Hey man here i found a similar 6 order design Speakerplans.com , how to this sub the front and backwave will not cancel each other and works well ?
Because the chamber/ ports are tuned to different frequencies, if the chambers and ports would be the same size, they would cancel each other out as well.
Koutrou, no offence ment it's this basic knowledge + & - phase knowledge you need to make a succesfull design. Following a speakerplan with a lot of rebuilds can prevent you from ending up with the mostpowerfull heap of speakers and drivers that dont quite work.
Hi koutrou,
Learning Hornresp Hornresp would be a very good starting point.
For an easy to build, functional box try the attached bass-reflex enclosure design (or, just keep it as a size versus output reference):
Regards,
Learning Hornresp Hornresp would be a very good starting point.
For an easy to build, functional box try the attached bass-reflex enclosure design (or, just keep it as a size versus output reference):
Regards,
Attachments
thanks guys but see that design he says that handles 145db max spl, Frequency response 28 - 110hz and the ports are the same gap.... how it works so good why not cancel each other now ? name of sub Fohhn Audio PS 9 http://www.fohhn.com/uploads/tx_fohhnproducts/PS-9_front2_int.jpg
http://www.fohhn.com/index.php?id=58&L=1&tx_fohhnproducts_pi1[fohhnproducts]=413&cHash=67ebd1cb1e
http://www.fohhn.com/index.php?id=58&L=1&tx_fohhnproducts_pi1[fohhnproducts]=413&cHash=67ebd1cb1e
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Hi koutrou,
Post #49: "...if i made different front and backwave ways it will works..."
In a BP6 the big chamber w/ the long port will give you the bottom frequencies, and the small chamber with the shorter port will give you the upper frequencies. It will only work if the chambers and ports are tuned together with the driver (or drivers) to work as a system. You need a simulation program to design such a system.
When you look at the xray view of the PS-9 in the Fohhn brochure, you can get the idea of what's going on. After that it's a lot of work to even get close.
Regards,
Post #49: "...if i made different front and backwave ways it will works..."
In a BP6 the big chamber w/ the long port will give you the bottom frequencies, and the small chamber with the shorter port will give you the upper frequencies. It will only work if the chambers and ports are tuned together with the driver (or drivers) to work as a system. You need a simulation program to design such a system.
When you look at the xray view of the PS-9 in the Fohhn brochure, you can get the idea of what's going on. After that it's a lot of work to even get close.
Regards,
The PS-9 of Fohhn works with a B&C 21" IpalWoofer and also the Ipal PowerAmping that comes from Powersoft working together with some very complex digital controlling and filtering, including a motioncontrol for the woofercone! The 145 db are the absolut maximum shortterm performance and surely not a continious Spl!
Let me ask you two questions koutrou! Are your really sure what you are doing, and are you sure that you do know how to build a loudspeaker???
Because when I do have a look at these enclosure sketch that you made, I do get the idea, that you do not have the nessary knowledge and understanding of that what you intend to do!
If you allready baught the Beyma driver then try to return it to your dealer, buy a Predevices PD2150 and build the 21" Scoop from Roger Mogale that you find on Speakerplans.com
I attach the PDF of the driver that is used in the PS-9! And no this driver is not for sale on the public market and the Ipal Amps also not!
Let me ask you two questions koutrou! Are your really sure what you are doing, and are you sure that you do know how to build a loudspeaker???
Because when I do have a look at these enclosure sketch that you made, I do get the idea, that you do not have the nessary knowledge and understanding of that what you intend to do!
If you allready baught the Beyma driver then try to return it to your dealer, buy a Predevices PD2150 and build the 21" Scoop from Roger Mogale that you find on Speakerplans.com
I attach the PDF of the driver that is used in the PS-9! And no this driver is not for sale on the public market and the Ipal Amps also not!
I dont know at all make subwoofers but know some things, cant give buck Bayma also this is great, powerful and very low frequency response with good xmax. Nice scoop do you know the sensitivity of this speaker ?
The sensivity of the scoop is always a question of the driver used in it! With a PD2150I would suggest around 100dB/W/1m, with the Beyma, when it works in the Scoop around 98 to 99 dB. But I think the Beyma isnt a really well working driver for a Scoop! Powerfull? 1400 AES and 2800 P max is okay but not that much! 10mm Xmax is at the lower end, maybe midfield of the 21" Driver range!
I am sure that you know some things, no question. But you need some technical knowledge about speaker contruction and need some experience for such a project that you have planned!
I am sure that you know some things, no question. But you need some technical knowledge about speaker contruction and need some experience for such a project that you have planned!
