cutting low end in the ruby (a lot)

[birt]

since i want to use this circuit with a very very small speaker (2,5-4cm / 1-1,5") i think in need to get rid of a lot of the low end in the amplified signal.
i think it's that low end that makes these tiny speakers flap and buzz until they break. my theory is that a telephone speaker can be really loud with a voice coming from a telephone but you can't get it to be loud with a guitar without buzz.

is this nonsense? and if not, how can i shape the already amplified signal coming from a ruby amp?

[the_random_hero]

Lower the input cap.

[GibsonGM]

I think you're right, Birt...the frequencies coming from a guitar, with the harmonics generated thru the amplification and clipping in the Ruby, will encompass a lot more than the lower frequencies of speech.
+1, Random....Lowering the input cap will raise the frequencies fed to the Ruby (inversely proportional), and trim some of the by-products generated thru the amplification. 
Another quick fix is to lower the output cap, or try working with both for the best sound.   Input cap tends to control how 'mushy' the tone will be (clipping bass freq's tends to get muddy, bass is generally cut before clipping), and the output cap controls how 'telephone-like' the sound will be (or, how much bass you 'recover' after trimming it for amplification/clipping). 

[birt]

i thought i had a really good idea. why don't i measure the lowest frequency the speaker can handle.

so i hooked up an old (tube) sine wave generator to a small speaker and started with the lowest frequency on the generator. i could actually hear the 20Hz and the speaker wasn't clipping. one of the small speakers i tested clipped with some frequencies and i had to back of the voltage a bit but most just handled every audible frequency. i was stunned.
the outputvoltage of the generator varied from 1.5V up to 10V (max output) depending on the frequency tough. only the highest frequencies were 10V. they were also the loudest.

so why do those speakers clip and break with guitar signal and reamain just fine with every frequency coming from this generator? i have no clue.

[the_random_hero]

My guess would be that speakers can more easily handle a 'pure' sine wave rather than a wave that's going to be quickly changing in amplitude, frequency plus the additional harmonics that you get with a guitar signal.