* General Rule*- Subsonic Filter set to 1/2 Octave below Recommended Box Tuning HZ? Confused...

[PeckawoodJones]

Just to clarify...

 

The general "Rule of Thumb" is to set the amps Subsonic Filter to 1/2 Octave below Recommended BOX Tuning HZ? 

 

So for example, I have 2x Skar 12" ZVX12V2's in a Skar AR2X12V Dual 12" ported enclosure on a Skar SKv2-3500.1D amp.

 

The Box's tuning frequency per their website is 33hz.

 

So I would tune the subsonic filter to around 33hz - 1/2 Octave, being 24.75hz, correct? 

 

 

 

 

[Joe X]

That's correct but bear in mind that it is just a rule of thumb and it may not be adequate in a number of circumstances, for example:

 

1) you are applying a lot of power.

2) suspension characteristics of the sub.

3) box volume / port area.

4) your actual tuning is not what you think.

5 ) audio processors specially if improperly set.

6) many others.

 

A better way to get your SS frequency is measuring your actual tuning of the box you built and software modeling checking the excursion plot and making sure your excursion stays below Xmax.

 

 

[PeckawoodJones]

Understood Joe and thank you for the response it's much appreciated.

 

Box tuning is 33hz, I've used the DD-1 to tune the amp however I know this obviously doesn't cover everything as you mentioned. 

 

Additionally, in one of the videos of Steve I watched recently he was going over the importance of why you need a quality LOC, which I'm using an AudioControl LC2iPro, which I tapped some speaker outputs as my inputs into the LOC.  Steve mentioned that I believe (I could have manterrupted) that most amps "like" 5volts in from a LOC. I used a multi-meter to adjust gain on the LOC and was able to get 5volts finally right on the mark.  Did I understand this correctly? 

Thanks again for any help in advance. 

Edited September 21, 2023 by PeckawoodJones

[Joe X]

Ok, you should find your maximum clean signal volume of your head unit with the DD-1,  at the RCA output of the LOC you should make sure that the "maximized" light is not blinking, should be completely off, the output voltage of the LOC should never be set above the input voltage of the amp, I guess I will agree that 5V Rms that you measure with the multimeter should be fine, Then you use the DD-1 connected to the amp output and set the amp gain making sure the DD-1 shows no clipping.

 

If you use bass restoration available on the LOC test engaging in it during the gain setting procedure, making sure no clipping ocurrs.