Question concerning amp clipping??
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Le Mans Master
Joined: Dec 2002
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From: Piedmont, SC Currently Own: 99 Nassau blue FRC. Previously Owned: 84,95,98 Indy Pace,01 Z06
Question concerning amp clipping??
Well, after I seemed to have the stereo sounding the way I like it, I have been having a problem with my mono amp clipping. I am running a Hifonics BX1500D amp to a Farenheit CK12D sub. The sub is dual 4ohms and is wired to produce a 2ohm load to the amp. The bass boost is at 0 along with the HU @ 3 for the bass. The HU can go up tp 15, but at 3 there is enough bass that I like it there. I usually keep it around 0-3 for the bass on the HU. The gain is set @ around 4.5-5v and it usually clips when I am listening to some heavy bass notes at around volume 28 or 29 on my Kenwood KDC-MP828 deck. The amp will stay off or I will not hear any bass until I restart the car. What could be the cause of this? The sub is set around 80 hz and everything else on the amp is set to 0 or the lowest it can go.
-Jason
-Jason
Thread Starter
Le Mans Master
Joined: Dec 2002
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From: Piedmont, SC Currently Own: 99 Nassau blue FRC. Previously Owned: 84,95,98 Indy Pace,01 Z06
BTW, I do have 4 gauge power and ground wires! I'm wondering if the amp may be getting too hot since it is mounted in the back on a partition.
Team Owner
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Ok, that amp is good to a 1-Ohm load and yours is only seeing 2-Ohm mono the way you have it wired. I agree with the above post. Check to make sure you have a tight, solid ground point.
Thread Starter
Le Mans Master
Joined: Dec 2002
Posts: 7,981
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From: Piedmont, SC Currently Own: 99 Nassau blue FRC. Previously Owned: 84,95,98 Indy Pace,01 Z06
I'll check that here in a litlle bit. My Hifonics ZX4400 4 channel amp has been working just fine, but then again I know for a fact that it is grounded to the seat bolt.
Thread Starter
Le Mans Master
Joined: Dec 2002
Posts: 7,981
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From: Piedmont, SC Currently Own: 99 Nassau blue FRC. Previously Owned: 84,95,98 Indy Pace,01 Z06
Well, the ground issue may have been the problem. I had it grounded to one of the bolts/screws that is around the center compartment area. I did this because that was where the audio installer grounded my other amp when I had my '98 Pace Car. I guess I will just run another ground to the other seat bolt and call it good. I wondered why my other amp in my Pace Car would sometimes clip also. I'll get some ground wire and post back my results.
-Jason
-Jason
Intermediate
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Originally Posted by NVTHIS
Well, after I seemed to have the stereo sounding the way I like it, I have been having a problem with my mono amp clipping. I am running a Hifonics BX1500D amp to a Farenheit CK12D sub. The sub is dual 4ohms and is wired to produce a 2ohm load to the amp. The bass boost is at 0 along with the HU @ 3 for the bass. The HU can go up tp 15, but at 3 there is enough bass that I like it there. I usually keep it around 0-3 for the bass on the HU. The gain is set @ around 4.5-5v and it usually clips when I am listening to some heavy bass notes at around volume 28 or 29 on my Kenwood KDC-MP828 deck. The amp will stay off or I will not hear any bass until I restart the car. What could be the cause of this? The sub is set around 80 hz and everything else on the amp is set to 0 or the lowest it can go.
-Jason
-Jason
Use Ohm's Law to determine the proper output voltage you should be reading from the amps. These manufacturers use 14.4V input voltage to get their power ratings
so you'll need to knock off 30% from their ratings to get true in-car output.For this amp, the formula should look like this: SqRt(787.5 x 2 ) = 39.6V AC. Turn the "gain" until you read this number on the screen.
When taking a voltage reading from the amp outputs, the speaker needs to be disconnected, the volume set to roughly 3/4 and all equalization set to flat. It's important that the tone you use is within the x-over range (50 Hz should be good).
