Monoprice Monolith HTP-1 Surround Sound Processor Review

PRICE $3,999

16-channel processing and output
Extensive customization options
Dolby Atmos, DTS:X, Auro-3D support
Dirac Live with Bass Control sub integration
Setup may intimidate casual users
No onscreen display

With support for all key immersive audio formats, 16-channel output, and Dirac Live room correction, the Monolith HTP-1 surround sound processor punches well above its price class.

It's been interesting to watch the evolution of Monoprice in the home theater market following the introduction of its Monolith product line. Monolith encompasses a broad range of components, including speakers, subwoofers, and amplifiers, all produced in partnership with big names in A/V product design and development, and all offering impressive performance at a strikingly low cost. The company's latest market disruptor is the Monolith HTP-1 surround sound processor, a stunning freshman effort that includes features typically seen only on components that cost significantly more than the $3,999 HTP-1.

The HTP-1 is one of the most feature-laden processors I've encountered to date. This 16-channel design supports the latest surround formats including Dolby Atmos, DTS:X, and Auro-3D, and features Dirac Live room correction along with the new Dirac Live Bass Control subwoofer integration and equalization. Monolith's processor is also Roon Tested and fully software- and hardware-upgradeable.

The HTP-1's nice, textured aluminum front plate features a touch-controlled display that can be set to always-on, dimmed to different levels, or switched off entirely. All front-panel operation and setup features can also be accessed from a web browser on a laptop or tablet by navigating to the HTP-1's IP address. This is the first processor I've used that allowed this, and I was really impressed with the capability. Most models instead use an onscreen display, but I found I preferred IP control as it let me make changes on the fly without interrupting what was happening onscreen.


The HTP-1's remote control is fairly basic, and its keypad can be hard to navigate in the dark. There's no backlighting and most keys don't provide much in the way of tactile differences. I did appreciate its selection buttons for surround modes and presets, however, along with numerous other features you would normally want to control directly instead of navigating through a setup menu.


Back-panel connections include eight HDMI 2.0b inputs and two full-bandwidth HDMI outputs, including one with eARC. Switching is fast and the HTP-1 doesn't tamper with the video signal, instead simply providing pass-through for up to 4K/60Hz signals with Dolby Vision and Hybrid Log Gamma HDR. There's no multichannel analog input, but a pair of stereo analog RCA inputs are provided along with AES/EBU and three each coaxial and optical digital inputs. There's also a USB type-B audio input, though it was not activated on my review unit. (Monoprice says that USB audio input support will be part of a software update that should be available by the time you're reading this.) The HTP-1's back panel additionally features an Ethernet port, Wi-Fi antenna, and a trigger input and outputs. For audio outputs, the HTP-1 uses balanced XLR connections for all 16 channels plus a single set of stereo RCA jacks.


To say the HTP-1 is customizable would be a dramatic understatement. Here, the Monolith punches way above its price point, offering a level of setup flexibility I've previously seen only on cost-no-object processors from high-end brands like Trinnov and Datasat. Consequently, those expecting the cut- and-dried setup options found on most processors in the under-$4,000 range are likely to be overwhelmed by the options presented in the HTP-1's setup menus. (I almost feel that its menus may be too dense.) Setup is broken down into different subsections, including speaker, calibration, input options, sound enhancement, connectivity, and more. For the daring, there's also a signal generator that can be used to fine-tune your speakers along with full parametric equalization options for all channels.

The HTP-1's flexible speaker setup options allow for up to six overhead channels, wide channels, and up to five independently adjustable subwoofers. The traditional 7.1-channel surround setup is hard-coded, but the other eight channels can be configured to support different speaker and subwoofer combinations.

Along with manual parametric equalization for all channels, the HTP-1 offers Dirac Live room correction and takes full advantage of the latest iteration of Dirac Live (version 3) with optional Dirac Live Bass Control functionality offered as a paid upgrade ($349 for a single sub, $499 for multiple subs). To run Dirac Live, you'll need to download the Windows/Mac application from the Dirac website to a laptop or desktop computer (Dirac's smartphone app is not supported by the HTP-1). While Monoprice doesn't include a calibrated USB microphone with its processor, Dirac recommends using the MiniDSP UMIK-1 ($75, available at, which is what I used for my review.

