Hello, may the grace encourage uss here 
People around here might qualify me by looking at my last non-recent thread about an oversized loudspeaker box I built, but that wasn't really useless since I can make it a sealed box and grant sound quality for betters (forgive my english). So, recently I have understood the last stuff about loudspeaker efficiency, how it diffracts sound waves produced claiming the need for a box and horns for impedance match. Okay, so, as literature says, the impedance of air goes mismatched as speaker cone area decreases, but can be brought to balance by the artifice of a properly designed horn. Horns for bass are generally very wide and long (1.7 meters for a 200Hz cutoff frequency), and thats not much of a problem wasn't for the fact you probably won't have a single speaker with the demanded wattage for fitting in that box, so as if you want a very high power system (for example 10,000W) you would probably be dealing with at least 4+ speakers, if you manage to find 2,5kW versions of what you want. The mystic stuff comes forth when Its seems not likely that you can draw sketches of how sound will bouce around a multi channeled horn much like the exhaust gasses of a car goes into a single pipe. The question is: given the the properly ideal horn design for a given cutoff frequency (lenght of horn, width of mouth) can still have the same lenght and width as, for example, four 15" speakers each having a separated fold which goes into the main principal horn section?
I can actually do some trials, as I have here 54 working speakers of the sort of 5", 6.5" and 6x9, which are all assembled in a "wall like boxing", and supposedly they could sum up to the equivalent area of a 70 inch single loudspeaker cone. This large area woul contribute matching the impedance of air at low frequencys, but I dont know exactly if a many-speaker assembly just works right like this in the equivalent cone surface thing.
Hope you guys understand. I can get data and pictures but running all my equipment for these tests would be too much time intensive unless everyone here gets the thing pissed out of it!
Thank, thank you very much, until then,
See ya
Bern
People around here might qualify me by looking at my last non-recent thread about an oversized loudspeaker box I built, but that wasn't really useless since I can make it a sealed box and grant sound quality for betters (forgive my english). So, recently I have understood the last stuff about loudspeaker efficiency, how it diffracts sound waves produced claiming the need for a box and horns for impedance match. Okay, so, as literature says, the impedance of air goes mismatched as speaker cone area decreases, but can be brought to balance by the artifice of a properly designed horn. Horns for bass are generally very wide and long (1.7 meters for a 200Hz cutoff frequency), and thats not much of a problem wasn't for the fact you probably won't have a single speaker with the demanded wattage for fitting in that box, so as if you want a very high power system (for example 10,000W) you would probably be dealing with at least 4+ speakers, if you manage to find 2,5kW versions of what you want. The mystic stuff comes forth when Its seems not likely that you can draw sketches of how sound will bouce around a multi channeled horn much like the exhaust gasses of a car goes into a single pipe. The question is: given the the properly ideal horn design for a given cutoff frequency (lenght of horn, width of mouth) can still have the same lenght and width as, for example, four 15" speakers each having a separated fold which goes into the main principal horn section?
I can actually do some trials, as I have here 54 working speakers of the sort of 5", 6.5" and 6x9, which are all assembled in a "wall like boxing", and supposedly they could sum up to the equivalent area of a 70 inch single loudspeaker cone. This large area woul contribute matching the impedance of air at low frequencys, but I dont know exactly if a many-speaker assembly just works right like this in the equivalent cone surface thing.
Hope you guys understand. I can get data and pictures but running all my equipment for these tests would be too much time intensive unless everyone here gets the thing pissed out of it!
Thank, thank you very much, until then,
See ya
Bern
Not sure I understand, but if you mean a number of individual drivers feeding a horn, then this was first done back in the 1930s with compression drivers:
http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=26874&stc=1&d=1185738634
There was a four driver manifold as well as horn loaded line arrays of wide band-width [BW] point source [cone] drivers, but couldn't quickly find any pictures.
GM
http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=26874&stc=1&d=1185738634
There was a four driver manifold as well as horn loaded line arrays of wide band-width [BW] point source [cone] drivers, but couldn't quickly find any pictures.
GM
Even a pair of twin 12inch speaker cabinets can be very loud.
I bought 4 off Fane 50WRMS speakers and was very impressed by the SPL.
I put 2 in each sealed cabinet.
I used them on a mobile disco in the 1980's.
I got away these speakers with up to medium sized venues.
I bought 4 off Fane 50WRMS speakers and was very impressed by the SPL.
I put 2 in each sealed cabinet.
I used them on a mobile disco in the 1980's.
I got away these speakers with up to medium sized venues.
Nice horn comb, hope woofers works simpler when bulked.
I WILL do measurements, but only as a personal adjustment when I manage to assembly my entire sound system but I would prefer more feedback first. I just dunno, there are trucks with woofers hanging, lets say 100 woofers, but with the approprietly designed horns you could bring down that number by a factor of almost 10 times. A 9dB increase on the spl of 10 woofers would be equivalent to aprox. 8 times that (2.2.2, 2x for each 3dB increase), a total of aprox. 80 woofers as of their sound efficiency. That unless the areas of all the 100 woofers, installed without horns at all, happen to sum up in what concerns the proper area for impedance match of speaker and air at low frequencies.
Lets do the math: 80 15" woofers equals an area of a 94", single, hypothetical woofer. Given that the theorical horn for a cutoff frequency of 20Hz the mouth opening of the horn should have an area equal to that of a 383" single hypothetical woofer. Well a 94" woofer area wouldn't even compare to that of a 383" inch woofer so all those speakers woulnd't be even near achieving their full efficiency at 20Hz. 🙄
What did I mean here? 😀
I WILL do measurements, but only as a personal adjustment when I manage to assembly my entire sound system but I would prefer more feedback first. I just dunno, there are trucks with woofers hanging, lets say 100 woofers, but with the approprietly designed horns you could bring down that number by a factor of almost 10 times. A 9dB increase on the spl of 10 woofers would be equivalent to aprox. 8 times that (2.2.2, 2x for each 3dB increase), a total of aprox. 80 woofers as of their sound efficiency. That unless the areas of all the 100 woofers, installed without horns at all, happen to sum up in what concerns the proper area for impedance match of speaker and air at low frequencies.
