Taking Measurements For Audyssey Calibration

[Pogre]

Never seen that meter before, but I'd guess it's better than a phone app meter! Lol
I can't say one way or another about your mic placements. I will disclose the level of my own OCD though lol. IMO, laying the seat back only benefits you if you actually listen that way. I have a couple of gel insert pillows(like the kind for your bed) that I set on my couch and then place my audyssey mic, and umik on for measurements. IMO this replicates my body density and to my little brain, audyssey should EQ as if I were in my seat. Just .02 loco pesos!!!

Omg that's something I could totally go overboard on too! So, is it the seating position or 6" from the back of the chair? I couldn't do both...

I did run it about 4 more times because I felt I could position the mic better and more consistently the same distances apart. Plus one time I forgot to plug one of the ports for my subs and set eq1.

 

[lovinthehd]

One thing that stands out is the microphone isn't level; you want the mic pointing straight up (i.e. the flat tip level to the floor/ceiling) as much as possible. Never saw the cardboard tripod before....I got one of these with an amp purchase

 

[Pogre]

One thing that stands out is the microphone isn't level; you want the mic pointing straight up (i.e. the flat tip level to the floor/ceiling) as much as possible. Never saw the cardboard tripod before....I got one of these with an amp purchase

That's nicer, but mine was free. Or did they send that with your amp?

When I did the last one I actually thought of that and had the mic level for all 8, by standing the tube straight up in the crevasses of the chair. That's the one I did over after setting the subs on the proper mode for calibrarion. Hsu recommends 1 port open, and eq1. I popped the ports and changed the settings when I was listening earlier and forgot.

 

[lovinthehd]

That's nicer, but mine was free. Or did they send that with your amp?

When I did the last one I actually thought of that and had the mic level for all 8, by standing the tube straight up in the crevasses of the chair. That's the one I did over after setting the subs on the proper mode for calibrarion. Hsu recommends 1 port open, and eq1. I popped the ports and changed the settings when I was listening earlier and forgot.

How effective these changes/tweaks are I really don't know but have followed the advice of others for this type of mic for placement for consistency if nothing else. I used a mini-tripod with things to stand it on for a while but the mic stand was free with a very good amp price, so....

 

[Pogre]

How effective these changes/tweaks are I really don't know but have followed the advice of others for this type of mic for placement for consistency if nothing else. I used a mini-tripod with things to stand it on for a while but the mic stand was free with a very good amp price, so....

Yeah, I get that, but I'm the type that'll try almost anything to tweak stuff (within reason). I'm still finding little improvements and I've had this system a little while now.

 

[lovinthehd]

Yeah, I get that, but I'm the type that'll try almost anything to tweak stuff (within reason). I'm still finding little improvements and I've had this system a little while now.

I like that you're going in without necessarily abiding by particular rules....

 

[Hi Ho]

I would just download an SPL meter app on your phone. A good iPhone SPL app is "SPL Meter" by Studio Six Digital. It actually looks like a classic Radio Shack meter. I'm sure there are good apps for Android as well. I do believe the apps for iPhone are more accurate since they can adapt the app for each model of iPhone because there are not many variations of them that would affect the SPL measurements. In the Android world it is pretty much a crapshoot since there are so many makes/models. I actually found this study pretty interesting: http://asa.scitation.org/doi/full/10.1121/1.4865269

 

[Pogre]

I would just download an SPL meter app on your phone. A good iPhone SPL app is "SPL Meter" by Studio Six Digital. It actually looks like a classic Radio Shack meter. I'm sure there are good apps for Android as well. I do believe the apps for iPhone are more accurate since they can adapt the app for each model of iPhone because there are not many variations of them that would affect the SPL measurements. In the Android world it is pretty much a crapshoot since there are so many makes/models. I actually found this study pretty interesting: http://asa.scitation.org/doi/full/10.1121/1.4865269

I actually ended up doing that. I tried 4 or 5 different apps and found one that seems to be sensitive enough. It would go up, db by db pretty much with the volume on my avr. I level matched them at 69db.

I set the gain on 1 and turned volume up on my avr until it hit 69db. I pulled it out of its spot and slid the other one into the same spot. Left the volume on my avr where it was and used the gain on the back of the sub to dial that one in at 69db also.

I contacted Hsu about this and they said it's not uncommon; The gains on the subs don't match, but I have them at the same level now. One of them is right on the line below 12 o'clock and the other is a little more than halfway to 12 o'clock. Does that sound right?

 

[William Lemmerhirt]

I actually ended up doing that. I tried 4 or 5 different apps and found one that seems to be sensitive enough. It would go up, db by db pretty much with the volume on my avr. I level matched them at 69db.

I set the gain on 1 and turned volume up on my avr until it hit 69db. I pulled it out of its spot and slid the other one into the same spot. Left the volume on my avr where it was and used the gain on the back of the sub to dial that one in at 69db also.

I contacted Hsu about this and they said it's not uncommon; The gains on the subs don't match, but I have them at the same level now. One of them is right on the line below 12 o'clock and the other is a little more than halfway to 12 o'clock. Does that sound right?

Fwiw, I wouldn't trust an app but hey, what are ya gonna do? Curious why you level matched the subs in the same location, instead of where they're used.

