PDA

View Full Version : 4V preamp: worth it?



Golitan11
07-24-2013, 12:32 AM
I have an Alpine SWR-12D4 subwoofer with an Alpine MRX-M110 amplifier and factory speakers (I may upgrade in the future) and I need to change my head unit. I am curently stuck between some from Kenwood (KDC-X397) and Pioneer (DEH-X7500S) because both have 4V preamp models, but for the same price, I can get Bluetooth with a 2.5V preamp (DEH-X6500BT). 4V preamp and Bluetooth models are too expensive for me (130$ is my maximum). So there are my questions:

1. Is a 4V preamp really worth it (more than Bluetooth for my smartphone)? Will it make such a difference with my actual setup?
2. Kenwood and Pioneer have really similar models. Kenwood has more power but Pioneer has a better equalizer. What brand/model is better (even if it is really personal I wanna know your opinions)?

Thanks.

IonRL205
07-24-2013, 12:35 AM
You wouldn't notice a difference using 2v or 4v preouts

Both Kenwood and Pioneer make good decks. I prefer Pioneer but that's only because that's all I've really used.

I would go with the one that you like better.

SounDrive
07-24-2013, 12:45 AM
I have an Alpine SWR-12D4 subwoofer with an Alpine MRX-M110 amplifier and factory speakers (I may upgrade in the future) and I need to change my head unit. I am curently stuck between some from Kenwood (KDC-X397) and Pioneer (DEH-X7500S) because both have 4V preamp models, but for the same price, I can get Bluetooth with a 2.5V preamp (DEH-X6500BT). 4V preamp and Bluetooth models are too expensive for me (130$ is my maximum). So there are my questions:

1. Is a 4V preamp really worth it (more than Bluetooth for my smartphone)? Will it make such a difference with my actual setup?
2. Kenwood and Pioneer have really similar models. Kenwood has more power but Pioneer has a better equalizer. What brand/model is better (even if it is really personal I wanna know your opinions)?

Thanks.

You definitely want the 4V preouts. Without enough preout voltage, you really have to crank the gain on your amp up. It's hard to explain, but it seems like you get a lot more output with higher voltage preouts, even with the amps set the same with a DMM. And also, I personally don't like using bluetooth for music because it doesn't play music at a high bitrate (all of my music is either 320kbps mp3 or in lossless format) - so you lose some sound quality there. Also, completely ignore the power ratings. Kenwood and Pioneer both make good head units. You might consider going used. I got my Pioneer DEH-500UB (was $210 new when they still made it) for somewhere around $100 and it's amazing. 3 sets of 5v preouts, the sound retriever function, iPod USB capatability, etc.

mr_naler
07-24-2013, 01:00 AM
Pioneer DEH-P8400BH

$139 @ sonicelectronix: 3 sets of 4v preouts, 5 band EQ, Bluetooth, and several other goodies. It's a really good deal, especially considering free shipping and discounted install items. I know it's $9 over your maximum, but you can always swap out a couple meals with Ramen and make up the difference. That's what I would do anyhow, I'm kinda cheap though.

Golitan11
07-24-2013, 01:06 AM
Ok thanks. So in what way Kenwood and Pioneer are different then?

SounDrive
07-24-2013, 01:19 AM
Ok thanks. So in what way Kenwood and Pioneer are different then?

The features and looks are about the only difference. The power output isn't going to be noticably different. Read through the product details and that pretty much tells you all of the differences. I've ran both Kenwood and Pioneer head units and both worked well.

Alrojoca
07-24-2013, 01:32 AM
If you need BT go with Pioneer, if not go with Kenwood

tc300
07-24-2013, 02:48 AM
0P spend the money and get a good deck!! Why... Cause its where ur music starts at!!!

Joe562MMA
07-24-2013, 03:22 AM
i noticed a difference in my 4v outputs but to each his own, if u wanna go diff route u can just get a clarion eq or that has 7v pre outs or other similar eq

fasfocus00
07-24-2013, 04:03 AM
there really isn't going to be much of difference between 2 identical deck with 2v and the other having 4v b/c the gain of you amp should be matched to the input voltage. I'll tell you personally on all my own systems I always have some sort of signal processor with a line driver built into it to get a higher pre amp voltage.