Dont see the AES watt, all the brands dont write the truth RMS watts , Beyma 21Pw1400Fe has the biggest and heaviest ferrite magnet of every PA woofer (not car audio) ,also has the best 20hz - 40hz spl i have see all spl of high power woofers. Neodymium magnet is 35% - 40% more powerful of ferrite but there isnt subwoofer with Neodymium magnet which weight more than 8 kg Beyma 21Pw1400Fe has 14.5 kg magnet , 8 kg Neodymium magnet is like 13 kg ferrite ,more powerful Neodymium woofers are B&C 21sw152 , Beyma 21SW1600Nd , 18 sound 21NLW9600. Also for example to understud that brands lies about AES watt B&C 21sw152 has the same weight Neodymium magnet with Beyma 21SW1600Nd but B&C write 2000 AES and Beyna 1600 AES so dont see about RMS and Beyma 21Pw1400Fe has better low SPL than those tow woofers.... , Precision Devices PD.2150 has only 6.12 Kg ferrite magnet this is funny but is good driver because of technology and voice coil but cant compare with other high power woofers which have also good technology....
Sure i need to learn more but i try and thats why i shows to you my plans to tell me your opinion see my last plans and effort --> 1st plan http://postimg.org/image/wvl3nuck9/ gaps idea from 184 Sub cabinet ( http://www.speakerplans.com/index.php?id=184sub ) , and second plan http://postimg.org/image/cq7586n81/ gaps idea from 18 sound MANIFOLDED bandpass ( http://www.eighteensound.it/portals/0/EnclosuresKits/18sound_double18_kit.jpg )
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Koutrou,
Another indication of powerhandling is the voice coil diameter. The bigger the voice coil diameter the more heat/power it can stand. The less compression due to heating of the voice coil the driver will have driven at max. From what i understood Neodymium magnets are not that happy driven very close to max power all the time. Heat and Neo is not a good combo.
You do understand this is them same output if driven max?
100 dB driver with 1000 Watt
97 dB driver with 2000 Watt
Any idea howmuch dB you need for the 500 people EDM partys?
Another indication of powerhandling is the voice coil diameter. The bigger the voice coil diameter the more heat/power it can stand. The less compression due to heating of the voice coil the driver will have driven at max. From what i understood Neodymium magnets are not that happy driven very close to max power all the time. Heat and Neo is not a good combo.
You do understand this is them same output if driven max?
100 dB driver with 1000 Watt
97 dB driver with 2000 Watt
Any idea howmuch dB you need for the 500 people EDM partys?
I think 2 good subs and 2 powerful speakers for voice are good for 150 - 300 people dont know how mach db those can output.....
Please...can other member explain him how much Koutrou is wrong in his so simple knowlege/understanding of speaker ? I'm just a novice compared to others here, but generally, there's always people for explaining things...
I'll try to give him some clues, but i'm only saying what i've learn after spending nearly 3 years reading it forum. And there's always different level of knowledge.
First : to make sound at low frequency, you MUST move the most air you can. To do that, you need a big "xmax" (i know, flat BL...but to start it's a good point). But there's different ways to mesure it, taking in account for some the unregularities of spider(S), and suspension, measuring thd... Generally, (linear xmax) calcul use voicecoil lenth, and airgap height. So if you want to compare equally the capability of moving air of same diameters speakers, you can compares theses datas :
beyma 21pw1400 fe: 25/12mm (xmax before damage 55mm)
BC 21sw152 : 30/12mm (xmax before damage 60mm)
PD 2150 : 30/15mm...
The 18sound 21NLW9600 datasheet don't give Hvc and Hg, but say they use (Hvc +Hg)/2 +Hg/4 formula for xmax. So it 14mm would be to compare to 21 for the beyma, 24 for the BC, and 26.25 for the PD. I let you interpret it...
I've forgotten the RCF LF21551 : 39/18mm : 33mm linear xmax...
2 ) Magnet power...You want to compare speaker force ? There's a data call BL. And another called Re. BL is the power of the motor. Re the resistance of the voicecoil. BL²/Re can be used to compare different motor efficiencies... Here again :
21PW1400fe BL²/Re =152
BC 21sw152 : 170
PD 2150 : 253...
Yes...the power of the PD is a monster. How ? Technologie, wire used for the magnet, different layers...don't know.
Another way, is to compare QTS...and 0,27 for PD is really efficient, compared to 0,34 for the Beyma, and 0,3 for the BC. But this affect a lot bandwith response...
3) At high level, there's "power compression", with heat. It can be used to compare power capabilities not using rated power. Again, for 1000w :
21PW1400fe : 3db
PD2150 : 2db
BC 21sw152 : ?
So...PD2150 seems to be winner... But his huge power would need to be used in a horn well simulated. I advice you to spend at least 2 weeks reading experiences on diyaudio before doing anything that would be waste of time for you. Search about hornresp use. A lot of work. But you're trying to do engeeniring, and that is not a piece of cake...
From those really partial point of view, you would have looked at the RCF lf21N551 in you're search of the most powerfull...(subjectivly)
And finally, using only one or two such sub is completly waste of money. You would end with better result using more speakers, less powerfull, but each moving less their cone as it is well know that moving more mm gives generally more iregularities, and so more distortion.
And i let others talking about what is phase, and how it's important with sub.
