Fwiw, those who are testing and posting based upon "foam" inserts into "horns" ought to specify the foam being used, and the horn being tested, along with the driver?
This makes a difference. It's not all equal.
Someone said that HOMs will rise with level? Sure, but so will normal distortion(s), so that is not a clear indicator.
The fellow who wants to eliminate honk? Get urself a quality horn and a quality driver, the honk will go away. What is quality in those things? You'll have to read some threads, especially the Geddes Waveguide thread(s) and the L'Clerc'h thread(s). If ur using a cheap plastic horn or a cast aluminum horn, they're not likely to perform well without modifications (if at all), fwiw.
Personally, I am still puzzling about these HOMs...
_-_-bear
This makes a difference. It's not all equal.
Someone said that HOMs will rise with level? Sure, but so will normal distortion(s), so that is not a clear indicator.
The fellow who wants to eliminate honk? Get urself a quality horn and a quality driver, the honk will go away. What is quality in those things? You'll have to read some threads, especially the Geddes Waveguide thread(s) and the L'Clerc'h thread(s). If ur using a cheap plastic horn or a cast aluminum horn, they're not likely to perform well without modifications (if at all), fwiw.
Personally, I am still puzzling about these HOMs...
_-_-bear
bear said:
Its not that easy, Geddes says there is a Honk in all CD options accept his own (Including expensive option).
Also the point here is to figure out what will eliminate the honk.....Atleast that should be the simplistic goal and for now the only audible goal since we can not really measure HOM let alone know what the "HOM" sounds like.
Besides this isnt the only thread about this issue, its the 3rd thread......and there are other sites with lots of discussion, testing about to happen so we shall see. My $$$ is still on the sub $10 waveguide options on the net vs Geddes's $400 choice
doug20 said:
Dr. Geddes is entitled to his opinions.
His technical abilities are clearly superior.
That may or may not translate into superior results.
I have yet to have an opportunity to hear one of his waveguides, but would welcome that chance.
HOM sounds like nothing until you first have a quality horn based speaker system and a quality electronic system to back that up. Not a trivial matter. I'd suggest that HOM is probably a higher order concern when putting together a system... perhaps like tweaking that xover Q...?
The $400 choice is inexpensive in the world of audio. You can build your own for far less. Why not try, if you are strapped for bux?
The old saying that you "get nothing for nothing" or "you get what you pay for" probably applies to a great extent here. While you can get good results on the cheap IF you apply knowledge to the problem and buy used (like drivers, for example) or build your own (horns, for example) you are only substituting labor/time for $$...
As I said before if ur using small plastic commercial horns, you'll probably get results commensurate with what that is...
Maybe if you posted your "honk" producing horn in a new thread people could comment on it - or if you wanted "non-honk" horns you could post asking for suggestions and discuss that topic. This is about the somewhat new and elusive HOM issue, not honk?
_-_-bear
bear said:
I disagree, there are EXCELLENT inexpensive off the shelf plastic or cast solutions that need no modification. IE the 18 Sound horn.
18 Sound Constant Coverage Horn
An externally hosted image should be here but it was not working when we last tested it.
I have around 25 pairs of treble horns here (commercial and home made), these sound the best for hifi IMHO.
doug20 said:
Its not that easy, Geddes says there is a Honk in all CD options accept his own (Including expensive option).
Also the point here is to figure out what will eliminate the honk.....Atleast that should be the simplistic goal and for now the only audible goal since we can not really measure HOM let alone know what the "HOM" sounds like.
Besides this isnt the only thread about this issue, its the 3rd thread......and there are other sites with lots of discussion, testing about to happen so we shall see. My $$$ is still on the sub $10 waveguide options on the net vs Geddes's $400 choice
The 10 dollar Parts Express conical horns don't sound so great. The Geddes horns should be superior in a very tangible way.
bear said:
I disagree also, of course. For $208 total, waveguides, drivers, and crossovers, anyone can find out. It does not honk.
I believe, conceptually, there is a relationship between honk and HOM. According to Jack Bouska's analysis, honk is coming from mouth reflection back down the throat, reflected internally, and out again. That's major HOM by one view, and attention to mouth termination, as Geddes also recommends, can go a long way toward mitigating it:
http://www.audioheritage.org/vbulletin/showthread.php?t=12967
TrueSound said:
Thats the 1086 right?
It has had lots of great reviews and good measurements, the only negative I read about it was that its throat had minor diffraction issues.
Did you compare the XT-1086 vs the DDS eng 90??
I do like how the 1086 looks.
TrueSound said:
TrueSound said:
That isnt the $10 option Im talking about but to say it doesnt sound great seems a little subjective. Is that unmodified? meaning it still had the screw on throat and no material was added around it to reinforce it?
Emerald Physics have had a great following with their CS-2 and now their CS-1s, the CS-2s used the 12" PE waveguide.
Also, isnt the 12" PE conical waveguide same as the MCM 12" WG? PaulW from HTGuide did some measurmenets of it vs the DDS eng 90 and the results showed that it held its own from what I undestood.
ZilchLab said:
Right. And that's what got me started on the whole "soft lips" kick. See this thread.
