sound processor, eq, line driver?

Hi Guys,

I have a JVC KD-NX5000 headunit, and the preouts put out 2V.  I'm running two amp, a PG Xenon 1200.1 for my 15 inch RE Audio HC sub and a old school sony amp for my mids and highs.  Would it be a good idea to run a sound processor? EQ? or Line Driver? to enhance the SQ and/or higher preout voltage.

thanks guys, any opinions welcome...

A friend of mine, Chris Brunhaver of BNG, once described signal processors in some hands as "giving a monkey a gun".  In other words, if you don't know what you are doing you can easily screw things up with one. 

My question to you; do you have some audible problem in your system that you are trying to add equipment to solve?

well my HU will be at volume 40 and i know my sub can be heard louder but it seems its not get a good signal, i might have to get a new HU maybe.

trancelovin65 wrote:

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well my HU will be at volume 40 and i know my sub can be heard louder but it seems its not get a good signal, i might have to get a new HU maybe.

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haemphyst wrote:

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3: Why does everybody think you have to have a higher output voltage? If your head's output falls within the range of the amplifier's acceptable input, you WILL get full output from the amplifier, and too high a voltage will drive the amp to clipping far sooner, DECREASING your overall sound quality, and risking damage to your drivers.

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I'm not saying that higher voltage is needed, but IMO it is better having a 4V (or more) pre out on the HU than 2V. I have used a couple Eclipse decks with 8v pre outs and switch to an alpine w200 with a 2v pre out and noticed a significan different, both audibly and on the meter (term lab). This can be adjust by increasing the gains (if going from 8V to 2V), however, your amplifier then runs hotter and will not be as efficient. Efficiency is the key. The cooler your equipment runs, the more efficient it will be, and the better performance you will get out of it.

I highly recommend getting a deck with at least 4V pre outs to anyone and if you have a deck with 2V pre outs, such as mine, a processor is a must (especially for the w200 and the w205, otherwise the deck is crap without it).

As for the issue, it is a power issue. If gains are set high (I would never go past 3/4), then the sub needs more power, provided it can handle it.

donpisto wrote:

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I'm not saying that higher voltage is needed, but IMO it is better having a 4V (or more) pre out on the HU than 2V. I have used a couple Eclipse decks with 8v pre outs and switch to an alpine w200 with a 2v pre out and noticed a significan different, both audibly and on the meter (term lab). This can be adjust by increasing the gains (if going from 8V to 2V), however, your amplifier then runs hotter and will not be as efficient. Efficiency is the key. The cooler your equipment runs, the more efficient it will be, and the better performance you will get out of it.

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donpisto wrote:

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I highly recommend getting a deck with at least 4V pre outs to anyone and if you have a deck with 2V pre outs, such as mine, a processor is a must (especially for the w200 and the w205, otherwise the deck is crap without it).

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donpisto wrote:

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As for the issue, it is a power issue. If gains are set high (I would never go past 3/4), then the sub needs more power, provided it can handle it.

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haemphyst wrote:

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if an amp "is running hotter", it ISN'T because you turned the gain up, it's because you are asking it to do more.

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haemphyst wrote:

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No, it isn't necessary, and no, the deck ISN'T crap without it... The crap comes when the installer/user doesn't know how to adjust signal levels properly. As I said above, if your amplifier's acceptable input range includes the RMS output voltage available from the deck, you WILL get full power from the amplifier, even without any kind of "processing", "line driving", or "equalization", no matter what your definition of those are.

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haemphyst wrote:

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Your generalizations are trouble, man! You can't GUARANTEE that, I still maintain enclosure is more important, and more likely the case... He's got 1200 watts for a single driver, I'd say to look into a different box before spending more money on an amplifier that may give MARGINALLY (ONLY 3dB if he goes to 2400 watts - a barely audible difference!) more output or not.

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As mentioned before, if the input level (gain) of the amp is matched to the output of the HU then the amp will put out max power.

If you have an amp with an adjustable gain of 8v - 2v, then a HU that puts out anything in between that will allow the amp to reach full power. So, an amp with an adjustable gain of 8v - 2v can reach full power with EITHER a HU that puts out 8v OR 2v, period. This eliminates the use for line drivers etc...

jmelton86 wrote:

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As mentioned before, if the input level (gain) of the amp is matched to the output of the HU then the amp will put out max power.

If you have an amp with an adjustable gain of 8v - 2v, then a HU that puts out anything in between that will allow the amp to reach full power. So, an amp with an adjustable gain of 8v - 2v can reach full power with EITHER a HU that puts out 8v OR 2v, period. This eliminates the use for line drivers etc...

