| Search | Login/Register
   Home » Horn-Loaded Speakers» The absolutely “best” material for horns construction. (42 posts, 3 pages)
  Print Thread | 1st Post |  
Page 2 of 3 (42 items) Select Pages:  « 1 2 3 »
   Target    Threads for related reading   Most recent post in related threads   Forum  Replies   Views   Started 
  »  New  Jessie Dazzle Project..  Will this better to be auditable?...  Horn-Loaded Speakers Forum     172  1509197  08-03-2007
  »  New  Some nice horns from Greece!..  The MF horn supporting frame...  Horn-Loaded Speakers Forum     1  23864  02-22-2008
08-02-2009 Post does not mapped to Knowledge Tree
el`Ol
Posts 225
Joined on 10-13-2007

Post #: 21
Post ID: 11263
Reply to: 10953
Discussion on diyaudio
fiogf49gjkf0d
http://www.diyaudio.com/forums/showthread.php?s=&threadid=148406
08-07-2009 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 10,049
Joined on 05-27-2004

Post #: 22
Post ID: 11303
Reply to: 6761
The double-layering horn speakers.
fiogf49gjkf0d

I have no comments about it besides assuring that the company that state all of it does crap in term of Sound. Still, I find that the way in which they think about construction of the walls of their back-loaded horn worth very much attention. Take a look:  

(Free-Press-Release.com) June 23, 2009 -- Many commercially available loudspeakers are closed-box enclosures and bass-reflex enclosures. Reasonably-priced backloaded horn speakers are not many because of internal complicated structure. So, many audio nuts made that by oneself. However, Hasehiro Audio achieved a low price. Moreover, they succeeded to eliminate right-angled bend. (i.e., elimination of a hollow-gray sound)  You can get yearning exponential backloaded horn speakers at last. Let's be intoxicated by a beautiful curve makes authentic backloaded horn sound.

1. The First Concrete Horn By Mr.Imanari:
- In about 1975, Mr.Imanari (Audio nut and director of invention school) introduced own invention at the floor.
- That's the first concrete backloaded horn speaker. - cubed concrete, 10cm unit and 2.5m long backloaded horn.
- Hasehiro requested the production to Mr.Imanari momentarily.
- After that, he got some orders by mouth-to-mouth advertising.
- But they take up to over 1 year from ordering to reception because he was hung up on new invention.
- As a result, it went of mind of audio nuts by little and little.

2. Batonpassing:
- In about 3 years after completion the first concrete backloaded horn speaker, Hasehiro thought - this is so wasteful that it has a tremendous amount of potential and anyone think of nothing to concrete backloaded horn and the making. - Hasehiro told his long-held aspiration to Mr.Imanari and he made a promise the tool passing and initiation of the technical know-how.
- But before that, Mr.Imanari was taken with illness and passed away after several months in a hospital.
- His heart swelled with put that out into the market for answer to the will of Mr.Imanari.
- Hasehiro told the antemortem promise to the bereaved family, and he received some undisposed tools from them.
- Hasehiro made trial model over and over imagining the making process from the tools.

3. Study From Fabric:
- Concrete characteristic vibration harden the tone color.
- So first, Hasehiro was starting to amelioration of concrete fabric.
- He changed black cement to white cement and also he changed aggregate and mixed in particular absorb sound chips.
- As a result, Hasehiro succeeded to remove concrete-specific sound character and could get the fabric know-how.

4. Pronouncement:
- In 1990, Hasehiro Audio submitted the model "AX" (discontinued) used 12cm unit to The International Housewares Show.
- After that, Hasehiro Audio submitted the succession model "HoPe-twoBx" (discontinued) used 16cm unit to the exhibition and they receive orders from after too.

