It is?? How come?
It does over 130 dB/m at full power with an f3 around 50 Hz (2 pi) measured. How does that not make it a bass horn? I wouldn't call it a sub, but bass horn definately.
A 1/4 wavelength horn is a very common approach and with 7', 4" it does approach 1/4 wavelength of 40 Hz. It might not have the moutharea tot get 40 Hz but than again it wasn't designed to.
According to some of the information above the Labhorn isn't a basshorn either. Not to mention there are no basshorns in PA systems.
With kind regards Johan
Rademakers said:
You can use any size horn you want, but to get anywhere near the efficiency it's capable of requires specific sizes - a smallish horn (like the one suggested) isn't anywhere near big enough to be considered a 'real' horn at bass frequencies. Why not just use a folded horn?, which gives a similar performance to the small horn, but in a more sensible size?.
Interesting site here, which says
"You will find that the length of a horn, especially a bass horn, quickly gets long and the mouth gets very large as you lower the Fo. If designing a bass horn, you might want to shorten it so the horn is a more manageable size. One acceptable method is to use a quarter wavelength of the fc as the minimum length. For throat = 70 cm2, fc=35 Hz, size factor = 4, this results in a horn length of 232 cm and mouth area of 1422 cm2, a reduction in length of 60% (possibly a bit too much shortening for really good sound)."
I mentioned that previously, it's because they would be far too big.
Real horns in real acoustical environments doesn't match too well the mouth area and lenght theory employed for designing things such as free space standing midrange horns.
Also, below the lowest resonance mode of a low frequency horn, driver loading vanishes quite progressively to direct radiation, so it's not easy at all to tell where horn loading ends and where plain "outer air" loading begins for the driver. In comparison with plain direct radiation, a driver front loaded with a horn will still show reduced cone displacement well below the lowest horn resonance mode.
Also, when several low frequency horns are placed together (or when a single one is corner loaded), their resonance modes may be shifted downwards by half an octave or more due to mutual coupling, and the residual loading effect below the lowest mode will become more remarkable, that's why "compact" low frequency horns must be used in groups for proper performance.
Obviously, these phenomena are not likely to be observed with the classic 150Hz huge tracktricx midrange horns that most people sem to build here.
Also, below the lowest resonance mode of a low frequency horn, driver loading vanishes quite progressively to direct radiation, so it's not easy at all to tell where horn loading ends and where plain "outer air" loading begins for the driver. In comparison with plain direct radiation, a driver front loaded with a horn will still show reduced cone displacement well below the lowest horn resonance mode.
Also, when several low frequency horns are placed together (or when a single one is corner loaded), their resonance modes may be shifted downwards by half an octave or more due to mutual coupling, and the residual loading effect below the lowest mode will become more remarkable, that's why "compact" low frequency horns must be used in groups for proper performance.
Obviously, these phenomena are not likely to be observed with the classic 150Hz huge tracktricx midrange horns that most people sem to build here.
It is folded.
The usual method is to design a bass horn that consists of several smaller horns that combine like it is one when stacked. Most calculations found other than simulations seem to concentrate on 4 pi radiation which isn't too practical and is taking hornsize out of correlation with practical use.
If a Lab isn't a bass horn than what would you call it? And what source do you use for your definition of a basshorn as well what is your definition of a bass horn?
I'm just a bit suprised as this is the first time in 3 years I've seen this definition of yours, while I'm quite active on the subject.
Wit kind regards Johan
Rademakers said:
Sorry, I hadn't noticed he'd now changed to accepting a folded horn?.
As I see it a horn and a folded horn are very different things, a folded horn being a 'bodge' to try and reduce a horn to manageable proportions.
Sorry
but if someone asks for a 'horn', I consider that's what it means, not downsized, and not folded.
Sorry
A dog is a dog, a folded dog is a dog, a downsized/ small dog is a dog.
A horn is basically an acoustic transformer, a folded horn is basically an acoustic transformer, a downsized folded horn is basically an acoustic transformer.
It seems to come down to taste-opinion rather than science. Which is fine by me but perhaps makes things unneccesary complicated?
Low frequencies are very forgiving to both folds and obstacles relatively small to the frequencies wavelength.
If you consider the Punisher you will see that the angle of the folds decreases as the speed of the air increases. The high pressure/ low speed movement allows for much tighter folds compared to the product of the acoustical transformation.
From 80 - 150 Hz folds become more difficult to overcome soundwise but for instance Funktion One uses folded horns up to 450 Hz (in combination with a phaseplug).
(no dogs where hurt during the making of this message)
Quarter wavelength horns do make use of 1/4-wavelength resonance, just like TL's. This increases output around frequencies with a 1/4 wavelength of the horn axial length.
