One thing that has certainly made small conference rooms easier to integrate in recent years has been the introduction of “all-in-one” presentation systems. These units typically offer an integrated video switcher, scaler, audio switcher, amplifier and, more recently, integrated control system. Crestron and AMX have had their respective MPS and DVX systems for years. However, they both have recently introduced their HD-Base-T versions with the DMPS and DVX-xx5x Series. While, I had previously used the DMPS-300, I had not tried the AMX version because, quite frankly, it had just been introduced and the receiver boxes and wallplates were not yet released.
After taking a minor gamble and siding to trust AMX’s scheduled release dates for wallplates and receivers, I used the DVX-2155 for a project. We let our AMX account representative know of the short timeframe required for this integration and were pleasantly surprised when everything was received ahead of schedule. As with most jobs, that gave us time to fully assemble the rack, pre-program and test the system before final on-site commissioning.
Out Of The Box Issues
Excited to test out our new DVX, I plugged the unit in and disappointingly found that while the LEDs lit up, the front panel LCD display was dead. After opening the unit up, I found the front panel ribbon cable disconnected. Easy fix…or so I thought. Now that the front panel was fixed, I plugged in my wallplates and receiver box expecting them to light up from the built-in POE on the DXLink inputs and outputs. All devices were dark. I wasn’t entirely sure if maybe there was something that needed to be enabled in the unit, so at this point I called AMX. Tech support was very surprised that the ribbon cable was disconnected and explained that they had taken extra care to make sure that all of the new DVX products were QC’d twice. He also let me know that, judging from the serial number, I had the sixth unit produced off of the assembly line.
I was curious what could have happened, so I again removed the cover and re-examined the cables. This time I discovered that the DXLink power supply header (the DVX appears to use a dedicaed secondary power supply) was atached but off by one pin on one of the daughter boards. OK… Plug the unit in again and… The DXLink receiver box lit up! Unfortunately, the wallplates did not. At this point AMX said, “enough is enough”, apologized and overnighted a new unit. The new unit worked just fine. Someday I’d like it find out how in the world the headers were so messed up.
Aside from newer firmware that needed loaded and some online events that needed to be incorporated to make the DXLink work properly with the wallplates and receiver, installation and programming was rather easy. Once you get the device numbers and port numbers sorted out, switching and control are flat out simple. If you are using a DHCP server, endpoints (transmitters and receivers) will show up within Netlinx studio and can be assigned to a master via NDP. Instead though, I chose to use good old fashioned TCP/URL with static addresses. Something in me just doesn’t trust anything dynamic.
Switching performance on the DVX was mixed. On the built-in HDMI output, switching speed was unbelievable and in the range of analog switching times. However when used with a DXLink receiver, switching times were noticeably slower, sometimes taking up to 5 or 6 seconds to complete. Scaling quality was decent but not outstanding in my opinion. AMX still has some resolution and aspect ratios to tweak. I also had intermittent problems with the receiver getting “wacked out”. Occasionally, the display would have a pink hue, an ultra low-res scale, or appear to have been rendered using Nintendo 8-bit graphics. This would normally happen upon a system reboot. It appeared the receiver was initializing before DVX, so I resolved the issue by forcing a reboot of the DXLink receiver after the system was first booted. I reported the issue to AMX and it has since been resolved in later firmware revisions. Switching times have also been improved by around 3 seconds on the DXLink receiver.
Aside from my initial problems, I would have to say that I was generally pleased with the DVX. It provides a simple all-in-one solution and an easy method for control. My only complaint would be that the switch times could be further improved along with the scaling quality.
Stock photos by AMX
Jack is a certified AMX and Crestron control systems programmer and systems engineer. He holds InfoComm CTS, CTS-I and CTS-D certifications and has had a career in the A/V industry for over 15 years. He lives in Columbus, Ohio with his family where he works for a systems integrator serving various commercial markets.