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sub cutting in and out, gain related???

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sub cutting in and out, gain related???

  • my sub is a alpine SWR-1243d (dvc 4 ohm sub, 600w rms)

    my amp is an alpine mrp-m500

    old piece of junk sony xplod HU

    the power and ground wire are 8 gague.

    ive had this system in my car for about 6  months now, however at first i had one of the older SWR-1242d type r's. for about the first  4 months, then i upgraded to the new 2010 model of type r like 2 months ago. 

    my gain has always been set at 75% (or 3 oclock), i keep my low pass filter at 80, and my bass eq has always been set at +4 db. and i had never touched any of these settings because it was perfect like that. 

    anyhow about a week and a half ago i was on the way to a buddies house and the sub just quit playing, upon getting to his house i checked in my trunk and the amp was still on, just no sub. the next day when i left for work it was working fine again, however upon turning it up and letting it play loud after about 2 minutes tops it cut out on me again. and it seems that when i turn the volume down the sub will cut back on. (sometimes not though, sometimes it wont come back till the next day, a few hours, etc.) 

    anyhow  this morning before leaving to work i turned the gain  from 75% or 3 oclock down to about 2 oclock and also turned my bass eq down a little tad as well,  and on my way to work i turned the volume up loud to where i normally would have it when i would be poundin' before my problem arose, which is about just over half volume. and it didnt cut out on me at all, or on my way home, either. so when i got home i turned the gain and bass eq back to where it was set and turned it up and sure enough it cut out on me.

    so im wondering why after 6 months of no problems whatsoever and not touching it the gain, or any setting on the amp, it is all of a sudden too much for the amp and/or sub to take? i dont want to have to leave the gain turned down as low as i had it earlier when it was working fine because when it is set that low it hardly even hits and that is just unacceptable for me. so anybody have any ideas here? i am greatly appreciative of any input, thanks!



    [edited by: J P at 2:46 PM (GMT -5) on Sat, Oct 16 2010] Changed to discussion.
  • sounds like to me ur amp cant pull enough power from the battery cauz ur power and ground are to small of guage not letting it suck as much as it needs for 600 rms i would have 4 guage power and ground. not 8.  sounds like to me it cant pull the true power it needs. sounds like a pretty good guess to me mabey someone else can help here. but if it was me thats the first thing i would change. just saying..

    Alpine CDA-9825, pioneer 5 1/4s, Kenwood 6by9s KFC-6909S, 2 12in Mtx terminators TNP212D, Mtx terminator amp TN250/1, Jvc 2 channel amp KS-AX3002, Jvc 2 channel KS-AX4302, 1 sound led reactive light

  • zdub2004 is probably right it may have worked fine for a while just because it clean and pure 8 gauge. check the wires for corrosion/ rust. but your best bet would be replacing the wire with 4 gauge. if you do decide to do that pick a 4 gauge kit from crutchfields signature series i think they only have one for like 130 bucks but you can return it a full refund within 60 days which give you plenty of time to make sure it is functioning properly (everything else is 30 days).

    feel free to ask me anything

    robert 

    GMC Sonoma, JVC KD-A95BT, 2 Pioneer TS-D601P in doors, 2 Pioneer TS-G4644R in dash, 2 JL W3v2-D2 10 inch subs, Lightning Audio B4.250.2, Soundstream TX1.1300D

  • hate to say this but i had the same problem with my amp and i figured out that a channel had started to go bad. the only way to fix this is to get a new amp. also if u can buy a 1.0 farad capacitor to lighten the electrical load. that is one reason subs/amps go out so quickly. people turn them up really loud then expect them to last forever. it just dont work that way.

  • personally i would not recommend the capacitor if you have a stock electrical system they tend to actually decrease you battery life because they pull power for a little while and then stop then use the energy it has pulled and then recharges again check this link. they really are just a waste and cause more harm then good. and i doubt that the problem is the channel going bad that really does not explain why lowering the gain would cause the sub to work. if a channel is going bad it would cut in and out no matter where the gain is set. but even if that is the problem you really should upgrade to 4 gauge wire the general rule of thumb is...

