Understanding sound reproduction - and how it is evaluated

[chebby]

I have read the article.

Please excuse me if I have missed the answer to the following questions...

What should I, as a normal customer (a technical layman with no lab equipment), actually do when I come to buy my next pair of loudspeakers? What can I - in practical terms - take from the article and use to make my purchase a better one?

Thanks.

 

[hoopsontoast]

Not sure how strong our language can be on this forum but the author of this piece is a blitthering eddiaat!

who listens to 'speakers' as a stand alone device - of course box design, crossovers, ports etc have an enormus effect on what we hear - the same driver in two different box designs can and will sound very different to each other and when compared to the same driver used unboxed on a table.

note - its 'figures' will still read the same through 'measurement tools' if the source is fixed, I mean derr!

your first thought is quite right but the second one not so much. just for instance, baffle size and enclosure shape will change speaker's frequency response quite considerably, depending on shape, so a speaker designer has to take this into account when designing a speaker. this fact will most likely be compensated by crossover network.

so there you have it; figures will not read the same.

Sorry, but are you telling me an electrical signal going through an electrical unit its properties will change?

what you speak of is colleration of the sound produced due to surrounding materials, the actual readings should not change if the signal being fed to said device is fixed.

eg - PMC use transmission line technology to enhance bass using materials and ..er technology and such (WHF's review of the 22's explians it in the blue box at the bottom of the review, better than me) ,but remove the transmission line and the enhanced bass is removed. The speaker output does not change, nor its frequency response if the signal is unchanged - what we hear is though.

which is why speakers CAN be discribed as transparent, warm, clinical etc, we buy the design, not individual drivers, but the tech that makes them work as a whole a single unit reproducing our music.

The authors desire to remove this simple fact and break it down to individual drivers and measurments is really pretty silly

I think you need to learn some speaker design theory. :type:

For example, take the drivers out of the PMC 22 TL cabinet and put them in a wide baffle sealed box and it will sound completley different. The Raw driver will be outputing the same signal, but the frequency response will be vastly different as it is affected by baffle width, height, stuffing in the cabinet, reflections of internal braces and walls etc etc.

Transmission line (Tuned Pipe actually as PMC use it) not only affects the low bass, but also dampening in the mid range.

 

[oldric_naubhoff]

Not sure how strong our language can be on this forum but the author of this piece is a blitthering eddiaat!

who listens to 'speakers' as a stand alone device - of course box design, crossovers, ports etc have an enormus effect on what we hear - the same driver in two different box designs can and will sound very different to each other and when compared to the same driver used unboxed on a table.

note - its 'figures' will still read the same through 'measurement tools' if the source is fixed, I mean derr!

your first thought is quite right but the second one not so much. just for instance, baffle size and enclosure shape will change speaker's frequency response quite considerably, depending on shape, so a speaker designer has to take this into account when designing a speaker. this fact will most likely be compensated by crossover network.

so there you have it; figures will not read the same.

Sorry, but are you telling me an electrical signal going through an electrical unit its properties will change?

what you speak of is colleration of the sound produced due to surrounding materials, the actual readings should not change if the signal being fed to said device is fixed.

eg - PMC use transmission line technology to enhance bass using materials and ..er technology and such (WHF's review of the 22's explians it in the blue box at the bottom of the review, better than me) ,but remove the transmission line and the enhanced bass is removed. The speaker output does not change, nor its frequency response if the signal is unchanged - what we hear is though.

which is why speakers CAN be discribed as transparent, warm, clinical etc, we buy the design, not individual drivers, but the tech that makes them work as a whole a single unit reproducing our music.

The authors desire to remove this simple fact and break it down to individual drivers and measurments is really pretty silly

I think you need to learn some speaker design theory. :type:

For example, take the drivers out of the PMC 22 TL cabinet and put them in a wide baffle sealed box and it will sound completley different. The Raw driver will be outputing the same signal, but the frequency response will be vastly different as it is affected by baffle width, height, stuffing in the cabinet, reflections of internal braces and walls etc etc.

Transmission line (Tuned Pipe actually as PMC use it) not only affects the low bass, but also dampening in the mid range.

you beat me to it hoopsontoast

Thompsonuxb, why don't you google Olson baffle shape for pictures and baffle step compensation for some theory. what it basically means is that if you apply the same driver in different enclosures it will produce a different freq response. raw driver's freq response would most likely be measured on infinite baffle. do you have your speakers mounted on infinite baffle? I doubt it (the closest approximation would be drivers flush in wall or ceiling). and if flat freq response is anything to strive for then you have to compensate for baffle during speaker design.

however, that article is not about baffles. it's more about knowing how individual drivers measure so you can tell how music would sound reproduced by them.