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What amps do you know of that won't accept less than 2v input?

I walked outside and checked my sub amps. They accept from 8v - .003v. Meaning, even 3/1000 of a volt will still give the amp enough to reach full power. My front stage amp goes from 5v - .2v.

Do you see what we're saying?

donpisto wrote:

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jmelton86 wrote:

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As mentioned before, if the input level (gain) of the amp is matched to the output of the HU then the amp will put out max power.

If you have an amp with an adjustable gain of 8v - 2v, then a HU that puts out anything in between that will allow the amp to reach full power. So, an amp with an adjustable gain of 8v - 2v can reach full power with EITHER a HU that puts out 8v OR 2v, period. This eliminates the use for line drivers etc...

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I understand what you're saying, but take for example this situation: With the current setup, you have a deck with say 5V preouts, the sub can handle 1,000w and you have an amp that puts out 500w. It will surely take all that amp has even at full gain (provided they are both quality products). If you have the gain set currently at 3/4 with the 5v pre out, going to a deck with a 2v preout, you would have to compensate for that and would have to turn up the gain to get the same output, and it would most likely be beyond full gain.

Same scenario, except with the 5v deck you're gains are set at below 1/4. If you go down to the 2v pre out deck then you'd need to turn the gain up, say to 1/2 (or whatever it is, but it needs to be turned up to get the same output).

Not sure what I'm saying makes sense, but both scenarios will have the following effect: Lower the gain is, the cooler it will be, the less current it will pull, the more efficient it will run. Also running an amp at a 4 ohm load rather than a 1 ohm load will make the amp run cooler. If your amp can put out the power the sub needs at a higher impedence, it is better to stick with that. I used to have an RL-p 18 and I have an RF T30001bd for it. The sub really only needs 1k. It can surely take 1.5-2k, but it is not necessary. Running at 1 ohm and 4 ohms was a major difference. The amplifier itself is built real well so it hardly gets hot. But I notice a difference in the current it draws. One can easily notice if they are drawing too much current by checking the voltage at the amplifier with a DMM. If you don't have one, the simply having your headlights on at night and parked against wall and playing the system and higher volumes and adjust the gains will clearly show you when you are pulling more current. If you have a stout electrical system or aren't running much power, then you really won't notice the difference. But if you are running 3k with a stock alternator and a single battery, there will be a MAJOR change with the settings of the gains.

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You have some things mixed up here. Regardless of how many stars and posts I have, I can assuredly tell you, you have been misinformed some where along the line.

1. As mentioned above, the gain is a level matching system. Your statements are contradictory in the above post. So you use an Eclispe deck that happens to have 8 volt pre-outs, great, you need only crack the gain on you amp a hair (read; you adjusted the gain ever so slightly), for it to reach FULL output wattage of the amp (Not going to adress impedance yet).

Here is the contradiction, you now swap that Eclispe deck with some off brand deck that only has 2 volt outputs, now in order for the to be level matched  and produce FULL wattage output, you must crank the gain, and again it is producing the same wattage as when the gain was only cracked with the 8 volt input.

Oh wait, the amp produces full power either way the gain is set (only when leve matched properly)?? Yes, so the amp works at the same "stress" level when levels are matched! It doesn't matter where the gain is set!

2. Yes, of course changing (lowering, going from a 4 ohm load to a 1 ohm load for eg. ) the impedance presented to the amp will require the amp to draw more current from its power source (cars charging system) hence the light dimming, etc.

donpisto wrote:

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I'm not saying that higher voltage is needed, but IMO it is better having a 4V (or more) pre out on the HU than 2V. I have used a couple Eclipse decks with 8v pre outs and switch to an alpine w200 with a 2v pre out and noticed a significan different, both audibly and on the meter (term lab). This can be adjust by increasing the gains (if going from 8V to 2V), however, your amplifier then runs hotter and will not be as efficient. Efficiency is the key. The cooler your equipment runs, the more efficient it will be, and the better performance you will get out of it.

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I don't think you understand the concept of a gain control.  It isn't a volume control.  It is there to match the amplifier to the head unit being used.  Since output voltage isn't regulated like it is in home audio, signal levels from head units will be different, therefore an amplifier needs a gain knob to adjust to those differences.  An amplifier producing 500 watts with a 2 volt input will be just as efficient and produce the same amount of heat as an amplifier producing 500 watts with an 8 volt head unit.  The difference is the gain will be set at different points.

Here's a great link that explains gain controls: https://www.bcae1.com/gaincon2.htm

donpisto wrote:

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I highly recommend getting a deck with at least 4V pre outs to anyone and if you have a deck with 2V pre outs, such as mine, a processor is a must (especially for the w200 and the w205, otherwise the deck is crap without it).