5. Challenge To Double-Layered Structure:
- Hasehiro had wondered for a long time making the upper grade model used 20cm unit.
- But it looks about 50kg from specific gravity of concrete.
- So, it is difficult to distribute and had to give up.
- However, one audio nut suggested the double-layered structure of wood and concrete for not only weight saving but also think it should be a natural sound more add to wood sounding.
- Hasehiro had a lot of trouble. - cracks in the concrete when drying etc.
- But Hasehiro could resolve that for technical guidance from Onoda Cement Co., Ltd.
- In 1997, completed the world's first backroad double-layered horn speaker. - WCW-200A (discontinued)

6. Wood with Concrete Horn:
- That's a fusion with Japanese cement technology.
- WCW series is the backloaded horn speakers of double-layered structure. - implant concrete horn directly into wooden enclosure.
- WCW series reproduces unbelievingly clear and realistic sound. - controls resonance by wonderful integration of wood and concrete.
- Concrete horn of high radiation efficiency. - profound low tone and margin of high efficiency.
- That's not mere loudspeakers anymore.
- That's the exact live reappearance equipments.
- WCW series gold titled in eliminate tube amp category of The Vacuum Tube Audio Fair in Akihabara from 1998 to 2000, 2002 and 2003 (From 2004, no elimination races)

That's "Hasehiro Premium"

Seigo Terasaki
Minister and CEO
TelaWorks Corporation
http://telavox.web.fc2.com


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
08-16-2009 Post does not mapped to Knowledge Tree
decoud
United Kingdom
Posts 247
Joined on 03-01-2008

Post #: 23
Post ID: 11433
Reply to: 11303
Variable profile horn system
fiogf49gjkf0d


One of the problems with horns is the inflexibility of frequency cut-off: you are limited to a discrete number equal to the number of horns you have. This makes experimentation difficult without having an absurdly large array of different horn sizes to try. So how about the following configuration:

VARIABLE_PROFILE_HORN.jpg

The entire loudspeaker is a single profile that changes continuously in cross section from floor to ceiling with high frequencies being in the centre and low at the extremes. Any cut-off frequency is therefore always available (in two positions): it is simply a matter of driver positioning. Equally, the only limit on the number of "horns" is the number of drivers. Removable horizontal septations can be introduced if necessary but it would be nice to do without them.

Once the optimal profile is determined the thing would be trivial to build: it could be just a series of CNC'd slabs of mdf stacked on top of each other.

Rgds, d
08-16-2009 Post does not mapped to Knowledge Tree
JLH
Indianapolis, IN U.S.A.
Posts 42
Joined on 07-20-2004

Post #: 24
Post ID: 11436
Reply to: 11433
Just a variation of the unity horn
fiogf49gjkf0d
 decoud wrote:


One of the problems with horns is the inflexibility of frequency cut-off: you are limited to a discrete number equal to the number of horns you have. This makes experimentation difficult without having an absurdly large array of different horn sizes to try. So how about the following configuration:

VARIABLE_PROFILE_HORN.jpg

The entire loudspeaker is a single profile that changes continuously in cross section from floor to ceiling with high frequencies being in the centre and low at the extremes. Any cut-off frequency is therefore always available (in two positions): it is simply a matter of driver positioning. Equally, the only limit on the number of "horns" is the number of drivers. Removable horizontal septations can be introduced if necessary but it would be nice to do without them.

Once the optimal profile is determined the thing would be trivial to build: it could be just a series of CNC'd slabs of mdf stacked on top of each other.

Rgds, d


What you have there is Tom Danley's Unity Summation device in principle. Tom has a predictable method that limits the trial and error approach. It would be very difficult to get the frequency response flat for your example. The distance between the drivers is too great and will result in a lot of phase and timing problems.

08-16-2009 Post does not mapped to Knowledge Tree
decoud
United Kingdom
Posts 247
Joined on 03-01-2008

Post #: 25
Post ID: 11437
Reply to: 11436
Not summation but continuity
fiogf49gjkf0d
Perhaps I misunderstand the unity horn, but I did not mean my suggestion to depend on summation: the idea simply is that one horn flows directly into the other, rather than being discrete; you could have the bottom or top half alone. So the profile is still tractrix (say) it is just that it merges smoothly into its neighbour. The drivers need not be any further apart than they are in a conventional horn system configuration. Would that not work?
08-16-2009 Post does not mapped to Knowledge Tree
JLH
Indianapolis, IN U.S.A.
Posts 42
Joined on 07-20-2004

Post #: 26
Post ID: 11440
Reply to: 11437
It will not work
fiogf49gjkf0d
 decoud wrote:
Perhaps I misunderstand the unity horn, but I did not mean my suggestion to depend on summation: the idea simply is that one horn flows directly into the other, rather than being discrete; you could have the bottom or top half alone. So the profile is still tractrix (say) it is just that it merges smoothly into its neighbour. The drivers need not be any further apart than they are in a conventional horn system configuration. Would that not work?


