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#132665 - 01/01/2003 22:17 negative spike bug on MK2a even after diode fix
lofreq
stranger

Registered: 04/04/2002
Posts: 49
Loc: Auckland, New Zealand
hi guys - firstly a merry xmas and happy new year to u all, i hope u had a good safe xmas season

sorry for writing so damned much but i feel the need to be descriptive so that inherent problems may become clear to you instantly whereby you could stop me immediately and point it out

ok.. after a long period of leaving things be i decided to proceed with the reinstallation of my empeg after a previous post on the same problem.

i had a problem with the empeg making a popping thru the system, when i pulled it while playing, and a different pop when starting the motor while the unit was playing. 2 different kinds of pops. i also had a problem that the player state was not being saved. at any time. or, it seemed to get saved randomly. here's a run down:

- if i pull it while playing, there is a loud hi-pitched pop or 'snap' even, quite crisp, that comes only from the left channel, and none thru the subs. never any problem with the right channel. this is the first kind of pop. player state will not be saved.

- if i start the car while it is playing, i get a low thump from the subs only, and nothing from the mids/highs speakers, then the unit cycles thru standby back to on, showing the battery icon for a few secs as expected. this is the second kind of pop.

- if, instead of just pulling it while playing, i put it into standby first (holding top button), THEN pull it, it comes out fine, no pops whatsoever. however, player state is STILL not saved! putting it back in after this 'gentle' pull sequence, and it will revert to a couple of songs ago. the loaded playlists also will differ, too.

i wasnt too worried about the pops... moreso the fact that the player state was not being saved. i tried to describe my setup and revealed that i had both IGNITION SENSE (orange) and the main power (yellow) cables going to the constant fused 12v source - as i hadnt understood how the standby timeout feature worked, and i wanted the player to run indefinitely regardless of the key being in the ACC position or not in there at all. ok, many of u responded and advised me against this wiring and said this is probably the main reason for the odd behaviour. later i posted about a connection problem where the (increasingly problematic?) left channel would fade/cut out in volume, when the car was subjected to vibration... i thought it would be a poor connection of the little pins on the connector not pressing firmly against the other pins at the back of the empeg... but someone pointed me to the 'wires falling out the back of the connector' FAQ entry and said that was probably it, so i thought ok.

so i set about to wire it correctly. after wrenching the poor sled from the dash i checked the wires on the back of the connector. all were firmly in. ok.. i then shifted the orange IGN sense wire to the switched accessories 12V output. and reinstalled everything. after alot of playing and pulling heres what ive found

the player state problem seems fixed. no matter what i do, it seems to remember the player state well and has not yet reverted to an earlier state. ok. cool!

however:

- pulling the unit while it is playing still gives me the high pitched 'pop'/'snap' from the left channel

- starting the car while the unit is playing now gives a much louder thump followed by a loud higher pitched bang (so, two seperate pops), and the unit actually completely reboots, as opposed to how it used to just go to standby then back to a playing state again
* i just realised what could be causing this second bang. my ACC line goes to 0 volts when the key is pushed to START, to crank the motor (so all power goes to the starter motor. this is probably a feature on most other cars also?). however it probably negative spikes before going to zero. so what happens is that the player thumps normally as it used to, then has a split second to make the bang due to the ACC dropping to zero, in other words it does exactly what i describe in the next paragraph:

- i now have a serious negative spike bug problem. it is exactly as described in the FAQ - when clicking from ACC to OFF, the unit remains on (playing) for about 0.5secs to 1sec, then fully shuts off with a huge almighty bang from the speakers. with a 10 speaker/2 sub 2kw installation, this thump/bang is truely frightening... testing this all out was a harrowing experience... as the faq suggests it goes completely off instead of remaining in standby.


so any time the ACC goes to zero, the player will play for about 0.5 secs to 1 sec longer, then fully shut off with a huge bang, and remain off till ACC +12V is detected again (+12v ACC will return when i turn the key from OFF back to ACC, or when i release the key from START(crank) back to ON again).

the car is an 86 honda civic - nothing exotic. i dont know if other civics also experience the negative voltage on the ACC line, instead of going to earth/gnd straight away... my unit is a mk2a and the diode is meant to be built in! so i shouldnt be hearing this at all! but i do. ok, perhaps mine was one that slipped thru without the diode fix. i went out and got a 1N4004 diode, which is 1A, 400V, the closest i could find to the recommended 1N4003. the only difference is the recommended diode handles 200V, and this is 400V. installed this and tested again - no difference!!! almighty bangs when turning off. why is this still happening??

im driving around with an empty sled now and a very helpless feeling in my gut! if youve read this far, can you suggest anything at all? are there any OTHER fixes to the negative spike problem? can i add more diodes or something? does the 200V difference in diodes make all the difference in this case? should i wire the unit differently again? theres nothing in the FAQ that tells you what to do incase the diode fix doesnt work... not that i could find anyway?

thank you VERY MUCH for reading this far and i hope you only had to go thru the first few lines before immediately spotting my problem, for the life of me i dont know what it is!

cheers all

-nige
_________________________
[P] '86 Civic Si turbo Mk2a 40Gb Smoke, 030102710

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#132666 - 02/01/2003 01:26 Re: negative spike bug on MK2a even after diode fi [Re: lofreq]
David
addict

Registered: 05/05/2000
Posts: 623
Loc: Cambridge
Could you describe how you have your amps wired up (power-wise)?

