Rear ports...

[Tonestar1]

Why do the vast majority of manufacuters put rear ports on their speakers when the vast majority of punters want to place their speakers close to a wall? I'm talking budget to mid end here. Seems crazy to me the manufacurers don't design their speakers to be positioned in the real world. Surely front porting or optimsing speakers to be close to a wall should be the given as thats where most will situate them. 50cm from a wall and a corner is not a practical position in most folks listening areas. What is the reason for this?

 

[jjbomber]

What is the reason for this?

Speakers look better with the ports hidden around the back and a nice looking sealed front. Most people buy on look.

 

[Andrewjvt]

Not so long ago about this.
I think someone pointed out that it's a hifi myth that rear ported effects the bass worse than forward ported close to walls (does not make sense I know)

Hope the person will clarify

But if you want free of bass port altogether get a sealed speaker.

 

[plastic penguin]

Most modern budget/midrange standmount are quite dinky. No room for a front port with the drivers.... so it only seems logical to place the port either at the rear, side or underneath the cabinet.

 

[davedotco]

Not so long ago about this. I think someone pointed out that it's a hifi myth that rear ported effects the bass worse than forward ported close to walls (does not make sense I know)

Hope the person will clarify

But if you want free of bass port altogether get a sealed speaker.

The position of the port on any properly designed speaker is irrelevant so long as it is not so close to a boundary as to restrict airflow.

Boundary reinforcement of bass is well known and a few manufactures do design for near wall placement, classic Linn and Naim speakers were designed this way, as are some modern designs from Neat, Guru and of course Chebby's Audionotes.

Most speakers are designed to work best with a bit of space, this, generally speaking, gives a better soundstage and a more open, spacious sound, designers like this as the speakers 'review' better.

Making the bass adjustable for different positions is not easy to implement in passive designs but is commonplace in most small active studio monitors (even the AE1a have this) where it is carried out by the active crossover, often with the aid of dsp.

This is another reason why such speakers work so well in the home, my Adams are normally used within about 6 inches of the backwall, for practical, domestic reasons. The bass shelving allows me to adjust the bass to suit and though these are relatively simple models without dsp, the adjustment works fine.

Even speakers like the budget Presonus Eris 5 (less than £250pr) have comprehensive adjustments to allow for different positions and other controls to then balance the speaker to your requirements, more sophisticated designs such as the Dynaudio Lyd make these adjustments using dsp ans still cost less than £1k all but the biggest models.

 

[chebby]

Not so long ago about this. I think someone pointed out that it's a hifi myth that rear ported effects the bass worse than forward ported close to walls (does not make sense I know)

It only makes sense if you consider the port as a driver (it’s not) rather than as somethng that ‘tunes’ the bass response of the cabinet. It needs a little room to do it’s job (just a few inches in some cases).

For the technicalities I refer you to messrs Briggs and Villchur and all decent loudspeaker designers since

My rear-ported speakers (AN AX-Twos) were designed for optimal performance close to walls and corners and my experience agrees.

 

[Muddywaterstones]

Why do the vast majority of manufacuters put rear ports on their speakers when the vast majority of punters want to place their speakers close to a wall? I'm talking budget to mid end here. Seems crazy to me the manufacurers don't design their speakers to be positioned in the real world. Surely front porting or optimsing speakers to be close to a wall should be the given as thats where most will situate them. 50cm from a wall and a corner is not a practical position in most folks listening areas. What is the reason for this?

Isn't part of the problem the very nature of how bass works? It doesn't come out of the driver in straight lines but is omni-directional, akin to dropping a pebble in a pond and rippling out from the centre. Thus, if you can spare some room around the speakers it aids performance, delaying the reflections off the walls, or at least giving you the chance to tune it a bit.

 

[macdiddy]

thats what I did to a pair of Mission rear ported floorstanders that I wanted to use up against a wall (due to lack of floor space).

cheaper than buying a pair of actives.

*dance4*

 

[davedotco]

because of size and i guees ane long small port makes a difference to a big round hole

Are all about the 'mass' of the air in the port and this is what defines the resonant frequency which is used to lift the bass. The shape and dimensions of the port can be varied to adjust the 'Q', ie how narrow or how wide the resonance is and therefore how narrow and or how wide the bass lift is. This is putting this pretty crudely but gives an idea of how this works.

Blocking the port with a sock for example will change these parameters and reduce the bass response, it will also make the speaker sound more 'shut in' and less airy. That is my experience anyway.

