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Why are modern AV Receivers so terrible?

xr100

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That I don't doubt. But the predicted post-EQ graphs will not necessarily be completely accurate as these non-linearities are not taken into account. Only actual measurements will show definitively how much better MultEQ XT32 is compared to XT, which I have not yet seen. @amirm maybe this could be an interesting test for you to do using the Klippel NFS?

The frequency response can be improved, at least on a certain axis. However, it will be affected by non-linear characteristics, e.g. power compression (or passive crossovers being affected by resultant impedance changes) as voice coils heat up. So, it's basically valid for "small signals," and non-linear characteristics are going to occur, anyway.

EQ'ing the "room" is another matter, of course.
 
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bobbooo

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I was hoping you might have some ideas :D Obviously you'd need one AVR with MultEQ XT and one with XT32. I don't know the exact details of your testing set-up so not sure if this would be possible or even make sense, but I was thinking maybe you could run through the Audyssey calibration for each AVR using a particular passive speaker, save the predicted post-EQ graphs, then run the NFS measurements on this same speaker, but replacing the amp you usually use for testing with one of the AVRs with the previously calibrated Audyssey EQ engaged, then do a second set of measurements using the other AVR also with its calibration turned on. The difference in the two sets of measurements should then show the difference between the measured post-EQ responses using XT and XT32 - let's call this delta_measured. The difference between the predicted responses for XT and XT32 we'll call delta_predicted. Then if you subtract delta_predicted from delta_measured you should get the error, if any, in the predicted responses (which may be due to non-linearities).
 
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markus

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As I understood, speakers are not perfect LTI systems, so the measurements could differ from the predictions.

The error is insignificant as long as you don't remove a wall between measurements or drive your speakers into distortion.

I did already look there but couldn't see a direct comparison of post-EQ graphs between MultEQ XT and XT32 of the same speakers in the same room. Do you have a link to any such comparisons?

I would need to search through the thread just like you.

XT32 offers more filter taps so you get better resolution at lower frequencies where it is needed most.
 
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Dimifoot

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The Klippel won't be of any help when comparing Room Eq software predictions/results.

What's needed is a REW post calibration measurement, averaged from multiple positions in the Listening Area+Main Listening Position or using the Moving Microphone Method.

Its quite easy to set it up as a test, you only need time and the AVRs that are equipped with the software for comparison.

The results can also be compared with the predicted results (the ones predicted by the software, if there is an option to check them)
 

FrantzM

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A bit OT.

It can go to itd own thread if necessary

I have 3 subs .. I have a Denon AVR-X3400H which has only 2 subs output. I have the Audyssey App. How do I calibrate Audyssey for the 3 subs?
 

Dimifoot

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A bit OT.

It can go to itd own thread if necessary

I have 3 subs .. I have a Denon AVR-X3400H which has only 2 subs output. I have the Audyssey App. How do I calibrate Audyssey for the 3 subs?

Buy a minidsp, do a pre-calibration calibration ;) (Freq.resp-time alignement-phase etc) on the minidsp and have the Audyssey calibrate the three subs as one.
 

Dimifoot

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FrantzM

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Buy a minidsp, do a pre-calibration calibration ;) (Freq.resp-time alignement-phase etc) on the minidsp and have the Audyssey calibrate the three subs as one.

Thanks
I have a minDSP 2 x 4 and have calibrated the subs using REW... Now to have Audyssey see one sub. Great idea! Thanks again!
 

Dimifoot

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bobbooo

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The error is insignificant as long as you don't remove a wall between measurements or drive your speakers into distortion.



I would need to search through the thread just like you.

XT32 offers more filter taps so you get better resolution at lower frequencies where it is needed most.

It agree this is probably all true, but it would be nice if we had actual acoustic measurements to back it up. It's never a good idea to just assume technologies work exactly as manufacturers describe without proper measurements. ASR has shown these assumptions can be wrong in the past.
 
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bobbooo

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The Klippel won't be of any help when comparing Room Eq software predictions/results.

