NAD M33 Streaming Amplifier Review

[Vasr]

I move the curtain far left so only correcting 30 to 200 hz everything sounds flat. Life less and no sound stage. Even when I don't apply correction above 200hz my max volume is cut by 20db.

The volume attenuation isn't based on how wide the correction spectrum is but on the max boost provided within the correction spectrum.

However, that 20db attenuation seems too high even for Dirac. So, if multiple people are facing some coloration as well. Perhaps there is a bug in the implementation when a limited correction window is used.

This is not a bug in Dirac Live measurement and filter generation since the same software is used for all Dirac enabled devices but in the Dirac processing implemented on the NAD.

 

[fcracer]

I understand what pogo explaining. My issue is also this.
If I select any curve. Harmon or nad
I move the curtain far left so only correcting 30 to 200 hz everything sounds flat. Life less and no sound stage. Even when I don't apply correction above 200hz my max volume is cut by 20db. All I want to do is correct below 200hz but dirac muddied the sound.
I'm trying to learn how to take before and after measurements using rew.
I do know that DL works great on my c658. There is no loss of volume and I can specify correction in the < 200hz range.
Both the m33 and c658 are using my magnipan LRS speakers. So my previous question regarding dipole speakers are not needed.
Now I can't get DL 3.0.13 to run even after using it for days before. Same computer and deleting and new install. Crashes after first measurement. Had to revert to earlier version.

In a previous post, DJ had shared your measurements in DL. The sub level looks very low. It would make sense for DL to attenuate the volume of the mains to match the level of the sub because it would require massive power to try and boost the volume of the sub to match the main speakers.

In regards to DL crashing, I too get crashing from time to time but it’s always when exporting a filter to the M33. It actually does export but crashes immediately after the export. For the problems you’re having, have you tried resetting the M33, or reaching out to NAD and Dirac to get their help?

 

[pogo]

I understand what pogo explaining. My issue is also this.
If I select any curve. Harmon or nad
I move the curtain far left so only correcting 30 to 200 hz everything sounds flat. Life less and no sound stage. Even when I don't apply correction above 200hz my max volume is cut by 20db. All I want to do is correct below 200hz but dirac muddied the sound.
I'm trying to learn how to take before and after measurements using rew.
I do know that DL works great on my c658. There is no loss of volume and I can specify correction in the < 200hz range.
Both the m33 and c658 are using my magnipan LRS speakers. So my previous question regarding dipole speakers are not needed.
Now I can't get DL 3.0.13 to run even after using it for days before. Same computer and deleting and new install. Crashes after first measurement. Had to revert to earlier version.

Does that mean that your C658 sounds better to you with DL correction than the M33 without DL (soundstage, ...)?
The background to my question is where to look for the bottleneck.

 

[Jbeck]

Does that mean that your C658 sounds better to you with DL correction than the M33 without DL (soundstage, ...)?
The background to my question is where to look for the bottleneck.

It sounds much better without DL correction.
I did learn how to use REW last night. With rew I was able to set phase and levels of the sub. I was able to produce a surprising flat response at 80 hz. I then produced a new DL measurement. I then made several filters. Two with harmon 8db sub boost and a couple with no correction after 200hz and 100hz.
I saved a measurement with Rew with no correction. Today I will use REW to compare results of the different filters.

 

[NOLA_Sound11]

Hi Craig, as fellow 390DD owner contemplating upgrading to the M33, I thought you’d be interested in knowing the market for the 390DD. I placed mine online for sale here in Asia and it sold within a week!

I bought the 390DD and BluOS MDC for the equivalent of US$2,229 in 2015. I sold it for US$1,160. I’m rather pleased with its resale value. The little grey box cost only US$180/yr in depreciation. Most importantly, the buyer is super happy with the purchase.

Wow! Thanks for the info. That's encouraging. It's such a great piece of gear that I may keep it around and hand down to my daughter after she finishes university studies. She's a budding young audiophile of sorts! But good to know it's maintained it's value.

