NAD T758 V3 AVR Receiver Owner's Thread

[ceh383]

I was using a receiver with NanoAVR-DL for multi-channel music and PC based Dirac for 2 Channel, so signal path for both is:
Source => Dirac Filters => BM => Speakers

With the T758 it's:
Source => BM => Dirac Filters => Speakers (which is the way it's supposed to be according to dirac)

This is interesting, although with the DDRC88, I'm not sure how much it matters. While it is true the mixing is after the DL filters, all the XO's/routing are/is done before the filters and all subs are filtered as one.
I would like to see some graphs comparing the two methods of implementing DL.
I'd like to simplify my system, but I'm just not sold yet.

 

[bkeeler10]

T758v3 arrived Wednesday . . .

There is a very noticeable hiss coming from the height channel speakers when connected to the 4 RCA jacks on the MDC board.

Thanks for your initial thoughts. This hissing is what I've read about elsewhere, and the only significant concern I have with this unit. Sonnie, I guess you haven't had a problem with this . . .

 

[JStewart]

I can't say I'm noticing any difference in the bass between DL in the DDRC and 758. It could be that your response is somehow smoother, or the bass levels may be a little different. About the only way to know I think would be to measure with REW, as the DL processing should be the same between the two units.

Spot on Sonnie. Bass response different. Some of the kick was gone from the kick drum. Had the effect of making it sound "tighter" or smoother.

I would like to see some graphs comparing the two methods of implementing DL.

Then graphs you shall have.









Added filter below to deal with the slight dip at 65hz.


Bingo. Mic got moved slightly so disregard anything above 350-400 or so on the blue line.


There are clearly some differences. At this point I assume intentional vs a "defect" in either the Dirac Stereo Tool or Dirac for NAD tool. No way for me to test.

The NAD version did leave a small dip at 65hz (IN MY SETUP) that was easily removed. As for the delta between target and result for the two tools, subjectively with these results, the NAD has a more "natural and open" presentation while still seeming to maintain the pinpoint imaging, where the Stereo version, if the mic locations aren't spaced over a 5 to 6 ft area, can sound a bit "over processed". To me neither sounds "better" than the other. Just slightly different.

This hissing is what I've read about elsewhere, and the only significant concern I have with this unit. Sonnie

I'd read the same. Super happy the way the problem is being handled though. No 2nd guessing (which I hope turns out not to be a mistake on their part!). Yesterday I saw that they had shipped the replacement already. And I'm listening to the one to be sent back as I write this. So they are pretty trusting as well. I've never done business with them before.

 

[Sonnie]

No hissing that I've noticed.

Hmmm... it doesn't even look like DL is doing much on your response above 100Hz... the PC version looks like a much better response.

 

[JStewart]

Hmmm... it doesn't even look like DL is doing much on your response above 100Hz... the PC version looks like a much better response.

MiniDSP 2x4HD below 100hz. 3 subs. Eq'd with MSO. Not sure DL has much to do in that region. What I think I see is the overall response follows the DL target. There's just more deviation around the NAD target vs. PC DL target.

Question is is this expected behavior or not? Is @AudiocRaver still doing an evaluation of this unit? I'll bet he could shed some light. Or perhaps @Flak might have some insight?

What was the smoothing you used for the graph you posted at the beginning of this thread? I might change mine to match if needed and scale the Y axis the same to compare.

 

[ceh383]

Looking at the average spectrum before on the stereo vs the NAD, it looks like much better native response in the stereo graph, and DL had less to do.
Are these the same speakers, placement and room?

 

[JStewart]

The speaker and sub locations were unchanged.

The average spectrum is different because with DL for pc stereo the crossovers come after the DL's calibration signal and calibration filters, i.e. The crossovers were active during the calibration.

In the case of DL for NAD the crossovers are bypassed and each speaker is calibrated as if it were set to Large in the NAD. After the calibration the crossovers can be set to suit the needs. Needless to say with a small room the fronts need help from subs.

You make a good point with respect to working harder and it could be.

My own theory is its design intent. I'm leaning that way because the variance from target is more prounounced accross the entire response.

I feel like I need to say again that subjectively the differences are there but not affecting imaging that i can tell. It still sounds like I'd expect Dirac to sound, which is very good.

 

[ceh383]

My own theory is its design intent. I'm leaning that way because the variance from target is more prounounced accross the entire response.

