Monoprice HTP-1 Home Theater Processor Review

[Xulonn]

@Xulonn, was this the flaw are/were referring to? I don't consider it a flaw. It is an artifact of the analysis. The APx-585 analyzer does not exhibit the same behavior as it has preset settling times enabled by default.

Being a decades long audio enthusiast and not an industry professional or electronics engineer, I was not referring to a specific technical issue, but rather to the overall impression I got from the review that indicated that the unit had lots of minor issues, including idiosyncratic design elements and features that one does not expect from a $4k AV processor.

I'll leave it to you and the other pros to sort out the technical details. I am aware of your discussions of the technical details regarding operating ranges and testing parameters, but not qualified or experienced enough to comment on most of them.

BTW, I appreciate your participation here, and a little pushback on opinion-based criticism from other pros can often lead to productive discussions. There are lots of opinions expressed in science and science-based discussions - objectivity is not an absolute.

 

[MC_RME]

My example was to add 10 dB boost to a 0 dBFS input. That should be 14 dB below clipping if there's 24 dB of headroom. Or are we using different definitions of headroom?

No, it is indeed 14 dB below our digital processing headroom. But I have the impression that you didn't get the point. With such a setting and provided the input signal already reached 0 dBFS the user will have to reduce volume with the big front dial by these 14 dB to prevent the DAC chip from clipping. And the user knows that he has to do that because the level meter tells him (just in case he couldn't hear it).

I am fully aware that AVRs usually have a different gain structure inside and have to provide lots of headroom (is there one with a level meter overview screen of the relevant stages? Never saw one...). That partly (!) explains the miserable SNR values they have. But not the distortion. Quite the opposite: reducing levels to -10 dBFS makes all current DAC chips on the market distortion-free. Seeing results like here therefore makes me wonder what happens in all the other processing chips. There seems to exist no real bypass? They all add lots of distortion? Or is the DAC section incompetently designed? I can't answer that, with AVRs I am just a normal customer.

 

[bigguyca]

Yes! The target consumers for the HTP-1 are using amplifiers ranging from 1.2V - 2.5V rms sensitivity and that is the optimal range of the HTP-1. You are going to flip your lid when you see how the Trinnov of StormAudio units measure at these low levels. I haven't completed the measurements but the basic SINAD (I see that ASR prefers the SINAD presentation over THD + Noise, so I will provide SINAD). It is at 4V and greater where they hit their stride (which makes sense as the Trinnov Amplitude amplifiers have a +18dBu sensitivity).

@amirm how did you come up with the 2.7V level (rather than 2.0V) to determine how the HTP-1 measures at lower output? I've browsed several of your reviews where you do measure at 2.0V (not 2.7V AFAICT).

This is no doubt a recently developed target since unfortunately the design of the HTP-1 doesn't do well at higher voltage output levels. No one would expect a higher-end $4k product to have such unacceptably low outputs. Those levels are just to bottom levels of even Marantz AVP's. Based on looking at the physical hardware design IMO the components are there to provide higher outputs and overall better performance, but unfortunately simple design decisions appear to have limited output. Frankly it's sad. Based on looking at the hardware (can be an error prone process, but the measurements reinforce the observations), details of the design, from DAC IC to output buffers, have been posted on the AVSForum and links provided to those posts earlier in this tread.

It is certainly clear why Monoprice didn't publish specifications ahead of time. No one would have taken the product seriously. It would likely have been DOA. The succession of schedule fails should have been an ominous indicator, but there was a tendency to give Monoprice the benefit of the doubt based on previous new products in the Monolith line.

The HTP-1 is such a contrast to Monoprice Monolith multi-channel amplifiers. Those amplifiers have, and have had, detailed specifications and lab reports done with AP equipment. The same is true for the Monolith Subs. Clearly, IMO, this absence of transparency was due to the measured performance we are seeing.

