Monoprice HTP-1 Home Theater Processor Review

[Xulonn]

Christine Balfa. 45 minutes of pure triangle bliss.

Surely you can appreciate her triangle plus vocals, which have a certain feline quality, and take the required frequency range of your audio system down a few hundred Hz...

 

[JEntwistle]

And as mentioned by an avsforum member:
“Sorry for being novice, but comparing a $9 DAC to HTP-1 is kind of comparing a $9 steering wheel to the entire car, is it not?”

No, I would respectfully disagree. Just because the HTP-1 has other functions in addition to a DAC does not explain why its DAC has to be subpar. That is my question - why is that necessarily so? What is the technical reason for AVRs to underperform given functions?

I am not saying there are no good reasons; just that no one has given them yet, if they exist.

 

[Sancus]

Personally, I'd have preferred a 4000$ processor with 8 AES/EBU outputs, so I can use whatever DAC I fancy. DANTE or RAVENNA would be a great alternative...

This is one of the compelling things about the JBL SDP-55, I think, even at its higher $6K price point. The Dante functionality would allow digital outputs with the right adapters.

I've been considering one of these high-end processors for a while now, and I'm starting to struggle to see the value of the Monoprice one, to be honest. The Denon AVRs have acceptable performance as long as you don't exceed certain voltages. So, the same issue as the Monoprice HTP-1. Low voltage outputs seems to be a trend among AVRs for whatever reason.

In terms of features, an AVR-6500H will get you:

• 13 channels instead of 16.
• RCA outputs instead of XLR.
• Audyssey XT32 instead of Dirac.
• HDMI 2.0 with no upgrade, but HTP-1 HDMI 2.1 upgrade requires a great deal of trust in Monoprice to actually do it for a reasonable price.
• No fancy OLED screen
• Does have some playback features the HTP-1 does not have, like Airplay 2.

Both have:

• Auro3D + Auromatic
• All decoding capabilities, Atmos etc, are the same(I think?).
• eARC confirmed to be functional with LG OLED TVs.

The JBL SDP-55 adds:

• Airplay 2, built-in Chromecast, etc.
• Dante for true digital outputs and very powerful network audio routing capability.
• Logic16, which only has value if it's better than Auro3D/Auromatic, but we don't know yet.
• Claims of a high-end DAC implementation(ESS Sabre 9028 Pro).

The AVR-6500H is a 2-year-old product, so while its MSRP is $2200 you can probably find it around $1500 or less now if you look. For +$2500 the HTP-1 adds Dirac, XLR out, and 3 more channels. The value of 3 channels in home theatre is sketchy, in my opinion, because of the huge number of Atmos releases that are pinned 7.1.4 audio. In general, there is little Atmos content that will properly use more than those 12 channels, without upmixing. XLR outs and fancy screens are nice to have, but hard to put value on. And Dirac... is commonly believed to be better than Audyssey XT32, but Audyssey XT32 with configurable target curve via the app is quite good, so this is challenging to put a high value on.

For an additional +$2000, the JBL adds Dante, which is a genuinely compelling feature for those trying to do high-end setups. This leaves the HTP-1 in a weird middle place, where it's not really high-end, but doesn't seem to offer that much value unless you believe Dirac and 3 channels are worth >$2000.

This definitely assumes the JBL SDP-55 is well engineered and not broken in some way, which will require testing. And maybe I'm missing something in my analysis.

 

[Xulonn]

And as mentioned by an avsforum member:
“Sorry for being novice, but comparing a $9 DAC to HTP-1 is kind of comparing a $9 steering wheel to the entire car, is it not?”

Unfortunately, the HTP-1 has the equivalent of a sticky old 1959 Nash Metropolitan steering wheel, not one from a new Honda.

 

[Xulonn]

This is one of the compelling things about the JBL SDP-55, I think, even at its higher $6K price point.

Specs look interesting for that unit - I hope Amir can test it.

 

[amirm]

A Proposed Reason for the Excess Distortion in the HTP-1

It seems unproductive to make the same posts on a separate website so here is a link to a post on the AVSForum as to why the HTP-1 may have excess distortion . The link is based on looking at the hardware so there are of course uncertainties as to if the observations match the actual design. There are previous posts a few posts back on the same AVSForum site that provide more details of the design of the HTP-1 from the DAC IC to the output.

Input on all this would be great.

https://www.avsforum.com/forum/90-r...lith-htp-1-owners-thread-40.html#post59240064

Post with an overview of the design:

https://www.avsforum.com/forum/90-r...lith-htp-1-owners-thread-39.html#post59238228

https://www.avsforum.com/forum/90-r...lith-htp-1-owners-thread-39.html#post59238376

I was going to suggest to go and give him a like on AVS just to realize it is you here as well. Very good detective work. I don't have the patience to do the detective work you have done there. I think the only response would have to come from Monoprice on whether your analysis is correct.

For now, I am impressed by the performance of Cirrus Logic volume control.

 

[jhaider]

First, even after paying $4,000, you don't get a measurement microphone with this processor! I don't know what they were thinking. So out of box, I can't perform any automatic EQ testing. Second, I have tested the EQ systems on a number of products in the past like Lyngdorf, Paradigm (with Anthem ARC). For the most part the better designed ones work well. However, keep in mind that almost all of them lie about the corrections they perform.