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#132667 - 02/01/2003 02:28 Re: negative spike bug on MK2a even after diode fi [Re: David]
lofreq
stranger

Registered: 04/04/2002
Posts: 49
Loc: Auckland, New Zealand
hi david..

ive tried to draw it out. i hope i havent missed out something important...



after hunting around the web i managed to stumble across a couple of posts on http://lists.merlins.org/ that had an empeg-general section. some posts from 'Ezekiel' whom i think frequents this board too? describe a similar problem here and in detailed steps here. this is back in 2000! he posts in earnest and many members try to point him in the same direction as ive been, finally in this post he describes a relay switching straight to ground method (well i think thats what it does) that worked for him...

over the weekend i will try testing the empeg by powering the unit up to play mode, then cutting the connection to the switched ACC altogether (like how he did it by pulling the fuse). ie so that its hanging in the air as an open circuit. hopefully this means no chance for any kind of spike to reach the empeg... if it doesnt bang and pop, and it goes into a nice quiet standby as expected, then id have to say its the way my car pulses the acc line, as zeke experienced. if it still bangs hard and shuts down, then i guess the empeg itself has become damaged...

if it goes into standby quietly i guess i will have to utilize zeke's relay method and provide a seperate ground to the empeg's orange IGN sense line, so that it gets a clean earth and no spiking. and pray it works!
_________________________
[P] '86 Civic Si turbo Mk2a 40Gb Smoke, 030102710

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#132668 - 02/01/2003 05:26 Re: negative spike bug on MK2a even after diode fi [Re: lofreq]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3457
Loc: Palo Alto, CA
Check the fuse in the empeg's 12v line, this sounds like it's blown. It's under a little slide-cover in the inductor block.

Hugo

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#132669 - 02/01/2003 06:54 Re: negative spike bug on MK2a even after diode fix [Re: lofreq]
Ezekiel
pooh-bah

Registered: 25/08/2000
Posts: 2413
Loc: NH USA
Well, I can't say that my memory is all too clear about what I did back in 2000, but I ditched the relays at some point and have the diode harness & no thumps. David sent me the diode harness (several, thank you!) and it was some time before I changed around the wiring. It's good now though. Sorry I can't be more helpful.

-Zeke

ps: if all else fails, the relays did work fine for me while they were in service.
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WWFSMD?

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#132670 - 02/01/2003 11:29 Re: negative spike bug on MK2a even after diode fix [Re: lofreq]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31597
Loc: Seattle, WA
Haven't read through your whole post yet, but wanted to comment thus:

when i pulled it while playing,

Popping when you pull it while playing is normal and can't be avoided.

i also had a problem that the player state was not being saved. at any time. or, it seemed to get saved randomly.

That does indicate a problem, check fuses as Hugo said.

I'll go read the rest of the posts now. Your wiring diagram looks correct, by the way.

Edit: I see the second thing was solved after you wired it correctly, but you've still got the odd bang when you go from ACC to off, which is still a problem.
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Tony Fabris

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#132671 - 02/01/2003 12:11 Re: negative spike bug on MK2a even after diode fi [Re: altman]
matthew_k
pooh-bah

Registered: 12/02/2002
Posts: 2298
Loc: Berkeley, California
Won't the empeg stop functioning if the fuse is blown? i sure seem to remember my MkIIa not working at all untill I tore the dash appart and replaced the fuse.

Anyways, I've got the same problem happening when i've got the empeg playing and then decide to start the car. It's a low frequency thump, so the majority comes from the subs, but it goes through the cabin speakers too. I'll try hauling out my backup and make sure they both do the same thing. Is there anything I can do to get rid of the thump?

Thanks,
Matthew

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#132672 - 02/01/2003 12:14 Re: negative spike bug on MK2a even after diode fi [Re: matthew_k]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31597
Loc: Seattle, WA
Won't the empeg stop functioning if the fuse is blown? i sure seem to remember my MkIIa not working at all untill I tore the dash appart and replaced the fuse.

Depends on which fuse, and which model of player. FAQ entry on this subject is here.
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Tony Fabris

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#132673 - 02/01/2003 13:17 Re: negative spike bug on MK2a even after diode fi [Re: tfabris]
matthew_k
pooh-bah

Registered: 12/02/2002
Posts: 2298
Loc: Berkeley, California
You learn something new every day. I just started rereading the FAQ the other day, but didn't get that far.

Any thoughts on the starting the engine thump?

