I hope someone can help with this problem I am having.. when I turn my deck up loud the subs will cut out.. they don't always cut out too, it's strange.. once in a while it will do this and I'll have to listen to the music real low for a couple days and then it goes back to normal.. because of this I think it's a power issue.. either the battery isn't making power fast enough or maybe the amp for the subs isn't big enough, but I'm not too sure.. can anyone suggest anything? Here is my set up below:
Optima Yellow Top Battery
4 gauge wires to a Rockford Fosgate 1 farad cap
One 4 gauge wire out to JL Audio 500/1 amp running 2 10" Boston Acoustics Pro Series Woofers
One 4 gauge wire out to Alpine MRV-F307 amp running 1 set of Boston Acoustics 5.5 Pro Series Components in the front doors and 1 set of Boston Acoustics 6.5 Pro Series Components in the rear deck
Replies (8)
uochronos on 05/26/2004 02:13:50
if this is a power issue it is your alternator that is not making enough power at this point. and that well need to be upgraded.
do your lights dim? does your car idle rough when bass has been hitting for a long time? are there any other straneg stuff happening?
compvr15s on 05/26/2004 09:30:36
try re-grounding your amps. how do you have them grounded now? make sure they are strait to bare metal. do not ground through your cap. i would recommend tryin to get a better ground before you go lookin in other areas. i havnt heard of an alternator that works sometimes and not others, you say you have to wait a few days i dont see why that would happen. if you have a loss of power your pretty much screwed. an alternator doesnt recharge your battery it just keeps it a constant level. also upgrade your ground from your battery to your body frame and the wire from your battery to your alternator. use 4awg wire for this, allows for optimum power flow. if that dont work then come back and maybe we can steer you in a different direction. good luck
swez on 05/26/2004 09:44:25
Nice product grouping here Mr. Whitehead!
Chronos might be on to part of the issue... depends on how much current your ALT can put out, your gain settings and how much of an ohmic load the amp is seeing.
1. This is a smaller vehicle. Do you know the present ALT output current available from this ALT? That CAP may be part of the equation here as well. If it has a voltage reading circuit on it, have a look and see that it is above 12.5 volts. If not, the sub amp may cut out for lack of enough power. Say more on this subject please.
2. If only the sub amp is dropping out, your input gain setting may need to be change. This amp has a dual range input voltage selector. It needs to be set optimally to provide best performance w/o cutting of the amp. What is the present gain setting. Which selector is used now? (Low or high RCA voltage input range) Knowing what your HU can put out in RCA voltage will determine the input range and settings for gain. What HU are you using now and what is the gain setting/range on your JL amp?
3. The subs noted, which model number are you using here and how are the subs wired for this amp? This amp will deliver same power (500 RMS) between 1.5 - 4.0 ohms. If your subs are lower than 1.5 ohms as wired, this will also cause the sub amp to shut down. Say more here too please.
Since this only seems to affect your subs, we can isolate the possible issues to power supplied to sub amp. The CAP & amp have to have a solid ground & power connection. The other variables are the input sensitivity settings used, bass boost amount (should not need more than a few dB of boost) and sub ohmic load to amp. Other than that, can this present ALT maintain enough current to supply all demands from normal car operation and amps noted?
Comments?
Swez
compvr15s on 05/26/2004 09:52:25
why wouldnt jl make their amps 1ohm to 4omh stable, it would make things alot easier wouldnt it. or will that handle 1 ohm? i know some subs will say 4 ohms but actually may be a lil higher or lower. i been wondering this for a long time just finally remembered it at the right time.
swez on 05/26/2004 10:05:04
All speakers have a nominal resistance value. This resistance value changes dramatically with frequency. When subs are close to Fs, the impedance value is very high. As the speaker gets signals above Fs, (resonance freq.) the ohmic value drops rapidly. This is a phenomena caused by "inductive reactance." All speakers have this issue to a degree.
When we measure a voice coil with an ohmeter, it will give a DC resistance number. (Re) That number is lower than its nominal rated AC resistance. If you read a coil with an ohmeter, them move the cone in and out, the DC resistance will change. You can see this on the meter as well.
