head unit

[///M5 2,833]

I think you're misinterpreting what I'm saying. For equal output, the gain on the amp will be higher with a head unit with 2v preouts vs a head unit with 4v preouts. If both sources have an equal amount of signal noise, the noise from the 2v preout will be amplified more due to the higher gain setting. This is mostly applicable for RCA noise, because any noise before the RCA is going to vary depending on the head unit and other factors.

 

Also, I never said swapping your head unit was the best way to get rid of RCA noise, because it is not. It's simply one way to reduce it but not nearly the best option; however, I wouldn't go quite as far as to call it ineffective. The best solution for RCA noise is to purchase or build properly shielded RCA interconnects and/or route the cables away from any sources of noise.

I think you have confused yourself.

Describe your concern in dB and you'll understand. If you have xdB of music and ydB of noise whether it is at 2v or 4v and you amplify it, what happens?

And no, you didn't say swap your headunit but the reasons you are using for a 4v instead of a 2v don't exist which means that by definition your recommendation of a 4v hu for reducing noise is saying to buy one to do that. Glad you realized actually fixing the source of the problem instead of attempting to put a band aid on it is a good idea.

 

I haven't confused myself, but I appear to have confused you.

 

I presented facts showing how higher voltage preouts are superior for minimizing some sources of noise. I'm talking about noise introduced after the preout source, not from the preout source itself. Personally, I don't have to worry about such noise because of my choice in interconnects and routing, but many people do have noise issues. A head unit that costs slightly more will often be more practical than buying multiple sets of high priced RCA interconnects. Yes, the noise will still be there, but it won't be as noticable.

Ah, so now you finally just come around and admit it. No need. Curious why you recommended it then?

[Impious 1,476]

I presented facts showing how higher voltage preouts are superior for minimizing some sources of noise. I'm talking about noise introduced after the preout source, not from the preout source itself..

Just to clarify, higher preamp voltages do not "minimize" the source of noise. Higher preamp voltages increase the signal to noise ratio (SNR).....the level of the induced noise is the same, but the level of the signal is higher so the SNR is also higher. Saying the noise is minimized implies that the higher voltage has some inherent ability to "reject" some of the noise, reducing it's level....which it does not. The noise is the same, but the SNR has increased.

M5's point was that in the cases where you have an audible amount of induced noise, the problem is the signal cables or routing near sources of noise in the vehicle (which does not include the amp's power cable), and increasing the voltage of the signal is masking the problem rather than fixing it.

[Tenacious 32]

I presented facts showing how higher voltage preouts are superior for minimizing some sources of noise. I'm talking about noise introduced after the preout source, not from the preout source itself..

Just to clarify, higher preamp voltages do not "minimize" the source of noise. Higher preamp voltages increase the signal to noise ratio (SNR).....the level of the induced noise is the same, but the level of the signal is higher so the SNR is also higher. Saying the noise is minimized implies that the higher voltage has some inherent ability to "reject" some of the noise, reducing it's level....which it does not. The noise is the same, but the SNR has increased.

M5's point was that in the cases where you have an audible amount of induced noise, the problem is the signal cables or routing near sources of noise in the vehicle (which does not include the amp's power cable), and increasing the voltage of the signal is masking the problem rather than fixing it.

I know this, and that's what I said. The final noise is less (at the same volume) from the 4v preouts, and yes, that is because of the higher SNR. I never said anything about some sort of fairy dust that accompanies higher voltage preouts and repels noise. I said that because the signal is amplified more, the noise is amplified more... I guess that assuming my point would be made was too generous of me.

 

And either way, masking the problem is still better than ignoring it altogether.

[Tenacious 32]

 

 

I think you're misinterpreting what I'm saying. For equal output, the gain on the amp will be higher with a head unit with 2v preouts vs a head unit with 4v preouts. If both sources have an equal amount of signal noise, the noise from the 2v preout will be amplified more due to the higher gain setting. This is mostly applicable for RCA noise, because any noise before the RCA is going to vary depending on the head unit and other factors.

 

Also, I never said swapping your head unit was the best way to get rid of RCA noise, because it is not. It's simply one way to reduce it but not nearly the best option; however, I wouldn't go quite as far as to call it ineffective. The best solution for RCA noise is to purchase or build properly shielded RCA interconnects and/or route the cables away from any sources of noise.

I think you have confused yourself.

Describe your concern in dB and you'll understand. If you have xdB of music and ydB of noise whether it is at 2v or 4v and you amplify it, what happens?

