Børresen M1

[Pearljam5000]

What Drivers Do They Use? – Kii Audio / Kii Three

The Kii Audio Kii Three, is a briliant construction and innovation setting new standards for a small speaker this size. Brain child of not least Bruno Putzeys, the inventor of the UcD class D ampli…

www.sensibleaudio.dk

Wow 12€ drivers according to the website

 

[a4eaudio]

i see units ranging from about 1200 USD to 18 USD
can we say that the more expensive one is superior ?

Yes the $1,200 driver is superior to the $18 driver. But that is not the interesting question. Is the $500 driver superior to the $250 driver? By how much and in what ways? Is the $250 driver superior to the $80 driver? By how much and in what ways?

 

[gino1961]

Yes the $1,200 driver is superior to the $18 driver. But that is not the interesting question. Is the $500 driver superior to the $250 driver? By how much and in what ways? Is the $250 driver superior to the $80 driver? By how much and in what ways?

actually this is what i would like to know/understand I have the feeling that just looking at the datasheets is not enough Some very important info are missing
Personally after FR flatness and reasonable sensitivity i would love to know about IMD THD values vs SPLs and CSD behaviour Most of the time they are not provided
Some units seem clearly ok They exude quality In the old days i was a fun of very low Qts units Like Scanspeak Values of 0,2 were not uncommon
They are not cheap clearly Another way is to look what well received speakers use I wonder which could be the best source of drivers in EU
in USA i see often mentioned Parts Express But i am in EU

 

[Killingbeans]

Hi thanks a lot for the very kind and valuable advice
just to be sure to understand I copy a freq response of a driver here below
View attachment 412400
at what Hz the break-up starts ? or better up to which Hz this driver shows a pistonic motion ?

Looks like it starts kicking in at around 6kHz. Fairly benignly though.

BTW, you guys are more than welcome to correct me if I'm talking out of my ass (It wouldn't be the first time).

EDIT: Is it a Scan-speak 10F/8424G00?

 

[dfuller]

Wow 12€ drivers according to the website

Yep. Even pretty damn cheap drivers can be made to perform very well.

(That's not to say there isn't a place for more expensive drivers, Purifi for example has absolutely insane excursion capabilities that you can't get with cheaper drivers)

 

[Mart68]

Looks like it starts kicking in at around 6kHz. Fairly benignly though.

BTW, you guys are more than welcome to correct me if I'm talking out of my ass (It wouldn't be the first time).

To break up I'd agree. Where it stops being 'pistonic' I don't have a scooby. Would you need a distortion measurement for that?

 

[a4eaudio]

I have the feeling that just looking at the datasheets is not enough Some very important info are missing
Personally after FR flatness and reasonable sensitivity i would love to know about IMD THD values vs SPLs and CSD behaviour Most of the time they are not provided

I don't consider sensitivity an attribute of quality, it is just a result of the design tradeoffs made.
Distortion and IMD are important and you probably have to rely on third-party measurements - AudioXpress, HiFicompass, etc. But don't get too obsessed either - does it really matter if 3rd order harmonic distortion is down 47db vs 50db over a quarter of an octave?

I wonder which could be the best source of drivers in EU in USA i see often mentioned Parts Express

Part Express is the LARGEST distributor of drivers in the USA but Madisound is the distributor of some of the higher end brands like Scan-speak, Seas, SB Acoustics, Purifi, Accuton, etc.

I live in the USA but know https://www.soundimports.eu and https://en.toutlehautparleur.com/speakers.html carry a lot of drivers.

 

[voodooless]

Where it stops being 'pistonic' I don't have a scooby. Would you need a distortion measurement for that?

It can be lots of things, distortion, IMD, energy storage, loss of directivity. And usually these happen also with loss of directivity but to physical size as well, so effects mix and merge. For this type of driver, I would guess it’s between 1 and 2 kHz.

 

[Pearljam5000]

Yep. Even pretty damn cheap drivers can be made to perform very well.

(That's not to say there isn't a place for more expensive drivers, Purifi for example has absolutely insane excursion capabilities that you can't get with cheaper drivers)

How much does the ATC drivers cost?

 

[dfuller]

How much does the ATC drivers cost?

They don't sell them to the public any more - when they did they were eye-wateringly expensive. Very high performance parts though, because ATC actually understands how to build high performance drivers... unlike Borresen.

