Podcast HomeTheaterUnited Podcast Episode 15 - Dave Upton on room correction and calibration with REW and Audyssey (1 Viewer)

[JohnRice]

Yeah, I use my HTPC to run REW and other calibration software.

You are correct that you'll need the MIniDSP 2x4 HD. This is the specific video guide that walks you through the process of sub EQ - it's very comprehensive:

Thanks again Dave. This also might be a step into a better/more up to date method for playing HD audio. Now that Oppo has gone away and their app no longer functions, I've lost my method of controlling playback. So, a Mac Mini might find a permanent home in the HT.

 

[Dave Upton]

Thanks again Dave. This also might be a step into a better/more up to date method for playing HD audio. Now that Oppo has gone away and their app no longer functions, I've lost my method of controlling playback. So, a Mac Mini might find a permanent home in the HT.

You should look into Roon in that case. It’s a game changer for enjoying audio

 

[DaveF]

Good episode. I'm reasonably smart (but no expert) on Audyssey, having read up on it the past couple years. There's a detailed and indexed thread on AVS that discusses Audyssey in depth, that I've spent time on.

I hadn't heard the tips that Dave gave about Audyssey getting tripped up by bass room modes, and working around that with pre/post bass volume changes. Similarly, I've not played with bass timing settings after calibration. I'll give those a look next time I run audyssey. (I do it way too much, because I'm chasing after / working around some futzy subwoofer issues.)

Dave said out loud what I've been thinking but don't readily find said explicitly online: Audyssey is coasting on their brand name, having abandoned new engineering upwards of a decade ago.

This might have convinced me to go for Anthem and ARC when I upgrade pre-pro.

 

[Sam Posten]

I referenced a few different resources in the show. Here they are:

Show notes:
Youtube videos showing room setup, REW, calibration: https://www.youtube.com/channel/UCwxr5jJUgORcMS9FmIaH1jQ/videos?

OK, this is exactly what I lamented in the episode. This is a list of 100+ hours of videos that doesn't give a concise 30 minute "Here is how you set up REW, THIS is what it's going to do for you, and this is how you evaluate the feedback".

If there is a specific episode in that playlist that does those 3 things, please point me to it. Other than that it's more hunting and pecking.

 

[Dave Upton]

OK, this is exactly what I lamented in the episode. This is a list of 100+ hours of videos that doesn't give a concise 30 minute "Here is how you set up REW, THIS is what it's going to do for you, and this is how you evaluate the feedback".

If there is a specific episode in that playlist that does those 3 things, please point me to it. Other than that it's more hunting and pecking.

Yes, this is the starting point which I meant to link:

Once you have watched that, you can watch the first few videos in the playlist I linked

 

[Dave Upton]

Good episode. I'm reasonably smart (but no expert) on Audyssey, having read up on it the past couple years. There's a detailed and indexed thread on AVS that discusses Audyssey in depth, that I've spent time on.

I hadn't heard the tips that Dave gave about Audyssey getting tripped up by bass room modes, and working around that with pre/post bass volume changes. Similarly, I've not played with bass timing settings after calibration. I'll give those a look next time I run audyssey. (I do it way too much, because I'm chasing after / working around some futzy subwoofer issues.)

Dave said out loud what I've been thinking but don't readily find said explicitly online: Audyssey is coasting on their brand name, having abandoned new engineering upwards of a decade ago.

This might have convinced me to go for Anthem and ARC when I upgrade pre-pro.

I also don’t want to sell Dirac short - it’s a fantastic system. I just find the number of available processors with Dirac is still a bit small and there are other trade offs.

Since they added DLBC (Dirac Live Bass Control) they are definitely a much improved solution and I plan to review it again in the near future to compare against ARC Genesis.

 

[Todd Erwin]

Gee, Brian, I didn't beat you up that bad....

 

[Brian Dobbs]

Gee, Brian, I didn't beat you up that bad....

I'm just kidding you bro. I totally respect how much you know about streaming. It's quite impressive. I'm happy that you've been a part of this whole thing and look forward to future discussions. I just am making light of my position on the subject. Sorry if I chose my words poorly.

 

[Todd Erwin]

Great show, finally finished listening last night.

@Sam Posten , in the GBU segment of the show, you talked briefly about Star Trek Discovery on CBS All Access being in Dolby Atmos on your Apple TV. With the rebrand launch today of Paramount+, I checked a few episodes from seasons 2 and 3 on my Apple TV 4K, and all I could get was PCM 5.1.

 

[Sam Posten]

Bleh

 

[John Dirk]

Audyssey is really, really stupid. What is is looking at is likely a massive peak due to room gain. There are two ways to work around this.

