my amp does fine at low and medium levels but once i crank it for about 5 mins the amp will shut off and come back on when i turn it down a bit, i think that i need a stronger/ better amp but my uncle says that its just the way he wired it and that he has to re-wire it.. can any one tell me what is really going on
Replies (23)
ttocs on 04/3/2007 14:40:44
what kind of amp, what kind of speakers?
swez on 04/3/2007 14:52:26
As ttocs said, what is amp make/model number and what sub(s) are used here?
This often happens when we wire up subs that are too low of ohmic load to a given amp. It'll usually work fine at moderate volumes, but when we pour on the bass, the amp will go into thermal protect mode and shut down until cool or the input signals are reduced. That's about 90% of the reason for this problem.
Swez
Bass_bass_10 on 04/3/2007 22:05:03
how do you fix that swez, is there an easy way to re-wire them or do i need to buy a new amp... i dont kno the exact make and model of the amp or subs sorry.. the amp is a 400 watt kenwood, and the subs are two 12" kenwoods..600watt max each i think
cplkittle on 04/3/2007 22:33:30
We really can't answer the question until you tell us the model numbers. It should be on the amp and on the back of the subs.
There are many variations of subs and their voice coil configurations, and to make a guess would be a shot in the dark and would not be any help for you.
swez on 04/4/2007 06:01:20
As Kittle said, w/o some additional information, it's difficult to tell you what the best options are. Amp & sub model #'s are most helpful here.
Is this amp a 2 channel version or a MONO sub amp?
Most older Kenwood subs are single voice coil models and are 4 ohms per sub. Removing one from the enclosure will tell you what's in there and a model # too.
Once we know these details, we can probably give you a solution that works.
Swez
Bass_bass_10 on 04/4/2007 16:49:05
ok i think i got enough information.. the amp is a kenwood model KAC-6202.. and the subs are 12" kenwood and the model is KFC-W300S its a 4-ohm i believe
Bass_bass_10 on 04/4/2007 17:11:55
the amp is a 2-channel by the way ^
Bass_bass_10 on 04/4/2007 18:06:02
I also want to know if adding another pair of 12" kenwoods ( same model as above) along with another kenwood amp ( also the same amp as above) will increase the loudness drastically.. or is it just a waste of money, i am trying to get the most bang for the buck
swez on 04/4/2007 18:06:09
OK, the safest way to wire these subs to this amp, is to set the amp to 2 channel mode and wire one sub per channel.
This amp is rated at 60 watts RMS x 2 in stereo mode and 100 Wrms x 2 @ 2 ohms. (200 Wrns bridged @ 4 ohms min)
Swez
Bass_bass_10 on 04/4/2007 18:16:02
so when i wire it one sub per channel.. will it still cut off at high lvls?
Bass_bass_10 on 04/4/2007 18:21:07
if so.. what about bridging it
swez on 04/4/2007 18:32:32
The amp should remain on at as it should, wired as mentioned above. If the amp gains are set too sensitively, the amp may cut off, but that is an easy adjeustment.
You cannot bridge this amp with the subs noted unless you wire both subs in series. (8 ohm load) Right now, they are probably wired in parallel for a net 2 ohm load and this makes the amp turn off when bridged. (Not 2 ohm stable when bridged)
Swez
PS A Class D amp, 300-400 Wrms will deliver for these subs though. These Kenwood subs are rated at 150 Wrms per sub and do sound pretty clean with the right enclosure and adequate power.
Bass_bass_10 on 04/4/2007 18:41:36
one last question sorry.. on the back of the amp, should it be stereo or mono(Lch).. and HPF, off, or LPF for the filter
swez on 04/4/2007 18:48:09
Stereo, LPF set to about 80 Hz.
Swez
HPRacing on 04/4/2007 21:11:37
Hi everyone! new to the site, I have a suggestion I dont recall reding from anyone in here and I think you should all think about. No matter what the amp he has and really doesn't matter what type of bass he has either. Now my only question for the person making this topic, What size and type of cable are using for the amps ground and are you if it applies to you, are you jumping moe than one amp's ground together? One Big Big known rule about amps is that no matter what size power or brand you must always have good grounds. Amps work with negative power to maintain itself working, so your best bet and I do say this with some background knowlegde you might want to check size and model of cables you are using for your grounds.
cplkittle on 04/4/2007 21:38:03
welcome, HPR.