It does matter how you want to intellectually dissect your example, it is in principle still a summation device. In order to get a flat frequency and phase response, the output from each driver must sum correctly at their crossover point. Your example only differs from the unity horn in the driver locations. There will not be anything approaching continuity between the drivers because they are multiples of wave lengths apart at their perspective crossover points.

08-17-2009 Post does not mapped to Knowledge Tree
JLH
Indianapolis, IN U.S.A.
Posts 42
Joined on 07-20-2004

Post #: 27
Post ID: 11462
Reply to: 11440
PDF link to Unity horn patent
fiogf49gjkf0d
Unity horn Patent link. It is very easy to understand how each segment of the conical loads the different frequenices.

http://www.pat2pdf.org/patents/pat6411718.pdf

U.S. patent 6411718
08-18-2009 Post does not mapped to Knowledge Tree
decoud
United Kingdom
Posts 247
Joined on 03-01-2008

Post #: 28
Post ID: 11482
Reply to: 11462
Unity horn design
fiogf49gjkf0d
Very many thanks for the link: I shall take a look.

I know you have built tapped horns yourself, JLH, but have you tried the synergy horn approach and seen how it compares with conventional horns? Danley's kit seems to be targeted at large venue high power applications, so hard to know how it would deal with low power SETs of the kind we are interested in.
08-19-2009 Post mapped to one branch of Knowledge Tree
JLH
Indianapolis, IN U.S.A.
Posts 42
Joined on 07-20-2004

Post #: 29
Post ID: 11490
Reply to: 11482
Low power SET is not a problem.
fiogf49gjkf0d
Low power set should not be a problem. The Unity was fine with SET amplifiers, so the Synergy should be no different, if not better. The Synergy horn is different than the original Unity horn. There are some very specific improvements in the Synergy horn, so significant that another patent covers it. See following link for Synergy horn patent application:

http://www.wipo.int/pctdb/en/fetch.jsp?LANG=ENG&DBSELECT=PCT&SERVER_TYPE=19-10&SORT=41270106-KEY&TYPE_FIELD=256&IDB=0&IDOC=1468907&C=10&ELEMENT_SET=B&RESULT=2&TOTAL=5&START=1&DISP=25&FORM=SEP-0/HITNUM,B-ENG,DP,MC,AN,PA,ABSUM-ENG&SEARCH_IA=US2006022032&QUERY=%28IN%2fdanley+AND+IN%2fthomas%29

Sorry for the long link – just click or copy and paste into your internet address bar.

Anyway, the thing that sets the Synergy apart from the Unity is its phase coherence. This is achieved through some very specific design steps.

1.) The mid or low frequency driver(s) that tap into the horn are electrically bandwidth limited (crossover) below the point where you get the first high frequency cancellation notch. The cancellation notch is created when the distance from the tap point to the apex (compression driver voice coil) is equal to half a wavelength. Some clarification is needed here. This is really not an actual physical distance, but an acoustical distance. This is because the apparent acoustic center of the compression driver and the mids/low drivers do not occur at the voice coil. However, it is not too hard to figure this out with the help of AkAbak simulation software.

2.) The cross sectional area where the mids/lows tap into the horn is such that the circumference is equal to or less than one wavelength of the highest frequency you want it to produce. For example, if your mids tap into the horn where the cross sectional area is 93.5 sq cm, then you would not want to have it produce anything above 1KHz.

3.) The tap point of the mids/lows must have a local expansion rate equal to, or lower than the lowest frequency to be produced. For example, if you want the mid to produce down to 300Hz, then the flare rate at the tap point looking forward toward the mouth must look like a 300Hz or lower flare rate.

