speaker impedance

[aero_91]

can i know what is this speaker impedance all about in layman terms? i've searched the net and don't really understand. been thinking about replacing speakers on my cabinet, but do i choose 8ohm or 16ohm?

 

[Ratboy]

simplistically,
impedance is a measure of how easy a/c current can flow thru the speaker
If you are replacing 1 for 1 , you should just get back the same impedance


if you under spec your impedance,
( say orginal impedance is 8ohms and u replace with a 2 ohm speaker )
this will cause greater flow of current
which the amp may not be designed for = "bye bye amp"

if you over spec your impedance,
( say orginal impedance is 8ohms and u replace with a 16 ohm speaker )
this will cause underflow of current
= lower output, sound is compromised.

Tube equipment can take bigger mismatch
solid state stuff are more sensitive
but best not to mismatch

 

[lightice]

Not exactly, should you not be able to find a speaker that matches the impedance of the amp's OT.

These are the guidelines.

Mismatch is allowed 1 step up or down.

Up: Speaker impedance more than OT impedance
Down: Speaker impedance lower than OT impedance

Tube amps: Down
SS amps: Up

If you need to find out the current impedance of your speaker, use a multimeter, set it to ohms and put it on the +ve and -ve of the speaker

If its 16ohms, you'd get around 15ohms reading
If its 8ohms, you'd get around 7ohms reading

 

[aero_91]

i still dont really get it. if now the speakers are at 8ohm, what will happen to the tone if i change all 4 to 16ohm?

i also read up something about the speakers in parallel and series. so, will the impedance affect the loudness and tone?

im using a full tube orange ad30htc by the way

 

[lightice]

You will need to know some basic physics regarding wiring up resistances in parallel or series.

You'd want the total impedance, not the individual of each speaker.

You need to see what impedance your amp's OT can handle. Then wire the 4 speakers up to that.

 

[aero_91]

i know that. i studying physics in jc2 now. so basically, impedance is just resistance?

 

[mus]

Since you study physics,

Impedence is not Resistance.

Let's look at the formula,

Resistance (R) = V/I

Impedence (Z) = R + jX

Since resistors, inductors and capacitors present, the output value is impedence.

That's just to confuse you. :mrgreen:

This link should help,

http://soft.com.sg/forum/gear-guitar/90968-calculating-speaker-impedance.html

 

[lightice]

Not the same, but both use the same formula to calculate series and parallel.