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jason str

Jubilee, Klipschorn, LaScala horn loaded bass bins.

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doesn't solid hard wood crack and fissure even if it is cured?

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On 1/27/2017 at 2:38 PM, jason str said:

Chris, i was pondering over what you have said throughout the thread and think it may just be the combination of the narrow polar coverage due to the wide separation of the horn itself and less folds throughout. Seems both would make a difference in the end result.

The widely separated mouths of the Khorn and Jubilee horn-loaded bass bins leads to polar lobing in the upper registers of the bass bins.  As mentioned, the Belle bass bin has issues when ~500 Hz is reached (which is also in the crossover interference band between the midrange and bass bin--thus masking polar lobing effects from ~400 Hz and higher). 

 

You're right about the effects of narrow polars, i.e., there is experimental evidence from Toole, et al. that  corresponds to lower listener satisfaction in loudspeakers that have narrower effective coverage angles. This is a psychoacoustics issue that Geddes has addressed in terms of loudspeaker directivity requirements:

 

Quote

Summary of Requirements (see page 7).

 

...Above about 500 Hz, the speaker system must posses a narrow, 90° or less, coverage pattern which must be constant with angle and frequency. Stated in another way, the Directivity Index (DI) should be above 9 dB above about 500 Hz and must be flat with frequency.

 

...The polar pattern below 500 Hz...the DI can fall to about 3 dB below 500 Hz. [Note: that I've found that directivity below 500 Hz significantly contributes to speech intelligibility, clarity of presentation, and overall loudspeaker timbre neutrality...CLA]

 

...[Loudspeakers] should be oriented in the room in such a way as to avoid reflections off of the walls closest to them...Good loudspeaker design is always a benefit, regardless of the room, but good room design and source placement and orientation makes the difference between a good and a really great sounding system...the loudspeaker system design and its room placement must be such as to minimize diffraction from the cabinet as well as nearby obstacles. Narrow directivity is a significant aid in this regard [i.e., frequency-dependent above the interaural time delay frequency of about 500 Hz...CLA].

 

 

Abrupt horn folds relate to higher order mode (HOM) creation and other harmonic and intermodulation distortion creation within the horn-driver assembly.  If the bends in the horn are smooth and of the same radius (i.e., the differences in depth of the bends in the bend direction are minimized), then the effects of the horn bends are essentially limited to low-pass filtering of the input driver acoustic power/SPL.

 

The real question is...where are the threshold levels that are audible for distortion creation for folded horns?  That threshold isn't zero.

 

Chris

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Guess it won't hurt to create a link to one of the articles i have gone over many times >click here<

 

Here are the points in the article that really intrigue me.

 


At high frequencies/short wavelengths where the bend is an obstacle you don't want to 'bounce' 

shorter wavelengths off reflectors, as your illustration shows. This is what Huygens postulated, 

and he was wrong. If you imagine the wavefront as a group of particles across the width of 

the pathway, rather than one particle as you show it, what happens after they bounce off a 

reflector is that they lose their cohesiveness as a wavefront, emerging at various angles of 

phase and cancelling each other out, killing HF response. 

 

All bends act as series inductors, the tighter the bend the more the inductance, the more bends the more the inductance. You can minimize the effect by keeping the inner and outer runs as close as possible, but you can't eliminate it while keeping the cabinet size manageable.






























 







































 

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For some reason the font, spacing and page size would not cooperate with me on the last post.

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Here is the text that you quoted:

 

Quote

At high frequencies/short wavelengths where the bend is an obstacle you don't want to 'bounce' shorter wavelengths off reflectors, as your illustration shows. This is what Huygens postulated, and he was wrong. If you imagine the wavefront as a group of particles across the width of the pathway, rather than one particle as you show it, what happens after they bounce off a reflector is that they lose their cohesiveness as a wavefront, emerging at various angles of phase and cancelling each other out, killing HF response.

 

All bends act as series inductors, the tighter the bend the more the inductance, the more bends the more the inductance. You can minimize the effect by keeping the inner and outer runs as close as possible, but you can't eliminate it while keeping the cabinet size manageable.

 

Again, the reason why I talked about impedance bounces at discontinuities is due to the reflection of acoustic energy back to the driver--which creates problems.  If you were in essentially free space (in terms of the number of wavelengths to the source of sound) and you put a reflective surface up, then Huygens principle works.  This technique is used in all performance halls to redirect energy back to the audience, down from the ceiling, and in from the side walls. 

