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Hey guys I have a problem. I installed a Fosgate P300-1 amp and a Fosgate P2D412 sub into my sons 2008 Honda Civic. It was in his previous 2007 civic with no problems. It worked fantastic however in the new car that is a different story. Here is the problem.
His new car does not have preamp outputs so we used an inline converter. I grabbed the signal from his rear speakers both left and right. I then put the RCA cables to the AMP. It sounds great but here is where the problem comes in.
When he turns the music off the subwoofer continues to put out enormous amounts of low frequency. If I turn down the gains on the line level to stop it, the sub is so low it hardly makes a difference.
Are the competing signals from the left and right channel competing against each other and therefore causing the speaker to oscilate? If so will removing one line input solve the issue? I could just use a y cable to tie into the amp and only use one side of the line converter.
What say you?
Thanks, Jeff
Posts: 10 | From: Ohio | Registered: Jun 2008
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the gain knobs(looks for 2 3/16 that you put a small flat screwdriver in to adjust) turn down. if there isnt any on the one you bought turn the gain down on the amp til it stops.
if you still have a problem use the ground on the converter.
last ur converter might not be strong enough for the radio's output. what kind is it?
Posts: 6348 | From: north rose,ny | Registered: Aug 2002
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I have the line converter turned down to around a quarter. Any more than that and the sub goes crazy. If I turn it up, the sub hits like it did in the old Civic but like I said, when I turn off the radio, it continues with what I would say is 30 Hz frequency. The sub is just throwing.
I tried grounding the converter to the same location as the amp but it did not work. Does it need to go clear back to the head unit? I really do not want to tear the dash apart.
As far as the radio, it is a stock Honda unit. It has the premium stereo rated at 350 watts. I imagine that is peak but it does have a dedicated 8" free air sub.
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Also another forum suggested tying the converter into the factory sub instead of the lh and rh 6 1/2". Their suggestion was Connect both LH and RH positive leads to the factory sub's + and both line level negatives to the subs - side. Is this going to work which would give me access from the radio to control both subs simotaniously?
The scenario is 61/2" LH an 8" free air and a 6 1/2" RH all on the back panel. Currently I am tied into the 6 1/2" on either side.
Posts: 10 | From: Ohio | Registered: Jun 2008
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are you sure you have a good amp ground? let's see a picture of that. does the new car have the noise canceller like the '09 accords?
-------------------- World Record-Loudest SPL in my driveway Team Powermaster/XS-Power Hifonics Amps, Kicker subs-The way it should be....all were Stolen from me...boo hoo Zensky....World Domination at It's Finest www.zensky.com Posts: 3723 | From: Columbus, OH - formerly FL | Registered: Oct 2003
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does the thumping stop if you open the trunk or doors? Some of those newest honda's have an active noise cancellation circuit. You need to NOT get your signal for the line-output converter in the trunk. That's step one. get it behind the dash on low-level. If that doesn't make it go away while doors and windows shut, try unplugging the vehicles interior microphone. Do you have factory navigation?
-------------------- World Record-Loudest SPL in my driveway Team Powermaster/XS-Power Hifonics Amps, Kicker subs-The way it should be....all were Stolen from me...boo hoo Zensky....World Domination at It's Finest www.zensky.com Posts: 3723 | From: Columbus, OH - formerly FL | Registered: Oct 2003
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and get used to doing it this way, guys. This will be a common problem at smaller shops where your installers are less knowledgeable or less experienced with new technologies. Shops that do lots of wholesale work for dealers will obviously run into it first and figure it out.
-------------------- World Record-Loudest SPL in my driveway Team Powermaster/XS-Power Hifonics Amps, Kicker subs-The way it should be....all were Stolen from me...boo hoo Zensky....World Domination at It's Finest www.zensky.com Posts: 3723 | From: Columbus, OH - formerly FL | Registered: Oct 2003
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No it does not stop. Until I turn down the gains on the line level it continues even after the music stops. I tried every imaginable was of stopping it.
It does not have the navigation, just the "premium" 7 speaker system. I am not sure of the active noise cancellation but I searched Honda's website and it appears to only be offered on the Accord, Odyssey, and Pilot.
As far as the line signal was really hoping to NOT get the signal from the dash. To dig into it looks a bit cumbersome. Do you think because it is an amplified signal that this may be the culprit? That was my initial guess but someone over at Crutchfield forums did not think this is the issue. Also, do you know of a source where I could get the dash/radio removal information on the 08 Civic?
I will get a picture but the amp ground is coming from the rear trunk latch. It has been sanded to bare metal. This was the best place givin my ground cable limitations. I had used this many moons ago in my own installs. Back in the Richard Clark days. (well test your age here)
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After discussing with one of my installers, VRix "Your rear speakers are acting as microphones, and being amplified by the LOC and amp when the music goes away. One fix is putting some distance (resistance) between the LOC and the speker, ie. putting it behind the radio. Infinity gives you 4 resistors to use with their Bass-link if this happens. I forget details, but I think they tell you to just put them in-line with the +s? It's perfectly fine to grab a mono signal at the factory subwoofer for your converter. Would recommend disconnecting said woofer and rockin' just the Fosgate.
Also, if you're tied into ignition for remote turn on I'd recommend some sort of signal-sensing turn on doohickey. I bet this sound is more likely to happen when you turn your radio off vs. just turning it all the way down, right?"
-------------------- World Record-Loudest SPL in my driveway Team Powermaster/XS-Power Hifonics Amps, Kicker subs-The way it should be....all were Stolen from me...boo hoo Zensky....World Domination at It's Finest www.zensky.com Posts: 3723 | From: Columbus, OH - formerly FL | Registered: Oct 2003
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so essentially the rear speakers are sending reverse voltage into the inputs...just like how a microphone works.
