I was just wondering if anybody uses sealed eq'd type subs below horn subs. I'm guessing a digital delay would help.
The reason I've never tried a horn sub is the higher cutoff of horn subs (I know thats a limitation of my rooms size, rather than horn subs btw
)
I'm thinking my 3 tempests below a pair of 30Hz horns could be very interesting, giving me the 15Hz extension that I get now, with better defined bass and more 'dynamics' in the lower mid stuff (40 - 80Hz)
At the moment my mains have 2x10" s-speaks per side, and they sound great flat to 20Hz at lower volumes. Crossing to the tempests at 40Hz, 24dB xo gives no loss of quality, but better extension, and allows dynamics at a higher volume. Crossing them to the tempests at 80HZ gives even better dynamics, but lower definition of bass. I'm thinking maybe a pair of horn subs to replace the s-speaks will give better dynamics/definition, and crossed to the tempests will still give me low bass I need
Any input is appreciated
Cheers,
Rob
The reason I've never tried a horn sub is the higher cutoff of horn subs (I know thats a limitation of my rooms size, rather than horn subs btw
)I'm thinking my 3 tempests below a pair of 30Hz horns could be very interesting, giving me the 15Hz extension that I get now, with better defined bass and more 'dynamics' in the lower mid stuff (40 - 80Hz)
At the moment my mains have 2x10" s-speaks per side, and they sound great flat to 20Hz at lower volumes. Crossing to the tempests at 40Hz, 24dB xo gives no loss of quality, but better extension, and allows dynamics at a higher volume. Crossing them to the tempests at 80HZ gives even better dynamics, but lower definition of bass. I'm thinking maybe a pair of horn subs to replace the s-speaks will give better dynamics/definition, and crossed to the tempests will still give me low bass I need
Any input is appreciated
Cheers,
Rob
Rob, looks like we're on the same page there. My feeling is with my AV12s that double bass in particular sounds just a little muffled/lacking definition in the upper bass range. This is true even with a calibrated perfectly flat response.
I'm curious to try dipole bass in that range, but it's not going to get the dynamics I want without being larger and more expensive than I can live with for now.
I've been considering a 40 Hz horn with a high excursion 8" like the Apex Jr / TB / MCM ... however these are cheapies and only likely to be more accurate due to the (compromised) horn loading. As I understand, the rear compression chamber equalises pressure on either side of the cone and in effect forces it to be more linear, while at the same time, increasing efficiency. Hence distortion is lower in two ways.
However, I wonder if a better approach is to start with a driver which has lower distortion in the first place. The koda 8" appears an excellent candidate with high xmax and fs, and its xbl2 motor, although it's likely hard to get hold of now
Just a thought. I wonder if you may have better options than the Lab subwoofer. Of course there is a good compromised horn design. Then on the other hand you miss the learning curve, and the chance to remove some compromises and make something better.
* compromise 1 - size - can you live with bigger?
* compromise 2 - driver - how about a driver that is more linear?
I believe horns are made small by doing things like using an 8" or 12" high excursion driver, but what if you started with a driver that is more linear in the first place? Say for example a number of horns based on the Eminence Magnum 12HO? It's the cheapest high efficiency driver I've seen that is designed for bass and has a shorting ring and it's very solidly built. I can get it for the price of a scan speak, yet I suspect it has the same quality ... just more quantity!
I had a play with hornresp last night, and I'm finding it's very easy to get a VERY BAD horn if things aren't quite right. Change a few numbers and instead of flat response to 40 Hz, you get the worst kind of response you can imagine, with huge sharp spikes and a very high F3. Hmmmmm, not as easy as I'd hoped!
I'm curious to try dipole bass in that range, but it's not going to get the dynamics I want without being larger and more expensive than I can live with for now.
I've been considering a 40 Hz horn with a high excursion 8" like the Apex Jr / TB / MCM ... however these are cheapies and only likely to be more accurate due to the (compromised) horn loading. As I understand, the rear compression chamber equalises pressure on either side of the cone and in effect forces it to be more linear, while at the same time, increasing efficiency. Hence distortion is lower in two ways.
