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10-21-2010 Post does not mapped to Knowledge Tree
noviygera


Chicago, IL
Posts 137
Joined on 06-12-2009

Post #: 1
Post ID: 14761
Reply to: 14761
Midbass impedance bumps -- why and what to do?
fiogf49gjkf0d
I though this would be answered elsewhere (AA) but Bruce Edgar did not reply. This question is important for me, maybe someone can help.

When running an impedance sweep on the Edgar 80Hz horn some serious bumps showed up. (I ran the sweep because it sounded wrong so I decided to investigate)
Also, I have to run a high pass at 160Hz with 6db slope to even out the mid bass!!!

Now the problem that I have with sound is:
1. too boomy and tubby, just plain muddy sounding when simply crossed over at 80 and 350hz
2. box panels, horn flare, rear chamber all resonate. The freq are about 190, 210 hz, and its noticeable by placing hand on different parts of speaker. I wish she was a hot girl, but it's only an audio speaker.

What to do? Here are two imp. sweeps, and maybe something can be deduced.

1st imp. sweep. -- no changes to horn.

Edgar 80Hz horn_factory_imp_sweep.JPG

2nd impedance sweep below. Here I added some wood blocks to the REAR CHAMBER. Notice the Fs went up by 10hz. Curve looks a little smoother.

Edgar 80Hz horn_small_back_chamb_imp_sweep.JPG



Now my question is:

What do I learn from this experiment?
Should the rear chamber be made even smaller? Than Fs will go up more.
But should my goal be to even out the curve at the expense of low Fs?

I do not mind to have a higher Fs for this horn, by the way.

Thank you,
Herman
10-21-2010 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,486
Joined on 05-28-2004

Post #: 2
Post ID: 14762
Reply to: 14761
The Hoi Polloi horn.
fiogf49gjkf0d

Herman,

What you describe is fine. Over the course of last years I had a number of people who report identical things to what you do. Even if you change volume of back chamber and move resonance frequency then sound will change but it most likely will not produce proper sound. BTW, I would pay your attention that you did not mention what driver your horn use and how sound change when you move Fs 10Hz up.

Considering the amount of homework you did and own thoughts you put into asking this question I will collaborate on it but be advised that the subject you post is incorrect as what you complain has nothing to do with resonance frequency. In my view the Bruce Edgar’s midbass horn is wrongly built and designed, at least in the version that you have.

First thing first: Bruce Edgar is the most prominent and the most knowledgeable horn designer and builder alive today, in fact he has been holding this title in my view during many-many years. In addition he does hear the things very well, has cultural and cognitive capacity to interpret properly what he hears - a very seldom quality among individuals who are trying to make acoustic systems. Furthermore, I consider Bruce as my friend, consult with him sometimes and even during my midbass project we spoke a few times and we collaborated on some issues that I had. So, it would be greatly inappropriate for me to criticize the Bruce’s 80Hz horn.

However, one of the keystones of this site is honesty and respect to the actual sonic results. From this perspective I do not feel that criticizing Bruce’s 80Hz horn I violate anything. If Bruce’s, your, mine and anybody else objective to advance horn sound instead of patronizing horn people then  criticizing Bruce’s 80Hz horn will be a great respectful service to what Bruce taught all of us for years.

I do not like Bruce’s 80Hz horn. I heard it only once, I did not like it then but I even more do not like the design idea. 8-10 year back Bruce furnished his Titans with curved 80Hz horn, even that curved 80Hz horn had some problem it in my view was much more interestingly sounding horn. Then Bruce desired to bless the Morons with a straight horn – I think it was a disastrous move: the horn is too short with too large throat, and at least with drivers the Bruce use they shall sound in the way how you descrive.