 

[nopiano]

I have read the article.

Please excuse me if I have missed the answer to the following questions...

What should I, as a normal customer (a technical layman with no lab equipment), actually do when I come to buy my next pair of loudspeakers? What can I - in practical terms - take from the article and use to make my purchase a better one?

Thanks.

If I could find the 'hitting nail on head' icon, chebby, I would gladly award it to you.

I'm not averse to a bit of isolated technical argument and measurement. Seems not so long ago I thought that square-wave measurement, almost never seen today, was the holy grail. Just so happened that my then fave brand Harman/Kardon used these to show their low-end superiority over receiver rivals (in the 70's for those too young to have guessed). See if you can find a pickup cartridge tracking a square-wave and you'll wonder how anyone can listen to vinyl!

What always drags me back to listening is that I use the same ears in a concert hall, recital room, rock arena (etc) as I do at home. That handily takes account of the too-many-to-count interfaces and influences, such as mics, placement, mixing, AD/DA conversion, medium, amps, speakers, cables, mains etc..., not to mention my mood and tiredness, and which type of box the speaker-drivers are fastened to.

I'm definitely drawn to good-measuring kit that sounds great, rather than weirdly measuring kit that might sometimes be amazing. But that's a sort of confidence thing. A bit like a great performer can appear to sail above the demands of their performance, and the music just flows through them and you cannot imagine it done better. That's what good hi-fi can do, even if it might never be mistaken for the live event. You might just suspend disbelief for a while, though.

 

[Thompsonuxb]

No, oldric_naubhoff and hoopsontoast you guys are wrong.

eh ...em, let me clarify, baffles, speaker enclosures affect the sounds a speaker/drive unit produces to your ears as they resonate, they colour what you hear. Thickness, materials used resonate/vibrate at their own frequency.This in turn is the reason a speaker sounds different in different enclosures.

The frequency range of the speaker remains the same given a fixed signal.

example if 1watt fed to a free standing speaker shifts the cone 5mm producing frequencies between 10hz to 10khz, placed onto a baffle into a box measuring 30cm x 17cm x 20cm it will still provide the same frequency response if that 1watt is fed into the speaker and the cone will still only shift 5mm.

What you'll get is the added resonence of the enclosure around the speaker, the air shifting within the enclosure and its effects on the...er...enclosure walls, THIS will contribute to the sound you hear. This is what we buy.

so while I understand you may think the speaker/driver units characteristics/frequencies may change, infact they don't. You just get other frequencies added to what the speaker produces.

If measured externally i.e with a mic in the middle of your room, then yes frequencies will differ to a stand alone speaker, but if you measure the actual driver its frequencies/output remains the same. its an electrical device its simple maths.

 

[Thompsonuxb]

Oh....and this "however, that article is not about baffles. it's more about knowing how individual drivers measure so you can tell how music would sound reproduced by them." this makes no sense, there is a reason why multiple drivers are used these days. A single driver would struggle to reproduce a full frequencie range that would sound like the 'real thing'.

thats the reason the article is silly - the whole point of speaker technology is to reproduce sound to sound like the real thing, using harmonics and such, achieve the 'full frequencie range' if you will the only way to tell that is to listen to it, like most above are saying. the actual drive unit is only one part of a bigger whole,

 

[hoopsontoast]

No, oldric_naubhoff and hoopsontoast you guys are wrong.

eh ...em, let me clarify, baffles, speaker enclosures affect the sounds a speaker/drive unit produces to your ears as they resonate, they colour what you hear. Thickness, materials used resonate/vibrate at their own frequency.This in turn is the reason a speaker sounds different in different enclosures.

The frequency range of the speaker remains the same given a fixed signal.




example if 1watt fed to a free standing speaker shifts the cone 5mm producing frequencies between 10hz to 10khz, placed onto a baffle into a box measuring 30cm x 17cm x 20cm it will still provide the same frequency response if that 1watt is fed into the speaker and the cone will still only shift 5mm.

What you'll get is the added resonence of the enclosure around the speaker, the air shifting within the enclosure and its effects on the...er...enclosure walls, THIS will contribute to the sound you hear. This is what we buy.

so while I understand you may think the speaker/driver units characteristics/frequencies may change, infact they don't. You just get other frequencies added to what the speaker produces.

