ulf wrote:

If you have no experience of HornResp I suggest that you download a copy and try it out. It is a very neat software that is useful when designing horn speakers. You can easily make simulations and get a decent result concerning frequenzy response and so on.

Romy the Cat wrote:

I can not speak Swedish and have no idea what they say but here is a Swedish 50Hz horn project. I admit that I have difficulties to like people who design horns in Hornresp but… for whatever it worth…

It is not that I hate the software itself bit I hate any thinking where Hornresp accepted as an evidence or as anything else besides being an abstract and an irrelevant tool.

Hornresp calculates acoustical impedance, frequency response, driver’s impedance, diaphragm displacement, phase response and group delay. Hornresp is in a way familiar with front and back chambers, multi-driver chambers and different horn profiles. It is purely magical software, right? Well, not really as it has absolutely no awareness about sound and therefore Hornresp can predict the result with the same accuracy as observing of whether the earth’s minerals content are capable to predict the taste/smell of wine.

Horns are odd and one of the oddities of horn is in their “extrovertness”.  There are a lot of things are going on in compression drivers, in horns and in many instance the resulting sound is rather a subject of accident rather a rule. Whatever HornResp dose have existed in various spreadsheets where looking at the mouth size and the horn profile it is possible to say easily the cut off of a given horn. It is very simple dependence and there is nothing else to “predict” in there. Then looking at the size of the throat it is possible to say the length of the horn and now the LF will be “loaded”. It is absolutely it – there is nothing else that could be said generically as anything else is strictly the subject of the given implementation.

Why do we need to know a horn’s frequency response if the lower cut off is known from the mouth size and the band-bath response is absolutely not predictable?   Will the Hornresp take under consideration the forth with wish witch the cone mounting scares are tighten, the offset of the drive to the horn axes, the toeing out of the horn the diaphragm  maternal of suspension or the miss-alignment of the diaphragm? Of course not, and I did not mention even 10% of the frequency response shaping criteria. Also, to talks about the “frequency response” in context of bass horn is truly bogus thing to do… if we do the bass horns.

The driver impedance? Did you even try to measure the impedance and compare it with “predicted” impedance? If so then you know the answers… Also, what impedance would say to you  without the relevancy to the actual sound?

The diaphragm displacement? Yes, this is a truly necessary parameter! (It was sarcasm).

The phase response and group delay? … and , what will you do with it?

The front and back chambers? Sure, god luck, the cavity reflections in the chambers are very predictable by software.  (It was sarcasm as well). Also, did you even try to measure the volume of your chambers?

The Multi-driver chambers? Who the hell are going use the multi-driver configuration?

Well, my point is that I feel that the Hornresp is absolutely not necessary took and has absolutely no illustrative purpose of any kind behind being a self-entertaining toy. The Hornresp has some evilness in itself as well.  A person who endowed heavily into Hornresp fate is loosing eventually that vital ability to critically listen the auditable results and to micro-react to the evens of own design progress. I personally feel that the proper methodological recognition and objective assessments of the subjective listening expressions is the very fundamental and very essential qualification of a person who built own playback. Unfortunately the Hornresp does not advance it's use toward this direction and therefore I recognize the Hornresp as a superfluous and wicked tool.

I should not even stress more that I do not like people at DIYAudio.com. The domination majority of them incredible idiots and the brightest among them… do not really have any perspective what audio is all about. I do admit that in some seldom cases they have some seldom interesting posters among them…. but those people do not see subjects in content in context of DIY Audio…

Anyhow, it was pointed out to me that the deaf and senseless Morons from DIYAudio discussed the use of HornResp and mocked my position of rejection the HornResp modeling as a useful tool. I do like when the cretins with understanding of audio at the pathetic level of Fitzmaurice are trying to make opinion about the subjects that they do not understand. Why a blind person does not advise a painter how to draw the world?  Reading the comment of the idiots from DIYAudio (practically on any subject!!!) I always feel that those people are characters from Tchaikovsky’s Iolanta opera. The Iolanta was daughter of a King Rene and she was born blind. Her father made the Iolanta’s family and everyone on his kingdom do not tell Iolanta about her blindness and about the entire idea of light and sight. The very same with DIYAudio morons – they massage the worthless topics (like how to use HornResp) but their efforts have as much relativity of the actuality of Sound as the Iolanta’s thoughts about the colors of roses.

