Another IDMAX ?
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Gold Member Username: Basshead86Ocala, FL USA Post Number: 1446 Registered: Aug-05 | This pertains to my amp, which is a Class A/B, and my IDMAX's power handling capabilites. I have read that it is better to run an A/B amp at a lower ohm load(2 instead of 4, 1 instead of 2), b/c it makes more heat trying to waste the extra power not used, than getting rid of all the power it creates through the output stage(speaker terminals). so, going on that: would i be better off to get a DVC 4 ohm IDMAX, running my DLS A6 at 2 ohms to produce 870wRMS? or get a DVC 2 ohm IDMAX, running my DLS A6 at 1 ohm to produce 1200wRMS with a little extra headroom (and supposedly better for the Class A/B amp). |
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Silver Member Username: Riebread77Post Number: 655 Registered: Jun-05 | anytime you lower the impedance, you lower the amount of resistance. When you lower the amount of resistance, you get more heat. When you get more heat, you get more distortion...4 ohms is optimal. |
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Gold Member Username: Basshead86Ocala, FL USA Post Number: 1458 Registered: Aug-05 | "Efficiency: What makes an amplifier get hot? Both the power supply and the power amplifier generate heat. The maximum efficiency of the power supply is nearly 100%. Good power supply designs, with the highest quality components approach 85%. The class AB amplifier efficiency at full power can approach 75%. The total efficiency, including the power supply, can be about 65%. But, efficiency drops at lower power and can typically be under 20%. A class AB amplifier actually runs cooler at full power than it does at half power. Run this amplifier into clipping and it might run even cooler! Where is all this power going? The output transistor is basically a large variable resistor. If the instantaneous output voltage should be 40 volts and the power supply is 100 volts, then 60 volts must be "wasted" in the output transistors. Driving a reactive load (like a speaker) causes the efficiency to drop ever further. This brings us to the other audio classes designed to improve efficiency." Courtesy of GlassWolf that is where i got that idea from. so there must be some validity to running it at 1 ohm.  |
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Gold Member Username: Basshead86Ocala, FL USA Post Number: 1460 Registered: Aug-05 | bump |
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Gold Member Username: Basshead86Ocala, FL USA Post Number: 1466 Registered: Aug-05 | bump....dangit! |
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Silver Member Username: RovinTrinidad & T... Post Number: 746 Registered: Jul-05 | Told ya this forum is slooow today - posts are almost far apart as an hr . Now thats quite a dilemma - but i'd gather just by looking @ the amt of headroom the amp has @ 1ohm (@ least 300wrms) ,i'd get the 2ohm version sub .... here is a link to his amp in case anybody wondering http://www.dls.se/english/fstark/a6n.htm |
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Gold Member Username: Basshead86Ocala, FL USA Post Number: 1482 Registered: Aug-05 | i think.....i'm not sure, that's why i posted this ?, but nobody seems to want to help me.*cough GW-Jon cough*. lol i am sure that it doesn't need more than 800wRMS, but after reading GW's info on his website, it seemed like a good idea to run my amp Class A/B amp at a lower ohm load allowing it to get rid of all of the power it produces so it doesn't get so hot, instead of letting it waste it in the output transistors. |
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Gold Member Username: Jonathan_fGA USA Post Number: 4808 Registered: May-04 | His statement above doesn't imply to run a lower impedance, he'll tell you that. Voltage will remain constant with different impedances, it will be x at maximum output regardless (unless you're talking about a regulated amp, such as the JL amps, that switch voltage rails in order to produce constant power in relation to impedance). The voltage drop he mentioned above is across the output stage of the amplifier, and as the transistors enter saturation there is little difference in voltage between the collector and emitter, so little voltage is dropped and little heat is dissipated. This is the operation of the transistors, not the load upon them. Power is the only reason to run a 1 ohm load. Everything else suffers. |
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Gold Member Username: Basshead86Ocala, FL USA Post Number: 1488 Registered: Aug-05 | thanks Jon. |
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Silver Member Username: RovinTrinidad & T... Post Number: 749 Registered: Jul-05 | Er - so that means he should get the 4ohms version instead ??? |
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Gold Member Username: Basshead86Ocala, FL USA Post Number: 1489 Registered: Aug-05 | yeah. |
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Gold Member Username: Basshead86Ocala, FL USA Post Number: 1517 Registered: Aug-05 | I LOVE IDMAX!  sorry, i just had a rush of emotion. LOL |
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