4.) The ports or ducts that the mids/lows tap into are not cylindrical in shape. Either they appear as conical, or as a counter bore shape. They are described as being frustoconical in the patent application. This greatly reduces the acoustical impedance of the ports, so you can use a smaller diameter port without running into compression problems. Long and large diameter ports decrease bandwidth and SPL which are things we are trying to avoid.

Overall, the Synergy design is a substantial leap in performance over a Unity. I have played around with a Unity model a few times. I never came up with a completed project. However, with the new design criteria now available from the Synergy patent I am more inclined to try it again. Even my quick and dirty attempt had some sound qualities that were very inviting. The point source and constant directivity behavior was very pleasing. It did not have any of the problems associated with multiple horns such as lobbing and narrowing directivity.

Inclosing, I heard the Danley SH-50 at a dealer in Pennsylvania. It was shocking how coherent it was. The intelligibility and how it was able to flesh out details and separate all the sounds was very surprising. Each sound came from a stable and correct position from within the sound stage. I might say it sounded almost too hi-fi to me. Of course personal preference will play into this. However, I can see people using this speaker in their HT setups with excellent results.
08-19-2009 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 10,049
Joined on 05-27-2004

Post #: 30
Post ID: 11492
Reply to: 11490
The Synergy design… and antiskating
fiogf49gjkf0d

John, I have to confess that I feel very not easy about the idea of Synergy horn. I did not hear the Danley Synergy horns and I have very superficial understanding of what he is trying to do with the whole Synergy/Unity idea. The whole idea does not make very horny, pun intended….

One of the theoretical premises of my understanding of horn loading is for any given loading application there is an infinitely-small bandwidth of “ideal loading”. The “ideal loading” is not a field but rather a single point similar to antiskating with pivoted tonearms. A perfectly balance antiscating is a single point on the records, everywhere else are just acceptable compromises.  The same is with horns. I given single frequency has own “perfect horn” with max horn EQ, minimum acoustic low-passing and best possible other characteristics. A deviation from this “perfect narrow frequency” makes acceptable compromises.  It does not mean that a horn cannot serve 5-6 octaves but the level of acceptable compromises becomes a bit wider as the driver at lower knew stops acknowledge the horn and at higher knee become too much restricted by the horn size. Again, not saying that it is unusable but I am just explaining the concept.

Not let look at the Synergy design. Let leave aside the way how Mrr. Danley proposes to integrate the drivers and let look at the Synergy idea only from a perspective of best horn for a best given driver. We would see that the mid drivers in Synergy might have own “best” lording but the high and low drivers do not. The LF driver looks like loaded into an insufficient re-entry horn and the HF drivers see also very far from optimum horn. Is it a too high price to pay for point source, particularly considering that I do not support  the notion that a point source is necessary better than 3D source?

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
08-19-2009 Post does not mapped to Knowledge Tree
JLH
Indianapolis, IN U.S.A.
Posts 42
Joined on 07-20-2004

Post #: 31
Post ID: 11493
Reply to: 11492
I'm not trying to promote the Synergy
fiogf49gjkf0d
First let me say I am NOT trying to promote the Synergy horn. I just think it is very intresting to look at and to think about.

Ideal loading only occurs at a singular frequency within any horn. This ideal loading point is where the length is 1/2 a wavelength and the circumference is equal to 1 full wavelength. Since the acoustic size of the wavefront is exact in relation to the horn, ideal loading occurs. Any frequency above or below this is not being loaded in an ideal way. Therefore, there is not a horn that exists that can achieve ideal loading across the horn’s whole bandwidth. In addition, there is no such thing as the perfect driver for a horn. There is only a singular frequency point there a driver will be perfect for the horn it is mounted to. (I'm not discussing Tone, just loading) All drivers mounted into all horns are compromises as soon as they play any frequency that is not exact fitting. So, to me the whole ideal loading thing is a moot point.

I do not believe you fully understand what Danley is doing with the Synergy horn. Each driver is loaded in the most idea way with the least amount of compromises. A curved wall horn holds the same flare rate throughout its entire length, a conical horn does not. The reason why Danley uses a conical horn is its variable flare rate nature. At the apex (throat) of the horn, the flare rate is fast. As you progress closer to the mouth, the flare rate decreases. This high flare rate at the apex (throat) is ideal for loading the compression driver. The mids are mounted further down the horn where the flare rate is appropriately slower for their operation and this continues for the lows.