And no, you didn't say swap your headunit but the reasons you are using for a 4v instead of a 2v don't exist which means that by definition your recommendation of a 4v hu for reducing noise is saying to buy one to do that. Glad you realized actually fixing the source of the problem instead of attempting to put a band aid on it is a good idea.

 

 

I haven't confused myself, but I appear to have confused you.

 

I presented facts showing how higher voltage preouts are superior for minimizing some sources of noise. I'm talking about noise introduced after the preout source, not from the preout source itself. Personally, I don't have to worry about such noise because of my choice in interconnects and routing, but many people do have noise issues. A head unit that costs slightly more will often be more practical than buying multiple sets of high priced RCA interconnects. Yes, the noise will still be there, but it won't be as noticable.

 

Ah, so now you finally just come around and admit it. No need. Curious why you recommended it then?

If the OP were to have minimal RCA noise, he may not notice it with higher voltage preouts. It's something that you'd have to look at on an install to install basis. Also, head units with higher voltage preouts are generally higher quality... Although there is not a direct correlation and that's a subject for another thread.

[///M5 2,833]

Stop confusing things. The only noise it helps with according to your posts is IF you are a poor installer and have RCA induced noise. Otherwise the SNR stays the same. So by saying a 4v hu will help reduce noise over a 2v hu you are trying to solve the RCA induced noise (that you yourself say you don't have) by swapping headunits. Completely bass akwards methodology if you ask anyone scientific. If you create a problem, solve the problem don't mask it.

As for the higher quality, that is subjective unless you define what higher quality is. Pretty sure you haven't measured the frequency response of both 2v and 4v units to say that. And if there is no difference in FR, what is this quality you speak of. Also not so interesting to see you waffle and change arguments part way through. If it is for noise, define this noise otherwise your recommendation is dubious at best.

[Tenacious 32]

Stop confusing things. The only noise it helps with according to your posts is IF you are a poor installer and have RCA induced noise. Otherwise the SNR stays the same. So by saying a 4v hu will help reduce noise over a 2v hu you are trying to solve the RCA induced noise (that you yourself say you don't have) by swapping headunits. Completely bass akwards methodology if you ask anyone scientific. If you create a problem, solve the problem don't mask it.

As for the higher quality, that is subjective unless you define what higher quality is. Pretty sure you haven't measured the frequency response of both 2v and 4v units to say that. And if there is no difference in FR, what is this quality you speak of. Also not so interesting to see you waffle and change arguments part way through. If it is for noise, define this noise otherwise your recommendation is dubious at best.

You're beating a dead horse by telling me that I'm stupid for trying to minimize RCA noise via the head unit. Quite honestly, your negative opinion on the matter isn't needed here. No matter what you say about it, it still works.

 

Also, I said generally, and I said it was not a direct correlation. Quit putting words into my mouth.

[Notorious97200 339]

If you have bad noise in your system, fix it !

Don't take out the rca cable from amp or hu when playing and you should not have noise issues if everything is well done

 

The mods, here, know their things, don't need to argue with them !

[///M5 2,833]

You're beating a dead horse by telling me that I'm stupid for trying to minimize RCA noise via the head unit. Quite honestly, your negative opinion on the matter isn't needed here. No matter what you say about it, it still works.

 

Also, I said generally, and I said it was not a direct correlation. Quit putting words into my mouth.

I put no words in your mouth, that is all you. You claim it works, but then works for what?

As a reminder, this is what started this all.

It actually does make a difference in many installs.. Not always, but if you have noise, 2v preouts will require the noise to be amplified twice as much as 4v outputs.

So again, if you have NO RCA induced noise there is no benefit in upping your voltage now is there?

[///M5 2,833]

Your argument is even funnier when you consider how long you spend above 2v on a headunit that even has 4v out. Log volume controls don't really allow the dubious benefit you even describe unless you are full bore in which case the noise won't be an issue anyways.

I'm just trying to make sure the OP doesn't get confused by a recommendation that could be meaningless to him. So many poor old wives tales and snake oil in audio that doesn't fly here.

[Tenacious 32]

If you have bad noise in your system, fix it !

Don't take out the rca cable from amp or hu when playing and you should not have noise issues if everything is well done

 

The mods, here, know their things, don't need to argue with them !

I know what I'm talking about as well, I'm not going to let someone walk all over me simply because of the color of their username. I stated that higher voltage preouts reduce the overall effect of RCA noise. How hard is that to understand?

[Tenacious 32]

Your argument is even funnier when you consider how long you spend above 2v on a headunit that even has 4v out. Log volume controls don't really allow the dubious benefit you even describe unless you are full bore in which case the noise won't be an issue anyways.