If measured externally i.e with a mic in the middle of your room, then yes frequencies will differ to a stand alone speaker, but if you measure the actual driver its frequencies/output remains the same. its an electrical device its simple maths.

No it wont, I am afraid. For example, a driver in an optimised tuned ported box will have more excursion at 1w input to the same driver in an optimised sealed box for the same given 1w input.

The Frequency response, CSD, Impulse Response and Theil Small Parameters will all change when a specific driver is placed any different box (or none for example in Open Baffle).

Its not maths by the way, its physics...

 

[oldric_naubhoff]

No, oldric_naubhoff and hoopsontoast you guys are wrong.

eh ...em, let me clarify, baffles, speaker enclosures affect the sounds a speaker/drive unit produces to your ears as they resonate, they colour what you hear. Thickness, materials used resonate/vibrate at their own frequency.This in turn is the reason a speaker sounds different in different enclosures.

The frequency range of the speaker remains the same given a fixed signal.




example if 1watt fed to a free standing speaker shifts the cone 5mm producing frequencies between 10hz to 10khz, placed onto a baffle into a box measuring 30cm x 17cm x 20cm it will still provide the same frequency response if that 1watt is fed into the speaker and the cone will still only shift 5mm.

What you'll get is the added resonence of the enclosure around the speaker, the air shifting within the enclosure and its effects on the...er...enclosure walls, THIS will contribute to the sound you hear. This is what we buy.

so while I understand you may think the speaker/driver units characteristics/frequencies may change, infact they don't. You just get other frequencies added to what the speaker produces.

If measured externally i.e with a mic in the middle of your room, then yes frequencies will differ to a stand alone speaker, but if you measure the actual driver its frequencies/output remains the same. its an electrical device its simple maths.

No it wont, I am afraid. For example, a driver in an optimised tuned ported box will have more excursion at 1w input to the same driver in an optimised sealed box for the same given 1w input.

The Frequency response, CSD, Impulse Response and Theil Small Parameters will all change when a specific driver is placed any different box (or none for example in Open Baffle).

Its not maths by the way, its physics...

I rest my case.

(thanks hoopsontoast )

 

[oldric_naubhoff]

Oh....and this "however, that article is not about baffles. it's more about knowing how individual drivers measure so you can tell how music would sound reproduced by them." this makes no sense, there is a reason why multiple drivers are used these days. A single driver would struggle to reproduce a full frequencie range that would sound like the 'real thing'.

thats the reason the article is silly - the whole point of speaker technology is to reproduce sound to sound like the real thing, using harmonics and such, achieve the 'full frequencie range' if you will the only way to tell that is to listen to it, like most above are saying. the actual drive unit is only one part of a bigger whole,

I think you underestimate the point that article tries to convey. while it's true it's the complete product we're buying (or trying to assemble) the complete product will only be as good as the sum of its parts. everything counts; enclosure design, crossover design and its quality and of course drivers themselves. the author of the article focuses on measuring quality of drivers. quite rightly so IMO, since the drivers are the most important parts of every speaker design. while designers of speakers may have some freedom with manipulating with output of drivers they choose to use to gain desirable effect, for instance highlighting certain frequencies to make speakers sound more engaging on quick listen (like boosting bass or presence region) there are qualities of drivers that are given and cannot be enhanced by clever engineering, only deteriorated. I'm particularly thinking of harmonic distortion measurement (obviously the lower the better) or CSD measurement which tell a lot how a driver will work in any given application. for instance high, audible harmonic distortion may be even desirable in some cases because it will make bass sound more "phat" or treble more "airy". obviously this is nothing but colouration and should be avoided but I can surely appreciate that some, surely non hi-fi, manufacturers may opt for such solutions. likewise CSD behavior. you want drivers which have no decay and no resonances. obviously this is not achievable because every driver has finite moving mass but at lest you can opt for the best in this regard if you want clean and fast sounding speaker.

that's in a nutshell. if you want to know more there's vast amount of information on the net explaining how measurements help evaluating quality of sound reproduction.

 

[AlmaataKZ]

If a system sounds good to your ears & you enjoying the sound, then no need for measurement.

I use different approach: use measurement etc (i.e. objective approach) to design accurate (i.e. neutral) and high prformance speakers and then play on it the music that sounds good to my ears.

