Calibrating multichannel AVP/AVR system with Audiolense

Thread Starter
Oct 26, 2023
Preamp, Processor or Receiver
Marantz 7703
Main Amp
Parasound A51
Additional Amp
Parasound A23
Front Speakers
Center Channel Speaker
Surround Speakers
B&W 682S2
Surround Back Speakers
B&W 682
ELAC 2070
Video Display Device
Samsung QE65QN95AATXXH
Streaming Subscriptions
Tidal, Netflix, HBO Max, Disney+, Amazon Prime, Showtime
Other Equipment
Playstation 5
I want to share my experience and what I have learned through the calibration process of my 7.1 AVP system using REW and Audiolense XO.
I think I finally managed to get the most out of my room and the equipment I got. It was a tedious and lengthy process to experience what and how to do PC-based DRC through an AVP.
I know other users are also interested in using Audiolense to calibrate their AVP/AVR multichannel system and maybe I can provide very basic guidance or a few tips on how to do it.
I do not have a designated listening room and equipment worth 10000s of bucks. Also, I am not professional in the topic. Just want to get out the best of my system and help others if I can.

My system is 7.1:
Source: Gaming PC
AVP: Marantz 7703 (with Audyssey DRC)
Amplifiers: Parasound A23 and A51
Fronts, center: ELAC speakers
Subwoofer: ELAC 2070 with auto and manual 8-channel PEQ calibration
Back and side: B&W shelf speakers

I mainly use a PC for playing games, listening to music, and watching movies in a room got very bad acoustics. Audyssey could not do too much and I placed absorbers behind the front speakers and bass traps in the front corners years ago. Those absorbers helped a lot and I got curious how the sound could be improved more despite the bad acoustics.

I found Audiolense (among other PC-based DRC software) and bought it 4 years ago.
Back then I just autocalibrated the sub and created different correction filters for low-latency gaming and best-quality music listening and movie watching. Back then I used VB Asio Bridge and FlexASIO with Audiolense convolver for system-wide sound. (I switched to Virtual Audio Cable + ASIO4ALL + HLC. VAC got much better performance and sound quality.)
Both Audiolense and its convoler are one of the most unstable software I have ever used and I am a professional IT guy and software developer but I got to know their issues and learned how to avoid the crashes as much as possible.

My first listening experience was good and used Audiolense for a year. The reason I stopped using it was that it consumed too much resource on my PC and gave another try to my AVP's Audyssey. I decided not to use Audiolense and live with the lower audio quality. Recently I upgraded my PC and decided to check how it can run the convolver and games together now.

Because my new PC can run everything I decided to make a new calibration but took it very seriously. I made a step-by-step list:
1. Move the speakers to their right positions
2. Set speaker distances in AVP
3. Set speaker volume levels
4. Subwoofer calibration
5. Align the phases of the subwoofer and the nearest front speaker (in my case it is the front left speaker)
6. Fine-tune speaker distances in AVP with Audiolense
7. Measurement and filter creation

There is some important information to provide in order to understand why I did what and how I did:
AVP/AVR gears might work and their settings might called differently. Audiolense XO creates crossover and routes the sound from other speakers to the subwoofer.
This is where a few important things come into account because AVP must not change the sound and neither do crossovers so it won't route any sound to the LFE channel. All the job is done by Audiolense and the convolver.
Therefore all functions that modify the audio signal should be disabled in AVP. (Except speaker levels and distances. These play an important role. More later on.)
Let's see how I calibrated my system.

AVP settings:
Audio mode: Pure Direct for the best quality and get rid of crossover/channel routing of AVP
LFE surround parameter: -10db
Speakers: all are large
Crossover: minimum
Subwoofer LPF: maximum
Bass mode: LFE (not LFE+Main)
2-channel playback: Auto
Audyssey: everything is off
Dialog level adjustments: off
Subwoofer level adjustment: off
Lipsync: off

Use these settings in every step except when I describe if a setting should be set to anything else. In that case, do not forget to revert back the changed settings to the ones above.

LFE surround parameter: The LFE channel is amplified by 10db for multichannel audio to maintain more dynamic and headroom. It is done by AVP/AVR or it might also be done by media players.
(More info:
The system is going to be calibrated with Audiolense for general usage like music listening and gaming etc. LFE boost is disabled with this setting and gets rid of the LFE boost by AVP.

Speakers are set to large and bass mode is set to LFE to avoid routing other channels to the subwoofer. The sweeps should not be routed to another speaker at all during measurements because the speakers themselves alone must be measured.
Side note: Marantz 7703 disables all processing circuits in pure direct mode and works as a pure preamplifier. It does not do crossover either. Channels are routed to LFE only if the bass mode is set to LFE+Main. The full frequency range is routed and does not crossover at all in this case as far as I know.
Despite AVP not doing crossovers and routing channels to LFE with the settings above I also set crossover and subwoofer LPF to their minimum and maximum respectively just in case AVP would route any signal to LFE. We never know for sure how an AVP works in particular circumstances. :praying:

Other parameters are self-describing: turn off all signal-changing settings.