 

To say that Huygens isn't right is actually not correct--what the downside is to placing reflectors inside of horns is their effect in reflecting back to the driver(s) within the near-field inside a horn (i.e., less than a couple of wavelengths of travel), as well as generation of higher order modes--something that Huygens wasn't talking about and perhaps wasn't aware of. 

 

All bends in horns attenuate high frequencies.  The question is: how much?  If you don't need high frequencies, then the bends don't have much effect on the desired FR power output if the bends are smooth and large radiused.

 

Two kHz is way too high in single-driver subwoofer horns due to something else: FM distortion (and to an equal degree AM distortion byproducts on top of the FM distortion sidebands).  You can get around that using multiple drivers and multiple entries (ports)--like in a Danley-style MEH.

 

Chris

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I guess I'll offer another contrarian opinion and say I've never heard any folded horn operating into the midrange sound high fidelity or transparent. Just an opinion and based off recordings I've made of acoustic classical and jazz. Even a low efficiency direct radiator (far from my preference) sounds more like what me and my friends heard live than the folded horns. The best of them being the ATC woofer/dome mid combination. Which is why I have been pretty intrigued by seti's midbass horn and the one @Bjorn was working on, but he hasn't updated that thread in a while.

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17 hours ago, seti said:

 

They are good guys to deal with and I trust their ears. I've heard their systems and they are beautiful. I'm going to New York this year to hear their new stuff and Wheel Fi.. Dave Slagle just posted many different new options for autoformers today. Check it out http://www.intactaudio.com/atten.html

 

 

 

I follow his blog as well. I don't need a volume pot/AVC/TVC these days as I do it digitally. He is on my list of guys if I ever need a bandwidth limited OPT.

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1 hour ago, jazzmessengers said:

I guess I'll offer another contrarian opinion and say I've never heard any folded horn operating into the midrange sound high fidelity or transparent. Just an opinion and based off recordings I've made of acoustic classical and jazz...

Have you heard something like this?

 

http://inlowsound.weebly.com/spiral-bass-horn.html

http://www.hometheatershack.com/forums/ported-subwoofer-build-projects/85634-my-lab-12-bass-horn-project.html

 

Or something like these?

 

http://www.danleysoundlabs.com/products/loud-speakers/synergy-horn/sh-96/

http://www.danleysoundlabs.com/products/loud-speakers/synergy-horn/sh50/

 

Chris

 

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5 hours ago, Chris A said:

 

I've heard the SH50 and they were speakers I was considering at one point. Very dynamic speakers, but I couldn't shake the feeling that I was aware that I was listening to horns. I'm not good at describing it since it wasn't like the coloration you hear from those audiophile horn speakers with round horns stacked on top of each that beam at their upper passbands.

 

I haven't heard any of John Inlow's designs either, but would love to.

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11 hours ago, jazzmessengers said:

 

I've heard the SH50 and they were speakers I was considering at one point. Very dynamic speakers, but I couldn't shake the feeling that I was aware that I was listening to horns. I'm not good at describing it since it wasn't like the coloration you hear from those audiophile horn speakers with round horns stacked on top of each that beam at their upper passbands.

 

I haven't heard any of John Inlow's designs either, but would love to.

 

I'm afraid if you don't like horns you're in the wrong forum.

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2 hours ago, jason str said:

 

I'm afraid if you don't like horns you're in the wrong forum.

 

I like horns that are neutral. From everything I've read this is the K-402, and if past experiences are any indication well designed controlled controlled/constant directivity horns have little to no sound of their own.

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14 hours ago, jazzmessengers said:

I've heard the SH50 and they were speakers I was considering at one point. Very dynamic speakers, but I couldn't shake the feeling that I was aware that I was listening to horns. I'm not good at describing it since it wasn't like the coloration you hear from those audiophile horn speakers with round horns stacked on top of each that beam at their upper passbands.

 

Most people have been listening to multiway cone-type loudspeakers all their lives that have irregular polar coverage vs. frequency and in particular irregular coverage angles in their interference bands.  Perhaps your ears were greeted by nearly constant coverage all the way up and down to about 150 Hz in the audible frequency band--for the first time.  The midbass is where the biggest differences would be audible.  Well done straight-sided horns really don't have a "horn sound".

 

Many people have gotten used to hearing loudspeakers that paint the walls, ceiling and floor with early near field reflections at various places in the audible spectrum.  The SH-50s probably didn't that when you heard them and should have sounded very neutral if they were set up well in-room. 

 

The SH-50s also only cover 50 degrees horizontally which is pretty narrow: you'd really need two SH-50s on each side to match stereo K-402 performance.