 

[wireman]

My approach is simple: A good system has me tapping my feet, and a great system has me dancing (and that's not a pretty sight!).

 

[Thompsonuxb]

No, oldric_naubhoff and hoopsontoast you guys are wrong.

eh ...em, let me clarify, baffles, speaker enclosures affect the sounds a speaker/drive unit produces to your ears as they resonate, they colour what you hear. Thickness, materials used resonate/vibrate at their own frequency.This in turn is the reason a speaker sounds different in different enclosures.

The frequency range of the speaker remains the same given a fixed signal.




example if 1watt fed to a free standing speaker shifts the cone 5mm producing frequencies between 10hz to 10khz, placed onto a baffle into a box measuring 30cm x 17cm x 20cm it will still provide the same frequency response if that 1watt is fed into the speaker and the cone will still only shift 5mm.

What you'll get is the added resonence of the enclosure around the speaker, the air shifting within the enclosure and its effects on the...er...enclosure walls, THIS will contribute to the sound you hear. This is what we buy.

so while I understand you may think the speaker/driver units characteristics/frequencies may change, infact they don't. You just get other frequencies added to what the speaker produces.

If measured externally i.e with a mic in the middle of your room, then yes frequencies will differ to a stand alone speaker, but if you measure the actual driver its frequencies/output remains the same. its an electrical device its simple maths.

No it wont, I am afraid. For example, a driver in an optimised tuned ported box will have more excursion at 1w input to the same driver in an optimised sealed box for the same given 1w input.

The Frequency response, CSD, Impulse Response and Theil Small Parameters will all change when a specific driver is placed any different box (or none for example in Open Baffle).

Its not maths by the way, its physics...

No... that case cannot be rested yet.....lol.

the above example is a constant - 1watt = 10hz to 10khz= 5mm of movement of the driver.

Explain how that changes if placed in a cabinate, I mean would or could the frequencie response of the driver increase from 20hz to 20khz for example. same power same travel of the cone. Yes the cabinate can be tuned, but the drivers properties are constant. ITS like moving a speaker closer or further away from a back wall, the performance stays the same just the interaction of the frequencies on its surroundings change - not the out put of the speaker itself.

its like placing a bulb that produces 60watts of light from a 240volt supply. if placed in a room painted brilliant white it appears brighter than if placed in a room painted matt black. The output i.e the amount of light remains the same. but the reflextiveness of the rooms effect what you see.

You confuse the effects the speaker has on the boxes (vibration & movement of air etc) to what the speaker/drive unit produces. fact is it performs exactly the same in all situations 10hz to 10khz from 1watt and 5mm shift of the cone.

 

[Thompsonuxb]

Oh....and this "however, that article is not about baffles. it's more about knowing how individual drivers measure so you can tell how music would sound reproduced by them." this makes no sense, there is a reason why multiple drivers are used these days. A single driver would struggle to reproduce a full frequencie range that would sound like the 'real thing'.

thats the reason the article is silly - the whole point of speaker technology is to reproduce sound to sound like the real thing, using harmonics and such, achieve the 'full frequencie range' if you will the only way to tell that is to listen to it, like most above are saying. the actual drive unit is only one part of a bigger whole,

I think you underestimate the point that article tries to convey. while it's true it's the complete product we're buying (or trying to assemble) the complete product will only be as good as the sum of its parts. everything counts; enclosure design, crossover design and its quality and of course drivers themselves. the author of the article focuses on measuring quality of drivers. quite rightly so IMO, since the drivers are the most important parts of every speaker design. while designers of speakers may have some freedom with manipulating with output of drivers they choose to use to gain desirable effect, for instance highlighting certain frequencies to make speakers sound more engaging on quick listen (like boosting bass or presence region) there are qualities of drivers that are given and cannot be enhanced by clever engineering, only deteriorated. I'm particularly thinking of harmonic distortion measurement (obviously the lower the better) or CSD measurement which tell a lot how a driver will work in any given application. for instance high, audible harmonic distortion may be even desirable in some cases because it will make bass sound more "phat" or treble more "airy". obviously this is nothing but colouration and should be avoided but I can surely appreciate that some, surely non hi-fi, manufacturers may opt for such solutions. likewise CSD behavior. you want drivers which have no decay and no resonances. obviously this is not achievable because every driver has finite moving mass but at lest you can opt for the best in this regard if you want clean and fast sounding speaker.

that's in a nutshell. if you want to know more there's vast amount of information on the net explaining how measurements help evaluating quality of sound reproduction.

what you've just written makes the article mute then.

ultimately its about the design (isn't that what you are saying) hence forth the actual driver is not the be all and end all, thats why we have various materials port solotions and such to achieve the 'best sound' and why multiple drivers are used to produce those harmonics - its also why speaker positioning suggestions are provide by manufactors.

