MiniDSP Flex HTx

[Mort]

If you are running REW in your connected PC or Mac over USB to the HTx, you need to keep in mind that the USB interface flips the LFE and Center Channel relative to an HDMI interface.

First I've read that. So when I mute my center on the console, it will actually mute LFE?

You also need to configure your PC/Mac sound output for 5.1 channels.

Ah. And then REW can send an LFE?

Is the 10db hot LFE a standard or a mistake? Or both?

 

[danstahl]

Standard: https://en.wikipedia.org/wiki/Low-frequency_effects

 

[thcdru2k]

If you’re keeping a discrete 5.1, the proper way to measure the sub in REW is to sweep the LFE channel directly with the PC set to 5.1 and routed to the sub output, then verify that the sub measures about 10 dB higher than the mains since LFE is encoded 10 dB low and restored in playback. When bass management is active, ensure the HTx LFE mix level is set to minus 10 dB so redirected speaker bass sums correctly with the LFE channel. Alternatively, you can simplify the gain structure by running the AVR as 5.0 and folding LFE into L and R upstream, letting the HTx manage all low frequency routing from full range channels, in which case you just sweep L or R in REW to evaluate the managed bass path and avoid maintaining a separate LFE level altogether.

 

[Mort]

If you’re keeping a discrete 5.1, the proper way to measure the sub in REW is to sweep the LFE channel directly with the PC set to 5.1 and routed to the sub output, then verify that the sub measures about 10 dB higher than the mains since LFE is encoded 10 dB low and restored in playback. When bass management is active, ensure the HTx LFE mix level is set to minus 10 dB so redirected speaker bass sums correctly with the LFE channel.

That's helpful, as have been other suggestions. I have been doing it incorrectly.

Alternatively, you can simplify the gain structure by running the AVR as 5.0 and folding LFE into L and R upstream, letting the HTx manage all low frequency routing from full range channels, in which case you just sweep L or R in REW to evaluate the managed bass path and avoid maintaining a separate LFE level altogether.

Matrix or channel mixer is better for this? The one before Dirac, I assume? I think this is my mistake, I was doing it after in the matrix.

 

[thcdru2k]

That's helpful, as have been other suggestions. I have been doing it incorrectly.

Matrix or channel mixer is better for this? The one before Dirac, I assume? I think this is my mistake, I was doing it after in the matrix.

Correct. Channel Routing defines what each speaker is before Dirac. Matrix Mixer decides where each corrected speaker signal goes after Dirac. I don't think what you did before would be audibly wrong though. I think it just means if you did the fold or mix after, it might be outside of Dirac correction.

 

[Matt S]

I own an htx and I reduce by 10db. I don't think that there is a different way to work it

I think you can. I just took the easier route.

You could bring those channels up by 10db and then, using REW to bring your sub up another 10db using its gain. Should be no reason why that wouldn't work, if, using REW, you measure the left right vs the sub with low frequency white noise.

I might try it and let you know..

 

[danstahl]

I think you can. I just took the easier route.

You could bring those channels up by 10db and then, using REW to bring your sub up another 10db using its gain. Should be no reason why that wouldn't work, if, using REW, you measure the left right vs the sub with low frequency white noise.

I might try it and let you know..

That's going to clip at high volume.

 

[Matt S]

That's going to clip at high volume.

Considered. Running it all a few db down though.... should be okay. Cant get to high volume with neighbours also.

 

[Matt S]

Any HTx owners experienced digital noise under similar circumstances?

I was flicking back and forth between Plex and Apple Music when suddenly, from Plex, I was listening to digital noise from the surround channels. It was all very odd and has happened a few times since I have had the HTx. Power cycling and a reboot restores correct operation, but strange nonetheless.

 

[thcdru2k]

Any HTx owners experienced digital noise under similar circumstances?

I was flicking back and forth between Plex and Apple Music when suddenly, from Plex, I was listening to digital noise from the surround channels. It was all very odd and has happened a few times since I have had the HTx. Power cycling and a reboot restores correct operation, but strange nonetheless.

I may have run into something similar once. I can't remember whether I was switching sample rates on my WiiM (via Toslink) or switching inputs between Toslink and analog (audio coming from my AVR pre-outs).

The Flex HTx runs its DSP internally at 48 kHz, so it has to lock onto the incoming clock and resample. If this is done rapidly I think it can lose sync, which results in noise. Power-cycling the Flex HTx resolved it.

I haven’t been able to reproduce it consistently but I also haven't really messed with my WiiM sampling rates I just keep it at 48 kHz.

 

[Mort]

Yes, brief crackles happen from time to time when changing apple tv channels. Usually it's the rear channels.

 

[Matt S]

This is continued noise from the rears, playing the song, until I reset the unit.

All good after reset, and normally a lot of switching back and forth to get to that stage, but ...

 

[Mort]

This is continued noise from the rears, playing the song, until I reset the unit.

All good after reset, and normally a lot of switching back and forth to get to that stage, but ...

Ah no, have not had that.