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That's not true.  My deck/processor combination has a pre-out voltage less than 1 volt (as was seen with an oscilloscope) and I'd bet it produces cleaner sound than your 4v pre-out head unit.  Pre-out voltage is a marketing gimmick pure and simple.  And I believe it is responsible for quite a bit of confusion and damaged equipment throughout the industry because so many installers don't know how to set gains correctly, much less the DIY'ers out there installing their own equipment.

donpisto wrote:

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As for the issue, it is a power issue. If gains are set high (I would never go past 3/4), then the sub needs more power, provided it can handle it.

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Why wouldn't you go past 3/4 if the amplifier never clips?  I set my gains with an oscilloscope and found I could turn the gains all the way up and never get clipping.  What do you think will happen by doing this?

donpisto wrote:

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Oh really? So tell me, I guess I should be able to fine tune my system by adjusting the bass and treble from -7 to +7? That is enough? I think not. It has no EQ that is usefull without the H701 processor. Do you see any SQ guys running the W200 or W205 without the processor? Can you do time alignment and set your soundstage without the processor? The deck, is really useless without the processor if you want the audio to sound right. I'm currently using it without the processor and it sounds okay.... and please don't tell me adjust the bass and treble is because I am not setting it right, you need more than that. You need to set crossover points and adjust the slope on them as well.

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For most people adjustments with bass and treble should be enough as they don't know what they are doing.  A processor in the wrong hands (the monkey I described above) can do far more damage to the sound with a tool like that than good.  Give a paint brush to a kindergartener and all you get is a mess.  But that brush in the hands of someone who knows what they are doing gives us the Sistine Chapel. 

donpisto wrote:

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  Only 3 dB huh? You think that's not alot? Wow, you got some learning to do. 3 dB is more than "a barely audible difference". I have ran several setups, ran different amps on the same subs, ran different subs on same amps, whatever combination you can think of. I can easily notice the difference of even even 0.5 dB. How do I know this? I did a 141.2 dB on the TL on a DD 9515 on a treo ssx 1500.1 then went to a kicker zx 2500.1 and did a 140.8. With music you can easily tell the difference.

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There is a lot more going on there beyond the simple output differences.  You are talking about two different subs with different harmonic distortion characteristics and different frequency responses.  However with the same sub, try swapping an amplifier with one that produces twice the power and you will be surprised at how small the jump in audible output really is.  I know I was when I went from a Soundstream Reference 500 to my Arc 1500dr on my Brahma 10. 

donpisto wrote:

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  Also, 3 dB is theoretically double the loudness. It is a SIGNIFICANT difference.

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Actually 10 dB is double the loudness. 

donpisto wrote:

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  Again, do a little research and get some experience before you blab your mouth. Having a higher post count doesn't mean you know more ;)

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Actually Dave is highly respected around here because of the extensive research he does and the experience he has.  It helps having friends who happen to be engineers at Harman Kardon.  You really need to pick your fights more wisely.  This forum isn't like many of the others, with teenage kids blabbing their mouths trying to sound like they know something.  Many of the people here have extensive backgrounds in this field. 

Steven Kephart wrote:

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I don't think you understand the concept of a gain control. It isn't a volume control. It is there to match the amplifier to the head unit being used. Since output voltage isn't regulated like it is in home audio, signal levels from head units will be different, therefore an amplifier needs a gain knob to adjust to those differences. An amplifier producing 500 watts with a 2 volt input will be just as efficient and produce the same amount of heat as an amplifier producing 500 watts with an 8 volt head unit. The difference is the gain will be set at different points.

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Steven Kephart wrote:

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Why wouldn't you go past 3/4 if the amplifier never clips? I set my gains with an oscilloscope and found I could turn the gains all the way up and never get clipping. What do you think will happen by doing this?

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Steven Kephart wrote:

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For most people adjustments with bass and treble should be enough as they don't know what they are doing. A processor in the wrong hands (the monkey I described above) can do far more damage to the sound with a tool like that than good. Give a paint brush to a kindergartener and all you get is a mess. But that brush in the hands of someone who knows what they are doing gives us the Sistine Chapel.

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Steven Kephart wrote:

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There is a lot more going on there beyond the simple output differences. You are talking about two different subs with different harmonic distortion characteristics and different frequency responses. However with the same sub, try swapping an amplifier with one that produces twice the power and you will be surprised at how small the jump in audible output really is. I know I was when I went from a Soundstream Reference 500 to my Arc 1500dr on my Brahma 10.