However, I wonder if a better approach is to start with a driver which has lower distortion in the first place. The koda 8" appears an excellent candidate with high xmax and fs, and its xbl2 motor, although it's likely hard to get hold of now
Just a thought. I wonder if you may have better options than the Lab subwoofer. Of course there is a good compromised horn design. Then on the other hand you miss the learning curve, and the chance to remove some compromises and make something better.
* compromise 1 - size - can you live with bigger?
* compromise 2 - driver - how about a driver that is more linear?
I believe horns are made small by doing things like using an 8" or 12" high excursion driver, but what if you started with a driver that is more linear in the first place? Say for example a number of horns based on the Eminence Magnum 12HO? It's the cheapest high efficiency driver I've seen that is designed for bass and has a shorting ring and it's very solidly built. I can get it for the price of a scan speak, yet I suspect it has the same quality ... just more quantity!
I had a play with hornresp last night, and I'm finding it's very easy to get a VERY BAD horn if things aren't quite right. Change a few numbers and instead of flat response to 40 Hz, you get the worst kind of response you can imagine, with huge sharp spikes and a very high F3. Hmmmmm, not as easy as I'd hoped!
Thanks for you response Paul.
For me -personally- I am a lot happier building the labhorn as I honestly feel that I couldn't design a better basshorn than Tom Danley. Also the lab12 driver was designed to work in that enclosure. I doubt I'd be lucky enough to arrive at the exact right enclosure for a different driver.
Also, the cad files are available and I've already converted them for my system at work , and have the sides cut for 4 cabinets already....
In hindsight I reckon a pair of decent commercial servo subs 30 - 80Hz (Paradigm servo15 / velodyne dd-18 etc) would also give excellent results, though far more expensive, and a lot less output than the labs (and you'd still need the tempests etc underneath them)
As to the compromises, The size is huge with the labs anyhow, and I'll be using 2 stacked against my back wall, firing into the corner. The linearity of the drivers I doubt will ever be a compromise in home use. (esp with 2 units)
Your definition of double bass is spot on btw
Cheers,
Rob
For me -personally- I am a lot happier building the labhorn as I honestly feel that I couldn't design a better basshorn than Tom Danley. Also the lab12 driver was designed to work in that enclosure. I doubt I'd be lucky enough to arrive at the exact right enclosure for a different driver.
Also, the cad files are available and I've already converted them for my system at work
, and have the sides cut for 4 cabinets already.... In hindsight I reckon a pair of decent commercial servo subs 30 - 80Hz (Paradigm servo15 / velodyne dd-18 etc) would also give excellent results, though far more expensive, and a lot less output than the labs (and you'd still need the tempests etc underneath them)
As to the compromises, The size is huge with the labs anyhow, and I'll be using 2 stacked against my back wall, firing into the corner. The linearity of the drivers I doubt will ever be a compromise in home use. (esp with 2 units)
Your definition of double bass is spot on btw
Cheers,
Rob
I see your point, and it's a point that I've considered as well. Can us diyers design a better COMPROMISED horn? Probably not.
Can we do a better bass horn if in our situation we can remove some of the compromises? I think so. With less restrictions Tom Danley could do it better, but with some of the constraints he works with being removed, we have a chance at doing something better.
Granted, the labhorn is very big. It's bigger than I can live with for now. Let us know how it goes.
What do you plan to do about the response? ie. it's not very flat ...
I've seen a modified version of the lab horn which was used in a church. The folds were removed and it was built as a single horn which was built into the ceiling space. I still don't know much about horns, but I wonder if you could either make it into a shape that removes some folding (which might or might not make construction easier). I also wonder - someone might have made a version which removes some of the compromises.
What if, for example, you built a pair of single driver versions, with the same width and depth, but a much greater height. This would then fit in the same space in your room. Just a thought. There are so many of the labhorn out there, that there might already be a less compromised version you could copy that would still fit in your room. Just a thought.
Hi Paul,
If you lose some folds then you kind of end up with less but bigger folds if you get what I mean. ie 1 fold of the horn would have to be 180 degrees.... Apparently at the freq's these horns are designed for the wavelengths are too big to be affected by the folds anyhow.
I can't make them any higher as 2 stacked will be 1" off my ceiling!
The response will be similar to the plot for 4 cabs due to the wall reinforcement.
