It is curious, but in many forums in different languages seems to be discussed this issue of problems derived from low frequencies. Without wishing to enter into discussions. Before believing in something even scientifically based, it is better to rely on and believe in one's own experience. In fact, because a person has studied in a particular field, it does not imply that he is an expert. Experts are born of experience, not of theory, or of the belief of physical or scientific laws. A good scientist tests things to be able to affirm them. This is just a comment, I'm not arguing with anyone.
Regarding my experience, I have very clear, because I rely on my experience, that a speaker with bass reflex reflex, is more difficult to orient than a loudspeaker with bass reflex front. The reason is that the speaker amplifies these lower frequencies to boost them. Then, it is necessary that the bass reflex is well calculated depending on the design (volume, distances, etc. from the acoustic box) to boost low frequencies properly and without problems (regardless if the bass reflex goes in front or back).
The fact is that studio monitors are thought to be more directional, especially at medium and high frequencies (more directional waves). But the low frequencies are still deep, and regardless of their size they are also directional, although the human ear has a harder time orienting itself with them, that hinder the fidelity of the composition. This is accentuated in smaller rooms, with the small desk, which is necessary to attach the speaker to the wall. Here it is best to avoid the speakers with bass reflex back, which is my case.
Therefore, it is not the same to place the bass reflex in front of it as in the back. Behind, the first trip that makes the back wave is towards the back wall and then rebounds (and expect the back wall to be vertical, not tilted). If you do not have your speakers well placed, you create a problem. This is as simple as picking up the speakers and placing them one meter from your head or almost on the ceiling. You will notice that basses are heard in a different way, and even depending on the room, they can get lost behind you or bounce and generate a bass ball, depending on the power at any given time. I am sure, because I have tried it myself, that speakers with bass reflex in front well designed are best solution for studio monitors in small rooms, not forgetting that it is necessary that the room is well conditioned.
So, ideal for studio monitors is to have all the waves frequencies being born in the same direction, oriented towards the composer, because it is in the interest of all, even the low frequencies, to travel as far as possible without bouncing up to their ears, and then Try the room or room so that the rebound waves do not reach the ears and generate redundant waves.
If you have a large room, and your desk separated by a few inches from the wall, you will be able to place speakers with bass refles back to 40 or 50cm from the wall, facing the composer, and you will receive low waves bounced off walls in a more centralized way, provided it is well acoustically conditioned. But these waves will bounce behind the composer in the same way. The theme is to keep the low waves from bouncing first on the back wall to bring it back to the composer, and this is difficult to resolve in the small rooms. So, it is not the same a small or large room, or it is not the same bass reflex behind that in front.
On the other hand, I wonder why this subject is still discussed in many forums. And the conclusion seems simple. Each room is a world, and every speaker is also. In the end, the experience in the same room is the best solution. Even if you go to a store to listen to some speakers, then in your room they may sound different, depending on their size and their acoustic conditioning. But hey, I'm no expert, I rely more on my own experience than on what a scientist says. More than anything, because the scientist can not enter my room .
Peace guys. Renoise is great !!!