SounDrive
07-24-2013, 10:11 AM
I noticed a difference between my 2v preouts in my first HU and the 5v preouts now.

IonRL205
07-24-2013, 10:16 AM
I've never noticed any difference between using 2v or 4v pre outs.

SounDrive
07-24-2013, 10:21 AM
I've never noticed any difference between using 2v or 4v pre outs.

Higher voltage preouts = lower gain setting on amp

Lower gain on amp = less signal noise/distortion because it isn't amplified as much

---------- Post added at 09:21 AM ---------- Previous post was at 09:21 AM ----------


I've never noticed any difference between using 2v or 4v pre outs.

Higher voltage preouts = lower gain setting on amp

Lower gain on amp = less signal noise/distortion because it isn't amplified as much

IonRL205
07-24-2013, 10:29 AM
Higher voltage preouts = lower gain setting on amp

Lower gain on amp = less signal noise/distortion because it isn't amplified as much

---------- Post added at 09:21 AM ---------- Previous post was at 09:21 AM ----------



Higher voltage preouts = lower gain setting on amp

Lower gain on amp = less signal noise/distortion because it isn't amplified as much

Like I said, I've never noticed a difference using 2v or 4v pre outs.

And by difference, I mean a difference in sound

d77543020
07-24-2013, 10:40 AM
same here i had 2volt alpine decks that blew away some of my pioneer 4volt decks in sq

SounDrive
07-24-2013, 10:42 AM
Like I said, I've never noticed a difference using 2v or 4v pre outs.

And by difference, I mean a difference in sound

It depends on the noise in your system. If there's no noise at 2v you won't be getting any benefits, however most setups have at least some noise and higher voltage preouts help to eliminate some of it.

IonRL205
07-24-2013, 10:48 AM
It depends on the noise in your system. If there's no noise at 2v you won't be getting any benefits, however most setups have at least some noise and higher voltage preouts help to eliminate some of it.

There would probably be difference going from say a 2v Dual deck to a 4v Pioneer or Alpine lol

But going from a 2v Pioneer deck to 4v Pioneer, I didn't notice any difference.

SounDrive
07-24-2013, 11:07 AM
There would probably be difference going from say a 2v Dual deck to a 4v Pioneer or Alpine lol

But going from a 2v Pioneer deck to 4v Pioneer, I didn't notice any difference.

Right for the most part. 2v to 5v for me wasn't a huge difference and I doubt most people would hear it but I could hear a little less noise. And I hate noise so that's a pretty big deal to me lol.

But if you do go with the 2v preouts and have noise issues, you can just use a line driver near the head unit to up the preout voltage before any noise is introduced to the signal.

Alrojoca
07-24-2013, 12:25 PM
The kenwood. More power and independent xovers for front and rear.

maylar
07-24-2013, 04:57 PM
You definitely want the 4V preouts. Without enough preout voltage, you really have to crank the gain on your amp up. It's hard to explain, but it seems like you get a lot more output with higher voltage preouts, even with the amps set the same with a DMM..[snip]

Nonsense. Output power is output power.


Higher voltage preouts = lower gain setting on amp

Lower gain on amp = less signal noise/distortion because it isn't amplified as much

This is a common Myth/Legend/Fallacy. The gain control on an amp doesn't affect distortion... it just adjusts the signal level. If set correctly the distortion won't be any different. As for noise, if you have noise on your input signals you're gonna hear it regardless of the gain setting.

There are plenty of SQ systems out there with 2V preouts. This topic has been discussed MANY times here. The big difference is that 4V and 5V units tend to be higher in the product lineups and have other enhancements that actually do make a difference.

RokintypeRs
07-24-2013, 05:29 PM
Nonsense. Output power is output power.