The need to note that I used the word “Morons” in the last sentence very deliberately. There is Bruce and there are his customers. It was my vocal and persistent position over the years that Bruce Edgar’s customers in dominating majority are incredible idiots. Since I entered the horn field in 1999 I was dealing with them many times and I can testify that 95% of them are remarkable retards. I can publicize many events when I and the some “specific” Edgarhorns owners where involved and it will be absolutely self-evident how much Morons they are, the last even was 3 months back with a retard posted at AA under a moniker “Dan_ed”. The problem however is not only that I know it but that Bruce Edgar intelligent to know it as well. So, what Bruce doe it mitigate the design and implementation efforts in accordance with the level personal stupidity and sonic ignorance of his customers. I would do the very same in I were “in business”. So the short 80Hz straight horn was sort of Bruce’s Hoi Polloi horn for the Morons out there, sort of Bruce’s Volkswagen horn (I original meaning of Volkswagen).

So, I do think that you will be able to fix anything in the Edgar 80Hz straight horn. You can change driver, move Fs up and down, beef the enclosure with sand but it will be all half ass solutions.  I personally did not play with this horn but in my view, looking at the short straight horn with huge throat I do not see a horn but rather I see a direct radiator shooting through a pipe. Many Edgarhorn users do “upgrade” of their Edgarhorn replacing the old curved Bruce’s horn to the new straight one, so you might pick up the old one that will be much better. Alternatively fine some kind of idiots who would buy this appendix horn and ask Bruce to make to you a properly horn if you will be able to accommodate it in your system. (I personally believe that you will not as I feel that 80Hz horn is too large to be located under MF channel).  However, talking with Bruce you need to specify very precisely what you want. Bruce is not a fool and he very much sees what people are trying to accomplish and he will be able to support any level of your demands. However you need to truly have the evolve demands and very precisely nailed down the requirements for your project in order to make Bruce to do what you want. You need to understand that Bruce is accustom to deal with his typical customers – the fucking audio retards that will swallow anything as long it was chip and “recommended”.

Sorry, my reply was not in the direction you would like it to be. If you would like to play with Fs, then set it to 80Hz and it shall be fine, most likely Bruce has do it already. Decrease loading of your tube if you use tube amplification for this channel. More idle tube will lose gain n power but will give you more control over the diaphragm.

Rgs, The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
10-21-2010 Post does not mapped to Knowledge Tree
el`Ol
Posts 225
Joined on 10-13-2007

Post #: 3
Post ID: 14763
Reply to: 14761
Altec 416 sealed
fiogf49gjkf0d
I wonder whether an Altec 416 in a sealed enclosure plus transconductance amplifier would be the better solution for most people/circumstances.
10-21-2010 Post does not mapped to Knowledge Tree
noviygera


Chicago, IL
Posts 137
Joined on 06-12-2009

Post #: 4
Post ID: 14765
Reply to: 14761
Relevant infomation to exploring new options
fiogf49gjkf0d
Romy,

thank you for sharing thoughts on the 80Hz horn, giving honest opinion.  So if the 80Hz horns are flawed design, I do not want to waste time to improve them. By the way, they are loaded with EVM15B drivers.

I am now a bit perplexed on which route I should take and now I need to reformulate my plans. To start with a blank page, as if I did not have them at all, I can explain what I want and what I have already. I am quite happy with the mid and upper sections of my speaker. That can be left alone but what to do on the bottom?

My mid/upper horns play down to 190Hz. That is -- 188Hz is the Fs of the mid. It's a horn loaded a 10" Precision Device driver. So I need a section (or two sections) to cover the bottom (below 190hz).

What can I do here?
1. direct radiator (or multiples) in sealed box
2. "properly" made rectangular horn to play down to about 100Hz with as few compromises as possible + sealed subs below 100Hz
3. something like the Imperial horn sub:  http://www.decware.com/ImperialSO.htm
4. Fostex FW800HS 31.5" Super-Bass System, like here:  http://www.kcsloudspeakers.com/

The problem is that I've only heard my own Edgar horns. I have NOT heard the other options I listed above.
I know what I want to get in terms of sound -- It is the range below 200Hz produced properly:
It must be, detailed texturally, effortless and quick. It must sound dynamically similar at low and high levels. It must NOT be boomy or bloated sounding.
It must have a natural tone that does not stand out as specifically "clean" or "tubby"
What options or configurations should I consider to meet the above goals?