(I think..)
http://web1.prosoundweb.com/lsp/4shortlab-wfg-nd.jpg
I should also get some low end boost from room gain aswell (maybe cross at 25Hz ? )
Also I'll be using a dcx2496 to xo to the tempests so I'll have some parametric eq available, as well as the delays needed to make this work. (am planning on using a DEQ2496 aswell as the dcx so I'll have plenty of eq available)
The main advantage is that I don't have to try and work out all the folds to make the horn smooth through them..
Cheers,
Rob
If you lose some folds then you kind of end up with less but bigger folds if you get what I mean. ie 1 fold of the horn would have to be 180 degrees.... Apparently at the freq's these horns are designed for the wavelengths are too big to be affected by the folds anyhow.
I can't make them any higher as 2 stacked will be 1" off my ceiling!
The response will be similar to the plot for 4 cabs due to the wall reinforcement.
(I think..)
http://web1.prosoundweb.com/lsp/4shortlab-wfg-nd.jpg
I should also get some low end boost from room gain aswell (maybe cross at 25Hz ? )
Also I'll be using a dcx2496 to xo to the tempests so I'll have some parametric eq available, as well as the delays needed to make this work. (am planning on using a DEQ2496 aswell as the dcx so I'll have plenty of eq available)
The main advantage is that I don't have to try and work out all the folds to make the horn smooth through them..
Cheers,
Rob
Rob, you and I might sometime in the near future end up with a fairly similar system! I have ultracurve and plan to get ultradrive. I got out a tape measure and walked around the room to see where a lab horn might fit! That thing is HUGE! If I put one flat between my mains, there would not be much space between and it's not far from being a foot rest as well in that position!
I did some simulating in hornresponse last night and managed to get a similar looking response. There is a peak around 35 and 90 Hz. One thing I found is that as you make the throat area larger, the bottom peak becomes more pronounced. As you make it smaller, the peak flattens until it is completely eliminated. It does not seem to affect the rest of the response, although there is a small impact on cone excursion. I also found that adjusting the throat area and the volume of the rear chamber together is a good way to control the bottom end of the response.
The volume in the rear chamber, VRC has a big impact on excursion control and bottom end efficiency. Below fc, you then have a sealed box. So I started to think, what if the rear volume were increased? Another what if scenario I tried, was using my drivers with twice the excursion of the Lab12. With 70L total VRC, I was able to get 115db as I recall @ 20 Hz. Not bad since I can't normally get that in a sealed box!
This approach has a few downsides though. I think first is it may not be as linear over the horn range, since VRC is intended to force the driver to be more linear than it would in any other loading. Second, cone excursion increases rapidly below fc, yet there is no visual feedback to see when the driver is being pushed. Hence damage from overexcursion is possible, although this occurs when there is 135db above 40 Hz and 115db @ 20 Hz with just one of them.
One thing I notice about the Lab12 is that it's designed with a lot of excursion control. The very small VRC restricts excursion very effectively below fc. The axial length is about 3.6m, but it seems for a 40 Hz version you can make it about 3m with a slightly smaller mouth.
Still, this is just a newbie playing around with hornresp.
My (currently novice) opinion is that if you are going to drive it with less than 500w and use a highpass around fc, you might be better with some slight modifications to smooth the response a little for home use. I'd be very interested to hear from some more experienced horn guys on what they think of modifying the Lab12 for home use.
EDIT: not trying to get you to change your mind, just thinking out loud really ...
I did some simulating in hornresponse last night and managed to get a similar looking response. There is a peak around 35 and 90 Hz. One thing I found is that as you make the throat area larger, the bottom peak becomes more pronounced. As you make it smaller, the peak flattens until it is completely eliminated. It does not seem to affect the rest of the response, although there is a small impact on cone excursion. I also found that adjusting the throat area and the volume of the rear chamber together is a good way to control the bottom end of the response.
The volume in the rear chamber, VRC has a big impact on excursion control and bottom end efficiency. Below fc, you then have a sealed box. So I started to think, what if the rear volume were increased? Another what if scenario I tried, was using my drivers with twice the excursion of the Lab12. With 70L total VRC, I was able to get 115db as I recall @ 20 Hz. Not bad since I can't normally get that in a sealed box!
