How to tell (+) or (-) on Weber speaker

[chcjunior]

if it's not marked as such? The only distinction between the two terminals is one is marked red. I'm assuming this is the positive? I need to wire the speaker to an input jack so I can do the testing round on the amp I'm building.

 

[the guy who invented fire]

Re: How to tell (+) or (-) on Weber speaker

The red mark should be the positive terminal but FWIW...one of my Webers in actually marked backwards!

Do the 9 volt battery test...

 

[chcjunior]

Re: How to tell (+) or (-) on Weber speaker

The red mark should be the positive terminal but FWIW...one of my Webers in actually marked backwards!

Do the 9 volt battery test...

Which leads to a new question; what exactly is the 9 volt battery test?

 

[Lewguitar]

Re: How to tell (+) or (-) on Weber speaker

The red mark should be the positive terminal but FWIW...one of my Webers in actually marked backwards!

Do the 9 volt battery test...

So if plus on the battery is connected to plus on the speaker (and minus to minus) the speaker cone moves out...right?

Lew

 

[Mike M.]

Re: How to tell (+) or (-) on Weber speaker

I have an additional question. How can you tell what the ohmage of a speaker is that isn't marked? I have two old Gauss 12" speakers that I've had since the late 70's that have no info on them pertaining to ohms. I have'nt used them in years and I don't want to blow them up. Thanks.

 

[the guy who invented fire]

Re: How to tell (+) or (-) on Weber speaker

So if plus on the battery is connected to plus on the speaker (and minus to minus) the speaker cone moves out...right?

Lew

My bad...thats right.

Set the speaker up so you can watch the cone move (it's a VER small amount of movement so watch closley) if you touch the battery + to the + of the speaker and the battery - to the - of the speaker the cone willmove out from the magnet if you touch the battery "backwards" the cone will move in. That will tell you which is positive and which is negative.

As for reading the impedence, hit the terminals with a vole meter set to ohms that will show you the resistance of the voice coil which = the impedence.

 

[D-EJ915]

Re: How to tell (+) or (-) on Weber speaker

Sometimes the negative terminal is also smaller than the positive one.

 

[chcjunior]

Re: How to tell (+) or (-) on Weber speaker

Good info all around...thanks! Now let me see if this kit actually works.

 

[Rich_S]

Re: How to tell (+) or (-) on Weber speaker

As for reading the impedence, hit the terminals with a vole meter set to ohms that will show you the resistance of the voice coil which = the impedence.

This answer is close; just like DVM reading ohms will read close to the speaker's rated impedance. A DVM reads DC resistance, which will be lower than a speaker's total impedance. For example, my 8-ohm Celestion G12H80 reads 7 ohms on my Fluke meter.

A 4-ohm speaker will probably read between 3 and 4 ohms. A 16-ohm speaker will read about 15 ohms. You get the idea. It's not exact, but it close enough to tell them apart.

 

[D-EJ915]

Re: How to tell (+) or (-) on Weber speaker

Also that resistance varies with frequency, usually there's an impedance bump at the low end and then "normals" at whatever they rate it to and goes off to infinity as frequency goes to infinity.