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2-way Unity horn 250hz-20khz

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snowflake View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote snowflake Quote  Post ReplyReply Direct Link To This Post Posted: 30 September 2020 at 10:33pm
this all rather depends on what mids you use and what impedance you make for the mid section but:

if you end up padding down your tweeter you can put a bypass cap on the series resistor of the L-pad and effectively put in a high shelf equivalent to the gain reduction that the pad puts on the the tweeter. this will then dictate which tweeter you choose and how much HF roll-off it has.

I'm not sure what T.D. means about a paralell inductor in that diyaudio thread so maybe there is a completely different way to go about this.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote fatfreddiescat Quote  Post ReplyReply Direct Link To This Post Posted: 01 October 2020 at 9:04am
Originally posted by snowflake snowflake wrote:



I'm not sure what T.D. means about a paralell inductor in that diyaudio thread so maybe there is a completely different way to go about this.

My take on it is that the inductor is pat of the highpass filter, by being directly connected across the driver terminals it effectively shorts the driver out at low frequencies, hence damping any diaphragm movement caused by the other drivers in the waveguide. With a capacitor in series the driver is effectively decoupled from the amp.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote citizensc Quote  Post ReplyReply Direct Link To This Post Posted: 01 October 2020 at 10:39am
Originally posted by Elliot Thompson Elliot Thompson wrote:

Originally posted by citizensc citizensc wrote:

Its not that I want the one with the most output beyond 10k, Its just that I am a little concerned that the HF1440 will have so little output beyond 10k that it will be impractical to EQ it. I suspect this will not be the case, that's why I am willing to try it. 


I understood exactly what you meant.

Bear in mind for every boost you add in terms of equalisation, increases the power requirement to attain the desired output level, that will sound pleasing to your ears. Both companies offer impedance graphs. So that is one obstacle you've overcome. The next obstacle would be to determine which driver offers the lowest Le figures. Once you get those figures, you will be able to determine which driver will require the least amount of dB boost in terms of EQ to attain the desired high frequency needed which, will sound pleasing to your ears.

Best Regards,


By this do you just mean the simple Le value in mH as published on the B&C website? Or the Klippel model which includes Le2 and Re2? 

I understand that inductance impacts on the HF response of a driver, even in the context of subwoofers (look at the B&C DS series drivers) but this cant be the sole determinant of HF response in a compression driver can it? Not with how many other variables there are? Do we not have to take phase plug geometry, compression ratio, reflectors, diaphragm material, diaphragm geometry among other things in to account as well? 


With regards to passive crossovers, right now my focus is to get the horn to work acoustically and just use DSP (Linea ASC48). Once I have figured that part out, I may attempt to build a passive xover. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote snowflake Quote  Post ReplyReply Direct Link To This Post Posted: 01 October 2020 at 11:59am
Originally posted by fatfreddiescat fatfreddiescat wrote:

Originally posted by snowflake snowflake wrote:



I'm not sure what T.D. means about a paralell inductor in that diyaudio thread so maybe there is a completely different way to go about this.

My take on it is that the inductor is pat of the highpass filter, by being directly connected across the driver terminals it effectively shorts the driver out at low frequencies, hence damping any diaphragm movement caused by the other drivers in the waveguide. With a capacitor in series the driver is effectively decoupled from the amp.


so you can make a first order filter like this with just an indcutor in parallel (though even with an L-pad it's going to draw significant power out of passband).

but isn't this also true of all even-order passive filters? - the Le is paralell with the driver will short at low frequencies and damp the tweeter with back-EMF.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote fatfreddiescat Quote  Post ReplyReply Direct Link To This Post Posted: 01 October 2020 at 2:27pm
Originally posted by snowflake snowflake wrote:

Originally posted by fatfreddiescat fatfreddiescat wrote:

Originally posted by snowflake snowflake wrote:



I'm not sure what T.D. means about a paralell inductor in that diyaudio thread so maybe there is a completely different way to go about this.

My take on it is that the inductor is pat of the highpass filter, by being directly connected across the driver terminals it effectively shorts the driver out at low frequencies, hence damping any diaphragm movement caused by the other drivers in the waveguide. With a capacitor in series the driver is effectively decoupled from the amp.


so you can make a first order filter like this with just an indcutor in parallel (though even with an L-pad it's going to draw significant power out of passband).

but isn't this also true of all even-order passive filters? - the Le is paralell with the driver will short at low frequencies and damp the tweeter with back-EMF.
Exactly that, though the inductor wouldn't necessarily be directly accross the driver in the case of a 3rd order filter or if followed by an L pad etc. If the driver were to be connected directly to the outputs of an amp then then the amps damping factor will do the job.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote fatfreddiescat Quote  Post ReplyReply Direct Link To This Post Posted: 01 October 2020 at 2:37pm
Originally posted by fatfreddiescat fatfreddiescat wrote:

Originally posted by snowflake snowflake wrote:

Originally posted by fatfreddiescat fatfreddiescat wrote:

Originally posted by snowflake snowflake wrote:



I'm not sure what T.D. means about a paralell inductor in that diyaudio thread so maybe there is a completely different way to go about this.

