Hey all, first post.
I've been recently fascinated with back loaded horns. The look em is just awesome. I'd really love to get into making some of my own. But I feel like I'm getting swamped with information. I've found a few articles on them, and I've tried to digest what's been said in some of the threads here, but in the end I always end up scratching my head.
So, where would be a good place to start? Do I need to know a ton about other speaker cabinet styles before I can really get into back loaded horns?
I'm very new to speaker building, having some fun building cabinets for Leslie speakers, and I'd really love to be able to design my own speaker cabinets.
Thanks!
I've been recently fascinated with back loaded horns. The look em is just awesome. I'd really love to get into making some of my own. But I feel like I'm getting swamped with information. I've found a few articles on them, and I've tried to digest what's been said in some of the threads here, but in the end I always end up scratching my head.
So, where would be a good place to start? Do I need to know a ton about other speaker cabinet styles before I can really get into back loaded horns?
I'm very new to speaker building, having some fun building cabinets for Leslie speakers, and I'd really love to be able to design my own speaker cabinets.
Thanks!
BLH
Hello,
look my HP.
here a simple guide line for construction:
Calculation of expo horns
If you have AH, AM, l,
k still lacks the flare rate:
ln (AM / AH) / l = k
so you can see the surface
each point out (Al):
INV ln (l * k) * AH = Al
l m, AH + AM + AL in square meters
By Al e.g. m in width and divide
you have the distance in meters
AH = Horn throat
AM = Horn mouth
k = flare rate
l = length
Lengths and flare rate VALUES
K VALUES:
0.37 ~ 10 Hz
0.55 ~ 15 Hz
0.7 ~ 19 Hz
0.9 ~ 25 Hz
1.1 ~ 30 Hz
1.3 ~ 35 Hz
1.48 ~ 40 Hz
About an octave above k plays the horn,
if the length matches. At BL horn lengths
over 3.4 m, you get a suck out
below 100 Hz
4/lamda lengths VALUES
3.4 m ~ 25 Hz
2.8 m ~ 30 Hz
2.4 m ~ 35 Hz
2.1 m ~ 40 Hz
1.7 m ~ 50 Hz
1.4 m ~ 60 Hz
Most of my horns open
the last~ 75 cm (look ALPHORN)
with a double or triple k,
to get a better mouth+room
crossover.
Hello,
look my HP.
here a simple guide line for construction:
Calculation of expo horns
If you have AH, AM, l,
k still lacks the flare rate:
ln (AM / AH) / l = k
so you can see the surface
each point out (Al):
INV ln (l * k) * AH = Al
l m, AH + AM + AL in square meters
By Al e.g. m in width and divide
you have the distance in meters
AH = Horn throat
AM = Horn mouth
k = flare rate
l = length
Lengths and flare rate VALUES
K VALUES:
0.37 ~ 10 Hz
0.55 ~ 15 Hz
0.7 ~ 19 Hz
0.9 ~ 25 Hz
1.1 ~ 30 Hz
1.3 ~ 35 Hz
1.48 ~ 40 Hz
About an octave above k plays the horn,
if the length matches. At BL horn lengths
over 3.4 m, you get a suck out
below 100 Hz
4/lamda lengths VALUES
3.4 m ~ 25 Hz
2.8 m ~ 30 Hz
2.4 m ~ 35 Hz
2.1 m ~ 40 Hz
1.7 m ~ 50 Hz
1.4 m ~ 60 Hz
Most of my horns open
the last~ 75 cm (look ALPHORN)
with a double or triple k,
to get a better mouth+room
crossover.
Attachments
Looks interesting, but will it run on a Mac? I've really got to get Windows/BootCamp installed and running on my computer, but at the moment I don't have access to any Windows computers.
Hello,
AH= horn beginning
AM= horn end
AL= the length which you need for construction,
folding etc.
Hiifi horns are allways to small and short so you get dips and peaks.
look the impedanz of horns, if someone published it like me.
If you don´t know what an oktave is, read before building
AH= horn beginning
AM= horn end
AL= the length which you need for construction,
folding etc.
Hiifi horns are allways to small and short so you get dips and peaks.
look the impedanz of horns, if someone published it like me.
If you don´t know what an oktave is, read before building
Attachments
Last edited:
Hi GM,
AJ Horn is definitely simpler for me for BLH. Once the driver params are in the "library," you just specify rear-loaded, coupling chamber, mouth, length and throat. No summing of curves, and some of the geometry features are assumed (e.g., that you're building a "flat" constant-width cabinet).
So for me, the handy feature I need is that it generates a simple build-plan for the horn, in the form of a list of numbers (you enter the cabinet depth and it gives you the "width" along the curve plus cross-sectional area).
It does seem to model fewer factors (for example, baffle step does not appear to be modelled, and it appears to assume the driver and mouth are a point-source, i.e., not taking into account the offset between them into the summation -- but I am using version 5, and there is a version 6 with more features, and anyway, I could still be wrong about version 5).
I started using it in part because the Replikon guys were (and it seems, most German horn hobbyists). I haven't given HornResp a fair shake but will be doing so in the coming year.
Oops, I stand corrected -- it does account for the differing distance of driver vs. mouth to listening position. From the manual:
dL = distance(listener, horn mouth) - distance(listener, cone)
dL = distance(listener, horn mouth) - distance(listener, cone)
Hi GM,
Picture attached -- I just hammered in some random values. The cab is assumed to have height ("h", here 100cm) and depth ("b", here 20cm). Obviously that's handy if you're planning a non-round, constant-width box-type cab.