In my personal view, transmission lines are similair to 'horns'. The lack of moutharea partially explains the relatively low sensitivity as it mostly relies on 1/4 wavelength resonance and due to lower sensitivity also more on the direct radiator output.
Both types can be simulated with similair or the same software (at least mine are). With a volume of 450 ltr and tuned at 33 Hz they're very suited for drum and bass
With kind regards Johan
myhrrhleine said:
There is "truth" and then there is FACT. (..and its amazing how often people think that they are the same thing when they may not be, and likely will not be. Note that "truth" in its most analagous form to fact, describes a state approaching fact to some degree.)
Remember what is a "truth" to you may not be a "truth" to another. Here we have had differening "truths" on just what represents bass, and on what a horn is. .. and obviously from the responses you are not alone in this.
I personally don't have a problem with someone's "truth" as long as long as they DEFINE what that "truth" is. Without it, communication is half-@ssed at best.
So myhrrhleine, IF your going to be pessimistically argumentative, then please describe the basis for your "truth".
For instance WHY does bob123 need a horn length "at least 10 meters long"? Note that he HAS given his intended use - instrument reinforecment principally 50 Hz up, but sometimes extending to 40 Hz. (..and note that he never said the response had to be flat to 40 Hz or lower.) Further, WHY is "10 meters short for a decent horn at 40 Hz"? In general WHY is "2-3 times" the wavelength best? More importantly, would it be "best" for his application (..and remember that instrument reinforcement implies portability). Consider that he isn't looking for the "absolute sound", but rather acceptable-to-good performance for his intended use.
(..I'll skip the part about path length, driver size, and oh.. little things like expansion profile and termination sd, as well as driver paramaters.)
And are the punisher horns really providing an increase in spl at 40 Hz? If you are that interested, why not determine the enclosed volume, (or even make a guess at it), of the punisher horn and then input that into any decent modeling program to determine the response at 40 Hz? (..and obviously then comparing the spl's between the horn and the sealed design.)
As seems often to be the case with longer threads.. people get a little side-tracked with the intended purpose of the thread.
The thread is NOT about:
1. What describes the passband under the term "Bass" generally.
2. What is theoretically the most effective method for horn loading.
What this thread IS about:
3. Horn loading, ( generally providing some additional gain through a more efficent air impeadance transfer), a driver for most of its INTENDED bandwith.
4. Via the overall design, providing the ability to achieve spl's approaching 130 db for most of the operating bandwidth.
5. Using #3 for reinforcing the sound of musical instruments that will be played PRINCIPALLY within that bandwidth.
6. #5 Neccesarily implies the additonal constraint of portability.. i.e. that its size and weight is something that can reasonably be transported by the user.
IMO - IF you are going to "quibble" about the punisher here, it would NOT be about either #1 or #2, rather it would be specifically over #4. That is, "will the bandwith of the punisher be enough for bob123's INTENDED application?"
I could certainly see some times when extension vs. spl will not be enough - I'm just not sure how often that will occur. Moreover this is not limited to low freq. extension, but also higher freq. extension. I could actually see more problems occuring (without eq. compensation - and even with it above 1kHz), with the upper freq. response. In particular bass guitars can be played pretty "high-up" at level. Without eq. the punisher may not be appropriate to his application. Again though, I don't know - and that is something he will have to figure out for himself.. (which is why I added the caveat of: "if it meets your needs").
How much efficiency, if any, do TL's generally add?
Bob could build a large folded TL, one of my fav bass loading methods. One can build it with either a small closed end to wide open end which I guess would give more efficiency, or a wider closed end to small open end which would give a shorter and more portable TL. For Hi-Fi large closed to small open ended TL's seem to be favoured but maybe that is because max SPL is not the main factor of design.
Bob, have you had a look at the sort of thing Meyer Sound, Turbo Sound and ElectroVoice implement for bass? These guys really know what they are doing. Something like a pair of MeyerSound M2D subs would not do bad at all. If used outside you could do well to implement some sound-steering using other subs to stop the sound being wasted in directions no-one wants it. Of course this adds about twice the expense. A program by electrovoice called ArrayShow is useful for helping set-up of PA subs.
Bob could build a large folded TL, one of my fav bass loading methods. One can build it with either a small closed end to wide open end which I guess would give more efficiency, or a wider closed end to small open end which would give a shorter and more portable TL. For Hi-Fi large closed to small open ended TL's seem to be favoured but maybe that is because max SPL is not the main factor of design.
Bob, have you had a look at the sort of thing Meyer Sound, Turbo Sound and ElectroVoice implement for bass? These guys really know what they are doing. Something like a pair of MeyerSound M2D subs would not do bad at all. If used outside you could do well to implement some sound-steering using other subs to stop the sound being wasted in directions no-one wants it. Of course this adds about twice the expense. A program by electrovoice called ArrayShow is useful for helping set-up of PA subs.
