Speaker and Wall distance

[Bill Gobby]

I'm looking for Bookshelves to replace my old Dynaco A25's.
The available space is right next to either side of a gas fireplace which extends out about 6 inches.
It looks like I'll need front ported speakers because of that.
My question is, why are speakers that are sealed or front ports still react to being near rear wall and corners.

Thanks in advance.

 

[j_garcia]

All speakers, regardless of design, will react to being near walls and corners.

 

[lsiberian]

Why can't you pull them out more? You can always pull them out for listening sessions and move them back for storage. 6" is normally too close for speaker to be to the wall.

 

[Bill Gobby]

All speakers, regardless of design, will react to being near walls and corners.

I was wondering Why it was a problem if there's No rear ports.
Ottguit

 

[Bill Gobby]

Why can't you pull them out more? You can always pull them out for listening sessions and move them back for storage. 6" is normally too close for speaker to be to the wall.

I think these paradigms studio 40's V3 weigh 40 lbs each and will be attached to stand, but I can probably forward them a few inches from the wall.
Ottguit

 

[Swerd]

I was wondering Why it was a problem if there's No rear ports.
Ottguit

It has nothing to do with speaker ports, and everything to do with frequency and the size of the room.

Read about the Schroeder frequency:

The short version from Wikipedia: http://en.wikipedia.org/wiki/Loudspeaker

Placement
In a typical rectangular listening room, the hard, parallel surfaces of the walls, floor and ceiling cause primary acoustic resonance nodes in each of the three dimensions: left-right, up-down and forward-backward.[40] Furthermore, there are more complex resonance modes involving three, four, five and even all six boundary surfaces combining to create standing waves. Low frequencies excite these modes the most, since long wavelengths are not much affected by furniture compositions or placement. The mode spacing is critical, especially in small and medium size rooms like recording studios, home theaters and broadcast studios. The proximity of the loudspeakers to room boundaries affects how strongly the resonances are excited as well as affecting the relative strength at each frequency. The location of the listener is critical, too, as a position near a boundary can have a great effect on the perceived balance of frequencies. This is because standing wave patterns are most easily heard in these locations and at lower frequencies, below the Schroeder frequency – typically around 200–300 Hz, depending on room size.

Or the more complex version with all the acoustics explained with math

 

[j_garcia]

I was wondering Why it was a problem if there's No rear ports.
Ottguit

Front ported or sealed will be affected less, but they are still affected when placed too close. Speakers technically radiate spherically from the speaker, not directly out like most diagrams show, so the sound can still be influenced when placed very close. Some speakers behave better than others when in this situation as well. Last year I tried some rear ported speakers basically less than 2" from my wall because I had no choice, and to my surprise, they were fine, where pretty much every other speaker I've done that with the bass bloat became obvious.

 

[Bill Gobby]

Read about the Schroeder frequency:


Placement
In a typical rectangular listening room, the hard, parallel surfaces of the walls, floor and ceiling cause primary acoustic resonance nodes in each of the three dimensions: left-right, up-down and forward-backward.[40] Furthermore, there are more complex resonance modes involving three, four, five and even all six boundary surfaces combining to create standing waves. Low frequencies excite these modes the most, since long wavelengths are not much affected by furniture compositions or placement. The mode spacing is critical, especially in small and medium size rooms like recording studios, home theaters and broadcast studios. The proximity of the loudspeakers to room boundaries affects how strongly the resonances are excited as well as affecting the relative strength at each frequency. The location of the listener is critical, too, as a position near a boundary can have a great effect on the perceived balance of frequencies. This is because standing wave patterns are most easily heard in these locations and at lower frequencies, below the Schroeder frequency – typically around 200–300 Hz, depending on room size.

Excellent Reply,
The first sentence kinda says it all,, and rest explains it
thanks muchly.

It has nothing to do with speaker ports, and everything to do with frequency and the size of the room.

Read about the Schroeder frequency:

The short version from Wikipedia: http://en.wikipedia.org/wiki/Loudspeaker

Placement
In a typical rectangular listening room, the hard, parallel surfaces of the walls, floor and ceiling cause primary acoustic resonance nodes in each of the three dimensions: left-right, up-down and forward-backward.[40] Furthermore, there are more complex resonance modes involving three, four, five and even all six boundary surfaces combining to create standing waves. Low frequencies excite these modes the most, since long wavelengths are not much affected by furniture compositions or placement. The mode spacing is critical, especially in small and medium size rooms like recording studios, home theaters and broadcast studios. The proximity of the loudspeakers to room boundaries affects how strongly the resonances are excited as well as affecting the relative strength at each frequency. The location of the listener is critical, too, as a position near a boundary can have a great effect on the perceived balance of frequencies. This is because standing wave patterns are most easily heard in these locations and at lower frequencies, below the Schroeder frequency – typically around 200–300 Hz, depending on room size.

Or the more complex version with all the acoustics explained with math

 

[Bill Gobby]

Read about the Schroeder frequency:


Placement
In a typical rectangular listening room, the hard, parallel surfaces of the walls, floor and ceiling cause primary acoustic resonance nodes in each of the three dimensions: left-right, up-down and forward-backward.[40] Furthermore, there are more complex resonance modes involving three, four, five and even all six boundary surfaces combining to create standing waves. Low frequencies excite these modes the most, since long wavelengths are not much affected by furniture compositions or placement. The mode spacing is critical, especially in small and medium size rooms like recording studios, home theaters and broadcast studios. The proximity of the loudspeakers to room boundaries affects how strongly the resonances are excited as well as affecting the relative strength at each frequency. The location of the listener is critical, too, as a position near a boundary can have a great effect on the perceived balance of frequencies. This is because standing wave patterns are most easily heard in these locations and at lower frequencies, below the Schroeder frequency – typically around 200–300 Hz, depending on room size.

Excellent Reply,
The first sentence kinda says it all,, and rest explains it
thanks muchly.

 

[Bill Gobby]

Front ported or sealed will be affected less, but they are still affected when placed too close. Speakers technically radiate spherically from the speaker, not directly out like most diagrams show, so the sound can still be influenced when placed very close. Some speakers behave better than others when in this situation as well. Last year I tried some rear ported speakers basically less than 2" from my wall because I had no choice, and to my surprise, they were fine, where pretty much every other speaker I've done that with the bass bloat became obvious.

Thanks for that info as well Mr.G
Ottguit