Poll: Which option will provide the best sound quality?
Poll Options
View poll results: Which option will provide the best sound quality?
16 Speakers (4 Ohm) - 4 Parallel CABs of 4 Speakers each in Series
0 0%
8 Speakers (8 Ohm) - 4 Parallel CABs of 2 Speakers each in Series
0 0%
4 Speakers (4 Ohm) - 2 Parallel CABs of 2 Speakers each in Series
1 100%
2 Speakers (8 Ohm) - 2 Parallel CABs of 1 Speaker each
0 0%
Other Option
0 0%
Voters: 1.
#1
I am considering building a cabinet. I have a 6 different simple CAB configurations.

However, I was wondering what the effect of building a cabinet capable of producing more power than the head is capable of outputting.

For example...

Assume the Amplifier Head has a single 4 ohm, 100 W output.

Here are 4 possible configurations

16 - 60W speakers, all 4 ohm, 4 parallel cabs of 4 speakers each in series
-- Total CAB power is 960W
---- This implies each speaker receives ~6.25W (~10% of speaker capability)

or

8 - 60W speakers, all 8 ohm, 4 parallel cabs of 2 speakers each in series
-- Total CAB power is 480W
---- This implies each speaker receives ~12.5W (~20% of speaker capability)

or

4 - 60W speakers, all 4 ohm, 2 parallel cabs of 2 speakers each in series
-- Total CAB power is 240W
---- This implies each speaker receives ~25W (~40% of speaker capability)

or

2 - 60W speakers, all 8 ohm, 2 parallel cabs of 1 speakers each
-- Total CAB power is 120W
---- This implies each speaker receives ~50W (~80% of speaker capability)

Basically the question is, at what point does being excessively underpowered at the amp become a sound quality issue?
#2
Basically the question is, at what point does being excessively underpowered at the amp become a sound quality issue?

It doesn't, unless you really like your speaker distortion at high power - which you won't get.

Really it's best to match them fairly closely.

Trad 4x12 cabs had 4 off 25w or 30w speakers in series / parallel. (This was when power was measured in real watts not the shit you have nowadays)

So 100W amp could distort the speaker output about 10 or 20% at high power.

100W valve amp + a 4 x 12 is the loudest you would ever need btw - unless you are playing massive venues without being mic'd up to a PA system.
#3
What I am reading here is if the available speaker input power is 10W, the closer to 10W you are the more the speaker sounds distorted. Right? Never go under, but over is ok?


I have also read that the speaker power capability should be double the supplied power. Would that mean if input power is 10W, a 20W speaker should be used?
#4
Most amp power is dissipated as heat. Speaker power ratings tell you how much heat the voice coils can take before they warp, etc.
You don't even want to think about speaker distortion in this day and age; it was a thing in the '60's, before guitarists realized that they were paying a lot for reconing and new speakers. It's a relic from the days when guitarists used to take a knife to their speaker cones to make them sound buzzy. Stupid then, worse now.

Speaker power ratings should, at a minimum, match the nominal output of the amp. If you've got more than one speaker in the cabinet, multiply the power rating of the lowest rating by the number of speakers you have to see if you've got enough. Modern speakers are generally capable of handing more power than indicated by their ratings; if a 100W rated tube amp is actually putting out 200W when driven into max power tube distortion, a 100W speaker (or group of them) will generally handle the overage.

Sound quality due to underpowered amps becomes a liability when you can't get low end out of the speakers that isn't muddy. The old saw with a 100W Marshall stack is that as the volume goes up, the bottom disappears. It takes four times as much power to reproduce a note an octave down at the same volume as the original note. Guitar players have built whole powered subwoofer systems (see the ISP Technologies Vector SL) to augment their stacks. In the case of the Vector SL, a single 15" subwoofer speaker has its own 600W power amp and a sophisticated electronic system to strip and redirect the low end from the tube amp's output.