Among, many worthless posts on the subject in the DIYAudio thread I came across a very good one - surprisingly it was by Earl Geddes. Earl is usually at anti-horn position and he typically uses horn disinformation to promote his idea or waves navigation and eventually to sell his products – nothing unexpected. Still in context of the purposefulness of the HornResp the Earl comment was very accurate:

Earl Geddes wrote:

Having done a good deal of horn modeling myself, I will say that there are areas where its easy and areas where its difficult to impossible. Modeling a horns impedance and its load on the driver is the easiest part. Thats because the Horn Equation is basically an impedance equation - it is one dimensional. But the true wave motion is three dimensional and as such any aspect of the horn that requires a good knowledge of the three dimensional aspects will be poorly represented by any model based on the Horn Equations - such as Hornresp. In practice what does this mean? The simulations will be very good for impedance - as shown above - good for the very low frequencies where the wavelengths are much longer than the horn dimensions, but they will likely fail miserably as the wavelength starts to become comparable in size to the actual device. That said, it turns out that virtually all contours act the same when the wavelengths are very large - only minor differences occur in the loading and the response. This is true for just about any contour with the same throat and mouth area and length. The connecting shape just doesn't matter that much. And where the shape does make a bigger difference, the Horn Equation is no longer accurate. Horn design is a tough nut to crack.

The Earl comments were very accurate but not describing the problem in full. There are many-many other aspects of Sound reproduction by horns that could not be modeled. Tone for instance. How the hell anyone is able to observe tonal changes during the horn equalization with a stupid and ignorant software? Tone and quality of tone is a language itself and it has no algorithmable properties. No one knows where Tone comes from in audio. Well, we might know where it comes from but we have in audio very-very difficult time to control tone. There are many y other characteristics that are superbly important (like depth transients EQ, harmonics, compression, distortions with volume, proximity to the “horn choking”, type of the high pass filter, different types of damping  etc…) that are completely not handleable by modeling software. So, what modeling software can actually do? As Earl said – juts to calculate sound pressure – nothing more – good enough for DJ and good enough for the simpletons who are on their brain-hunting journey at DIYAudio site.

Hi Romy,
It seems that the idea of tone is not only lost to most speaker designers but to most electronics engineers as well. When you hear the excrement most designers call an amplifier you would swear that they have never not even once heard a real live instrument or they would KNOW that something isn't right.  Now my biggest problem with tone from horns comes from the "cupped hands" horn effect, which is really nothing more than the resonances fromt he horn itself.  In this area I believe I saw that Geddes has made some real progress; however, I don't think this man can hear well or his speakers are in fact poor because he once confessed to me that a $150 pioneer receiver already delivered sufficiently good sound quality for him. 

Audibility of electronics?? Perish the thought!  He simply was of the mind (and I do mean simpleminded) that since the distortions from electronics were sufficiently low (however he determined this) compared to speakers that they could not possbily have audible consequences.  Nevermind the obvious fact that distortions made by loudspeakers and distortions made by electronics are of two completely different mechanisms and types.  Nevermind that most distortions in loudspeakers are either low order harmonic or intermodulation distortions or NON-harmonic distortions (cone noise, cabinet vibration, horn resonance, crossover energy storage etc.) and electronic distortions are high order harmonic and intermodulation, jitter (or the analog equivalent), noise and RFI etc. so in effect one doesn't readily mask the other.  He fails to realize just how unnatural many electronic distortions are and as such the unnerving effect they can have on listening.

I have heard one horn system that I am quite impressed with though Romy, its the Lansche Audio Goa.  It has a horn midrange and a horn loaded plasma ion tweeter.  Very good sound but still not completely free from all horn effects...but close and very dynamic at 100db/watt.

morricab wrote:

Now my biggest problem with tone from horns comes from the "cupped hands" horn effect, which is really nothing more than the resonances fromt he horn itself.