Herman
10-22-2010 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,486
Joined on 05-28-2004

Post #: 5
Post ID: 14769
Reply to: 14765
Options...Options...Options...
fiogf49gjkf0d

 noviygera wrote:
My mid/upper horns play down to 190Hz. That is -- 188Hz is the Fs of the mid. It's a horn loaded a 10" Precision Device driver. So I need a section (or two sections) to cover the bottom (below 190hz).

Herman, if you use Precision Devices hen you are at mid-high 90 sensitively, I am right?

 noviygera wrote:
1. direct radiator (or multiples) in sealed box

It might be problematic with one channel as a crossover point is too high for a single god bass driver to handle it.  If you have very small room then you might experiment with an array of driver like Altec 515B or 515E. The are basso the same driver but with different magnets type. They have around 30Hz resonance and have good tone under 200Hz. The key in using them do not let them to exert too much so you need to have ether a very small room or very many drivers – then become costly nowadays. Otherwise I would do with two channels separate bass chanals.


 noviygera wrote:
2. "properly" made rectangular horn to play down to about 100Hz with as few compromises as possible + sealed subs below 100Hz

This would work as well. If you do rectangular then you might get 80-100Hz under your MF channel. Measure the clearance between your MF and floor and you will see how much space you have. If you go for 80Hz horn and chose parabolic profile then the problem of yours will not be the size of mouth but the length of horn. to make the horn more less EQ bass properly you would need to make the throat relatively small the will make the horn too long. Since the channels need to be time-aligned with MF it might be a true ugly looking configuration. Why don’t you think Bruce went for large-throat and short horn – to make it look acceptable. So, you would need to find a compromise between all parameters of the horn to make it to work propel and to look good in context of your frame. This might be a bit tricky and with all apparent simplicity of the task very few people managed to make this arrangement interesting.

 noviygera wrote:
3. something like the Imperial horn sub:  http://www.decware.com/ImperialSO.htm

I don’t really understand what they are proposing to do.

 noviygera wrote:
4. Fostex FW800HS 31.5" Super-Bass System, like here:  http://www.kcsloudspeakers.com/

I never heard this woofer but can presume that it will not be so great at 200Hz

 noviygera wrote:
The problem is that I've only heard my own Edgar horns. I have NOT heard the other options I listed above. I know what I want to get in terms of sound -- It is the range below 200Hz produced properly: It must be, detailed texturally, effortless and quick. It must sound dynamically similar at low and high levels. It must NOT be boomy or bloated sounding. It must have a natural tone that does not stand out as specifically "clean" or "tubby" What options or configurations should I consider to meet the above goals?

noviygera, I do not suggest what to do. I know many audio people (the Morons) are pissed on me because I do not make imperative comments and do not stick their noses in specific directions. Frankly I do not relay enjoy it and I have no idea what kind satisfaction people experience if they made others to buy something or to build something. Building playback is not a proving of algebra theorem – there are many dimension and the results are not always definitive. There are no definitive answers to your questions. You might take your Elgar 80hz horn, add to it 2-3 feet of extension on the back, change the driver and to get a very good result. The possibility is endless and whatever you do it will be painful, I promise. So, if you have time, interest and some money (it all doe not cost a lot in fact) then begin to experiment. The point is: no one will teach you, show you or help you. The only valuable things that you will gain in your understand and experience you will discover yourself, from your own practice and from your own listening. Sorry, for being not too helpful.

Rgs, Romy the Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
10-25-2010 Post does not mapped to Knowledge Tree
noviygera


Chicago, IL
Posts 137
Joined on 06-12-2009

Post #: 6
Post ID: 14786
Reply to: 14761
Useful findings.
fiogf49gjkf0d
Romy,

Thank you again for a helpful reply. Your comments are very appreciated inspite of not suggesting what to do. I will figure that out myself. And here is what I've learned so far:

>> Herman, if you use Precision Devices hen you are at mid-high 90 sensitively, I am right?