Swez
MrWhithead on 05/26/2004 11:50:32
This is a great message board, thanks for all your help guys!brbrOkay, I don't really understand what all the settings do on the amp and how they effect each other... I had a shop do the install but I really want to know more about the equipment so I can fix problems like this on my own.. here are the settings on my amp, and one correction.. the amp is a JL 250/1 not 500/1.. brbrIt is on Low-Pass setting, Freq 65, LF Boost +1, High Input voltage, signal sensing onbrbrThe subs are Pro Series 10.5LF and they're 2 Ohm..brbrThe amps are grounded through the cap and the cap is grounded to the floor board in the trunk.. the cap doesn't have a voltage reading circuit on it so I'm not sure about that.. brbrAlso I believe the alternator power is 105 amps for '97 sunfires.brbrAnd the head unit I have now is a Clarion DRX 9575rz which I'll be replacing with an Alpine CDA-9835 soon since the LCD display in the Clarion went and to fix it I'd have to replace the circuit board which will cost about $300. I decided I'm just going to get a new one with mp3 and no LCD..brbrAlso about a year ago I added the cap to the equation because I was having problems with my headlights and dash lights dimming.. this seems to have solved that problem but there could be an underlying problem here that I don't realize.
compvr15s on 05/26/2004 14:25:53
that cap is pretty much there for the "bling" its power storage is so small is pretty much useless. but since you have its thats not a big problem. first thing i would do if i was you then is to upgrade the power wires under the hood, 4awg from alt to battery and from battery to body of car. i know when i had my amps grounded through my cap my subs used to cut out and be really choppy due to excesive ground length. did you make sure to check and see if they filed/sanded the paint under the ground wire. once you have done this, try removing the cap completly to see if your lights still dim... the biger wire under the hood should help you in this situation.... if you have a problem with your subs cuttin out for a couple of days then theres something else... your subs are two ohm? each or 2 ohm load runnin to your amp? if you run the amp past its allowable ohm usage the amps throughs itself into a protect mode to ensure that you dont damage the equipment.... do you know if your amp is shutting off when the subs go out, if you have it happen again, goto the trunk and feel the amp, if its extremely warm then its probably is being pushed beyond its capabilities. you may very well have a bad alternator but i know my grand prix has the same amps reading as yours and it pushes two amps that run about 110 -120 amps together at full usage without a problem. can have it tested at local parts store for free.... good luck.... swez please comment. ole mighty bright one SMILE
i kind of feel like daniel son and swez is mr. meogee from the karate kid, have learned so much from you...
swez on 05/26/2004 19:27:48
OK... where to start?
Subs: These are 2 ohm SVC (single coil). For the amp you have now, they need to be wired in series for a net ohmic load of 4 ohms. If they are wired in parallel, you have a net 1 ohm load. This would be very hard on your amp at high SPL levels and may cause it to shut down or go protect mode on you. Inspect the sub wiring or ohmic value with an ohmeter to confirm the wiring used. (series is good, parallel is bad)
You mentioned the amp input sensitivity selector is on high. This HU notes a 4 volt output at RCA's. Your amp sensitivity selector should be set to ~3.0 volts. If setting is less than 2.0 volts, re-adjust to 3.0 volts and see how that works out.
Was looking at that HU and its features. Wow, that thing can do everything but pour your coffee, fetch the paper and take out the trash. GRIN Am wondering that since the display is going south, you may have other circuits in there that are also acting up. (Sub out features in particular???) I say that only because of your comments that the subs shut down for long periods of time, then come back on. If only an amp overheating issue, the subs will come back in after a few minutes... then shut off if amp gets too hot again. (cycling on/off)
Hopefully, the new HU mentioned (Alpine ) will be less hassles for you. FYI... I believe Alpine makes a few HU's w/o power amps in the unit. This model (CDA-9835) has the V-Drive high power Mosfet amp circuits in it. Since you already have dual outboard amps, don't need a HU w/ internal amps... just RCA outs for F,R & sub. Should be cheaper too. Why pay for something you do not need?
Have a look at this model for comparison:
http://www.crutchfield.com/S-FnNVNeou3ce/cgi-bin/ProdView
.asp?s=0&c=3&g=62700&I=500CDA7998&o=p&a=0&cc=01
&avf=N&search=alpine
Alpine CDA-7998 is ~ #150.00 cheaper than CDA-9835
Finally, it is best when using a CAP and 2 amps, to only use trhe Cap on the sub amp. The 4 channel amp does not need a CAP and all amps and CAP should be grounded to the same location to minimize noise. Try resetting your sub amp gain as noted earlier and see if this improves performance. Also, check your sub wiring to amp as well. If these subs are both wired to amp in parallel, this will cause the sub amp to shut down at high volume levels.
Let us know what you find out OK?
