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Sounds for Car (pg. 3)
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| gehzumteufel |
Damn. What is your educational background? |
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| Axer |
| quote: | Originally posted by 3F05Q
JL makes a good quality product, but their woofers are lacking. They could be better, but their foolish pride has kept them from their full potential when it comes to sound quality in their drivers (as well as thinking their shallow subs are good... mine will be better :)). I have a 300/4 amp, and I like it. Some of their board layout is a bit convoluted, and that's according to one of the best analog systems engineers I've ever met (and now work with), but I was also told it doesn't affect sound quality, just makes it a bit inefficient. Anyway...
If I was in your position I'd grab a couple of these: http://www.creativesound.ca/details.php?model=SDX10
These are a reincarnation of the old Adire Audio tens. The motor technology in these things gives it a FLAT BL curve (that's magnetic field in relation to VC position) so there's no BL compression like you'd see in a typical driver. What does this mean? Smaller diameter and bigger stroke as opposed to the other guys' much bigger diameter and smaller stroke (SPL is relative to the volume of air moved), MUCH lower harmonic distortion due to the linear BL, and much better musicality than a typical sub. Also the efficiency is better since it doesn't utilize an over or underhung VC design. I did some measurements of the SDX15 a few months ago, and was impressed at how flat the frequency response was.
If you do a search for Adire stuff you'll find that their drivers were utilized in both the SPL and SQ markets. If you do a search for the SDX10 you'll find some good reviews.
Ported: 43 Litres, 16oz polyfill, 3" flared port 17" long will result in a box tuning of 24Hz, (pulled these from the recommended values) and you'd probably be flat in your car to 20Hz. A single SDX10 in this configuration should get you 108dB with 300 Watts, 111dB with two. Remember that 3dB increase is a doubling of power.
Sealed: 24 Litres, 16oz of polyfill, you'd be down 3dB at 30Hz... probably flat in your car to 25...27Hz. 250 Watts or so.
Probably throw a lowpass (2nd or 4th order) on it anywhere from 80Hz - 120Hz, depending on the midwoofs, and you're golden.
At any rate, good luck. |
Even if it meant something, I wouldn't recommend this to a customer. |
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| 3F05Q |
| quote: | Originally posted by Axer
Even if it meant something, I wouldn't recommend this to a customer. |
What I described means a lot. You wouldn't recommend it to a customer because it's not "der.. uhh.. get a Kicker cuz your homies will think it's tight."
A typical speaker works by utilizing the behavior of an electrical current in a magnetic field, the Lorentz force. F = qv x B (that's 'cross', not 'times'). 'qv' is the current in the wire, or in this case the VC, and B is the magnetic field. The current in the wire, supplied by the amplifier, should be linearly proportional to the audio signal sent from our audio source. If not, your amp is crappy :). Our ideal outcome is for the Force on the cone by the VC to be linearly proportional to the input signal. As a result we want to keep the magnetic field a constant magnitude througout the entire range of motion of the woofer. Following Axer?, cuz here's where it gets good...
Most driver motors DO NOT have a uniform magnetic field throught the range of woofer motion. It drops off CONSIDERABLY off of the center of motion. As a result the Force drops off exponentially as the woofer is moving outside of the center of the moving range. So what do we call something that attenuates output as input is increased? A compressor. Significant decrease in Harmonic Distortion is a plus too, especially third harmonics, which matter most.
Now, I'm fairly certain that the original poster won't take my advice, but someone who reads this might. You may not recommend this to a customer mainly because you don't know anything about this driver, but I would, and I'm an audio transducer designer with a couple of patents under my belt and a couple more on the way.
Teh Physiks has spoken. |
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| Axer |
| quote: | Originally posted by 3F05Q
What I described means a lot. You wouldn't recommend it to a customer because it's not "der.. uhh.. get a Kicker cuz your homies will think it's tight."
A typical speaker works by utilizing the behavior of an electrical current in a magnetic field, the Lorentz force. F = qv x B (that's 'cross', not 'times'). 'qv' is the current in the wire, or in this case the VC, and B is the magnetic field. The current in the wire, supplied by the amplifier, should be linearly proportional to the audio signal sent from our audio source. If not, your amp is crappy :). Our ideal outcome is for the Force on the cone by the VC to be linearly proportional to the input signal. As a result we want to keep the magnetic field a constant magnitude througout the entire range of motion of the woofer. Following Axer?, cuz here's where it gets good...
Most driver motors DO NOT have a uniform magnetic field throught the range of woofer motion. It drops off CONSIDERABLY off of the center of motion. As a result the Force drops off exponentially as the woofer is moving outside of the center of the moving range. So what do we call something that attenuates output as input is increased? A compressor. Significant decrease in Harmonic Distortion is a plus too, especially third harmonics, which matter most.
