If you are using a tweeter with an efficiency of 100 dB/W or higher

I drive my 3-way speaker with multi-amp setup.

The tweeter has an efficiency of 109 dB/W.
Initially, when I was driving the tweeter with a regular AB class transistor amplifier,
I could still hear the residual noise from the amplifier even when I turned the master volume to zero.

Therefore, I switched to a headphone amplifier with 0.7W+0.7W (32 Ω load),
and the noise completely disappeared.
The tweeter's high efficiency provides sufficient volume, so there is no need for concern about the sound level.

Using a headphone amplifier for driving the tweeter is effective.
Do you have any reservations about using a headphone amplifier to drive the tweeter?
 
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I switched to a headphone amplifier with 0.7W+0.7W (32 Ω load),

Do you have any reservations about using a headphone amplifier to drive the tweeter?
What is the impedance of the tweeter? If significantly below the rating of the amp, that could lead to more distortion or less power available, but it's amp and speaker dependent so hard to say for sure.

You may get the same benefit by using a conventional amp with lower gain than usual.

To reduce hiss, some people use a L-pad on the tweeter to bring the sensitivity down to a more typical level.
 
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Thanks' mattstat

The impedance of the tweeter is 8 ohms. The crossover frequency is 700 Hz and the roll-off is 48 dB/octave.
The dimensions of the room are 3.6m x 3.6m x 2.4m.
In preparation for testing a headphone amplifier,
I observed the terminal voltage of the tweeter with an oscilloscope when it was playing at the maximum sound level
my ears could withstand while listening to Beethoven's Symphony.
The peak maximum was 15mW in terms of power conversion.
Therefore, I considered that 0.7W was more than sufficient margin.

One of the advantages of multi-amp drive is that there is no need for resistors, coils, capacitors, or
other components between the amplifier and speaker unit.
Therefore, using an L-pad seems like a method of
"straightening a corner, killing a bull's strength", which is a Japanese proverb.
In Western, the equivalent proverb would be "throwing the baby out with the bathwater".
 
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