What's needed is a REW post calibration measurement, averaged from multiple positions in the Listening Area+Main Listening Position or using the Moving Microphone Method.

Its quite easy to set it up as a test, you only need time and the AVRs that are equipped with the software for comparison.

The results can also be compared with the predicted results (the ones predicted by the software, if there is an option to check them)

Yes this would be a good test (although the Klippel NFS would produce more precise results). Unfortunately I've never seen it done.
 
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markus

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It agree this is probably all true, but it would be nice if we had actual acoustic measurements to back it up. It's never a good idea to just assume technologies work exactly as manufacturers describe without proper measurements. ASR has shown these assumptions can be wrong in the past.

You're beating a dead horse. I did all those measurements years ago. It has all been posted on AVSforum.com
 

bobbooo

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You're beating a dead horse. I did all those measurements years ago. It has all been posted on AVSforum.com

Then would be kind enough to find and share your measurements? I'm sure many of us here would be very interested to see them.
 

markus

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Then would be kind enough to find and share your measurements? I'm sure many of us here would be very interested to see them.

I would need to restore from backup. This was years ago. If you don't believe my words then you have to do the same thing I did back then, buy different AVRs and measuring gear then learn how to do measurements.

The short answer to your question regarding XT vs. XT32 is: don't bother with anything below XT32. The filter resolution isn't good enough for correcting low frequency issues. This is caused by the filter bins having the same width. Our hearing operates more along a logarithmic scale though. So you get high resolution where it doesn't matter (at high frequencies) but low resolution at low frequencies where the opposite is needed. In XT32 Audyssey applied some clever transformation that results in narrow bins at low frequencies and wider bins at high frequencies. Exactly how it should have been right from the start.

In any case all this becomes moot when Dirac finally gets their bass management solution out of the door. It will be a significant improvement over anything Audyssey can do.
 
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LumbermanSVO

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Sure, but Oppo BluRay players, aside from being renowned as high quality with excellent engineering, also provided discrete outputs for surround channels and decoded surround formats, which makes them basically prepros as well.

It's a shame they discontinued the 200 series so quickly. Either one would have worked perfect for me, and I could ditch my Marantz space heater. The ebay prices for the 203 are all over the map, and the 205 significantly higher.
 

No. 5

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The Klippel won't be of any help when comparing Room Eq software predictions/results.
What about for the direct sound? If a Room EQ system is applying filters above bass frequencies, the Room EQ system becomes a Speaker EQ system and the quality of the direct sound will be affected and in room measurements will not clearly show that effect. Of course in that case, the crux of the matter is to know what filters are being applied and that can be found without re-measuring a speaker.
 

Dimifoot

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What about for the direct sound? If a Room EQ system is applying filters above bass frequencies, the Room EQ system becomes a Speaker EQ system and the quality of the direct sound will be affected and in room measurements will not clearly show that effect. Of course in that case, the crux of the matter is to know what filters are being applied and that can be found without re-measuring a speaker.

Thats a separate (interesting) discussion.
The question was how to compare Eq software, and also how to compare predicted and real outcomes of these softwares.
 

No. 5

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Thats a separate (interesting) discussion.
The question was how to compare Eq software, and also how to compare predicted and real outcomes of these softwares.
That's my fault for just skimming a thread. :)

But if that's the question, in room measurements are (as you said) certainly the way to go.
 

A/V Analysis

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Oppo didn't make AVR's. They made bluray players.
Sure, but Oppo BluRay players, aside from being renowned as high quality with excellent engineering, also provided discrete outputs for surround channels and decoded surround formats, which makes them basically prepros as well.
The Oppo UDPs also had 1-2 HDMI inputs, HDMI ARC support, full codec decoding and 7.1 volume control. While not the primary, advertised functionality, they can indeed be deployed as a surround processor (SSP).

https://www.oppodigital.com.au/blogs/reviews-resources/15420449-using-your-oppo-as-a-pre-amplifier

There are even modifications to bypass the DACs and output PCM via S/PDIF.
 
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