Help Interpreting Measurements

[Netkroozer]

Total newbie measuring home theater setup with 7.2 speaker layout. Where do I begin after capturing these measurements at the center(purple), left(blue) and right(green) seats?

 

[Wayne A. Pflughaupt]

Hard to decipher any one particular trace with them all overlaid like that, but that big hole at 100 Hz is definitely a concern. It almost looks like your speakers are rolling out at a much higher frequency than where the subwoofer starts. Knowing the speakers and subs involved would be helpful, as well as the crossover frequency you’re using.

Regards,
Wayne

 

[Netkroozer]

First thank you so much for your assistance.

I am in the process of upgrading a home theater in a house I recently purchased. I bought a pair of SVS SB16 Ultras. The CRL are ParadigmS wall speakers that will soon be replaced. I have set the crossover 80 hz.in a Marantz SR 8012 for this test. Interesting that you point out the drop off at 100 hz.I am not sure what to do with that.

 

[JStewart]

Very nice subs! Congrats. Welcome to forum too!

The dip in the measurements could have a number of causes in addition to the possibility of the xo set too low for the in walls. Measurements may be needed for someone to help with troubleshooting but before going there a question... have you run an Audyssey calibration since acquiring the sb16s and were the phase controls set to 0 and the low pass filters on the subs bypassed?

 

[Netkroozer]

Thank you for the warm welcome.

I have not rerun Audyssey. Also sub phases were set to 180 and 90. Should they be set to zero? Also LP was set to off. I will rerun Audyssey and see what happens.

 

[Netkroozer]

Also one other thing. When running Audyssey, it wants you to calibrate the sound of SBs to 75 hz which even setting SBs at 0 they cant get to that volume. Planning on calling SVS on Monday to get their thoughts.

 

[Netkroozer]

Here is the new measurement after calibrating Audyssey and setting phase to 0 on both subs.

 

[Netkroozer]

The above was with no smoothing. This one is with Var Smoothing applied

.

 

[Netkroozer]

Scale Adjusted to better highlight dip at 100 Hz

 

[JStewart]

Post Audyssey calibration appears slightly different but not better.

The steps to good bass are:
1. Best placement of subs in the room
2. Alignment of the subs to each other.
3. Alignment of the sub group/array to the mains.

This could be just a problem with #3 alone. You could use the REW RTA (real time analyzer) feature or take frequency sweep measurements while changing the sub distances equally for both subs fwd and/or backward in increments of 1 ft to see if the response smooths.out. If you should go past a point of max improvement then back up in smaller increments. You could also raise the XO to 90 and/or 100Hz to check that option. I recommend writing down your sub distances before starting so they can be put back. Turn off all soundfield processing (ex. dolby dsu, dts neural x, etc). Leave Audyssey on for this. It's my understanding that with Marantz after changing the distance you will need to back out of the change setting gui for it to actually be set. If you have no plans to move the subs and you do plan to use Audyssey going forward and you don't plan on adding new hardware such as a MiniDSP to manage the subs, this is your best choice.

Optionally, for a possibly better look at what's going on these measurements taken with
a) all soundfield processing off,
b) Audyssey off
c) a timing reference. Assuming a usb mic then it will be an Acoustic Timing Reference.
d) Take the sub "full range" measurements by changing the fronts to small and and the XO to the highest setting possible and disconnecting either the right or left front and sending the signal to it.
e) a range 10Hz to 300Hz

Front Right Full Range
Front Left Full Range
Sub 1 Full Range
Sub 2 Rull Range

They should show if there are obvious opportunities in the current set up or the in-wall speakers themselves.