This approach has a few downsides though. I think first is it may not be as linear over the horn range, since VRC is intended to force the driver to be more linear than it would in any other loading. Second, cone excursion increases rapidly below fc, yet there is no visual feedback to see when the driver is being pushed. Hence damage from overexcursion is possible, although this occurs when there is 135db above 40 Hz and 115db @ 20 Hz with just one of them.
One thing I notice about the Lab12 is that it's designed with a lot of excursion control. The very small VRC restricts excursion very effectively below fc. The axial length is about 3.6m, but it seems for a 40 Hz version you can make it about 3m with a slightly smaller mouth.
Still, this is just a newbie playing around with hornresp.
My (currently novice) opinion is that if you are going to drive it with less than 500w and use a highpass around fc, you might be better with some slight modifications to smooth the response a little for home use. I'd be very interested to hear from some more experienced horn guys on what they think of modifying the Lab12 for home use.
EDIT: not trying to get you to change your mind, just thinking out loud really ...
Hi Paul,
""Rob, you and I might sometime in the near future end up with a fairly similar system!""
Reading some of your other posts I think you may be right...
I'm about to build a pair of Wayne Parhams midhorns to have a listen to aswell.. You don't seem to find many midhorn designs for the 300 - 1200 Hz range, which seems strange to me but I'm no horn expert..Is there something fundamentally wrong with this type of horn ?
http://www.audioroundtable.com/PiSpeakers/messages/14408.html
I liked the look of this implementation :
http://www.audioroundtable.com/PiSpeakers/messages/17117.html
I'm pretty sure you'll have seen the 'V.3 Labhorn' here :
http://www.geocities.com/hulkss/index.html
He has made some changes to try and smooth out the top end I believe... I think the horn extentions may come into the equation though.
Good luck with the horn building / how to web page btw - I think thats a great idea..
Cheers,
Rob
""Rob, you and I might sometime in the near future end up with a fairly similar system!""
Reading some of your other posts I think you may be right...
I'm about to build a pair of Wayne Parhams midhorns to have a listen to aswell.. You don't seem to find many midhorn designs for the 300 - 1200 Hz range, which seems strange to me but I'm no horn expert..Is there something fundamentally wrong with this type of horn ?
http://www.audioroundtable.com/PiSpeakers/messages/14408.html
I liked the look of this implementation :
http://www.audioroundtable.com/PiSpeakers/messages/17117.html
I'm pretty sure you'll have seen the 'V.3 Labhorn' here :
http://www.geocities.com/hulkss/index.html
He has made some changes to try and smooth out the top end I believe... I think the horn extentions may come into the equation though.
Good luck with the horn building / how to web page btw - I think thats a great idea..
Cheers,
Rob
Greets!
There's nothing fundamentally wrong with horn loading any BW, but why only two octaves unless it's strictly for bridging the efficiency gap between a compression driver and HE woofer system, such as Altec did with the A7, which only loads from ~175-337 Hz. Historically, a horn good to a 1200-1600 Hz XO point loaded to 80-100 Hz.
GM
There's nothing fundamentally wrong with horn loading any BW, but why only two octaves unless it's strictly for bridging the efficiency gap between a compression driver and HE woofer system, such as Altec did with the A7, which only loads from ~175-337 Hz. Historically, a horn good to a 1200-1600 Hz XO point loaded to 80-100 Hz.
GM
Rob, I came across something that might interest you. I found a waveguide design in a paper by Peavey. It discusses typical problems with existing horn lenses and gives a basis for a new design which overcomes the problems quite well. I'm not on my computer so don't have the link, but I posted it on the recent thread on waveguides. That is, if you feel inclined to do some more horn stuff! That waveguide appears similar in the idea to one designed by Earl Geddes which he claimed was rated as equal to a Gradient speaker in a blind test, reinforcing his argument that a CD with horn can sound as good as a hifi speaker if designed to avoid diffraction.
re midhorns
The problem with midrange horns is that if they are designed using the plane wave approximation relavent for bass horns you get significant errors due to the real wavefronts being curved.
