Front-ported vs rear ported monitors close to a wall? Is there really a difference?

[Decaf]

Hello,

I’ve been scouring the internet for answers to this question and finding mixed answers. I’m aware that lots of people tend to regurgitate what they read online, rather than speak from true experience or education.

I’m finding one camp of people saying rear-ported monitors should not be placed close to the back wall, and front-ported monitors would be better. I’m finding other people saying that rear ported monitors are fine (or better even) when placed relatively close to the wall (a few inches, depending on port diameter).

So for all the others out there trying to research this, I’d like to keep this as a general discussion, rather than going into the specifics of my space/speakers/budget (I may make a separate post for this). Please can anyone speak from experience comparing front vs rear ported monitors close to a wall, or anyone with a good knowledge of acoustics, as I feel there is too much information-regurgitation elsewhere on the internet.

 

[Purité Audio]

Personally not really a fan of ported designs , but bass below 80Hz is omnidirectional and cant be localised, so I would
imagine no difference.
Keith

 

[LTig]

AFAIR Genelec recommends a Minimum distance of 5 cm (2 inch) between Port opening and wall. If you keep this distance a back firing port should be no issue.

If the speaker has port resonances at higher frequencies those may be less audible with rear firing ports. Not a problem with Genelec or Neumann, of course.

 

[sigbergaudio]

Hello,

I’ve been scouring the internet for answers to this question and finding mixed answers. I’m aware that lots of people tend to regurgitate what they read online, rather than speak from true experience or education.

I’m finding one camp of people saying rear-ported monitors should not be placed close to the back wall, and front-ported monitors would be better. I’m finding other people saying that rear ported monitors are fine (or better even) when placed relatively close to the wall (a few inches, depending on port diameter).

So for all the others out there trying to research this, I’d like to keep this as a general discussion, rather than going into the specifics of my space/speakers/budget (I may make a separate post for this). Please can anyone speak from experience comparing front vs rear ported monitors close to a wall, or anyone with a good knowledge of acoustics, as I feel there is too much information-regurgitation elsewhere on the internet.

In practice there will be little difference. Both a front ported, rear ported and sealed design will get bottom end gain when placed close to the wall.

Whether this position gives you a balanced sound or too much bass, depends on the tuning of that specific speaker (what it was designed for), rather than where the port is located. It's fully possible to design a rear ported speaker to work well close to the wall. That doesn't mean that ALL rear ported speakers work well close to the wall. This might be the reason you see many different answers on this topic, since people's experience may differ based on which speaker they've tried.

 

[Basic Channel]

You get wildly different opinions because of how different speakers are in terms of frequency response. Putting the speaker against the wall will bump up the bass, whether that's good or not depends on the speaker. It's not really feasible in a lot of rooms to have the speakers spaced out from the backwall, so the best alternative is to have them close against the wall. Yamaha recommends that the HS5s are placed 1.5 from any corner or wall but I cannot do that because I live in a bog standard European house.

If I try to follow Yamaha's advice and go for 1m distance, I'll create a big dip at 80hz or so (based on memory). The closer I go to the wall, the higher the null gets. Ideally a speaker should be placed 0.000001mm or 20m from the backwall. Probably the latter, but I work in a bank I don't own one!!

 

[mixsit]

In practice there will be little difference. Both a front ported, rear ported and sealed design will get bottom end gain when placed close to the wall.

Whether this position gives you a balanced sound or too much bass, depends on the tuning of that specific speaker (what it was designed for), rather than where the port is located. It's fully possible to design a rear ported speaker to work well close to the wall. That doesn't mean that ALL rear ported speakers work well close to the wall. This might be the reason you see many different answers on this topic, since people's experience may differ based on which speaker they've tried.

I got into this with my SPTech Continuum AD's which are rear ported. Up shot was 'enough not to restrict their free circulation -several inches or less.
https://www.audiosciencereview.com/...2-way-or-three-way-speaker.55272/post-2010783

 

[ozzy9832001]

Hello,

I’ve been scouring the internet for answers to this question and finding mixed answers. I’m aware that lots of people tend to regurgitate what they read online, rather than speak from true experience or education.

I’m finding one camp of people saying rear-ported monitors should not be placed close to the back wall, and front-ported monitors would be better. I’m finding other people saying that rear ported monitors are fine (or better even) when placed relatively close to the wall (a few inches, depending on port diameter).

So for all the others out there trying to research this, I’d like to keep this as a general discussion, rather than going into the specifics of my space/speakers/budget (I may make a separate post for this). Please can anyone speak from experience comparing front vs rear ported monitors close to a wall, or anyone with a good knowledge of acoustics, as I feel there is too much information-regurgitation elsewhere on the internet.

Depends on how the port is designed and what frequency it's tuned too.

I've never had good luck with front ported speakers, except my Edifiers. They tend to chuff and moderate volumes. Rear ported you won't hear as much, but they do need space to breath.

General rule of thumb for rear ports is the diameter of the port distance to the wall. For most that's 2-4 inches. If the port itself is causing issues or the boost is undesirable, then it can be plugged. A wadded up sock makes a good impromptu plug.

 

[valerianf]

Preference depend of the speaker design.
For a bookshelf speaker a BR port placed at the back is ok.
For a large column speaker a front BR port is mandatory: the stronger low frequency enhancement from the port should be directed toward the couch.
Interestingly I have a center speaker with 2 lateral BR ports and the result is fully satisfying.

Until now none of the BR port design that I used makes any trouble.
But several time I had to change the bass driver because it's parameters were not optimal during BR simulation.
Improvement needs to be simulated and tested in real life.

 

[holdingpants01]

In reality it doesn't matter, here's the in room response comparison of Genelec 8040 (back port) and Neumann KH150 (front port). The room completely dominates over any differences between the two below 200Hz. Both were in the same spot and very close to back wall

 

[Pareto Pragmatic]

As a general rule, "avoid rear ports close to walls" will lead to better results for most people in most situations.

I generally pick my speaker first, then worry about ports later for MOST situations. Given 24" from the wall, I would not personally care, 12" I might care a bit, but I am using rear ported speakers at 12" in my office currently. Closer and definitely if I was wall mounting, I would try to find front port options.

Speakers usually have specs that include how close to the wall to place them. It's a good idea to use that as a starting point. If the manufacturer says 2" or 12", there is likely a reason.

One big difference is how the port engages the rear wall. Toe a rear ported speaker in, you bounce the port sound to the outside of the room. Front port or sealed does not have that effect added on top of the normal effect of being close to a wall. This means you should be careful about the direct and reflected path from the port. A window frame, objects on a desk, etc. might be in the way and affect that part of the sound. Port sound is very narrow close to the speaker, so even small objects/irregularities can bounce a lot of that sound in undesired directions.

 

[Purité Audio]

It appears to me this port thing is another audio myth, I often read of ports setting off rooms and how they should be avoided but if we look at @holdingpants01 plots above…
Personally I prefer sealed enclosures.
Keith

 

[Elkerton]

In any case, if there is too much bass when the ported speaker is placed close to the wall, the port can be plugged so that the speaker's bass response starts to roll off at a higher frequency more slowly, usually in the 100 to 200 Hz range, just below middle C.

 

[Decaf]

Thank you all for your replies! Super helpful for me and I hope helpful for many others wondering and googling the same thing. As a result, I’m gonna get me a pair of genelecs

 

[akamatsu]

I have some rear ported stand mount speakers. The manufacturer recommends close to the wall. They sound best 3 to 4 inches away. I recently set up a pair of front ported stand mounts and the same manufacturer recommends a minimum of 9 inches from the wall. So it depends on the speaker and what they were designed for.