    0-500 watts= 8 gauge

    500-1000 watts= 4 gauge

    above 1000 watts= 0 gauge

    GMC Sonoma, JVC KD-A95BT, 2 Pioneer TS-D601P in doors, 2 Pioneer TS-G4644R in dash, 2 JL W3v2-D2 10 inch subs, Lightning Audio B4.250.2, Soundstream TX1.1300D

  • i had considered maybe it was the channel until today when i realized that it does not have any problems with the sub cutting out unless the gain is up where i would like to have it set, anywhere lower works like a charm.

    alright well i agree with all of you, when i bought the 8 gauge wire i took into consideration the wattage rule of thumb but with my amp being 500 rms (probably even a little more) i figured i would go for cheap and try to get away with running 8 gauge, seemed to work great for a while but i did not take into consideration corrosion on the wires and whatnot. so ill take your advice and replace the power and ground with 4 gauge and see how it goes from there.

    thanks again guys!

  • The amp should only draw 45A at clipping.

    8-gauge should be fine.  4-gauge can't hurt anything, but it's probably not the magic fix either.

    I disagree with the capacitor statement (the waste comment), but they are mostly for lights dimming or for voltage drops when the bass hits.

    The amp is mono, so it can't be a channel going out - although it could be a pre-amp circuit channel going bad or general amp problem.

    The sub could have some different impedance setting from the old sub and require a different gain setting, but it should hit about as hard.

    Any chance of the sub not being broken in yet?

    Otherwise, I'm thinking it might just be the amp getting old and not putting out as much power as it used to.

    Hope This Helps!!!

    Anyone else have suggestions?

     

    2002 Ford Focus JVC KD-A815 Sony CDX-GT410u Sony XT-100HD HD Tuner Stock speakers, no amp, no subs

  • TigerHeli the problem with a cap on a standard stock electrical system it has the same effect on a battery as starting and shutting off your car. thats why i don't recommend it. it may be a quick fix for dimming lights and such but in the long run it will destroy your battery. they are just a bad idea unless you spend the extra cash on a new alternator, battery, the big three, and add an addition battery. oh and a battery saver.



    [edited by: BIG teddy at 8:39 PM (GMT -5) on Tue, Aug 24 2010]

    GMC Sonoma, JVC KD-A95BT, 2 Pioneer TS-D601P in doors, 2 Pioneer TS-G4644R in dash, 2 JL W3v2-D2 10 inch subs, Lightning Audio B4.250.2, Soundstream TX1.1300D

  • TigerHeli i doubt it would be because of the sub not being broken in because the new one ran at the same settings as the old one for a month and a half

    GMC Sonoma, JVC KD-A95BT, 2 Pioneer TS-D601P in doors, 2 Pioneer TS-G4644R in dash, 2 JL W3v2-D2 10 inch subs, Lightning Audio B4.250.2, Soundstream TX1.1300D

  • BIG teddy
    TigerHeli the problem with a cap on a standard stock electrical system it has the same effect on a battery as starting and shutting off your car. thats why i don't recommend it. it may be a quick fix for dimming lights and such but in the long run it will destroy your battery.

    Logically, I am not seeing this - the cap is an electrical storage device - very similar to a battery, actually, except it charges and discharges quickly.

    The ONLY effect it should possibly have on the battery would be if the alternator were totally overwhelmed and the battery was having to charge the cap - even then the cap would only charge to the level of the battery.

    Now if you are saying the cap puts an additional load on the alternator and could do more harm than good to it, I could maybe buy into that a little more.

    I think the biggest issue is people install 2000 W RMS amps and then think a 0.5-Farad cap will solve their electrical problems and it can't.

    2002 Ford Focus JVC KD-A815 Sony CDX-GT410u Sony XT-100HD HD Tuner Stock speakers, no amp, no subs

  • The main reason someone will put a cap on a vehicle is to help with voltage drops and lights dimming and yes the cap does put an additional load on the alternator which usually does cause it to drain power off of the battery (guess I should have worded it better). When you are having voltage drops and dimming lights it is because your current draw on your alternator exceeds what the alternator can produce. 