That is a good suggestion, and yes, the amp should be grounded to a clean bare metal spot within 3' of the amplifier where applicable. The ground wire should also be the same size as the power wire. 8 gauge would be recommended in this case for both.
swez on 04/5/2007 10:19:19
Absolutely! Any amp needs adequate wiring to pass adequate current/voltage from the electrical system. Have seen some gross mis-matches done by inexperienced installers that did work out to a degree, but not over the long haul. (#12 wires, powering 500 watt amps)
In this case, the sub load is too low to bridge this amp and run the amp safely. We see this one a lot. (Most 2 channel amps are not 2 ohm stable in bridged mode and will shut off when too much heat is produced by the amp)
To be sure, there are other reasons that would cause this type of event. But the most common is miswiring the subs.
Swez
ShootuhMcBustaCap on 04/5/2007 10:22:30
I have been meaning to ask...It's not harmful to have a BIGGER ground cable than power cable right? If it si, I better go reground my stuff. I have always used a step up in the ground, and seldom use more than 6 inches of cable.
swez on 04/5/2007 10:27:09
It's not harmful to use larger grounds. It just cost more per foot to use larger gage wiring is all and sometimes harder to install a #4 wire into an amp that only accepts #8 wiring.
The length of the ground wire is a factor in choosing the proper gage wire. We often say under 3 feet as a general rule of thumb. But when using very short grounds, a smaller gage wire is often a usable option.
Swez
ShootuhMcBustaCap on 04/5/2007 10:37:02
As a rulebreaker of sorts, my "upgrade" is usually one size bigger than the amp accepts on the power side, and two sizes bigger on the ground. Putting 4 gauge into a 10 gauge amp isnt easy, but I have a way of manipulating connectors to do what I wish.
HPRacing on 04/5/2007 11:33:30
swez you are kidding right...12 gauge cables to pwer any amp...never heard of that one before. I mean i can see it happend but never tought of doing it, normally i use gauge 4 industrial no matter if its a 100 wattz amp or 1900 reason been, they delever more and normally and mostly somehting will happend, people get used to the amp and then they want to change to a bigger one.
cplkittle on 04/5/2007 20:19:32
Shootuh, I know stinger makes step down connections. I am sure there are other companies that make them too. I think they only step down from 0 to 4 to 8.
ShootuhMcBustaCap on 04/5/2007 23:28:47
Word I might have to check them out sometime. Usually, buy gold plated AudioCrimp brand connectors, and modify them by bending and cuttung with pliers, and then I solder them up real nice. Has always worked for me.
Replies (23)
ttocs on 04/3/2007 14:40:44
what kind of amp, what kind of speakers?
swez on 04/3/2007 14:52:26
As ttocs said, what is amp make/model number and what sub(s) are used here?
This often happens when we wire up subs that are too low of ohmic load to a given amp. It'll usually work fine at moderate volumes, but when we pour on the bass, the amp will go into thermal protect mode and shut down until cool or the input signals are reduced. That's about 90% of the reason for this problem.
Swez
Bass_bass_10 on 04/3/2007 22:05:03
how do you fix that swez, is there an easy way to re-wire them or do i need to buy a new amp... i dont kno the exact make and model of the amp or subs sorry.. the amp is a 400 watt kenwood, and the subs are two 12" kenwoods..600watt max each i think
cplkittle on 04/3/2007 22:33:30
We really can't answer the question until you tell us the model numbers. It should be on the amp and on the back of the subs.
There are many variations of subs and their voice coil configurations, and to make a guess would be a shot in the dark and would not be any help for you.
swez on 04/4/2007 06:01:20
As Kittle said, w/o some additional information, it's difficult to tell you what the best options are. Amp & sub model #'s are most helpful here.
Is this amp a 2 channel version or a MONO sub amp?
Most older Kenwood subs are single voice coil models and are 4 ohms per sub. Removing one from the enclosure will tell you what's in there and a model # too.
Once we know these details, we can probably give you a solution that works.
Swez
Bass_bass_10 on 04/4/2007 16:49:05
ok i think i got enough information.. the amp is a kenwood model KAC-6202.. and the subs are 12" kenwood and the model is KFC-W300S its a 4-ohm i believe
Bass_bass_10 on 04/4/2007 17:11:55
the amp is a 2-channel by the way ^
Bass_bass_10 on 04/4/2007 18:06:02
I also want to know if adding another pair of 12" kenwoods ( same model as above) along with another kenwood amp ( also the same amp as above) will increase the loudness drastically.. or is it just a waste of money, i am trying to get the most bang for the buck
swez on 04/4/2007 18:06:09
OK, the safest way to wire these subs to this amp, is to set the amp to 2 channel mode and wire one sub per channel.