 

[Pogre]

Fwiw, I wouldn't trust an app but hey, what are ya gonna do? Curious why you level matched the subs in the same location, instead of where they're used.

Is that wrong? lol.
I thought the point was to get them at the same level. Didn't realise it was from 2 different spots. I'm pretty sure that's how Kevin said to do it on the phone.

That aside, assuming the app is close enough, is it unusual for gains on these subs to vary that much?

 

[William Lemmerhirt]

Is that wrong? lol.
I thought the point was to get them at the same level. Didn't realise it was from 2 different spots. I'm pretty sure that's how Kevin said to do it on the phone.

That aside, assuming the app is close enough, is it unusual for gains on these subs to vary that much?

Not surprised to see the gains different. Wouldn't sweat that as long as spl is within reason. Assuming the app is close enough, it will work for consistency anyway. I just don't believe the response curve of a mic made for human voice is accurate on subs. More OCD lol!!!
An easier way than moving your subs to measure is just turn one off. Set the level at say 72(just a number. You'll want the combined spl to equal whatever level you'll use. 75 to match the other channels, or whatever level "hotness" you like. I set mine at 80). Turn off sub one, and measure sub 2 and set to 72. Turn them both on and measure again. Should be close to 75. Trim to taste. The reason is , your room(and most) aren't symmetrical so spl support will be different. You kinda have that cubby space(front door?) on the right. Might not matter but it also might. Plus, why drag that beast around? Lol

 

[William Lemmerhirt]

I know this article is old so don't stone me. I still feel it relevant enough to add to a discussion like this one.
https://blog.faberacoustical.com/2009/ios/iphone/iphone-microphone-frequency-response-comparison/

 

[Pogre]

Not surprised to see the gains different. Wouldn't sweat that as long as spl is within reason. Assuming the app is close enough, it will work for consistency anyway. I just don't believe the response curve of a mic made for human voice is accurate on subs. More OCD lol!!!
An easier way than moving your subs to measure is just turn one off. Set the level at say 72(just a number. You'll want the combined spl to equal whatever level you'll use. 75 to match the other channels, or whatever level "hotness" you like. I set mine at 80). Turn off sub one, and measure sub 2 and set to 72. Turn them both on and measure again. Should be close to 75. Trim to taste. The reason is , your room(and most) aren't symmetrical so spl support will be different. You kinda have that cubby space(front door?) on the right. Might not matter but it also might. Plus, why drag that beast around? Lol

Yes, I believe it's working good enough for consistency, if not exact as far as accuracy. I have measured them separately without moving them. Like I said, I have lots of time on my hands right now so I'll do that again tomorrow. I've got a brand new Audyssey mic and I'm having some fun playing with the tripod!

*Edit: What test tone do you use and where do you set the volume on your avr for level matching?

 

[Pogre]

I know this article is old so don't stone me. I still feel it relevant enough to add to a discussion like this one.
https://blog.faberacoustical.com/2009/ios/iphone/iphone-microphone-frequency-response-comparison/

FWIW I use a large Samsung tablet. Probably uses the same type of mic tho.

 

[William Lemmerhirt]

FWIW I use a large Samsung tablet. Probably uses the same type of mic tho.

Here's an iPhone6 mic response, and an unspecified android phone. The android looks nice to about 58hz. iPhone drops much earlier.

 

[lovinthehd]

Gain matching vs level matching http://www.avsforum.com/forum/113-subwoofers-bass-transducers/1282064-two-subs-gain-matching-vs-level-matching.html

 

[William Lemmerhirt]

Yes, I believe it's working good enough for consistency, if not exact as far as accuracy. I have measured them separately without moving them. Like I said, I have lots of time on my hands right now so I'll do that again tomorrow. I've got a brand new Audyssey mic and I'm having some fun playing with the tripod!

*Edit: What test tone do you use and where do you set the volume on your avr for level matching?

I like to keep my trim around-3. I just use the built in test tone.

 

[Pogre]

Gain matching vs level matching http://www.avsforum.com/forum/113-subwoofers-bass-transducers/1282064-two-subs-gain-matching-vs-level-matching.html

Okay, boy. Yeah. I was gain matching. Duh. Sorry for all the confusion. I'm gonna read that thread HD linked me now...

 

[William Lemmerhirt]

Okay, boy. Yeah. I was gain matching. Duh. Sorry for all the confusion. I'm gonna read that thread HD linked me now...

I'm gonna read it too. 'Cept I'll never stay awake for 14 pages lol!

 

[Pogre]

Oh god no. I read that one page and got enough confirmation bias to know that gain matching works best in my room. Tomorrow I'm gonna drag them out, one by one and gain match them per one of the suggestions in that thread.

To gain-match identical subs, the most rigorous method is to move each sub to the middle of the room, place a mic very close to the driver, and measure the SPL. Then move each of the other subs to the exact same position with the mic exactly the same distance away, and set the level to the same SPL as the first one. I place tape on the floor around the first sub, so I can ensure the subsequent subs are located in the exact same place. I don't move the mic between measurements. This works for identical subs, and the level knobs should be at the exact same point, assuming the amps are consistent from unit to unit. It also works for different subs, but then you should expect different settings on the amps.

Mark Seaton was the one who suggested this method to me, and if it's good enough for him, it's good enough for me.

Craig