 

[Jbeck]

Maybe I'm not using rew correctly but using rew to measure response after applying correction i see no difference in frequency changes. Even when I move the correction windows. I made a measurement with DL off using rew. Then I made a measurement with rew with DLon and the nad curve. The most pronounced change was a shift across the entire bandwidth of 10db.
The other observation was if I restricted correction to below 70hz the entire bandwidth still shifted . I would assume that everything outside of my requested correction would remain as before but sadly DL ignores the limits I place and rolls off every frequency thus reducing output by as much as 15db. I will attach some photos of rew a bit later today.

 

[fcracer]

Maybe I'm not using rew correctly but using rew to measure response after applying correction i see no difference in frequency changes. Even when I move the correction windows. I made a measurement with DL off using rew. Then I made a measurement with rew with DLon and the nad curve. The most pronounced change was a shift across the entire bandwidth of 10db.
The other observation was if I restricted correction to below 70hz the entire bandwidth still shifted . I would assume that everything outside of my requested correction would remain as before but sadly DL ignores the limits I place and rolls off every frequency thus reducing output by as much as 15db. I will attach some photos of rew a bit later today.

Hi Jbeck,

Not sure if this helps in any way, but I took a before and after REW with Dirac on my M33. I don't see any reduction in db. This is with Dirac LE windowed at 30Hz and 500Hz. It doesn't look like Dirac is boosting any frequencies in my setup so that may be the reason why it isn't setting aside additional headroom. In your setup, it may be trying to boost frequencies and requires the additional headroom.

Have you tried a full reset of the M33 to factory settings and starting from scratch? I had a strange issue with my C390DD in the past and only a full HARD reset solved the issue; might be worth a shot.

To do a soft reset on the M33:

• Go to Settings - Other menu option and select Factory Reset to initiate restoring of the M33 to factory default settings. Follow the prompt commands.

To do a hard reset on the M33:

1. Press and hold rear panel RESET tact switch and while doing so, turn ON the rear panel POWER switch. Do not release hold of the RESET tact switch.
2. Hold down the RESET tact switch - STATUS INDICATOR (NAD logo) alternately blinks red and white.
3. Release the RESET tact switch as soon as the front panel display shows “Factory Reset...”
4. Successful Factory Reset is indicated by the unit rebooting.

- For wireless connection, M33 returns to Hotspot mode and STATUS INDICATOR (NAD logo) indicator turns into solid white.
- For wired connection, M33 will simply connect as if it was a new player and NAD logo indicator turns into solid white.

 

[Jbeck]

I received a text from Nad. They said that they did in fact see an issue with dirac live and BluOs on the m33. So now I can stop searching for solutions. But....... now my screen has blown out around the edges and I have clicking and popping . Not a smart purchase. Now after all this my screen is blown out

 

[Jbeck]

Has anyone had to get these repaired? I bet parts are unavailable

 

[watchnerd]

Has anyone had to get these repaired? I bet parts are unavailable

It's so new, shouldn't it be under warranty?

I can't see why any user would be doing self repair.

 

[pogo]

I received a text from Nad. They said that they did in fact see an issue with dirac live and BluOs on the m33. So now I can stop searching for solutions. But....... now my screen has blown out around the edges and I have clicking and popping . Not a smart purchase. Now after all this my screen is blown out

That's exactly what i said in my post # 297 including my containment for the M33

 

[Jbeck]

It's so new, shouldn't it be under warranty?

I can't see why any user would be doing self repair.

Who said anything about self repair? I asked if any one had to get service on the m33. There is so many things wrong with this I don't think I will get the same unit back and I had to wait several months for this one. No parts. I really don't see where you got the idea I wanted to fix it myself

 

[watchnerd]

Who said anything about self repair? I asked if any one had to get service on the m33. There is so many things wrong with this I don't think I will get the same unit back and I had to wait several months for this one. No parts. I really don't see where you got the idea I wanted to fix it myself

Because asking about parts availability isn't a question one normally asks a bunch of random internet people for an item under warranty repair -- that's a question for NAD.

