Shock v. Glass v. Radar. Best Sense?

Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=37664
Printed Date: May 14, 2025 at 10:57 AM

Topic: Shock v. Glass v. Radar. Best Sense?

Posted By: Chromic-Chris
Subject: Shock v. Glass v. Radar. Best Sense?
Date Posted: August 18, 2004 at 12:54 PM

The big three senses...Glass breakage sensors, Shock sensors, and Radar motion detectors.

What is the best? For me, I really HATE hearing the siren 99.999% from my own cause or the noisy flase alarms like the Harley that started a few feet away....even though sensitivity is adjustable, I see the shock sensor as mostly false alarms.

The glass sensor seems great, but that only gets the guy who broke your window. I figure most "bad guys" can slim jim past your door most of the time.

Then there's Radar. Someone needs to tell me exactly how this works. I figure it is mounted inside the car, under the dash to detect motion IN the car, but I understatnd these detect motion OUTSIDE (a near perimeter of) the car as well.

If this is true, how can you dial in an exact perimeter? (i.e. someone parking next to you not setting it off)

At this point I would probably use Radar only, and turn the siren off and just let my remote let me know when somethings wrong.

Can radar be adjusted to ONLY detect motion IN the car???

Thanks for your help!!!!

Replies:

Posted By: kgerry
Date Posted: August 18, 2004 at 3:58 PM

a good quality shock/impact sensor will be your best for reliability and lack of falsing

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Kevin Gerry
Certified Electronics Technician
MECP First Class Installer

Owner/Installer
Classic Car Audio
since 1979

Posted By: Chromic-Chris
Date Posted: August 18, 2004 at 10:14 PM

Please explain how a shock sensor is less falsing than a motion/radar?

Posted By: Teken
Date Posted: August 18, 2004 at 10:35 PM

Sensor(s) 101:

1. Buying a known quality sensor from a alarm maker.

2. Install it in the correct place which offer the most uniform and balanced sensing.

3. Affix the sensor with the correct hardware. Many people use zip ties, double sided tape, velcro etc. I prefer to use SS sheet metal screws.

4. Ground the sensor to actual chassis / frame using a star washer, and ensure the shortest cable length.

5. Adjust the sensor(s) semi-anually to ensure consistent protection and coverage. This will reduce the amount of false alarms.

A) A shock / motion sensor is intended to detect impact to the chassis. There are still many rubber band units around. The next level is the use of piezeo crystal. The next is micro processed time delay with piezeo detection.

B) A radar sensor is intended to provide the vehicle and the owner / theif notification that an alarm is present. Which can either alert you, or them to come or go. There are many forms of radar, doplar, infrasonic, ultra sonic sensors.

Again the brand, and the manufacture dictate as to how well they perform. But it is up to the user to apply them in such a manner so as they prove effective and do what they are intended for.

They all have a level of *attack / decay* which you must allow for and compensate for.

The so called glass sensor that is being sold by the many makers are no more than noise sensors. A true glass detector measures and is tuned to the frequency of breaking glass.

All of which are affected by tint, surface area, and the tools of the trade to circumvent them.

They are 1001 things I could tell you about any sensor(s). You as the user, must know, and fully understand what it is your trying to do.

1. Protect the vehicle?

2. Protect the contents of the vehicle?

3. Provide you, the owner or thief a measure of notification?

4. All of the above?

Regards

EVIL Teken

Posted By: sroth140
Date Posted: August 19, 2004 at 1:33 AM

glass is intended for people who actually know how to break a window with out shock. otherwise a shock sensor covers the window. thats why they tend to false from motorcycles and other heavy vibration sources. they dont know the differance, but its good to know theyd go off if a window was smashed. the glass sensor is designed to keep out a higher level of theif that uses pressure to pop a window with minimal impact.

if you are worried about someone just using a slim jim, dont you have the door triggers hooked up? besides if a window get smashed... the theif will usually unlock the door and open it, again thats what the door trigger is for.

on a final note, i hate my proxy sensor. its a perfect install but it will false out of no where. it could false 5 seconds after you arm it, or a day later just sitting in the same spot all alone in the garage. i unplugged the thing and im not even going to bother takeing it out. as far as im concerned im saving someone else the trouble of trying to make it work. DEI usually has a great product but i hate that thing.

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MECP certified installer