I think no and yes. I don't believe it is a design intent, but yes the variance from target is more pronounced. I was looking above 100hz, as was Sonnie. DL, can only boost 10db, at least with the 88a. If you look closely you will see why the greater variance from the target is there. I would bet it has to do with mic placement during the calibration.
Based on the graphs I'm sure it sounds very good.

 

[JStewart]

I would bet it has to do with mic placement during the calibration

Well at least I can rule that out. The mic did not move during either calibration and stayed untouched in that same spot for the red (DL for PC) and green (DL for NAD) REW measurements. The calibrations were a single point only at the MLP EDIT: REW was measuring the right front speaker.

10db max boost is true for DL for NAD, DL for PC, and MiniDSP NanoAVR-DL too.

 

[Sonnie]

It's hard to say what might be happening, but certainly it does not look right.

 

[JStewart]

It's hard to say what might be happening, but certainly it does not look right.

I don't disagree. I should have taken a minute to use REW for the full 9 point calibration but didn't. The unit is now packed up and on its way back due to the hissing sound from the height channels, but when its replacement arrives I will do that.

I did watch 3 movies 1 of which is my go to for checking changes. To my ears it sounded better than the calibration I have on the MiniDSP AVR-DL, and would attribute any differences to measurement positions. You're obviously happy with yours so I'm thinking this will turn out to be a non-issue and am not really concerned.

I did notice that the output from the RCA's for the height channel and the subwoofer RCA outputs seemed lower than the rest. I found info on another forum also that said they were down about 4db from the others. With the sub it still calibrated at -3 db on they NAD when I'm used to seeing -7 so no issue there, but for the height channels I'm using the yamaha RX-A2030 on the multichannel inputs as an amp. I turned the volume on it up enough to match the levels of the other outputs with an SPL meter. So what I'm wondering is if it's a gain structure problem with my set-up and not a defective unit. I guess I'll also find that out when the replacement NAD arrives.

The BluOS app takes a little getting used to. I was surprised that BluOS didn't see shared folders on my PC that other players like the yamaha receiver or Oppo BD103 could find and play. Turns out BluOS doesn't work with DNLA servers. In the end it worked fine but you have to find and follow the instructions to set up your file sharing on their website.

I then compared the sound quality between the streaming with the BluOS app and a direct connection to laptop via hdmi. The HDMI connection sounded better. My wireless connection is not the best and I think that's the issue. I've ordered a USB to ethernet adapter to try instead. The NAD was sitting right next to the router and that can cause problems with wireless reception. I had a similar issue with a ROKU unit on wireless near there and connecting to my switch via ethernet cable solved it.

Quick personal story. I was talking to my wife about the NAD which she unwittingly purchased for me for my 60th birthday this coming weekend. She patiently let me explain some of the features. When I got to part where I told her it does not have all the DSP programs like the Yamaha does and you pretty much just set up once and watch your movies she replied "Bless your heart, I'm sure you'll be fine with it." Now Sonnie, you're from the south so you know what she was saying. For anyone not from the south, bless your heart is code for dumb ... NAD has now met WAF criteria!

 

[Flak]

Apple&NAD 758 users may find this interesting:
https://itunes.apple.com/it/app/t-7...e&preserveScrollPosition=true#platform/iphone

 

[Eric SVL]

Glad to have found this thread. I want to try Dirac, but prior to this AVR, the only viable way was to get a miniDSP 88A unit and run from my Denon X4000 > 88A > Amp. The investment would probably be around $2k in the 88A and an amp. It's too bad I couldn't do the correction with the 88A, then run back into the AVR to use those amps. It's a shame they would just sit there going to waste.

So, a few questions I have, if you guys don't mind:

1. Can it calibrate dual subs properly? Any bass management issues? I currently use Audyssey XT32 + SubEQ and it does a fine job.
2. What would be the best way to emulate Dynamic EQ? Set multiple preset curves for different volume levels?
3. Why would someone get the 777 v3 over this?

 

[JStewart]

1. Can it calibrate dual subs properly? Any bass management issues?

It does not calibrate dual subs. There's a single sub out only. I have MiniDSP 2x4HD for 3 subs and use MSO to configure them. Dirac filters are then applied to the 3 together.
No bass mgmt issues. Bass mgmt and Dirac are integrated in the correct order per Dirac's recommendation.

