Hello,
Floyd Toole PhD tells us that the most important variable in determining speaker preference is Frequency Response. After FR come things of lesser importance like phase, harmonic distortion, intermodulation distortion and HOM’s / resonances. We can DSP, equalize and otherwise minimize signature horn sound yet it remains.
Not to say “horns sound bad”, many like even prefer the horn sound. By the time you build it, refine it, and apply DSP to it you gota love. So have at it.
I prefer to keep CD compression distortion and horn acoustic impedance reflections out of my mid-range.
I sometimes use JBL D2 Compression drivers and M2 wave guides with resistors in series and in parallel to help tame the impedance peaks plus DSP equalization. The crossover is above most of the nasty acoustic impedance peaks.
Floyd Toole PhD tells us that the most important variable in determining speaker preference is Frequency Response. After FR come things of lesser importance like phase, harmonic distortion, intermodulation distortion and HOM’s / resonances. We can DSP, equalize and otherwise minimize signature horn sound yet it remains.
Not to say “horns sound bad”, many like even prefer the horn sound. By the time you build it, refine it, and apply DSP to it you gota love. So have at it.
I prefer to keep CD compression distortion and horn acoustic impedance reflections out of my mid-range.
I sometimes use JBL D2 Compression drivers and M2 wave guides with resistors in series and in parallel to help tame the impedance peaks plus DSP equalization. The crossover is above most of the nasty acoustic impedance peaks.
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I agree, I'm just teasing....really though, not all horn/cd combos have these issues is what I think.... I've seen unsmnoothed measurements that did not look like a "saw" though I was not able to see the impedance...I'll be sure to document my experience with the Axi and this elliptical tractrix, that spent +4 weeks in the German mail system, soon as its across the ocean.
You have some people with experience of multiple systems telling you that a proper horn system sounds proper...the signature sound of a horn system? Are you referring to the extremely precise and accurate playback lol?
You have some people with experience of multiple systems telling you that a proper horn system sounds proper...the signature sound of a horn system? Are you referring to the extremely precise and accurate playback lol?
Mine don't, and I have the same to say as Pano. I use DIY OS waveguides, different to you. They are very easy to have sound bad...DualTriode said:
..is best not overinflated by minimising the importance of other things..
I'm struggling a bit to keep up with your discussion on electrical impedance, and whether it relates to acoustical impedance in that way.
I am sure that I am unable to distract from your personal experience.
First, keep in mind that I pointed out “the importance of other things’ to the signature sound characteristics of Compression Drivers and their attached horns/ waveguides. Harmonic distortion, intermodulation distortion and acoustic resonances plus other variables are all are important to the sound of a CD and attached waveguide / horn. No strawman here to minimize.
No need to struggle. Keep in mind that a CD with an attached horn / waveguide is an electro acoustic transformer; it is not solely electrical or acoustic. Remove the horn from the CD and run an impedance sweep of only the CD and you get one version of the impedance plot. Attach any horn that matches the bolt pattern and run a second impedance sweep. That impedance plot will be different than the first plot without a horn attached. If you want to dig deeper change out the horn again on the same driver and you get an entirely different impedance plot. The difference in plots is due to the varying acoustic impedance of the different horns / waveguides. If you are into it attach your OS horn if you like.
Short version the electrical sweep of the CD voice coil is a direct reflection of the acoustic impedance of the attached horn / waveguide. There are in fact distinct measurable differences in acoustic impedance.
Just for grins I have measured many of these CD / horn / waveguide combinations.
Thanks DT
First, keep in mind that I pointed out “the importance of other things’ to the signature sound characteristics of Compression Drivers and their attached horns/ waveguides. Harmonic distortion, intermodulation distortion and acoustic resonances plus other variables are all are important to the sound of a CD and attached waveguide / horn. No strawman here to minimize.
No need to struggle. Keep in mind that a CD with an attached horn / waveguide is an electro acoustic transformer; it is not solely electrical or acoustic. Remove the horn from the CD and run an impedance sweep of only the CD and you get one version of the impedance plot. Attach any horn that matches the bolt pattern and run a second impedance sweep. That impedance plot will be different than the first plot without a horn attached. If you want to dig deeper change out the horn again on the same driver and you get an entirely different impedance plot. The difference in plots is due to the varying acoustic impedance of the different horns / waveguides. If you are into it attach your OS horn if you like.
Short version the electrical sweep of the CD voice coil is a direct reflection of the acoustic impedance of the attached horn / waveguide. There are in fact distinct measurable differences in acoustic impedance.
Just for grins I have measured many of these CD / horn / waveguide combinations.
Thanks DT
The relationship of a cd and horn sound very much like that of a dynamic driver and its enclosure........................................................................................... .......................... .......... ............................................................... ........................................... ..........................................
Can you show an example (measurements) of how good it can be with dynamic radiator, for comparison?
Can you show an example (measurements) of how good it can be with dynamic radiator, for comparison?
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Since it's (old) Biradial diffraction horn with minimum phase resonances (Don Keele) you claim proper EQ does not help and you still hear them?
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Yes much of the Frequency Response can be straightened out (equalized) with a 31 band equalizer or DSP. Yet still many of the signature horn sound characteristics remain; diffraction, harmonic distortion, intermodulation distortion (distortions caused by compression) and frequencies that reflect about inside the horn & are delayed relative to the direct radiated sound that does not bounce around (HOM’s). This horn can and does sound pretty nice but it still is a horn.
