Topping DM7 8-Channel DAC Review

[dartinbout]

I was referring to the Shield's USB output mode

If you still had the Shield, I would recommend trying it. I had to use Samsung S8 tab to play MC content for a couple weeks. With a USB cable, music and video played perfectly mapped connected to the DM7. Foobar and VLC played everything. As I've asserted before, the DM7 is my dream device for content consumption.

 

[dreadknot]

Probably better off with an AV processor

can you give a detailed reason why

 

[galego100]

Hello to all ,

I have a Denon 4800x , i have 5 monos from Fosi, the V3 model ones... If i buy the DM7 and join the monos, i will achieve better sound for movies than the Denon ?
I use coreelec.

 

[staticV3]

Hello to all ,

I have a Denon 4800x , i have 5 monos from Fosi, the V3 model ones... If i buy the DM7 and join the monos, i will achieve better sound for movies than the Denon ?
I use coreelec.

With the DM7 you will lose MCH decoding and room correction/loudspeaker calibration capabilities.

Unless you can substitute these with some other software, sound quality will likely suffer.

With a miniDSP HT or HTx, you could at least keep room correction and loudspeaker calibration.

Still, you would not be able to decode DTS or Atmos.

 

[Magicmastja]

I find it simultaneously comical, frustrating, and endearing just how many different pockets of the audiophile and general A/V community are trying to find a path to enjoy TrueHD + Atmos content without being forced into using a sanctioned big-box store Arc/eArc receiver somewhere in the signal chain. If anything im surprised that I havnt seen someone extract the codec binaries from a rooted smart TV or decompiled receiver ROM and float those out quietly on the clearnet for folks to pull apart and repack into usable Win/Linux packages, or it already has and its managing to remain walled-gardened/DMCA-ed off the net for now. Guess the DRM techniques in use are just that good or the compiled software is so specialized/non-standard that its an especially non-trivial task to work with it inside of Ghidra or similar.

So much of this annoyance would be alleviated if Smart TV manufacturers were either willing or allowed to just run the codec internally and output multi-channel PCM to one of the included USB ports, navigating the audio driver compatibility conundrum being the hardest part of that I suppose without allowing the user too much system access to become a security risk. Im sure someone(s) will figure it out eventually, it is kind of absurd to have to fork over $200-1000+ (depending on unit, used or new) for giant AV receiver to function only as an oversized file-format converter.

 

[MWC]

I find it simultaneously comical, frustrating, and endearing just how many different pockets of the audiophile and general A/V community are trying to find a path to enjoy TrueHD + Atmos content without being forced into using a sanctioned big-box store Arc/eArc receiver somewhere in the signal chain. If anything im surprised that I havnt seen someone extract the codec binaries from a rooted smart TV or decompiled receiver ROM and float those out quietly on the clearnet for folks to pull apart and repack into usable Win/Linux packages, or it already has and its managing to remain walled-gardened/DMCA-ed off the net for now. Guess the DRM techniques in use are just that good or the compiled software is so specialized/non-standard that its an especially non-trivial task to work with it inside of Ghidra or similar.

So much of this annoyance would be alleviated if Smart TV manufacturers were either willing or allowed to just run the codec internally and output multi-channel PCM to one of the included USB ports, navigating the audio driver compatibility conundrum being the hardest part of that I suppose without allowing the user too much system access to become a security risk. Im sure someone(s) will figure it out eventually, it is kind of absurd to have to fork over $200-1000+ (depending on unit, used or new) for giant AV receiver to function only as an oversized file-format converter.

I enjoyed reading your well-written rant. May I point out that Windows can natively decode Atmos using it's built in Movies+TV app, possibly also Media Player, which latter I usually avoid.

 

[Magicmastja]

I enjoyed reading your well-written rant. May I point out that Windows can natively decode Atmos using it's built in Movies+TV app, possibly also Media Player, which latter I usually avoid.

Haha thanks, I was a writer first growing up before I landed on the dev path. Yeah it appears the Movies+TV app, at least just skimming user feedback on it compatibility, seems to fall into the same hole as every other stop-gap solution ive seen thus far: If you want Atmos, probably gonna have to settle for EAC3, if you want TrueHD, probably not getting Atmos. Assuming I am understanding the current market offerings for Dolby object-data + audio playback codecs correctly. The super janky Dolby-Reference-Player + Music Media Helper MLP to WAV is as close of a solution ive seen us get, but is of course both tedious and does not function as an in-flight live processing method.