Other settings:
- The gain level of UMIK-1 (or other) mic in Windows should be 0db. You can change the unit type in Windows by right-clicking on the gain slider in the mic's sound control panel.
- Maximum output volume level in Windows for the device used for measurements.
- The whole process must be done with 5.1, 7.1, etc. (multichannel) mode in Windows. AVPs boost LFE channels only and do not boost channels that are routed to LFE. This is needed the way I calibrated the sub but can be done another way.

Subwoofer preparation:
Phase: 0 as the starting value
Delay: 0ms as the starting value
LPF: maximum

Let's go through the calibration process I used.

1. Move the speakers to their right positions

There are many guides and proposals on where should the speakers be placed for various audio systems.
Move the speakers to the right position as close as possible according to the MLP (main listening position) to avoid unnecessary digital processing (correction).

Take care of toe-ins as well.

I am a quite precise person so I used a laser measuring tool to move the speakers to their right position as much as possible according to the MLP (main listening position).
UMIK-1 mic was placed at the MLP and directed up to the ceiling.

In my case the distances are equal for the next speakers:
1. front left and right
2. the center is placed in line between the fronts
3. side left and right
4. back left and right
5. the subwoofer sits next to the front left

2. Set speaker distances in AVP
Use the general AVP settings. Measure the distances and enter them in AVP.

3. Set speaker volume levels
Special AVP setting for this step:
LFE surround parameter: 0db

Use the mic and REW's SPL meter to determine the levels of each speaker and set the level in the AVP accordingly. Use the AVP's test tone function. Equalize the volume levels of all speakers in AVP. I am sure there is no DRC software that could equalize too much difference in levels and distances. With that, we made sure that Audiolense computes simpler filters with better dynamics and quality. Take note that the volume for the sub should also be set independently so there won't be too much difference between the sub and other speakers.

4. Subwoofer calibration
Use the general AVP settings.

The general measurement level is 75db but I used 85db for LFE because I decided to calibrate the subwoofer for the LFE boost which is used for multichannel movies.
Target db can be achieved using the volume level of the AVP and/or changing the output level in the REW measurement window. Do not increase the output level above 0db there. Much better to keep it at -10db at least to have headroom. Increase the volume on the AVP instead.
I do not know if I am right but I think I get better results in general if I calibrate the subwoofer this way. Though the general calibration level I use in the end is 75db.
Make sure that the LPF on the sub is set to its maximum in order to measure its full frequency range.

My sub got 8 parametric EQ configurable both automatically and manually and I used its autocalibration first.
The measured result was not bad but I was sure I could make better.

Turned off its EQ and measured the raw frequency response with REW to check improvements during calibration and create a target curve for its characteristics in the room.
Target creation is done with REW's EQ tool based on the raw measurement curve.

LFE target curve settings.png

The best curve settings for the raw response at 85db target

LFE raw-target.png

Elac 2070 raw (uncalibrated) response and the generated target curve

I created the filters with the EQ tool and converted the Q values to ELAC 2070 width values. The measured result was not much better and was not close to the simulated result in REW. I think it is normal. REW does not measure and take room acoustics into account and the simulation is just a simulation, not the real world. Therefore I manually corrected the filters in ELAC's application measuring every change until I found the best settings.

LFE raw-target-result.png

ELAC 2070 base calibration result

5. Align phases of the subwoofer and the front left speaker

Use the general AVP settings and measure the response of the nearest front speaker to the subwoofer at 75db level.
Why did I measure the sub at 85db and the front at 75db? As I already mentioned I wanted to calibrate the sub for the industry standard which is 10db boost on LFE. I checked the result and the curve shape was the same regardless of the LFE boost (LFE surround parameter).

LF raw.png

Front left raw response

Change the next AVP settings in order to do crossover and route channels to sub:

Audio mode: Auto
Speakers: set the size of the front speaker that is the nearest to the sub to small (if you want to be sure set it all to small :praying:)
Crossover: 80Hz (or another one that suits the most for your sub and speakers)
Subwoofer LPF: 80Hz (or another one that suits the most for your sub and speakers)

These settings are needed to check the result because the measurement sweep is going to be sent to the nearest front channel which is then routed to the sub by the AVP according to the crossover and LPF settings above.
Increase the volume of the sub by 10db to simulate the LFE boost. Increasing the LFE in the AVP would not do much because routed channels are not boosted. AVPs only boost the LFE channel.

Select REW's alignment tool and find the phase and delay for the sub.
As a starting point, I used this guide:
I do not use miniDSP and independent woofer, tweeter, etc. but the method is similar. The main difference is that I had to use the raw FL as the first and the raw LFE as the second curve in the alignment tool to get the correct values.
Enter the computed values into the sub and measure the result. If you think it could be better just fine-tune the settings until you get the best response.
Finally, revert the increased subwoofer volume level to the original value.