 

[bigguyca]

One fascinating piece of all this the attitude of some individuals on the various HTP-1 threads on the AVSForum. Huge amount so of digital ink were spent bashing Emotiva's various AVP's products on the HTP-1 threads. One individual even indicated that a some combinations of evidently attitude and intelligence prevented people from the Southern United States from successfully producing advanced products such a AVP's. Clearly Emotiva has not done an acceptable job of delivering its AVP's, but the bashing was frankly excessive.

Now that the HTP-1 has arrived late, with no hard spec's, no Monoprice provide measurements, and now some questionable performance measurements, many of these same people have developed very thin skins when issues concerning the HTP-1 are raised. Shoot the messenger(s) seems to be the order of the day. Lower the bar for measurements also seems to be in vogue, perhaps some sort of handicap as in golf or bowling will be suggested.

Soon the HTP-1 thread will likely have statements such as, "Well it's better than Emotiva!" Or "It's this much better than Emotiva," as if that was a high hurtle.

 

[bigguyca]

4 Volts is also a consumer target for balanced outputs.
If there is a sweet spot, then it should be published with the specifications. Better yet, show the THD+N for all power outputs. Some of us have amps with adjustable gain and this data is useful for gain matching.

- Rich

Agreed.

 

[bigguyca]

No, it is indeed 14 dB below our digital processing headroom. But I have the impression that you didn't get the point. With such a setting and provided the input signal already reached 0 dBFS the user will have to reduce volume with the big front dial by these 14 dB to prevent the DAC chip from clipping. And the user knows that he has to do that because the level meter tells him (just in case he couldn't hear it).

I am fully aware that AVRs usually have a different gain structure inside and have to provide lots of headroom (is there one with a level meter overview screen of the relevant stages? Never saw one...). That partly (!) explains the miserable SNR values they have. But not the distortion. Quite the opposite: reducing levels to -10 dBFS makes all current DAC chips on the market distortion-free. Seeing results like here therefore makes me wonder what happens in all the other processing chips. There seems to exist no real bypass? They all add lots of distortion? Or is the DAC section incompetently designed? I can't answer that, with AVRs I am just a normal customer.

As long as you are here, hope you don't mind: A couple months back I purchased your latest RME ADI-2 FS with the AK4493 DAC IC. A great product, worked out of the box, nice manual with extensive explanations, love the display, I could go on... Thanks for a wonderful product.

 

[GD Fan]

One fascinating piece of all this the attitude of some individuals on the various HTP-1 threads on the AVSForum. Huge amount so of digital ink were spent bashing Emotiva's various AVP's products on the HTP-1 threads. One individual even indicated that a some combinations of evidently attitude and intelligence prevented people from the Southern United States from successfully producing advanced products such a AVP's. Clearly Emotiva has not done an acceptable job of delivering its AVP's, but the bashing was frankly excessive.

Now that the HTP-1 has arrived late, with no hard spec's, no Monoprice provide measurements, and now some questionable performance measurements, many of these same people have developed very thin skins when issues concerning the HTP-1 are raised. Shoot the messenger(s) seems to be the order of the day. Lower the bar for measurements also seems to be in vogue, perhaps some sort of handicap as in golf or bowling will be suggested.

Soon the HTP-1 thread will likely have statements such as, "Well it's better than Emotiva!" Or "It's this much better than Emotiva," as if that was a high hurtle.

So, paranoid reactionaries from the deep south who ignore evidence and demonstrate cultish blind faith beliefs despite being led astray?

 

[santodx5]

Halo Guys,

I come to this forum because someone mention Trinnov. Can you measure it and let us know?

Thank you!

 

[amirm]

Drop them a note and say you want it measured here before you consider purchasing it.

 

[A/V Analysis]

Halo Guys,

I come to this forum because someone mention Trinnov. Can you measure it and let us know?

Thank you!

I have measured the Altitude 16 but the performance was less than stellar. I'd like to review the results with Trinnov to make sure there is not a problem with my individual unit, firmware, etc.

