AVP-A1HDCI Video Tests & Audyssey Analysis

Denon has really reached the pinnacle of performance with the video processing capabilities of this processor. I loved the transparent OSD that overlays on the picture via HDMI. I’ve been waiting for this type of feature to come to market on pre/pro’s and best of all without compromise in picture quality. I ran a 480i signal out of my DVD-5910CI to the AVP-A1HDCI via HDMI and had the processor do the scaling and upconverting. I was pleased to note a perfect score (130) for HQV testing and full resolution via Avia test patterns. The AVP-A1HDCI was basically giving me indistinguishable results whether it or my DVD player did the processing and scaling. This isn’t too surprising considering both units have virtually identical video processing capabilities. Give the AVP-A1HDCI a quality interlaced signal and it will reward you with the very best picture quality the format is capable of delivering.

Audioholics/HQV Bench Testing Summary

Denon AVP-A1HDCI Benchmark Score: 130/130 (perfect score – it doesn’t get any better than this!)

*Source component was the Denon DVD-5910 set to 480i via HDMI output upscaled by the AVP-A1HDCI to 1080p and fed to the Epson Pro Cinema 1080UB Projector.

A real bonus to me was applying Realta processing to my Verizon FIOS service. I helped smooth out motion artifacts and extract the very best picture quality possible. Even some of the non high def channels looked deceivingly good. I was really digging Star Trek Enterprise, and the HD music channel in 1080p. Best of all I didn’t need to switch calibration settings on my projector since I dialed everything in on the AVP-A1HDCI via the input I was using for my FIOS service.

Audyssey Room Correction Analysis

I’ve reported Audyssey test results in countless reviews of A/V receivers that featured it in the past but I thought it would be prudent once again to illustrate how well it does on a flagship product while also covering Dynamic EQ.

Calibration Results (1/12^th octave) of Denon AVP-A1HDCI (left) vs Audyssey MultEQ Pro (Right)

Although I measured all seated positions in my theater room, I thought it would be best to focus on the money seat to compare how well Audyssey built into the AVP-A1HDCI faired against my stand alone Audyssey MultEQ Pro processor which sells for $2500. The calibration results are a combination of my two main channeIs playing simultaneously with all four of my subwoofers. I was able to achieve good post calibration results via the AVP-A1HDCI (+-6dB from 12Hz to 200Hz) but they weren’t quite as good as what I achieved with my Audyssey standalone box (nearly ruler flat sans the room suckout around 85Hz) running a special editor software Audyssey provided me so I could go in an customize the results. This isn’t surprising since the Audyssey standalone processor has double the resolution compared to its implementation in any A/V receiver or processor. I am hopeful once Denon releases the Audyssey Pro with receiver editor software for this processor, I can better dial in my calibration to nearly duplicate my original results without having to install another box between my pre/pro and amplifier. I will report back on this once the software becomes available.

Dynamic EQ Frequency Response Comparison @ Various Listening Levels

With Dynamic EQ (DEQ) engaged, you can see the bass boost below 70Hz of up to +10dB when listening at a 70dB average SPL. Once you start cranking the volume up, DEQ proportionally lowers the boost as you can see at the listening level of 80dB where the bass boost was a mere +3dB or so below 35Hz. If you look at the full range measurement I took of my front speakers, you will notice a modest boost of the high frequencies above10kHz with a slight recession in the 4-6kHz region. Perhaps the slight recession I measured in the midrange region partly explains why the vocals seemed get pushed back a bit in my Diana Krall listening tests I discuss later in the review.

Overall Averaged Response Across Six listening Positions

I applied an averaging algorithm to my LMS measurement system to chart out 6 listening positions with and without Audyssey calibration. With Audyssey engaged, it did smooth out the system bass response and I am certain once I have the curve editor feature, I can tune it in even better.

