Hi all
Can someone please assist me in getting a plan for Beyma 18G50. Unfortunately, I have 4 of these units and would like to use them for high quality PA applications. (Response must be from 34Hz to 100Hz at least @ 100dB 1W)
I know they are not suited for TL or Manifold designs but would prefer to use them in these applications.
For a TL, the size gets to 479 liters. I have seen the Beyma 18G50's in a manifold design but have no Hornresp simulation of it to see if it what I am looking for?
Are there some other designs whit better performance and/or response?
Appreciate any feedback from the experts?
Regards
Henk
Can someone please assist me in getting a plan for Beyma 18G50. Unfortunately, I have 4 of these units and would like to use them for high quality PA applications. (Response must be from 34Hz to 100Hz at least @ 100dB 1W)
I know they are not suited for TL or Manifold designs but would prefer to use them in these applications.
For a TL, the size gets to 479 liters. I have seen the Beyma 18G50's in a manifold design but have no Hornresp simulation of it to see if it what I am looking for?
Are there some other designs whit better performance and/or response?
Appreciate any feedback from the experts?
Regards
Henk
Attachments
Hi all
Can someone please assist me in getting a plan for Beyma 18G50. Unfortunately, I have 4 of these units and would like to use them for high quality PA applications. (Response must be from 34Hz to 100Hz at least @ 100dB 1W)
I know they are not suited for TL or Manifold designs but would prefer to use them in these applications. For a TL, the size gets to 479 liters. I have seen the Beyma 18G50's in a manifold design but have no Hornresp simulation of it to see if it what I am looking for?
Are there some other designs whit better performance and/or response?
Regards
Henk
Hi hzwart,
Not quite sure just what your primary goal is. You said that you wanted to use the beyma G50's for a "P.A." application, which may be very different from what a "TL", or "IB manifold" is designed to do. I'm very familiar with "Beyma", and consider it to be a "fair" choice, as compared to some other pro-sound audio drivers available. As I have discussed in a previous topic on this website (http://www.diyaudio.com/forums/subw...n-3-cu-ft-sealed-box-nht1259-replacement.html), you need to be very vigilant, when shopping and reading spec sheets. Beyma, as well as a few others, chooses to use their own (not the standard) method when publishing their driver test results.
For example. The standard method for testing the drivers "sensitivity" is feeding the driver 1 watt which is described as: 2.83 volts into an 8 ohm load, and measuring it's audible output (with a microphone) at a distance of 1 meter away from the driver's center. I won't go into any of the technical details, for the sake of those who may trying to stay awake
.My point. Beyma decided to use take the 2.83 volts, and feed it into a 2 ohm driver (which is equivalent to 4 watts), giving this drivers a 6 decibel advantage in the end result; you can take a look for yourself at their own spec sheet. Look closely at the sensitivity measurement.
It says: 98 dB 2.83v @ 1m @ 2ohm, Take a look.
https://www.google.com/url?sa=t&rct...qApcVRDVpvh-pm7n2CdgDlQ&bvm=bv.55123115,d.eW0
In reality, this driver's true 1 watt SPL would be 92db, not 98; that's a big difference on the stage when your amps are dishing out everything they've got any ready to start clipping! In my own opinion, Beyma's are "good", but if you need very high sensitivity (like 98-100 db), then get a driver that can deliver "a true" 98 to 100db. Other than that, I think they'll do just fine on all other aspects of "Pro-work".
Here's a driver that'll "Take a lickin'...".
18LW1400 Eighteen Sound 18LW1400 18" Speakers - Eighteen Sound 18LW1400 18" subwoofer - Eighteen Sound 18LW1400 is a 2,000 watt extended low frequency woofer that has goes down to 28Hz. Eighteen Sound 18LW1400 woofers are available here. 18 Sound spe
I have two, used in a very large "bass amplifier" application, but can also do pro audio, which is what they were designed for. These are much like the JBL 2242H (if you're familiar), but likely just a tad better, due to their "cooling system".
rigtec, cheers
Hi all
Can someone please assist me in getting a plan for Beyma 18G50. Unfortunately, I have 4 of these units and would like to use them for high quality PA applications. (Response must be from 34Hz to 100Hz at least @ 100dB 1W)
I know they are not suited for TL or Manifold designs but would prefer to use them in these applications.