Actually the driver is, I believe, a custom made 10" mid by PD (looking at the magnet and model markings) for Funktion One. It has almost no excursion, maybe 0.5 mm, paper cone, Fs of about 180Hz, 109db sensitivity (in the horn), 12 Ohms. Very fine sounding horns.

Back to the Edgar midbass. I did talk to Bruce Edgar per your suggestion. First off, he is a good person to talk to, I believe very honest and trustworthy. I'd like to thank him and express my respect. He talked to me for about one and a half hours.

1st problem:
the amp I was using. Per B.Edgar's recommendation I changed from Spectron digital amp to Dynaco St-70 to power the 80Hz horns. Much better sound, at least much more tolerable to listen to for longer than one minute. I will continue to analyze the sound I am hearing, but with the Dynaco, the 80Hz horns may be actually useable and worth experimenting to improve the box structure. I cannot believe how much the sound changed in a good direction. I would NOT say it is no longer muddy sounding, but at least it does not pierce the ears like it used to!

2nd problem:
Inheritant design compromise (size). It may be possible to extend the flare and increase the mouth size. Also, this can be solved by using a different, properly shaped/sized midbass horn.

3rd problem:
Enclosure resonances. The problem is in the horn flare being excited near the mouth area. It is definitely an issue. I thought it was originating in the back chamber but it is not. I removed the chamber, ran a sweep test and the impedance bumps were still there, just moved lower.

Question, Romy:
Why do you suggest to add the extension on the back, not the front, as B. Edgar suggested. He specifically commented that the MOUTH area is too small and said the throat size was OK?

Thank you,
Herman
10-25-2010 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,486
Joined on 05-28-2004

Post #: 7
Post ID: 14787
Reply to: 14786
The horns are like a Toilet?
fiogf49gjkf0d
 noviygera wrote:
Question, Romy:
Why do you suggest to add the extension on the back, not the front, as B. Edgar suggested. He specifically commented that the MOUTH area is too small and said the throat size was OK?

Herman, the mouth area determines the LF cut off, the ration between mouth area and throat area determines horn LF equalization. Bruce recommendation to extend mouth is incorrect. Extending mouth you will make a completely different horn and will be forced to change back chamber. You will end u[p with a horn that will have 5-10Hz lower but it will make it absolutely not useable in context of the Edgar setup as the mouth will be cover the MF driver. The problem with 80Hz hour is not that it need to become 60Hz horn but that it need to output 80Hz but properly, with proper equalization and with proper sound. The Bruce’s 80Hz horn is too short with too large throat. By extending the horn in the back you will continue the descending curve and will end up with smaller throat, and by this you will change the EQ of the horn. If Bruce feel that the MOUTH area is too small for 80Hz (even for 1/8 size) then it would be better do not call the horn as “80Hz horn”.

Anyhow, I did not look at the Bruce’s 80Hz horn math but just looking at it the horn strikes me as very short horn. Be advised that extending the horn in the back will not address all problems as you need to think about time-aliment, drivers integration, location of the channels and the channels vignetteing. Pay attention how Macondo is gone – it provides a lot of answers and outcome of long thinking and many experiments how to optimize multichannel horn installation. I do not propose the Macondo configuration - it takes years of playing with it in order to understand that there are no other proper configurations – but I do propose to start with the way how Macondo started L take pen and paper and begin to draw the location of the channels.
 
When I was redoing my bathroom then my plumber measured all new appliances and give me an AutoCAD drawing of my new bathroom with all appliances vertically installed. He begin to break walls and run pipes only after we have an absolute agreement what and where will be installed and how it will be related to each other. How would you feel if you are a plumber and I after you are done and tiles are laid I asked you to put a shower of opposite wall of to place a jacuzzi in place of bidet? I think an advice to “fix” horn by extending it’s month is very much from the same ploy….