Audyssey Equalization Results: Denon report (left pic); Actual measurement (right pic)

One thing I am not thrilled with is the fact that Audyssey does up to +9dB boosting. It’s usually NOT a good idea to boost levels since they are likely caused by room nulls and the end result is wasting power with little to no benefit for flattening frequency response. The Audyssey results show nearly +10dB boosts on my dipole/bipole surround channels and up to +5dB boosting on my mains. I also measured the preamp outputs of the main channels (above right pic) to quantify the results. The red trace represents no Audyssey while the yellow trace is “Audyssey” and the blue trace is “Flat”. It’s interesting to note an overall drop in signal level when either Audyssey calibration is engaged with a rather dramatic boost in the high frequencies in “Flat” mode. I am very eager to do some curve editing to minimize the boosting while tweaking other areas in the bass response.

Volume Scaling Issue

Upon getting my AVP-A1HDCI fully calibrated, I was prepared to start doing some listening tests. I started out with a few CD’s engaged in PLIIx Music Mode. The system sounded great as I kept pumping up the volume and was a bit perplexed that I quickly hit max volume and it wasn’t all that loud. There I was with a $14k separates rig from Denon which was barely sustaining 85dB SPL levels in my theater room. What gives, I asked myself? I soon realized that once I engaged Audyssey, it severely limited the max volume level in the AVP-A1HDCI. Upon further investigation, I discovered it was a combination of Audyssey + 7.1 post processing surround Mode (ie. PLIIx Music Mode, DTS, Neo, etc) that was leading to this problem. Combine this deficiency when listening to a low compression source with an inherently low signal level, and you’ve got a receipt for severe volume limiting. I ran into this scenario quite often when using my Toshiba HD-A2 HD DVD player to playback discs recorded in Dolby TrueHD and even after I boosted the input level by +10dB and turned Audyssey off, I still found myself wanting to turn the volume higher than it would let me.

What appeared to be happening is an issue with the overall gain structure and the demands from multiple processes placed on the volume IC’s utilized in this product. The list of processes that require headroom is quite long which include THX, Subwoofer gain compensation (up to +8 dB), channel trims (up to +12 dB), downmixing (up to +11 dB of headroom in the worst case), Tone control, MultEQ (up to 9 dB), and others. So, in a worst case scenario (e.g. if you are in downmixing mode and the trim on your sub is near the max, or perhaps tone control is on) you will not be able to reach master volume indication above 0 dB. Denon is NOT alone here. Other manufacturers are facing this issue but they are a bit more clever hiding it. For example, I’ve come to find out that the latest generation of Onkyo receivers have a similar issue, but the volume indicator will always allow the user to reach max volume despite it won’t continue to get any louder beyond a certain point.

An industry insider has indicated to me that a new technology is enabling Volume IC chips with higher headroom and they will start to become available next year. Unfortunately this does no good for consumers facing this problem now with the current generation of products, but I do have some suggestions to help minimize the impact.

• Scale down your channel trims – if you have your sub boosted to +3dB, scale it back to 0dB while also scaling back all other channels by 3dB
• If the sub levels were boosted in the processor during setup, adjust them down to 0dB or lower and proportionally increase their respective levels via your subwoofer(s) master volume control
• Increase source level per input as needed
• If using the POA-A1HDCI, bridge the front channels if you’re got two channels to spare. This will increase your output level by +6dB
• Don’t use tone controls or downmix options
  

By trimming down two of my subwoofers from +2.5dB and +1.5dB respectively, I got back 2.5db of gain on my master volume but I also had to turn down the channel trims on all other channels the same so it was essentially a net wash. However, I did play with input source level adjustments and was able to set the source to +7dB without causing the max master volume limit to decrease. Thus I got back a some of the headroom with this trick and I suggest you experiment with it should you run into a similar issue when engaging Audyssey room correction in a post processing mode such as PLIIx Music/Cinema.

Hopefully the forthcoming EQ editing feature for Audyssey will allow the user to limit the boost (especially on the surround channels) to minimize headroom loss and ensure you can never reach the limit of the volume control in any listening situation.

Until this issue can be resolved, I have no choice but to lower the performance rating of this processor to a 4.5 / 5 though this product revealed benchmark performance in every test I threw at it in the lab.  I also feel it important to note that according to my contacts at Denon, I am the only user currently reporting this as an issue despite the hundreds of consumers currently enjoying this product.