need help with new alpine F450 amp

[adlostatsea 10+ year member]

I just installed a new alpine f450 5 channel amp in my tacoma. 4 channels go to stock speakers and 5th to an alpine type R 10, 4 ohm dual voice coil run parrallel down to 2 ohms. The problem is that it cuts out if I turn up the gain any more than 1/4 of the way on the sub. I have disconnected the mids and tested and it still cuts out. I have tested voltage at power input and it never drop below 12v. When it cuts out red light comes on and sound cuts off. I'm running Alpine 9815 head unit. The system is loud with gain down but I should be able to get more out of it. Please help me get what I paid for...

Thanx AD

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[btnhfan 5,000+ posts]

Why are you messing with the gain?

Set it once and be done with it.

 

[adlostatsea 10+ year member]

I'm not messing with the gain. just trying to set it to get the most out of my amp. I should be able to turn it all the way up without it cutting out or at least half way. as it is now I almost have to turn it all the way down to prevent it from cutting out when the bass hits.

 

[btnhfan 5,000+ posts]

No no no

Read the gain setting tutorial.

You dont want the gain all the way up.

The amp is saving itself by turning off.

 

[tbrikner 10+ year member]

My 2 10" subs werent loud enough with my alpine head unit (7923 model) either. Theyre in a sealed downfiring box in my x-cab pickup. I was going to install a line driver to boost voltage, but finally another installer asked what volume are you listening on that alpine? I said 16 at the most. He said you should be listening at the loudest at around 30 on alpines (they go up to 35), and turn the gains way down. What a world of difference! Ive turned the gains up a little maybe 1/4 but no more on both the sub amp (memphis mc500) and component amp (jbl 90x2). No line driver needed. The difference in bass is huge, much louder.

Are you sure though that the Alpine is OK with 2-ohm load on the sub channel? Not familiar with that amp, but make sure. Hope this helps.

 

[btnhfan 5,000+ posts]

1. That installer is full of sh!t. Set the gains correctly at whatever volume you ordinarily listen to.

2. I have no idea if its okay with a 2 ohm load. Check the owners manual or alpines website. They have the manuals there.

 

[adlostatsea 10+ year member]

well I looked up how to set gain and as soon as I get time will be correctly setting it. for the most part I did what they said I just didn't use the 45hz tone. I think the way it is set up now is about what it will be after I set the new setting, without the ocassional cut out on some songs. I just did't understand the technical side of the gain setting and what it actually does. Thanks for all the help and not letting me spend a bunch of money on crap that won't make any difference, not to mention frying my amp.

AD