If you want some response simulation, a lot here like me love playing with the fabulous simulation toy hornresp done by David McBean.
But, now that you have the beymas, to help you choose the best box, we need to know what size of box in liters would you accept for it ? And what would be your crossover setting : frequency band, and db/oct. ?
I'll try to give him some clues, but i'm only saying what i've learn after spending nearly 3 years reading it forum. And there's always different level of knowledge.
First : to make sound at low frequency, you MUST move the most air you can. To do that, you need a big "xmax" (i know, flat BL...but to start it's a good point). But there's different ways to mesure it, taking in account for some the unregularities of spider(S), and suspension, measuring thd... Generally, (linear xmax) calcul use voicecoil lenth, and airgap height. So if you want to compare equally the capability of moving air of same diameters speakers, you can compares theses datas :
beyma 21pw1400 fe: 25/12mm (xmax before damage 55mm)
BC 21sw152 : 30/12mm (xmax before damage 60mm)
PD 2150 : 30/15mm...
The 18sound 21NLW9600 datasheet don't give Hvc and Hg, but say they use (Hvc +Hg)/2 +Hg/4 formula for xmax. So it 14mm would be to compare to 21 for the beyma, 24 for the BC, and 26.25 for the PD. I let you interpret it...
I've forgotten the RCF LF21551 : 39/18mm : 33mm linear xmax...
2 ) Magnet power...You want to compare speaker force ? There's a data call BL. And another called Re. BL is the power of the motor. Re the resistance of the voicecoil. BL²/Re can be used to compare different motor efficiencies... Here again :
21PW1400fe BL²/Re =152
BC 21sw152 : 170
PD 2150 : 253...
Yes...the power of the PD is a monster. How ? Technologie, wire used for the magnet, different layers...don't know.
Another way, is to compare QTS...and 0,27 for PD is really efficient, compared to 0,34 for the Beyma, and 0,3 for the BC. But this affect a lot bandwith response...
3) At high level, there's "power compression", with heat. It can be used to compare power capabilities not using rated power. Again, for 1000w :
21PW1400fe : 3db
PD2150 : 2db
BC 21sw152 : ?
So...PD2150 seems to be winner... But his huge power would need to be used in a horn well simulated. I advice you to spend at least 2 weeks reading experiences on diyaudio before doing anything that would be waste of time for you. Search about hornresp use. A lot of work. But you're trying to do engeeniring, and that is not a piece of cake...
From those really partial point of view, you would have looked at the RCF lf21N551 in you're search of the most powerfull...(subjectivly)
And finally, using only one or two such sub is completly waste of money. You would end with better result using more speakers, less powerfull, but each moving less their cone as it is well know that moving more mm gives generally more iregularities, and so more distortion.
And i let others talking about what is phase, and how it's important with sub.
If you want some response simulation, a lot here like me love playing with the fabulous simulation toy hornresp done by David McBean.
But, now that you have the beymas, to help you choose the best box, we need to know what size of box in liters would you accept for it ? And what would be your crossover setting : frequency band, and db/oct. ?
The post about weight of Magnetic structures that you typed koutrou, shows that you do not even have the smallest idea about what you are doing! The physical size and weight of a magnet stucture is one of the most unimportant technical specifications for a driver!
By the way I do doubt that the magnet structure of the Beyma weights 14.5 kg by a total weight of 19.9Kgs for the whole driver! Its the same magnestructure for 100 mm Voicecoils that Beyma uses for other drivers like the 18LX60 for example!
8 Kg of Neodymium are equivalent to 13 kg ferrit??? Wow thats a statement!
Hmm, to be honest, I personally dont know any conventionally Bassdriver that has a Neodym magnetstructure that weights 8 Kg!
Let me guess, you have succesfully installed a 18 " Woofer in a Cartrunk and now you feel you are called and ready for much more complex tasks!
By the way I do doubt that the magnet structure of the Beyma weights 14.5 kg by a total weight of 19.9Kgs for the whole driver! Its the same magnestructure for 100 mm Voicecoils that Beyma uses for other drivers like the 18LX60 for example!
8 Kg of Neodymium are equivalent to 13 kg ferrit??? Wow thats a statement!
Hmm, to be honest, I personally dont know any conventionally Bassdriver that has a Neodym magnetstructure that weights 8 Kg!
Let me guess, you have succesfully installed a 18 " Woofer in a Cartrunk and now you feel you are called and ready for much more complex tasks!
Just to add : ciare FXH-21-4 S : 6,5kg ceramic magnet. It neodynium equivalent : 620gr. And...of course. Magnet power depend of flux density...But without voicecoil, magnet is not a motor. So voicecoil is even more important than magnet, even if you don't see it in photos ^^
Thanks man for information i would a big box many litres and think 6 order boxes are more powerful from 1 way hornloaded and from the other ported. I would cross it to 120hz - 140hz i preferred low freqencly response down 30hz my cabinet....
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