Real world example of the flare rates inside of Danley SH-50: the SH-50 is a 50 degree conical horn. The mids tap into the horn at around 2.78 inches. The distance from the compression driver’s diaphragm to the mid tap point totals 3.66 inches. The area of expansion is from 0.24 square inches to 11.29 square inches. This equates to a flare rate of 1132Hz loading the compression driver. The electrical crossover is around 1200Hz, so the compression driver is operating within a very ideal way. Since the wavelengths within the compression driver’s range are acoustical small in relation to the rest of the horn, it’s sound is not harmed by the rest of the horn. The same is true for the mids and lows. I have ran through the math it all adds up.

Each driver injects into the horn where the most ideal loading should occur. This also leads to the minimal phase nature of the Synergy horns. This makes the Synergy less of a compromise than a multi horn stack. I understand your underlying feelings about a multi driver horn like the Synergy. I too felt like everything we know about horn purity is being violated. However, Danley’s careful choices have resulted in a very well designed, measured, and sounding horn. I cannot argue with what my ears heard. In the end I did not believe that it is worth arguing about a horn just because its design features do not mesh well with our preconceived notions. We should just let things be the way they are and take them for what they are. I find the Synergy very intriguing. It does a lot of things very well. Would I use it in my own audio? Probably not because it is too clean and hi-fi sounding for my taste. I like my horn colorations too well. Should DIY people try to make their own Synergy? No-it is too complicated and cost too much.
08-19-2009 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 10,049
Joined on 05-27-2004

Post #: 32
Post ID: 11495
Reply to: 11493
50 degrees of separation…
fiogf49gjkf0d

 JLH wrote:
I do not believe you fully understand what Danley is doing with the Synergy horn.

Nope, I do not. Well, I understand it but I am not willing to acknowledge that I understand it as the Synergy horn idea looks too freakish to me. You do not see me arguing the Synergy idea I just feel no interest. I might feel an interest in the Danley’s creatively but to me the even to look at the Synergy horn is scare.

 JLH wrote:
  Real world example of the flare rates inside of Danley SH-50: the SH-50 is a 50 degree conical horn. The mids tap into the horn at around 2.78 inches. The distance from the compression driver’s diaphragm to the mid tap point totals 3.66 inches. The area of expansion is from 0.24 square inches to 11.29 square inches. This equates to a flare rate of 1132Hz loading the compression driver. The electrical crossover is around 1200Hz, so the compression driver is operating within a very ideal way. Since the wavelengths within the compression driver’s range are acoustical small in relation to the rest of the horn, it’s sound is not harmed by the rest of the horn. The same is true for the mids and lows. I have ran through the math it all adds up.

Are you sure that the same is for the mids and lows?  Do not take to account the fact that within the 5.56 inches the mids work as a re-entry path.  Also, I do not know how you can talk about math. Any geometry implies distance and distance implies two measuring points. In case of horn if we do not consider the re-entry paths then we have only two absolute points of distance: throat and mouth. We have a curve between them but it is not important. So, I we have a driver sitting on axes then we have a relation between the distances as the driver axes is the same as the horn axes and the driver’s exit points are equidistant to the mouth’s distances. How we have a driver that sits in the mid of the horn, with an angle of 50 degree to the horn axis.  The driver has own dimensions, let say 4” diameters of cone. So, what the hell would be “geometry” in case of this application. We have 4” smudge that describes the arrival time from the driver to the edge of the horn, then we have the re-entry reflections that smear the “distances” and “geometry” even more. I do admit that I might not understand something but I just too afraid to look in the theory of the Synergy deeper as I begin to ask myself questions that I have no answers. For instance you say that “electrical crossover is around 1200Hz, so the compression driver is operating within a very ideal way”. Ok, is it a crossover of 64dB per octave? If not then will the Synergy idea to choke with innermodulations?