That's needlessly harsh. In my reviews of SSPs and AVRs with Audyssey (Marantz, Denon) and Dirac 1 (Bryston) I took confirmatory measurements. I intentionally paid no attention to the original proscribed measurement positions. The results lead me to believe the provided graphs are reasonable.

Caveat is what they don't measure or show you, notably mains-sub integration, may be terrible and require substantial manual remediation.

(But no included microphone? That is surprising.)

The graphs they show are simulated correct curves, not remeasured. Indeed remeasuring is almost impossible if you move the microphone during measurements as is required. You would have to accurately remember 3-D positions of each position to repeat it which is not very practical.

I've written it before and I'll write it again: any system whose performance is not substantially confirmed when using a spatial average from a different random microphone spatial average over the same listening area is inherently pointless.

 

[laurelkurt]

How much does this thing weigh? I looked at the specs and see only dimensions. 5 year replacement warranty seems great. I wish they'd do a scaled down 7.2 or even 2.2 with Dirac/bass management. I'm actually hoping to see NAD C-658 streamer/DAC/preamp tested.

 

[Noah Katz]

Third, the real test of an EQ system is to listen. Yes, "trust your ears." A single microphone and certainly electronic instrumentation cannot convey what two ears hear in an acoustic environment.

Totally agree.

Did you listen to the HTP-1, and if so what were your impressions?

 

[Srrndhound]

With volume set to 0 dB (red), there is no compression visible. Max output is now limited to 2.9 volts. Why that would be good for an amp that has 7 volts sensitivity, I don't know.

Max output is not really limited to 2.9 V. Without post processing adding several dB of possible gain, the amp will not be reaching its max output. In contrast to DACs, which require no headroom for additional processes, that's a big part of what happens in AVPs. That also helps explain why we will not see AVPs with the same noise floor as DACs. In a DAC, 0 dBFS runs the Dac chip to its full output. In an AVR, it may be several dB lower (design dependent).

 

[amirm]

Max output is not really limited to 2.9 V. Without post processing adding several dB of possible gain, the amp will not be reaching its max output. In contrast to DACs, which require no headroom for additional processes, that's a big part of what happens in AVPs. That also helps explain why we will not see AVPs with the same noise floor as DACs. In a DAC, 0 dBFS runs the Dac chip to its full output. In an AVR, it may be several dB lower (design dependent).

So? Benchmark, RME and other DACs like them have headroom to deal with inter-sample overs. And in the case of RME, has internal DSP to boot. Indeed the need for headroom instructs one to build robust output buffer with far higher capability for output than what we see here.

 

[amirm]

Did you listen to the HTP-1, and if so what were your impressions?

Hi Noah. Good to see another familiar face from AVS days.

I have not listened to it. If it had come with a mic, I would have tested its EQ and listened that way.

 

[Srrndhound]

So? Benchmark, RME and other DACs like them have headroom to deal with inter-sample overs. And in the case of RME, has internal DSP to boot. Indeed the need for headroom instructs one to build robust output buffer with far higher capability for output than what we see here.

Inter-sample overs add what, 3 dB?

RME has an internal DSP? Feed in 0 dBFS. Measure S/N. Now add 10 dB boost. What happens to the output? The S and the N.

 

[amirm]

RME has an internal DSP?

Of course it does. What kind of question is that?

 

[Srrndhound]

Of course it does. What kind of question is that?

View attachment 50130

Rhetorical.

 

[amirm]

Feed in 0 dBFS. Measure S/N. Now add 10 dB boost. What happens to the output? The S and the N.

You are making a statement or asking something? If the latter, you need to explain better. I am not a mind reader. And tell me how much you understand about electronics and DSP so I know at what level to answer you. Until then, here is the RME measurements:

 

[Srrndhound]

You are making a statement or asking something? If the latter, you need to explain better. I am not a mind reader. And tell me how much you understand about electronics and DSP so I know at what level to answer you. Until then, here is the RME measurements:

View attachment 50131

We were talking about the addition of post-processing's impact on system S/N. The RME is a DAC with post processing, so I am wondering how that impacts the S/N. The simple test would be to first establish the THD+N ratio same as you did for the HTP-1, with a 0 dBFS input. Then use the RME's DSP (can be EQ, tone, or gain) to add 10 dB to the input signal. Then look at THD+N again. I'm not exactly sure what to expect because I do not know what their " adapted analog output stage" does. But I'd be interested to see these results if you have time to do them. Thanks!

I worked at Dolby for 25 years, so while I'm no DSP engineer, I've picked up a few things along the way. Talk technical if you like.

 

[amirm]

Is that you Roger?

 

[Srrndhound]

Why, yes. How nice you remembered.

 

[MC_RME]

To shorten the back and forth: we have 24 dB digital headroom. In your example the output would run higher than 0 dBFS. This is clearly shown on the level meters as overload, so the user will turn the volume back to reduce output level and get an undistorted output signal. Apart from that most users operate at -20 dB and lower for volume , so never experience this kind of limit.

I am with Amir on this: I would expect the HTP-1 to be able to output full level when fed 0 dBFS input at a volume setting of '0 dB', undistorted. Analog headroom behind the digital volume control for digital processing sounds strange to me.

Edit: just read that the unit uses an 'analog' but digitally controlled volume control.