For a TL, the size gets to 479 liters. I have seen the Beyma 18G50's in a manifold design but have no Hornresp simulation of it to see if it what I am looking for?
Are there some other designs whit better performance and/or response?
Appreciate any feedback from the experts?
Regards
Henk
The Beyma 18 G50 can be used in Reflex or Folded Horns. I believe Beyma promoted the 18 G 50 for Folded Horns. It is a very versatile driver and efficient. However that design you made is not the best method to take full advantage of that driver.
Go to Beyma and download the TS Parameters. It will be in their discontinued section.
hzwart said:
"...I know they are not suited for TL or Manifold designs but would prefer to use them in these applications..."
Sorry,
forgot to say, you may very well be able to use the "18G50" for a "IB Manifold" application. The thing is that in an infinite baffle (home theater), you'll need to be aware of the "mechanical limitations" (mech lim) imposed regarding this particular alignment. Typically speaking, drivers operating in an enclosed environment, have a degree of support, as the air in the enclosure assists in keeping the cone/voicecoil assm from traveling too far in one direction or the other.
In an IB application (free air), you must exercise good judgement, as to how much power can "safely" be applied; perhaps through the implementation of an electronic "high pass" (ultrasonic) filter or a "signal compressor", limiting the spikes in the program material or music. As far as the TL alignment, someone else here (I'm sure) will be able to help you with that as this is a bit more complicated, to which I have no (zero) insight. Best to you!
rigtec
"...I know they are not suited for TL or Manifold designs but would prefer to use them in these applications..."
Sorry,
forgot to say, you may very well be able to use the "18G50" for a "IB Manifold" application. The thing is that in an infinite baffle (home theater), you'll need to be aware of the "mechanical limitations" (mech lim) imposed regarding this particular alignment. Typically speaking, drivers operating in an enclosed environment, have a degree of support, as the air in the enclosure assists in keeping the cone/voicecoil assm from traveling too far in one direction or the other.
In an IB application (free air), you must exercise good judgement, as to how much power can "safely" be applied; perhaps through the implementation of an electronic "high pass" (ultrasonic) filter or a "signal compressor", limiting the spikes in the program material or music. As far as the TL alignment, someone else here (I'm sure) will be able to help you with that as this is a bit more complicated, to which I have no (zero) insight. Best to you!
rigtec
The Manifold shown is inefficient for PA. Thats why EV stop making that design decades ago. He is better off using Folded Horns as the Beyma 18 G 50 meets the requirements to perform in a Folded Horn.
Hi OMNIFEX,
You're absolutely right! I wasn't suggesting that the 18G50 be used in a "Manifold Technology" type sub enclosure. I was talking about using it for "Home theater" only, as in a, "through the wall" (free air) manifold.
Cheers
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For example. The standard method for testing the drivers "sensitivity" is feeding the driver 1 watt which is described as: 2.83 volts into an 8 ohm load, and measuring it's audible output (with a microphone) at a distance of 1 meter away from the driver's center. I won't go into any of the technical details, for the sake of those who may trying to stay awake
My point. Beyma decided to use take the 2.83 volts, and feed it into a 2 ohm driver (which is equivalent to 4 watts), giving this drivers a 6 decibel advantage in the end result; you can take a look for yourself at their own spec sheet. Look closely at the sensitivity measurement.
It says: 98 dB 2.83v @ 1m @ 2ohm, Take a look.
https://www.google.com/url?sa=t&rct...qApcVRDVpvh-pm7n2CdgDlQ&bvm=bv.55123115,d.eW0
Not quite sure where you see that. Could you be a bit more precise because all I see is an FR curve taken at 1W@1m on axis and an impedance curve that shows an 8Ohm driver. What am I missing?
