My guess is that one panel will make no or just barely perceptible audible difference in the bass unless it is in the corner and you are physically less than three feet from it.
I think that two panels and you will just begin to hear improvements (barely).
I would say that four panels and you have a modest improvement in most rooms (worthwhile but not a total cure). I would think you need to be up around 8 panels to make a serious impact.
If you go membrane or resonators such as tubes rather than broadband absorbers then provided you know what you are doing then you can get the same benefit (at a specific frequency) for 1/4 the treatment. So two membrane panels tuned to your specific problem might be as effective as 8 broadband minitraps.
The disadvantage of "tuned resonators" is that they don't help as much outside their "tuned" range. So in my mind broadband bass trapping is the way to go if you can find an aesthetic solution that is acceptable.
This is all "rule of thumb" YMMV but in the case of acoustics size actually does matter.
I think that two panels and you will just begin to hear improvements (barely).
I would say that four panels and you have a modest improvement in most rooms (worthwhile but not a total cure). I would think you need to be up around 8 panels to make a serious impact.
If you go membrane or resonators such as tubes rather than broadband absorbers then provided you know what you are doing then you can get the same benefit (at a specific frequency) for 1/4 the treatment. So two membrane panels tuned to your specific problem might be as effective as 8 broadband minitraps.
The disadvantage of "tuned resonators" is that they don't help as much outside their "tuned" range. So in my mind broadband bass trapping is the way to go if you can find an aesthetic solution that is acceptable.
This is all "rule of thumb" YMMV but in the case of acoustics size actually does matter.