There is a Flash movie that explains the process here: http://mobile.jlaudio.com/support_pages.php?page_id=143
Le Mans Master
Joined: Nov 2004
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From: Dyer IN
Cruise-In IX Veteran
It could also be a poor ground though we see it at work alot, when the amp goes to pull over X amount of voltage the ground just cant support it anymore and the amp shuts down
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Melting Slicks
Joined: Dec 2004
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From: Bay Area CA
Good explanation on the ground issue penta you da man
As for the clipping thing NV I think you have a pretty good handle on the tuning and gain setting at this point. Usually amps that are being sent into extreme clipping will shut down and not power back on when the car is restated due to them overheating (generally).
Hope you get it dialed in bro
Fej
Thread Starter
Le Mans Master
Joined: Dec 2002
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From: Piedmont, SC Currently Own: 99 Nassau blue FRC. Previously Owned: 84,95,98 Indy Pace,01 Z06
Well Folks it doesn't appear to be a ground issue because it still does it and i grounded it to the passenger seat frame bolt. Once the amp shuts off, there is no protection light on or even before it does this. The sub sounds funny though! It sounds good sitting up in the front, but once you go back and pop the trunk the sub is making a loud popping noise and I'm thinking that maybe the voice coil or something has came apart and it's slapping something. I got this particular sub used, so maybe it's bad. I have another one so I may try that one and see if it does the same thing. To be honest the sub sounds fine up front and at back while around volume 20 on the HU. There maybe slight popping under heavy bass songs on the HU, but once I crank it up to around 28 the sub starts popping something fierce and sounds like it is going to blow up,lol. Again, you cannot hear this while sitting in the car, but you can hear it very easily when you go back and look at the sub. Any other suggestions??
Melting Slicks
Joined: Dec 2004
Posts: 2,394
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From: Bay Area CA
Well, you could start with a reset of the amps gains BY EAR with a track you know well, or one that you know has been causing the popping sound, or you could download some sine waves of say 30-60hz at 5 hz intervals and check to see how the sub performs. Also you could push the sub for about 5 minutes and then smell the sub for a burning smell, voice coils could be on their way. I guess I have it narrowed down now, it could be your amp dying, your sub dying, or your gains are too high and clipping 
Fej
Fej
Thread Starter
Le Mans Master
Joined: Dec 2002
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From: Piedmont, SC Currently Own: 99 Nassau blue FRC. Previously Owned: 84,95,98 Indy Pace,01 Z06
I will double check the gains again, but I'm confused,lol! I had two of the Farenheit CK10's in my truck with an 1100 watt amp pushing them and they were extremely LOUD! At Vol 28 on the HU with the gains set around 4.5-5V or 12'oclock position, the bass is loud, but not nowhere near as loud as what was in my truck. It sounds like someone is tapping the cone with their fingernail really Loud. Could it be tinsel slap? If so why is the amp clipping or why is it shutting off? Maybe bad amp? I don't know,lol. I will check some things tomorrow and try another sub. This amp should really pound this 12, but I don't know which one is faulty at the moment. I don't think it is a gain issue as most everything else is et very low. I appreciate all you guys inputs and hopefully we will get to the bottom of this!
-Jason
-Jason
Thread Starter
Le Mans Master
Joined: Dec 2002
Posts: 7,981
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From: Piedmont, SC Currently Own: 99 Nassau blue FRC. Previously Owned: 84,95,98 Indy Pace,01 Z06
Well, I got a chance to build me another box today to house a new sub, so I tried this particular one, but this time I wired the sub a little differently. It is a Diamond Audio D310D4 and so I wired it with each voice coil going to a channel since I am running a big amp with a smaller sub. Well the good news is that I don't hear any popping and the sub sounds good with basically the same gain settings as I used on the Farenheit. I have had alot of good luck with the Old School Farenheits such as the CK12d's and the CK10d's, so I have never had this problem. I guess since I purchased this one used that it could have been abused by the previous owner. I assume something was coming apart in the CK12, but that's ok I do have another one to replace it with and I will see if that one sounds the same. I haven't had time to really play this diamond audio sub, but will test it out tomorrow and hear the full effects.