The type of midrange horn that takes this into account is the tractrix, and it is probably its relative lack of modal propagation that gives it its reputation as the most natural and unhorn like sounding form of midrange horn.
The basic problem is that a tube is the only real waveguide for a plane wave, and a cone the only real waveguide for a spherical one, and the problem with a compression driver is to bend the plane wave it produces into a spherical one, Geddes shows the the optimum boundary shape for doing this is what he has called the "os waveguide".
The os waveguide has essentially a quadratic expansion rate like a conical conical horn, the differnce being that the parabola is symetrical about the y axis, which means that it has zero slope at its throat, the conical horn has a finite slope at its throat thus the wavefront should be a spherical cap at its throat rather than a plane wave. This is a chracteristic that dome radiators , (at least at the lower end of the frequency range in the case of soft domes), have, it is also approximately true for cone radiators. From this the midrange horn that is likely to produce the least modal propagation and "horny" sound is the conical one, listening tests bear this out.
If you use some form of throat compression phase plug etc. then the matter is complicated by the fact that getting an ideal flat or spherical cap wavefront is hard for diy people to do so such horns tend to suffer from excess reflection and diffraction, direct loading with no compression giving a better sounding result.
The problem with midrange horns is that if they are designed using the plane wave approximation relavent for bass horns you get significant errors due to the real wavefronts being curved.
The type of midrange horn that takes this into account is the tractrix, and it is probably its relative lack of modal propagation that gives it its reputation as the most natural and unhorn like sounding form of midrange horn.
The basic problem is that a tube is the only real waveguide for a plane wave, and a cone the only real waveguide for a spherical one, and the problem with a compression driver is to bend the plane wave it produces into a spherical one, Geddes shows the the optimum boundary shape for doing this is what he has called the "os waveguide".
The os waveguide has essentially a quadratic expansion rate like a conical conical horn, the differnce being that the parabola is symetrical about the y axis, which means that it has zero slope at its throat, the conical horn has a finite slope at its throat thus the wavefront should be a spherical cap at its throat rather than a plane wave. This is a chracteristic that dome radiators , (at least at the lower end of the frequency range in the case of soft domes), have, it is also approximately true for cone radiators. From this the midrange horn that is likely to produce the least modal propagation and "horny" sound is the conical one, listening tests bear this out.
If you use some form of throat compression phase plug etc. then the matter is complicated by the fact that getting an ideal flat or spherical cap wavefront is hard for diy people to do so such horns tend to suffer from excess reflection and diffraction, direct loading with no compression giving a better sounding result.
Re: re midhorns
Hi all
I probably should keep my mouth shut here,
I have to say up front that there's a lot about horns I don't know.
But I have a bit of practical experience of trying to get horns to sound good in the living room, so here goes:
And the problems with waves in horns is that as far as I know
they behave very chaotic, not matter what shape the horn...
IMHO the tractrix probably sounds good beacuse of relatively good mouth termination...
However, it is based on the assumtion that the waves have the same curvature through out the horn. Which they don't.
On the matter of conical horns , some people like them and some don't.
Personally I think conical horns suck.
They have a pretty "constant" coverage angle in their intended frequency area ( if done "right" , whatever that means...) and they are very easy to make.
I am sort of afraid that the latter is why they are so very popular right now. Apart from that I can't really say anything good about them.
If you intend to drive your horns with big transistor polluting machines by all means use conical horns, you won't hear the difference anyways
Be prepared to use a good amount of eq, tho.
I am going to shut up now....
cheers
Hi all
I probably should keep my mouth shut here,
I have to say up front that there's a lot about horns I don't know.
But I have a bit of practical experience of trying to get horns to sound good in the living room, so here goes:
And the problems with waves in horns is that as far as I know
they behave very chaotic, not matter what shape the horn...
IMHO the tractrix probably sounds good beacuse of relatively good mouth termination...
However, it is based on the assumtion that the waves have the same curvature through out the horn. Which they don't.
On the matter of conical horns , some people like them and some don't.
Personally I think conical horns suck.
They have a pretty "constant" coverage angle in their intended frequency area ( if done "right" , whatever that means...) and they are very easy to make.
I am sort of afraid that the latter is why they are so very popular right now. Apart from that I can't really say anything good about them.
