You never calculate this number for rcf, even though it's more impressive than the pd!
Furthermore I'm not sure who's calculating right, have a look at this thread:
http://forum.speakerplans.com/dual-kilomax-18a-horn-pics-and-olans_topic8740_page5.html
saying:
"What one looks for is motor strength which is BL/sqrt(Re)"
I've allways wanted to play around with the rcf lf21n551, but now I ended up with an beyma 21sw1600Nd, I even had two pd.2150 at one point, but eventually i sold them for about £550 br boxes included.
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Yes, 292 for the RCF...
Calculating BL²/Re or BL/sqrt(Re) of a serie of speakers, you'll get the same ranking order. I've not been far with math at school, but there it is not too much far ^^ And qts is interesting in itself too...
Linear xmax is only a mechanical measurement...it don't say you xmech, neither if response will be linear with long throw.
Sorry, i remember having wrote last message in multiple times, discovering the rcf at the end, so the message is not writen well, a bit confusing.
Calculating BL²/Re or BL/sqrt(Re) of a serie of speakers, you'll get the same ranking order. I've not been far with math at school, but there it is not too much far ^^ And qts is interesting in itself too...
Linear xmax is only a mechanical measurement...it don't say you xmech, neither if response will be linear with long throw.
Sorry, i remember having wrote last message in multiple times, discovering the rcf at the end, so the message is not writen well, a bit confusing.
Hey see what infomation i found about bl
"first article"
The BL factor (drive factor), given in Tm (tesla-metres), gives the strength of the motor structure applied to the voice coil. A high drive factor is a precondition for high sensitivity and, at the same time, damps the speaker's self-resonance. If the BL factor is too high, however, bass reproduction will be poor. Where it is too high, the self-resonance will be exaggerated and the pulse response will be poor at low frequencies.
"second article"
Take any woofer and double the BL product and compare it to the original in a simulated sealed box design. The driver with double the BL has a 6dB advantage in sensitivity but it will role off quicker making it appear to make less bass. This is not completely true, but rather shows how system design often requires going beyond the box and woofer to achieve the SPL goals you need. If the driver has very high BL product it will have very high dampening and impedance. The high impedance reduces the current from the amplifier under the same voltage (gain) and while the driver is extremely efficient, it also pulls less power from our voltage source. The driver with lower BL product will pull more power from the amplifier and displace more air but with lower dampening.
To correct this low Q problem we must place EQ into the system to shape the response and boost the amplifier voltage where appropriate to pull the same amount of power as before. If the driver has headroom (xmax) Then it will move more air than its lower BL counterpart with the same amount of power even for extremely low frequencies. The lesson here is don’t assume the box + driver raw frequency response is the final say in your performance as port or additional filters can also play equally important roles in our final response. The real limits are power and displacement.
so my Beyma is enough good for low frecuencly and yes you can see it to paper has best 20hz - 40hz spl also see something about qts (electrical and mechanical factor of speaker losses. If it is high smaller losses)
The first parameter to look at is the Qts.
This particular parameter will show which category the speaker will be best for. Remember these are guidelines, and there are always exceptions. Usually you can go a little either way with your Qts values for each of these categories.
.40 and above. As you go higher in value above .40, your speaker will only have flat response in very large vented boxes or sealed boxes. .40 to .50 will usually work well in a sealed, vented band pass box. That is an enclosure with a sealed rear chamber and a vented front chamber. Usually the .45 to .55 area is best for this type of box.
.37 to .40. This category works well for larger subwoofer boxes where the box can go as low as possible, and it won’t be used above 80 to 100 Hz. These woofers tend to lack punchy mid bass detail but still respond quick enough in the low bass region.
.30 to .36. This category would be the best choice for a high output subwoofer where the box can reproduce low frequencies without having to use a lot of equalization. This is a good region for the bass speaker of a full range box. Band pass enclosures with vented chambers on either side of the driver like Qts values in this area. Values in .35 area will perform well in larger boxes and values in the .27 to .30 area will be best for smaller band pass boxes with a slightly higher low frequency limit.
.26 to .29. This range is ideal where box size is critical and you still desire to get flat response to your tuning frequency. If you choose a woofer with a Qts of lower than .27, added equalization will be required to get flat response to your tuning frequency. This is a good area for small, full range boxes and small subs.
.22 to .26. Speakers in this area are ideal for dedicated mid bass speakers and small bass cabinets where added equalization is required. There is nothing wrong with this approach. The lower the Qts, the quicker the cone can move. With some careful equalization, you can end up with a stunning subwoofer in a smaller box size.
.21 and below. This range would work well for a horn loaded mid bass speaker. It would also be good for a mid bass component in a direct radiating full range box. You will have hard time getting low bass out of any speaker with a Qts below the .20 area.
Whatever the value, Qts should not be the only parameter to consider in your box design. An understanding of how Fs [free air resonance] and Vas [volume of air that matches the suspension springiness of the cone assembly] will be required. Understanding how these figures interrelate will help in determining speaker selection. Below is an optimum box design chart.
Of course your beyma is a beast. But the title of the thread is most powerful 21". It's just not the most powerful. And spl chart bellow 100hz isn't of any use. Power from amp is cheap. Efficiency is no more a problem nowday. Volume displacement (Vd=Sd x Xmax) is the problem for sub.
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Yes xmax is a problem for my speaker there are speakers with xmax 20mm like RADIAN 2216 NEO....
Hi koutrou,
Post #100: "How many litres sould be my subwoofer for my driver do you have any idea ? Beyma brand recommended 100 - 250 litres but do you think that this is truth or i can make a biger cabinet for example 500 litres ?"
