The astounding new AS-EQ1 SubEQ goes on sale!

[Ed Mullen]

CharlieU wrote:

I think there should be a note in the Level Matching section for people running systems with automatic room correction to just use the Master Volume control to set the 75db level for the Left/Center. Using the auto setup on a receiver/processor already matches the levels of your mains, center, surrounds and backs. Playing with the individual trims is going to throw that off. Most people will run the auto setup to get their distances and levels set even if they don't use the room correction. Come to think of it, even when I had systems without auto setup, I always set distances and levels as part of my setup of the receiver.

If your AVR runs auto-set-up, then it will reference 75 dB (or very close to it) for all the speaker channels. There is usually some deviation - you might see 74-76 dB on an SPL meter.

The issue to keep in mind is that the AVR mic and the AS-EQ1 mic will likely have somewhat different absolute SPL readings - meaning for a given test tone one will read slightly different that the other. We're not worried about absolute SPL so much as we are concerned with level matching the speakers and subwoofer before the AS-EQ1 is run.

So if you change the connected Sat speaker by a given amount to achieve 75 dB, then adjust all the other speaker channels by the same offset - that will preserve the differential between speaker channels that your AVR may have set during auto-EQ.

Let's consider the following example:

After auto-EQ, here are your AVR trim settings:

FL: -2
C: 0
FR: -2.5
SR: +3
RSR+ +5
RSL: + 5.5
SL: +3.5

You connect the AS-EQ1 to the center channel multi-channel input and it reads 77 dB, meaning you would need to bump it down 2 dB to get 75 dB. If you want to preserve the existing ratio between all your speaker channels and not bother measuring the rest of them, just bump them ALL down 2 dB and then set the subwoofer to 75 dB.

Again, the key is to make sure the speakers and subwoofer are level matched as read by the same microphone before running the EQ step for the subwoofer. Because the trim level setting the AS-EQ1 generates is absolute, not relative - you actually input that value into your AVR.

The only other alternative is to set the subwoofer to 75 dB, run the EQ step, and then run your auto-set-up in your AVR and hope the subwoofer trim level falls within the control range of your AVR (it should in most cases). This is certainly an easier route, but it's not as optimal as the "long way" because it gives the AVR an opportunity to create an EQ correction file which it will then apply over the AS-EQ1. In most cases the AVR won't do anything untoward to the subwoofer, because it already sees a very nice FR from the AS-EQ1. But we can't control what the AVR will do to the subwoofer channel in every set-up and with every AVR model, so it's safer to do it the long way as described in the manual.

[CharlieU]

Ed Mullen wrote:

You connect the AS-EQ1 to the center channel multi-channel input and it reads 77 dB, meaning you would need to bump it down 2 dB to get 75 dB. If you want to preserve the existing ratio between all your speaker channels and not bother measuring the rest of them, just bump them ALL down 2 dB and then set the subwoofer to 75 dB.

We're on the same horse, just facing different directions. You run auto setup, your speaker ratios are now set. You hook up the AS-EQ1 to the center channel and the AS-EQ1 microphone and use the Master Volume control to adjust to the 75dB level. Since using the Master Volume control doesn't change the ratios, there is no need to go back in and adjust the trims for the other channels. Of course to complete the task, use the Gain knob located on the subwoofer(s) to get them to the same 75dB.

The above is based on my belief that the auto setup done by Pioneer, Denon, Yamaha, et al will result in equal sound levels from all my speakers at my listening position. Machines can't lie, can they?

The method described in the manual is good for people without auto setup or that don't run auto setup. Plus, who wants to dig out a manual to figure out what volume setting is reference? (Ok, everybody other than me.)

[Ed Mullen]

CharlieU wrote:

We're on the same horse, just facing different directions. You run auto setup, your speaker ratios are now set. You hook up the AS-EQ1 to the center channel and the AS-EQ1 microphone and use the Master Volume control to adjust to the 75dB level. Since using the Master Volume control doesn't change the ratios, there is no need to go back in and adjust the trims for the other channels. Of course to complete the task, use the Gain knob located on the subwoofer(s) to get them to the same 75dB.

The above is based on my belief that the auto setup done by Pioneer, Denon, Yamaha, et al will result in equal sound levels from all my speakers at my listening position. Machines can't lie, can they?

The method described in the manual is good for people without auto setup or that don't run auto setup. Plus, who wants to dig out a manual to figure out what volume setting is reference? (Ok, everybody other than me.)

Here's the rub with your method:

1) You run auto set-up and the AVR sets all your trim levels.
2) Then you connect the AS-EQ1 and run the Sat test tone and adjust the Master Volume until the Sat reads 75 dB.
3) Let's say (for the sake of argument) that you need to set the master volume to +4 in order to obtain 75 dB from the center channel.
4) Then you run the subwoofer tone and adjust the subwoofer gain so it reads 75 dB.
5) Then you run the sub EQ step, and input the subwoofer trim level into your AVR.

The subwoofer calibration level will now be incorrect by exactly 4 dB.

The voltage being sent to the speakers and the subwoofer has a fixed ratio at any Master Volume setting. That ratio can only be altered through the use of the trim controls. Altering the Master Volume setting such that the voltage to the speaker input changes inherently unbalances the level matching step because the voltage from the AS-EQ1 test tones is the same as the voltage the Master Volume sends to the speaker/sub channels at 0.0, unless you change the trim levels.

