joessportster Posted February 23, 2009 Share Posted February 23, 2009 so a friend of mine has avantgarde duo's with powered subs the sub uses a technology that is new to me you run the speaker wire from your amp into this amp (i assume there is some sort of module that takes the signal and interprets that sending commands to the plate amp) thus powering the sub i think i have this part of his system down now he is trying to tell me that on his (or any speaker system) that he can run 3 separate sets of speaker wire from the back of each channel on his tube amp and run these to each driver individually his argument is he would get better sound BLAH BLAH BLAH !!!!!!!! and that you could use a simple filter on the tweet for a cutoff point run the mid wide open, and the bass into the amp as described above my problem with this theory is 1 how would you integrate the sound, 2 wouldn't this create a load problem for the amp 3 different impedance loads coming in 3. as no 2 drivers are exactly the same wouldn't this cause differences in sound between the left and right speakers. 4 if you in theory buy into the whole cable argument wouldn't different cables (silver for highs, copper for mids, and very heavy copper for bass) with there different resistance qualities create a timing problem and last thing if this is such a good idea why did they ever invent crossovers in the first place ????????????????????? Joe Quote Link to comment Share on other sites More sharing options...
jacksonbart Posted February 23, 2009 Share Posted February 23, 2009 If it works for him, so be it, seems like overkill for the point of overkill. Quote Link to comment Share on other sites More sharing options...
philipbarrett Posted February 23, 2009 Share Posted February 23, 2009 so a friend of mine has avantgarde duo's with powered subs the sub uses a technology that is new to me you run the speaker wire from your amp into this amp (i assume there is some sort of module that takes the signal and interprets that sending commands to the plate amp) thus powering the sub i think i have this part of his system down So you take an amplified signal that by definition has had noise & distortion added through the various gain stages. You then take that signal, drop it back to line level & then re-amplify it back to where it was. The "technology" used to bring the level down is a power resisitor. Hmmm... Quote Link to comment Share on other sites More sharing options...
joessportster Posted February 23, 2009 Author Share Posted February 23, 2009 so a friend of mine has avantgarde duo's with powered subs the sub uses a technology that is new to me you run the speaker wire from your amp into this amp (i assume there is some sort of module that takes the signal and interprets that sending commands to the plate amp) thus powering the sub i think i have this part of his system down So you take an amplified signal that by definition has had noise & distortion added through the various gain stages. You then take that signal, drop it back to line level & then re-amplify it back to where it was. The "technology" used to bring the level down is a power resisitor. Hmmm... i understand what a resistor is used for but dont think it is the device used in this system (at least not for your definition above) according to my bud. the amps signal in is only used so its charteristics can be determined and that information sent on and used while powering the subs (supposed to improve the integration of sound between the subs and the horns) main question is can this be set up this way with good results and without eventual damage to the amp Joe Quote Link to comment Share on other sites More sharing options...
philipbarrett Posted February 23, 2009 Share Posted February 23, 2009 i understand what a resistor is used for but dont think it is the device used in this system (at least not for your definition above) according to my bud. the amps signal in is only used so its charteristics can be determined and that information sent on and used while powering the subs (supposed to improve the integration of sound between the subs and the horns) main question is can this be set up this way with good results and without eventual damage to the amp Joe Interesting, so there's a processor in there doing some kind of FFT? As for the speaker wiring, he is paralleling the drivers which will cause an impedence drop. For example, if each driver is 8 ohms in a 3-way box then wired this way the amp "sees" 2.6 ohms. At this point it depends on his amp's ability to drive low (and unpredictable) loads. The hi-pass capacitor will introduce a little impedence but not enough to save the average tube amp. Quote Link to comment Share on other sites More sharing options...
bhenry Posted February 23, 2009 Share Posted February 23, 2009 If the sub does not have it's own amplifier then this method is normal. As far as the rest of it.........let him have his fun and ask him if he wants to buy some swamp land from me. Quote Link to comment Share on other sites More sharing options...
JohnA Posted February 23, 2009 Share Posted February 23, 2009 What your friend is doing is normally called Bi-wiring, because you use 2 sets of wire; one for the woofer and the other for the mid/tweeter. He's going one more step and doing tri-wiring. The theory is the woofer wires carry the lows that carry the greatest power and the other wire carries the highs, seperately, reducing EM interference. For the theory to actually work, you have to have sufficient current (power) flowing to the woofer to induce reverse current (back EMF) in the speaker wires to influence the signals going to the squawker and tweeter. In a horn system, the normal current (power) levels are very small, about .35 amps. The EM field produced by 2.83 volts and .35 amps is also very small. In his case, his subwoofer amp must have power resistors to load the amp and drop the input voltage to the sub amp, only to boost it back up to drive the woofer. Logically, it cannot be anything else. His sub amp may be designed with a feedback loop that includes the woofer and corrects for unwanted cone motion. That was done years ago, too. The power resistors in the sub amp reduce the LF power and current levels to even lower values (because the main amp's power is no longer used to power the woofer), making bi- or tri-wiring positively a wretched waste of excess money. Audiophoolapathy. I would LOVE to sit and listen to a pair of Duos or Trios for a few hours. Quote Link to comment Share on other sites More sharing options...
jacksonbart Posted February 23, 2009 Share Posted February 23, 2009 This tool almost always solves friendly or unfriendly arguments. Quote Link to comment Share on other sites More sharing options...
joessportster Posted February 23, 2009 Author Share Posted February 23, 2009 What your friend is doing is normally called Bi-wiring, because you use 2 sets of wire; one for the woofer and the other for the mid/tweeter. He's going one more step and doing tri-wiring. The theory is the woofer wires carry the lows that carry the greatest power and the other wire carries the highs, seperately, reducing EM interference. For the theory to actually work, you have to have sufficient current (power) flowing to the woofer to induce reverse current (back EMF) in the speaker wires to influence the signals going to the squawker and tweeter. In a horn system, the normal current (power) levels are very small, about .35 amps. The EM field produced by 2.83 volts and .35 amps is also very small. In his case, his subwoofer amp must have power resistors to load the amp and drop the input voltage to the sub amp, only to boost it back up to drive the woofer. Logically, it cannot be anything else. His sub amp may be designed with a feedback loop that includes the woofer and corrects for unwanted cone motion. That was done years ago, too. The power resistors in the sub amp reduce the LF power and current levels to even lower values (because the main amp's power is no longer used to power the woofer), making bi- or tri-wiring positively a wretched waste of excess money. Audiophoolapathy. I would LOVE to sit and listen to a pair of Duos or Trios for a few hours. i have done bi wire set ups b-4 but i always used a seperate amp . jacksonbart thanks for the laugh sometimes i do want to crack him in the head but this one is just a friendly dis-agreement Joe Quote Link to comment Share on other sites More sharing options...
philipbarrett Posted February 23, 2009 Share Posted February 23, 2009 In his case, his subwoofer amp must have power resistors to load the amp and drop the input voltage to the sub amp, only to boost it back up to drive the woofer. Logically, it cannot be anything else. According to the OP this is not the case. I think it must be some kind of unity gain buffer similar to the Musical Fidelity 550 Supercharger design. Interesting things these buffers, Pass Labs has some designs using this type of current gain which basically matches your preamp to your speakers. AudioExpress had a feature on this type of design last month. Quote Link to comment Share on other sites More sharing options...
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