Axiom Home Page Forums General Discussion Stereo back ported axiom speakers

Hi everybody!!: I only have experience with front ported speakers, e.g., JBL S-312. I'm interested on the Axiom's M-60 or M-80 speaker, but I see they are front and back ported. Do these speakers need to be very far from the walls?. I'm concerned as to how far I would have to place them from the wall, I only have about 20 inches (about 51cm) max from the wall to place them. I would have to toe them in with an angle of about 18 degrees. I would appreciate you input.

20 inches from the wall to the back of the speaker would be fine, (if thats what your reffering to) I currently have mine setup 31 inches from the wall to the back of the speaker at the nearest point but I dont have anyone else to complain about them being in the middle of the room.

20 inches from the back to the front of the speaker is quite a bit less than ideal.. to say the least.

You don't need to have them very far from the wall at all, usually; just a few inches. However, your room may vary. Why such an extreme toe in? I wouldn't start planning exact locations until you get the speakers. Be ready to play with placement; it can make a big difference.

I only have my M60s about 10 inches from the wall and though I'm sure I could pull them out and tighten up the bass a little more, they sound fantastic where they are. Besides, pull them out anymore and they're asking to get knocked over by the dogs when they get overexcited.

I think my 80s are about 6 inches from the wall, btw, with zero toe in at the moment.

I have my m80's about 8 inches from the wall and they sound great

Distance from the back wall is one thing. The very important other thing is distance from the side wall to avoid corner effects.

I guess i'm just part of some kind of audiophile freak show! I never did like putting them real close to the back wall

Thanks, I mean 20 inches from the back of the speakers, I did not visualized the toe in angle well, I would be about 10 degrees only. No problem with side walls plenty of space to place the speakers from the side wall. I'm just concerned on unnatural sounding reflexions of the wall, and not being able to place them further into the room.

When measuring the distance from the back wall the most important thing to remember is to measure the distance to the baffle where the middle of the speakers drivers are. Same when doing side measurements, measure to the middle of the speakers driver.

I guess 8" is enough room for some men...

8" here.

hey, not all of us have 20" to play with like rbr

20" must be a PITA

4' here, but I have a mancave so...

RB, welcome. As far as the rear ports go, the only requirement is to give them some "breathing room", and about 3" would be enough for that.

A more significant placement measurement would be to have the distances from the front wall, side wall and floor to the middle of the woofer cone unequal, if possible. The reason for this is so that the peaks and valleys caused by reflections from the room surfaces don't all pile up at the same frequencies.

What about the ceiling? The distance to the ceiling not equal to the floor, front and side walls is what you mean right? Also, I thought that you were supposed to make sure that those four distances aren't even divisible by one another. It seems like this would require a little bit of time since the m60's and m80's have 3 and 4 woofers respectively. My head hurts just thinking about it.

- Nick

Yeah, Nick; theoretically the ceiling should also be taken into account, but it usually isn't considered, since it would be very unusual to have a placement where the distance of the woofer cone to the ceiling was identical to the distance to the floor and both walls.

No, the evenly divisible lengths factor applies to the size of the room and the resulting modes. The reflections from the nearest room surfaces are a completely separate effect.

Why does Axiom M60 and M80 have 3 ports (two rear and one front)compared to other speakers which only have one or two in the rear? And why doesn't the VP150 doesn't have a port? Just curious...

jj

The M60 are bigger with more drivers. IIRC the tweeters, midranges, and woofers are segregated by internal bracing, which would seem to come into play.

As for the VP150, many people will place it inside a cabinet or stand of some sort, so it's designed for different constraints, eg. not being able to assume that there's room for a rear port to breathe.