Freq and DBO setting

[Fiorenini 10+ year member]

I just finished pulling the old wire and running new 14g in my car, it is a 2003 Z4. I have everything connected and powered up but have a question before I can properly set the amp, I am not entirely sure how to set the DBO and Frequency? I was planning to set the DBO at 25ish since that’s 10 below box freq but before I start playing around I want some input.

I attached a screenshot of the section of amp in case anyone needed it for reference.


This is what I have installed now.

Pioneer MVH-S512BS
Infinity Kappa K5 5 channel amp
Polk 6502 components———kick panel and 1” in door pillar/ Channels 1-2
Polk DB652 6.5"———————behind seats/Channels 3-4
Polk DB402—————————- in doors/run off of HU
Punch P2 P2D4-12——————in trunk/Channel 5 Freq. 27-250hz

Ported box is tuned to 34hz and the sub

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[02WS6]

I just finished pulling the old wire and running new 14g in my car, it is a 2003 Z4. I have everything connected and powered up but have a question before I can properly set the amp, I am not entirely sure how to set the DBO and Frequency? I was planning to set the DBO at 25ish since that’s 10 below box freq but before I start playing around I want some input.

I attached a screenshot of the section of amp in case anyone needed it for reference.


This is what I have installed now.

Pioneer MVH-S512BS
Infinity Kappa K5 5 channel amp
Polk 6502 components———kick panel and 1” in door pillar/ Channels 1-2
Polk DB652 6.5"———————behind seats/Channels 3-4
Polk DB402—————————- in doors/run off of HU
Punch P2 P2D4-12——————in trunk/Channel 5 Freq. 27-250hz

Ported box is tuned to 34hz and the sub

I believe DBO is a variable Sub-Sonic - You're right in the ballpark IMO - Set within 10hz below ported box tune for ported. Set to 35-40hz for sealed box.

 

[Fiorenini 10+ year member]

I believe DBO is a variable Sub-Sonic - You're right in the ballpark IMO - Set within 10hz below ported box tune for ported. Set to 35-40hz for sealed box.

thanks for the repl,

I think that I will stick to the 25-30 range basically because I have no way of putting it exactly on 25 by eying it, i will set frequency between 60-80 but I will play around to see which works best. i would normally leave the boost alone and zero it but wonder if it’s needed at all since I am setting the DBO?

 

[02WS6]

thanks for the repl,

I think that I will stick to the 25-30 range basically because I have no way of putting it exactly on 25 by eying it, i will set frequency between 60-80 but I will play around to see which works best. i would normally leave the boost alone and zero it but wonder if it’s needed at all since I am setting the DBO?

Depends on how you set your Amp gain. If you're properly setting via Tweeter, oscope or Multimeter then I'd leave it at zero and EQ from your deck. If for some reason you want/need boost or use a remote boost knob then lower gain and compensate using the boost. Just make sure you're not clipping the output which will kill your sub.

 

[Fiorenini 10+ year member]

Depends on how you set your Amp gain. If you're properly setting via Tweeter, oscope or Multimeter then I'd leave it at zero and EQ from your deck. If for some reason you want/need boost or use a remote boost knob then lower gain and compensate using the boost. Just make sure you're not clipping the output which will kill your sub.

I don't have a way to test properly, so I am winging it. I will leave the boost alone because I don’t think I will need it.

I do have another question, when setting the amp I thought the sub input should be set to EXT since I do have a sub input on my head unit, but setting to EXT does not work, I do get bass when i switch to INT, does that mean I have done something wrong?

 

[fithwheel]

I do have another question, when setting the amp I thought the sub input should be set to EXT since I do have a sub input on my head unit, but setting to EXT does not work, I do get bass when i switch to INT, does that mean I have done something wrong?

That sums the signal from one of the other channels on the amp to the sub channel when the switch is set to int. That’s what you would use if you didn’t have a sub out on your hu. So it will work like that but you won’t have control of the sub from the hu.
Sounds like you’re not getting signal from the sub out on the hu to the amp. I’m not at all familiar with your hu but there maybe a sub on/off in your hu settings. If so make sure it’s set to on. Also sub level is set to 0 from factory so turn that all the way up if you already haven’t.

 

[Fiorenini 10+ year member]

That did it, my head unit had my sub switched off.

I am trying to tune my amp but trying to set my amp and head unit is a pain, any recommendations on how to set amp and/or head unit xovers?