This is a common Myth/Legend/Fallacy. The gain control on an amp doesn't affect distortion... it just adjusts the signal level. If set correctly the distortion won't be any different. As for noise, if you have noise on your input signals you're gonna hear it regardless of the gain setting.

There are plenty of SQ systems out there with 2V preouts. This topic has been discussed MANY times here. The big difference is that 4V and 5V units tend to be higher in the product lineups and have other enhancements that actually do make a difference.

Sorry for disagreeing here but I have had much better luck with a line driver than most. The higher the gain is on an amp, the more amplified and the more signal distortion you will have. Having said that, it can affect distortion to some degree. I have to say the higher the voltage on any head unit being amplified equals less noise and less distortion (if any exist). You also have to take in effect that the stronger the signal, the more output your amp will put out because the signal is being amplified. I'm no expert but I've done my fair share of research and I strongly believe in signal strength.

czand1
07-24-2013, 06:01 PM
4v is nice for noise in the system. Allows u to turn to turn down the gain if you have amps upfront. 2.5 is still high voltage and todays head units rarely get noise with a good ground. Go for the Pioneer with bt and add another amp for the front and new speaks upfront. ihave a new jbl 45x2 and 6.5 and 5.25 cheap.

SounDrive
07-24-2013, 08:44 PM
Nonsense. Output power is output power.



This is a common Myth/Legend/Fallacy. The gain control on an amp doesn't affect distortion... it just adjusts the signal level. If set correctly the distortion won't be any different. As for noise, if you have noise on your input signals you're gonna hear it regardless of the gain setting.

There are plenty of SQ systems out there with 2V preouts. This topic has been discussed MANY times here. The big difference is that 4V and 5V units tend to be higher in the product lineups and have other enhancements that actually do make a difference.

Another argument without much evidence for either side. I've seen it described this way: a 2v or 4v preout will pick up the same amount of signal noise. But the 2v signal needs to be amplified (twice as much) as the 4v signal, so the noise is also amiplified. But like you mentioned, 4v source units are usually higher quality, so it could be either of the two (or a combination).

Also, you won't be reaching anywhere near 2v/4v until you're near the max output of your deck, which is probably clipped unless it's a higher end deck. Higher preout voltage gives you a little more headroom, letting you set your max volume lower when you set your gains

Alrojoca
07-24-2013, 09:44 PM
The question was, is it worth it? I'd say no it is not worth it for the op. Is it better, yes it is better.

To op just needs to decide for himself, BT versus better audio features and power from the HU's amp speaker output.

Which one is it going to be? A lot of good info was shared here already, while others keep debating about the voltage. If you put a silent track and play it with the gains set with a DDM for both 2 and 4 volts you will get slight less hiss with the 4 volts and other marginal benefits with the volume. I just did a listening test. I have an HU with 5 volts RCA s, old school noisy JBL multichannel amp, no noise in between tracks at all, Gains set with DDM, my volume at 15-18 with music is about all I can handle, and it goes to 50. I Put it on aux, no input turn it up to 40 before I hear noticeable audible noise, at max I hear hiss but it does not bother me or makes me turn it down.
Now for cars with external road noise, wind, outside noise etc, I'd say again it's not worth it but it is better. Will the noise be the same with a 2.5 volt RCA's? Maybe, maybe not? is it worth it? I know my volume would need to be at 35 plus instead of 12-14

04murdalanche
07-24-2013, 10:01 PM
you guys are high as hell...

ive noticed a huge hugh difference in going from a alpine 9856, to akenwood x994, 2v pre outs to 4 v preouts, was like night and day... then went to a 80prs and it was again, a huge improvement, now i have a RF 360.3 which i set it to put out 6.5v pre outs to my amps, and again.... a huge difference.

Buck
07-24-2013, 10:58 PM
I HATE 2v radios. A lot of times with amps you have to crank the gain up all the way.

Alrojoca
07-25-2013, 11:10 AM
I agree, I would not buy anything below 4 volts, just a preference. I never tried a 2 volt HU in my set up to notice the difference and I'm sure it will be there.