Swez
PS CompVR... you are to funny my "Little Grasshopper" ! But you have learned a lot in past 6 months and I am proud to have you as a student. Keep up the good work... and fix that darn stick keyboard problem soon huh? SMILE
Optima Yellow Top Battery
4 gauge wires to a Rockford Fosgate 1 farad cap
One 4 gauge wire out to JL Audio 500/1 amp running 2 10" Boston Acoustics Pro Series Woofers
One 4 gauge wire out to Alpine MRV-F307 amp running 1 set of Boston Acoustics 5.5 Pro Series Components in the front doors and 1 set of Boston Acoustics 6.5 Pro Series Components in the rear deck
Replies (8)
uochronos on 05/26/2004 02:13:50
if this is a power issue it is your alternator that is not making enough power at this point. and that well need to be upgraded.
do your lights dim? does your car idle rough when bass has been hitting for a long time? are there any other straneg stuff happening?
compvr15s on 05/26/2004 09:30:36
try re-grounding your amps. how do you have them grounded now? make sure they are strait to bare metal. do not ground through your cap. i would recommend tryin to get a better ground before you go lookin in other areas. i havnt heard of an alternator that works sometimes and not others, you say you have to wait a few days i dont see why that would happen. if you have a loss of power your pretty much screwed. an alternator doesnt recharge your battery it just keeps it a constant level. also upgrade your ground from your battery to your body frame and the wire from your battery to your alternator. use 4awg wire for this, allows for optimum power flow. if that dont work then come back and maybe we can steer you in a different direction. good luck
swez on 05/26/2004 09:44:25
Nice product grouping here Mr. Whitehead!
Chronos might be on to part of the issue... depends on how much current your ALT can put out, your gain settings and how much of an ohmic load the amp is seeing.
1. This is a smaller vehicle. Do you know the present ALT output current available from this ALT? That CAP may be part of the equation here as well. If it has a voltage reading circuit on it, have a look and see that it is above 12.5 volts. If not, the sub amp may cut out for lack of enough power. Say more on this subject please.
2. If only the sub amp is dropping out, your input gain setting may need to be change. This amp has a dual range input voltage selector. It needs to be set optimally to provide best performance w/o cutting of the amp. What is the present gain setting. Which selector is used now? (Low or high RCA voltage input range) Knowing what your HU can put out in RCA voltage will determine the input range and settings for gain. What HU are you using now and what is the gain setting/range on your JL amp?
3. The subs noted, which model number are you using here and how are the subs wired for this amp? This amp will deliver same power (500 RMS) between 1.5 - 4.0 ohms. If your subs are lower than 1.5 ohms as wired, this will also cause the sub amp to shut down. Say more here too please.
Since this only seems to affect your subs, we can isolate the possible issues to power supplied to sub amp. The CAP & amp have to have a solid ground & power connection. The other variables are the input sensitivity settings used, bass boost amount (should not need more than a few dB of boost) and sub ohmic load to amp. Other than that, can this present ALT maintain enough current to supply all demands from normal car operation and amps noted?
Comments?
Swez
compvr15s on 05/26/2004 09:52:25
why wouldnt jl make their amps 1ohm to 4omh stable, it would make things alot easier wouldnt it. or will that handle 1 ohm? i know some subs will say 4 ohms but actually may be a lil higher or lower. i been wondering this for a long time just finally remembered it at the right time.
swez on 05/26/2004 10:05:04
All speakers have a nominal resistance value. This resistance value changes dramatically with frequency. When subs are close to Fs, the impedance value is very high. As the speaker gets signals above Fs, (resonance freq.) the ohmic value drops rapidly. This is a phenomena caused by "inductive reactance." All speakers have this issue to a degree.
When we measure a voice coil with an ohmeter, it will give a DC resistance number. (Re) That number is lower than its nominal rated AC resistance. If you read a coil with an ohmeter, them move the cone in and out, the DC resistance will change. You can see this on the meter as well.