Matthew

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#132674 - 02/01/2003 13:21 Re: negative spike bug on MK2a even after diode fi [Re: matthew_k]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31597
Loc: Seattle, WA
I think even *my* car thumps if I start the engine while it's playing.... Generally, I don't have the player playing when the engine is off, so I rarely run into that problem.
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Tony Fabris

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#132675 - 02/01/2003 13:33 Re: negative spike bug on MK2a even after diode fi [Re: lofreq]
andym
carpal tunnel

Registered: 17/01/2002
Posts: 3996
Loc: Manchester UK
In reply to:

after hunting around the web i managed to stumble across a couple of posts on http://lists.merlins.org/ that had an empeg-general section. some posts from 'Ezekiel' whom i think frequents this board too?




I believe that site and this are one and the same....
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Cheers,

Andy M

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#132676 - 02/01/2003 15:43 Re: negative spike bug on MK2a even after diode fi [Re: altman]
lofreq
stranger

Registered: 04/04/2002
Posts: 49
Loc: Auckland, New Zealand
thanks for the quick responses so far

hugo:
empeg's fuse is ok when i had the unit wired incorrectly (both yellow and orange tied together, then into the fuse, which led to the battery) it worked perfect. other than never going into standby thus draining my battery after a while.

zeke:
i meant to ask you if u ever tried the diode fix. im glad it worked for you! i dont have much more space back in there to stuff a relay in as well but looks like i'll have to try it. puzzling that my unit still bangs hard even after the diode fix. however like i mentioned, i used a 1A 400v diode instead of a 1A 200v diode, i dont know if the difference in the voltage ratings is still the problem? does anyone know? i dont think its the empeg's fault, i think its just how the ACC drops from 12v to 0, as u and many others experienced - the empeg i guess misinterprets a powerfail and bangs off?

tony:
agreed - pulling the unit while playing is probably a rare event anyway so i can understand if the pops then cant be avoided - so thats ok i can ignore that one and the engine start thump, id probably be fine with that too. at this point i just want to solve the 'hard shutdown' when going from ACC to off which isnt normal behaviour like u say... fuses are ok - what else might i check?

andy:
after reading thru more of the posts archived on the 'merlins.org' that had embedded links i noticed that they referred to empeg.comms.net, i only clicked later that the archives i was reading actually were from this board... hehe. whooops!

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[P] '86 Civic Si turbo Mk2a 40Gb Smoke, 030102710

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#132677 - 05/01/2003 13:07 Re: negative spike bug on MK2a even after diode [Re: tfabris]
schofiel
carpal tunnel

Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
Are your amps connected to a common earth and permanent 12V, switched on by the empeg REMOTE (blue) line?
_________________________
One of the few remaining Mk1 owners... #00015

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#132678 - 05/01/2003 14:34 Re: negative spike bug on MK2a even after diode [Re: schofiel]
lofreq
stranger

Registered: 04/04/2002
Posts: 49
Loc: Auckland, New Zealand
amps connected to common +12v (at the distribution block), and turned on by empeg blue wire, but are earthed seperately on two different sides of the car.
_________________________
[P] '86 Civic Si turbo Mk2a 40Gb Smoke, 030102710

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#132679 - 05/01/2003 14:50 Re: negative spike bug on MK2a even after diode [Re: schofiel]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31597
Loc: Seattle, WA
Are your amps connected to a common earth and permanent 12V, switched on by the empeg REMOTE (blue) line?

Rob, if you're asking me that question specifically (the message was a reply to my message), the answer is yes of course. The power comes straight from the battery, and the amp remote line goes straight to the empeg.

If you meant to ask lofreq, then sorry for butting in with irrelevant data.
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Tony Fabris

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#132680 - 06/01/2003 22:35 Re: negative spike bug on MK2a even after diode fi [Re: tfabris]
matthew_k
pooh-bah

Registered: 12/02/2002
Posts: 2298
Loc: Berkeley, California
In reply to:

I think even *my* car thumps if I start the engine while it's playing....




Would wiring the constant power directly to the battery fix the problem? Perhaps with a smallish capacitor inline? We've both got Hondas, so perhaps this is common with how honda's constant power in the dash works.

Do non-hondas thump when you start the engine with the player playing?

Matthew

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#132681 - 06/01/2003 23:53 Re: negative spike bug on MK2a even after diode fi [Re: matthew_k]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31597
Loc: Seattle, WA
Would wiring the constant power directly to the battery fix the problem?

Mine is already this way.

Perhaps with a smallish capacitor inline?

Once I had a capacitor network inline for my Mk1 (and it's not as simple as just wiring one capacitor, you also need a diode and the correct wiring and grounding), and this prevented some of the problems on the Mk1. But a properly-wired Mk2 shouldn't need a capactor. Heck, the Mk1 shouldn't have needed it either, but I deliberately wired the Mk1 incorrectly for my own reasons.

We've both got Hondas, so perhaps this is common with how honda's constant power in the dash works.

It's got nothing to do with the dash wiring. It's that Hondas have high-RPM starter motors that really draw a whole lot of juice from the whole car's electrical system.
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Tony Fabris

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