Just taking a few shots in the dark, but im guessing Dolby's TrueHD+Atmos licensing terms must either specifically restrict outbound data streams solely to the HDMI interface or perhaps demand that all hardware implementations feed audio streams exclusively into a DSP+DAC after decoding has taken place, with no allowance for transcoding into different digital formats be made externally accessible.

We have a handful of enthusiast/power user ARM-SoC based Dolby streamer devices out in the wild now and the only reasons I can think of for them to not give users non-eArc based access to the audio output are the ones ive listed above or Dolby makes the legal consequences pretty explicit if your hardware device is found to be chip in the armor that lead to their IP spreading wildly and freely across the web. All of this is some fun/curious speculation on my part though, it could be the the simple fact that Dolbys fee structure is so brutal that the 1-2 dozen companies that can actually afford it simply dont want to spend resources supporting the niche use-case of circumventing a traditional AV receiver in favor of working with the handful 8+ channel USB DACs in active production.

 

[octupole]

Hello all first post.

I'm a DM7 owner. I haven't made much use of it. I bought a minidsp flex balanced as well mainly because I can trust it to be an active crossover all the time whether its plugged into my pc or not. I get that you can add protective elements to protect tweeters but right or wrong I'm just in the camp of trying not to add more things to the signal chain. Also, it would be great to have the more than a two way crossover.

First I tried to read through this whole thread. My question is simple. Can I trust Equalizer APO to not blow my tweeters? A simple yes or no will suffice if there is a clear answer. To me there just seems that there are a lot of variables with updates and software which does the unexpected. If I felt a little more confident I might try to learn how to make it all work.

I do have another use for the DM7 but that is for another post and is overkill for the application outside of just some confidence from interference of many different wires running everywhere.

Thanks for any help.

 

[staticV3]

Hello all first post.

I'm a DM7 owner. I haven't made much use of it. I bought a minidsp flex balanced as well mainly because I can trust it to be an active crossover all the time whether its plugged into my pc or not. I get that you can add protective elements to protect tweeters but right or wrong I'm just in the camp of trying not to add more things to the signal chain. Also, it would be great to have the more than a two way crossover.

First I tried to read through this whole thread. My question is simple. Can I trust Equalizer APO to not blow my tweeters? A simple yes or no will suffice if there is a clear answer. To me there just seems that there are a lot of variables with updates and software which does the unexpected. If I felt a little more confident I might try to learn how to make it all work.

I do have another use for the DM7 but that is for another post and is overkill for the application outside of just some confidence from interference of many different wires running everywhere.

Thanks for any help.

Hi @octupole! Welcome to ASR.

When used with USB DACs, EQApo has been rock-solid for me.

Still, as a 2nd line of defense, have you considered putting a passive attenuator like the Behringer Monitor1 between DM7 and Tweeter Amp?

Or, if your Amp has a volume knob built-in, you could use that to limit the maximum volume.

That way, you could set up EQApo so that even 100% volume out of your DM7, would not endanger your tweeters.

Alternatively, you could invest in an Amp with gain low enough to make blowing the tweeters impossible from the get-go.

 

[edechamps]

Can I trust Equalizer APO to not blow my tweeters?

Why would Equalizer APO blow your speakers? Equalizer APO is not magic; it can't send a signal that a normal app can't already send. If a signal can blow your tweeter, then any app can send that signal, and so can Equalizer APO. It's not special in that regard.

 

[staticV3]

Why would Equalizer APO blow your speakers? Equalizer APO is not magic; it can't send a signal that a normal app can't already send. If a signal can blow your tweeter, then any app can send that signal, and so can Equalizer APO. It's not special in that regard.

@octupole is worried that a bug in Equalizer APO may reset their config, resulting in higher than intended output from the DM7.

Hence them asking about other members' experience WRT stability.

This is perfectly reasonable IMO.

 

[boxerfan88]

First I tried to read through this whole thread. My question is simple. Can I trust Equalizer APO to not blow my tweeters? A simple yes or no will suffice if there is a clear answer. To me there just seems that there are a lot of variables with updates and software which does the unexpected. If I felt a little more confident I might try to learn how to make it all work.

First thing to consider- can your tweeter/tweeter_amp take DM7’s 0dBFS output in the HF range without blowing up?

If yes, then you’re probably safe.

If no, then you can use either DM7 volume control to reduce gain, or limit gain at the tweeter amplifier side.

I set my DM7 to -3dB volume as “insurance”, meanwhile my main volume control is done by foobar. I had a couple of occasions unknowingly/accidentally play full scale via foobar, it was terribly loud, and my speakers survived

From my experience owning DM7 and using it daily, I have not encountered DM7 forgetting it’s set volume of -3dB, even if I power off/cycle the device; or unplug/replug usb; or host PC sleep/unsleep/reboot.