The best way to think of it is that setting the subwoofer to 75 dB by adjusting the gain is identically analogous to setting a speaker channel to 75 dB by adjusting its trim level.

Bottom line is you have two options in order to obtain the correct subwoofer calibration level:

1) Follow the AS-EQ1 Operator's Manual method.
2) Run SubEQ first, and then run auto-set-up afterward and hope the AVR a) doesn't run out of sub trim level adjustment, and b) doesn't negatively affect the subwoofer FR by overlaying its own EQ file on top of the SubEQ file.

If you are willing to run those two risks, by all means select option 2, because it's easier and faster. As the OEM, we don't have the luxury of advising option 2 in the OM because of the risks involved. Option 1 is more work, but it results in a correct subwoofer channel trim setting and an optimal subwoofer EQ file.

Regardless, your proposed method above will not work, and will result in the subwoofer calibration level being incorrect by exactly the amount of Master Volume offset (from 0.0) required to obtain 75 dB at the Sat channel. That may be a negative or positive MV adjustment, it may be a large or small offset - but it will be an offset nonetheless and the AS-EQ1 will not realize this.

[DougMac]

Ed,
I noticed in the instruction manual there's a way to print the before and after results. I hope you'll be encouraging your customers to send the results to you. I'd love to see the results folks achieve in the real world. I'm sure it will be a great marketing tool as well.

Doug

[Ed Mullen]

DougMac wrote:

Ed,
I noticed in the instruction manual there's a way to print the before and after results. I hope you'll be encouraging your customers to send the results to you. I'd love to see the results folks achieve in the real world. I'm sure it will be a great marketing tool as well.

Doug

Thanks Doug - I hope all users post their results at the various forums. It would indeed be cool to see the various set-ups and how the AS-EQ1 handled them.

We improved the FR chart size and vertical/horizontal scale resolution (compared to the Pro version) specifically for this reason - so customers can see in detail the FR results and share same with others without needing a magnifying glass to look a thumbnail FR chart like Pro provides.

[CharlieU]

Ed Mullen wrote:

Here's the rub with your method:

1) You run auto set-up and the AVR sets all your trim levels.
2) Then you connect the AS-EQ1 and run the Sat test tone and adjust the Master Volume until the Sat reads 75 dB.
3) Let's say (for the sake of argument) that you need to set the master volume to +4 in order to obtain 75 dB from the center channel.
4) Then you run the subwoofer tone and adjust the subwoofer gain so it reads 75 dB.
5) Then you run the sub EQ step, and input the subwoofer trim level into your AVR.

Ed,

You got me at step 5. While I knew I had to enter the distance in the AVR, I totally blew by that step. (Probably because it destroyed my theory) Sorry to have been such a pain in the posterior. I should know better than to contradict the experts. Excuse me while I head off to the Brain Surgery and Rocket Science Forums. I have a bunch of posts to delete on those forums.

[Sonnie]

Hey Charlie... delete mine while you are over there.



We will definitely start a before and after thread for FR graphs...

[Ed Mullen]

CharlieU wrote:

Ed,

You got me at step 5. While I knew I had to enter the distance in the AVR, I totally blew by that step. (Probably because it destroyed my theory) Sorry to have been such a pain in the posterior. I should know better than to contradict the experts. Excuse me while I head off to the Brain Surgery and Rocket Science Forums. I have a bunch of posts to delete on those forums.

Don't feel bad, Charlie - we initially had the same exact line of thinking when setting up the AS-EQ1 with our own auto-EQ AVRs.

The level matching routine with the AS-EQ1 is really no different than how you would manually calibrate an AVR - you're just using the AS-EQ1 for the test tone generator instead of the internal AVR tones. So you set the master volume to 0.0, and then only adjust the speaker trim levels. Since the subwoofer is not connected to the master volume of the AVR during the level matching routine, altering the master volume to obtain the desired SPL (instead of using the trim controls) will essentially trick the AS-EQ1 into providing you with a bogus trim level for the subwoofer channel.

The level matching step is probably the most awkward step of using the AS-EQ1, but we ultimately discovered it was necessary in order to obtain the correct subwoofer trim level.

[robbroy]

CharlieU wrote:

Ed,

You got me at step 5. While I knew I had to enter the distance in the AVR, I totally blew by that step. (Probably because it destroyed my theory) Sorry to have been such a pain in the posterior. I should know better than to contradict the experts. Excuse me while I head off to the Brain Surgery and Rocket Science Forums. I have a bunch of posts to delete on those forums.

You could put that post under the definition of Class.

-Robb

[htnut12]

Mine has been on preorder from the beginning. I have downloaded the manual, read this thread, and understand the level matching. I do have one question. If I were to set my volume to 0.0 on my Pio 94, and input anything with the least bit of bass, my house would structurally fail. I have a four IXL-18 IB that outputs prodigious amounts of bass energy. That sub is now matched to Klipsch speakers which are very efficient. I hope that if I do set the receiver to 0.0, that the AS-EQ1 outputs a very small signal to the attached speaker and sub. No problem really with the speaker, but if I cause damage to the house, no amount of explaining to the lovely wife will suffice.