Alpine ut-73bt controls for Subwoofer?

[gduncanson]

The 73bt has dedicated rca outputs for a sub and a setting under Audio for enabling the SUB. I've installed a KTP-445A amp inline to boost the radio's amp for it's front and rear speaker output. The SUB is an Infinity Bass link II connected to the RCA sub outputs. I've tinkered with a few settings and I'm either not getting much a bass boost or too much across all the speakers.

The 73bt has a LPF and HPF with options for 80Hz, 100Hz, 120Hz. Then it has a SUB level boost (0<15) and a phase switch. And It also has a Base Engine SQ setting (1<5). This last setting makes a dramatic if heavy handed change.

The SUB has a crossover too that tops out at 120Hz, The rest of the car is a 2012 Jetta wagon with factory speakers (3way components in front doors and 2way components in the rear doors). The plan is to replace them too eventually.

So Questions for anyone familiar. 1-If I set the HPF and LPF on the Alpine; shouldn't that prevent the door speakers from having to handle the low end and send just the low end to the SUB? 2-Should I use the Bass engine SQ or use the gain settings on the Alpine/Sub? Any tips would be appreciated.

Click to read more...

 

[2023 LTZ]

Hpf and lpf will do exactly as you said. They guide the tolerable frequencies to your speakers. The sub rca only allows bass frequencies and the infinity then has its lpf. I’d look into it’s stated frequency capability and set lpf accordingly. Typically ppl allow subs to go up to 80,90 or 100hz. The crossover integrates the frequencies to an ideal merger.

 

[Bobbytwonames 5,000+ posts]

The 73bt has dedicated rca outputs for a sub and a setting under Audio for enabling the SUB. I've installed a KTP-445A amp inline to boost the radio's amp for it's front and rear speaker output. The SUB is an Infinity Bass link II connected to the RCA sub outputs. I've tinkered with a few settings and I'm either not getting much a bass boost or too much across all the speakers.

The 73bt has a LPF and HPF with options for 80Hz, 100Hz, 120Hz. Then it has a SUB level boost (0<15) and a phase switch. And It also has a Base Engine SQ setting (1<5). This last setting makes a dramatic if heavy handed change.

The SUB has a crossover too that tops out at 120Hz, The rest of the car is a 2012 Jetta wagon with factory speakers (3way components in front doors and 2way components in the rear doors). The plan is to replace them too eventually.

So Questions for anyone familiar. 1-If I set the HPF and LPF on the Alpine; shouldn't that prevent the door speakers from having to handle the low end and send just the low end to the SUB? 2-Should I use the Bass engine SQ or use the gain settings on the Alpine/Sub? Any tips would be appreciated.

I would try sub level at max and crossover at 80 hz.

 

[gduncanson]

I'll give that try, setting the LPF on the head unit sub outputs to 80Hz and leaving the HPF at 120Hz. If I didn't set an HPF, what would the radio do when the subwoofer is enabled in the menu? would it select a better HPF for me?

The subwoofer specs:
Variable Electronic Crossover: (32 Hz - 320 Hz)
Variable Bass EQ: +3 / -6 dB @ 45 Hz
Frequency Response: 20 - 120 Hz