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audioguru
Nobel Prize Winner
Canada
4218 Posts |
 Posted - Apr 25 2009 : 10:56:41 AM
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Hi Johnny,
I don't know which brands of speakers are available in Australia.
I think you should select a certain woofer then its spec's will show the size of the enclosure and whether it can be ported or not.
Speakers are tested with pink noise, not sine-waves. |
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wasssup1990
Nobel Prize Winner
A Land Down Under
2261 Posts |
Posted - Apr 25 2009 : 11:21:12 AM
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Hi John,
quote:
I don't know which brands of speakers are available in Australia.
I think you should select a certain woofer then its spec's will show the size of the enclosure and whether it can be ported or not.
I'll look around. I'm getting a 12 incher.
quote:
Speakers are tested with pink noise, not sine-waves.
Oh yeah I remember reading that somewhere. I think it's somewhere here.
http://sound.westhost.com/articles/pwm.htm
Where can you suggest I go to learn more?
Thanks!  |
When one person suffers from a delusion it is called insanity.
When many people suffer from a delusion it is called religion. |
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - Apr 26 2009 : 10:06:43 AM
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I learned a lot about audio by reading thousands of journals of The Audio Engineering Society. They might be in your local library. Years ago, Wireless World (British) magazine was good and also might be in your local library.
On the web True Audio, Altec Lansing and Rane have some good audio articles. |
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wasssup1990
Nobel Prize Winner
A Land Down Under
2261 Posts |
Posted - Apr 26 2009 : 10:35:02 AM
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Okay thanks for letting me know buddy.
I will look it all up. |
When one person suffers from a delusion it is called insanity.
When many people suffer from a delusion it is called religion. |
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wasssup1990
Nobel Prize Winner
A Land Down Under
2261 Posts |
Posted - Apr 27 2009 : 11:27:43 AM
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| Due to technical reasons I will not be able to decode a SPDIF audio signal with any of the microcontrollers I have. The data rate is just too high. I'll just get a dedicated SPDIF decoder chip instead. It's probably more cheaper and less space consuming anyway. |
When one person suffers from a delusion it is called insanity.
When many people suffer from a delusion it is called religion. |
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wasssup1990
Nobel Prize Winner
A Land Down Under
2261 Posts |
Posted - Apr 28 2009 : 11:01:27 AM
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| I've been thinking. I'm going to simplify the subwoofer. It'll have a wireless receiver but it won't have a computer and screen. This means that I'll have the wireless transmitter seperate, possibly placed on top of a subwoofer in a metal case with the computer and flip up screen. I'll do a drawing showing all units of the speaker system that will include all CENTER FL FR SL SR RL RR SUBWOOFERS and one head unit (Transmitter). FYI this system can be configured to have as many speakers asigned to a single audio channel as I want. However loud you want it baby! |
When one person suffers from a delusion it is called insanity.
When many people suffer from a delusion it is called religion. |
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wasssup1990
Nobel Prize Winner
A Land Down Under
2261 Posts |
Posted - Apr 30 2009 : 11:13:41 PM
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| I'm going to have one more try at making my own SPDIF decoder. I will use a 12 million instructions per second (MIPS) microcontroller from microchip to reattempt this. I will use assembly code only. If I achieve this, the data should be able to be played through PWM audio out of the microcontroller, assuming the microcontroller can sync-up, maintain sync and decode all at the same time. The last microcontroller I tried only did 1 MIPS, no wonder why I discovered that it wouldn't work. The bit rate is 3.072Mb/s at a 48KHz audio sample rate. |
When one person suffers from a delusion it is called insanity.
When many people suffer from a delusion it is called religion. |
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wasssup1990
Nobel Prize Winner
A Land Down Under
2261 Posts |
Posted - May 07 2009 : 11:09:35 PM
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Ok I need your opinion on something.
There will be a time delay between where the sound source outputs the sound and where the speaker actually plays the sound. Don't forget that this is a wireless digital amplifier with the ability to enhance the sound and add effects using DSP. I just need opinions on the absolute maximum delay that should occur so that it doesn't effect the listening experience. You know... A gun fires and then 10ms later you here the bang. That sort of thing. I just thought maybe someone has faced this problem before and can tell me something about this potential problem.
Thanks! |
When one person suffers from a delusion it is called insanity.
When many people suffer from a delusion it is called religion. |
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - May 08 2009 : 10:29:46 AM
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A small amount of delay will not affect low frequencies from a sub-woofer.
But adding direct sound and delayed sound causes higher frequencies to be in-phase and out-of-phase creating a comb-filter effect which is bad.
A delay causes smeared sound when the delay is shorter than an echo. |
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wasssup1990
Nobel Prize Winner
A Land Down Under
2261 Posts |
Posted - May 10 2009 : 06:33:00 AM
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| Hey thanks John for that handy information. I will definitely take it into consideration in my design. I want the best sound possible. |
When one person suffers from a delusion it is called insanity.
When many people suffer from a delusion it is called religion. |
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wasssup1990
Nobel Prize Winner
A Land Down Under
2261 Posts |
Posted - May 10 2009 : 07:02:16 AM
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Notification: The first post has just been modified. I have changed the Features and Specifications.
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When one person suffers from a delusion it is called insanity.
When many people suffer from a delusion it is called religion. |
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wasssup1990
Nobel Prize Winner
A Land Down Under
2261 Posts |
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - May 21 2009 : 09:28:29 AM
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International Rectifier has a detailed applications note with the circuit of a 200W + 200W class-D power amplifier that uses DirectFETs. There is also a follow-up applications note.
Somebody linked to the applications notes on another website (but I didn't save them). |
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wasssup1990
Nobel Prize Winner
A Land Down Under
2261 Posts |
Posted - Jun 17 2009 : 10:38:46 AM
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The mid year break is comming for me. The work load is easing.
My latest diagram:
Download Attachment:  DSS head unit layout.png
43.43 KB
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When one person suffers from a delusion it is called insanity.
When many people suffer from a delusion it is called religion. |
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wasssup1990
Nobel Prize Winner
A Land Down Under
2261 Posts |
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Home Made Advanced Digital Home Theater System
i_color01.jpg