This amp is rated at 60 watts RMS x 2 in stereo mode and 100 Wrms x 2 @ 2 ohms. (200 Wrns bridged @ 4 ohms min)
Swez
Bass_bass_10 on 04/4/2007 18:16:02
so when i wire it one sub per channel.. will it still cut off at high lvls?
Bass_bass_10 on 04/4/2007 18:21:07
if so.. what about bridging it
swez on 04/4/2007 18:32:32
The amp should remain on at as it should, wired as mentioned above. If the amp gains are set too sensitively, the amp may cut off, but that is an easy adjeustment.
You cannot bridge this amp with the subs noted unless you wire both subs in series. (8 ohm load) Right now, they are probably wired in parallel for a net 2 ohm load and this makes the amp turn off when bridged. (Not 2 ohm stable when bridged)
Swez
PS A Class D amp, 300-400 Wrms will deliver for these subs though. These Kenwood subs are rated at 150 Wrms per sub and do sound pretty clean with the right enclosure and adequate power.
Bass_bass_10 on 04/4/2007 18:41:36
one last question sorry.. on the back of the amp, should it be stereo or mono(Lch).. and HPF, off, or LPF for the filter
swez on 04/4/2007 18:48:09
Stereo, LPF set to about 80 Hz.
Swez
HPRacing on 04/4/2007 21:11:37
Hi everyone! new to the site, I have a suggestion I dont recall reding from anyone in here and I think you should all think about. No matter what the amp he has and really doesn't matter what type of bass he has either. Now my only question for the person making this topic, What size and type of cable are using for the amps ground and are you if it applies to you, are you jumping moe than one amp's ground together? One Big Big known rule about amps is that no matter what size power or brand you must always have good grounds. Amps work with negative power to maintain itself working, so your best bet and I do say this with some background knowlegde you might want to check size and model of cables you are using for your grounds.
cplkittle on 04/4/2007 21:38:03
welcome, HPR.
That is a good suggestion, and yes, the amp should be grounded to a clean bare metal spot within 3' of the amplifier where applicable. The ground wire should also be the same size as the power wire. 8 gauge would be recommended in this case for both.
swez on 04/5/2007 10:19:19
Absolutely! Any amp needs adequate wiring to pass adequate current/voltage from the electrical system. Have seen some gross mis-matches done by inexperienced installers that did work out to a degree, but not over the long haul. (#12 wires, powering 500 watt amps)
In this case, the sub load is too low to bridge this amp and run the amp safely. We see this one a lot. (Most 2 channel amps are not 2 ohm stable in bridged mode and will shut off when too much heat is produced by the amp)
To be sure, there are other reasons that would cause this type of event. But the most common is miswiring the subs.
Swez
ShootuhMcBustaCap on 04/5/2007 10:22:30
I have been meaning to ask...It's not harmful to have a BIGGER ground cable than power cable right? If it si, I better go reground my stuff. I have always used a step up in the ground, and seldom use more than 6 inches of cable.
swez on 04/5/2007 10:27:09
It's not harmful to use larger grounds. It just cost more per foot to use larger gage wiring is all and sometimes harder to install a #4 wire into an amp that only accepts #8 wiring.
The length of the ground wire is a factor in choosing the proper gage wire. We often say under 3 feet as a general rule of thumb. But when using very short grounds, a smaller gage wire is often a usable option.
Swez
ShootuhMcBustaCap on 04/5/2007 10:37:02
As a rulebreaker of sorts, my "upgrade" is usually one size bigger than the amp accepts on the power side, and two sizes bigger on the ground. Putting 4 gauge into a 10 gauge amp isnt easy, but I have a way of manipulating connectors to do what I wish.
HPRacing on 04/5/2007 11:33:30
swez you are kidding right...12 gauge cables to pwer any amp...never heard of that one before. I mean i can see it happend but never tought of doing it, normally i use gauge 4 industrial no matter if its a 100 wattz amp or 1900 reason been, they delever more and normally and mostly somehting will happend, people get used to the amp and then they want to change to a bigger one.
cplkittle on 04/5/2007 20:19:32
Shootuh, I know stinger makes step down connections. I am sure there are other companies that make them too. I think they only step down from 0 to 4 to 8.
ShootuhMcBustaCap on 04/5/2007 23:28:47
Word I might have to check them out sometime. Usually, buy gold plated AudioCrimp brand connectors, and modify them by bending and cuttung with pliers, and then I solder them up real nice. Has always worked for me.
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