Lets do the math: 80 15" woofers equals an area of a 94", single, hypothetical woofer. Given that the theorical horn for a cutoff frequency of 20Hz the mouth opening of the horn should have an area equal to that of a 383" single hypothetical woofer. Well a 94" woofer area wouldn't even compare to that of a 383" inch woofer so all those speakers woulnd't be even near achieving their full efficiency at 20Hz. 🙄
What did I mean here? 😀
Hello, sorry for big bump! I wanna share some information this one guy who fixes broken loudpspeakers in my town told me: that individual speakers in conventional boxes do not sum up their areas as whatever is the interest. So he says, but I still take one step back for doing my own measurements. Ok, until soon, c ya.
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direct radiating speaker's spl will sum 3db if you double speakers. 6db if you also double amps. but they will not move in space from 4pi to 1/2 pi and sum to lower frequencies like horns do. I hope that is what you mean. also if those boxes are not wired in series -parallel you might start a fire. read more about horns.
Maybe the little air gap between speakers is well sufficient to channel a balancing pressure which gives too much independence to the speakers. Maybe just little horns the exact size of the radiatior connected frontally to a single mouth would give the sum of areas?
You get the sum of the areas anyway. 4 drivers move 4 x the amount of air as one driver. Period. Those are the laws of physics. Where it gets more problematic is in the midrange & higher frequencies when the individual sources when mounted on a flat baffle do not sum coherently due to the differing phase angles resulting from the varying physical distances from the listening position. The output lobing results in a/ a more or less dense comb-filter effect with high-Q notches rippling through the response, and b/ an apparent reduction in HF output relative to the LF. Strictly speaking it's not a 'reduction' as such, but reduced HF levels is the effective result. The DSL Unity horn approach is probably the best mechanical / physical solution to coupling multiple drivers together coherently over a reasonable BW without resorting to digital delay, or a much larger number of drivers in an EQ'd nearfield array etc.
First part correct for coincident drivers, which means they are in phase and shorter than 1/4 wavelength removed from each other. This is how large arrays can get efficiencies of well over 25%.
Second part not correct. A large array can radiate even bass in 2pi, hence the large efficiencies.
Conventional sub-bass horns tipically don't have their dimensions larger than 3ft wide at their mouths, so, for a 9ft² cone the equivalent number of speakers is 56, which is an ammount somewhat really close to what I got. So you people make your bets here. You may have seen videos of 400W horned boxes that shakes everything even a yard distance. The actual power of the 54 6" speakers I have is somewhat in the range of 3500W. I got 2 woofers of 1700W each, if the bass of the many-speaker assembly does not surpass or even aproaches the woofers SPL then we have a clear answer here. Below, a picture of my woofers. Note that the woofers box contains a port, which might add a real lot of SPL compared to the smaller ones which are sealed. It will take a while from now, because 18 of these speakers still need to be fit into a box.
Briefly reviewing some calculations, if the theorical optimal cone diameter for a frequency of 40Hz happens to be 340", then the necessary ammount of 6" speakers to match that same area is about 4000 thousand speakers!! 🙁
Briefly reviewing some calculations, if the theorical optimal cone diameter for a frequency of 40Hz happens to be 340", then the necessary ammount of 6" speakers to match that same area is about 4000 thousand speakers!! 🙁
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I'm a bit lost, since you seem to be jumping around on different subjects a bit. In this case, I think (?) you are arguing that optimal bass-horn sizes are very large. This is quite true -it's a well known fact. However, 99.999% of people are not in a position to be able to use full-sized horns, since in most cases it would mandate building a room or even a house around them. So they have to compromise on outright coupling efficiency in the LF. That's just life. We live with it.
Note of course that depending on radiation angle and position, the horn enclosure can be physically smaller than the optimal since you can use boundary loading (1/4 space, 1/8 space etc.) as part of the horn's expansion, increasing its effective size. That's what corner-horns do.
Note of course that depending on radiation angle and position, the horn enclosure can be physically smaller than the optimal since you can use boundary loading (1/4 space, 1/8 space etc.) as part of the horn's expansion, increasing its effective size. That's what corner-horns do.
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Yes I am jumping subjects.
Please people, just have a time keeping on talking around, geeks like me are far too unrequestable for anything past incovenience. Just as my grammar is that bad AND I am a dumb noob in terms of what you people use to chit-chat here lets just quite ignore my job on giving the pressuposed attention because I have no load to hook about.
And you are right, subwoofers with badly designed boxes will, indeed, shake your plaster ceiling to the point of nearly damaging the thing, a lot, if cornered in the room, but intelligibility is neglected.
The thing is, the 54 speakers, working together, should sum to the perfect mouth area for a frequency cutoff of 200Hz as in a ideal horn project demands. Well, thats quite high tone but the difference should be noticeable. All I ever summed together by now was 16 of these speakers (equivalent to a 24" cone, which is the ideal for a 680Hz cutoff frequency). I don't know, just sharing experiences which for me is what counts. I like the sound produced by this speaker wall, I don't know if they were somehow summing their power more efficiently past the 680Hz, but I am considering here that the perfect horn for a given frequency has its mouth as wide, and its lenght as far, as one wavelenght of the desired cutoff frequency.
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