2. What would be the best way to emulate Dynamic EQ? Set multiple preset curves for different volume levels?

I'm not familiar with audyssey dynamic EQ, but yes you can store 3 dirac preset curves.

3. Why would someone get the 777 v3 over this?

That's a tough one because you'd think given the price difference there'd be some compelling reason(s). The only meaningful difference I see is the number of HDMI inputs in the AVR.
I don't believe the difference in RMS wattage would result in much difference in SPL or headroom and if you needed it, for the same money you may do better with an external amp vs the 777.

If you've not tried Dirac you may be able to use Dirac's free trial of the PC/Mac version to see what you think.
https://www.dirac.com/online-store/

 

[Eric SVL]

Thanks. Dynamic EQ allows for a rise in bass and treble at low volumes, flattening out by the time you reach reference level. As the name implies, it is a dynamic curve based on output level. This is to account for the non-linearities in the human hearing system, as described by Fletcher and Munson. See: Fletcher Munson Curve.

Without it, lows and highs are relatively weaker at low volumes. In a nutshell, we are less sensitive to those frequencies, so we need greater SPL to hear them as equal, or balanced.

 

[Sonnie]

DEQ had an adverse effect on my center channel, so I was never able to use it... muffled the sound to a point of making it more difficult to understand dialog. It took be a while to figure out what was causing it, but finally... never missed it since I tuned my system to the volume I typically listen, and rarely would it go any lower than that volume.

As for multi subs... my two subs are located equal distance to my listening position, so having something like Sub-EQ is irrelevant... I run them in parallel. If your subs are not equal distance to your primary listening position, you can do the same thing that Audyssey does with Sub-EQ with the phase and volume controls on the sub closest to your primary listening position. Those are the only two settings that are different, as it equalizes the subs as one and not individually.

 

[JStewart]

NAD has solved the hiss/static and low output from the height channels on the AM230 MDC board with the new version of the AM230.
Received a new T758 with the new board this week and couldn't be happier. This was the 3rd replacement T758 since the original purchase. Much thanks to both David at Safe And Sound (safeandsoundhq.com) and Erik at NAD for working with me on this, never 2nd guessing, being very responsive, and with David it was always my option of how I wanted to proceed; refund, credit, or replacement unit. Superior customer service from both!!!

The low output from the height channels was the real culprit in my case. The efficiency of the base layer speakers is close to the efficiency of the height speakers so a Dirac calibration would reduce L/C/R pre-amp out by 3 to 4 db (to -3 and -4 db) and boost the heights to 4 to 6 db. This caused a noticeable loss in dynamics and some headroom. Trying to solve by boosting the height pre-amp out signals through turning up the outboard amp also boosted the noise floor resulting in hiss and in the case of one of the units, both hiss and static.
I think if you have or were to have a situation where the L/C/R speakers were 4 to 6 db lower in efficiency than the height speakers it may not matter or be noticed.

My issue with BueOs has also been resolved. Not a NAD issue but specific to my set-up and was due to proximity of wireless router broadcast and T758. Resolved with an ethernet connection as I suspected it might. If you would like to go this route use USB 2.0 to ethernet vs usb 3.0. Leave the wireless dongle in place in NAD's usb hub but don't provide the wireless connection a login/password. This adapter worked perfectly https://www.amazon.com/gp/product/B00MYT481C/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

A couple of FYIs. Dolby Vision pass through was implemented in a recent firmware upgrade. DTS X does not have an implementation date from NAD as far as i know. Until then no height channels with DTS sources.

Bottom line for me is super happy with the unit now. Working as it should and it's ticked off all the boxes I was looking for in an upgrade. (18gps hdmi, Dirac with correctly implemented bass management, eliminated using a laptop for hi-res music streaming with Dirac).

 

[Eric SVL]

DEQ had an adverse effect on my center channel, so I was never able to use it... muffled the sound to a point of making it more difficult to understand dialog. It took be a while to figure out what was causing it, but finally... never missed it since I tuned my system to the volume I typically listen, and rarely would it go any lower than that volume.

My volume does vary a bit so it's nice to have my bass still there when the system is played lower.