 

[Gray]

If it's ported, then for me it's front ported.

Yes, I'm close(ish) to rear wall, but not enough to influence rear port airflow.

In answer to the OP question, as others have pointed out, they're often on the back due to lack of front space or just to keep them out of sight.

Regarded by some as irrelevant, I've found port position to be make or break.

 

[davedotco]

If it's ported, then for me it's front ported.

Yes, I'm close(ish) to rear wall, but not enough to influence rear port airflow.

In answer to the OP question, as others have pointed out, they're often on the back due to lack of front space or just to keep them out of sight.

Regarded by some as irrelevant, I've found port position to be make or break.

Can sometimes suffer from reflexions from inside the cabinet being audible at the listening position, particularly so in the case of designs where the cabinet is lightly damped with internal material. Otherwise it should really make no difference where the port is.

Be interesting to know what experiences have formed your views on this.

 

[plastic penguin]

The best I've heard for rear ported that goes close to the wall were the Ruark Sabre IIIs. But these aren't made anymore, Linn and Naim speakers aren't always stocked by Naim or Linn dealers, Chebby's Audionotes have to be ordered online (very limited outlets).

I would suggest the vast amount of readily available rear ported speakers aren't great when close to a wall - I know this from personal expereince. This makes the whole logic of small standmounts a nonsense: They are by definition designed to work in small rooms. But if you have a small room the chances of having these speakers 12-18" from a wall will be practically impossible. Why is that? Well, because although the height and width of modern standmounts have become smaller and smaller, these speakers have become a lot deeper.

IMO, companies like Kef, Monitor Audio, Dynaudio blah blah... need to rethink speaker design. As newer houses get smaller the speakers get deeper: Solution? No idea, other than compact floorstanders. They aren't the answer nor are they the problem.

 

[davedotco]

Modern speaker design is really not very room friendly, they usually err towards too much bass rather than to little because that is what 'most' buyers prefer. Placed optimally (in space) by a reviewer or dealer they will sound more open, have more depth and a better soundstage but for a lot of people this is not replicated in the home.

Old style Linn and Naim speakers, i'm thinking Kans, Saras, Ibl and SBL among others were all designed to go tight to a wall, this had the disadvantage of destroying any depth in the soundstage and could sound very two dimensional and sometimes rather boxed in.

On the other hand the sound would usually translate very well from the showroon to the customers home, a degree of consistenty that dealers in particularly found very helpful.

 

[QuestForThe13thNote]

That’s why a good transmission line speaker works well. Project that bass around the room forward and not rearward. With a port in the front. You know who I mean.....

 

[davidf]

Why do the vast majority of manufacuters put rear ports on their speakers when the vast majority of punters want to place their speakers close to a wall?

Have you ever put you ear near to a port to hear what comes out of it?

 

[gasolin]

because of size and i guees a long small port makes a difference to a big round hole

 

[Gray]

Modern speaker design is really not very room friendly, they usually err towards too much bass rather than to little because that is what 'most' buyers prefer. Placed optimally (in space) by a reviewer or dealer they will sound more open, have more depth and a better soundstage but for a lot of people this is not replicated in the home.

Indeed Dave, not for me.

I bought a pair of Proac Tablette Reference 8 speakers after a very favourable (and very much free space) dealer demonstration. In the demo, their imaging was the best I'd heard.

At home things weren't so good. Still obviously a great little speaker in many respects but the performance was obviously compromised. A small band of frequencies, maybe 200-250Hz, was being artificially emphasised to the point of unacceptability.

These were my first rear ported design. I'm aware that room boundaries effect the sound of any speaker, ported or not, but I'm certain that I would have kept those Proacs had they been front ported.

No coincidence I think, that I've had no such issue with any subsequent, front ported, speaker at round 6 - 10" from the rear wall.

 

[Al ears]

Most modern budget/midrange standmount are quite dinky. No room for a front port with the drivers.... so it only seems logical to place the port either at the rear, side or underneath the cabinet.

+1. It's the diamentional limitations

 

[Al ears]

Most modern budget/midrange standmount are quite dinky. No room for a front port with the drivers.... so it only seems logical to place the port either at the rear, side or underneath the cabinet.

+1. It's the diamentional limitations.

No point putting it underneath as most people use them on stands.

 

[hybridauth_Facebook_100004211376004]

Wilson and benesch Arc spring to mind for the port facing the floor.....oh I'd love to hear a pair of them even though they're getting on a bit now