Swez
MrWhithead on 05/26/2004 11:50:32
This is a great message board, thanks for all your help guys!brbrOkay, I don't really understand what all the settings do on the amp and how they effect each other... I had a shop do the install but I really want to know more about the equipment so I can fix problems like this on my own.. here are the settings on my amp, and one correction.. the amp is a JL 250/1 not 500/1.. brbrIt is on Low-Pass setting, Freq 65, LF Boost +1, High Input voltage, signal sensing onbrbrThe subs are Pro Series 10.5LF and they're 2 Ohm..brbrThe amps are grounded through the cap and the cap is grounded to the floor board in the trunk.. the cap doesn't have a voltage reading circuit on it so I'm not sure about that.. brbrAlso I believe the alternator power is 105 amps for '97 sunfires.brbrAnd the head unit I have now is a Clarion DRX 9575rz which I'll be replacing with an Alpine CDA-9835 soon since the LCD display in the Clarion went and to fix it I'd have to replace the circuit board which will cost about $300. I decided I'm just going to get a new one with mp3 and no LCD..brbrAlso about a year ago I added the cap to the equation because I was having problems with my headlights and dash lights dimming.. this seems to have solved that problem but there could be an underlying problem here that I don't realize.
compvr15s on 05/26/2004 14:25:53
that cap is pretty much there for the "bling" its power storage is so small is pretty much useless. but since you have its thats not a big problem. first thing i would do if i was you then is to upgrade the power wires under the hood, 4awg from alt to battery and from battery to body of car. i know when i had my amps grounded through my cap my subs used to cut out and be really choppy due to excesive ground length. did you make sure to check and see if they filed/sanded the paint under the ground wire. once you have done this, try removing the cap completly to see if your lights still dim... the biger wire under the hood should help you in this situation.... if you have a problem with your subs cuttin out for a couple of days then theres something else... your subs are two ohm? each or 2 ohm load runnin to your amp? if you run the amp past its allowable ohm usage the amps throughs itself into a protect mode to ensure that you dont damage the equipment.... do you know if your amp is shutting off when the subs go out, if you have it happen again, goto the trunk and feel the amp, if its extremely warm then its probably is being pushed beyond its capabilities. you may very well have a bad alternator but i know my grand prix has the same amps reading as yours and it pushes two amps that run about 110 -120 amps together at full usage without a problem. can have it tested at local parts store for free.... good luck.... swez please comment. ole mighty bright one SMILE
i kind of feel like daniel son and swez is mr. meogee from the karate kid, have learned so much from you...
swez on 05/26/2004 19:27:48
OK... where to start?
Subs: These are 2 ohm SVC (single coil). For the amp you have now, they need to be wired in series for a net ohmic load of 4 ohms. If they are wired in parallel, you have a net 1 ohm load. This would be very hard on your amp at high SPL levels and may cause it to shut down or go protect mode on you. Inspect the sub wiring or ohmic value with an ohmeter to confirm the wiring used. (series is good, parallel is bad)
You mentioned the amp input sensitivity selector is on high. This HU notes a 4 volt output at RCA's. Your amp sensitivity selector should be set to ~3.0 volts. If setting is less than 2.0 volts, re-adjust to 3.0 volts and see how that works out.
Was looking at that HU and its features. Wow, that thing can do everything but pour your coffee, fetch the paper and take out the trash. GRIN Am wondering that since the display is going south, you may have other circuits in there that are also acting up. (Sub out features in particular???) I say that only because of your comments that the subs shut down for long periods of time, then come back on. If only an amp overheating issue, the subs will come back in after a few minutes... then shut off if amp gets too hot again. (cycling on/off)
Hopefully, the new HU mentioned (Alpine ) will be less hassles for you. FYI... I believe Alpine makes a few HU's w/o power amps in the unit. This model (CDA-9835) has the V-Drive high power Mosfet amp circuits in it. Since you already have dual outboard amps, don't need a HU w/ internal amps... just RCA outs for F,R & sub. Should be cheaper too. Why pay for something you do not need?
Have a look at this model for comparison:
http://www.crutchfield.com/S-FnNVNeou3ce/cgi-bin/ProdView
.asp?s=0&c=3&g=62700&I=500CDA7998&o=p&a=0&cc=01
&avf=N&search=alpine
Alpine CDA-7998 is ~ #150.00 cheaper than CDA-9835
Finally, it is best when using a CAP and 2 amps, to only use trhe Cap on the sub amp. The 4 channel amp does not need a CAP and all amps and CAP should be grounded to the same location to minimize noise. Try resetting your sub amp gain as noted earlier and see if this improves performance. Also, check your sub wiring to amp as well. If these subs are both wired to amp in parallel, this will cause the sub amp to shut down at high volume levels.
Let us know what you find out OK?
Swez
PS CompVR... you are to funny my "Little Grasshopper" ! But you have learned a lot in past 6 months and I am proud to have you as a student. Keep up the good work... and fix that darn stick keyboard problem soon huh? SMILE
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