Now, I'm fairly certain that the original poster won't take my advice, but someone who reads this might. You may not recommend this to a customer mainly because you don't know anything about this driver, but I would, and I'm an audio transducer designer with a couple of patents under my belt and a couple more on the way.
Teh Physiks has spoken. |
Now aren't you one twisted !
You think you can out smart any of us with a formula as ed as VC = B that you can save it. I have no idea what you're trying to find here. F ? LOL
Look buddy, that's the whole point of getting an amp, and that would cover up and even more amplify whatever proportion is lost from the audio output from the main unit. If you made that unit you're good. Any electronic equipment will deteriorate over the years. The subwoofer I was using, the skin was made out of some plastic material and that somehow gives a longevity to the product. Having it placed on a frame makes your car the box. With a pair of tweeters up front, you can never even have a slightest loss of effect or quality of sound at any in speed or motion. I hope you know how an equalizer works! JKN.
Good luck with your solo research! Hope you're getting paid for it. |
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| T-Soma |
| quote: | Originally posted by Axer
Now aren't you one twisted !
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You fail at internets.
BTW: Don't forget Dynaudio and Focal if you have some cash to splash around. They sound verrry nice. Obviously not the flattest response but who actually wants that in a car sound system? Not like your mastering/mixing tracks on your way to work :tongue2 |
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| 3F05Q |
| quote: | Originally posted by Axer
JKN.
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I hope that means something like 'just kidding'. If so, cool... if not, I'm gonna have an aneurysm.
At any rate... it's a horrible idea to mount a woofer free-air (there are very few exceptions to this, but I can't be bothered to get into it). The box is there for a reason, plain and simple. A ported box acts as a Helmholtz Resonator (look it up), for instance. Now, if you want to tie the BOX down, go for it.
Listen, my goal here is to help people make a decision by understanding how something works so that they can discern for themselves what's best for them. Also, every concept I've discussed is first-year physics courses, nothing upper division. I'm not planning on being a rocket scientist...anytime soon. :) |
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| Axer |
| quote: | Originally posted by 3F05Q
I hope that means something like 'just kidding'. If so, cool... if not, I'm gonna have an aneurysm.
At any rate... it's a horrible idea to mount a woofer free-air (there are very few exceptions to this, but I can't be bothered to get into it). The box is there for a reason, plain and simple. A ported box acts as a Helmholtz Resonator (look it up), for instance. Now, if you want to tie the BOX down, go for it.
Listen, my goal here is to help people make a decision by understanding how something works so that they can discern for themselves what's best for them. Also, every concept I've discussed is first-year physics courses, nothing upper division. I'm not planning on being a rocket scientist...anytime soon. :) |
J is the distance from my feet to your ass!
K = kick.
N is the number of times.
JKN = Joking?! LOL
I appreciate your long drunk posts my friend! I had more physics than you in my A' levels. 6 modules of them. :) |
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| Axer |
| quote: | Originally posted by T-Soma
You fail at internets.
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I have a life outside internet, unlike some people. :rolleyes: |
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| 3F05Q |
| quote: | Originally posted by Axer
I appreciate your long drunk posts my friend! I had more physics than you in my A' levels. 6 modules of them. :) |
And I have a DEGREE in Physics. Go look up what I've posted, you'll find it's legitimate. If you have a counter-argument with a reasonable scientific explanation then let's get cracking.
Those with the brains to research what I've said will find that it's honest advice.
I'm done. Anyone wanna discuss it more, PM me.
I have an aneurysm to stop now. |
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| gehzumteufel |
| quote: | Originally posted by 3F05Q
I hope that means something like 'just kidding'. If so, cool... if not, I'm gonna have an aneurysm.
At any rate... it's a horrible idea to mount a woofer free-air (there are very few exceptions to this, but I can't be bothered to get into it). The box is there for a reason, plain and simple. A ported box acts as a Helmholtz Resonator (look it up), for instance. Now, if you want to tie the BOX down, go for it.
Listen, my goal here is to help people make a decision by understanding how something works so that they can discern for themselves what's best for them. Also, every concept I've discussed is first-year physics courses, nothing upper division. I'm not planning on being a rocket scientist...anytime soon. :) |
lol he is just a jackass. at least he appears that way on TA. Clueless and smoking too much herb, and in turn, has not an ounce of articulate responses even in that small peanut sized brain he has.
On the flip side, I really liked your responses. Stuff I just never knew. :) |
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| Axer |
| Little dicks always running their mouth. |
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