Sorry for missing your question. In Post #44 I showed a simple bass reflex (vented) box w/ Vnet=230L. I would consider that at the high end of enclosure volumes for your Beyma. The bigger the enclosure, and the lower you tune it, the more displacement at the low frequencies. Generally, drivers don't like to be used w/ volumes above their Vas. Especially not for PA usage. I would stick w/ the manufacturers suggested volume range.
Regards,
Post #100: "How many litres sould be my subwoofer for my driver do you have any idea ? Beyma brand recommended 100 - 250 litres but do you think that this is truth or i can make a biger cabinet for example 500 litres ?"
Sorry for missing your question. In Post #44 I showed a simple bass reflex (vented) box w/ Vnet=230L. I would consider that at the high end of enclosure volumes for your Beyma. The bigger the enclosure, and the lower you tune it, the more displacement at the low frequencies. Generally, drivers don't like to be used w/ volumes above their Vas. Especially not for PA usage. I would stick w/ the manufacturers suggested volume range.
Regards,
Here's some good advice man.......do NOT buy these woofers and drivers.
Buy a pair of decent 2x18" subwoofer cabs, and a pair of 2x12" or 1x15" main speakers with horn tweeters. Preferably powered. Set it up, and learn how to run it. It will be plenty loud for 500 people indoors..........
........unless you are trying to deafen them permanently with poor sound, which is what you're going to do if you try to build something yourself. Unless this is all just a massive troll.
I have sound system like that man and it is not pretty loud i want extream power something like that http://www.sweetwaveaudio.com/sales/1990-large/meyer-sound-msl-6.jpg and that http://nexo-sa.com/images/products/54/hero.jpg i am near to do it ,not best quality but also not bad....
Its simple and easy Koutrou, when you want to shoot with with a Bigbanger then you need to pay a Bigbanger!!! And I do doubt that you are able to pay the price! Last price that I do know was around 35.000 EU for a pair! And then you need a matching Bss for them! Takes another 30.000 EU!
And apart from the Moneything, the MSL-6 is not what you can use. Its a long distance, longthrow HigPower System and nothing for the 500 Poeple Danceparty!
And apart from the Moneything, the MSL-6 is not what you can use. Its a long distance, longthrow HigPower System and nothing for the 500 Poeple Danceparty!
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I have Buy 2 longthrow horns JBL 2386 A (116db sensitivity) for my midhig ,now I am working to made 80cm midbass horn with a big sensitivity and almost flat response 80hz - 500hz... so with 2 15" midbass and 2 drivers for midhigh i will make something like msl6 not exactly the same but enough good job.... and for subs 2 X1 cabinets with dimensions for 21" woofer...
Let me be honest, when I do read your posts, I do get the feeling that you do not even have the smallest idea of what you want to do. Its similar to a hobby car mechanic that is able to change the tires on his car, maybe the oil or the sparkplugs and now he wants to enter and rule the F1 Business!
The 2386 is a nice working horn no Question, but lightyears away form a MSL-6.
This nice little thinggy fires with 3 X 2inch throat drivers for the MidHigh Section on one single special designed Horn and all of that is electronically controlled!
You are going to build up a little Cessna and try to fight against a Eurofighter!
A 80 cm Midbasshorn??? Aha, I am impressed and hoiw should that work and look???
The 2386 is a nice working horn no Question, but lightyears away form a MSL-6.
This nice little thinggy fires with 3 X 2inch throat drivers for the MidHigh Section on one single special designed Horn and all of that is electronically controlled!
You are going to build up a little Cessna and try to fight against a Eurofighter!
A 80 cm Midbasshorn??? Aha, I am impressed and hoiw should that work and look???
midbass horn would looks like this http://inlowsound.weebly.com/diy-80hz-midbass-horn.html but not exactly this , also will has and bass reflex port for more bass in combine with 2 jbl horns would reach more than 140db peak... maybe 143db msl 6 has 145-146 db peak not big difference ,the only difference i think will be in the quality.... be sure that my speakers will have more than 140db the Meyer Sound JM-1P is a simple powerful speaker and has 138db my speakers will be full hornloaded so of course higher spl.... when i makes and end them i will show the results.....
Okay whatever! The last that I will tell you is, that you will fail! Why? Because you do not have even 5% of the nessary knowledge, understanding and experience to build such a speakersystem!!!
A very well known and famous american Loudspeakerdesigner once said:
Any one can build a Loudspeaker, sadly some really do!!!
A very well known and famous american Loudspeakerdesigner once said:
Any one can build a Loudspeaker, sadly some really do!!!
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This is not going to have enough output below 1000hz to keep up with your midbass (kick) horn, you're going to need a true midrange speaker/horn. Most fully horn loaded PA systems are at least 4-way: sub, midbass/kick, midrange, tweeter.
Yes i know but would be more difficult make too many horns and combine them with well. My horn is around 106 db not extream output but good for midlow frequency ( View image: 1 , View image: 2 , View image: 3 ) and my 2" driver midhigh 116db ( View image: jbl 2386 A with crossover ) i will cross them active to 500 hz - 600 hz for smoother response.....
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xaxaxa yeah see something important and interesting this is golden frecuencly response for ear ( View image: golden frecuencly response for ear ) so flat response is not smooth just flat so all those midbass flat frecuencly response is just but quality and not "smooth" , for example see the frecuencly response of Turbosound TA880h ( View image: Turbosound TA880h SPL ) this is not flat, has very good sound and looks like more with "golden frecuencly" for ear..... so flat dont means and good !!
Oh my, if you build an all horn system with 21 inch bass and upper range that will allow the same spl level as the 21" TH's, put all the amps on max in a space for 500 people, set equalizer at Golden ratio....
Something like shellshock comes to mind to describe the effect. Be carefull what you wish Koutrou.
Something like shellshock comes to mind to describe the effect. Be carefull what you wish Koutrou.
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