 

[gino1961]

I don't consider sensitivity an attribute of quality, it is just a result of the design tradeoffs made.
Distortion and IMD are important and you probably have to rely on third-party measurements - AudioXpress, HiFicompass, etc. But don't get too obsessed either - does it really matter if 3rd order harmonic distortion is down 47db vs 50db over a quarter of an octave?

Hi thank you very much and sorry for the belated reply but i did not receive the notification
Yes after the FR i look for CSD IMD and THD mainly As you say usually these measurements are carried out only by third parties
Usually for any other industrial product the specifications are enough for the design phase
With drivers also for simulating a FR but there is no data available that can be correlated to the actual sound quality Some designers even listen to drivers for selection
Unbelievable lack of scientific attitude
I find really strange that designers have not developed a set of original measurements that can be correlated with the sound quality of the drivers
maybe they have but it could be a secret ?

Part Express is the LARGEST distributor of drivers in the USA but Madisound is the distributor of some of the higher end brands like Scan-speak, Seas, SB Acoustics, Purifi, Accuton, etc.
I live in the USA but know https://www.soundimports.eu and https://en.toutlehautparleur.com/speakers.html carry a lot of drivers.

thank you so much I am looking at the 1st link you mention and the choice is really huge
I have also another long term obsession My ideal speaker could be a 3 ways I do not know what could be the optimal cross point between woofer and mid
Looking at commercial speakers i have found from as low as 100Hz up to 1000Hz
i am getting mad

 

[Killingbeans]

Looking at commercial speakers i have found from as low as 100Hz up to 1000Hz

1000Hz is asking for trouble, IMO.

Ideally you'd want the midrange to handle as much of the spectrum as possible, but then you risk issues with doppler distortion and directivity errors.

It all depends on the quality and capabilities of the drivers and the compromises you're willing to accept.

 

[gino1961]

1000Hz is asking for trouble, IMO.

Hi thank you very much This is an extreme of course I saw in a JBL monitor i think

Ideally you'd want the midrange to handle as much of the spectrum as possible, but then you risk issues with doppler distortion and directivity errors.
It all depends on the quality and capabilities of the drivers and the compromises you're willing to accept.

i agree the midrange performance is key for great sound
but the question is which are the lower and upper limits of the midrange ?
when you have answered this question you can start look for a suitable driver to cover the range
I have seen fullrange, 4 to 8 inches cones and 2 to 3 inches domes drivers used in 3 ways
All equally good ?
my biggest nightmare is that the voice is in the same range of drums
How can a same driver playback a weak voice and loud drums at the same time without distortion ???
it seems to me impossible
As i sad it is my biggest nightmare

 

[Killingbeans]

Hi thank you very much This is an extreme of course I saw in a JBL monitor i think

Are you sure it wasn't a two way?

i agree the midrange performance is key for great sound
but the question is which are the lower and upper limits of the midrange ?
when you have answered this question you can start look for a suitable driver to cover the range

No upper or lower limits.

There are plenty of people who worship single driver "full range" speakers, despite their glaring issues.

You set the limits depending on how many of these issuses you want to remedy and to what degree. having to place multiple driver on an enclosure and introducing a crossover to the chain gives a new set of issues.

It's all about compromises and design goals.

I have seen fullrange, 4 to 8 inches cones and 2 to 3 inches domes drivers used in 3 ways
All equally good ?

Yes. Again, it depends on how you define "good".

my biggest nightmare is that the voice is in the same range of drums
How can a same driver playback a weak voice and loud drums at the same time without distortion ???
it seems to me impossible
As i sad it is my biggest nightmare

That's not something you need to fear.

A loud sound will mask a weak sound, but that's not distortion. It's just how sound works. You can't avoid it, even when listening to live music.

Doppler distortion stems from a single driver reproducing two very different frequencies at the same time. It's not determined by SPL.

 

[gino1961]

Are you sure it wasn't a two way?

https://www.hifiengine.com/manual_library/jbl/l166.shtml

midrange starting from 1kHz

No upper or lower limits.
There are plenty of people who worship single driver "full range" speakers, despite their glaring issues.

Yes but i am afraid i could not stand breakups Actually i am looking at nice little fullrange from Faital Pro 3 and 4" units
almost all have a strong peak at around 10kHz This worries me for using full range
of course they are fine above 300Hz

You set the limits depending on how many of these issuses you want to remedy and to what degree.
having to place multiple driver on an enclosure and introducing a crossover to the chain gives a new set of issues.