Observations/anomolies:
The A16 output maxes out at 6V (+18dBu) before clipping.
The noise floor is on par with other units, but the noise floor rises with 1kHz tone.
The A16 will not output anything when receiving the multitone. It simply mutes.

 

[A/V Analysis]

4 Volts is also a consumer target for balanced outputs.
If there is a sweet spot, then it should be published with the specifications. Better yet, show the THD+N for all power outputs. Some of us have amps with adjustable gain and this data is useful for gain matching.

- Rich

Do you know what your Emotiva is outputting? It uses a version of the AK4490 and the same CS3318 as the HTP-1.

 

[A/V Analysis]

@amirm, does it ever make sense to test AVRs and processors also with DSP engaged since that is how the unit will most likely be used? Or would the results be the same?

They likely perform resampling and attenuation (for headroom purposes), so it is worth testing. Only if I had more time to devote to them....

This is another project I have in the works (it is time consuming).

With Trinnov audio altitude 16, i've meusered reference level at -23 dB's on the volume control..

This level, in some recordings is much higher than most os us can tolerate..

In other recordings, it is tolerable up to -5dB's, almost 20dB's above reference level.

Go figure...

What amplifiers & speakers are you utilizing?

 

[Francis Vaughan]

I have a Lexicon 12B that I can measure if there is interest.

I would love to see some tests on this one. A while ago I spent some time going over the schematics, and there is a lot of care and effort apparent in the design (and a few perhaps questionable corners cut). However it is a pretty old device, and technology has moved on a lot. Seeing how well they actually did would be really interesting.

 

[Costas EAR]

amplifiers & speakers are you utilizing?

Atmos setup (7.4.4) with 11 pcs of Neumann 310 and 4 subs, 2 pcs Neumann 870 and 2 pcs Genelec 7071a, with Trinnov altitude 16.
Neumann 310's at low input sensitivity (adjustable).
Fully treated room, RT60 at 0.26 sec (trinnov measurements). 32-33m|2..
Roon, oppo 203 and Nvidia shield.
4k (native) sony projector by the way, on Stewart screen.

I can use the volume control up to +5 dB on Trinnov, at enormous spl levels (very short periods).

Typical reference level measured at -23 dB's.

Almost all movies at reference level, except a few of them which are mastered really very loud, but they are the exception.

I prefer listening music at -18 or -15. It feels like it is playing much lower than measured. No ear fatigue, smooth sound, very enjoyable.

PS. Listening distance for all speakers, exactly 2,3m. Exactly. Hemisphere of speakers. All speakers at exactly the right angle for atmos setup, as suggested by Trinnov.

 

[A/V Analysis]

Spoiler

My desire? The whole world of consumer hifi has standardized on 4 volt output. Pro gear goes way above that. It seems like the AV manufacturers got together in a back alley and decided to shrink the output as much as they pleased.

I have $150 DACs that output 4 volt output designed by a single individual. When did this get "hard" as to want to relax the standard set in music world?

To get state of the art performance where you have true reference levels and dead quiet noise floor you need to go higher in voltage. Here is the Purifi Amplifier: https://www.audiosciencereview.com/...easurements-of-purifi-1et400a-amplifier.7984/

Here it is with 4 volt input:

This is what happens when you disable the input buffer and gain drops to 12 dB:

You get 4 dB in noise performance.

Same is true of Benchmark AHB2 amplifier:

View attachment 49987

Best performance is reached in Low Gain that requires nearly 10 volts and you are advocating for even less output than 4?

Here are the specs for RME ADI-2 DAC:
View attachment 49988

That's 6.9, 3.46, 1.7 and 0.9 volts.

Why would the AV industry want to not only miss the Pro standard, but also dip way below consumer music standard?

You are new here but this is an old topic here. My stance is firm. If dirt cheap music DACs can produce 4 volts, the AV world better wake up to that as well. HTP-1 seems to be there by letting me input 7 volt sensitivity in the menu but clips way before that?

