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I replaced my AVR with a Flex HT, but don't recommend it.

Mort

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My holiday project and present to myself was to replace a Denon x4800h with a MiniDSP Flex HT system for 5.2 home theater. I had a blast doing this project and I’m sticking with the Flex HT. I like the MiniDSP tools much more and I like managing and tinkering with the system.

Should you replace your AVR with the HT Flex? Probably not. Although higher, it’s likely that the sonic/SINAD benefits are in the inaudible range. The Flex HT system probably more expensive, more complex, has more remotes, and lacks features compared to a good mid-range AVR. You are replacing one big box with several smaller boxes. MiniDSP accepts no returns and has no warranty.

Still interested? Here’s what I learned and did.

Despite being called a 'Multichannel Home Theater Processor', the Flex HT needs help to function as an AVR. The issue is that the Flex HT(x) system can only handle surround sound that is license-free, meaning it cannot decode any licensed compression formats like Dolby. To use the Flex HT as an AVR, licensed decoding must be done by a by another device (like an upstream video streamer) and then output in the unlicensed 'Uncompressed Multichannel LPCM' format via eARC to the Flex HT. (Uncompressed Multichannel LPCM can only be transmitted via eARC. )

In practice the above means the $600 HT requires two additional specialty devices (in addition to an external amplifier), raising the total cost another $400
  • A uncompressed multichannel LPCM video streaming source. Not much choice here. The ($149) Apple TV 4k video streamer is the only assured solution for Netflix, Hulu, Max etc... No other streamer works at the moment. Note that newer console gaming devices can also do uncompressed multichannel LPCM for many games and some better DVD/Bluray players also output uncompressed multichannel LPCM. It's just the video streamers that are behind although someone thinks the new Amazon Fire 4k might also work. Confusingly all TVs and streamers do 2 channels of uncompressed LPCM, which leads some people to think it will work multichannel, but it won't. Just get the Apple 4k.
  • An eARC splitter. This is a misunderstood and critical device. It doesn’t change the audio or do any decoding for the system. It’s just an active splitter (or switch) that splits the source HDMI (e.g. Apple TV 4k) into two: one 4k HDMI video to the TV display and one eARC HDMI audio to the Flex HT(x). HD Fury devices (cheapest is $249) are recommended but there are cheaper alternatives.
Setup and configuration

Once you have your devices, the routing is simple. Split the video source with your eARC splitter and route one cable to the TV and one to the Flex HT. Use good cables, eARC can be finicky.

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Some tips I can share
  • The Apple TV 4k remote can learn 'mute' and 'volume' from the Flex HT, but not ‘preset’ or ‘source’ so you are still likely to use two remotes plus your TV remote. Apparently the minidsp remote codes in the old Logitech Harmony system work if you have one.
  • The MiniDSP console software only runs on a computer, something I didn't have in my home theater room. At first, I used a very long cable so I could use a laptop comfortably away from thescreen. Later, I bought a used i3 minicomputer and connected to it with remote control software. That way I can connect to it on my phone as well.
  • Down/Up mixing yourself – I had to create a preset on the MiniDSP for up-mixing older 2ch video sources to have a center channel if the dialog isn’t clear enough in stereo. I also created a 5.1 upmix for 2ch games and live sports events.
  • If you need a video input switch, the HD Fury VRROOM can be purchased for $550 (used about $425) and it works well, but adds another remote and app.

 
Is that the only interface that uses that format?

Or the only format used on that interface?
Although I believe the first is true, I don't know the precise answer. Maybe someone else does.

For Flex HT purposes, it's the only solution.
 
Minidsp Flex HT cannot and will not replace an AVR.
It is not meant for that.
In some circumstances (niche applications), it allows to remove an AVR from an AV stack.
Which was my case but was a very specific use case.
I had a mixed music and HT environment:
- HT usage : AVR handling AV streams, DRC (audissey), bitstream decoding, powering central channel and surround, feed external power amp for mains
- music usage : streamer feeding minidsp flex stereo (dirac) feeding power amps.

My AVR was merely used an HT processor and took lots of space.

My unique AV source (internet provider TV box) is used for TV, movies, video streaming and has the ability to do bitstream decoding and can output LPCM.

Thus, replacing my Flex stereo with a Flex HT, removing the AVR and just added an tiny invisible eARC switch (Earc not supported by my TV) gave me same capabilities and saved me lots of space and wattage consumption.
And was able to handle both AV and music use cases.

I've always used Logitech Harmony huhmb and remote. Thus it was very transparent at usage.
 
I don't plan on replacing my AVR but does an eARC splitter degrade either the audio or video to the downstream devices in any way?
 
I don't plan on replacing my AVR but does an eARC splitter degrade either the audio or video to the downstream devices in any way?
I believe it's digital and therefore unlikely? I would love someone to confirm. I wonder the same.
 
I believe it's digital and therefore unlikely? I would love someone to confirm. I wonder the same.
I'm thinking another external device becomes another possible entry point for noise/distortion unless everything in the loop has the best shielding possible (only asking for learning so hope someone knowledgeable chimes in)!
 
I replaced my HT Processor with a MiniDSP FlexHTx, and concur with these points...its perfect for my (niche) use case but for most cases I'd still recommend an AVR.

To enumerate the benefits for me over an AVR:
  • More "programable". I have a RPI connected to my MiniDSP and via https://github.com/mrene/minidsp-rs I'm able to control the MiniDSP remotely. I also made my own simple web app to control the MiniDSP. https://github.com/danielhstahl/minidsp-remote-control
  • Smaller/lighter/less heat. 1mu is awesome
  • The flexibility to handle any 8 channel output. I have 5.2 and one unused channel; if I ever get another sub I still won't need another device. I can integrate MSO/REW to my heart's content.
 
