port in the speakers

[sjith]

front ported speaker * rear ported speaker * speaker without ports

I have a pair of wharfedale speaker in my collection and no ports in it
(model wharfedale 425, its a bi-amping speaker with 100w @ 8 ohms, 88 db sensitivity)

from some threads rear ported speakers should keep at a distance away from the walls and no such restrictions for front ported speakers

how important is the speaker ports in operation and sound quality or reproduction

 

[aphile]

not a single reply from experts

 

[ketansethi1987]

@aphile In your case the speakers are sealed ones so you need not worry about maintaining any distance from the wall. Just keep them where you feel the sound is reproduced best for your ears.

There are different type of speakers boxes being manufactured like sealed (no ports), ported (one or more ports), Bandpass (sealed + ports), open baffle (open from back) etc.. depending on the advantages and disadvantages of both and also depending on the driver to be used in the box.

Ports are generally used to control the frequency response of the speakers.

A sealed box gives better power handling than a ported box. Similarly there are many more advantages and disadvantages of sealed box design.

In your speakers the manufacturer chose sealed box design to best suit the drivers and get the desired frequency response.

 

[adi_vastava]

I was also curious about one related topic.

Lets say the speaker has rear port; now if I mount it on wall; will there be an issue if the crossover is set to 100-120 (means there is a sub along with)?

Thanks
Aditya

 

[mandyrhtdm]

The basic principle here is that the characteristics of sound produced largely depend on the type of enclosure used, room acoustics and driver.

A Ported design is an invention which employs the Helmholtz Resonator Principle. What happens is when you have a port, the sound in the port acts like a mass and oscillates. the air inside the box acts like a spring which is tuned to resonate at a particular frequency. So say the driver can go only till 45 Hz on its own but you want the speakers to go till 30Hz. You will permute the Port size ( The mass) and the Cabinet Volume ( the Spring) to such a value that the resonance frequency of the port is 30Hz. so when the speaker produces 45Hz the Port can take it lower to 30 Hz.

The only loss here is on clarity.

In case you want to see this principle in action take a water bottle and fill it with waterr upto 80% of its height now blow air in the neck you will hear a sound. Now empty the water till 50% the now blow air in the neck. The sound will change that is the frequency response will change. This is the same principle employed in guitars etc.

 

[kapvin]

The basic principle here is that the characteristics of sound produced largely depend on the type of enclosure used, room acoustics and driver.

A Ported design is an invention which employs the Helmholtz Resonator Principle. What happens is when you have a port, the sound in the port acts like a mass and oscillates. the air inside the box acts like a spring which is tuned to resonate at a particular frequency. So say the driver can go only till 45 Hz on its own but you want the speakers to go till 30Hz. You will permute the Port size ( The mass) and the Cabinet Volume ( the Spring) to such a value that the resonance frequency of the port is 30Hz. so when the speaker produces 45Hz the Port can take it lower to 30 Hz.

The only loss here is on clarity.

In case you want to see this principle in action take a water bottle and fill it with waterr upto 80% of its height now blow air in the neck you will hear a sound. Now empty the water till 50% the now blow air in the neck. The sound will change that is the frequency response will change. This is the same principle employed in guitars etc.

I am curious. Could you explain what you mean by loss of clarity?

 

[mandyrhtdm]

The bass might not be as tight as a closed enclosure as the deep bass you hear is the result of the air resonance in the port. Which is tuned to a specific frequency that means the frequency response is not FLAT.

Plus they suffer from group effect. That is their is a delay between the cone movement and the port response to it so your bass might sound a bit muddy.

Third the air volume inside the speaker is not sealed as hence cannot offer a consistent stiffness ( it acts as a spring) to send the cone back to its normal position and hence the transient response suffer.

The plus side is that they can be very loud in comparison to sealed enclosure around the Tanisha. Frequency 50-30 HZ but the over all clarity suffers in principle
However a well designed ported enclosure will sound better than a poorly designed boXed enclosure. But as a fact sealed enclosures are more forgiving to design errors .

 

[sjith]

@aphile In your case the speakers are sealed ones so you need not worry about maintaining any distance from the wall. Just keep them where you feel the sound is reproduced best for your ears.

There are different type of speakers boxes being manufactured like sealed (no ports), ported (one or more ports), Bandpass (sealed + ports), open baffle (open from back) etc.. depending on the advantages and disadvantages of both and also depending on the driver to be used in the box.

Ports are generally used to control the frequency response of the speakers.

A sealed box gives better power handling than a ported box. Similarly there are many more advantages and disadvantages of sealed box design.

In your speakers the manufacturer chose sealed box design to best suit the drivers and get the desired frequency response.

any more details regarding "Bandpass (sealed + ports)"

 

[bhagwan]

Gentlemen - there is a lot that has been said in the above posts.
Not all of it is 100 % correct.
I am not keen to get into 'specifics'
A few feathers may get 'ruffled'
May I suggest that all read this link :-

http://en.wikipedia.org/wiki/Loudspeaker_enclosure

Please.
It may help you to get a good idea about loudspeaker enclosures - basics i.e.

Thank you.

 

[ranhounene]

Gentlemen - there is a lot that has been said in the above posts.

 

[ketansethi1987]

any more details regarding "Bandpass (sealed + ports)"

These are the most dificult to make.

Used for subwoofers - increase output, controls excursion and filters higher frequencies, can go really low

For example you must have seen today's 2.1 computer speakers...most of them have bandpass subwoofer specially if you have seen intex...there is only one opening from where all the sound come and air movement takes place...and no speaker/woofer is visible

It consist to two chambers one is sealed and one is having a port...ratio has to be maintained between the two for best sound...today's car subwoofers also have such enclosures...usualy the ones which have accralic over the top and woofer is visible through that..that is actauly the sealed chamber