 

Chris

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2 hours ago, jazzmessengers said:

 

I like horns that are neutral. From everything I've read this is the K-402, and if past experiences are any indication well designed controlled controlled/constant directivity horns have little to no sound of their own.

 

The K-402 horn lens is a good one but like everything else has some drawbacks, lets save that discussion for another thread that is not about bass bins.

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See this thread:

 

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On 1/30/2017 at 9:55 AM, Chris A said:

 

Most people have been listening to multiway cone-type loudspeakers all their lives that have irregular polar coverage vs. frequency and in particular irregular coverage angles in their interference bands.  Perhaps your ears were greeted by nearly constant coverage all the way up and down to about 150 Hz in the audible frequency band--for the first time.  The midbass is where the biggest differences would be audible.  Well done straight-sided horns really don't have a "horn sound".

 

Many people have gotten used to hearing loudspeakers that paint the walls, ceiling and floor with early near field reflections at various places in the audible spectrum.  The SH-50s probably didn't that when you heard them and should have sounded very neutral if they were set up well in-room. 

 

The SH-50s also only cover 50 degrees horizontally which is pretty narrow: you'd really need two SH-50s on each side to match stereo K-402 performance.

 

Chris

 

Before you fall for Danley, you have to drink his cool aid.............that a point source (everything coming from one spot) is the best way to listen to sound.  I agree that seems proper for spoken word but for live music the cool aid hasn't worked on me yet.

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So you choose now to answer this question?

 

 

4 minutes ago, mark1101 said:

I agree that seems proper for spoken word but for live music the cool aid hasn't worked on me yet.

So I assume that you and JC went to listen?

 

Chris

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Nope not yet.  I have only heard Danleys in a church for the moment.  I do intend to visit though.  Only a few miles from me.

 

Actually, I have heard them in Sanford Stadium as well.  (UGA football stadium).

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One of the interesting things that I found this AM is that the recordings that you listen to have the greatest bearing on individual opinions in hi-fi.  I just updated my foobar convolver plugin with the latest impulse response of the Jubs (min phase) captured by REW. 

 

It could be the placebo effect but I feel a greater sense of involvement while the convolver is on with the solo piano recordings that I'm currently playing (Angela Hewitt Plays Bach, disc 1), and which have apparently had very little "mastering".  This recording has attenuating EQ below 450 Hz down (ramping down at about -3 dB/octave), and some amount of compression used (DR rating of "12" instead of a more typical 14-20 for live recorded piano-close miked). 

 

If you're listening to heavily mastered recordings then the microphone-captured phase relationships and even the frequency response of the original music captured by the microphones have been severely compromised, permanently, by the mastering tools used.  Once severely compromised like this, the recordings can never sound truly hi-fi.  It's just another way of saying that you can't hear how good your setup really is while playing bad recordings--only good ones.  If you simply play a really good recording on the setup (assuming it's a fairly capable setup), it's like night and day in terms of the listening experience and perceived fidelity.  I've found that this includes bass bin performance...most strongly.

 

[BTW Mark, I've mentioned before that I've acquired and demastered a couple of Grateful Dead albums...just for you.  I can place these FLAC files on Google Drive for your personal download and listening pleasure since I am certain that you already own these two albums--American Beauty and Live/Dead. Just let me know, and I'll place them there--all I need is your google gmail address to access you.]

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Hey, that's nice of you.  Set me up for download and I'll give it a try.  Of course I do have those albums.  PM sent.

 

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On 1/30/2017 at 9:55 AM, Chris A said:

 

Most people have been listening to multiway cone-type loudspeakers all their lives that have irregular polar coverage vs. frequency and in particular irregular coverage angles in their interference bands.  Perhaps your ears were greeted by nearly constant coverage all the way up and down to about 150 Hz in the audible frequency band--for the first time.  The midbass is where the biggest differences would be audible.  Well done straight-sided horns really don't have a "horn sound".

 

Many people have gotten used to hearing loudspeakers that paint the walls, ceiling and floor with early near field reflections at various places in the audible spectrum.  The SH-50s probably didn't that when you heard them and should have sounded very neutral if they were set up well in-room. 

 

The SH-50s also only cover 50 degrees horizontally which is pretty narrow: you'd really need two SH-50s on each side to match stereo K-402 performance.

 

Chris

 

I have Geddes Nathans in my HT, so I've been living with constant directivity speakers for a while. They do not exhibit the coloration I heard on the SH50. Again I should stress that it wasn't egregious, but just "present".

 

I have the MFSL SACD of American Beauty, the mastering engineer said basically nothing had to be done to it in the transfer from tape. Let me know if anyone wants to hear one track off it (from the redbook CD layer).

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