Does your TV not support eARC? My understanding is that you only need the HDFury or similar in the case of older TVs without eARC. Is there any other reason?

And I'm not able to find this anywhere else, can you have a separate config (stereo vs 5.1) based on input? I'm thinking 5.1 for eARC, stereo for SPDIF.
 
Does your TV not support eARC? My understanding is that you only need the HDFury or similar in the case of older TVs without eARC. Is there any other reason?

And I'm not able to find this anywhere else, can you have a separate config (stereo vs 5.1) based on input? I'm thinking 5.1 for eARC, stereo for SPDIF.
Most (all?) support 2 channel but not multi.

Yes to the second, 4 presets.
 
I would think that the Flex HT/HTx will never replace AVRs for the obvious reasons. It could, and might eventually, become a viable device that replace an AV preamp processor if either they got the licensing things sorted, and/or the user is willing to use it with a separate devices to handle the decoding of the lossless contents including Dolby, DTS etc.

I bought mine for my two channel use with DLBC PC version only, but am interested in a low cost solution for using it as a backup to my 7.1.4 AVP in case of something that I hope will not happen for many years. These devices are fun to play with, currently I am having fun using it with DLBC but play with the mini's PEQ/Biquad manually, very flexible, and I think more practical than customizing DL's target curve just to fine tune/smooth off a few dips/bumps post DLBC calibration.

They use non reference class DAC ICs that are similar to those used in AVRs such as the X6800H, C30, RZ70 and higher model AVRs, but they evidently implemented them better, using differential schemes and might have use better OPAs than those used in the AVRs mentioned. Still, measurements do show them in >110 dB SINAD rangge, that the likes of the much raved Anthem AVM90, Marantz AV10, Lyngdorf, Arcam etc. AVPs could not achieve on on the test bench so far, not even close in fact. So, there is still potential/possibility that in the future (might be distant futre), that minidsp might come up with something that could compete, but not replace, for various reasons with the high price AVPs for certain HT applications such as the low channel count applications.
 
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I'm thinking another external device becomes another possible entry point for noise/distortion unless everything in the loop has the best shielding possible (only asking for learning so hope someone knowledgeable chimes in)!
A properly implemented extractor will be completely transparent. Bits are bits. A defective design or example can harm your bits.
 
More "programable". I have a RPI connected to my MiniDSP and via https://github.com/mrene/minidsp-rs I'm able to control the MiniDSP remotely. I also made my own simple web app to control the MiniDSP. https://github.com/danielhstahl/minidsp-remote-control
Cool. Thanks for those links.

Smaller/lighter/less heat. 1mu is awesome
You need amplifiers somewhere.

I have a Flex (2in 4out) and it's case is surprisingly hot, a good deal hotter than the Buckeye NC252MP it feeds.
 
Thank you @Mort for writing about your experience. I was thinking about doing the same thing. I bought a Raspberry Pi with 8 channel dac and hdmi capture card to test whether it will sound better than an AVR before spending money on a Minidsp Flex HTx.

I am going to use a WiiM Ultra (USB out to Pi, Camilla DSP for EQ, out to a usb dac) for music and AVR for movies with a Bobwire RCA1 to automatically switch between them.

Then later in the year, play about with the 8 channel dac and hdmi capture card.
 
Why would you do that? The Denon x4800h is not so bad and can achieve great sound if calibrated correctly, such as using A1 Nexus or Neuron script. You could just use the X4800H in a 5.1 setup.

I've added an external 4-channel Buckeye Amp (Hypex) to my X4800H and took some time to calibrate it using A1 EVO Nexus, and now I'm more than happy with the results.

Betting on an HT solution from a company that is very new to HT is never a good choice.
 
Cool. Thanks for those links.


You need amplifiers somewhere.

I have a Flex (2in 4out) and it's case is surprisingly hot, a good deal hotter than the Buckeye NC252MP it feeds.
Interesting, I've had no such issues with the HTx. My Buckeye amp does get hot though; I've recently added another 4mu rack so my Buckeye amp can go on top and have more ventilation. The HTx is on 24/7 without any heat buildup despite being inside a closed rack.

 
Interesting, I've had no such issues with the HTx. My Buckeye amp does get hot though; I've recently added another 4mu rack so my Buckeye amp can go on top and have more ventilation. The HTx is on 24/7 without any heat buildup despite being inside a closed rack.


Same here, my 4XHD always ran hot, or let's just say very warm, but not the HT and HTx. My thought is, the 4XHD is probably "hot" because of the tiny enclosure, but the Flex enclosure are as big as the Flex HT so I really don't know why it would run "hot".
 
I found the DDRC-24s to run very hot.
Both my Flex and Flex HT just warm, about the same as my buckeye amp before my fans go on.


Thank you @Mort for writing about your experience. I was thinking about doing the same thing. I bought a Raspberry Pi with 8 channel dac and hdmi capture card to test whether it will sound better than an AVR before spending money on a Minidsp Flex HTx.

I am going to use a WiiM Ultra (USB out to Pi, Camilla DSP for EQ, out to a usb dac) for music and AVR for movies with a Bobwire RCA1 to automatically switch between them.

Then later in the year, play about with the 8 channel dac and hdmi capture card.


I was using a Bobwire RCA1 before I moved to the Flex HT. I love that device.
 
I recently swapped my old AVR for a Flex HTx.
I have it connected to the eARC of my LG 77C2 screen. An Apple4k TV is connected to a 'normal' HDMI input.
Setting it up so the A4TV is in PCM only with the LG passing it to the Flex HTx was simple.
Getting the CEC volume/mute commands from the A4TV was fiddly. I actually have no idea why it started working, it just did.

I am looking at getting a small USB streamer so I can listen to TIDAL or Airstream without needing the TV on.
 
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