Funny thing is practically any speaker can provide a decent sound if given a clean signal and decent support (stands). the article is stupid in its attempt to belittle unbiased assesment of a given design - by trying to remove all the time and work put into creating "a sound" to talk about the the drivers alone.

 

[busb]

Oh....and this "however, that article is not about baffles. it's more about knowing how individual drivers measure so you can tell how music would sound reproduced by them." this makes no sense, there is a reason why multiple drivers are used these days. A single driver would struggle to reproduce a full frequencie range that would sound like the 'real thing'.

thats the reason the article is silly - the whole point of speaker technology is to reproduce sound to sound like the real thing, using harmonics and such, achieve the 'full frequencie range' if you will the only way to tell that is to listen to it, like most above are saying. the actual drive unit is only one part of a bigger whole,

I think you underestimate the point that article tries to convey. while it's true it's the complete product we're buying (or trying to assemble) the complete product will only be as good as the sum of its parts. everything counts; enclosure design, crossover design and its quality and of course drivers themselves. the author of the article focuses on measuring quality of drivers. quite rightly so IMO, since the drivers are the most important parts of every speaker design. while designers of speakers may have some freedom with manipulating with output of drivers they choose to use to gain desirable effect, for instance highlighting certain frequencies to make speakers sound more engaging on quick listen (like boosting bass or presence region) there are qualities of drivers that are given and cannot be enhanced by clever engineering, only deteriorated. I'm particularly thinking of harmonic distortion measurement (obviously the lower the better) or CSD measurement which tell a lot how a driver will work in any given application. for instance high, audible harmonic distortion may be even desirable in some cases because it will make bass sound more "phat" or treble more "airy". obviously this is nothing but colouration and should be avoided but I can surely appreciate that some, surely non hi-fi, manufacturers may opt for such solutions. likewise CSD behavior. you want drivers which have no decay and no resonances. obviously this is not achievable because every driver has finite moving mass but at lest you can opt for the best in this regard if you want clean and fast sounding speaker.

that's in a nutshell. if you want to know more there's vast amount of information on the net explaining how measurements help evaluating quality of sound reproduction.

what you've just written makes the article mute then.

ultimately its about the design (isn't that what you are saying) hence forth the actual driver is not the be all and end all, thats why we have various materials port solotions and such to achieve the 'best sound' and why multiple drivers are used to produce those harmonics - its also why speaker positioning suggestions are provide by manufactors.

Funny thing is practically any speaker can provide a decent sound if given a clean signal and decent support (stands). the article is stupid in its attempt to belittle unbiased assesment of a given design - by trying to remove all the time and work put into creating "a sound" to talk about the the drivers alone.

The quoted piece isn't particularly well written, IMO. However the auther is saying that you cannot make a silk purse out of a sow's ear & that that individual elements such as drivers need to be fit for the purpose. The manufacturer of any drivers will publish measured results they then give as specifications for speaker makers to use for selecting suitable models. The speaker manufacturer will probably make their own measurements on the drive units themselves, especially when buying from an unfamiliar manufacturer. Based on these measurements, they can then proceed with fine-tuning cabinet design, cross-over characteristics, port tuning etc. At some point listening tests (voicing) will require some tweeking of the design to a lesser or greater extent.

As for for driver displacement for a given input amplitude & frequency, this will depend on the impedance of the air that will change from when the driver is measured in free space compared with being mounted in a cabinet. In other words, air has mass & volume - back pressure will increase impedance or the ability of the cone to move as easily as it would in free space. This characteristic will change with frequency. Another point to remember is that some frequencies are shared between two drivers around the cross-over region that can either reinforce or cancel each other out. The bandwidth of these shared frequencies also depends on the steepness of the filtering. Crossover design can have few elements for shallow filtering or be very complex for a sharp cutoff. Sharp cutoff filters are usually very complex to lessen phase variations. Very steep filters are called brickwall & have high amounts of phase shift & generally avoided where possible.