 

[Sokel]

Hi @octupole! Welcome to ASR.

When used with USB DACs, EQApo has been rock-solid for me.

Still, as a 2nd line of defense, have you considered putting a passive attenuator like the Behringer Monitor1 between DM7 and Tweeter Amp?

Or, if your Amp has a volume knob built-in, you could use that to limit the maximum volume.

That way, you could set up EQApo so that even 100% volume out of your DM7, would not endanger your tweeters.

Alternatively, you could invest in an Amp with gain low enough to make blowing the tweeters impossible from the get-go.

Paranoid me wouldn't even use a rock-solid analog VC with a strong amp hooked straight to a tweeter without a cap,let alone digital VC.
If only I could show you messages "you were right" about this thing.

It's NOT specifically about EQApo app which is really nice or any other app or device using analog (or more dangerously) digital VC,it's about peace of mind.

 

[jeffaegrim]

In theory, yes.

In practice, the channel mapping will be a bit of hack because you'll have to lie to Windows and tell it you have a 5.1 device, otherwise you won't be able to output 4 channels from an APO. This means applications will believe you have a 5.1 output, and might try to output 5.1 audio, even though you only have stereo. This might lead to sub-optimal results and force you to downmix in Equalizer APO first.

Wow, thanks, glad I found your post - that blows. @juliangst mentioned pretty much the same thing. Does that mean that I can’t output simple stereo in 2.2 (mapped in EQ APO or something) like I can from my flex? & that 5.2 also doesn’t work, and neither does 5.3? Wtf, what are all these channels for if not for me to freely designate

How do you guys with multiple subs (2+) even manage home cinema and stereo in one set-up if the source is a PC? I guess I’m back to where I always thought I’d have to go - getting an AVR with XLR L/R pre outs and routing them into a flex. This way one can use the stereo as a standalone usb fed system and additionally turn on the AVR for movies while switching inputs and profiles on the flex. I guess the new Htx would also work if I’m understanding everything correctly?

i just want to find a way to seamlessly go from my stereo + subs to HC + subs and I thought this would be easier, considering I only have one digital source (a pc connected to the TV and the system)… what’s the go-to here?

Inb4 get one AVR and sell everything else

I don’t want to

 

[Magicmastja]

Wow, thanks, glad I found your post - that blows. @juliangst mentioned pretty much the same thing. Does that mean that I can’t output simple stereo in 2.2 (mapped in EQ APO or something) like I can from my flex? & that 5.2 also doesn’t work, and neither does 5.3? Wtf, what are all these channels for if not for me to freely designate

How do you guys with multiple subs (2+) even manage home cinema and stereo in one set-up if the source is a PC? I guess I’m back to where I always thought I’d have to go - getting an AVR with XLR pre outs and routing them into a flex. This way one can use the stereo as a standalone usb fed system and additionally turn on the AVR for movies while switching inputs and profiles on the flex. I guess the new Htx would also work if I’m understanding everything correctly?

i just want to find a way to seamlessly go from my stereo + subs to HC + subs and I thought this would be easier, considering I only have one digital source (a pc connected to the TV and the system)… what’s the go-to here?

Inb4 get one AVR and sell everything else

I don’t want to

Before you conclude your personal journey through the 5 Stages of Grief - Home Theater Edition as many of us before you have, if your defiance of propriety standards and hatred of self are strong enough you can embark on the journey to learn the forbidden art of soldering to modify the absolute dirt cheapest AVR that meets your minimum DTS/Atmos decoding standard requirements. The fellow in that forum thread made a video documenting his process as well.

Not what you were asking for of course but yeah man, it sucks. Usually all it takes to get around problems like this is an dev/engineer with sufficiently high levels of spite and free time to find an exploit but these AVR SHARC processors have somehow managed to keep prying eyes at bay for about a decade at this point. Either that or this endeavor is just niche enough to avoid stirring up a massive reverse engineering coalition similar to what descends upon every new gaming home console release, as those are successfully rooted within seemingly a matter of months post-launch these days lol

 

[jeffaegrim]

Before you conclude your personal journey through the 5 Stages of Grief - Home Theater Edition as many of us before you have, if your defiance of propriety standards and hatred of self are strong enough you can embark on the journey to learn the forbidden art of soldering to modify the absolute dirt cheapest AVR that meets your minimum DTS/Atmos decoding standard requirements. The fellow in that forum thread made a video documenting his process as well.