 JLH wrote:
  However, Danley’s careful choices have resulted in a very well designed, measured, and sounding horn. I cannot argue with what my ears heard. In the end I did not believe that it is worth arguing about a horn just because its design features do not mesh well with our preconceived notions. We should just let things be the way they are and take them for what they are. I find the Synergy very intriguing. It does a lot of things very well. Would I use it in my own audio? Probably not because it is too clean and hi-fi sounding for my taste. I like my horn colorations too well. Should DIY people try to make their own Synergy? No-it is too complicated and cost too much.

Well, if what you say is true, even if I do not understand it, then perhaps there is no need to argue with Synergy idea but rather to heir Danley to built a set of Synergy system that would have more advanced demands then PA systems, dunk rock-n-roll punks and QSC Audio amplification.  If Dan Danley feel that his Synergy is potent to do good sound then it would be interested if he come up with home-targeted products, with “expensive” drivers and upscale demand for sound. It might be not his cap of tea (and I would not blame him) but since the proof is in a pudding it is very unlikely that a listening session in Guitar Center would pick my interest. Do you know if he does custom work? It is not something that I am interested but someone might find it worth to investigate….

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
08-19-2009 Post does not mapped to Knowledge Tree
JLH
Indianapolis, IN U.S.A.
Posts 42
Joined on 07-20-2004

Post #: 33
Post ID: 11498
Reply to: 11495
Not as bad as you think
fiogf49gjkf0d
I’m absolutely certain that the mids and lows are designed in the same function supporting fashion as I described the compression driver. Danley explicitly explains this in his patent. For my own amusement, I went through all the math and calculations and everything fell in place with what is described in the patent. The Synergy horn meets all 4 points I wrote about in my earlier post about how the Unity and Synergy are different. There is nothing scary about the Synergy, it’s just different. I can understand you may not have any desire to understand it, but that does not mean it is any less a horn.

As you know I’m well aware of the geometry and math involved in analyzing horn designs. You can’t ignore the “re-entry” paths just because it is more challenging to understand. The smearing and reflections you alleged to don’t exist. The mids and woofers operate in laminar flow and not as direct radiation into the horn. The axis of entry is irrelevant because of this. The sound emanates into the horn very much like a balloon inflating. All the re-entry ports are equal distant from one another, therefore the individual pressure wavefronts converge at the same time to construct a single in-phase wavefront that travels toward the mouth.

The crossover is not a specific slope or type. The crossover between the drivers is whatever is required to maintain phase, time, and frequency coherence.  The crossovers should be thought about more like transfer function modifiers. This too is explained in the patent.

I agree that the Synergy is interesting to investigate. Danley Sound Labs does do custom finishes on its existing models. However, I don’t think they would make a custom model unless you paid through the nose. With the thousands of dollars in large industrial installations, I don’t think Tom Danley has any interest in the Home Hi-Fi market. I don’t blame him either. We all know how much a circus Hi-Fi audio is. There have been several people trying to get Tom to design a flagship home version of his Synergy, but he has declined. That’s all I have to write about the Synergy.
12-14-2009 Post does not mapped to Knowledge Tree
JLH
Indianapolis, IN U.S.A.
Posts 42
Joined on 07-20-2004

Post #: 34
Post ID: 12477
Reply to: 11490
The Synergy patent link is broken
fiogf49gjkf0d
A member of this site asked about the Synergy horn patent link not working. I'll try to upload the PDF file of the patent for all to view. It is no fun trying to find this patent. It is difficult to search for because it has not yet been approved. I hope the upload works.

http://www.goodsoundclub.com/PDF/Synergy_Patent.pdf

Rgs, JLH
05-09-2018 Post does not mapped to Knowledge Tree
xandcg


Rio de Janeiro, BR.
Posts 218
Joined on 09-07-2014

Post #: 35
Post ID: 24830
Reply to: 10953
Two products.
Two interesting products from Duayen, what seems to be a business from Turkey.

https://www.youtube.com/watch?v=AzYxw_h-n_s
https://www.youtube.com/watch?v=Imx2a2E0RyU



Think for yourself, do not be sheep.
05-14-2018 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 10,049
Joined on 05-27-2004

Post #: 36
Post ID: 24832
Reply to: 24830
Sure a great material, so what?
Indeed it is a very fine product, in fact very impressive but I do not know what it has to do with building horns. Strength is not the quality in my view that is necessary for horns construction. The maternal also can be used as mold as it sticks to a surface. 