 

[Chippyboy]

Because asking about parts availability isn't a question one normally asks a bunch of random internet people for an item under warranty repair -- that's a question for NAD.

I'm with Jbeck. Nothing he said even vaguely hinted at self repair IMO. He was simply questioning whether a return to vendor for repair might take ages due to unavailability of spare parts. A reasonable speculation given the current supply issues affecting all sorts of hifi. FWIW I've had a pair of Revel speakers on order for over a month.

 

[watchnerd]

I'm with Jbeck. Nothing he said even vaguely hinted at self repair IMO. He was simply questioning whether a return to vendor for repair might take ages due to unavailability of spare parts. A reasonable speculation given the current supply issues affecting all sorts of hifi. FWIW I've had a pair of Revel speakers on order for over a month.

Okay.

Your brain works differently than mine.

 

[Jbeck]

Okay.

Your brain works differently than mine.

I can see how you came to that conclusion. No problem its all good

 

[pogo]

I received a text from Nad. They said that they did in fact see an issue with dirac live and BluOs on the m33.

Have you tried to use your C658 as preamplifier for the M33 and started a DL measurement on the C658?
It could be that the measuring microphone or the DL algorithms are the bottleneck in combination with the purifis, which play very fast and squeaky clean. This test could give an indication.
Background:
According to my reading impressions, the phenomenon only occurs with high-quality speakers and the M33 (Purifi). That's why I suspect the measuring microphone or the DL algorithms as i mentioned before in post #287.

 

[Jbeck]

Have you tried to use your C658 as preamplifier for the M33 and started a DL measurement on the C658?
It could be that the measuring microphone or the DL algorithms are the bottleneck in combination with the purifis, which play very fast and squeaky clean. This test could give an indication.
Background:
According to my reading impressions, the phenomenon only occurs with high-quality speakers and the M33 (Purifi). That's why I suspect the measuring microphone or the DL algorithms as i mentioned before in post #287.

Yes thats just what I did. My c658 was connected to a high quality amp with the same magnipan speakers. I made 5 filters using the same microphone "umk something" sound was great. No loss of base and no reduction of headroom.
As a test I connected my c658 as a pre/ processor to the m33 amps to the exact same magnipan speakers. Sound was actually much better . No loss of headroom and a much better soundstage. I attribute that to the purfi amps. So comparing dirac live between the two pre amps results in a major difference. Something with the nad m33 is not working with dirac well.

I'm going to research if I can somehow copy the filters from the c658 and transfer to the m33. Is that possible?

I have a restored commitment to get the m33 to preform as well as the c658 now.
Lenbrook has offered to buy back my m33 or swap for a new one because of the wonky screen that intermittent goes out or get full credit towards a pair of c298 with the purify amps. I really love the crystal clean power and controlled bass that the purfi amps produce. They are a perfect match for my 4 ohm power sucking magnipan speakers. Magnipan are known for their 3d sound and soundstage. With the Purifi amps i get that and excellent dynamics at higher volumes. I get no fatigue listening at much higher volume especially with music recorded live in small pubs.

 

[Jbeck]

The same lifeless and cloudy sound result with Harman or NAD curves. It has nothing to do with whether certain frequency ranges are reproduced louder or quieter!

Since DL tries to correct the impulse response and not just the frequency response, I have made the following measurements in the past:


View attachment 109135

These clearly show that the impulse response is corrected even above the desired correction range of 50-200Hz, in my case it is worsened.


I was able to suppress the impulse response correction using my self-generated flat curve with a quasi-optimal impulse response. The result (correction range of 50-100Hz) is light years better (no lifeless and cloudy sound) and no change above 100Hz can be seen!:
Pogo.. can you explain how you went about generating your flat curve and how you went about measuring for impulse response. I want to duplicate your findings
View attachment 109136

 

[Jbeck]

Pogo.. can you explain how you went about generating your flat curve and how you went about measuring for impulse response. I want to duplicate your findings
View attachment 109136