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
10-26-2010 Post does not mapped to Knowledge Tree
el`Ol
Posts 225
Joined on 10-13-2007

Post #: 8
Post ID: 14789
Reply to: 14787
Schmackshorn
fiogf49gjkf0d
If it has to be a horn for ideological reasons you could try the Schmackshorn for 8-10" bass driver. I haven't heard it myself, but it has strong following in Germany.

http://www.google.de/images?q=schmackshorn&hl=de&prmd=ivfd&source=lnms&tbs=isch:1&ei=GsLGTJ_CCpHNswajtpztDQ&sa=X&oi=mode_link&ct=mode&sqi=2&ved=0CBEQ_AU
10-27-2010 Post does not mapped to Knowledge Tree
noviygera


Chicago, IL
Posts 137
Joined on 06-12-2009

Post #: 9
Post ID: 14796
Reply to: 14761
Tube amp success
fiogf49gjkf0d
I do not know why but as I listen to the 80hz Edgar horns more and more driven by the Dynaco tube amp I begin to really like the sound. Even in their untouched form there is some righteousness to the sound. I almost do not hear any serious deficiencies anymore, which is completely unexpected.
This is the the range of 80 to 350hz I am talking about and I am coming to the conclusion it is only possible to properly produce this range with tube amplifier. There is completely no more harshness in the sound, it flows softly, naturally and without bringing any attention to itself.

Actually this is very close to what I was hoping for but I did not expect that using a decent tube amp would nearly take care of the deficiencies of the horns I was concerned with before. Is it possible it was not the horns but the digital amp causing all this nonsense? I am beginning to believe this because I cannot see any other explanation.

Of course the 80hz horns have still some problems, but they are completely disproportional to the damage that the digital amplifier was creating.
Moral of this story:
If you are using Edgar 80Hz straight horns, driving them with Spectron digital amp, are unhappy with the sound, DO NOT replace the horns!
First replace the digital amp with a decent tube amp. Then listen and enjoy the Edgar horns until you hear problems again, only then think about replacing them.

I now have to listen for a while and reanalyze their sound but it's strangely good.

Herman
10-27-2010 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,486
Joined on 05-28-2004

Post #: 10
Post ID: 14798
Reply to: 14796
I will shut up and will wait until you hear it.
fiogf49gjkf0d
Herman,

I am glad that you feel better about sound from your midbass horns. I do not know what damage digital amps incur but even your experience of hating the sound of those horns to falling in love with them just after changing the amp do suggests me that the horns are wrong or your analyses of results is inaccurate. An upper bass horn shall not react like this to amplification – this is how ported enclosures react. Nevertheless, sine you feel unruffled anymore there is no reason to continue this conversation. If you would like to go to the bottom of it then create frequency response of the driver of the open air and compare it with the driver in horn. This will be what I call the equalization curve and it will gave to you more or less objective picture if you horn is too short and the throat is too large. I full they are but I will shut up and will wait until you hear it….

Rgs, Romy


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
08-25-2011 Post does not mapped to Knowledge Tree
noviygera


Chicago, IL
Posts 137
Joined on 06-12-2009

Post #: 11
Post ID: 16869
Reply to: 14798
Back to the upper bass horns
fiogf49gjkf0d
After living for a few years with Edgar 80Hz straight horns, I've had many urges to find a better sounding solution. I have a reason. Every time I turn them off and continue listening without them I notice that something good happens to the sound. It cleans up and becomes more engaging. So I am back to my search for the upper bass horn. I've decided I do not want to mess around trying to fix or improve the Edgar horns, let's forget them.

Upper crossover point is 400Hz. How low will depend on how compromised the design is. I have 40"x35" spot below my mid horns. So maybe 80 to 120 Hz bottom range. Any ideas how to start this interesting project?

1. horn shape: rectangular ok or strictly circular or something inbetween?
2. flare type
3. driver: I am thinking 10" or 12" Precision Devices.