If you scroll down to the "Technical specs" section, see "Sensitivity", you'll see a 2 ohm driver being fed 2.83v. This translates to 4 watts input (or 6db).
Greg
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I see,
Guess it's possible. I interpret that as a pretty close "Omega" symbol. I've never seen PI posted in any of the other pro-audio driver manufacturers "sensitivity spec". Sometimes in the "description" of the testing procedure, they may provide that info, like with *** on the sheet somewhere. Isn't that typically measured in "full field" (non-reverb chamber) environment?
Greg (rigtec)
Drivers are usually measured on an IEC baffle like this:
IEC baffle in Anechoic Chamber
But I'm sure I've seen half space measurements from manufacturers other than Beyma.
IEC baffle in Anechoic Chamber
But I'm sure I've seen half space measurements from manufacturers other than Beyma.
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Greg,
The 18G50 does specify the measurement is taken with it on an infinite baffle in an anechoic chamber, which is the equivalent of 2 pi, half space.
It's DCR of 6.1 ohms is a bit on the low side for a nominal 8 ohm speaker, but "close enough for rock and roll".
Low frequency enclosures are often tested outdoors, as making an anechoic chamber anechoic below 100 Hz is horribly expensive and large.
The outdoor tests are usually done with the cabinet on the ground, half space, though cabinets designed for suspended usage may also include free space measurements as well.
Thank you for the reply's. Unfortunately, I have these drivers and would like to use them in an optimum enclosure to get the best out of them.
I have plotted them in TL's and Horns as per EPA's sim. But what is the optimum enclosure that I can still handle with the response I want?
Due to the 18G50 limited power capability, I have to use them in one stack to optimise the output and keep the drivers within the limited xmax. Hence my need to look for the optimum enclosure.
Well, this is maybe to much to ask for seeing that it is always a compromise between low, small and louder?
A reflex will not do it. So can it be a Horn, TL or manifold?
The reason why I require a response from 34Hz is that I can use one enclosure per side for small venues and still get a decent sound of high quality.
Appreciate all your comments seeing that we can never stop learning.
Regards
I have plotted them in TL's and Horns as per EPA's sim. But what is the optimum enclosure that I can still handle with the response I want?
Due to the 18G50 limited power capability, I have to use them in one stack to optimise the output and keep the drivers within the limited xmax. Hence my need to look for the optimum enclosure.
Well, this is maybe to much to ask for seeing that it is always a compromise between low, small and louder?
A reflex will not do it. So can it be a Horn, TL or manifold?
The reason why I require a response from 34Hz is that I can use one enclosure per side for small venues and still get a decent sound of high quality.
Appreciate all your comments seeing that we can never stop learning.
Regards
I have plotted them in TL's and Horns as per EPA's sim. But what is the optimum enclosure that I can still handle with the response I want?
Four horns arrayed in a "Block" configuration will give the highest levels per watt. Stacking the horns increases mouth size, raising the efficiency, and lowering the f3. The bass reflex alignment is next, as far as output per watt, and will likely far exceed in low frequency extension, especially when "corner loading" is implemented.
Four of these drivers will permit 3,000w RMS/6,000w program! With 9mm xmax each, you should never have a problem, as long as you use your head and watch that your amp's "clip indicator" lights don't stay on; occasional blinking should be okay.
The TL's and the manifolds are too inefficient to consider for professional, high output (130db+) use, but may do very well in a much more "personal" environment" e.g., backyard bar-B-Q, Tailgate parties, small banquet's...
Hope that helps... "I'm trying to stay out of trouble"
rigtec, regards
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I hate to give you the bad news but, using one horn per side is not going to give no where near 34 Hz. I think it is time for you to punch in the TS Parameters of the Beyma 18 G50 in Horn Response and face the harsh reality.
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