Sub Or Amp problem???

[calais_cruzin]

Hey All,

Just have a problem with my amp or subs that has just happened in the past 4 days

What happens is volume on 22 is fine but put up to 23 n i loose a heap of bass. My subs used to crank to around vol 27/28 b4 they peaked

Ive checked all my grounds n power, thinkin that it was unable to ground out properly once on this volume.

Put multi-meter on it n she reads perfect, 12.4 off, 14.3 on, and only loose's around 0.2v wen pumping

Ive got a JBL 75.4 520w amp running 2x JBL 12inch 250rms subs bridged.

I have no idea y this problem has started, cept that i did overheat the amp bout 2weeks ago on a long drive.

The problem has only started on fri night as i noticed it sounded distorted at a level it should be smooth.

I turned me gain down a bit thinking it may have worked its way up a bit but still no change.

Im stuffed if i can think of wats goin on.

Any help would be great,Thanks

Also what sends the signal for vol control from H/U to amp.

[calais_cruzin]

Goin to go get a Jaycar capacitor the sarvo, but i doubt it will change anything.

Its just weird that this has happened all of a sudden.

[calais_cruzin]

Cap has fixed the problem, dunno how but it has.

Also the dude at jaycar said there caps have a beep that goes off while it charges, it dont beep.

Has anyone else got a response capacitor from jaycar???

Im sure its all wired up right, batt + to + on cap then + from cap to amp, and cap - to chassis, got amp earthed to same spot as cap but on a different wire, amp not earthed thru cap.

[05 VZ SS]

Yeah, on got 1 the other week. Guy in jaycar said to stop the beeping, just pull out the speaker and it won't damage your warranty. I got them to do it..But the beeping was real annoying. Now it doesn't beep at all....
Which one did you get? I just got the 1 Farad one...

[calais_cruzin]

Yeah i just got the 1farad cap, but mine dont beep like he said it would.

What hole did u put the batt power into, i put mine in the big 2guage hole, then ran power to the amp from the 4gauge next to it.

[05 VZ SS]

i put mine in the 4gauge hole...cause the bigger hle was 2 big.....and then doubled up a 8 gauge wire 2 power 2 amps...If thats makes sense...

[calais_cruzin]

Yeah that makes sense.

So ur useing the hole on the bak n one on the side.

Wonder if thats the reason it beeps, coz im just using the onse on the sides, n im not getting the beep like he said it would.

Im happy with it, glad i dont have to take out the pretzo thingy to stop the beeping.

[05 VZ SS]

thats not the reason it beeps. When I first used it, it was beeping...Really annoying and loud....There's a new version and an old version..I think the new one is the squarish design one, not the big cylindrical one...And the square one beeps...The old one doesn't...

[calais_cruzin]

Yeah mine is the square one, I think the model by memory is RU-6752.

But i was pointing more towards using the back hole as the batt + to be a reason y urs beeped n mine didnt.

Jaycar explained what i would need to remove to stop the thing from beeping when it charges but mine hasnt beeped. weird eh

[Joe Peeps]

Just curious what made you go get a cap, cause i can think of no reason how it would be fixing the problem you describe......... if someone can, please enlighten me

[calais_cruzin]

i was wanting to get a cap anyways, but wen i hooked it up i went over everything again making sure it was all good no loose wireing.

and yeah its all good now, so probly got nuffin to do with the cap, but it has stoped teh slight clip i was getting

[05 VZ SS]

Yeah, that it weird it din't beep...When I went to Jaycar and he told me it beeped(ps we have the same cap) i was thinking, oh it an't be that bad can it...got home plugged it up..beep beep beep...thought bugger that..went back to the stroe so they could rip it out, and we tried another one and it beeped too..So yeah, yours is weird...Unless yours was a returned one that had the speaker removed already!!!

[Phreddy]

Hey Guys.

Just had a peek at this thread - it sounds to me like you might indeed have a voltage drop problem there 'cruzin. I note that you mentioned you metered the supply voltage to the amp, but bear this in mind - a meter WON'T show an instantaneous voltage drop (like when a large whack of current is pulled from the battery on a heavy bass hit), but will show the average voltage throughout the "sample time" - typically half a second or so. These high current spikes can cause an instantaneous voltage drop that a meter won't show you - you need an oscilloscope to see that.

The fact that the capacitor has cured the problem kind of indicates this to me. I'm not for a second suggesting that you should take it back, but you might be able to get even BETTER performance if the current path is tidied up. Just double-check all your connections to the battery, fuse(s), all the way to the amp. What the heck - give 'em a clean up anyway, can't hurt!

Cheerz Mate, all the best with it.

[calais_cruzin]

Cheers Phreddy, when i put the cap in I went round n redone all me cables, battery + n -, amp + n -. then i went round making sure all speaker wire was done up tight.

But wats still gets me is that the cap is meant to beep wen it charges.

Im goin to wire the Batt + into the hole at the back of cap to see if it will make the thing beep, if it dont beep looks like ive scored one with the beeper removed.

[peninsulabands]

just so you know, a good thing to do is to turn the gain on the amp for the subs and speakers right down, then turn the volume on the headunit to the max (my pioneer max vol. is 62) and then adjust the speaker and sub volume levels off that.

that way you know you will never get distortion and (hopefully) never have to worry about blowing your speakers by turning it up too loud.

[Joe Peeps]

just so you know, a good thing to do is to turn the gain on the amp for the subs and speakers right down, then turn the volume on the headunit to the max (my pioneer max vol. is 62) and then adjust the speaker and sub volume levels off that.

that way you know you will never get distortion and (hopefully) never have to worry about blowing your speakers by turning it up too loud.

Not strictly true. On certain HU's - including the pioneers from what ive been told, the RCA send a distorted signal at ~90% max volume from the HU. If this is the case, then set your gains based on the point on the volume dial just before this distortion sets in.

Edit: Also, any EQ adjustments/boosts etc made after gains are set will impact on the signal, so be wary of adding anything without adjustments to the gains or volume ceiling.

[Phreddy]

Couldn't have said it better Joey....

[Scottie_116]

i've got the same prolem with the sound getting messed up with my system. it happened when i changed my headunit over. I checked all the wiring and the earth points and they were fine. Maybe i need a cap? My h/u is an alpine 9857 i think something like that.

[Bubbaj247]

Just A tip when using Capacitors, Make sure there within at least 12inch of ya amp, as this will get the best of your cap, cheers

[calais_cruzin]

Hey all,

This problem has still been lurking around, but i have found the problem...

Its my h/u....

If i have the BBE set to effect 3 i have a major drop in bass wen turned from 22 to 23. If set on effect 2 it still drops but not as much.
Now if i turn it to effect off the thing pumps.

So what i have done is turned it to BBE effect off, then turned bass to -1 n sub up to 10.

Instead of haveing it on BBE effect 3, bass -4, sub 6

Also my h/u has been freezing, i go to use remote, it wont work, turn the knob for vol n still nothing, just sits there playin the song.

Its a pain in the ars.

So im off to go have a chat to the ppl i purchased it from n see what happens if i have to send off to get fixed.

I dont want to go without a h/u while this one is gettin fixed.
Its under 12months old.

Anyway that about it

Cheers for all the input ppl gave me.