 

[Thompsonuxb]

Oh....and this "however, that article is not about baffles. it's more about knowing how individual drivers measure so you can tell how music would sound reproduced by them." this makes no sense, there is a reason why multiple drivers are used these days. A single driver would struggle to reproduce a full frequencie range that would sound like the 'real thing'.

thats the reason the article is silly - the whole point of speaker technology is to reproduce sound to sound like the real thing, using harmonics and such, achieve the 'full frequencie range' if you will the only way to tell that is to listen to it, like most above are saying. the actual drive unit is only one part of a bigger whole,

I think you underestimate the point that article tries to convey. while it's true it's the complete product we're buying (or trying to assemble) the complete product will only be as good as the sum of its parts. everything counts; enclosure design, crossover design and its quality and of course drivers themselves. the author of the article focuses on measuring quality of drivers. quite rightly so IMO, since the drivers are the most important parts of every speaker design. while designers of speakers may have some freedom with manipulating with output of drivers they choose to use to gain desirable effect, for instance highlighting certain frequencies to make speakers sound more engaging on quick listen (like boosting bass or presence region) there are qualities of drivers that are given and cannot be enhanced by clever engineering, only deteriorated. I'm particularly thinking of harmonic distortion measurement (obviously the lower the better) or CSD measurement which tell a lot how a driver will work in any given application. for instance high, audible harmonic distortion may be even desirable in some cases because it will make bass sound more "phat" or treble more "airy". obviously this is nothing but colouration and should be avoided but I can surely appreciate that some, surely non hi-fi, manufacturers may opt for such solutions. likewise CSD behavior. you want drivers which have no decay and no resonances. obviously this is not achievable because every driver has finite moving mass but at lest you can opt for the best in this regard if you want clean and fast sounding speaker.

that's in a nutshell. if you want to know more there's vast amount of information on the net explaining how measurements help evaluating quality of sound reproduction.

what you've just written makes the article mute then.

ultimately its about the design (isn't that what you are saying) hence forth the actual driver is not the be all and end all, thats why we have various materials port solotions and such to achieve the 'best sound' and why multiple drivers are used to produce those harmonics - its also why speaker positioning suggestions are provide by manufactors.

Funny thing is practically any speaker can provide a decent sound if given a clean signal and decent support (stands). the article is stupid in its attempt to belittle unbiased assesment of a given design - by trying to remove all the time and work put into creating "a sound" to talk about the the drivers alone.

The quoted piece isn't particularly well written, IMO. However the auther is saying that you cannot make a silk purse out of a sow's ear & that that individual elements such as drivers need to be fit for the purpose. The manufacturer of any drivers will publish measured results they then give as specifications for speaker makers to use for selecting suitable models. The speaker manufacturer will probably make their own measurements on the drive units themselves, especially when buying from an unfamiliar manufacturer. Based on these measurements, they can then proceed with fine-tuning cabinet design, cross-over characteristics, port tuning etc. At some point listening tests (voicing) will require some tweeking of the design to a lesser or greater extent.

As for for driver displacement for a given input amplitude & frequency, this will depend on the impedance of the air that will change from when the driver is measured in free space compared with being mounted in a cabinet. In other words, air has mass & volume - back pressure will increase impedance or the ability of the cone to move as easily as it would in free space. This characteristic will change with frequency. Another point to remember is that some frequencies are shared between two drivers around the cross-over region that can either reinforce or cancel each other out. The bandwidth of these shared frequencies also depends on the steepness of the filtering. Crossover design can have few elements for shallow filtering or be very complex for a sharp cutoff. Sharp cutoff filters are usually very complex to lessen phase variations. Very steep filters are called brickwall & have high amounts of phase shift & generally avoided where possible.

but we can make a purse out of the pigs hear & while it may not be as pretty it'll probably outlast the silk purse......crazy.

not sure if you're agreeing with me or otherwise, but your contribution also makes it clear there is more to speaker design than just the drivers and there 'quality' and again kinda puts the peice into a context.

 

[busb]

Many years back, I went to a local college. The food in the canteen was cooked by students studying cooking. The food wasn't that great. After a while, I realised that no one could create decent meals from cheap ingredients whatever care they took.

 

[Thompsonuxb]

Many years back, I went to a local college. The food in the canteen was cooked by students studying cooking. The food wasn't that great. After a while, I realised that no one could create decent meals from cheap ingredients whatever care they took.

Thats a lie..... some people I swear.