If you intend to drive your horns with big transistor polluting machines by all means use conical horns, you won't hear the difference anyways
Be prepared to use a good amount of eq, tho.
I am going to shut up now....
cheers
re horns
I have a pair of conical horns with a flared mouth. These cover 300-3000 Hz. and I would recomend them as easy to make and sound good.
My previous post did not mention the research into midrange horns that shows that those that in double blind tests are described as such things as"quacky"and "nasal", all have common features , they have a lot of mouth reflection and they have discontinuities that cause diffraction, and they are longer than they need be.
These comments are when compared to direct radiators and other horns in the same tests.
The major difference between horns and direct radiators is that the radiation inside horns is dispersive, different frequencies travel at different velocities in more than one mode, this does not happen with direct radiators since free air is non dispersive and has only one mode.
The basic principle that Geddes, and other designers employ is that the less amount of reflection and diffraction there is the less modal propagation there is, the more like direct radiators the sound becomes. The low level of these effects is chracteristic of tractrix, conical and os type curves, note that the exponential horn at midrange frequencies has a high amount of these effects especially at the upper end, and thus a testing shows sounds hornlike.
I hope this helps
I have a pair of conical horns with a flared mouth. These cover 300-3000 Hz. and I would recomend them as easy to make and sound good.
My previous post did not mention the research into midrange horns that shows that those that in double blind tests are described as such things as"quacky"and "nasal", all have common features , they have a lot of mouth reflection and they have discontinuities that cause diffraction, and they are longer than they need be.
These comments are when compared to direct radiators and other horns in the same tests.
The major difference between horns and direct radiators is that the radiation inside horns is dispersive, different frequencies travel at different velocities in more than one mode, this does not happen with direct radiators since free air is non dispersive and has only one mode.
The basic principle that Geddes, and other designers employ is that the less amount of reflection and diffraction there is the less modal propagation there is, the more like direct radiators the sound becomes. The low level of these effects is chracteristic of tractrix, conical and os type curves, note that the exponential horn at midrange frequencies has a high amount of these effects especially at the upper end, and thus a testing shows sounds hornlike.
I hope this helps
Hi Rcw,
yes that does help-thanks.. The thing is my mids are 99dB/1W raw, and approximately 95dB/1W after I've eq'd them flat. They're crossed 24dB/oct at 300Hz and 1300Hz.
Do you think that trying a midhorn is worthwhile ? I get the spl's I need with them as is, and I was wondering whether horn loading would improve things.( mainly improvements from directivity - less room modes ? ) If it helps my tweeters are 1"CD beyma 380's on a 90x40 horn, and my bass units are sealed 15" beyma lx60's running 80 Hz - 300Hz .
I was going to build the pi midhorns just so I could hear what a midhorn sounds like. I'm actually pleased with my speakers 'as is'
But am 'horn curious' As I'm not too good with horn design a plan to copy is of benefit to me. ie I'd rather listen to a proven design rather than try and design something myself.
Thats the weird thing about horn speakers..
Everybody knows what a 2-way box sounds like, and sealed subs/ vented subs.., and most people have heard dipoles at some point, but most people don't get to hear horns unless they buy them/ build them blind....
Cheers,
Rob.
yes that does help-thanks.. The thing is my mids are 99dB/1W raw, and approximately 95dB/1W after I've eq'd them flat. They're crossed 24dB/oct at 300Hz and 1300Hz.
Do you think that trying a midhorn is worthwhile ? I get the spl's I need with them as is, and I was wondering whether horn loading would improve things.( mainly improvements from directivity - less room modes ? ) If it helps my tweeters are 1"CD beyma 380's on a 90x40 horn, and my bass units are sealed 15" beyma lx60's running 80 Hz - 300Hz .
I was going to build the pi midhorns just so I could hear what a midhorn sounds like. I'm actually pleased with my speakers 'as is'
But am 'horn curious'
As I'm not too good with horn design a plan to copy is of benefit to me. ie I'd rather listen to a proven design rather than try and design something myself.Thats the weird thing about horn speakers..
Everybody knows what a 2-way box sounds like, and sealed subs/ vented subs.., and most people have heard dipoles at some point, but most people don't get to hear horns unless they buy them/ build them blind....
