How to identify positive and negative on a JBL 2408 diaphram

The larger terminal on the diaphragm is the positve.

I believe series.....hook a wire to the positive of one voice coil to the negative of the other.....with the remaining two wire that to the amp.....check on google to see if your amp is able to be bridged.....Most of the time on the bottom of the amp there will be a diagram or the the two outer speaker outs on the amp itself....let me knoe if this helps you...thanks

oh yes the JBL GTi W15GTI Mkll. this subwoofer is a dual 6 ohm voice coil subwoofer. This is impossible to run this sub alone and get 1 ohm you will need another JBL GTi W15kll. the lowest impedance you can go to is 3 ohms. you can achieve this by connecting the positive terminals together and then running a wire from the two positives to the positive terminal on the amp. then connecting the negative terminals together and then running a wire to the negative terminal on the amp. this is a real nice sub it just has that one down fall of having a six ohm voice coil.

Hi Adrian,
To be honest, it depends on your amp, also on whether this is a dual voice coil sub or a single.

As a rule, if the sub has a dual voice coil (2 sets of connections) then connect the 2 positives together and the 2 negatives and run the 2 sets of cables to one output on the amp.

Check your amp specs to make sure that it will run @ 2 Ohms as this is what will result.

If your amp isn't 2 Ohms stable then you will have to wire each voice coil to a separate output on the amp.

It is confusing with the 4 channels it gives you but you really only need to connect it to one or the other positive and negative terminals. The amps channel setup looks like this + - + - . You can connect to the first positive and negative, the second, or combine them. I had mine installed by a professional which is how I know. Also if you want to run your amp at 2 ohms then connect the subs voice coils in a parallel circuit which means that all positives are connected to each other and the same goes for the negatives. it should match the impedances of both sub and amp. Hope this helps!

Chainsaw carbs are all position pump carbs, and do have diaphrams, there will be a pump diaphram, and a metering diaphram, the pump diaphram pulsates via either a hole through the cylinder and induction block, or a pipe from the crankcase, the negative and a positive pressure produced as the piston rises and falls is fed into the carb, this diaphram shoud be flat show no signs of blistering or cracks, under this diaphram is the main inlet screen, this should be clean, any doubt and it should be replaced, the metering diaphram controls the amount of fuel allowed into the metering chamber, it should also lay flat and be supple, the metal disc in the middle should be flat and not distorted, both of these components are very robust and only need replacing if they are damaged, worn or have become stiff due to fuel attacking the material.

Make sure that your positives and negatives are lined up correctly. This happened to me during my latest install and the problem was I had one positive speaker wire plugged into a negative speaker terminal. This switches the amp on after a few seconds and then back to protect mode once it detects a faulty speaker wire. Hope this helps!

Running parallel means positive to positive and negative to negative.

Copper is positive, aluminum is negative. OR One of the wires should have a white (or black) stripe on the insulation...this is negative wire. OR If using 18 gauge extention cord wire, the positive wire will have small grooves running the entire lenght (very difficult to identify, unless you have good eyesight) Hope this helps.

ok, connect the amp positive to the positive end of one sub coil, take the negative of that coil, and run it to the positive of the second sub coil, then run the negative out of the second sub coil to the negative of the amp.