BAD AMP???

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BAD AMP???

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Got a PX-1000  4 Crunch amp 6 months old that went dead on me. Sounded perfect the day before. I used my test light and it had power going into the amp but the power light aint on. Fuses were ok too. You know if it has a reset somewhere on it ?-Thanks for any good suggestions..

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  • Based on the information you posted in another thread praising this amplifier, I suspect you may have wired things up incorrectly and may have damaged the amp. Not to mention you are misinformed about the true abilities of the amplifier, Crunch WAY over rates their gear. You'd be lucky to get 500RMS in total output, meaning 250RMS from the front channels bridged and 250RMS from the rear channels bridged into a 4 ohm load. You mention bridging the amp and wiring speakers in parallel to it, which if you really did such, that's a 2 ohm load and would eventually damage the amplifier.

    Anyways, lets start fresh.

    Make/model/year of vehicle?

    Model numbers of all equipment used in the car?

    How is everything wired?

    Where is the amplifier grounded?

  • Weigle, Thanks for responding to my question. As for what my system is in it's a 2006 super crew f- 150 Ford I have a Pioneer DEH- X 6900BT with the Crunch PX- 1000 4 channel amp. I put JBL 5x7 in all four of my doors.   I got a 8 gauge kit with the equipment for my hookup. Used Suncoast Sound in Monroe La to install it. Got a long story about what all happened right off the bat with them. Won't ever use them for anything else. When they gave the truck back I put a CD in and noticed I only had front speakers playing. They took it to the back again and fixed it. It lasted for two days and went back to only the front speakers playing' So I took it back once again and this time they told me my RCA jacks on my tape deck were bad. The owner said it was a one in a million chance of that happening. So I took my deck out and sent it back to Amazon. Got a deck just like it and got them to hook it up "for another 100 bucks" and guess what Same thing Back speakers won't play. One in 2 million chance I guess. This time he tells me my back speakers were blown Wrong. After buying another set and them not working he told me I needed a deck with 3 sets of RCA Jacks That's what I got and I finally got to enjoy music in my ride. Was told by another shops hand that hooking both front together and both rear together would double the speaker output.Thats 250 watts times 4 channels or 500 apiece x 2 channels. Got louder and clearer to me. but I aint know expert or I would have hooked it up myself. Think my biggest mistake was putting my amp under the front passenger seat. Was just to hard to adjust without taking the seat out but I'm ok with it now though. Do you know anything I could check to get my stereo going? Let me know. Thanks!!!

  • Sorry to hear of the poor experience you received with the install shop.

    Knowing what you've said now, it really makes one's imagination go wild thinking of all the corners they may have cut.

    Do you have a subwoofer setup in your truck? I see no mention of such and that makes me really wonder why they insisted a HU with 3 set of preamp outputs be used.

    And the other shops hand may have been under the wrong impression, given the equipment you have. The Crunch amp you have has the following "claimed" power output, 125x4@4 ohms, 250RMSx4@2 ohms, or 500RMSx2@4 ohms.

    Wiring the speakers together will drop the load in half, so if they are 4 ohm, then it'd be 2 ohm, amp will double it's power output, but you have two speakers the power is divided between, so no difference really.

    If you, or someone, wired two speaker in parallel for a 2 ohm load, but then wired them to the amplifier in bridged mode (which is only stable down to 4 ohms) then the amplifier would attempt to produce more then 500RMSx2, which that would definitely be more power to them, while the amp works.

    Now, that amplifier isn't actually going to produce it's claimed output, it's just not possible due to physics.

    With a 14.4V input (typical charging system voltage) and 60AMPS of fusing, the amount of power capable of being produced is 864W with a 100% efficient amplifier (which don't exist yet). That amplifier used class AB circuitry, which tends to be 50-60% efficient. Assuming 60% efficiency, that's 518.4W, which that power would be total, so 259.2W for each bridged set of channels or 129.6W per channel if ran at 2 ohms.

    So, now that we know a bit more information, lets see if we can get this figured out.

    Try unhooking everything from the amp, RCA cables, speaker wires, power, ground, remote lead, everything. This will be the closest thing to a reset as you'll get, as all the internal components of the amplifier will discharge over time while unhooked.  So, just leave the amp sit while we test some wires.

    Now, if you have a DMM, check the voltage on the power wire. Using a test light merely says there's power, but that could be 1.7V for all we know. Should be getting 12V+ with the truck off and 14V+ with it running.

    If such checks out, check the remote lead for power, should have 12V with the stereo on.

    Also, where is the amplifier's ground secured at on the truck?