I'm not familiar with the Nighthawks, so I can't respond directly to your query. However, I am curious about your comment that your 3A Sig's seem to lack tight bass. I also own the 3A Sig's (plus a pair of 2Wq subs), and I would not characterize the 3A Sig's as having loose bass.
The dimensions of your listening room seem good for your Vandies, so there could be two possible factors that explain your sense that the 3A Sig's lack tight bass:
1. rooms that are constructed with dry wall over studs, or having a crawl space below the floor, can often be resonant, thereby making the bass sound boomy or loose;
2. amplifiers with inadequate power reserves, or low damping factor, may lack adequate bass control.
If either of the two factors I just outlined are true for your system, you may find that ANY dynamic speaker will sound somewhat loose.
It would be helpful to have a description of your system and your listening room. Before you sell your 3A Sig's, it would be a good idea to determine if the loose bass you are hearing is due to the room or the amp. By all means, check out the Nighthawks (Meadowlark is one of the very few companies other than Vandersteen that make time-accurate and phase-correct speakers), but since you like your Vandies you might consider adding a pair of 2Wq subs. I found that having a pair of 2Wq's not only make a significant improvement in the low frequency reproduction, but also yielded better mid-range transparency and dynamic response.
The dimensions of your listening room seem good for your Vandies, so there could be two possible factors that explain your sense that the 3A Sig's lack tight bass:
1. rooms that are constructed with dry wall over studs, or having a crawl space below the floor, can often be resonant, thereby making the bass sound boomy or loose;
2. amplifiers with inadequate power reserves, or low damping factor, may lack adequate bass control.
If either of the two factors I just outlined are true for your system, you may find that ANY dynamic speaker will sound somewhat loose.
It would be helpful to have a description of your system and your listening room. Before you sell your 3A Sig's, it would be a good idea to determine if the loose bass you are hearing is due to the room or the amp. By all means, check out the Nighthawks (Meadowlark is one of the very few companies other than Vandersteen that make time-accurate and phase-correct speakers), but since you like your Vandies you might consider adding a pair of 2Wq subs. I found that having a pair of 2Wq's not only make a significant improvement in the low frequency reproduction, but also yielded better mid-range transparency and dynamic response.