I assume the Macondo upper bass channel is very close to a no-compromise design. I am willing to trade off a little bit for size reduction and a more practical shape but not nearly as bad as the Edgar 80Hz. If I were to theoretically place my goal design on a scale between the Edgar 80hz and Macondo Upper bass channel, my preference would be much closer to the Macondo. Is this a reasonable inquiry?

Thank you,
Herman



08-26-2011 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,486
Joined on 05-28-2004

Post #: 12
Post ID: 16871
Reply to: 16869
Eventually people learn!!!
fiogf49gjkf0d
 noviygera wrote:
Every time I turn them off and continue listening without them I notice that something good happens to the sound. It cleans up and becomes more engaging.

I am glad that somebody got in the end HOW to evaluate an acoustic system. If your upperbass is properly setup and do it’s best (a VERY big if, BTW) and of removing of it improves sound then there is no further question shall be asked about the benefits of the given channel.

If you have the 40"x35" spot below mid horns then you know your horn rate.  No you need to figure out what length of the horn you will be able to time-align and integrate in your setup and length will give to you the size of your throat. From there you might start to pick a driver. Before you let yourself to be involved into this “interesting project” spend some effort to design the entire look and feel of your entire speller, not only upperbass horn. Your upperbass horn need to be a part of the all system, so think about the frame, about the connection between upperbass and MF, about the location of other channels, about the location in the room.  To make a proper upperbass is not hard to make upperbass organically natural to the rest of acoustic system is much more noble task in my estimation.

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
08-30-2011 Post does not mapped to Knowledge Tree
noviygera


Chicago, IL
Posts 137
Joined on 06-12-2009

Post #: 13
Post ID: 16885
Reply to: 16871
Some aspects are forming
fiogf49gjkf0d
Hello Romy, thanks for your guide.

I've been thinking and I feel that some basic upper bass channel ideas are forming; they a result of, as you say ,"organic" derivation from the rest of my acoustic system. I am pretty excited about this idea i have. The rest of my system is a midrange (10" driver)and high midrange (4" driver) horns and they are of the same design, just of a different scale. They start as round at the throat and morph to rectangular towards the mouth, with very interesting phase plugs that forms a compression chamber,  and a diffraction slot at same time:
FunktionOne resolution.JPG

Resolution 1.5.jpg

So my idea is to mimic the design of these in the upper bass channel but without the phase plug. So it will be a tractrix horn that starts round and ends rectangular at the mouth. I see two main advantages of this approach:
1. larger horn mouth area without blocking the midrange sound projection, in comparison to a circular mouth of the same area
2. similar design approach to rest of system -- organic extension of other channels
3. the resulting smaller mouth height will give me more freedom of choosing the depth of the horn and in turn I can select between different diameter drivers.

So this is the theory.

Other thoughts that are suspending this development are related to the driver selection. Precision Devices are the drivers (paper cone) used in the mid and high horns and so my natural attraction to try Precision Devices driver for upper bass. 12" or 15" maybe.  Is it reasonable to assume that a 15" can be crossed at 400Hz (2nd order crossover) and sound clean?
I am not sure about this so my 2nd choice is a 12" maybe even a 10" driver.
And one last thing for now I'd like to ask you. Would you know of a builder in the USA that can design the horn based on my requirements so that I do not attempt to be a horn designer?
I can get the design built locally.

Thank you,
Herman


08-30-2011 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,486
Joined on 05-28-2004

Post #: 14
Post ID: 16886
Reply to: 16885
A few approved candidates for horn consulting.
fiogf49gjkf0d

 noviygera wrote:
And one last thing for now I'd like to ask you. Would you know of a builder in the USA that can design the horn based on my requirements so that I do not attempt to be a horn designer? I can get the design built locally.

Herman,  I am not exactly understand what kind upper bass you would like to get. Not that I need to but it looks like if you have your hart set then it is good. I do like that you think about your future upper bass channel as a complete package with respect to the existing channels.

