Is there any sonic difference between the chips that people have observed? Other than that some are louder than others...
At your +/-23vdc you're in the middle of the range with STK459/460, so any difference would be approximately 1db at the speaker. The STK461, which also works on that voltage may have a very slight difference.
There's a slight problem in that you need a bigger job done than the chip can do.
For doing a bigger job safely:
If you wanted to play a Lot louder without explode, then you'd like to bi-amp, which is where the stk plays only midrange and treble, with the passive crossover making for a Very light load (the stk is not loaded for bass work), and then an added sturdy amplifier for pushing the woofer, considerably. Sure bi-amp is more expensive and double the wires, but it is hugely effective.
Comparisons:
With my TDA7293 Parallel amp, and Not using the datasheet sample schema but only if using the published mods, it achieves 90W and a tone similar to my STK459.
Lets see how many decibels that is:
(if the speaker is 87db efficient)
1W, 87DB
2W, 90DB
4W, 93DB
8W, 96DB
16W, 99DB
23W, 100.5DB, STK459's 23W
32W, 102DB
48W, 103.5DB, One TDA7293 (limiter action at ~45W)
64W, 105DB
96W, 106.5DB, TDA7293 Parallel (limiter action at ~90W)
128W, 108DB, easily doable with Honey Badger discrete amp
192W, 109.5DB, possible with Honey Badger and MJL21193, MJL21194
*The above is the output of one speaker
The inexpensive way:
You can tell by watts versus decibels, that when you turn an amplifier up to get a much louder output, you might be asking it to do the job of a far larger amplifier.
That could be done a little safer with some more protection added, such as the simple inexpensive LTP soft clipper circuit. It involves one multi-turn trimmer (replaces fb-shunt resistor with same value trimmer, configured as potentiometer, not a variable resistor), an inversely paralleled pair of tiny low-capacitance diodes (hooks up between the trimmer's wiper and 330R) and that 330 ohm resistor connects to in+. Soft clippers do cause clipping, so this one's benefit is limited to clipping the input quickly and gently instead of much louder sticking outputs clipping (high-current clipping can blow up the outputs). The soft clipper is really only "soft" in that the duration, current and intensity of clip is less than the alternative of going without it. I mention this because it seems that you already know how much it takes to blow the outputs, so it should be possible to dial in the LTP soft clipper to less than that much. Unexpected additional function: In some cases, it is possible to adjust the 330R (change value) to fine tune imaging/soundstage/tone, a little bit. Expected function: The main usefulness occurs when you've got varying track amplitude at the bass and when the amp is at full blast, so then the next track that has more bass doesn't blow the outputs. Sure, it would be a LOT better to bi-amp, but the LTP soft clipper is much cheaper and more compact. Unlike bi-amp, soft clipper doesn't do a bigger job at all.
There's a slight problem in that you need a bigger job done than the chip can do.
For doing a bigger job safely:
If you wanted to play a Lot louder without explode, then you'd like to bi-amp, which is where the stk plays only midrange and treble, with the passive crossover making for a Very light load (the stk is not loaded for bass work), and then an added sturdy amplifier for pushing the woofer, considerably. Sure bi-amp is more expensive and double the wires, but it is hugely effective.
Comparisons:
With my TDA7293 Parallel amp, and Not using the datasheet sample schema but only if using the published mods, it achieves 90W and a tone similar to my STK459.
Lets see how many decibels that is:
(if the speaker is 87db efficient)
1W, 87DB
2W, 90DB
4W, 93DB
8W, 96DB
16W, 99DB
23W, 100.5DB, STK459's 23W
32W, 102DB
48W, 103.5DB, One TDA7293 (limiter action at ~45W)
64W, 105DB
96W, 106.5DB, TDA7293 Parallel (limiter action at ~90W)
128W, 108DB, easily doable with Honey Badger discrete amp
192W, 109.5DB, possible with Honey Badger and MJL21193, MJL21194
*The above is the output of one speaker
The inexpensive way:
You can tell by watts versus decibels, that when you turn an amplifier up to get a much louder output, you might be asking it to do the job of a far larger amplifier.
That could be done a little safer with some more protection added, such as the simple inexpensive LTP soft clipper circuit. It involves one multi-turn trimmer (replaces fb-shunt resistor with same value trimmer, configured as potentiometer, not a variable resistor), an inversely paralleled pair of tiny low-capacitance diodes (hooks up between the trimmer's wiper and 330R) and that 330 ohm resistor connects to in+. Soft clippers do cause clipping, so this one's benefit is limited to clipping the input quickly and gently instead of much louder sticking outputs clipping (high-current clipping can blow up the outputs). The soft clipper is really only "soft" in that the duration, current and intensity of clip is less than the alternative of going without it. I mention this because it seems that you already know how much it takes to blow the outputs, so it should be possible to dial in the LTP soft clipper to less than that much. Unexpected additional function: In some cases, it is possible to adjust the 330R (change value) to fine tune imaging/soundstage/tone, a little bit. Expected function: The main usefulness occurs when you've got varying track amplitude at the bass and when the amp is at full blast, so then the next track that has more bass doesn't blow the outputs. Sure, it would be a LOT better to bi-amp, but the LTP soft clipper is much cheaper and more compact. Unlike bi-amp, soft clipper doesn't do a bigger job at all.
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