Questions about my headunit and amp

[gonzala 1]

Hey guys, I've received good information in my other topic so I thought I'd come back for some more. Got some questions to do with the setting on my sub amp and head unit

Currently I'm running a infinity reference 611a amp powering 2 infinity 1050w subs but I'm looking to move up to a single 15". my head unit is a pioneer deh-p80mp and I play all my music off my multi-media player via aux input but the devices output is really quiet so with the way my setup currently is, the maximum I put my head unit to is 55 out of 60. I thought that head units have a point at which they clip but I can't hear any distortion. So I don't know if this is a problem or not.

The way the sub amp is setup right now sounds decent but I think the settings are kind of weird, like the low pass frequency looks high, I don't know why there is a high pass frequency but I think its the bass boost frequency and the bass boost is turned up to the max. From what I've read this doesn't seem all to right but I'm not sure any ideas?

Also I have an oscilloscope at my school which I could use to set the gain I hope, but when I go to set the gain should I play the 50 hz tone through my media-player or off a test cd even though I will play just about all my music from my media-player? I also worry about the head units volume needing to be to so high because I've read people set their gain so that their max volume is at about 3/4 of the head units.

The low pass frequency is set at the top a little to the right maybe sitting around 150 hz and as I said before the boost is at the max with the hp frequency at the top a little to the left at around 30 hz

[KU40 173]

turn that boost all the way to the left. Pronto. LF frequency should only be 1/4 of the way up. High pass frequency shouldn't even be on there unless that is for pass-thru RCAs to hook up another amp to?

[gonzala 1]

yes there is a set of rca outputs so you can daisy chain amps on there they just didn't make it into the picture. I still don't see why there would be a hp frequency, the amp should let the rca signal pass through clean. It looks more like a bass boost frequency setting. When I look the amp up on crutchfield it says the DBO has an adjustable frequency of 20-80.

[///M5 2,833]

20 is almost an all pass. For your ears, it is.

[gonzala 1]

20 is almost an all pass. For your ears, it is.

Gotta say I was kinda excited to see M5 post in my topic, thought I was either going to get awesome info or criticized for something I'd done. I'm just confused though heh. What do you mean by 20 is an all pass?

[///M5 2,833]

You can't hear below 20Hz so if you filter out all those frequencies it will pass everything audible. IE it will make no difference and is just like having a loop for the cables to go through.

[gonzala 1]

it shouldn't have a hp frequency setting for the rca outputs because it only ever gets a bass input. unless of course it were intercepting the signal for the rear speakers and then passing the signal on over to the 4 channel amp with the low frequencies already cut out.

[///M5 2,833]

High pass frequency shouldn't even be on there unless that is for pass-thru RCAs to hook up another amp to?

You can't hear below 20Hz so if you filter out all those frequencies it will pass everything audible. IE it will make no difference and is just like having a loop for the cables to go through.

it shouldn't have a hp frequency setting for the rca outputs because it only ever gets a bass input. unless of course it were intercepting the signal for the rear speakers and then passing the signal on over to the 4 channel amp with the low frequencies already cut out.

So you won't be using it. Not knowing where it is in the signal path, just set it to the 20Hz end and it won't matter what it does

[gonzala 1]

sounds good, thanks. Just need to know what I should do about setting my gain now.

[gonzala 1]

anybody?

[KU40 173]

There is a gain setting tutorial on this site, in this amplifier section in fact.

If you don't want to do all that and just want the simple way of how I do it, turn the head unit up to as loud as you'd listen to it, then slowly turn the amp gain up from the lowest setting until the subs stop getting louder, start making funny noises, or stop moving out as much. Normally it's the funny noises that you'll hear. But step back a few feet when you listen (with the trunk open), as it's easier to hear distortion from a bit of a distance.

[gonzala 1]

Thanks for the suggestion but as I stated in the original post I want to try to use the oscilloscope at my school. My question is should I use my media player to play the tone through the aux input when testing? Even though the media player is on the quiet side. Keeping in mind that I will play all my music off of it.

[KU40 173]

If you use the media player to play all of your music, then yes, use that to set the gain.

[gonzala 1]

ok thanks