I'm just trying to make sure the OP doesn't get confused by a recommendation that could be meaningless to him. So many poor old wives tales and snake oil in audio that doesn't fly here.

And the 2v head unit will be putting out roughly half as much voltage as the 4v head unit at any given volume. My argument still stands.

 

I don't quite consider something an "old wives tale" or "snake oil" if it is a fact.

Edited January 2, 2014 by SantaClawZ

[///M5 2,833]

Your argument is even funnier when you consider how long you spend above 2v on a headunit that even has 4v out. Log volume controls don't really allow the dubious benefit you even describe unless you are full bore in which case the noise won't be an issue anyways.

I'm just trying to make sure the OP doesn't get confused by a recommendation that could be meaningless to him. So many poor old wives tales and snake oil in audio that doesn't fly here.

And the 2v head unit will be putting out roughly half as much voltage as the 4v head unit at any given volume. My argument still stands.

 

I don't quite consider something an "old wives tale" or "snake oil" if it is a fact.

First off perhaps you should compare voltage to dB's. I tried to hint that to you before as it will be insightful...

Secondly, if the noise is the SAME (which if it is RCA induced whether you change head unit or not) the ONLY time there will be a difference is when the headunit exceeds 2v's. Otherwise the SNR will be exact same noise level as compared to the output level, so ie, below 2v there is no difference.

[Tenacious 32]

And the amp's gain will still be set higher for the 2v signal.

[pmureika 31]

And the amp's gain will still be set higher for the 2v signal.

So I should sell my JVC 2 volt hu and get a 4 volt even tough I have no noise?

[Tenacious 32]

I never said that. If RCA noise was an issue and it wouldn't be an inconvenience, then sure.

[pmureika 31]

I never said that. If RCA noise was an issue and it wouldn't be an inconvenience, then sure.

I would say if you do have rca noise you have a install problem.

 

2 or 4 volts!

[///M5 2,833]

And the amp's gain will still be set higher for the 2v signal.

Aha, I now understand why you are confused. Ignore the amp. It doesn't matter for this discussion on headunit pre voltage. Assuming it does its job it will only amplify the signal and the noise equally. This means of course that the SNR ratio on the lines going into the amp are what will make it different. ie, if you have a given RCA induced noise whether the headunit outputs 2v or 4v it will be the same ratio all the way until your knob exceeds the 2v the other headunit can output.

[Impious 1,476]

I presented facts showing how higher voltage preouts are superior for minimizing some sources of noise. I'm talking about noise introduced after the preout source, not from the preout source itself..

Just to clarify, higher preamp voltages do not "minimize" the source of noise. Higher preamp voltages increase the signal to noise ratio (SNR).....the level of the induced noise is the same, but the level of the signal is higher so the SNR is also higher. Saying the noise is minimized implies that the higher voltage has some inherent ability to "reject" some of the noise, reducing it's level....which it does not. The noise is the same, but the SNR has increased.

M5's point was that in the cases where you have an audible amount of induced noise, the problem is the signal cables or routing near sources of noise in the vehicle (which does not include the amp's power cable), and increasing the voltage of the signal is masking the problem rather than fixing it.

I know this, and that's what I said. The final noise is less (at the same volume) from the 4v preouts, and yes, that is because of the higher SNR. I never said anything about some sort of fairy dust that accompanies higher voltage preouts and repels noise. I said that because the signal is amplified more, the noise is amplified more... I guess that assuming my point would be made was too generous of me.

 

And either way, masking the problem is still better than ignoring it altogether.

That's not what you said. You've yet to use the phrase SNR until you quoted my post, which if that's what you meant then it would have been a wise choice of words. When we are discussing signal transmission, which is what we are doing when we are discussing preamp voltage levels, minimizing noise would mean reducing the level of noise present in the signal.

And I don't recall anyone suggesting we just ignore the problem. Silly thing to say, not even sure where that came from.

[coot 4]

well i ended up going with the kenwood if anyone was wondering lol. Got the amp ordered today as well. wiring showed up yersterday so now just need head, amp and sub to show up

[Impious 1,476]

well i ended up going with the kenwood if anyone was wondering lol. Got the amp ordered today as well. wiring showed up yersterday so now just need head, amp and sub to show up

Who the hell are you? Get the hell out of this thread!

Oh shit, you're the OP. My bad. Forgot where this all started.

Hope it works out for. I haven't a clue about any of the units you mentioned as I don't stay current on HU's.....so I wasn't any help on selecting one.

[garychurch84 127]

Haha thread went a different path than what OP was holding for