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Steven Kephart wrote:

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Actually 10 dB is double the loudness.

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Steven Kephart wrote:

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Actually Dave is highly respected around here because of the extensive research he does and the experience he has. It helps having friends who happen to be engineers at Harman Kardon. You really need to pick your fights more wisely. This forum isn't like many of the others, with teenage kids blabbing their mouths trying to sound like they know something. Many of the people here have extensive backgrounds in this field.

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The decibel is a unit of measurement relative to a specified level. 
3 dB is not twice as loud.
3 dB is approximately double power.
-3 dB is approximately half power.
10 dB is twice as loud. 
-10 dB is half as loud. 
150 dB is twice as loud as 140 dB.
140 dB is twice as loud as 130 dB and so on...

No reason yet for locking this thread tcss, so please try to keep it that way. BTW, Rule # 3, rules created by tcss should be taken with a grain of salt ;)

the12volt • Support the12volt.com

donpisto wrote:

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Turning up the gain IS asking for the amp to do more. In turn, when asking the amp to do more work, it will heat up. Turn up the volume on your HU, it will heat up more. Turn up the bass, it will heat up more. Why? Because it's requiring more out of the amplifier. What you are saying doesn't make sense. It's like saying if you run a lot of programs on your computer, it's not gonna slow it down, but asking it to do more will slow down.

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jmelton86 wrote:

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What amps do you know of that won't accept less than 2v input? I walked outside and checked my sub amps. They accept from 8v - .003v. Meaning, even 3/1000 of a volt will still give the amp enough to reach full power. My front stage amp goes from 5v - .2v. Do you see what we're saying?

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donpisto wrote:

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Steven Kephart wrote:

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Actually 10 dB is double the loudness.

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From what I have seen and heard many people say, including manufacturers is that to acquire a 3dB gain, you would need to double the cone area, or double the power. Here is one link that specifically states that 3 dB is twice the loudness: https://trace.wisc.edu/docs/2004-About-dB/

Speaking to anyone who competes in SPL will also tell you 3 dB will be twice as loud. How do you figure 10 dB?

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tcss]C wrote:

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uple of quick notes before this thread gets locked. 3 db requires twice the power, it is not twice as loud, 10 db is. The definition of a db is " the smallest differance in volume the human ear can detect". So how again can anyone hear .5 db?

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donpisto wrote:

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Oh really? So tell me, I guess I should be able to fine tune my system by adjusting the bass and treble from -7 to +7? That is enough? I think not. It has no EQ that is usefull without the H701 processor. Do you see any SQ guys running the W200 or W205 without the processor? Can you do time alignment and set your soundstage without the processor? The deck, is really useless without the processor if you want the audio to sound right. I'm currently using it without the processor and it sounds okay.... and please don't tell me adjust the bass and treble is because I am not setting it right, you need more than that. You need to set crossover points and adjust the slope on them as well.

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donpisto wrote:

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Again, do a little research and get some experience before you blab your mouth. Having a higher post count doesn't mean you know more ;)

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Steven Kephart wrote:

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Actually Dave is highly respected around here because of the extensive research he does and the experience he has. It helps having friends who happen to be engineers at Harman Kardon. You really need to pick your fights more wisely. This forum isn't like many of the others, with teenage kids blabbing their mouths trying to sound like they know something. Many of the people here have extensive backgrounds in this field.

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tcss]R wrote:

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le #1, don't argue with Hamfist. Rule #2, see rule #1.

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the12volt wrote:

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No reason yet for locking this thread tcss, so please try to keep it that way. BTW, Rule # 3, rules created by tcss should be taken with a grain of salt ;)

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Things are being blown way out of proportion. It seems as though I may be stepping on some toes and playing with fire.

As mentione by 12volt. 3 dB is theoretically doubling the power. That was my intent. I also assumed it would be twice as loud. Here is where I failed and I think even 10 dB being twice as loud may not be appropriate to go by. What humans hear is very subjective. What person A finds to be loud, say on a scale of 1 - 10 (rating loudness of the vehicle at say 9) can be different from Person B, who rates loudness at say 6 on the same scale. Could be many reasons for this. Person B may have heard louder stereos before than Person A, for instance.

I'm sure the frequency at what we hear and feel can be perceived differently as well. What the human ear perceives as loudness is difficult to compare for everyone.  When I stated that 3 dB will be twice as loud, it should have been referenced to the mic, or meter.

