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4ch amp help

Discussion in 'Car Audio / Security / Electronic Accessories' started by AHHVTEC, Dec 24, 2011.

  1. Dual-500

    Dual-500 Well-Known Member VIP

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    ^ That will help. You are on the right track with it.
     
  2. lostsoulzprophet

    lostsoulzprophet delslow

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    just bring it all to my house in ga and we can tackle that beast. lol
     
  3. Dual-500

    Dual-500 Well-Known Member VIP

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    That's a good plan! Bring it by my place and we can hook the amp up to a dummy load and see exactly what it's made of......

    [​IMG]

    Then we'll do the install and RTA it with some pink noise and setup the crossover, amp gains, and eq:

    [​IMG]
     
  4. CAFROG

    CAFROG Honda Minion VIP

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    I didn't go to the link...:fuckyou2:

    Two subs that are 4ohm ran parallel.....There are Very few amps that claim its okay to run 2ohm bridged stable. Its like running Nitrous on a stock block.....its fun and do-able but still risky.
     
  5. Dual-500

    Dual-500 Well-Known Member VIP

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    There aren't that many amps out there that can handle a 4 ohm load when bridged. I don't see anywhere it mentioned running the 10's in parallel with one another.

    I'm still wondering if the amp can handle a 4 ohm load bridged mono into a 2 ch configuration. That will be effectively running the channels into a nominal 2 ohm load and that's a tall order to fill.

    I'm running one of these: Audiobahn A2601Q 150W x 2 Car Amplifier at Crutchfield.com

    Into a pair of 4 ohm 12" subwoofers, it nets a real 150w RMS continous per channel and is rated to handle 2 ohm loads - it also has forced air cooling.
     
    Last edited: Dec 26, 2011
  6. AHHVTEC

    AHHVTEC Well-Known Member VIP

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    well guys i was not correct lol. i looked at them tonight he has 2 amps one is a 1500 watt 4ch majestic amp and the other is a 2ch 820 watt power acoustic. if the 820 dosent work i will just make him buy a new 500 watt amp
     
  7. Dual-500

    Dual-500 Well-Known Member VIP

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    ^ That's a little extreme for 150w rated drivers. I would suggest instead of downgrading the amps, upgrade the woofers.
     
  8. AHHVTEC

    AHHVTEC Well-Known Member VIP

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    yeah but new amps are under 100 bucks lol i figured the 820 2ch would be ok with the gain all the way down, i doubt its true watts
     
    Last edited: Dec 26, 2011
  9. Dual-500

    Dual-500 Well-Known Member VIP

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    It should be perfect with the gain wide open or matched to the volume control and loudness compensation.

    K & T Sales: Shop - Amplifiers - Power Acoustik OV2820
     
  10. AHHVTEC

    AHHVTEC Well-Known Member VIP

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    cool, so lets just hope that ollld 820 still works then.and just run them at 4ohm correct ?
     
    Last edited: Dec 26, 2011
  11. FLounder

    FLounder power hungry VIP

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    ive been running a 1200 watt power acoustik amp for about 7 years now, still going strong.
     
  12. Dual-500

    Dual-500 Well-Known Member VIP

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    Yes.
     
    1 person likes this.
  13. CAFROG

    CAFROG Honda Minion VIP

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    I've personally blown two power acoustic amps in my time but I still think they as a decent amp for the price.

    But any amp that cost $0.25 or less per watt is gonna give you what you bought. :shrug:
     
  14. AHHVTEC

    AHHVTEC Well-Known Member VIP

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    yeah, back in the day i remember loving this kind of stuff i was running 2 RF punch power hx2 with a bd1000 RF amp and it was beast lol, it came with a spec sheet showing it was actually putting out more than 1000 watts. but damn was that shit high i think for the subs box and amp it was over 2 grand
     
  15. Dual-500

    Dual-500 Well-Known Member VIP

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    Here's what $1.15 a watt (8 ohm load) would buy in 1978:

    [​IMG]

    Built for the elite class extreme audiophile or professional sound reinforcement use. Stable at 2 ohm loads, conservatively rated at 800w RMS per channel into a 4 ohm load.

    This one is mine, pending restoration. When restoration is completed it will be put into service in my HT/Music system driving JBL 2245 18's below 200hz.
     
  16. Dual-500

    Dual-500 Well-Known Member VIP

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    ^ yep. That's a good rule of thumb.

    Most amps are fused less than what it takes to output rated continous power. They are fused for music amplification. To perform continuous sine wave testing on most amps, the power supply fuses need to be swapped out for larger capacity fuses.

    Music has a peak to average ratio of roughly 10:1 So, amps are typically fused to ourput short term power levels that are above the continous rated power level. This is called headroom or peak power. A good amp will have 2db or more dynamic headroom. A good 100w per channel amp, will have a short term peak output of 150w or more per channel.

    Amps are ~70% efficient. So, output power will always be less than input power. The power lost is in the form of heat.
     
  17. AHHVTEC

    AHHVTEC Well-Known Member VIP

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    ok guys have an update and little problem, got all this installed today and every thing went smooth and for about 10 min i guess the subs was doing work and hit much harder than i expected with the levels less than half way up. but here is the problem, ok everyone knows the sound the subs make when you first turn them on,that ba doom sound of the subs when the power gets to them, ok i expect that when i cut them on, but the thing is now with the amp barley tuned up at all, or when the stereo volume level is at 0 it makes that sound over and over and over, and the only way i can make it stop is if i have the amp all the way down and the volume is up over level 1. i also noticed it only does this in the low and full mode, high mode its fine but more than just bass comes through the speakers in anything other than low mode. and if i remember correct low mode is where it needs to be anyways. so why is it going ba doom over and over, is it a bad amp or is it me lol
     
  18. Dual-500

    Dual-500 Well-Known Member VIP

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    Jeez. That in the old school world all the back to tube amps and early transistor was called "Motorboating". When the system goes into a low frequency oscillation.

    Motorboating can be caused by a myriad of things. Bad amp, bad cables, bad pre-amp (head unit) etc.

    It can also be from inadequate wire size feeding the amp. When it powers up the surge causes a voltage drop in the system and there is a potential for a DC voltage offset between the amp and the head unit. The amplifier could be reacting to the DC offset.

    Larger wire, new battery, charge battery, install filter capacitor at the amp would probably be what I would try first.
     
  19. AHHVTEC

    AHHVTEC Well-Known Member VIP

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    yeah i told him just buy a 2ch 600 watt amp, best buy seems to have a good bit of those for under 100 bucks, like planet audio, and a few others, so im gonna try that.
     
  20. CAFROG

    CAFROG Honda Minion VIP

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    Power wire is crossing swords with the RCA's somewhere??
     
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