 

[Eric SVL]

This AVR has amps for 7 channels. I'm not buying another amp, so 7 it shall be. Here is how I'd like to use the 7 channels:

Front L/R (I don't use a center due to a large plasma screen - phantom is fine)
Surround L/R

That leaves me with 3 more speakers to place. I think the best option is to do 2 front heights, and 1 rear surround, the logic being that front heights can only be done in pairs and add more than rears, and with how small this room is, 2 rears wouldn't add much over one. However, can the AVR combine the signals to the two back surrounds into one?

I don't know that Emotiva will sell their surrounds as singles anyway, so I'm bound to have a wasted speaker. Regardless, how would you use the remaining 3 channels?

 

[Sonnie]

I'd personally do a center and two height speakers... even in a small room I never got anything meaningful from rear speakers. I just place my surrounds in the rear corners and it takes care of all of the rear. I prefer a more solid dialog. I've tried phantom and it's just not as clear to me. Most of the time it was accidental when stereo was left on after playing music and the Yamaha not auto setting back to surround. I would notice something odd about it and have to press Straight to fix it. Of course that is not an issue with the current NAD that I have now... it gets it right.

If you are fine with phantom center, then as you mentioned might work out okay for you.

 

[Eric SVL]

I'd personally do a center and two height speakers... even in a small room I never got anything meaningful from rear speakers. I just place my surrounds in the rear corners and it takes care of all of the rear. I prefer a more solid dialog. I've tried phantom and it's just not as clear to me. Most of the time it was accidental when stereo was left on after playing music and the Yamaha not auto setting back to surround. I would notice something odd about it and have to press Straight to fix it. Of course that is not an issue with the current NAD that I have now... it gets it right.

If you are fine with phantom center, then as you mentioned might work out okay for you.

Well as I mentioned there is no way to fit a matching center here with the 64" plasma, and even if I did have a space, it would be pretty much on the floor. The phantom provides the correct middle-of-screen height if you have speakers that image well.

The speakers I plan on using for surrounds are Airmotiv E2s, and maybe the E1s depending on the placement. I do have Airmotiv 5s (active) that are now without a purpose after being displaced by Mackie MR624s at my computer desk. Just to entertain the idea, what if I found a way to hang them as front heights, then the T758 could power Front L/R, Surround L/R. It might be more challenging to integrate and calibrate with Dirac a mix of passive and active speakers, but the AVR would still have 3 channels left it could power. Is there a limit on the number of channels Dirac can correct?

 

[JStewart]

Dirac will process all channels on T758. That is 7.1.4

 

[Eric SVL]

Dirac will process all channels on T758. That is 7.1.4

Good to know. I will see about using some active speakers to complete the setup, thus only needing the 7 channels of amplification from the T758 and no more. I already have a pair of Airmotiv 5s, and looking at the AVR, it looks like the one thing you can not power are Rear Height speakers - so that would be the place for them. I could then get a pair of Airmotiv B's (passive versions of the 5) for Front Heights. In this configuration, the Back Surrounds would be omitted, and I would move the Side Surrounds back a foot. Alternatively, I could power Back Surrounds, and go active for Front and Rear Heights. Please do let me know if you are aware of any limitations when assigning some channels to be active (pre-out) and others passive. I suspect not, since I assume many/most of you doing 7.1.4 are using these preouts to an amp:



So my choices are, Option 1:
Passive: Fronts (2), Surrounds (2), Front Heights (2)
Active: Rear Heights (2)

Option 2:
Passive: Fronts (2), Surrounds (2), Surround Backs (2)
Active: Rear Heights (2), Front Heights (2) (this would rely on being able to find another pair of used Airmotiv 5s, which isn't guaranteed)

Room is 17 x 10.5 x 8 with a single row of seats. What do you think?

 

[JStewart]

Eric SVL - You're correct that both option 1 and option 2 configurations are possible.

Please do let me know if you are aware of any limitations when assigning some channels to be active (pre-out) and others passive.

All channels have pre-amp out.
"Surround Back" built in amp can be re-assigned to Zone 2, Height 1, or Height 2. That's the only amp assignment that can be done.
Height 1 and Heigh2 can be designated as either Front, Middle, or Rear

 

[Eric SVL]

"Surround Back" built in amp can be re-assigned to Zone 2, Height 1, or Height 2. That's the only amp assignment that can be done.
Height 1 and Heigh2 can be designated as either Front, Middle, or Rear

That is good to know. Thanks!