You eat takeaways, a little salt, some black pepper a smiggin of vinigar and lots of hot sauce you can create a decent meal out of almost anything. You might 2h1^ yourself the following morning but while it last you're in cheap ingredients heaven.

 

[busb]

Many years back, I went to a local college. The food in the canteen was cooked by students studying cooking. The food wasn't that great. After a while, I realised that no one could create decent meals from cheap ingredients whatever care they took.

Thats a lie..... some people I swear.

You eat takeaways, a little salt, some black pepper a smiggin of vinigar and lots of hot sauce you can create a decent meal out of almost anything. You might 2h1^ yourself the following morning but while it last you're in cheap ingredients heaven.

that explains a lot!

 

[VoodooDoctor]

Opinion piece at Audioholics:

http://www.audioholics.com/news/editorials/science-loudspeakers

 

[busb]

Opinion piece at Audioholics:

http://www.audioholics.com/news/editorials/science-loudspeakers

Petty sound I'd say. One conclusion that could could be drawn is that the only people who trust HiFi manufacturers marketing depts are out & out subjectivist flat-earthers!

On a more serious point the article suggests that many measurements are I'll-conceived but expects reviewers to do some. I can't remember reading any threads on this board where members have proclaimed that one speaker is better than another based on measurements. I'd suggest most people don't consider themselves to be totally "objectivist" or "subjectivist" anyway.

(unpublished by mods - duplicate)

 

[busb]

Opinion piece at Audioholics:

http://www.audioholics.com/news/editorials/science-loudspeakers

Petty sound I'd say. One conclusion that could could be drawn is that the only people who trust HiFi manufacturers marketing depts are out & out subjectivist flat-earthers!

On a more serious point the article suggests that many measurements are I'll-conceived but expects reviewers to do some. I can't remember reading any threads on this board where members have proclaimed that one speaker is better than another based on measurements. I'd suggest most people don't consider themselves to be totally "objectivist" or "subjectivist" anyway.

 

[hoopsontoast]

No, oldric_naubhoff and hoopsontoast you guys are wrong.

eh ...em, let me clarify, baffles, speaker enclosures affect the sounds a speaker/drive unit produces to your ears as they resonate, they colour what you hear. Thickness, materials used resonate/vibrate at their own frequency.This in turn is the reason a speaker sounds different in different enclosures.

The frequency range of the speaker remains the same given a fixed signal.




example if 1watt fed to a free standing speaker shifts the cone 5mm producing frequencies between 10hz to 10khz, placed onto a baffle into a box measuring 30cm x 17cm x 20cm it will still provide the same frequency response if that 1watt is fed into the speaker and the cone will still only shift 5mm.

What you'll get is the added resonence of the enclosure around the speaker, the air shifting within the enclosure and its effects on the...er...enclosure walls, THIS will contribute to the sound you hear. This is what we buy.

so while I understand you may think the speaker/driver units characteristics/frequencies may change, infact they don't. You just get other frequencies added to what the speaker produces.

If measured externally i.e with a mic in the middle of your room, then yes frequencies will differ to a stand alone speaker, but if you measure the actual driver its frequencies/output remains the same. its an electrical device its simple maths.

No it wont, I am afraid. For example, a driver in an optimised tuned ported box will have more excursion at 1w input to the same driver in an optimised sealed box for the same given 1w input.

The Frequency response, CSD, Impulse Response and Theil Small Parameters will all change when a specific driver is placed any different box (or none for example in Open Baffle).

Its not maths by the way, its physics...

No... that case cannot be rested yet.....lol.

the above example is a constant - 1watt = 10hz to 10khz= 5mm of movement of the driver.

Explain how that changes if placed in a cabinate, I mean would or could the frequencie response of the driver increase from 20hz to 20khz for example. same power same travel of the cone. Yes the cabinate can be tuned, but the drivers properties are constant. ITS like moving a speaker closer or further away from a back wall, the performance stays the same just the interaction of the frequencies on its surroundings change - not the out put of the speaker itself.

its like placing a bulb that produces 60watts of light from a 240volt supply. if placed in a room painted brilliant white it appears brighter than if placed in a room painted matt black. The output i.e the amount of light remains the same. but the reflextiveness of the rooms effect what you see.

You confuse the effects the speaker has on the boxes (vibration & movement of air etc) to what the speaker/drive unit produces. fact is it performs exactly the same in all situations 10hz to 10khz from 1watt and 5mm shift of the cone.

