[Czilla9000]

Hi gang,

Anyone know if you can use "normal" speakers in near-field placement? Or will only computer speakers or studio monitors do?

Presumably things might be too trebly, but wouldn't Audessey or MCACC compensate for that? Or is their a "minimum distance" those need to work?

 

[jaddie]

Hi gang,

Anyone know if you can use "normal" speakers in near-field placement? Or will only computer speakers or studio monitors do?

Presumably things might be too trebly, but wouldn't Audessey or MCACC compensate for that? Or is their a "minimum distance" those need to work?

One of the problems with large speakers near field is the physical distance between different drivers. In the crossover region, near field, things get a bit strange and unpredictable. Purpose-made near-field monitors have either coaxial drivers or closely spaced ones with crossovers optimized for near field.

Just placing them near won't make them much brighter, and yes Audyssey would straighten out some of that. The problem you may get into is a relatively small sweet spot.

 

[FMW]

Perhaps it would help to better understand the meaning of "near field." The term comes from pro audio and it distinguishes listening from distances in normal sized rooms such as recording studios. Far field is listening in performance venues. In the pro audio business, near field monitors are like home audio monitors. Public address monitors are designed to deliver high SPL's while being driven by high power in places such as auditoriums.


The term has been hijacked by the home audio industry to mean listening very close such as with computer audio on a desk. The point is that the speakers are the same. They are all basically non-PA speakers.


For very close listening I recommend bookshelf speakers supported by a subwoofer. It doesn't matter whether they are distributed by the pro audio channel or the home audio channel.

 

[Bill Fitzmaurice]

The term has been hijacked by the home audio industry to mean listening very close such as with computer audio on a desk. The point is that the speakers are the same. They are all basically non-PA speakers.

Not exactly.
In audio there are three definitions of near field and far field. One is the zone in which a speaker works as a line source versus point source. Where the radiation characteristic is line source is the near field, where it is point source is the far field. It explains how line arrays work differently than point sources. Jim Griffin's whitepaper on line arrays explains it well.
The second is referenced to mic placement when measuring speaker response, usually meaning an inch or so from the driver or port output being measured. Doing so each radiating element of the speaker is measured individually, with their responses summed to give the full broadband result. This differs from a far field measurement, where the mic is placed beyond the point in space where all of the wave fronts have integrated into one.
Where speakers are concerned near fields are defined as being designed for listening at close distances, configured so that even at, say, four feet, the individual wave fronts are fully integrated into one. That makes the use of the name 'near field' a misnomer, as what it actually means is that the speaker is functioning in the far field quite close to the speaker.
The use of the name 'near field monitor' isn't related to the home audio industry. It was coined by the recording industry, where near fields are typically mounted on or just above the console, quite close to the listening position of the engineer. They got the name 'near field' from the fact that the listener is near them.

 

[Bill Fitzmaurice]

The term has been hijacked by the home audio industry to mean listening very close such as with computer audio on a desk. The point is that the speakers are the same. They are all basically non-PA speakers.

Not exactly.
In audio there are three definitions of near field and far field. One is the zone in which a speaker works as a line source versus point source. Where the radiation characteristic is line source is the near field, where it is point source is the far field. It explains how line arrays work differently than point sources. Jim Griffin's whitepaper on line arrays explains it well.
The second is referenced to mic placement when measuring speaker response, usually meaning an inch or so from the driver or port output being measured. Doing so each radiating element of the speaker is measured individually, with their responses summed to give the full broadband result. This differs from a far field measurement, where the mic is placed beyond the point in space where all of the wave fronts have integrated into one.
Where speakers are concerned near fields are designed for listening at close distances, configured so that even at, say, four feet, the individual wave fronts are fully integrated into one. That makes the use of the name 'near field' a misnomer, as what it actually means is that the speaker is functioning in the far field quite close to the speaker.
The use of the name 'near field monitor' isn't related to the home audio industry. It was coined by the recording industry, where near fields are typically mounted on or just above the console, quite close to the listening position of the engineer. They got the name 'near field' from the fact that they're placed near the listener.

 

[Czilla9000]

Not exactly.
In audio there are three definitions of near field and far field. One is the zone in which a speaker works as a line source versus point source. Where the radiation characteristic is line source is the near field, where it is point source is the far field. It explains how line arrays work differently than point sources. Jim Griffin's whitepaper on line arrays explains it well.
The second is referenced to mic placement when measuring speaker response, usually meaning an inch or so from the driver or port output being measured. Doing so each radiating element of the speaker is measured individually, with their responses summed to give the full broadband result. This differs from a far field measurement, where the mic is placed beyond the point in space where all of the wave fronts have integrated into one.
Where speakers are concerned near fields are designed for listening at close distances, configured so that even at, say, four feet, the individual wave fronts are fully integrated into one. That makes the use of the name 'near field' a misnomer, as what it actually means is that the speaker is functioning in the far field quite close to the speaker.
The use of the name 'near field monitor' isn't related to the home audio industry. It was coined by the recording industry, where near fields are typically mounted on or just above the console, quite close to the listening position of the engineer. They got the name 'near field' from the fact that they're placed near the listener.

So, if I understand you right, I can't use speakers designed for "normal" distances in near-field (i.e, two feet away or so) because the wavefronts won't converge right?

 

[Bill Fitzmaurice]

So, if I understand you right, I can't use speakers designed for "normal" distances in near-field (i.e, two feet away or so) because the wavefronts won't converge right?