Anyhow, you are looking for a person who would help you with design of your horn. It would be all depends from what kind help you need. I do not know if you looking for basic geometry of your design or if you need the detailed bulling plan. In case you need both, that in my estimation what you need then do not deal with online idiots who like to run mouth about horn but never build anything themselves or never made anything to sound respectably positive. You need somebody who has experience with materials, building methods results, intellectual and cultural capacity to interpret result and who will be able to give you further recommendation after the horn are built and you will be trying to make it to sound appropriate. Just from the top of my head her are a few named right here in US:

Bruce Edgar from California. He is pretty much a Godfather of horn building in States for our generation and he is incredibly experienced person who will be able to accommodate any service you require. The minor problem that you might have with Bruce is that quite many of his past and present customers are or retarded idiot of bottom-eating white trashes and as a result many of the Bruce’s “designs” and ideas are structured for much more simplistic and cheaper implementation then it shell be. Do not be fooled by frugality and stinginess of Bruce ideas. He knows very well what and how the things need to be done, he has perfect ability to understand sound and if you slightly multiply and make more expensive the implementation of his design and recommendation then you will hardly find any more qualified consultant.

John Hasquin from Tennessee or Kentucky, I am not sure where he lives now. John is quite unique person in my estimation: he has a lot of practical building experience, great ability to understand and to interpret results and in the same time he for some reason does like to waste his time with internet idiots of DIYAudio.com level. John will be able to consult you in all aspects of your project and I very much HOW he interact, approach and flow up with problems. You can find him shepherding Morons at DIYAudio.com and I do advise to pay attention to his online output.

Jeffrey Jackson from Tennessee or Arkansas, I am not sure where exactly he lives. Jeffrey is another representative of next generation of horn makers and I do like his thinking and his “making”. Jeffrey among all have tendency to go for off the beaten past projects. So, if you are trying to go for something “dangers” then Jeffrey might be your partner. From my conversations with Jeffrey I feel that is very intelligent in Sonic language not to mention the building know-how and he might be another perfect candidate for your project.

I would like to note that any of the mentioned people are no-nonsense and no BS-type of people. You need to have very strong sense what you want to do and do some of your home work in order to form objective for those people in the format that would make them beneficial to you. Do not dump to them your general frustrations but be specific what you know, what you are trying to accomplish, what you do not know and what you expectations from their services might be. BTW, it is high likely that they might build the things for you as well and this would be much more preferably then your local builder who never dealt with Sound.

Rgs, Romy the Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
10-21-2011 Post does not mapped to Knowledge Tree
noviygera


Chicago, IL
Posts 137
Joined on 06-12-2009

Post #: 15
Post ID: 17206
Reply to: 16886
Return to the inescapable
fiogf49gjkf0d
Romy,

I have made honest attempts to contact the recommended horn designer candidates, but with no result. I do not know why but it looks like they are not seeing me, or responding. Like walking down the street and observing pedestrians looking though me as if I am transparent. I have to do this project on my own now but I am not informed or knowledgeable. So I would like to ask for some guides from those who can share their knowledge:

I have an idea of my available space. It is maximum 36" deep for the horn flare. I have additional space for the back chamber. I have more flexibility in the mouth size, it can be made quite big if necessary, up to 34" x 30", or alternatively 30" round.
I have listened to various 12" and 10" drivers, just for fun, without mounting in a box. Always, the 10" drivers sounded better in my opinion. The word "better" will require a separate thread for explanation, but in short, they are cleaner. So my preference is to use a 10" driver if possible.

What changes in the horn dimensions between 10" and 12" driver?

Lower cutoff will be dictated by design, I have no requirement as long as its below 150Hz.

Will anyone be able to understand my situation and help out? We'll see.

