gedlee said:
The longer and narrower *the nearer to a plain wave tube* the less the HOMs density? Did I get it right?
salas said:
The Avant Garde doesn't use any termination - that's a recipe for all kinds of nasty reflections from the mouth.
Every time I've heard them I've found them enjoyable for the first few minutes, then the sounds begins to grate on the nerves. This seems to be the case with all horns with poor termination. I had the same problem personally with the tractrix horns I built years ago. They measured well, but you couldn't listen to them for long.
I have listened to a pair for a few hours and find them very sensitive to amplifier setup configurations.Patrick Bateman said:
Re: Waveguide worksheet
Hi Ed,
I have started modifying the Hornresp Horn Segment Wizard so that it will be possible to generate construction data for an axisymmetric OS waveguide having a non-zero throat entry angle.
If all goes according to plan, it should only take me a week or so to get everything working and tested.
I will let you know when the update is released.
Kind regards,
David
Ed LaFontaine said:
Hi Ed,
I have started modifying the Hornresp Horn Segment Wizard so that it will be possible to generate construction data for an axisymmetric OS waveguide having a non-zero throat entry angle.
If all goes according to plan, it should only take me a week or so to get everything working and tested.
I will let you know when the update is released.
Kind regards,
David
gedlee said:
Hi Earl,
Just to clarify - the Avantgarde speaker is actually a spherical horn, which is slightly different to a tractrix horn. The two profiles can be compared in Hornresp.
Kind regards,
David
David McBean said:
I don't have Hornresp - could you explain the difference? They are both just contour drawn on a piece of paper with no real theoretical justification correct? Doesn't the center of the circle defining the contour move forward at a different rate?
subwoofer questions
Do you think those studio monitor subwoofers would be good from home audio use?
For example, yamaha has this 8" bass reflex sub:
http://www.guitarcenter.com/Yamaha-...o-Monitor-Subwoofer-601419-i1153008.gc?Mode=5
I am thinking maybe a pair of these guys for 80hz and below. Maybe add a third sub for 20hz-40hz. My room is around 12' x 17' x 8'.
Do you think those studio monitor subwoofers would be good from home audio use?
For example, yamaha has this 8" bass reflex sub:
http://www.guitarcenter.com/Yamaha-...o-Monitor-Subwoofer-601419-i1153008.gc?Mode=5
I am thinking maybe a pair of these guys for 80hz and below. Maybe add a third sub for 20hz-40hz. My room is around 12' x 17' x 8'.
Re: subwoofer questions
They seem very expensive for an 8" sub. I have a guy in New Orleans who is supposed to make 10" units that I designed for the same price. But, subs are subs.
agent.5 said:
They seem very expensive for an 8" sub. I have a guy in New Orleans who is supposed to make 10" units that I designed for the same price. But, subs are subs.
Re: Re: subwoofer questions
Interesting. I think people on the group buy thread will want subs too.
gedlee said:
Interesting. I think people on the group buy thread will want subs too.
Hello,
I think the horn called "spherical" in Hornresp is better known as Kugellwellen and was first designed by Rösch at the Klangfilm Laboratories. Litterature about this horn is rare.
See:
H.Schmidt
"Über eine neue Lautsprecherkombination"
"Funk und Ton"
N°5, 1950, pp.226-232
The Kugelwellen'theory is based on sherical cap wavefronts all of them having a radius which is the double of the tractrix horn of the same cut-off frequency. The expansion of the area of the wavefronts is according to an exponential law.
What Hornresp doesn't show is that a Kugelwellen horn possess a profile that roll back at the mouth (see attached graph).
The Tractrix doesn't curve back because, near the mouth, the expansion of the theorical spherical cap wavefronts departs from the exponential law. I used to revisit the Tractrix profile according to an exponential expansion of the wavefront and in that case the profile of the "revisited tractrix" rolls back at the mouth (see attached file). Both the Tractrix, the Kugelwellen and the Tractrix revisited are based on "constant speed" translated spherical wavefronts along their axis and thus their "theorical wavefronts" or isophase surfaces are not parallel. This is a one of their negative features...
(but is the OS waveguide also based on non parallel wavefronts = isophase surface , or not, that's an interesting question...)
Note: on the attached file the Le Cléac'h horn was calculated using T = 1 (expansion of the area of the wavefronts according to an exponential law). You may see that the Kugelwellen and the T=1 Le Cléac'h horn posess a similar profile on more than 90% of their length.
Best regards from Paris, France.
Jean-Michel Le Cléac'h
I think the horn called "spherical" in Hornresp is better known as Kugellwellen and was first designed by Rösch at the Klangfilm Laboratories. Litterature about this horn is rare.
See:
H.Schmidt
"Über eine neue Lautsprecherkombination"
"Funk und Ton"
N°5, 1950, pp.226-232
The Kugelwellen'theory is based on sherical cap wavefronts all of them having a radius which is the double of the tractrix horn of the same cut-off frequency. The expansion of the area of the wavefronts is according to an exponential law.
What Hornresp doesn't show is that a Kugelwellen horn possess a profile that roll back at the mouth (see attached graph).
The Tractrix doesn't curve back because, near the mouth, the expansion of the theorical spherical cap wavefronts departs from the exponential law. I used to revisit the Tractrix profile according to an exponential expansion of the wavefront and in that case the profile of the "revisited tractrix" rolls back at the mouth (see attached file). Both the Tractrix, the Kugelwellen and the Tractrix revisited are based on "constant speed" translated spherical wavefronts along their axis and thus their "theorical wavefronts" or isophase surfaces are not parallel. This is a one of their negative features...
(but is the OS waveguide also based on non parallel wavefronts = isophase surface , or not, that's an interesting question...)
Note: on the attached file the Le Cléac'h horn was calculated using T = 1 (expansion of the area of the wavefronts according to an exponential law). You may see that the Kugelwellen and the T=1 Le Cléac'h horn posess a similar profile on more than 90% of their length.
Best regards from Paris, France.
Jean-Michel Le Cléac'h
David McBean said:
Attachments
Jmmlc said:
The OS contour is based on a solution to the full 3 dimensional wave equation. The wavefronts are, by definition, iso-phase, but that does not mean parallel in common understanding. They are parallel in the sense that they travel along and perpendicular to a set of orthogonal coordinates, which in a non-Euclidean geometry sense is the deffinition of parrallel.
The OS solutions are analytically exact in full three dimensions and as such they are the only true solution of the wave equation for a flared contour, all others being only approximations, some better than others.
Re: Re: Re: subwoofer questions
I won't be doing those so its not up to me.
Personnally those sizes are way overkill when you have multiple subs in a small room. The 18" works well - in clubs and auditorium where 120 dB at 30 Hz is desired, but size they are too big for one person to carry they are not very practicle.
For homes I prefer 10"s and 12"s.
agent.5 said:
I won't be doing those so its not up to me.
chrismercurio said:
Personnally those sizes are way overkill when you have multiple subs in a small room. The 18" works well - in clubs and auditorium where 120 dB at 30 Hz is desired, but size they are too big for one person to carry they are not very practicle.
For homes I prefer 10"s and 12"s.