Cheers,
Rob.
re midhorns
The thing about the conical type of horn Rob that it is a constant directivity device. This means that over a particular frequency range it is possible to get a flat frequency and power responce. Another thing about the conical horn is that it is not flat on axis and needs to be fed from a first order high pass filter. This latter feature results in a dramatic increase in power handling especially at the lower end of the range, my horns have a total of 15db. attenuation at 300Hz. and an overall efficiency increase of 4db. This gives an overall 19db. increase in the excursion limited power handling at plower frequencies where its needed, and at all domestic levels the distortion is dramatically reduced and the sound effortless, the Genelec range of monitoring speakers have exploited this for some years, and much of the music and film sountracks we hear are produced on these.
Ther is a larger debate about the need for constant directivity, Floyd Toole, a much respected academic researcher before he joined Harman international, has extensive discussion about this on the Infinity site, as does Earl Geddes on his site.
The thing about the conical type of horn Rob that it is a constant directivity device. This means that over a particular frequency range it is possible to get a flat frequency and power responce. Another thing about the conical horn is that it is not flat on axis and needs to be fed from a first order high pass filter. This latter feature results in a dramatic increase in power handling especially at the lower end of the range, my horns have a total of 15db. attenuation at 300Hz. and an overall efficiency increase of 4db. This gives an overall 19db. increase in the excursion limited power handling at plower frequencies where its needed, and at all domestic levels the distortion is dramatically reduced and the sound effortless, the Genelec range of monitoring speakers have exploited this for some years, and much of the music and film sountracks we hear are produced on these.
Ther is a larger debate about the need for constant directivity, Floyd Toole, a much respected academic researcher before he joined Harman international, has extensive discussion about this on the Infinity site, as does Earl Geddes on his site.
Paul : Your on the right track,except you cant make the a horn better than the labhorn,it can only be different. There is no wasted space. You could use a notch filter or high Q parametric equaliser to prevent driver damage.
Use a higher BL driver for less crazy excursion below cutoff.Not having a rear chamber changes things,stops that excursion peak while allowing assymetrical output to occur.(bassmaxx)But since the distortion is 'happy 2HD',no worries.I think our ears might even mask it(cheever_thesis.pdf)
Labhorn v3 top end improvements : vocals sound funny coming through folded horns so there isnt much point to this improvement,but the adjustments do allow a more flat midband response when not using 4-8.
http://www.dbkeele.com/papers.htm
http://www.dbkeele.com/PDF/Keele (1975-05%20AES%20Preprint)%20-%20Whats%20So%20Sacred%20Exp%20Horns.pdf
Use a higher BL driver for less crazy excursion below cutoff.Not having a rear chamber changes things,stops that excursion peak while allowing assymetrical output to occur.(bassmaxx)But since the distortion is 'happy 2HD',no worries.I think our ears might even mask it(cheever_thesis.pdf)
Labhorn v3 top end improvements : vocals sound funny coming through folded horns so there isnt much point to this improvement,but the adjustments do allow a more flat midband response when not using 4-8.
http://www.dbkeele.com/papers.htm
http://www.dbkeele.com/PDF/Keele (1975-05%20AES%20Preprint)%20-%20Whats%20So%20Sacred%20Exp%20Horns.pdf
Re: re midhorns
Do you have any more info on why the conical would have this caracteristic? Is this also the case with higher BL drivers?
This brings me to another thing ive never understood, what is the upper frequency limit of a horn? Ive read things like 3-4 octaves higher than fc. Is this a result of the higer frequencies being swallowed bij the lower frequencies because of diffraction?
but what about the Oris horn with a full range driver?
Its not a real horn but more like a waveguide because its so short so thats probably the reason.
Greets, Collin
rcw said:
Do you have any more info on why the conical would have this caracteristic? Is this also the case with higher BL drivers?
This brings me to another thing ive never understood, what is the upper frequency limit of a horn? Ive read things like 3-4 octaves higher than fc. Is this a result of the higer frequencies being swallowed bij the lower frequencies because of diffraction?
but what about the Oris horn with a full range driver?
Its not a real horn but more like a waveguide because its so short so thats probably the reason.
Greets, Collin
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