Not what you were asking for of course but yeah man, it sucks. Usually all it takes to get around problems like this is an dev/engineer with sufficiently high levels of spite and free time to find an exploit but these AVR SHARC processors have somehow managed to keep prying eyes at bay for about a decade at this point. Either that or this endeavor is just niche enough to avoid stirring up a massive reverse engineering coalition similar to what descends upon every new gaming home console release, as those are successfully rooted within seemingly a matter of months post-launch these days lol

Thank you very much for the link and the interesting suggestion, I’ll give the thread a read and perhaps I might be persuaded otherwise, but my initial reaction to the idea of modifying an AVR was to laugh, because at the outset I omitted mentioning that I feel pretty incompetent when it comes to these things - but nonetheless willing to learn!

You’re absolutely right, too, it’s really annoying and very unintuitive if you’re trying to avoid a one-AVR-solution. And even then I can think of ways I could still be limited. Let’s hope they don’t make the endeavour impossible in the future, anyway

 

[MWC]

Before you conclude your personal journey through the 5 Stages of Grief - Home Theater Edition as many of us before you have, if your defiance of propriety standards and hatred of self are strong enough you can embark on the journey to learn the forbidden art of soldering to modify the absolute dirt cheapest AVR that meets your minimum DTS/Atmos decoding standard requirements. The fellow in that forum thread made a video documenting his process as well.

Not what you were asking for of course but yeah man, it sucks. Usually all it takes to get around problems like this is an dev/engineer with sufficiently high levels of spite and free time to find an exploit but these AVR SHARC processors have somehow managed to keep prying eyes at bay for about a decade at this point. Either that or this endeavor is just niche enough to avoid stirring up a massive reverse engineering coalition similar to what descends upon every new gaming home console release, as those are successfully rooted within seemingly a matter of months post-launch these days lol

The audio on that video is so obnoxious I don't want to watch it, no matter how interesting the content is! Why on earth would anyone want to process their voice to sound so unrealistic & horrible? Does he think Darth Veda's voice is attractive?

 

[edechamps]

@octupole is worried that a bug in Equalizer APO may reset their config, resulting in higher than intended output from the DM7.

Ah, so they're relying on Equalizer APO to attenuate the signal to safe levels? In that case yes, that's indeed a valid concern. Equalizer APO is very much a "best effort" kind of thing and there are various ways it can get accidentally disabled. For example, driver updates and/or Windows updates will sometimes reset the device to use the original APO, and Windows may automatically disable an APO if it thinks it's misbehaving (e.g. crashing). I would definitely not rely on an APO with any kind of guarantee that it will always be enabled.

 

[richardm]

Ah, so they're relying on Equalizer APO to attenuate the signal to safe levels? In that case yes, that's indeed a valid concern. Equalizer APO is very much a "best effort" kind of thing and there are various ways it can get accidentally disabled. For example, driver updates and/or Windows updates will sometimes reset the device to use the original APO, and Windows may automatically disable an APO if it thinks it's misbehaving (e.g. crashing). I would definitely not rely on an APO with any kind of guarantee that it will always be enabled.

On several occasions I've fired up my PC, started playing music, and found EqAPO lacking a "binding" to the currently active active device in Windows. I have two GPU's (each with 3x DP and 1x HDMI) and motherboard video (one more HDMI). So I have a bucketload of audio ports. I've found the "mappings" between the audio device in Windows and the physical port are not always stable. Driver updates, changing BIOS settings, anything that alters which display card Windows sees as "primary" and therefore places the logon screen, etc etc.

I'm only using EqAPO for sub/main xover so the consequences aren't as great. But if I'd been using EqAPO for woofer/tweeter xover with no protection cap I'd have killed 3-4 tweeters by now.

 

[meooms]

On several occasions I've fired up my PC, started playing music, and found EqAPO lacking a "binding" to the currently active active device in Windows. I have two GPU's (each with 3x DP and 1x HDMI) and motherboard video (one more HDMI). So I have a bucketload of audio ports. I've found the "mappings" between the audio device in Windows and the physical port are not always stable. Driver updates, changing BIOS settings, anything that alters which display card Windows sees as "primary" and therefore places the logon screen, etc etc.

I'm only using EqAPO for sub/main xover so the consequences aren't as great. But if I'd been using EqAPO for woofer/tweeter xover with no protection cap I'd have killed 3-4 tweeters by now.

I agree. I use a 30uF cap on my ribbon tweeter to protect it against mishaps in the software Xover. This has saved the tweeters multiple times (mainly user error).