18th July 2007, 20:10
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| Senior - BHPian  | Quote:
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18th July 2007, 20:53
| #17 | |
| Senior - BHPian  Join Date: Mar 2007 Location: Bangalore
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18th July 2007, 21:04
| #18 | |
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But: Open voice coil has nothing to with the amp - no connection. Forget amp Q. My surmise was the effect on the mechanical system by the shorted-coil sub-system (2nd coil traverses magnetic field, current generated in coil, causes magnetism in other direction, acts against the main coils' motive force. Ergo, damping). I couldn't see the connection between the (isolated, shorted) 2nd coil and the driver's Qes, which is linked with the main current carrying coil.  | |
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18th July 2007, 23:33
| #19 | ||
| Senior - BHPian | Quote:
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BTW, that is leading me back to basics- any conducting object moving in magnetic field should give rise to damping effect... that means speakers with metal formers should have its own damping effect. Anyway, everything should indirectly get factored in the Qms. AFAIK, the same principle is used in eddy current braking, also seen in fitness bikes/ellipticals which claim smooth & silent "magnetic" technique instead of belt-friction. Last edited by santosh.s : 18th July 2007 at 23:35. | ||
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19th July 2007, 07:05
| #20 |
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19th July 2007, 10:55
| #21 | |||
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The alu former is 1 shorted turn effectively, and the damping, though non-zero, is but insignificantly finite compared to the large motive force of the voice coil. Shorting the second coil, which has same number of turns as the driven coil, is producing significantly more damping (the magnetic field of the 2nd coil is much much weaker than BL so they don't totally cancel out; also, it is complex interplay, the waveforms will not synchronize time-wise, 2nd coil is lagging). Quote:
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19th July 2007, 11:06
| #22 | |
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Bridging 2 channels of 55W rms nominal will produce 110W rms. Even though this is looks low compared to the 400W rms of the sub, it will produce substantial thump. 400Wrms is "nominal power handled" and will produce a really big THUMP if driven at that level. But, since your ears' ability to differentiate power is logarithmic, you will not notice the difference in the car normally, the bystanders outside would. Now who are you playing the music for? If only for yourself, it is not bad. If it is for others, maybe a monoblock 300Wrms would be better. 600Wrms in moderation (whatever that means to you) EVEN better - but might fry your sub if you are pushing 1000W peaks too often. Your choice. I would recommend doing it step by step and stopping when you are satisfied with the loudness levels. The 2 ohms resistor will only warm the interiors of the car, but not produce any sound, sir. Last edited by DerAlte : 19th July 2007 at 11:08. | |
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19th July 2007, 11:18
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| Senior - BHPian  | Quote:
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 Der Alte - Think opposite of what Navin posted, more specifically on the lines of "Black" & "Berry"  And needless to say the Old Man of ICE has a very wicked sense of humour!! | |||
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19th July 2007, 11:59
| #24 | |
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Last edited by navin : 19th July 2007 at 12:07. | |
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19th July 2007, 12:08
| #25 | |
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Wicked? I thoight it was just plain warped. esp if I use Hindi. | |
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19th July 2007, 12:10
| #26 | |
| Senior - BHPian | Quote:
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19th July 2007, 12:17
| #27 | ||
| Senior - BHPian | Quote:
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You forgot to say "Elementary, my dear Watson", Ishaan  | ||
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19th July 2007, 13:24
| #28 | |
| Senior - BHPian | Quote:
55 x 4 at 4 ohms 110 x 2 at 8 ohms 220 x 2 at 4 ohms 440 x 2 at 2 ohms but in this world nothing is perfect . as the output section is weak or the power supply section is weak which makes them lose the output...but here is a example of a solid amp... Gt-trading - Attivitą Power 4 ohm stereo Watt RMS - 11 to 14,4 Volt -> 50 x 2 Power 2 ohm stereo Watt RMS - 11 to 14,4 Volt ->100 x 2 Power 1 ohm mono Watt RMS - 11 to 14,4 Volt -> 200 x 2 Power 0,5 ohm mono Watt RMS - 11 to 14,4 Volt -> 375 Power 0,25 ohm stereo Watt RMS - 11 to 14,4 Volt -> 700 Power 4 ohm mono Watt RMS - 11 to 14,4 Volt -> 200 Power 2 ohm mono Watt RMS - 11 to 14,4 Volt -> 400 Power 1 ohm mono Watt RMS - 11 to 14,4 Volt -> 750 Power 0,5 ohm mono Watt RMS - 11 to 14,4 Volt -> 1400 | |
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19th July 2007, 14:14
| #29 | |
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Power, P = (Voltage, V)^2 / Resistance, R. Since you are getting a constant voltage in the car amp (might vary from 11V to 14.4 volts.. but for our theory sake lets take it 12V), you get a varying power output for different resistance (R) that is connected to it.. When you bridge the channels, you are basically doubling the available Voltage (eg. +12V to -12V). When applied to the above formula you get P = (2V)^2 / R ==> P = 4 V^2/R ==> P = 4 P0 where P0 is the initial power output... So there you go.. in theory you get 4 times the power output than from a individual channel. But like LBM has mentioned but in this world nothing is perfect . | |
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19th July 2007, 19:50
| #30 | |||
| Senior - BHPian Join Date: Mar 2007 Location: Bangalore
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You *should* have tried it in Hindi. PinkMango would be an Open Source, Linux based device Quote:
Without insulation that makes it 1 single shorted turn (even if you assume separation, it assumes insulation). And not current carrying capacity, but instantaneous current produced by the magnetic field traversal. The alu former's current capacity is quite large (check longitudinal cross-section area of the former) * The voltage produced by mag field traversal is proportional to the LENGTH of conductor in the mag field (hence number of turns) and speed of traversal (technology of old electric cigarette lighters, long before quartz-based ones) * The current in the coil is proportional to this voltage, the motive force applied and the load: the principle of electric generators * When shorted, the load is the effective resistance of the coil itself Exact inverse of this is Motors (that's what drivers are): push current through a coil by applying voltage, which produces a magnetic field, which pushes against the mag field of the magnet and pushes the cone. Greater the dv/dt or di/dt, faster the deflection (the battery test). Quote:
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