Tenson said:
That's a very bad choice. These designs are intended to achieve the lowest weight and truck space usage at the expense of performance and efficiency. They are also intended to be used in groups of a dozen or so (they rely on mutual loading, not on horn loading) If you take a single one, you have just a plain reflex "sub" (rolling off below 50Hz if not placed in groups) on a heavy duty enclosure intended for touring, but without anything else special on it.
Exactly, small, light and loud. A couple (okay maybe 4) of them would give a pretty decent amount of bass. I know its not horn loading but maybe bob doesn't know what’s best for him As people have already said, there is a reason not many people use horns for bass. Maybe because a number of these things will give equal SPL without being one single big *** lump to lug around.
As people have already said, there is a reason not many people use horns for bass. Maybe because a number of these things will give equal SPL without being one single big *** lump to lug around.
That's because the definition of bass horn seems to be different, yet I've not seen any source for that definition.
If a Punisher is a folded horn (or whatever) than thousands of people use folded horns (or whatever). It's one of the mainstreams in PA for larger crowds. There are perhaps more than a hundred designs, with the Punisher just being one of them. A newer design that made a good start.
Yes, 10 mtr long straigth bass horns on the other hand are not used by many for PA, I think we can all understand why.
I've used these two 18" TL's for PA, they do a good job in the livingroom as well.
They are similair in sensitivity to normal 18" basreflex with approximatly 96 dB/W/m (a piece). They're big, 60-75 kg and eat power like it's candy, when common reflex stop they do keep going. They're most excellent for d&b and alike. I could make them weight 40 kg (incluiding speaker) but they would still be to big with 450 -500 liter each, so difficult to handle and transport.
So I'm going to go with 4 x the small 18" basreflex you see on the first picture (round one's). Tuned low enough to favor a 30 Hz lowcut. It's the thing I would advise Bob123 to do as well (18" basreflex).
Punishers are nice but for d&b take multiples or 18" basreflex.
With kind regards Johan
A design that may meet you demands is the EV TL-4025. It is a double-folded hyperbolic horn with one 15" driver. Be aware that it would be around 80 kg a piece (using plywood) and measuring around 45x78x176 cm. You would have to use at least three of them stacked to get reasonable output at 40 Hz.
I have the building plans for that one if you are interested.
It is kind of a dinosaur back from the time when BASS HORNS were not only USED for PA but the STANDARD (might be the contrary of someone else's opinion).
Regards
Charles
I have the building plans for that one if you are interested.
It is kind of a dinosaur back from the time when BASS HORNS were not only USED for PA but the STANDARD (might be the contrary of someone else's opinion).
Regards
Charles
167cm is a bit to big for me, i would say i would go as big as 1M.
I may just stick some more sensitive drivers in my bass reflex sub (or build another). At the moment it is kicking out about 120db down to 40hz with 2 x 93db/w/m bass drivers (very cheap drivers).
A horn would be good but if i need 4 of them it would be very costly! Realy i would only like to build one more speaker as my setup would be to big to transport.
I am looking for big bass at a low cost. It does not have to go down to low just have a high spl.
What is the typical gain of a sonotube TL?
I may just stick some more sensitive drivers in my bass reflex sub (or build another). At the moment it is kicking out about 120db down to 40hz with 2 x 93db/w/m bass drivers (very cheap drivers).
A horn would be good but if i need 4 of them it would be very costly! Realy i would only like to build one more speaker as my setup would be to big to transport.
I am looking for big bass at a low cost. It does not have to go down to low just have a high spl.
What is the typical gain of a sonotube TL?
Look, if you want to make a lot of noise down to 35Hz a bandpass akin to the speakerplans.com X1 enclosure is your friend. Any decent PA woofer (4" coil) will handle the output of the 1kW amplifier if you're not feeding it sine-waves and operating it properly.
The punisher is very, very capable for a 50Hz+ design and some have been using it to a touch above 100Hz even. For home use put it in a corner with an extender and you'll raise hell. The X1 will raise hell as well and outperform a similar sized bass-reflex enclusure under power.
The punisher is very, very capable for a 50Hz+ design and some have been using it to a touch above 100Hz even. For home use put it in a corner with an extender and you'll raise hell. The X1 will raise hell as well and outperform a similar sized bass-reflex enclusure under power.
This should be enough for a guesstimation of what it is capable of doing. EV recommended to use at least three of them stacked. You can see that the length of the horn is 2m approx. There was also a "brother" of this one available called the "Jumbo Bass Box" which used 2x12" instead of one 15" driver.
If you want the complete plans e-mail me since I am hesitant to put these here.
I used to have two of these and I was quite content with their performance.
Regards
Charles
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