Horn Honk and Towels
Jean Michel Le Cléac'h has a different approach, and that is rounding over the mouth (continuing the curve) right back around. Thus the wave doesn't reflect back into the throat, or toward the listener.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=140190
Hey Guys,
Long time Lurker but first post.
Has anyone seen Dave Gunness stuff "Gunness Focus"
Here's a link to two papers you might find interesting
http://fulcrum-acoustic.com/wordpre...y-for-loudspeaker-transient-response-2005.pdf
http://www.eaw.com/info/EAW/Technical_Papers/NT_Whitepaper.pdf
The software used to produce the charts is FChart an EAW proprietary Modelling Measurement system. (they're actually in color - doesn't show well in the papers)
cheers,
ferrit37
Long time Lurker but first post.
Has anyone seen Dave Gunness stuff "Gunness Focus"
Here's a link to two papers you might find interesting
http://fulcrum-acoustic.com/wordpre...y-for-loudspeaker-transient-response-2005.pdf
http://www.eaw.com/info/EAW/Technical_Papers/NT_Whitepaper.pdf
The software used to produce the charts is FChart an EAW proprietary Modelling Measurement system. (they're actually in color - doesn't show well in the papers)
cheers,
ferrit37
- My apologies / I certainly was remiss in my house-keeping duties ( nothing new there
)(a) There are no foam inserts included in my measurements.
- Presently my "foaming interest" is focussed on the termination of the horn bell .
- I've been ( casually ) looking for the diffraction artifacts caused by the sudden bell termination . So my pics will have, foam or "no=foam" notations .
- The "foam" reference that you noticed was referring to some 1.75" pipe-foam ( that was then sliced down the middle ). This length was then added to the leading edge of the metal horn bell ( effectively giving the bell a 1/2 circle roll-over ).
(b) Horn ?
- Emilar EH-500-2 Radial
- plus Selenium 1.4" to 2" throat adapter
(c) Driver ?
- Altec 288-8K
>< cheers
TrueSound said:
I appologize for this as I was unaware of this thread and do not recall a request from you.
I have not had and will not have time to read this thread in its entirity, and this topic is discussed elsewhere. But let me repeat the important aspects.
HOM do exist that has been proven (See Makarski in AES for example). They were developed theoretically from waveguide theory, and they cannot exist in horn theory. Bottom line here is that they exist is irrefutable.
Are they audible? Thats another issue. There is no proof that they are, but there is a lot of circumstantial evidence that they are. What is this evidence? The more that you reduce them the better the waveguide sounds. But this is confounded data, because several things are changing when HOM rae reduced, the most significant being reflections. But contrary to what many believe reflections are NOT HOM. They are related, but they are not the same thing. Thats because reflections can be HOM and not-HOM and it is hard to sort out which is which.
Can they be measured? That too is very difficult as a review of the Makarski paper will show. His technique is beyond most DIY capability. There is a paper on my website which shows some data in this regard, but it is not conclusive. There are some ideas as to a simple way to measure them, but none of them has been proven out.
That reducing the HOM in a waveguide design results in a dramatic improvement in sound quality is fairly well recognized at this point. Everyone appears to be doing things that in their horns that will reduce the HOM and there is a good reason for this. To what extent the improved sound quality is a direct result of the lower HOM is unclear. THAT better waveguides with lower diffraction (HOM) sound better than horns with large amounts of diffraction is, IMO, incontestable. Time will tell what is what, but its clear that there is something to the HOM situation.
Googling HOM will always come up with my name simply because I was the first person to identify their existance, at least theoretically. They had been hypothesized to exist before, but never shown how and when they would exist and most importantly how to design a device that minimizes them. That is clearly my contribution.
Hello,
I think the best way to plot a spectrogram is with time axis shown in periods, not 'real' time as in these papers. This is the case when the end user is a human. Human is a logarithmic 'device' and thus perceived phenomenas don't follow linear time-frequency scale.
- Elias
I think the best way to plot a spectrogram is with time axis shown in periods, not 'real' time as in these papers. This is the case when the end user is a human. Human is a logarithmic 'device' and thus perceived phenomenas don't follow linear time-frequency scale.
- Elias
Ferrit37 said:
Salas said:
- I found your initial comment to be "leading" .
- I assumed at the time that you were referring to Neutrino Detection .
- Here in Canada, we have the Sudbury Neutrino Observatory dedicated to the difficult task of detecting these sub-atomic particles .
HOMs
- As it turns out , your comment was quite prescient .
HORN-HONK
- Since the subject of "Horn Honk" was raised quite early in the thread, I think it appropriate to help move the conversation in that general direction / since identifying ( & eliminating ) its' causes look like "baby-steps" when compared to detecting ( & reducing ) HOMs ( assuming the DIY approach ) .
- Based on some of the more recent contributions to this thread , I see that some others might agree with that position .
>< cheers
Indeed. From what I gather from the thread up to now, I guess that designing against the experimentally elusive HOMs surely makes a WG better in many aspects. But how the industry or the advanced DIY will have a scale of success towards a goal without a concrete way of measure? Its kind of sarcastic that the mathematically objective HOM can be presently quantified mostly subjectively for its presence or attenuation.
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