Hi, is a frontfire subwoofer a better and more powerfull (pushes more air into the room) subwoofer setup then a downfire ?
I ask this because all the "big" subwoofer brands use frontfire.
The brands that look to optical solutions use often downfire or something else then frontfire.
Yes, no and it depends
The reason most subwoofers or "front firing" or positioned so the cone is hornizontal has to do with gravity. Take a suboowfer and point the cone at the ground and notice that the cone moves down--gravity must be obeyed. The cone/voice coil assembly will move downward which can do several things. The first one is lt limits Xmax, if the cone is rated for say 15mm of Xmax (cone movement in one direction) and it naturally sags say 2mm when pointing downwards or upwards, your new "Xmax" is now 13mm moving "down" and 17mm moving "up". In reality, you just lost 2mm of Xmax. If you want to get OCD about it, this now makes the subwoofer "harder" to move in one direction (up) than the other direction (down) because of gravity assist.
In reality, does it matter? That depends on the design of the subwoofer, you need a fairly stout "motor" or your magnet/voice coil assembly to prevent gravity from pulling it down more than 5 percent. Some subwoofers can do it, others can't so the "sag" depends on the manufacturer of the subwoofer. If you build you own, some companies will supply that information. The Dayton Audio Ultimax subs have less than 5% sag for instance, they work fine when pointed down or up. Other subwoofers won't, it depends on the design.
Do downfiring subs sound "better" than subs monted conventionally on their sides? It is not that simple, plenty of other, far more important things to deal with than orientation of the subwoofer drivers.
If you go completely OCD and the last nth degree--front firing will give better performance because of the slightly more usuable Xmax--however, if you "need" that last 5% of Xmax to make an actual difference, then you really need more subwoofers because pushing subs to the edge of tolerances on a normal basis is a poor design at the start.
There are many factors in subwoofer design with orientation of the driver being just one of them. Some designs that allow more performance being down firing (limited height for instance) will perform better than using a lower performance subwoofer on edge because of height constraints. There is a method to the madness!
The same issue happens with ports, front firing, rear firing, side firing (includes passive radiator subs) and even top firing ports on 8 foot tall cylinder shaped subwoofers--it depends on your use.
As a generic answer, if you can, put them as "horizontal firing" or the speaker driver on edge if you can. My grandmother told me gravity always wins (don't ask) so to prevent cone sag, put it on edge. A subwoofer I built uses a very heavy passive radiator that has a moving assembly weighing over 1 kilogram (2.2 pounds) Every four years I remove the beast and rotate it 180 degrees because there will be cone sag even when on edge. Not much of a concern with speaker drivers but very heavy passive radiators can sag even on edge. I rotate them every election cycle to counter passive radiator sag. This is why 99% of all passive radiators are horizontal firing, to prevent serious sag when placed vertical (I will never purchase a passive radiator type speaker/sub that uses horizontal firing because gravity always wins--poor design)
In summation, if the driver is designed to have less than 5% of it's linear movement (Xmax) donated to gravity--it can be used horizontal or vertical. If you can get a better performing subwoofer that is downfiring VS sidefiring--get the downfiring sub! All things being equal (in fairy land!) the horizontal configuration is "better" if you have to have an exact answer. In reality, there are many other factors in play so either/or will work and it depends on your needs. Downfiring is great if you want to disguise your subwoofer as an "end table". It is hard to believe but some spouses don't like the look of gaint speaker cones or grills (heresy!) Rumor has it, in the real world--many people don't like the idea of giant boxes, huge cones and ports--so use whatever hines your hobby best so you can get the best performance in the available space.
For the record, I have used downfiring subs, used "upfiring" subs in cars and how have all "side firing" subs for my HT and garage sound systems. Some of my best friends have downfiring subs!
Hope that helped more than it hurt--use whatever fixes your other issues first before worrying about up or side firing--all part of the fun! Enjoy and have a great weekend.