Please, just have a look online, read some books. Learn about speaker design theory.

A driver in open baffle (free air) will produce more excursion and distortion at a specific level if that very same driver was in an optimised sealed box with the same input. A ported/tuned box will be in-between.

You can asses individual drivers to get a clear base line comparison for their specifications like Frequency Response, CSD, Theil Small Parameters, Distortion etc (Like Zaph does in that original link). You can then take those bits of information to chose which drivers to use in your speaker design. You can then with those drivers, design a crossover (if you need one) and a cabinet (if you need one) then fine tune it to your hearts content.

 

[Thompsonuxb]

No, oldric_naubhoff and hoopsontoast you guys are wrong.

eh ...em, let me clarify, baffles, speaker enclosures affect the sounds a speaker/drive unit produces to your ears as they resonate, they colour what you hear. Thickness, materials used resonate/vibrate at their own frequency.This in turn is the reason a speaker sounds different in different enclosures.

The frequency range of the speaker remains the same given a fixed signal.




example if 1watt fed to a free standing speaker shifts the cone 5mm producing frequencies between 10hz to 10khz, placed onto a baffle into a box measuring 30cm x 17cm x 20cm it will still provide the same frequency response if that 1watt is fed into the speaker and the cone will still only shift 5mm.

What you'll get is the added resonence of the enclosure around the speaker, the air shifting within the enclosure and its effects on the...er...enclosure walls, THIS will contribute to the sound you hear. This is what we buy.

so while I understand you may think the speaker/driver units characteristics/frequencies may change, infact they don't. You just get other frequencies added to what the speaker produces.

If measured externally i.e with a mic in the middle of your room, then yes frequencies will differ to a stand alone speaker, but if you measure the actual driver its frequencies/output remains the same. its an electrical device its simple maths.

No it wont, I am afraid. For example, a driver in an optimised tuned ported box will have more excursion at 1w input to the same driver in an optimised sealed box for the same given 1w input.

The Frequency response, CSD, Impulse Response and Theil Small Parameters will all change when a specific driver is placed any different box (or none for example in Open Baffle).

Its not maths by the way, its physics...

No... that case cannot be rested yet.....lol.

the above example is a constant - 1watt = 10hz to 10khz= 5mm of movement of the driver.

Explain how that changes if placed in a cabinate, I mean would or could the frequencie response of the driver increase from 20hz to 20khz for example. same power same travel of the cone. Yes the cabinate can be tuned, but the drivers properties are constant. ITS like moving a speaker closer or further away from a back wall, the performance stays the same just the interaction of the frequencies on its surroundings change - not the out put of the speaker itself.

its like placing a bulb that produces 60watts of light from a 240volt supply. if placed in a room painted brilliant white it appears brighter than if placed in a room painted matt black. The output i.e the amount of light remains the same. but the reflextiveness of the rooms effect what you see.

You confuse the effects the speaker has on the boxes (vibration & movement of air etc) to what the speaker/drive unit produces. fact is it performs exactly the same in all situations 10hz to 10khz from 1watt and 5mm shift of the cone.

Please, just have a look online, read some books. Learn about speaker design theory.

A driver in open baffle (free air) will produce more excursion and distortion at a specific level if that very same driver was in an optimised sealed box with the same input. A ported/tuned box will be in-between.

You can asses individual drivers to get a clear base line comparison for their specifications like Frequency Response, CSD, Theil Small Parameters, Distortion etc (Like Zaph does in that original link). You can then take those bits of information to chose which drivers to use in your speaker design. You can then with those drivers, design a crossover (if you need one) and a cabinet (if you need one) then fine tune it to your hearts content.

What do you think I'm saying?

a speaker performs to its design parameters, the use of boxes, crossovers, ports etc is to tune its sound or its output for sound reproduction to 'taste'.

a free standing speaker will sound different in the middle of a room than if its placed in the corner of the room or placed close to a wall - whats affected is the air/soundwaves the speaker is shifting or the air/frequncies interaction with surfaces around it. The speaker does not alter its output nor is the frequencies it produces altered. I tried to use the light bulb analgy to clarify.

as I've said the placment of a speaker - boxed, ported or what ever effects its sound, the speaker output if measured stays the same - what you hear does change.

I believe we are saying the same thing, but you guys struggle to seperate what the driver is doing to the affects on the sound it produces in an enclosure, room, corner etc.

bout go read a book.....prrrft!