Yes i will keep the big woofer in a separated cabinet Something like Wilson Audio does with their Watt and Puppy
this is my reference concept A dream

It's all about compromises and design goals.
Yes. Again, it depends on how you define "good".

extremely low in THD and IMD even during musical peaks and hopefully flat

That's not something you need to fear.
A loud sound will mask a weak sound, but that's not distortion. It's just how sound works. You can't avoid it, even when listening to live music.
Doppler distortion stems from a single driver reproducing two very different frequencies at the same time. It's not determined by SPL.

Yes you are very right A singer and a drum will always play in the same freq band
This is very challenging
I mentioned the old JBL L166 because i loved their sound
I start to think that the important band is from 100 to 1500Hz
to cover it with a single driver a 8" woofer is needed
i am stil studying Gathering information
Thank you very much again
Kind regards
gino

 

[Bach]

$ 100.000: What, so little for so much good stuff?

 

[Mart68]

https://www.hifiengine.com/manual_library/jbl/l166.shtml

midrange starting from 1kHz

Yes but i am afraid i could not stand breakups Actually i am looking at nice little fullrange from Faital Pro 3 and 4" units
almost all have a strong peak at around 10kHz This worries me for using full range
of course they are fine above 300Hz

Yes i will keep the big woofer in a separated cabinet Something like Wilson Audio does with their Watt and Puppy
this is my reference concept A dream

extremely low in THD and IMD even during musical peaks and hopefully flat

Yes you are very right A singer and a drum will always play in the same freq band
This is very challenging
I mentioned the old JBL L166 because i loved their sound
I start to think that the important band is from 100 to 1500Hz
to cover it with a single driver a 8" woofer is needed
i am stil studying Gathering information
Thank you very much again
Kind regards
gino

I'm currently deploying these speakers which use Faital Pro 8 inch mids:

Faital-3WC-15

Not sure how big you want to go; they are large but to my mind the obvious sacrifice to make with Hoffman's Iron Law is the 'Small size'.

I also very much like the JBL L166 so maybe we have similar tastes/expectations?

 

[kemmler3D]

How can a same driver playback a weak voice and loud drums at the same time without distortion ???

In one sense it can't because of Doppler distortion, and unfortunately drums also tend to come from all drivers at once because they are broadband.

The good news is that this is not an inherent problem as @Killingbeans explains.

If you are looking for the lowest distortion and want to keep frequency ranges separate, you can use Purifi drivers and implement very steep crossover slopes using Hypex plate amps. The latter technique isn't very popular but if you also take care with phase distortion I don't think there are fundamental reasons not to.

 

[dfuller]

In one sense it can't because of Doppler distortion, and unfortunately drums also tend to come from all drivers at once because they are broadband.

The good news is that this is not an inherent problem as @Killingbeans explains.

If you are looking for the lowest distortion and want to keep frequency ranges separate, you can use Purifi drivers and implement very steep crossover slopes using Hypex plate amps. The latter technique isn't very popular but if you also take care with phase distortion I don't think there are fundamental reasons not to.

If distortion is what is cared about, a PTT10 in a ported enclosure with waveguided bliesma mid and tweeter is probably the way to go, along with Hypex plate amps doing LR4 slopes.

 

[Frank Dernie]

That being said. I still dream about using finite element methods for actual innovation. For instance for designing a BMR driver that has a ruler flat frequency response in the useable range, but also functions as a steep mechanical bandpass filter.

The BMR was developed using FE methods

It is very complex dynamically and pretty well impossible to manufacture economically to be ideal since a simple thing like the bonding of the surround can have a huge influence on the HF performance so the accuracy required is orders of magnitude higher than similar sized mid drivers. That is just one of the complexities.
Getting a perfect design is one thing, setting practical manufacturing tolerances for production is another and with some things, including BMR, pretty well makes them impractical.

I remember reading about cycloidal profile gears and how much more load they can transmit than involutes everybody uses this is entirely because involutes are tolerant of small misalignment or flex but cycloidal are not at all. So nobody went ahead with series production the theoretical benefits can not be maintained in production.

BMR is not that bad but I remember being told (I am friends with one of the developers) that after the prototypes were signed off the first trial production batch did not have a single usable unit in it.