Remote Edit

With small studios, tracking happens close to the DAW and, in this Very Small Studio, the DAW display is mounted with the piano keyboard. While this is convenient for tracking and keyboard work, a piano bench is not the best position for editing, mixing and mastering. Larger recording studios have the luxury of separate and isolated control/mix positions with an engineer. For the Very Small Studio; a Remote Edit position is a partial solution.

Concept
The Studio is a system designed to solve all those nasty issues like hum, noise and acoustics. However, once tracks are recorded, a significant amount of basic editing and preliminary mixing could be done remotely.

A downstairs Office computer can provide a limited Remote Editing space for the upstairs Studio. While the office is not the best acoustic environment, a lot of preliminary editing work is still possible in that space thus potentially leaving only the final cleanup and mix in the Studio -- which is where the good monitors, mix-cubes are located within the better acoustic space.

Duplicating the Studio hardware in the office would be difficult and expensive. The better option is to construct just a "remote control" of the DAW by extending a "copy" of the DAW's screen, keyboard and mouse plus DAW output audio. The Remote Editing position can have "acceptable" monitors, great headphones, CD-quality Studio audio and an exact duplicate of the DAW screen.

Note, the Remote Edit studio is not saving a "remote copy" of the audio. The full resolution 96kHz/24-bit track data always resides in the Studio; while you listen to a 44.1kHz/16bit copy. In theory, one could just route a good quality stereo cable but there are other more complex signals to handle such as the DVI DAW video image. Remember, 15-feet is generally the max distance for a DVI extender cable so a different approach is required.

Signals
The Remote studio signals include:
  • Copy of the DAW screen DVI video (at full DAW resolution)
  • Stereo CD-quality audio from the DAW's A/D box (FireStudio Project in this case)
  • Control of the DAW keyboard and mouse USB input
Keyboard, Video, Mouse and Audio (KVMA)
First, the Studio computer's keyboard and mouse are USB so they require minimal bandwidth.

Next, a 2-headed video card in the DAW computer can drive both the local Studio display and a remote display by setting the Win-7 display mode to 'duplicate'.

Finally, high-quality Audio is readily available from one stereo output pair from the PreSonus Fire Studio Project box. For remote editing, it should be enough to just send the Studio's A/D hardware's stereo output (the same source as you'd send to the Studio Monitors) to the Remote as long as it retains sufficient quality.

Note: As long as the Studio system is up and running, the Remote Editing console will have 'parallel control'. It also means that it would be easy to drive the Studio monitors without being there to hear what is happening -- so obviously some care is required. One easy solution is to temporarily power-down the power amplifiers for the Studio monitors.

Connections
The most difficult signal to send is the high-resolution DAW computer screen as expecting a PC graphics card to drive a cable longer than about 15 feet can degrade the video signal.

Data Path
A quick check on the WEB located a "bitrate calculator" (http://web.forret.com/tools/video_fps.asp?) which shows that full 24 frames/sec video at 1680x1050 resolution would require a data transmission rate of 380 Mbps. While wired LAN can provide this bandwidth, the typical 54 Mbps WiFi simply won't work. So, because of the difficulties (for home esthetics in this instance) a series of experiments were performed in search of alternatives to CAT-5 wiring.
  • The Remote video monitor must handle the same exact resolution as the Studio DAW monitor.
  • The addition of CD-quality audio to the data stream, 100-300 Mbps network bandwidth should be expected.
So, what are the options for constructing a 300 Mbps network?

The Solution ...

Wired
THIS IS THE ONLY PRACTICAL SOLUTION: The simplest configuration is just run a CAT-5e cable from transmitter to receiver. This has the widest bandwidth and the greatest noise immunity. However, it can also be difficult under some circumstances to run and/or hide a cable.
    • Cat-5 cable is good for up to 100 meters(328 feet) at 100 Mbps data rates
    • Cat-5e cable is good for up to 100 meters(328 feet) at 1 Gbps data rates

IP-LAN KVMA
There is an amazing box from Avocent: The LVIP-HR 'LongView' remote KVM which consists of a 'transmitter' at the Studio computer and a 'receiver' at the Remote Editing position.
    • The two units connect to each other via their own, separate LAN network. While the LVIP-HR pair can directly connect to an existing Wireless or Wired network via standard WLAN J45 ethernet cables, wireless badnwidth is too narrow so a separate WIRED LAN is the only real solution. However, that only requires a CAT-5e LAN cable directly connecting the two boxes; no other hardware.
    • CD-quality audio is encoded a 44.1 kHz @ 16 bits in stereo which should be sufficient for editing.
    • This Studio requires ~120 feet of Cat-5e, following a circuitous path, but the connection is "near-transparent". Given that reasonably-priced wireless methods cannot provide the bandwidth, this is clearly the best (and probably only) solution -- despite the headaches related to routing and hiding the cable.
        Conclusions
                The transmitter/receiver pair is sepacialized, but the CAT-5 connect is flexible and easy.

FiberOptics
While not purchased, the options are easy to understand. FiberOptic networks have much wider bandwidth and the fiber cables are small and not horribly expensive. Fiber-to-WLAN converters can be obtained for <$100 and pre-made fiber-optic cables come in many lengths.

