Monoprice HTP-1 Home Theater Processor Review

[markus]

Why don’t you summarize them here also?

Too much work I'm still in talks with them so haven't posted my final verdict yet.

 

[krizvi786]

Yes wiuld be appreciated

 

[yourmando]

That would make sense. I would think Dirac designers thought of this and is one reason for their mixed filter approach. Also, they need lower latency to work well with video and even games.

Maybe @mitchco’s charts show more of a Trinnov limitation because it is clearly worse than the PC version w/ plenty of taps. As the DSP guy, I’d love to see him do a head to head of the main DSPs on hardware vs PC. He has seen state of the art results already from Dirac on PC.

@HighImpactAV made an excellent comment re Dirac and the use of IIR filters for the bass.

It would indeed be interesting to see a multi-channel head to head comparison of Audiolense vs Dirac.

If one really wanted to tweak and customize, I guess one could also use moderately priced Denon with pre outs or the HTP-1 to just to handle the HDMI switching and decoding.

Then use an AD/DA device such as the Motu 16a w/ 16 analog in & outs, and do DSP in the PC using Audiolense or Accurate or Dirac to compare, or to solve specific problems.

As along time Audiolense user I agree with what you are saying. However, both Trinnov and Dirac use IIR filters for the bass. Trinnov lets you set the transition frequency. The default is 150 Hz. Various Dirac processors have a different number of taps to use. The maximum is 3048 taps per channel for 32 channels and is used by StormAudio. The cheaper processors using Dirac have less taps. I think Trinnov uses 4800 taps has a maximum based on the maximum filter length of 100 ms.

One thing rarely shown or discussed is that the phase is not corrected correctly in the bass by any system including Audiolense. The impulse measurement is measuring the energy of the highest frequency of the subwoofer and not the energy at the crossover. Using a dual channel measurement system like SMAART reveals this issue. REW can't show it. The Dirac Live Bass Control does a much better job and implements all-pass filters to address this issue. I've suggested a manual intervention for advanced calibrations when using Dirac Live Bass Control.


It is also important to realize that the higher the sample rate, the less accuracy in low frequency correction with FIR filters if the number of taps stays the same. For 1024 taps, 192 kHz has a frequency resolution of 187.5 Hz. This is one reason why I prefer to use 48 kHz for all content. The article FIR Filter for Audio Practitioners states that frequency resolution of the filter is worse than you say: For a quick and rough estimation, we can multiply the frequency resolution by 3 (three) to predict the effective low frequency limit of the filter. 46.875Hz x 3 = 141Hz. This means an FIR filter with fs = 48kHz and N =1024 will be effective at 141Hz and above.

The largest Audiolense calibration I've done so far is 15 channels. I'm building my own new theater and hope to compare 24 channels of Audiolense vs 24 channel of Dirac correction, but might not get around to it for another year or so.

 

[lashto]

Too much work I'm still in talks with them so haven't posted my final verdict yet.

hopefully you can post a link to your "final verdict" when ready.
That avs thread is running so fast and going so many directions, it's almost impossible to follow anything

 

[krizvi786]

hopefully you can post a link to your "final verdict" when ready.
That avs thread is running so fast and going so many directions, it's almost impossible to follow anything

Too much work I'm still in talks with them so haven't posted my final verdict yet.

are your "talks" with them influencing your final verdict?

 

[krizvi786]

are your "talks" with them influencing your final verdict?

i went ahead an ordered one myself to try it out, tired of waiting for everyone else's "unbiased" 2 cents

 

[markus]

are your "talks" with them influencing your final verdict?

Yes of course. You feel it shouldn't?

 

[stunta]

EDIT: an obscure setting fixes the linearity/muting issue. This setting should be the default, not the other way around

Anyone know if this is fixed by a newer firmware?

 

[markus]

Anyone know if this is fixed by a newer firmware?

There's nothing to be fixed. Any AVR/P has to reliably detect the format of an incoming audio stream. This takes time and results in sound missing at the beginning. If you allow for a less reliable detection method or rely on good faith (input was PCM last time so assume it's still PCM) loud noises might grill your speakers.

Having said that the option for setting detection behavior should be enabled by default though.