1) What I will typically do to defeat Audyssey's stupidity is pre-EQ the sub using a miniDSP device - which can be had cheaply. This takes about 15 minutes using REW and a UMIK. Here's a great guide you can follow:

2) If DSP is too much effort, here's the trick. This is something I typically do with a piece of painters tape and a marker or pencil. Put the tape on the amp plate so you can mark next to the gain knob. Note how much you have to twist the gain knob for 3dB. Now run Audyssey, and adjust your sub gain down until Audyssey doesn't throw an error on the initial level check. Be sure to check the level it's putting out with an actual SPL meter - it will typically be 65-68 dB. Then, between level checking in Audyssey and starting the measurement process, turn it up by 3dB on the gain knob.

This will raise the measurement levels enough to make Audyssey more accurate, but not enough to cause any issues. Then, once calibration is done, you can level adjust the sub to match the mains at 75dB. This usually yields a far better calibration than Audyssey will alone.

Just received my UMIK-1 today and viewed the above guide. It has a lot of good information on sub and crossover setup but doesn't specifically discuss the use of REW. I'm sure I can find the correct guide so hoping to play around with it later this evening.

 

[Dave Upton]

Just received my UMIK-1 today and viewed the above guide. It has a lot of good information on sub and crossover setup but doesn't specifically discuss the use of REW. I'm sure I can find the correct guide so hoping to play around with it later this evening.

I posted this in another thread, but here's a great REW primer:

 

[JohnRice]

Just received my UMIK-1 today and viewed the above guide. It has a lot of good information on sub and crossover setup but doesn't specifically discuss the use of REW. I'm sure I can find the correct guide so hoping to play around with it later this evening.

Weird coincidence. Mine is arriving today as well.

 

[John Dirk]

I posted this in another thread, but here's a great REW primer:

Thanks Dave. I spent some time this evening and was able to complete some sweeps of my SVS PB12 Plus/2. Based on the results I'm assuming [hoping] I did something wrong. I basically loaded the calibration file, disconnected my LCR speakers and then had REW do a sweep from 0 - 130 Hz. As you can see below, my sub drops completely to the floor at about 80Hz. I used the generator to run a slower sweep and the results were identical and easily confirmed by my ears. I'll definitely take a look at this new tutorial and give it another try.

 

[JohnRice]

Thanks Dave. I spent some time this evening and was able to complete some sweeps of my SVS PB12 Plus/2. Based on the results I'm assuming [hoping] I did something wrong. I basically loaded the calibration file, disconnected my LCR speakers and then had REW do a sweep from 0 - 130 Hz. As you can see below, my sub drops completely to the floor at about 80Hz. I used the generator to run a slower sweep and the results were identical and easily confirmed by my ears. I'll definitely take a look at this new tutorial and give it another try.

View attachment 91948

It looks like your crossover is set at 40Hz. Plus, I can't believe you're getting that kind of output all the way down to 10Hz.

 

[John Dirk]

It looks like your crossover is set at 40Hz. Plus, I can't believe you're getting that kind of output all the way down to 10Hz.

Yea, honestly I don't know what to make of it just yet. The fronts were crossed at 40Hz but they were disconnected anyway for this sweep. The subs crossover was disabled which should have placed the Marantz in control. Maybe I need to try it again with Audyssey turned off since [of course] I have no way of knowing what it might be doing to the curve. Will be interesting to see your results since we have the same sub.

 

[JohnRice]

The fronts were crossed at 40Hz but they were disconnected anyway for this sweep. The subs crossover was disabled which should have placed the Marantz in control. Maybe I need to try it again with Audyssey turned off since [of course] I have no way of knowing what it might be doing to the curve. Will be interesting to see your results since we have the same sub.

It sounds like the crossover was set to 40Hz, and the graph certainly exhibits that. Even if the speakers are disconnected, the crossover was probably still at 40Hz.

 

[JohnRice]

Well, my calibration stuff is here and we're projected to get as much as three FEET of snow through the weekend. So, I won't be going anywhere until Tuesday, once I get home this afternoon. Maybe I'll have a chance to try the stuff out. Hopefully the power stays on and my roof doesn't collapse.

 

[JohnRice]

I posted this in another thread, but here's a great REW primer:

He goes so fast. He needs to explain what he's doing a little better. Especially the settings in REW.

 

[Dave Upton]

Thanks Dave. I spent some time this evening and was able to complete some sweeps of my SVS PB12 Plus/2. Based on the results I'm assuming [hoping] I did something wrong. I basically loaded the calibration file, disconnected my LCR speakers and then had REW do a sweep from 0 - 130 Hz. As you can see below, my sub drops completely to the floor at about 80Hz. I used the generator to run a slower sweep and the results were identical and easily confirmed by my ears. I'll definitely take a look at this new tutorial and give it another try.

View attachment 91948

Questions that spring to mind:

What is your LPF of LFE set to in your AVR?
Do you have a lowpass filter set on the SVS?

Make sure Audyssey is off for your measurements - that is absolutely essential.