Conclusions
While fiber-optic networks are very fast, they are no different than having to run 100+ feet of CAT-5 cable as a 'line' still has to be routed; except that fiber is more expensive.

Other Experiments ... which all failed:

Wireless Bridge
Two Wireless Access Points (WAPs) (with directional antennas) were configured as Bridges. Each end included a broadband LAN Switch to allow the Bridges to talk to the transmitter and receiver. The Switch arbitrates the LAN traffic based only on the MAC addresses of the transmitter, receiver and Bridge so no local router is required. In fact, a router would only slow the traffic so is not a good choice. Here's the equipment selected for the experiments:
    • TP-Link TP-WA801ND Wireless AP/Bridge (2 each)
    • TP-Link TL-ANT2409A Flat-Panel directional antenna (2 each)
    • TP-Link TL-SG1005D Gigabit Switch (2 each)
    • This network is totally separate from any other local WiFi network and the wireless Bridges should be configured to use an RF channel that has less traffic to avoid bandwidth-limiting WiFi signals. The Bridge configuration uses WPA encryption and the Bridges are set to only recognize each other's MAC address to avoid any intrusion. This wireless network is exclusively a 2-way radio data link, to replace a CAT-5 cable, and nothing else.
    • The wireless Bridge has 2 "rubber-duck" antennas wired for "diversity reception". The antennas are actually "dipole" configurations with only about 3 dBi (just 3dB over a "point source" idealized antenna). The small "flat panel" directional antennas are still only about 5dBi. So, it is necessary to improve the gain so as to provide the best signal strength possible -- so as to get the most bandwidth. One method is to add a "corner reflector" to the antenna pair to form a direction beam with up to over 10dBi of gain.
Conclusions
After many experiments, including the construction of a corner-reflector to re-shape the dual antenna pattern and add about 10dB of forward gain, the data rate remained so low as to only achieve just the bare minimum threshold for acquiring a video image. However, the image remained unstable. In fact, 811g with only 20 MHz max bandwidth was slightly more stable than 811n and 40 MHz fixed bandwidth. This was despite only a distance of about 20 feet -- though admittedly it was angled through several walls and a floor. 300 Mbps broadband wireless truly requires obstruction-free "line of sight" with large antennas.

AC PowerLine LAN
Some experimentation was performed with the latest ZyXEL AV2 PowerLineAdaptors but with poor results. PLAs are modules which plug directly into the AC power line, providing a 'wired' LAN connect via an 30-80 MHz wide-spectrum, multi-modulation carrier. While the LAN end of the device performs a function similar to Wireless Access Points, the PLAs send their signals over the AC wiring. The do work; but over a very short distance and are dependent on the exact standards to which the AC wiring was installed. Outlets on different AC line phases will not communicated well; or even at all. Not having a 3-wire grounded system also limits the bandwidth.
    • Note: While the devices claim 600 Mbps (at the MAC layer level), in reality (with the devices literally plugged into the same AC line connect, they max out at 100 Mbps when you include the necessary router or switch. Even just "2-rooms" away, the data throughput can vary from about 30 Mbps down to just 3 Mbps.
Conclusions
While these sounded like a great solution, they cannot provide anywhere near the 380 Mbps bandwidth for the best remote screen resolution.

Equipment List
  • Avocent 'LongView' LPIP-HR KVMA IP-LAN Extender (transmitter-receiver pair)
  • VisionTek 2-headed PCIe graphics card (DAW computer)
  • 150 ft of CAT-5e cable
  • VisionTek 1-head graphics card
  • StarTech SV231DVIUAHR 2-Port High-Rez DVI VKMA Switch
  • M-Audio AV-40 Monitors
  • Shure SRH-840 Stereo Headphones
Near-Field, Remote Edit Monitors
For Remote Editing, good near-field monitors are just as desirable as Studio near-field monitors. However, since the Remote Edit space acoustics are definitely poor by comparison, the cost/quality tradeoff heavily factored the cost. Below is a simple comparison of specs and street cost of a few monitors just to give a "feel" for what is presently available.

Conclusions
In my opinion, as of 2014, M-Audio AV-40s are the best option when wanting to keep the cost down for an "office/edit" space. The best eventual "moderate-priced" upgrade would be to the Yamaha HS-5s.

 Mfg  M-Audio
 Behringer
 Yamaha
 Genelec
 Focal
 Model  AV-40
 MS-16
 HS-5
 8020C
 CMS40
 Price  $150
 $80
 $400  $1,070
 $850
 Woofer(in)  4
 4
 5
 4
 4
 Freq-Response(+-3dB)  85Hz-20kHz
 80Hz-20kHz  54Hz-30kHz
 65Hz-21kHz
 50Hz-28kHz
 Cross-Over  2.7 kHz
 N/S 2.0kHz
 2.0kHz  N/S
 Power-Out  20 W
 8 W
 70W
 40W
 50W
 Headphones  Yes  Yes  No
 No
 No
 Input(connect)  RCA  RCA,3.5mm
 XLR,TRS
 XLR
 RCA,XLR
 Height(in)  8.75  9.5  11.2  9.5  9.4
 Width(in)  6.0  5.5  6.7  5.9  6.1
 Depth(in)  7.25  5.5  8.7  5.6  6.1
 Weight(lbs)  14  4.6  11.7  8.1  11.0