Again with the op having a 1200 watt amp, the amp will not sweat having the gains higher with 2 volt RCA s assuming he wants BT over 4 volts RCAs, maybe we will never know or hear from him, just like 99% of threads asking for help.

tc300
07-25-2013, 11:34 AM
Still baffles me people think they can skim on price and get a cheap deck but they have over $1000 in subs and amp(s)....??!??! SMH

maylar
07-25-2013, 01:24 PM
Sorry for disagreeing here but I have had much better luck with a line driver than most. The higher the gain is on an amp, the more amplified and the more signal distortion you will have. Having said that, it can affect distortion to some degree. I have to say the higher the voltage on any head unit being amplified equals less noise and less distortion (if any exist). You also have to take in effect that the stronger the signal, the more output your amp will put out because the signal is being amplified. I'm no expert but I've done my fair share of research and I strongly believe in signal strength.

Bolded statements above are simply not true. But they're very common beliefs in car audio. There are also people who think that higher gain setting makes your amp 'work harder' and run hotter.


Another argument without much evidence for either side. I've seen it described this way: a 2v or 4v preout will pick up the same amount of signal noise. But the 2v signal needs to be amplified (twice as much) as the 4v signal, so the noise is also amiplified.

This is true. But for a typical install you'd never hear the difference. The noises we typically deal with are nasty things like engine ignition noises and alternator whine which are unacceptable at ANY level. Those things need to be addressed at the source.

The OP is inquiring about mid priced mass market HU models. My advice is don't make the choice just on preout voltage. If he was building an SQ comp vehicle my advice would be different. Note that a lot of Alpine's HU's still have 2V preouts.


Also, you won't be reaching anywhere near 2v/4v until you're near the max output of your deck, which is probably clipped unless it's a higher end deck. Higher preout voltage gives you a little more headroom, letting you set your max volume lower when you set your gains

The only issue I've ever had with low preouts is that with volume at 80% (unclipped), sub level at 80% (for headroom on the fly) and a -5dB source I couldn't reach full power on the amp even at full gain. Having 4V would help for that. So would having an amp that had more gain.


you guys are high as hell...

ive noticed a huge hugh difference in going from a alpine 9856, to akenwood x994, 2v pre outs to 4 v preouts, was like night and day... then went to a 80prs and it was again, a huge improvement, now i have a RF 360.3 which i set it to put out 6.5v pre outs to my amps, and again.... a huge difference.

As we've said, there are major differences in HU performance but it's not all about preout voltage.

04murdalanche
07-25-2013, 04:19 PM
Bolded statements above are simply not true. But they're very common beliefs in car audio. There are also people who think that higher gain setting makes your amp 'work harder' and run hotter.



This is true. But for a typical install you'd never hear the difference. The noises we typically deal with are nasty things like engine ignition noises and alternator whine which are unacceptable at ANY level. Those things need to be addressed at the source.

The OP is inquiring about mid priced mass market HU models. My advice is don't make the choice just on preout voltage. If he was building an SQ comp vehicle my advice would be different. Note that a lot of Alpine's HU's still have 2V preouts.



The only issue I've ever had with low preouts is that with volume at 80% (unclipped), sub level at 80% (for headroom on the fly) and a -5dB source I couldn't reach full power on the amp even at full gain. Having 4V would help for that. So would having an amp that had more gain.



As we've said, there are major differences in HU performance but it's not all about preout voltage.

Well if they are directly correlated then id say out put voltage has a decent amount to do with it, among other things..

Golitan11
07-25-2013, 07:45 PM
@Alrojoca Don't worry you will have news from me, just like 1% of threads asking for help ;)

No but seriously thanks for all your help guys. I think I will go for the 2012 model of headunit from Pioneer, which has all the features I want and even more for a raisonable price (DEH-P8400BH, 140$). I may also choose the 2013 model with only 4V preamp (DEH-X7500S, 125$; or the Kenwood equivalent: KDC-X397, 125$), but for that price difference, I think I may go with the 2012 one (I don't think there is much difference between the 2012 and the 2013 models so).