Plus if you do a lot of boost to equalize, that also increases the relative level of distortion.
Thanks DT
Plus if you do a lot of boost to equalize, that also increases the relative level of distortion.
Thanks DT
Yes I can do that.
I will be back to the lab and bench next week. Tuesday or so.
Thanks DT
Try smooth throat waveguide.
@RobWells: this is Radial horn with flat front. Diffraction slot early at throat. Some newer has smoother diffraction slot. In ATH thread I've shown comparison between similar to TD250 vs smooth throat.
This seems a lot liking saying, like it or not, solid state amps all sound likes solid state amps. Or tube amps all sound like tube amps. They don't. Such sweeping statements have very little chance of being accurate.
Do all direct radiator speakers sound like direct radiator speakers? What would that mean?
Do all direct radiator speakers sound like direct radiator speakers? What would that mean?
You're not going to vary acoustic impedance messing around at the driver terminals, but you can avoid subsequent issues with your crossover at the electrical level. Maybe that's what you meant?
Also some of these impedance variations are related to the compression driver rear enclosure. Surely nothing directivity related will come of that, nor does it need to be avoided?
I read somewhere that barbarian efforts result in barbarian results.
Proper use of horns and compression drivers result in proper sounding speakers (there are enough of them out there).
Horns are decade devices and usually not suitable for wider band use. A typical decade would be 600-6000 Hz. If we use horns too large for a frequency range, they behave like transmission lines. If the horn is too small for the lower end, we get a terrible honk. Neither of these effects are a "fault" of the horn, rather a sign of the competence of the designer.
In spite of wishful thinking, there are very few exceptions to the decade rule.
One additional issue is that if we have a very efficient driver, the source and amplification warts will be very obvious. Many amplifiers have "warts" at low power (one of the reasons that Nelson Pass has a series of amplifiers called "First Watt").
We have to be careful about "blaming" the horns, although it is convenient considering how many bad designs are out there.
Proper use of horns and compression drivers result in proper sounding speakers (there are enough of them out there).
Horns are decade devices and usually not suitable for wider band use. A typical decade would be 600-6000 Hz. If we use horns too large for a frequency range, they behave like transmission lines. If the horn is too small for the lower end, we get a terrible honk. Neither of these effects are a "fault" of the horn, rather a sign of the competence of the designer.
In spite of wishful thinking, there are very few exceptions to the decade rule.
One additional issue is that if we have a very efficient driver, the source and amplification warts will be very obvious. Many amplifiers have "warts" at low power (one of the reasons that Nelson Pass has a series of amplifiers called "First Watt").
We have to be careful about "blaming" the horns, although it is convenient considering how many bad designs are out there.
Sadly generalizations are usually just wrong.
Saying all of anything is pretty much always incorrect.
Like saying all dome speakers are xxxx. Or all tube amps suck, or all transistor amps.
There are good quality designers out there that can make almost any type of speaker sound quite good. Some types of designs may be harder than others, but certainly not impossible. IMHO.
Saying all of anything is pretty much always incorrect.
Like saying all dome speakers are xxxx. Or all tube amps suck, or all transistor amps.
There are good quality designers out there that can make almost any type of speaker sound quite good. Some types of designs may be harder than others, but certainly not impossible. IMHO.
When I switch the dual woofers in my sub sim from series to parallel the impedance curve changes...but it’s not linear ...I also understand that when I manipulate the curve in this fashion it’s not connected to the acoustical impedance...can you explain why the change in the curve isn’t linear?
Hello All,
Today being Sunday this is not blasphemy or vanity but directly out of the AES doctrine library.
Audio Engineering Society Convention Paper 5641 Presented at the 113th Convention 2002 October 5-8 Los Angeles, California, USA
http://www.nutshellhifi.com/library/Vioshvillo_2002_Horn_Distortion.pdf
From the ABSTRACT,
“Horn drivers have the worst nonlinear distortion compared to other components of professional sound systems (omitting free propagation distortion). Some of the driver’s distortions can be mitigated by proper mechanical measures. However, distortions caused by nonlinear air compression and propagation are inherent to any horn driver.”
Unlike amplifiers where THD+N is measured in parts per million, drivers are measured in parts per hundred or percent.
Thanks DT
Today being Sunday this is not blasphemy or vanity but directly out of the AES doctrine library.
Audio Engineering Society Convention Paper 5641 Presented at the 113th Convention 2002 October 5-8 Los Angeles, California, USA
http://www.nutshellhifi.com/library/Vioshvillo_2002_Horn_Distortion.pdf
From the ABSTRACT,
“Horn drivers have the worst nonlinear distortion compared to other components of professional sound systems (omitting free propagation distortion). Some of the driver’s distortions can be mitigated by proper mechanical measures. However, distortions caused by nonlinear air compression and propagation are inherent to any horn driver.”
Unlike amplifiers where THD+N is measured in parts per million, drivers are measured in parts per hundred or percent.
Thanks DT
So those little squiggly lines...you think thats going to ruin the sound?
OK your friend says
but his colleague says
- Audio Engineering Society Convention Paper 5639 Presented at the 113th Convention 2002 October 5-8 Los Angeles, California, USA
And with this post, I Bid adieu
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