom - 12/24/2005 2:46 PM

Well I always thought if you used speakers with to low resitance it put to much heat into the amp.
As far as adding speakers I figure in that case might just as well replace the stock speakers with after market 4 ohm.

I thought what you said about about the restance would be the case, I have used resistors before to filter frequency like a high pass low pass of an amp.

Doug