Fosi v3 sub integration using REW + Crown XLS 1502

[HighFutility]

I posted on the fosi v3 review as I'm sure others have this question as well. https://www.audiosciencereview.com/...-audio-v3-amplifier-review.45757/post-2554094


Looking for a bit of help with a Fosi v3 set up.

My current setup is computer> fosi v3 > Mechano-23 (https://www.audiosciencereview.com/...ers-h-v-off-axis-measurements-included.41757/).

I am using peace APO as an equalizer.

I have a crown xls 1502x sitting around and I thought, hey why don't I hook up a sucker to this bad boy. This is the dilemma, the pre-out is full range, the volume pot does not control the sub out volume. The crown xls1502 has a high pass filter option so that should help me on one front. How do I go about integrating the sub woofer with the Speakers?

My initial thought process was to unplug the speakers use REW sub cal (30-80hz) to get the sub running to 75db or maybe a few db higher or 80db. Who doesn't love bass? What is the general rule of thumb with sub woofer integration anyways?

GREEN = NO EQ @ 75 DB 1-20 KHZ Speakers (75 Db using speaker cal)
BLUE = SUB CAL(30-80)HZ @ 75DB. Test ran at 1-500hz (pre out sends full range signal)
Brown = CAL(30-80)HZ @ 75DB. Test ran at 1-500hz (used LPF on 1502XLS @ 200hz) test. Works!

Psychoacoustic smoothing

This is the original speaker set up in green @ 75db
as well as the sub set to 75db with a LPF @ 200hz . 200 hz wasn't chosen, was the default so I ran with that. Seemed to full the dip in the room but not sure that is desirable.

When I was not using the pre-out I was using peace APO to EQ the speakers. Now that I am using the Fosi preout How do I go about eq the sub woofer without blowing up my speakers? Is there a way to eq the pre-out signal path only? Or whatever I send to peace APO will eq both the speakers and the pre out sub? Which is what im leaning towards. I guess I can safely apply the speaker eq again and change the LPF to a lower setting on the xls to prevent boosting the overall frequency? There is also a band pass function. As far as I know I cannot set up individual LPF,HPF at the same time. I need to pick one or the other.

Is the only way to solve this is to set the HPF to the lowest setting on the xls, apply peace apo eq and then slowly increase HPF on the xls as well as the gain nob to sort of eq the sub independently. Im just worried the EQ signal will get passed to the pre out and cause issues in the crown or blow it up or something.

Alternative is throw in a minidsip between the xls and fosi pre out, but I wanted to keep this cheap and cheerful

EQ im using is FF from https://www.spinorama.org/speakers/XMechanik Mechano23 DIY/ASR/index_asr.html




TIA

 

[Keith_W]

I have a crown xls 1502x sitting around and I thought, hey why don't I hook up a sucker to this bad boy. This is the dilemma, the pre-out is full range, the volume pot does not control the sub out volume. The crown xls1502 has a high pass filter option so that should help me on one front. How do I go about integrating the sub woofer with the Speakers?

You have two options.

Option 1: Configure your system like this:
PC --> Fosi V3 --> Speakers (via speaker output) and Crown XLS1502 (via preamp output).

As you mention, the pre-outs on your Fosi are fixed at max volume. This means that you can not use the volume control on your Fosi V3. Instead, control the volume on your PC. The Crown XLS1502 should have its own volume control. Adjust the volume of your sub so that it blends with the speaker (use measurements) and leave the volume controls alone after that.

The disadvantage of this solution is that you can not control your sub independently of your speakers with DSP (i.e. no independent time and phase alignment), you can apply "universal" DSP only. The Crown XLS1502 should have some limited DSP functionality - its similar in class to my Yamaha pro audio amps.

Option 2: Buy a 4ch DAC and reconfigure your system like this:

PC --> 4ch DAC (channels 1, 2) --> Fosi V3 --> Speakers
PC --> 4ch DAC (channel 3) --> Crown XLS1502 --> Sub

Volume control will now be done with your PC or your 4ch DAC if it has this capability. Suitable candidates include RME Babyface, Focusrite 4i4, etc. Or you could consider something like a MiniDSP 2x4HD, but it does not have a volume control dial. You will need the optional remote for volume control.

My initial thought process was to unplug the speakers use REW sub cal (30-80hz) to get the sub running to 75db or maybe a few db higher or 80db. Who doesn't love bass? What is the general rule of thumb with sub woofer integration anyways?

There is no "general rule of thumb" for subwoofer integration, that's a whole book worth of information in that question. Or if not a book, a very lengthy article.

Re, your graphs: I didn't bother looking at them. If you want us to look at your measurements, post the MDAT. You will have to zip it first.

 

[HighFutility]

You have two options.

Option 1: Configure your system like this:
PC --> Fosi V3 --> Speakers (via speaker output) and Crown XLS1502 (via preamp output).

As you mention, the pre-outs on your Fosi are fixed at max volume. This means that you can not use the volume control on your Fosi V3. Instead, control the volume on your PC. The Crown XLS1502 should have its own volume control. Adjust the volume of your sub so that it blends with the speaker (use measurements) and leave the volume controls alone after that.

The disadvantage of this solution is that you can not control your sub independently of your speakers with DSP (i.e. no independent time and phase alignment), you can apply "universal" DSP only. The Crown XLS1502 should have some limited DSP functionality - its similar in class to my Yamaha pro audio amps.

Option 2: Buy a 4ch DAC and reconfigure your system like this:

PC --> 4ch DAC (channels 1, 2) --> Fosi V3 --> Speakers
PC --> 4ch DAC (channel 3) --> Crown XLS1502 --> Sub

Volume control will now be done with your PC or your 4ch DAC if it has this capability. Suitable candidates include RME Babyface, Focusrite 4i4, etc. Or you could consider something like a MiniDSP 2x4HD, but it does not have a volume control dial. You will need the optional remote for volume control.



There is no "general rule of thumb" for subwoofer integration, that's a whole book worth of information in that question. Or if not a book, a very lengthy article.

Re, your graphs: I didn't bother looking at them. If you want us to look at your measurements, post the MDAT. You will have to zip it first.

Hey thanks for the response. I do own a mini dsp, so I guess I could give that a whirl. I'm still relatively new to REW and EQ in general. I will tinker a bit when I have some time and repost with MDAT files.