Herman
10-22-2011 Post does not mapped to Knowledge Tree
Jorge
Austin TX
Posts 137
Joined on 10-17-2010

Post #: 16
Post ID: 17208
Reply to: 17206
Help
fiogf49gjkf0d
Noviygera, I guess I can do something about this if you want to contact me privately.

jsadurni at ecovortec dot com


10-23-2011 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,486
Joined on 05-28-2004

Post #: 17
Post ID: 17211
Reply to: 17206
Project management problems?
fiogf49gjkf0d
Herman, horn dimensions does not described by size of driver but only size of throat. It will be absolutely nothing changed in the horn dimensions if you go from between 10" and 12" driver. Sure you would need a bit larger back side of the horn to accommodate larger driver and if you use the size of throat you will have more compression with larger driver. To assess how it will affect sound is absolute imposable. Some of the drivers are fine to work in too small throat, some not. Put in the perspective the variable size of back chamber and variable of the lading from amplifier and you have absolutely unpredictable situation when the only empirical tests can indicate something. Frankly I do not take seriously your preference of one driver over another driver. If you heard them “just for fun, without mounting in a box” then what you hears was absolutely irrelevant and their performance in the horn, in the back chamber will be absolutely different.

I am not sure what you are doing and what you are looking. My view is that to find a horn builder is not complicated task. It is much more complicated to figure out what you want and how you want the things done. It is like building a house. It is not complex to cut wood, poor concrete and attach pipes. It is much more complicated to evaluate life style and come up with a design what house shall be and what it have to future. Trust me, if you have a very definitive idea what you want then the builder will run to you, literally. If you have flimsy frustration that you just want something but not quite sure what you want then some experienced boulders would prefer to stay away, unless they are absolutely broke.

I do not insist that it was what happened in your case but what I discovered with my contractors that I hired to work on my house was that the best way to be invisible is do not have firm expectations from this service.

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
10-25-2011 Post does not mapped to Knowledge Tree
noviygera


Chicago, IL
Posts 137
Joined on 06-12-2009

Post #: 18
Post ID: 17223
Reply to: 17211
What I need is a horn architect
fiogf49gjkf0d
I understand that "nothing changed in the horn dimensions if you go from between 10" and 12" driver". You are referring to the horn mouth I assume. Do you have a idea what compression ratio is good to have for upper base horn? It seems that 2:1 is talked about for the tractrix by few people here.
So far I have this information:

120Hz horn mouth -- but is that in quarter space or full space?
Tractrix flare
10" or 12" paper driver

There are a few drivers that 10" or 12" paper cone, have very high eff, and also high Fs. Precision Devices, 18 Sound, Beyma, Ciare, Faital, B&C.

Romy, how did you choose your 8" driver from so many other drivers out there? Did you decide on the size first, and then narrowed down your search and then built the horn for that specific driver or the other way around?
I do need to start somewhere.

Herman

10-25-2011 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,486
Joined on 05-28-2004

Post #: 19
Post ID: 17224
Reply to: 17223
You need to stop deceive yourself.
fiogf49gjkf0d
Herman, how I did it is not the subject for imitation or following. If you insist that you need to “start somewhere” then the best you can do is stop bothering your with all those BS concepts like mouths size, compression ratio, drivers brands, quarter space vs. full space. At this point they are juts buzz words for you and you are trying to toss them like placing cards feeling that it gives any meaning for your thinking. In reality is just sends a message that you are nowhere near where you need to be if you want to “start somewhere”.

The point that I am trying to make is: stop to polite your mind with meaningless buzz words and deal with the problem as you face them. I have no idea what you are trying to do but if you are planning to build up some kind of acoustic system then start from planning, sketching and drawing. Who care what are your questions or your thoughts about quarter space, resonance frequency or compression ratio are if all of it has no context. Please, not take it personally and do not take it as a criticism. You are not forming any meaningful question worthy answers, and you not form it not only to other but the most important to yourself. I personally tend to discard any efforts if I feel that they are just tire kicking and do not have any substance behind, which is ironically would be 95% of internet audio posts….

Rgs, the Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
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