DVR Security System – Pros & Cons

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Camera Type – Analog
The cameras used by a DVR system must be analog security cameras, better known as CCTV cameras. Most of the cost savings found by using a DVR system is due to the camera. While you can mix and match cameras in your home security system, there is less flexibility in the type of cameras you can use with DVR systems.

In a DVR system, the analog cameras stream an analog signal to the recorder, which then processes the images. The advantage of this system is the reduced complexity required of the camera when compared to an NVR system.

Cable – Coaxial BNC Cable
The camera connects to the DVR recorder via a coaxial BNC cable. Although the use of coaxial cable may not seem significant, it does have some limitations:

  • As the coaxial cable doesn’t provide power to the camera, there are actually two cables included within one covering – a power and video cable. The cables separate each end to provide the separate functions. As such, you’ll need to install your DVR recorder near a power outlet.
  • The size and rigidity of coaxial cables can make installation more challenging. The coaxial cable is wider in diameter than Ethernet cables used with NVR systems which can make it more difficult to run cables in tight spaces. Coaxial cables also tend to be more rigid, compounding this problem.
  • However, if your property has existing coaxial connections for a previous security system, you can use the same cable to connect your new system.
  • Standard coax cables do not support audio. A variant that with an added RCA connection is needed but even with these a DVR has a limited number of audio input ports so only a small number of cameras can record audio.
  • The image quality on coaxial cable will begin to degrade after about 300ft/90m, which can limit the ability to which you will extend your security presence outward. Lower quality cable will result in a signal loss at shorter distances.

DVR recorders rely on a hardware chipset known as an AD encoder, which is responsible for processing the raw data streaming from the camera into legible video recordings. DVR systems also have different requirements when it comes to the recorder. Specifically, in a DVR system, the user must connect every camera directly to the recorder. In comparison, an NVR system only requires that each camera connects to the same network. Also, in a DVR system, the recorder doesn’t provide power to the cameras. Each camera connection will need a splitter that supplies power to enable cameras to function.

System Flexibility
DVR security systems are less flexible than their NVR counterparts in terms of camera type and mounting options. Whereas NVR based systems can integrate both wired and wireless security cameras, DVR systems can only use wired security cameras. DVR systems also have less flexible mounting solutions, because routing coaxial cable can be more difficult in tight situations and a power outlet is required for each camera.

Image & Audio Quality
As we’ve discussed, in DVR systems the cameras transmit analog video via the coax cable directly to the recorder and images are processed at the recorder level. The analog signal results in a lower quality image compared to NVR systems. Coaxial cables also don’t natively transmit an audio signal, and DVR recorders usually have a limited number of audio input ports.