Hey Guys,
In some previous posts I explained my problems with alternator noise.I checked everything that Swez and others had told me to check,i.e. grounds,RCAs etc. Yes, most of it goes away when I turned down the gain on the 4-channel Profile(It's now at about one quarter of the way clockwise or about 2.2- 2.5 v) The Pioneer HU is a 2.2v output.The problem is I've also lost alot of volume. I've been looking at line drivers/EQ's like this Clarion. Anyone have any experince w/ these?
Thanx, Tego
http://www.cardomain.com/item/CLAEQS744
Replies (7)
uochronos on 12/21/2004 01:37:38
if your HU is 2.2volts then your amp should be set at 2.2 or higher not lower or you cane asily start cliping when you get 2volt or less on the gain.. if your amp cant put out enough power with the gain set right then it sounds like you arnt happy with the amps capabilities sounds like the whining noise come when you are trying to magnify the signal too much and sound already existant is being magnified till you can here it..
a line driver may work here but i know things like active crossovers and EQ's added into a system with noise already usualy magnify the noise even more making it louder.
swez and others i'm sure can tell you more but thats my 2 cents
Chronos
swez on 12/21/2004 12:45:12
Agreed, if your HU is 2.2 volts, the amp gains should be set pretty close to that to get full power from the amps. Try adjusting your amp gains to where the noise comes on, then back off the gains until you cannot hear the noise. That's your reference point. If SPL is still too low, need a better amp with more RMS power to drive your speakers to potential w/o noise or clipping the amp.
BTW, a Line driver may not help too much here. If the LD can take a 2 volt signal and kick it up to 4-6 volts, but the amp can only take 4 volts... the amp will go into massive clipping. If you set LD to 4.0 volts and amp to match, pretty much right back where you started... a weak amp.
Swez
PS What model HU, speakers and Profile amp are you rinning here?
montego_27 on 12/21/2004 14:08:12
Pioneer DEH-p4600mp HU 2.2v
Infinity 4x6'sin dash
Polk 6x9's in rear deck
Tweets running right off the HU up near visors
Profile HA 740- 4-channel 4x 60 Rms THD<0.07@RMS 200mv-7v low level input- RCA input impedance 20k ohms -signal to noise 100db
RF Sub amp is daisy chained off of 4-channel
2 JL 10's in box in trunk (love em)
swez on 12/21/2004 17:34:57
Well, a 60 x 4 amp should be strong enough to push your interior speakers to decent SPL levels. (~100 -103 dB of SPL) That's pretty loud stuff in a small car. If you cannot get enough gain from that amp at ~2 volts, drop down a hair and see if the noise comes back.
If you have 2 amps daisy chained together, that may be part of the issue... the sub amp is sharing a portion of that 2.2 volts. You may have use for a good LD here afterall.
Swez
ttocs on 12/21/2004 18:53:40
just curious if the signal and pwr wires have been seperated?
I have had good luch with the PG line driver as well, but be sure not to mount it to the chassis, they don't like that....
montego_27 on 12/21/2004 19:09:52
Yes the signal and power wires were run along different sides.(Good quality shielded RCAs along with good power and ground wires).Some of the EQs I've been looking at seem to have a built in line driver (around 7-8v outputs).Is an EQ w/ this output a better option than just a straight line driver?I think I would have to purchase 2 line drivers because of the 4-channel amp.
Thanx,Tego
swez on 12/21/2004 20:32:32
Some of the better EQ's will give you a built in Line driver as well. The thing is, if there is noise at the HU, it may just pass through the EQ and into amps and speakers too.
Some of the better quality EQ's have built in isolation transformers and noise blocking filters. This would solve low gain issues and eliminate most, if not all signal line noise. The best products I know about are from Audio Control. Have a look and see what ya like:
http://www.audiocontrol.com/MobileAudio/Products/index.html
Swez
In some previous posts I explained my problems with alternator noise.I checked everything that Swez and others had told me to check,i.e. grounds,RCAs etc. Yes, most of it goes away when I turned down the gain on the 4-channel Profile(It's now at about one quarter of the way clockwise or about 2.2- 2.5 v) The Pioneer HU is a 2.2v output.The problem is I've also lost alot of volume. I've been looking at line drivers/EQ's like this Clarion. Anyone have any experince w/ these?
Thanx, Tego
http://www.cardomain.com/item/CLAEQS744
Replies (7)
uochronos on 12/21/2004 01:37:38
if your HU is 2.2volts then your amp should be set at 2.2 or higher not lower or you cane asily start cliping when you get 2volt or less on the gain.. if your amp cant put out enough power with the gain set right then it sounds like you arnt happy with the amps capabilities sounds like the whining noise come when you are trying to magnify the signal too much and sound already existant is being magnified till you can here it..
a line driver may work here but i know things like active crossovers and EQ's added into a system with noise already usualy magnify the noise even more making it louder.
swez and others i'm sure can tell you more but thats my 2 cents
Chronos
swez on 12/21/2004 12:45:12
Agreed, if your HU is 2.2 volts, the amp gains should be set pretty close to that to get full power from the amps. Try adjusting your amp gains to where the noise comes on, then back off the gains until you cannot hear the noise. That's your reference point. If SPL is still too low, need a better amp with more RMS power to drive your speakers to potential w/o noise or clipping the amp.
BTW, a Line driver may not help too much here. If the LD can take a 2 volt signal and kick it up to 4-6 volts, but the amp can only take 4 volts... the amp will go into massive clipping. If you set LD to 4.0 volts and amp to match, pretty much right back where you started... a weak amp.
Swez
PS What model HU, speakers and Profile amp are you rinning here?
montego_27 on 12/21/2004 14:08:12
Pioneer DEH-p4600mp HU 2.2v
Infinity 4x6'sin dash
Polk 6x9's in rear deck
Tweets running right off the HU up near visors
Profile HA 740- 4-channel 4x 60 Rms THD<0.07@RMS 200mv-7v low level input- RCA input impedance 20k ohms -signal to noise 100db
RF Sub amp is daisy chained off of 4-channel
2 JL 10's in box in trunk (love em)
swez on 12/21/2004 17:34:57
Well, a 60 x 4 amp should be strong enough to push your interior speakers to decent SPL levels. (~100 -103 dB of SPL) That's pretty loud stuff in a small car. If you cannot get enough gain from that amp at ~2 volts, drop down a hair and see if the noise comes back.
If you have 2 amps daisy chained together, that may be part of the issue... the sub amp is sharing a portion of that 2.2 volts. You may have use for a good LD here afterall.
Swez
ttocs on 12/21/2004 18:53:40
just curious if the signal and pwr wires have been seperated?
I have had good luch with the PG line driver as well, but be sure not to mount it to the chassis, they don't like that....
montego_27 on 12/21/2004 19:09:52
Yes the signal and power wires were run along different sides.(Good quality shielded RCAs along with good power and ground wires).Some of the EQs I've been looking at seem to have a built in line driver (around 7-8v outputs).Is an EQ w/ this output a better option than just a straight line driver?I think I would have to purchase 2 line drivers because of the 4-channel amp.
Thanx,Tego
swez on 12/21/2004 20:32:32
Some of the better EQ's will give you a built in Line driver as well. The thing is, if there is noise at the HU, it may just pass through the EQ and into amps and speakers too.
Some of the better quality EQ's have built in isolation transformers and noise blocking filters. This would solve low gain issues and eliminate most, if not all signal line noise. The best products I know about are from Audio Control. Have a look and see what ya like:
http://www.audiocontrol.com/MobileAudio/Products/index.html
Swez
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