LFE+FL result.png

Result curve of aligned sub and front left

It is seen on the image that the LFE channel is boosted by 10db and the response curve is falling off to 75db to the front left curve. My subwoofer calibration was done.

6. Fine-tune speaker distances in AVP with Audiolense

Use general AVP settings and Audiolense for quick measurements. Measure the speakers and check their delays. Change the distance of each speaker in AVP then repeat the quick measurement until the difference between the speaker delays is minimal.
I successfully kept them very close. My sub was the base with 0ms.

Spkr delays.png

Speaker delays

7. Measurement and filter creation
I won't explain in detail how to measure and create filters etc. There are many posts about these topics but I take note of a few important things.

- Take care of the volume levels of the sub and other speakers. Now all speakers, including the sub, should be at the same level. Make sure the LFE surround parameter is set to -10db. Do not measure the sub with the 10db LFE boost!

- Always check noise removal and change them manually if something sounds strange or you think it could be better. The result might be dramatically different even if a noise removal start point is moved away by 0.1ms only. Especially for subwoofers. You can check the automatic noise removal and change them for each channel under the Advanced TTD Correction menu. Play them a little bit if you have to and test the created filter. Noise removals can be reset to their automatically computed values. The help file includes an explanation of this function.

- Do not be afraid of using different crossovers for each speaker if it is needed. Check the filtered and simulated result for each one and if there is a dip or bump near the crossover frequency try to change the XO for that speaker. Measure and check the result with REW and change the settings accordingly. I got the best frequency response and sound using different XO-s.

XO settings.png

Final crossover settings

The result in my case is astounding compared to the one I had before. Audiolense can work wonders for bad room acoustics as well. :banana:
AVP is used in Pure Direct mode which provides much better sound quality with Audiolense XO than Audyssey ever be capable in Auto Mode.

The LFE surround parameter might have to be changed depending on what I am doing. Usually, it should be -10 for music listening, etc. but 0 when I am watching multichannel movies for example.
Marantz 7703 can store 4 presets and they can be quickly restored by pressing a button. I saved one preset with LFE boost enabled and one for LFE boost disabled. I just quickly switch between them when I need to.

A drawback is that Audyssey cannot be calibrated with the AVP because it overwrites the manually set parameters. I have not done it yet but probably Audyssey calibration can be executed and revert back to the changed settings: speaker sizes, crossovers, etc. Check how Audyssey sounds. In my opinion, it should be okay. In case the calibration does not sound well with the settings configured to Audiolense there is a solution that I have not tried yet.
Audyssey calibration files can be created on a PC and sent to the AVP with the Audyssey App for example. That way the measurements and calibration can be done using REW and speaker parameters that I set manually during the calibration. One example can be found on Audyssey A.R.T YouTube channel. I am sure this Audyssey calibration method is gonna be much better than the one that the AVP does.

A concern could be raised here. The filter does the crossover and routes low frequencies from other channels to LFE. What about if I want to use the AVP but do not use the convolver? Speaker size, crossovers, and LFP cannot be saved as a preset on the AVP. Should these AVP settings be changed every time when enable or disable the convolver or just use the Netflix application on TV as the source? It would be very annoying.
Do not have to change them at all since the AVP does not do crossover and channel routing in Pure Direct mode!

I set the size of all speakers to small and also configured their crossovers and the LFP for the bass for normal usage (no convolver) and created 3 AVP presets:
1. Pure Direct mode and LFE boost enabled for watching movies on the PC.
2. Pure Dircet and LFE boost disabled if I find the boost too much.
3. Auto mode for using the AVP and Audyssey when the source is not the PC or the convolver is not used (AVP does the crossover and routes the channels).

This way both Audyssey and the convolver work flawlessly without interfering with each other despite they need different crossover settings

English is not my native language but I tried being unambiguous. Grammar suggestions can be sent privately and I correct them. :)
Sorry, I could not add links yet so I had to remove them. :unbelievable:
I know it is not a detailed guide but it could be a general guideline for those who would like to use Audiolense sending the audio to the AVP/AVR through HDMI.
Please let me know if something should have been done better.

I edited the Epilogue since I found a solution for the crossover issues! :jump:
Last edited:


Nov 24, 2020
Nice post.

I use a Denon AVR.

I have a lightly different purpose to you because each amplifier channel output is connected to separate speaker drivers
DSP crossover is done for each channel.

But overall process is the similar to you - instead of 8 channels for 8 speakers I use 8 channels for 8 drivers.

I run in Pure Direct mode of course.

It's a great solution for 1 box - multichannel DAC, multichannel amps with over 150W into 4 ohms, and remote control for volume.

The cool thing about Denon and Marantz is the volume control is actually analogue IC chip.

So when you run in Pure Direct, all DSP is done before the AVR.
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