Since this has not been mentioned:
The first thing to check is the phase!!
Try swapping the red for black connections on the back of the speaker (one channel only), put on a record with some bass impact and see if the bass is better or worse. If the speaker is out of phase bass will be poor and with some speakers and some rooms you may not notice that the imaging isn’t what its supposed to be. So it might be that the imaging will improve as well if phase is a problem.
Another thing that can cause loss of bass is the length of the speaker cables. One advantage to running monoblocks is the ability to place the amps close to the speaker to allow you to minimize the length of the speaker cable. This usually has a bigger effect with tube amps than solid state due to the output impedance of the tube amps being higher. This is exacerbated if the bass region of the speaker is 4 ohms instead of 8 or 16!! Generally speaking a meter and a half is the upper limit with nearly all tube amps unless you have 16 ohm speakers and you don’t. If your speakers are 4 ohms the limit is more like one meter and the cables had better be pretty heavy.
Its also important to make sure the connections on the amps and speakers are as tight as possible. DO NOT OVERTIGHTEN or you might really regret it.
You may also be experiencing a standing wave in the room; often a problem when the room has regular dimensions. If this is the case no amount of EQ will fix it. I advise staying away from EQ as you will find that the EQ exacts a price which is a loss of transparency and musicality. Its better to find a solution by other means. A standing wave can often be cured by moving the speaker somewhat. If you are stuck with the location, back the speaker up as much as you can and fiddle with toe-in.
Of the subwoofer suggestions, I second the Swarm made by Audiokinesis, should you find that subs are indicated.
The first thing to check is the phase!!
Try swapping the red for black connections on the back of the speaker (one channel only), put on a record with some bass impact and see if the bass is better or worse. If the speaker is out of phase bass will be poor and with some speakers and some rooms you may not notice that the imaging isn’t what its supposed to be. So it might be that the imaging will improve as well if phase is a problem.
Another thing that can cause loss of bass is the length of the speaker cables. One advantage to running monoblocks is the ability to place the amps close to the speaker to allow you to minimize the length of the speaker cable. This usually has a bigger effect with tube amps than solid state due to the output impedance of the tube amps being higher. This is exacerbated if the bass region of the speaker is 4 ohms instead of 8 or 16!! Generally speaking a meter and a half is the upper limit with nearly all tube amps unless you have 16 ohm speakers and you don’t. If your speakers are 4 ohms the limit is more like one meter and the cables had better be pretty heavy.
Its also important to make sure the connections on the amps and speakers are as tight as possible. DO NOT OVERTIGHTEN or you might really regret it.
You may also be experiencing a standing wave in the room; often a problem when the room has regular dimensions. If this is the case no amount of EQ will fix it. I advise staying away from EQ as you will find that the EQ exacts a price which is a loss of transparency and musicality. Its better to find a solution by other means. A standing wave can often be cured by moving the speaker somewhat. If you are stuck with the location, back the speaker up as much as you can and fiddle with toe-in.
Of the subwoofer suggestions, I second the Swarm made by Audiokinesis, should you find that subs are indicated.