Also, my experience of noticing a 0.5 dB difference was done quite some time ago. Another fault to this is more of what I felt rather than heard. I can state that it is highly possible that I highly felt the difference rather than heard.  I will, however, state that 3 dB is noticeable in my experiences. To truly put that to a test, one would need to be listen to the exact same setup, just one having double the power than the other and simply just listen. That means no adjust the volume, just sitting back and listening. I don't know if it is possible to state how much louder one system would be over than the other, but a difference will be noticed.

As for the H701, it isn't the best processor out there, but it is still a good one. I have been using the W200 in my vehicle for a few months now without it and can't really do much without the processor. For a common person that just wants sound, it would be fine, but if you want to set the soundstage, the processor is a must. There several other processors to consider besides the H701, such as the F1 Status processor, the RF 3sixty.1 and .2, PPI has a pretty sweet one and I'm sure I'm leaving others out.

I'm sure I came off rude and jerk-like, making insults and whatnot. I apologize for my childish actions and bickering back and forth doesn't answer the original poster's question. I do believe a better enclosure is recommended since it is currently in I believe 2.5 cubes sealed, and he is looking for more output. Going ported and revising the enclosure specs and tuning frequency will make a huge difference. That sub will also take more than 1.2k, so giving it 2k or a tad more is completely fine. A new enclosure would always be the cheapest route and I would recommend it first as well. If he is still unsatisfied, then giving the sub more power is what I would recommend. However, if 1.2k is reaching near the driver's limitations, then I would not advise more power to the sub.

I hope this clears things up a bit.

donpisto wrote:

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Steven Kephart wrote:

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Why wouldn't you go past 3/4 if the amplifier never clips? I set my gains with an oscilloscope and found I could turn the gains all the way up and never get clipping. What do you think will happen by doing this?

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I don't recommend it, because there are many people who don't know what they are doing...even them turning it up beyond 1/2 gain can damage the amp. But you're right, if you know what you're doing you can run full gain and be fine, however, some people like to turn up bass boost. All the bass boost is, is pretty much an EQ. It boosts a certain frequency dependent upon how much you turn up the bass boost. I personally don't use it and don't think it is really necessary. Just that people who dont know much turn it up, and run full gain, and wonder why their equipment gets damaged.

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Education is part of you giving an answer. let us use your recomendation and your example. I have a 4V output deck and an Amp that will accept .1V to 8V. 1/2 way would kinda works since 4V is 1/2 the scale. But what if the Amp's range is .1V to 4V? Then by your blanket setting you have set the amp up impropperly likely cuasing the amp to clip easily. 

Addressing the Bass Boost: If you encounter someone doing this then explain to them how to properly get more bass. People use the gains to boost the bass because it is easier or a lot cheaper or..... (They use Equalizers / Processors for the same reason.) Clearly this in not what the gains are for nor is it the proper use of an Equalizer/ Processor. If the gains are set up properly and they do not have enough bass then they need to upgrade or buy more "Stuff" (yes that is a techniqual term) otherwise they risk damaging their equipment.

donpisto wrote:

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Steven Kephart wrote:

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Actually 10 dB is double the loudness.

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From what I have seen and heard many people say, including manufacturers is that to acquire a 3dB gain, you would need to double the cone area, or double the power. Here is one link that specifically states that 3 dB is twice the loudness: https://trace.wisc.edu/docs/2004-About-dB/

Speaking to anyone who competes in SPL will also tell you 3 dB will be twice as loud. How do you figure 10 dB?

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I think this has now been covered by both TCSS and THE12VOLT...I like rule #3 Hehehe

donpisto wrote:

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Steven Kephart wrote:

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Actually Dave is highly respected around here because of the extensive research he does and the experience he has. It helps having friends who happen to be engineers at Harman Kardon. You really need to pick your fights more wisely. This forum isn't like many of the others, with teenage kids blabbing their mouths trying to sound like they know something. Many of the people here have extensive backgrounds in this field.

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I'm not trying to pick any fights, but I'm trying to get facts out rather than someone misinforming another person. I dont understand how he states that if an amp "is running hotter", it ISN'T because you turned the gain up, it's because you are asking it to do more. That does not make ANY sense whatsoever. It's contradictory.

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This is thier point to you. You have been making contradictory statements getting your theories a bit mixed up in your explainations and they were correcting what you said. They encourage all to jump in as no one person "knows" everything about this audio world nor can one person have enough time to answer all the questions. A lot of these guys here are real world installers.

I have MAD respect for these guys running around with the yellow symbols under there names. What they are telling you is accurate and well researched. If they don't know they will find out.

A side note;  I have Met Heamphyst in the real world and listened to his system and can tell you he has put theory into practice!

donpisto wrote:

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Thanks tcss. Glad to be here and sorry for offending anyone.

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