This was my first experience using Dirac Live in my own theater, and I was impressed not only with the results, but the high level of customization it offered. Dirac Live is similar to solutions such as Audyssey and ARC, but it offers correction of both frequency response and impulse response in the time domain, and also provides adjustable target curves. It's also the only solution I know of that can correct more than two subwoofers automatically with full time-alignment support. Audyssey can do this with dual subs (if the specific Audyssey version supports SubEQ), but Dirac takes things further by offering correction and time-alignment for up to four independent subwoofers. I used the Dirac Live Bass Control with two independent subwoofer pairs for this review and found the software yielded highly accurate crossover filtering from the main channels, along with better time-alignment of subwoofers than I've been able to achieve in the past with Audyssey—something that had a huge impact on sound quality with both music and movies.

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drny's picture

Thank you Kris. I fully trust your evaluation process and review conclusions.
I'm sure the HTP-1 is a very good processor, however, I suspect that your enjoyment had much to do with magnificent Revel Ultima Salon 2 for your three front stage channels. You sir have a fantastic Home Theater setup, anchored by the JVC RS3000 reference level projector.

mars2k's picture

Finally!..this proc has been like a mirage for what seems like an eternity. So glad to see a reliable review. Thank you...
now for the "this free beer is getting kinda warm bit"
Would like to have seen a little more elaboration around the DAC section. Ok Roon ready but are the DACs good enough for me to give up my Lumin D2?
For those of us not familiar with your system....what power section were you using? Or for that matter were there any other analog or digital sources beyond your disc player...while we're on the subject ... what was that? An Oppo 205 perhaps...hard to tell.
Like I said...I like my free beer cold but thanks again. Finally someone has actually played with this unicorn
BTW...the fine people at DataSat actually developed this piece for Monoprice just like ATI sources most of the Monolith amps. Take it with a grain of salt but I heard some gossip around DataSat producing a sister model to this as an entry level product but decided not to for some marketing or brand reason..
At any rate this unit did not spring fully formed, as in Botticelli's Venus on the HalfShell, fully formed into the universe but rather leverages some of the best development skill, tech and history in the market.

ptruce1's picture

Hi Kris, I bought an HTP-1 in Oct and returned it a week later after spending an inordinate amount of time trying to get it stable enough to work. But I found it was a GREAT idea for a processor and hope to purchase it later when some of the problems have been solved.

My questions:

1. What firmware version did you use?

2. Did you have on site assistance from Monoprice ins setting up the device? I do not mean to question your expertise, but some in the LA area have had a visit from the Monoprice team especially early on to solve some tech problems.

3. I use Auro3D and was under the impression it was not possible to setup a system for both
Auro3D and Atmos. If I read the article correctly you were able to test both decoders. How was this accomplished? Do you have two speaker setups: heights for Auro3D and Tops for Atmos?

4. When calibrating with Dirac, were you able to use the Bass Control module with multiple subs?

5. The final straw for me was if I "shutdown" the system, it would not boot up again without disconnecting the ethernet cable first. Did you just leave the unit on all the time?

As mentioned above, I find the HTP-1 an exciting product and one that could lead the way forward to more immersive systems that can automatically correct the room for 4 subs. Just didn't work for me this time.


Hubbman's picture

Would love some additional details here. Everything I’ve read about this processor has been very positive.

I would like to know what Monoprice had to say in response to your return and dissatisfaction. Was there a reply and attempt to resolve? Might this be an issue with your experience level and perhaps taking on a more complex piece of technology (not a knock, just wondering, as this system does appear to require some expertise and patience to navigate)?
I’m personally concerned due to the fact that I’ve just placed my order, and again this is the very first negative I’ve come across.


ptruce1's picture

No, I am not alone with the problems with the HTP-1. Check out the AVSFORUMS for the 6,000+ posts on this unit. Some people have had great luck with the unit, while others like myself have had to return them due to unacceptable flaws. Recently, the level of support has dropped off, but I think you will get great support on the forum. When the unit just wouldn't boot up, that was the reason for me returning it. I fully expect to buy it again after the issues have been nailed down. I would guess that you have an 80% chance of having a positive experience. Peter

Musicjohn-NL's picture

Will this device allow me to play multi-channel SACD's from my SACD player via HDMI to the unit? The DAC used in the Monolith is very capable of SACD decoding. Just can't find any information about whether it actually does (or not). If not, I'd render this unit useless for my purposes, as I also like listening to my collection of SACD's.

katherinerose6's picture

It was my first time utilizing Dirac Live in my own theater in gutter screen installation St Paul, and I was really pleased with the outcomes as well as the extensive flexibility it allowed.

katherinerose6's picture

Dirac Live was something I had never used in my own theater before, and I was impressed not just with the outcome. See:

joedavidson's picture

For those not familiar with your system like, what power section were you using?

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joedavidson's picture

Finally, someone has actually played with this unicorn while searching how much to build a retaining wall.

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