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
05-14-2018 Post does not mapped to Knowledge Tree
xandcg


Rio de Janeiro, BR.
Posts 218
Joined on 09-07-2014

Post #: 37
Post ID: 24842
Reply to: 24832
Finishing.
Those materials may be interesting to be used as finishing/primer to avoid degradation of the (polymer) concrete horns. And at least one of them can also be applied on wood.
I, of course, do not have idea how any of those products would interfere in the horn sound but would be worth to test in some small horn to know.
Cheers!



Think for yourself, do not be sheep.
09-13-2019 Post does not mapped to Knowledge Tree
xandcg


Rio de Janeiro, BR.
Posts 218
Joined on 09-07-2014

Post #: 38
Post ID: 25592
Reply to: 24842
Steel/Aluminum or polymer concrete?
What would be a better material for horns, specially large ones, steel/aluminum or polymer concrete? Do metal horns be the right choice in general?

I just remembered I could ask some favors and have large steel/aluminum horns made by high skilled people in some shipyard.

Thanks!



Think for yourself, do not be sheep.
09-24-2019 Post does not mapped to Knowledge Tree
xandcg


Rio de Janeiro, BR.
Posts 218
Joined on 09-07-2014

Post #: 39
Post ID: 25609
Reply to: 25592
Aluminum thermal expansion.
I found THIS data about the aluminum thermal expansion and I understand it looks like pretty low.
I am particularly thinking about 'Aluminum 7075', btw.

Another thing that came to my mind is aluminum hulls tends to be quite noisy (steel hull not); however I don't know if the same would apply in a horn!

Also, for aluminum and steel, black oxide (and other oxide types) could be used instead of painting, and/or powder coating too.



Think for yourself, do not be sheep.
05-25-2022 Post does not mapped to Knowledge Tree
Monette
Boston, MA / NYC
Posts 1
Joined on 05-25-2022

Post #: 40
Post ID: 26784
Reply to: 6769
Structural flaws with polymer concrete when dealing with large and complex shapes; stress fractures and reinforcement
"Other uses for polymer concrete have spun out of its use for counter tops, which can be large enough that cracking becomes an issue.  Hearths, sinks and even Roman style tubs have been constructed of this material.  Variations in the aggregates, reinforcements and polymers have resulted in a fairly stable material that might also be used for speaker enclosues, and mold shapes keep getting more elaborate. There is no doubt that this stuff could be used for horns to good effect, and some aggregates treated right might yield surfaces that required mimimal further finishing.  At the same time, it is possible to build up this material, so fine tuning - in the + direction at least - would likely be pretty easy.  Grinding it is possible, too, but not so simple.  Shrinkage of modern polymer concrete is minimal to negligible.  Lightweight aggregates are also in widespread use, along with ground glass and other materials chosen to enhance finished appearance."
It might work to have polymer concrete base with something along the lines of a shaped metal reinforcing or perhaps a composite materiel outer shell. Perhaps after the concrete has cured a layer of fiberglass or CFRP could be layered over it, using the inner mold of the concrete as a structural support, during the vacuum bag and autoclave process. It would leave the internal finish and all the desired properties of the concrete while maintaining a light weight but strong supporting shell. There are some self curing reinforced composites that could make it easier to produce as well. This would also have the advantage of allowing the actual concrete section to be overall lighter as it wouldn't need to be so thick to support its own weight, which would improve the lives of speaker designers more than anything as the horns would be easier to mount. It would add difficulty to the manufacturing but might be worth it.
Page 2 of 3 (42 items) Select Pages:  « 1 2 3 »
   Target    Threads for related reading   Most recent post in related threads   Forum  Replies   Views   Started 
  »  New  Jessie Dazzle Project..  Will this better to be auditable?...  Horn-Loaded Speakers Forum     172  1509197  08-03-2007
  »  New  Some nice horns from Greece!..  The MF horn supporting frame...  Horn-Loaded Speakers Forum     1  23864  02-22-2008
Home Page  |  Last 24Hours  | Search  |  SiteMap  | Questions or Problems | Copyright Note
The content of all messages within the Forums Copyright © by authors of the posts