Now, if you could show me how I have saved $2000 by accepting lower output levels that would be one thing. But there is no evidence here. It is just a crappy design standard set among manufacturers. As reviewers, last thing I want to do is help them in that regard.

@amirm it appears that there is a processor that meets/exceeds much of what you detailed. The Lyngdorf MP-50 outputs 16 Vrms at 0dB volume and 0dBFS. There are four processors which share this design: Lyngdorf MP-50 & MP-60 and McIntosh MX-160 & MX-170.

I noticed that Nord's purify based amplifier has a lowish sensitivity: Input Sensitivity 8ohm 2.52Vrms 10.24dBu https://www.nordacoustics.co.uk/purifi1et400aamplifiers
I wonder what we will see from Lyngdorf's MX8400?

My active speakers (Funk Audio) can accept up to +23dBu (due to the AllDSP front-end). I suspect many active speakers have adjustable gains. I think gain is something many consumers don't understand to even think about when purchasing components, let alone optimizing gain throughout the signal path.

 

[LTig]

Atmos setup (7.4.4) with 11 pcs of Neumann 310 and 4 subs, 2 pcs Neumann 870 and 2 pcs Genelec 7071a, with Trinnov altitude 16.
Neumann 310's at low input sensitivity (adjustable).
Fully treated room, RT60 at 0.26 sec (trinnov measurements). 32-33m|2..
Roon, oppo 203 and Nvidia shield.
4k (native) sony projector by the way, on Stewart screen.

Wow!

 

[santodx5]

I have measured the Altitude 16 but the performance was less than stellar. I'd like to review the results with Trinnov to make sure there is not a problem with my individual unit, firmware, etc.

Observations/anomolies:
The A16 output maxes out at 6V (+18dBu) before clipping.
The noise floor is on par with other units, but the noise floor rises with 1kHz tone.
The A16 will not output anything when receiving the multitone. It simply mutes.

Can you email Trinnov and ask them? I have listened to Trinnov A32 and compare to Marantz 8802A I had, there is no comparison!!

It is the best processor I have heard to far! but i never test other high end one such as storm audio.

What is multitone?

Thanks

 

[SimpleTheater]

Monoprice answered my question about 24 bit data being truncated, saying “The ASR measurement was incorrect. There is no truncation of 24 bits. There can be a short delay as the decoder detects a stream as PCM. The PCM input sensitivity control is designed to eliminate this delay. The delayed startup due to the PCM detection setting caused the test to falsely report bit truncation."

Then deleted my question and the answer.

 

[A/V Analysis]

Can you email Trinnov and ask them? I have listened to Trinnov A32 and compare to Marantz 8802A I had, there is no comparison!!

It is the best processor I have heard to far! but i never test other high end one such as storm audio.

What is multitone?

Thanks

I agree, it is the best processor on the market. But perhaps just not by the [unweighted] metrics of this thread (which don't directly translate to aural performance).

Sorry that I wasn't specific enough. I have reached out to my U.S. contacts at Trinnov. I know my local guy is in Europe for ISE. I'm not sure about the other. Although I reached out on Friday, it was already after 5 in the East (3 hour time-zone difference). As it is a weekend, don't expect a response until Monday.

 

[A/V Analysis]

Monoprice answered my question about 24 bit data being truncated, saying “The ASR measurement was incorrect. There is no truncation of 24 bits. There can be a short delay as the decoder detects a stream as PCM. The PCM input sensitivity control is designed to eliminate this delay. The delayed startup due to the PCM detection setting caused the test to falsely report bit truncation."

Then deleted my question and the answer.

I suspect manufacturers don't want any links to publicizing/pointing customers to ASR on their site. In this case the incorrect measurement and analysis still remain in the review. The information is inflammatory and misleading to consumers. While I don't agree with @amirm leaving the review as is, I must respect it (it is his forum).

If my testing is accurate (and I suspect it is), the results are going to be quite a bit disruptive to the high-end market. Often, disruption is the only way to affect change. I just prefer to confirm accuracy before putting everything out for the world to see.