I need help adjusting my Alpine MRV-F300

[ridinhigh]

I have:

Kenwood Excelon x998 head unit

Polk Audio db651s speakers (4)

Alpine MRV-F300

I heard that head units start clipping at about 3/4 volume, that would be 26.25 (we'll say 26) for me. I want to know if I set my radio to volume 26 and turn the gain up (with all filters off) until something doesn't sound right, then back it down, is the gain set right?

I also heard that you should leave headroom. Example: If you turn your radio volume all the way up and then set the gains, you have to turn the radio all the way up to get it loud. If that is the case, why should I set my radio volume to 26 if thats the max volume before it starts clipping? There wouldn't be any headroom. The speakers sound fine with the amp gain at the line to the left of nominal and the HP filter on, but when I turn the filter off and play a bass heavy song it distorts (I forget at what volume, but not all the way up) So should I just turn the filters off and turn the radio volume to 26, set the gains, then turn the filter on and then turn the radio up as much as I want, even all the way? (it sounds good then, good volume at the lower, lowest, and the highest volumes, and doesn't distort)

I dont have any way of getting an oscilloscope.

I plan on turning the HP filter on at around 12 O' clock on the amp, I think it was around 80hz.

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[CSCStang]

I have:
Kenwood Excelon x998 head unit

Polk Audio db651s speakers (4)

Alpine MRV-F300

I heard that head units start clipping at about 3/4 volume, that would be 26.25 (we'll say 26) for me. I want to know if I set my radio to volume 26 and turn the gain up (with all filters off) until something doesn't sound right, then back it down, is the gain set right?

I also heard that you should leave headroom. Example: If you turn your radio volume all the way up and then set the gains, you have to turn the radio all the way up to get it loud. If that is the case, why should I set my radio volume to 26 if thats the max volume before it starts clipping? There wouldn't be any headroom. The speakers sound fine with the amp gain at the line to the left of nominal and the HP filter on, but when I turn the filter off and play a bass heavy song it distorts (I forget at what volume, but not all the way up) So should I just turn the filters off and turn the radio volume to 26, set the gains, then turn the filter on and then turn the radio up as much as I want, even all the way? (it sounds good then, good volume at the lower, lowest, and the highest volumes, and doesn't distort)

I dont have any way of getting an oscilloscope.

I plan on turning the HP filter on at around 12 O' clock on the amp, I think it was around 80hz.

Get a dmm to set the gains...15.00. Yes you can turn the Hu to 3/4 and turn up the gain to distortion then drop back, but you should set it with a multimeter imo. Headroom is having more rms (clean) than the rating of the speaker. Hpf is good at 80.

 

[ridinhigh]

After I drop the gain back can I turn the volume up more or all the way with the Hpf on? I don't really know how to use a dmm, my dad might because he's a mechanic. I haven't noticed any weird sound coming from my speakers with the radio all the way up and the gain low. Do all head units clip, most of them, or only some of them?

 

[CSCStang]

No you don't want to turn it up higher after. Go to the12volt.com and look up setting gains with a dmm. It's pretty easy. There are some hu's that you can go full tilt...80prs, 147,148,149bt are a few.

 

[keep_hope_alive Premium Member]

your head unit has 4V outputs. you can simply set the amp gain at the corresponding 4V gain setting. if that's loud enough for you, then you're good to go. that head unit should have a clean output at full volume, assuming you don't have EQ boosts in your settings.

what version F300? There have been several since the 90's. pic? regardless, they all are designed for 4V inputs, and that setting is close to MIN.

it's not that simple for everyone, which is why the adjustment is there. since the head unit doesn't reach it's rated output until it's at full volume, sometimes you set the gain for a lower hu volume setting. how low depends on several factors, one major factor is if the person is running speakers on the head unit. since you are a fully amplified system, you have the ability to use full volume on the HU.

the reason for "headroom" is to account for newer vs older recordings. if you listen to Eric Clapton recordings from the 70's you'll notice they are quieter than, say, modern rock music.

 

[ridinhigh]

I dont think anybody understands what I'm trying to say. If my head unit can go to 26 before it starts clipping and I set the gains there, I dont have any more volume or "headroom" I can go up to if a lower recorded song comes on, correct? If that's the case why shouldn't I set my gains on volume 17 or 2/4 volume of 35. So does my head unit clip at 26 or no, and can I go full volume safely?

 

[ridinhigh]

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[ridinhigh]

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[LosIsATool 5,000+ posts]

I dont think anybody understands what I'm trying to say. If my head unit can go to 26 before it starts clipping and I set the gains there, I dont have any more volume or "headroom" I can go up to if a lower recorded song comes on, correct? If that's the case why shouldn't I set my gains on volume 17 or 2/4 volume of 35. So does my head unit clip at 26 or no, and can I go full volume safely?

If you set it to low you are getting nothing for preout voltage. Your headroom is volume 26 in this case. If you find yourself using full volume all the time and it's not loud enough that's when you add power if needed or better install, equipment ect

 

[ridinhigh]

The speakers I have are the best speakers I can fit in my truck without going to components. So turn my volume to 26, set the gains, and don't turn the radio up over 26? Then if I want to apply any filters do so, but do I leave the gains where I set them without the filter on or do I turn the gain up more as long as it sounds fine with the filter on? Also, where does my head unit clip? Somebody above said mine shouldn't clip all the way up, others say don't go over 26, which is it? Any recommendations for songs to play while setting the gain? What line should my gain knob be turned to about, the one closest to nominal in the picture above?

 

[ridinhigh]

I forgot somebody above said dont turn the gain up more with the filter on after you set it with the filter off, so ignore that part.

 

[LosIsATool 5,000+ posts]

The speakers I have are the best speakers I can fit in my truck without going to components. So turn my volume to 26, set the gains, and don't turn the radio up over 26? Then if I want to apply any filters do so, but do I leave the gains where I set them without the filter on or do I turn the gain up more as long as it sounds fine with the filter on? Also, where does my head unit clip? Somebody above said mine shouldn't clip all the way up, others say don't go over 26, which is it? Any recommendations for songs to play while setting the gain? What line should my gain knob be turned to about, the one closest to nominal in the picture above?

Why do you say those speakers are the best you can fit? You need a o scope or SMD DD-1 to see when your HU clips.

 

[ridinhigh]

I measured, I can't have any speakers with more than 2 1/8 top mount depth, and the tweeter has to be relatively low profile. It was either the speakers I have or 100 watt rms kickers but I thought the polks would sound better from the reviews and other things. Does anybody here have a Kenwood x998 that can tell me what volume it starts clipping at?

 

[ridinhigh]

your head unit has 4V outputs. you can simply set the amp gain at the corresponding 4V gain setting. if that's loud enough for you, then you're good to go. that head unit should have a clean output at full volume, assuming you don't have EQ boosts in your settings.
what version F300? There have been several since the 90's. pic? regardless, they all are designed for 4V inputs, and that setting is close to MIN.

it's not that simple for everyone, which is why the adjustment is there. since the head unit doesn't reach it's rated output until it's at full volume, sometimes you set the gain for a lower hu volume setting. how low depends on several factors, one major factor is if the person is running speakers on the head unit. since you are a fully amplified system, you have the ability to use full volume on the HU.

the reason for "headroom" is to account for newer vs older recordings. if you listen to Eric Clapton recordings from the 70's you'll notice they are quieter than, say, modern rock music.

What EQ boosts are you talking about? Which position on the gain knob is 4v, or which line?

 

[LosIsATool 5,000+ posts]

He's talking about loudness and bumping up the EQ. This you should not do