Then you choose Extras > List contour and it gives numbers for the curve.
Rather than flatten out the first big dip, for one project, I've been trying to place it around the ~80Hz floor-to-ceiling room mode.
(OT but right now I'm listening to some 1968 LaScalas and they are incredibly dynamic on orchestral. Astonishing, really.)
Picture attached -- I just hammered in some random values. The cab is assumed to have height ("h", here 100cm) and depth ("b", here 20cm). Obviously that's handy if you're planning a non-round, constant-width box-type cab.
Then you choose Extras > List contour and it gives numbers for the curve.
Rather than flatten out the first big dip, for one project, I've been trying to place it around the ~80Hz floor-to-ceiling room mode.
(OT but right now I'm listening to some 1968 LaScalas and they are incredibly dynamic on orchestral. Astonishing, really.)
Attachments
Hello,
l = meter
AL = area in sqm at the wished point l. INV ln (l*k)*AH=Al
k = 4pi * frequenz / c
c ~ 340, pi ~3,14
l = meter
AL = area in sqm at the wished point l. INV ln (l*k)*AH=Al
k = 4pi * frequenz / c
c ~ 340, pi ~3,14
Well, I know hm is trying to be helpful but perhaps the OP should read this first and maybe the valuable but cryptic replies will make more sense.
http://www.quarter-wave.com/Horns/Back_Horn.pdf
BTW, no matter what you may read torea, BLH design is well defined from a modelling point of view, but there is little consensus on what the design targets or overarching design philosophy should be. There is no substitute for getting Hornresp, spending 1,000 hours learning how to use it well (time well spent) and doing it yourself.
The MJK worksheets are also a Gold Plated investment if BLH's figure in your future.
http://www.quarter-wave.com/Horns/Back_Horn.pdf
BTW, no matter what you may read torea, BLH design is well defined from a modelling point of view, but there is little consensus on what the design targets or overarching design philosophy should be. There is no substitute for getting Hornresp, spending 1,000 hours learning how to use it well (time well spent) and doing it yourself.
The MJK worksheets are also a Gold Plated investment if BLH's figure in your future.
blakksheaudio,
i don´t agree, most simu programms are overload in theore, you don´t need
most information, but a simu is only a simu, real building and measurements are another
story and to construct a simulated horn to built it is a point where most people give up.
i don´t agree, most simu programms are overload in theore, you don´t need
most information, but a simu is only a simu, real building and measurements are another
story and to construct a simulated horn to built it is a point where most people give up.
hm,
I agree that there is no real substitute for building 'em and building 'em again. I have binned and burnt more prototypes than I care to remember.
Not everybody wants to do the long run though. An understanding of what is and is not possible, and a solid feel for prior art and the current state of the art can save a novice from disappointment and disillusionment.
As a designer also new to BLH design, I have found little trustworthy design theory on the web or, frankly, in this forum. There are a handful of sources that inspire with well thought out theory AND practice. There are also those that present only half the story, and only half true, and the novice has to wade through mountains of this crap to find the nuggets of truth concealed therein.
I have a very old speaker building book which discusses cabinet design mainly as a function of driver size. You know, 'A 12 inch driver needs a xxx cubic foot box, or yyy if an AxB hole is cut in the front panel'. Thiele and Small put that to the sword years ago. Martin King and many others have similarly laid bare the 'mysteries' of horn design. AJHorn, the MJK worksheets and Hornresp allow us to model, play with and understand what was previously 'black magic' and 'acquired knowledge'. What do you want the OP to do? Follow a few rough rules of thumb? Your information is extremely valuable, and no doubt hard won, and after a few simulations and experiments the OP will be able to do a lot with it. But unless you are going to design the horns for him he NEEDS to understand WTF is going on and MJK's articles are the best place for him to start.
Aaaahhhh, that feels better......
Hello,
i see you didn´t read my guide line, if someone want to construct
a horn, you need the info, a simulation doesn´t help,
it shows only if it would make sence.
I miss the info of the imp of an horn: the real and blind part.
T/S parameter are only for the driver resonance important, some people think
for the whole driver data.
the flare rate constant you don´t find in some simulation programms, but it
is much important for the bass.
If you have so much experience, where is something not to understand
in my guide line?
i see you didn´t read my guide line, if someone want to construct
a horn, you need the info, a simulation doesn´t help,
it shows only if it would make sence.
I miss the info of the imp of an horn: the real and blind part.
T/S parameter are only for the driver resonance important, some people think
for the whole driver data.
the flare rate constant you don´t find in some simulation programms, but it
is much important for the bass.
If you have so much experience, where is something not to understand
in my guide line?
Attachments
Last edited:
Well, as I said, I am new to BLH design. I have never designed one before, despite having designed and built dozens of other enclosures of many types, and done my fair share of research.
I see that you are an expert in horn design and I have respect for that.
I do not believe that the information in your guideline is sufficient to permit the OP to understand, or build, a BLH. If he seeks understanding he would do well to read the MJK articles. They are not the only, maybe not even the best, source of information but I found them useful and reliable when I was learning about horns. If the OP seeks only to build a BLH then he would be well advised to construct a proven project, perhaps even one of yours.
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