TOPIC:

Hi all.

I'm a very happy SHD user but I am confused at the volume level in relation to SPL.
I am a Room EQ Wizard user and am aligning my subs to my mains which I have no problem with except when it comes to SPL.
Yesterday, I level matched my mains and my subs at 75db using a calibrated UMIK1 and the volume dial was set to -20db on the SHD.
I saved everything I did within the SHD the loaded the saved file back in to the SHD to ensure it is "locked in".

Today, I have set everything back up to make some minor changes to the subs and have carried out another level matching exercise to be sure I am doing things right.
The 75db SPL point has now moved from being -20 on the display to -38! That's nearly a 20db change!

I now have to go through the entire level matching procedure again and I am now left wondering if the 75db point will keep changing every time I turn the SHD on!

Can anyone shed any light on this at all?

Cheers,

Mike.

The main issue here is that if I level match my subs to 75db at -20 on the SHD display and the 75db point changes within the SHD, my subs will no longer be level matched with my mains and that would be a disaster.

Does the SHD have a set 75db point at all @devteam

Are you sure that on both occasions the dB setting in REW was the same. I ask because I’ve made the mistake of not noting the REW level myself in the past. 

Hi.

The volume level in REW always sets itself to -12DBFS as I chose within the settings.
I also make sure that REW cannot control the input volume so I untick that box within preferences.

It has done this before in the past.

Its really unusual?

I have adjusted my settings and level matched to suit the new -38 volume level.

I just hope it stays at this level as it will be a nightmare if it changes again!

The SHD control is a gain control. The dB SPL will not change unless your following amplifier gain changes. Power off and on does not change any SHD gain. There is some other part of your system with varying gain confusing you perhaps.

Hi.

I'm using Genelec 8341A speakers which are powered.
It must be those that are causing the issue because it has happened at least twice now.
It has only happened though when I've been running a new speaker/sub calibration due to a change of speaker position or something along those lines.

I level match and run EQ via the GLM (Genelec Loudspeaker Manager) software first then run REW afterwards.

Gotta be the Genelecs! The SHD is faultless in operation and, in my opinion, it beats the Anthem STR Preamp I had before it by quite some margin.
Especially when you consider the price difference! 

@ Exponential

This is an odd one indeed.. It sounds like something is changing the level somehow in the setup. You'd hear the 18dB level difference. It should be quite obvious with another source than REW to remove the potential measurement artifact of REW sweep level/UMIK-1 level inside OS? 

As correctly explained by the valuable posters, SPL won't change inside the SHD. It's always the same unless you are modifying some of the output levels inside the DSP (e..g output faders?)

Keep us updated on how things go. 

DevTeam