-------------------- World Record-Loudest SPL in my driveway Team Powermaster/XS-Power Hifonics Amps, Kicker subs-The way it should be....all were Stolen from me...boo hoo Zensky....World Domination at It's Finest www.zensky.com Posts: 3723 | From: Columbus, OH - formerly FL | Registered: Oct 2003
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i know what ur talking about dbass because i have seen it happen. normally lowering the gain takes care of it.
what is the gain and bass boost set at? turn ur bass boost off. then turn ur amps gain to 1/4 next turn on ur gains up on the loc slowly til it starts to bass with the headunit off then back them down just a little.
i have used ALOT of loc's over the yrs in customers installs.
i will sell ya a loc with remote turn on for cost + shipping if you want pm me. i keep alot of them instock. if you want just the remote turn on module from metra i have those too, though not as good as the 1 piece...
Posts: 6348 | From: north rose,ny | Registered: Aug 2002
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you are talking about signal-sensing turn-on, correct? because that is what he needs with this.
-------------------- World Record-Loudest SPL in my driveway Team Powermaster/XS-Power Hifonics Amps, Kicker subs-The way it should be....all were Stolen from me...boo hoo Zensky....World Domination at It's Finest www.zensky.com Posts: 3723 | From: Columbus, OH - formerly FL | Registered: Oct 2003
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Sorry, I did not get a picture tonight. I forgot I had to go to my daughters dance recital. 3 plus hours of that stuff. Wears you out but it is cool to see such a big production for the girls.
The problem is when we turn it off. What you have said makes sense in regards to it acting like a microphone.
I am able to effectively eliminate the issue by turning the gains down but then there is no need for the sub since the levels are so low. I tried every possible setting from amp gains, crossover points, LOC gains, etc. Only when turned low enough does it go away. So I guess I will try to put the LOC behing the radio and grab the sub channel. Can I just hook one side of the LOC to the radio or should I use both sides as stated above in my previous post regarding combining the LH and RH positive and LH and RH negatives on the LOC.
Still better yet what type of resistors can I get? Is this something radio shack might have or do I need to order them. I really do not want to go into the dash unless absolutely needed.
If this does not work I will take you up on the LOC with remote turn on. I will have to tell my son to cough up the coin. What is the cost? I will let him know if this does not work.
Posts: 10 | From: Ohio | Registered: Jun 2008
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Also, if you're tied into ignition for remote turn on I'd recommend some sort of signal-sensing turn on doohickey. I bet this sound is more likely to happen when you turn your radio off vs. just turning it all the way down, right?"
I grabbed my remote from the fuse box via an unused fuse. This should not cause the problem should it? It is just turning the amp on.
Posts: 10 | From: Ohio | Registered: Jun 2008
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it could be. you ONLY want the remote turn-on to have power while the radio is on. that way if the car is on, but the radio is not....the amp will turn off. when the radio is on, even with volume at zero, there is still voltage present on the speaker leads. when the radio is turned off is the only time the speaker leads have zero voltage. If remote lead is on ignition, the amp will stay on even with the radio off. then any vibration that moves the speaker even the slightest creates a voltage in the speaker line. the LOC picks that up, and amplifies it. causing more sound, which creates more vibration, which creates more amplification, and the loop continues. By using a signal-sensing remote turn-on, the amplification only happens when the radio is on, which is when there is a base voltage on the speaker/signal leads. So with 0.2volts as your "voltage floor", a 0.01voltage created by vibration is less powerful, and therefore won't create such a loop. By picking up that signal all the way 15feet from the speaker(behind the radio), you have extra resistance in the line that could reduce that 0.01volts to 0.001volts, reducing it even greater.... sort of like that. numbers were made up though.
-------------------- World Record-Loudest SPL in my driveway Team Powermaster/XS-Power Hifonics Amps, Kicker subs-The way it should be....all were Stolen from me...boo hoo Zensky....World Domination at It's Finest www.zensky.com Posts: 3723 | From: Columbus, OH - formerly FL | Registered: Oct 2003
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yes dbass that is what i am taking about it makes a remote lead from stock speaker wires.
i only ever use right rear when hooking up a loc, just twist both + together and do the same with the -'s.
putting out the offer mods dont delete because there is no profit made, tring to help a guy out.
audiopipe loc with remote wire sensing $20 metra just the sencing $15 these are prices shipped. let me know and i will ship one out asap for ya.
all you have to do is pm me ur addy and when you recieve the package send me a check or money order. cant get any easier than this...
Posts: 6348 | From: north rose,ny | Registered: Aug 2002
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when I first read this - my first thought was installing a sub with the "oscillating fan" concept. Where the sub would rotate side to side back and forth. Which is an interesting concept in and of itself to disperse the bass. I dont think it would work well - but it made me go "hmmmmmmm" and visualize it in my head.
Then I read it and realized - oh - they arent talking anything at all about that. Ok.
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Well everything worked like a charm. Thing sounds much better. My son has a big grin on his face. He already ordered some new alpines for the doors.
MUCH THANKS TO ALL WHO CONTRIBUTED. It is greatly appreciated.
Posts: 10 | From: Ohio | Registered: Jun 2008
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no problem. the spl world is for the most part a tight-nit community
-------------------- World Record-Loudest SPL in my driveway Team Powermaster/XS-Power Hifonics Amps, Kicker subs-The way it should be....all were Stolen from me...boo hoo Zensky....World Domination at It's Finest www.zensky.com Posts: 3723 | From: Columbus, OH - formerly FL | Registered: Oct 2003
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