Right. It's not that you can't use them, but the imaging sweet spot will be so small that moving your head in any direction even a few inches will cause the imaging to collapse.

 

[Czilla9000]

Right. It's not that you can't use them, but the imaging sweet spot will be so small that moving your head in any direction even a few inches will cause the imaging to collapse.

Okay, but if a speaker was "1-way" (i.e., used a full range driver with no crossover) it wouldn't matter if you used them nearfield or farfield?

 

[Bill Fitzmaurice]

Okay, but if a speaker was "1-way" (i.e., used a full range driver with no crossover) it wouldn't matter if you used them nearfield or farfield?

No, because there are no multiple wave fronts to integrate.

 

[FMW]

Not exactly.
In audio there are three definitions of near field and far field. One is the zone in which a speaker works as a line source versus point source. Where the radiation characteristic is line source is the near field, where it is point source is the far field. It explains how line arrays work differently than point sources. Jim Griffin's whitepaper on line arrays explains it well.
The second is referenced to mic placement when measuring speaker response, usually meaning an inch or so from the driver or port output being measured. Doing so each radiating element of the speaker is measured individually, with their responses summed to give the full broadband result. This differs from a far field measurement, where the mic is placed beyond the point in space where all of the wave fronts have integrated into one.
Where speakers are concerned near fields are designed for listening at close distances, configured so that even at, say, four feet, the individual wave fronts are fully integrated into one. That makes the use of the name 'near field' a misnomer, as what it actually means is that the speaker is functioning in the far field quite close to the speaker.
The use of the name 'near field monitor' isn't related to the home audio industry. It was coined by the recording industry, where near fields are typically mounted on or just above the console, quite close to the listening position of the engineer. They got the name 'near field' from the fact that they're placed near the listener.

Thanks, Bill. I understand it better now.

 

[Bill Fitzmaurice]

Thanks, Bill. I understand it better now.

It doesn't help when the same term defines three very different things.

 

[Czilla9000]

No, because there are no multiple wave fronts to integrate.

Okay, let me ask a follow up - I've always heard, though, that 1-way speakers are more difficult to place correctly as larger drivers beam the treble more directionally, making there be a smaller sweet spot. Is that true?

So, one-way designs should have a larger sweet spot because there are no multiple wave fronts to integrate, but conversely they should have a smaller sweet spot because they beam the treble? I guess one cancels out the other?

 

[Bill Fitzmaurice]

Okay, let me ask a follow up - I've always heard, though, that 1-way speakers are more difficult to place correctly as larger drivers beam the treble more directionally, making there be a smaller sweet spot. Is that true?

Yes. That's why full range drivers tend to be small, five inches or less.

 

[jaddie]

Yes. That's why full range drivers tend to be small, five inches or less.

...which makes "full range" a very relative term. In practice, there's really no such thing, if you consider the need to monitor audio on a system that's basically flat through the entire audio spectrum. And probably why somebody using a "full range" speaker once said, "You know, if we get a big one for the bass, and a small one for the treble, that might work better!"

At least that's what they said in my own revisionist history book.

 

[Bill Fitzmaurice]

...which makes "full range" a very relative term. In practice, there's really no such thing

Of course not. No driver is large enough to have adequate displacement to handle lows with authority and small enough to have good dispersion in the highs. You can do one or the other, but not both. Single driver system aficionados claim that the advantages of using a single driver outweigh the disadvantages, but it just isn't so. There's a reason why an orchestra has physically large instruments, like tubas and double basses, to handle the lows and small instruments, like piccolos and violins, to handle the highs. That same reason applies to why speaker systems need at least three drivers of varying size to cover the entire audio bandwidth.

 

[PrimeTime]

That same reason applies to why speaker systems need at least three drivers of varying size to cover the entire audio bandwidth.

I would assume that by "three drivers" you're including the modern-day subwoofer as the third driver.

There is a rather well-engineered (two years) line source in another DIY forum that uses thirty or so excellent small drivers. His measurements, at least, show a pretty good attempt at a one-driver system.

And then there's the Bose 901, which demonstrated just how effective active equalization can be.

Then again, expectations for low-frequency extension have expanded over the years.

 

[jaddie]

And then there's the Bose 901, which demonstrated just how effective active equalization can be.

Then again, expectations for low-frequency extension have expanded over the years.

The 901 was a total cheat. Even with the EQ doing 50+dB of boost at 20Hz it still couldn't produce any significant SPL at 30Hz, and what it could do was thoroughly laden with THD. Almost any sealed box could beat it with no EQ. As in most Bose products, high marks for innovation, low marks for performance in the real world. Oh, and superlative marketing.

 

[|Tch0rT|]

There is a rather well-engineered (two years) line source in another DIY forum that uses thirty or so excellent small drivers. His measurements, at least, show a pretty good attempt at a one-driver system.

I'm pretty sure he's referring to single driver crossoverless horn loaded full range style speakers like something that looks like this:

Line arrays are different.

 

[IKM]

The 901 was a total cheat. Even with the EQ doing 50+dB of boost at 20Hz it still couldn't produce any significant SPL at 30Hz, and what it could do was thoroughly laden with THD. Almost any sealed box could beat it with no EQ. As in most Bose products, high marks for innovation, low marks for performance in the real world. Oh, and superlative marketing.

Wait, what's wrong with Bose now?

 

[Bill Fitzmaurice]

And then there's the Bose 901, which demonstrated just how effective active equalization can be.

EQ can't fix dispersion, and dispersion is the reason why multiple driver sizes are used.