My take on it is that the inductor is pat of the highpass filter, by being directly connected across the driver terminals it effectively shorts the driver out at low frequencies, hence damping any diaphragm movement caused by the other drivers in the waveguide. With a capacitor in series the driver is effectively decoupled from the amp.


so you can make a first order filter like this with just an indcutor in parallel (though even with an L-pad it's going to draw significant power out of passband).

but isn't this also true of all even-order passive filters? - the Le is paralell with the driver will short at low frequencies and damp the tweeter with back-EMF.
Exactly that, though the inductor wouldn't necessarily be directly accross the driver in the case of a 3rd order filter or if followed by an L pad etc. If the driver were to be connected directly to the outputs of an amp then then the amps damping factor will do the job. 

PS would love to come and have a listen to ur sounds when all this lockdown malarkey has passed, we were planning on doing a night in Bristol with my system this year until it turned into a washout.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote snowflake Quote  Post ReplyReply Direct Link To This Post Posted: 01 October 2020 at 9:30pm
Originally posted by fatfreddiescat fatfreddiescat wrote:

Originally posted by fatfreddiescat fatfreddiescat wrote:

Originally posted by snowflake snowflake wrote:

Originally posted by fatfreddiescat fatfreddiescat wrote:

Originally posted by snowflake snowflake wrote:



I'm not sure what T.D. means about a paralell inductor in that diyaudio thread so maybe there is a completely different way to go about this.

My take on it is that the inductor is pat of the highpass filter, by being directly connected across the driver terminals it effectively shorts the driver out at low frequencies, hence damping any diaphragm movement caused by the other drivers in the waveguide. With a capacitor in series the driver is effectively decoupled from the amp.


so you can make a first order filter like this with just an indcutor in parallel (though even with an L-pad it's going to draw significant power out of passband).

but isn't this also true of all even-order passive filters? - the Le is paralell with the driver will short at low frequencies and damp the tweeter with back-EMF.
Exactly that, though the inductor wouldn't necessarily be directly accross the driver in the case of a 3rd order filter or if followed by an L pad etc. If the driver were to be connected directly to the outputs of an amp then then the amps damping factor will do the job. 

PS would love to come and have a listen to ur sounds when all this lockdown malarkey has passed, we were planning on doing a night in Bristol with my system this year until it turned into a washout.


yes, definitely let me know if you are ever down here. Would be nice to get all the gear out the lockup.

It's strange this unity horn stuff - even though I've managed to build some that seem to work pretty well, I still don't think I understand a lot of what is going on!

been thinking about what Danley says about caps in series and inductors in parallel. Does that imply that if you put a DC blocking cap in series with a driver you reduce the damping factor to almost zero at low frequencies?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote fatfreddiescat Quote  Post ReplyReply Direct Link To This Post Posted: 01 October 2020 at 9:57pm
Originally posted by snowflake snowflake wrote:

Originally posted by fatfreddiescat fatfreddiescat wrote:

Originally posted by fatfreddiescat fatfreddiescat wrote:

Originally posted by snowflake snowflake wrote:

Originally posted by fatfreddiescat fatfreddiescat wrote:

Originally posted by snowflake snowflake wrote:



I'm not sure what T.D. means about a paralell inductor in that diyaudio thread so maybe there is a completely different way to go about this.

My take on it is that the inductor is pat of the highpass filter, by being directly connected across the driver terminals it effectively shorts the driver out at low frequencies, hence damping any diaphragm movement caused by the other drivers in the waveguide. With a capacitor in series the driver is effectively decoupled from the amp.


so you can make a first order filter like this with just an indcutor in parallel (though even with an L-pad it's going to draw significant power out of passband).

but isn't this also true of all even-order passive filters? - the Le is paralell with the driver will short at low frequencies and damp the tweeter with back-EMF.
Exactly that, though the inductor wouldn't necessarily be directly accross the driver in the case of a 3rd order filter or if followed by an L pad etc. If the driver were to be connected directly to the outputs of an amp then then the amps damping factor will do the job. 