 

[Krobar]

There's nothing to be fixed. Any AVR/P has to reliably detect the format of an incoming audio stream. This takes time and results in sound missing at the beginning. If you allow for a less reliable detection method or rely on good faith (input was PCM last time so assume it's still PCM) loud noises might grill your speakers.

Having said that the option for setting detection behavior should be enabled by default though.

Yes, in particular there is a need to detect DTS CD. Amir is consistent in criticising this behaviour but I don't understand why; his testing could easily include a preamble to resolve this non-issue.

 

[stunta]

I am confused. if this is just an issue with default setting, why the beheaded panther? Is there something else I am missing? Are there other red flags?

 

[Krobar]

I am confused. if this is just an issue with default setting, why the beheaded panther? Is there something else I am missing? Are there other red flags?

Earlier AVRs/prepros were expected to perform the same as stereo equipment, this was an unrealistic expectation and ratings became softer on them over time; the HTP-1 was reviewed relatively early. There are no red flags however it was not tested using HDMI.

As long as HDMI input perform as well it is a much better choice then the Denon 8500 as a prepro IMHO. It has XLR outputs which are of big benefit if you use active speakers or active subwoofers with XLR inputs and Dirac. On top of that the HTP-1 offers full parametric EQ and 16 channel processing. If you are a gamer who intends to purchase a next gen console then Denon will likely pull ahead due to HDMI 2.1.

 

[stunta]

Here is something interesting I found on Page 62 (!) of the user manual:

So Dirac limits sample rates! This could explain why the miniDsp DDRC-88A also has this limit. Doesn't matter to me much personally - I dont think my ears can tell the difference between 16/48 and 24/96 anyway.

 

[TimoJ]

So Dirac limits sample rates! This could explain why the miniDsp DDRC-88A also has this limit. Doesn't matter to me much personally - I dont think my ears can tell the difference between 16/48 and 24/96 anyway.

No it doesn't. Some processors just don't have enought DSP power for higher sample rates.

 

[Krobar]

Here is something interesting I found on Page 62 (!) of the user manual:

View attachment 82650

So Dirac limits sample rates! This could explain why the miniDsp DDRC-88A also has this limit. Doesn't matter to me much personally - I dont think my ears can tell the difference between 16/48 and 24/96 anyway.

Thats normal, Dirac processes at 24/48 in most cases. A few very expensive prepros process at 24/96 but it is of questionable value:
Theta - 24/96 Dirac with Stereo only
Datasat RS20I - 24/96 always

The Monoprice has Dirac Bass Control offered which the prepros above do not.

 

[stunta]

I wish it allowed more control over subwoofer crossovers as an advanced option (automatic can be the default). In my specific case, I have 3 of them that I have configured to my liking using the DDRC-88A.

 

[Krobar]

Do you mean control of the LFE low pass filter? I think the Paramteric EQ and to a lesser extent Dirac bass control allow some control over the individual subwoofers.

 

[stunta]

Do you mean control of the LFE low pass filter? I think the Paramteric EQ and to a lesser extent Dirac bass control allow some control over the individual subwoofers.

Not the LFE. My current setup is Subwoofer 1: 80Hz, Subwoofer 2 & 3: 80 - 200 Hz. 2 & 3 are Rythmik FM8. I wonder if I set the crossovers on the physical units, will it auto-calibrate but the Dirac calibration screenshots on the manual don't show subwoofer FR as a selectable option on the right at all to confirm.

 

[Krobar]

Not the LFE. My current setup is Subwoofer 1: 80Hz, Subwoofer 2 & 3: 80 - 200 Hz. 2 & 3 are Rythmik FM8. I wonder if I set the crossovers on the physical units, will it auto-calibrate but the Dirac calibration screenshots on the manual don't show subwoofer FR as a selectable option on the right at all to confirm.

So Subwoofer 1 does 0-80hz and the others do 80-200hz?

I suspect you can achieve this with Parametric EQ which runs ahead of Dirac in the DSP chain but I dont own an HTP-1 and hopefully an owner can confirm (Or deny).

 

[stunta]

So Subwoofer 1 does 0-80hz and the others do 80-200hz?

Yes.

I suspect you can achieve this with Parametric EQ

Not sure how. I understand with the correct Q value and slope this might be achievable, but its a bit beyond my current level of expertise (or lackthereof)