If you are presently using the amplifier's 8 ohm tap, corresponding to the rated nominal impedance of the speaker, try the 4 ohm tap.
I have no particular familiarity with the Boxer, and I couldn't readily find any info on how its impedance varies as a function of frequency. But many small two-way speakers have a considerably lower impedance in the bass region than at higher frequencies, the expectation being that the interaction of that kind of impedance characteristic with the near zero output impedance of most solid state amplifiers will result, for a given signal level, in increased power delivery at low frequencies, relative to power delivery at high frequencies. Thereby compensating to some extent for the limited bass capability that a small two-way will tend to have.
That increase in low frequency power delivery will not occur to the same degree with a tube amplifier, due to its relatively high output impedance. But the output impedance of the 4 ohm tap will be significantly less than for the 8 ohm tap.
If that doesn't help sufficiently, room acoustics, speaker placement, and the direction in which the speakers are aimed would probably be what I would focus on next. For one thing, if they are presently aimed at the listening position try aiming them straight ahead.
Regards,
-- Al
I have no particular familiarity with the Boxer, and I couldn't readily find any info on how its impedance varies as a function of frequency. But many small two-way speakers have a considerably lower impedance in the bass region than at higher frequencies, the expectation being that the interaction of that kind of impedance characteristic with the near zero output impedance of most solid state amplifiers will result, for a given signal level, in increased power delivery at low frequencies, relative to power delivery at high frequencies. Thereby compensating to some extent for the limited bass capability that a small two-way will tend to have.
That increase in low frequency power delivery will not occur to the same degree with a tube amplifier, due to its relatively high output impedance. But the output impedance of the 4 ohm tap will be significantly less than for the 8 ohm tap.
If that doesn't help sufficiently, room acoustics, speaker placement, and the direction in which the speakers are aimed would probably be what I would focus on next. For one thing, if they are presently aimed at the listening position try aiming them straight ahead.
Regards,
-- Al