PS would love to come and have a listen to ur sounds when all this lockdown malarkey has passed, we were planning on doing a night in Bristol with my system this year until it turned into a washout.


yes, definitely let me know if you are ever down here. Would be nice to get all the gear out the lockup.

It's strange this unity horn stuff - even though I've managed to build some that seem to work pretty well, I still don't think I understand a lot of what is going on!

been thinking about what Danley says about caps in series and inductors in parallel. Does that imply that if you put a DC blocking cap in series with a driver you reduce the damping factor to almost zero at low frequencies?

Yes, a dc blocking cap does just that, as to whether it is a problem or not is another matter, I guess when you have the mids and lows sharing a waveguide, the pressure at low frequencies will be higher so more potential for issues, think Dave Rat came to the same conclusion when he was loosing hf drivers on cabs that were not plugged in but close to others that were.
Do give me a shout when you do have something planned, my brother is in Bristol, used to make visuals for the recursive dome and also my son has another year at uni there.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Elliot Thompson Quote  Post ReplyReply Direct Link To This Post Posted: 01 October 2020 at 11:40pm
Originally posted by citizensc citizensc wrote:

Originally posted by Elliot Thompson Elliot Thompson wrote:

Originally posted by citizensc citizensc wrote:

Its not that I want the one with the most output beyond 10k, Its just that I am a little concerned that the HF1440 will have so little output beyond 10k that it will be impractical to EQ it. I suspect this will not be the case, that's why I am willing to try it. 


I understood exactly what you meant.

Bear in mind for every boost you add in terms of equalisation, increases the power requirement to attain the desired output level, that will sound pleasing to your ears. Both companies offer impedance graphs. So that is one obstacle you've overcome. The next obstacle would be to determine which driver offers the lowest Le figures. Once you get those figures, you will be able to determine which driver will require the least amount of dB boost in terms of EQ to attain the desired high frequency needed which, will sound pleasing to your ears.

Best Regards,


By this do you just mean the simple Le value in mH as published on the B&C website? Or the Klippel model which includes Le2 and Re2? 

I understand that inductance impacts on the HF response of a driver, even in the context of subwoofers (look at the B&C DS series drivers) but this cant be the sole determinant of HF response in a compression driver can it? Not with how many other variables there are? Do we not have to take phase plug geometry, compression ratio, reflectors, diaphragm material, diaphragm geometry among other things in to account as well? 


With regards to passive crossovers, right now my focus is to get the horn to work acoustically and just use DSP (Linea ASC48). Once I have figured that part out, I may attempt to build a passive xover. 



The simple Le value has been the standard for decades and, you should use that for reference when comparing various drivers than Klippel. The reason is, not every manufacture follows the Klippel topology which, can lead to assumptions that may not be correct when comparing various drivers.

 

A compression driver is a loudspeaker so, it is not an exception to Le. There is a co-relation between the Le and the impedance load  at the given frequencies above 10 kHz for high frequency components.

 

The Horn does play a factor on the impedance curve. However, like cone speakers, compression drivers are generally measured in free air. This eliminates any limitation or escalation from the horn deducting/contributing to the compression driver's frequency response. Compression drivers usually offer a very smooth response. However, things will become more jagged when placed in a horn.

 

If the manufacture did not specify a particular horn on the advertised compression driver charts, one should not assume the driver was measured on a horn. It would be best to contact the manufacture to confirm your assumptions.

Best Regards,

Elliot Thompson
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Phil B Quote  Post ReplyReply Direct Link To This Post Posted: 02 October 2020 at 4:24am
Just to go back a bit...

Did you look at the Syntripp when you were thinking of your original plan?

https://www.diyaudio.com/forums/multi-way/264485-syntripp-2-2-virtual-single-source-horn.html

We built a pair for an install here in Melb with B&C drivers about 5 years ago and they perform really well. With more modern Neo drivers they would be very light weight?

There's loads of info in that thread as well..

As you were...

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Post Options Post Options   Thanks (0) Thanks(0)   Quote BigSoundNorthWest Quote  Post ReplyReply Direct Link To This Post Posted: 02 October 2020 at 9:56am
Hello, 
extremely nice to see you back on SP Kyle :)
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Post Options Post Options   Thanks (0) Thanks(0)   Quote citizensc Quote  Post ReplyReply Direct Link To This Post Posted: 03 October 2020 at 10:34am
I have looked at a lot of different projects but not the Syntripp, it looks interesting, I like the idea of being able to separate it in to two parts. It is how ever a different set of compromises to what I am aiming for. I hope for much higher sensitivity and do not need an f3 that low. The other thing is I want this system to be purely 'me'. All my designs, something I can be proud of. While I would like the system to pay for its self at some point, one of the main reasons for the project is to challenge my self. 
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