Use the right speakers, and this can be pretty easy. Here's what is in my Creature:

DSCN1359.JPG

The key is, get an efficient 8-ohm speaker.
http://www.mcmelectronics.com/product/MCM-AUDIO-SELECT-55-2950-/55-2950

The 94dB efficiency number means that it offers about 10x the sound output at the same power as a typical 84dB speaker. I install cheap car speakers in the head. You may need to fabricate spacers to stop the speaker surround hitting the wood.

so:
1) Replace cab speaker with efficient 8 ohm 8 inch speaker

2) rewire head so that cab is on one connector, and head on the other (this is easy, as they had to modify from this for the arrangement they ended up with).

3) Replace head speakers with 2 car speakers in series, eliminate capacitor.
If the head is then too strong, a sand resistor will fix that. 10 - 20 ohms usually seems about right. Order a small handful, tune to taste.

Excellent advice from Pam above. I like the 10 ohm resistor as well in backbox.

Visit Tony's page... More than you'll ever want/need.

http://www.dziedzic.us/wpc_speaker_wiring.html

Just extend those blue lines up to the connectors and you have it. That inline connector is up in the head. Split it, and run the wires to their respective connectors.

For the head, I usually buy cheap 51/4" car speakers. If you can find ones with recessed cones (not flush with the mounting flange) they don't need a spacer. Or, you can cut out the hole.

I have done this to three of my WPC games and it makes a world of difference

Great info here, I've used Tonys method a few times in the past.

Robert

Just to be accurate (and not meant as a threadcrap or insult at all):

a speaker that is 10dB more sensitive does mean it would take 1/10th the power to drive the more efficient speaker to the same level. However, let's say that one speaker is 84 dB/w/1m and one is 94 dB/w/1m. While the more efficient speaker will be outputting 94dB at 1 watt (at 1 meter), it will NOT sound 10x as loud. Sound is logarithmic, and as a consequence 10dB (10 times the power) is what we equate to sounding "twice" as loud. 3dB, which equates to a doubling of power only sounds "slightly" louder to the ear.