I may be an idiot... but is under-powering a load of ballcocks?

[Guest monsterthompson]

[quote name='Chienmortbb' timestamp='1410430931' post='2549313']
if you bridge an amp you will get 3-6db more power output at the same settings on the preamp comlared to a single channel.
[/quote] right. which is why i'd turn the output down when bridged. I think the issue was more to do with the burst power and available headroom of the extra wattage. for the same output levels (to my ears) the bridged settings "felt" more muscular. Since the volume knob isn't a direct wattage control, it's hard to know exactly what was happening, but I'd hazard a guess that bridge setting gives you more oomph in reserve for transients.

[Dad3353]

Clipping [i]is [/i]DC, alternating between +ve and -ve at a certain frequency. For a period of time, the speaker sees a constant potential, which suddenly reverses polarity. Yes, it's alternating, but just as damaging as DC in the constant polarity sense. Speakers are happy when they're moving. They don't like being pinned up against one end of their travel or the other.

Edited September 11, 2014 by Dad3353

[Bill Fitzmaurice]

[quote name='Dad3353' timestamp='1410457166' post='2549689']
Clipping [i]is [/i]DC, alternating between +ve and -ve at a certain frequency. For a period of time, the speaker sees a constant potential, which suddenly reverses polarity. Yes, it's alternating, but just as damaging as DC in the constant polarity sense. Speakers are happy when they're moving. They don't like being pinned up against one end of their travel or the other.
[/quote]None of that is true. Read the QSC link that I posted. The author is not only an applications engineer at QSC but also a past Secretary of the AES. Whatever sources you got your information from are simply incorrect.

[Dad3353]

[quote name='Bill Fitzmaurice' timestamp='1410460706' post='2549751']
None of that is true. Read the QSC link that I posted. The author is not only an applications engineer at QSC but also a past Secretary of the AES. Whatever sources you got your information from are simply incorrect.
[/quote]

Ah. So a square wave with a period of 20 years is not the same as DC to a speaker..? OK.

I wasn't trying to be academically correct, I was trying to explain that speakers can fry under square waves. Sorry if there's a lack of purist content. [size=4] [/size]

[Magic Matt]

[quote name='Dad3353' timestamp='1410457166' post='2549689']
Clipping [i]is [/i]DC, a
[/quote]

No, it really isn't.

[quote name='Dad3353' timestamp='1410457166' post='2549689']
Speakers are happy when they're moving. They don't like being pinned up against one end of their travel or the other.
[/quote]

I've never managed to "pin" a speaker, or burn one out for that matter, with intentional application of DC (with the exception of exceeding speaker power ratings obviously). I'm not convinced you can actually pin them.

[quote]
[color=#282828][font=helvetica, arial, sans-serif]Ah. So a square wave with a period of 20 years is not the same as DC to a speaker..? OK[/font][/color]
[color=#282828][font=helvetica, arial, sans-serif][/quote][/font][/color]


Feel free to try it.

[dincz]

[quote name='Magic Matt' timestamp='1410456160' post='2549674']
Read the comment about clipping being DC and cracked up! LOL! How could anyone think clipping is D.C.!?!?
[/quote]

I think it's because if you look at it for a short enough time period, it is DC. Not correct but understandable.

Edited September 12, 2014 by dincz

[dincz]

[quote name='Dad3353' timestamp='1410461034' post='2549762']
Ah. So a square wave with a period of 20 years is not the same as DC to a speaker..?[/quote]

That's why I avoid drop tuning

[Magic Matt]

[quote name='dincz' timestamp='1410513603' post='2550174']
That's why I avoid drop tuning
[/quote]

So you'd have to remove the highpass protection filter... how would you stop the gravitational influence of the moon affecting your signal?

[dincz]

[quote name='Magic Matt' timestamp='1410522115' post='2550306']
So you'd have to remove the highpass protection filter... how would you stop the gravitational influence of the moon affecting your signal?
[/quote]

I'd leave it as is. Prefer a natural, organic sound

[xgsjx]

[quote name='Magic Matt' timestamp='1410522115' post='2550306']
So you'd have to remove the highpass protection filter... how would you stop the gravitational influence of the moon affecting your signal?
[/quote]
Or you could just play during the day.

[Dad3353]

[quote name='xgsjx' timestamp='1410553603' post='2550812']
Or you could just play during the day.
[/quote]

The moon is often in the sky during the day; we just don't see it, outshone by the sun. This may explain some daytime concerts having such lousy bass sound..? [size=4] [/size]

[tauzero]

[quote name='HowieBass' timestamp='1410389229' post='2549045']
I think he means 'harmonics that are lower in volume than that of the fundamental frequency of the square wave'.
[/quote]

A square wave is actually made up of a series of sine waves, all the odd harmonics of the signal. The amplitude of each harmonic is inversely proportional to its harmonic relationship, so if the fundamental is 1V p-p, the 3rd harmonic will be 1/3V p-p, the 5th harmonic will be 1/5V p-p, the 7th harmonic 1/7V p-p, and so [i]ad infinitum[/i]. I once built a square wave generator using a TTL IC, so it was providing 5V p-p, tuned to about 1kHz, and it would happily radiate into the RF range.

[HowieBass]

[quote name='tauzero' timestamp='1412205180' post='2566835']
A square wave is actually made up of a series of sine waves, all the odd harmonics of the signal. The amplitude of each harmonic is inversely proportional to its harmonic relationship, so if the fundamental is 1V p-p, the 3rd harmonic will be 1/3V p-p, the 5th harmonic will be 1/5V p-p, the 7th harmonic 1/7V p-p, and so [i]ad infinitum[/i]. I once built a square wave generator using a TTL IC, so it was providing 5V p-p, tuned to about 1kHz, and it would happily radiate into the RF range.
[/quote]

Yeah I think I first learned about Fourier Series when I did A Level physics though I've never used that knowledge in any practical setting - what was your signal generator for?

[tauzero]

[quote name='HowieBass' timestamp='1412206307' post='2566841']
Yeah I think I first learned about Fourier Series when I did A Level physics though I've never used that knowledge in any practical setting - what was your signal generator for?
[/quote]

Just testing audio pathways. It was a signal injector, I remember now - a 7400 IC, the odd capacitor and resistor, all on a bit of veroboard in a 35mm film container with a length of threaded rod sticking out of it. This was 40 years ago so it's a bit of a struggle remembering, especially these days when breakfast is a bit of a mystery.

I also wrote a program for a Sinclair QL which built up a display of a square wave from the harmonics.