    Hope that makes better sense.

    Robert

    GMC Sonoma, JVC KD-A95BT, 2 Pioneer TS-D601P in doors, 2 Pioneer TS-G4644R in dash, 2 JL W3v2-D2 10 inch subs, Lightning Audio B4.250.2, Soundstream TX1.1300D

  • We're thread jacking the topic, but ....

    I'm still not buying into the cap killing the battery thing.

    Here is my take on it:

    Stock electrical - the alternator supplies up to 100A and generally ouputs 14.1V to run the lights and charge the battery.  The battery outputs 12.6V with the engine off.

    You add a 1500W amp - The amp draws 136A at clipping when the bass hits which is more than the alternator can supply - especially with the combined load of the vehicle electrical.  The voltage would be expected to fluctuate between 14.1V when the bass is not hitting and maybe 11.5V when the bass hits.  Ideally, you would want a HO alternator to fix this, but that's expensive for something that is only a problem when the bass hits, and also the alternator really only kicks in when it senses a load, so I'm not sure how well it would take care of a dimming lights problem.

    You add a cap to the above system.  The cap discharges when the bass hits and charges when it is not hitting.  Overall, the voltage probably stabilizes around 13.5 or so volts.  The battery would be fine as it is ALWAYS seeing more than charging voltage.  The alternator on the other hand is pretty much constantly running b/c it has to power (make up the drain) from both the cap and the amp.  However, it sees a constant load rather than spiking dips - so maybe that helps.

    Anyway - that's my take on it ....

    Hope This Helps!!!

    Anyone else have suggestions?

     

    2002 Ford Focus JVC KD-A815 Sony CDX-GT410u Sony XT-100HD HD Tuner Stock speakers, no amp, no subs

  • i dont think a cap would help my problem, because ive never had any problem with dimming lights or anything, even when i would let it pound.

  • rizzle425
    i dont think a cap would help my problem, because ive never had any problem with dimming lights or anything, even when i would let it pound.

    Agreed - I think cap's can be useful (some members disagree - on this and other forums and that's fine too), but I don't think it would make a difference with your problem ...

    Hope This Helps!!!

    Anyone else have suggestions?

    2002 Ford Focus JVC KD-A815 Sony CDX-GT410u Sony XT-100HD HD Tuner Stock speakers, no amp, no subs

  • hm. so the other day after getting off work i stopped by a local car audio shop and asked them about their 4 gauge wire and kind of explained what my problem was. before the guy even really did any analyzing he asked what amp i had and upon telling him what kind it was he instantly told me that my problem was the amp. he said that he had seen multiple instances of people coming in with the same problem, and the same amp, and it was the amp every time. i did buy the amp used off of ebay so theres no telling what kind of abuse it was put through before i got it. and the amp does seem to get REALLY super hot after a while, like too hot to touch even for a few seconds, ive always had in the back of my mind it may be going into protect, but it will do it even when the amp isnt hot.. have you guys heard anything about this particular amp having any issues? this guy was dead set that it was my amp, i explained to him i had 8 gauge wire and that it may just be too small, but he said that gauge of wire should be fine and kept insisting that it was the amp.

    but then again , the particular shop i went to doesnt sell alpine products, only kicker and jl and rockford fosgate, and i remember when my brother in law was doing some shopping for his system the very guy i talked to was bashing on alpine. so im kinda wondering if maybe he was just saying that because he doesnt like alpine and wants me to buy a new amp from them?

     

    oh yah and yesterday i noticed where my power cable connects to the battery terminal the wire was a little loose, and after i tightened it up real nice it had made my sub come back, so i thought o maybe that was my problem (as i had done 4 or so times trying to fix this issue) but sure enough not even a half hour later when i got in my car the sub cut out...again. though after tightening the wire i did notice that it will play for a longer period than it used to before the sub cuts off. im starting to run out of ideas here..