Well, a bit of background to kick things off. I upgraded my speakers to Kef Rs about 2 years ago, and had intended to buy a new AVR once Atmos came out. Between that, my wife and I had our first child, so it was a bit pointless upgrading for the sake of it!
We now find we are able to sneak in the odd movie and I thought we may as well upgrade to Atmos too!
The shortlist was always the Anthem 1120, then came along Arcam with the 550 and Dirac, so it got added to the shortlist too.
After demoing both, they were both very similar in sound quality with the Arcam having a slight edge. Considering it had Dirac, that ended up being my choice (despite effectively being $2k more once you get extra amps for Atmos).
At home with the Arcam......
Once I got it home, that is where all the problems started. The idiots at Arcam put out a dodgy version of the Dirac software on the website, which failed to work with my calibrated Umik-1. Additionally, the rubbish microphone Arcam provide failed to work too. I wasn't too happy.
After some sleep, I was kindly sent the previous version of the Dirac software. This at least worked with my Umik-1, although it isn't the easiest software to get running. Basic TV viewing was sounding great, so it was time to get onto some demo material.
I immediately got out the Dolby Atmos demo disc and played a few clips which went well, until I got to the Horizon Demo. This is where the next round of trouble started. The Arcam kept shutting down at the same point in the demo clip at reference volume. I was a bit puzzled, surely the Arcam would have enough grunt for this? Well, the answer is a bit more complicated. Checking the Dirac filter, it applies a 10db boost around 150hz, about the same spot my 8ohm rated speakers drop to around 3.2ohm on their impedance curve. Basically, the Arcam (550 at least) cannot handle difficult loads very well, which is why it was shutting down. Testing with Dirac off it passed this same test, and it also passed with Dirac on at 10db less volume.
Ok, well I figured that would be solved by a power amp, so I could live with it for the time being. Some more viewing (via Plex on XboxOne), saw the Arcam flick between a 5.1PCM and 7.1PCM source, despite the XboxOne being set on 5.1PCM. This was something minor that I could live with, but Arcam just dismissed this blaming the source.
I also had been reading all the issues with Dirac on AVS, which seemed to blow up during my period of ownership. Testing on my end using REW, easily replicated the same issue. Basically, the correction filter for one speaker (i.e. Left Front), was still being applied on content sent to the sub. Playing a few more familiar clips, the bass disappeared from my room (7db reduction between 35hz to 65hz), so much so even my wife noticed. Arcam technically firstly dismissed this complaint, then commented that the filter at a certain frequency is correcting the room, so it shouldn't matter what speaker it was sent to. Obviously this is total BS! I said to Arcam technical, that if they were intending to solve the issues I would be happy to keep the product, otherwise I would seek a full refund. Anyway, they maintained there was no problem so I got a refund.
+ Great sound quality (just ahead on Anthem)
+ Great build quality
+ Dirac very effective above the crossover, especially at low listening levels
- Dirac implementation is (currently) incorrect (unless you have genuine full range speakers)
- AMP cannot handle difficult loads
- Some HDMI issues
- Rubbish included microphone
- Very expensive in Australia, even more expensive once you had amps for Atmos
- Likely needs power amps with difficult speakers
At home with the Anthem......
Well, with the Arcam gone I could immediately notice the difference going back to the Denon, but thankfully it was only for a few days. Setting the Anthem up was extremely easy, it was all just very logical. First impressions are good. I quickly had everything plugged in, all the inputs renamed and was ready to run ARC (although not at midnight). Waiting until the next morning, I was very impressed with ARC. The microphone is very impressive, and the software is also very impressive. This is a very polished product! A minor issue with running ARC, it was misinterpreting the 150hz null in my room as the speaker roll-off, so I just manually adjusted that, which was again very simple!
Ok, straight into it. Can it handle the Dolby Horizon demo clip? Yes, it certainly could, and it was even louder than when the Arcam shut down! I was impressed, but how did it handle bass? Straight onto a few demo clips and the room came alive. I was a very happy camper!
Just to double check, I measured with REW and the hole the incorrect Dirac implementation created was virtually gone. A few tweaks with ARC quick measure improved things even further, so I did another calibration which improved things a little further.
+ Great sound quality (just behind Arcam)
+ Good build quality
+ Excellent amplification, it seems effortless and no need for power amps
+ Quality included microphone
+ ARC is a very polished product and very simple to use
+ 11amp channels on board
+ Great pricing in Australia
- Looks a bit cheap
- Display not the easiest to read (I'm nitpicking)
Well, to be honest they are both outstanding products, but the Arcam is particularly let down by their incorrect implementation of Dirac (which they are only now starting to investigate). I would give Anthem the win, but (ignoring cost) if Arcam do fix Dirac, I would give it the edge overall.