How to Test and Compare Mount Vibration

This guide walks you through testing whether a mount or hardware change actually reduced vibration, then comparing the scans in a report you can share. In Speedometer 55, this workflow uses Resonance Scan.

What this tutorial is for

Use this tutorial when you want to answer a practical question such as:

• Which mounting point has the stronger resonance?
• Did tightening or damping the mount reduce the dominant vibration?
• Which setup excites the structure at a lower or higher frequency?
• Did a hardware change improve the vibration behavior enough to keep it?

This tutorial follows one rule: keep the test setup stable and change one thing at a time.

Before you start

Set up the scan so the comparison will mean something.

• mount the phone firmly
• keep the phone in the same position and orientation for all compared scans unless the mounting position itself is the thing you are testing
• use the same engine state, surface, or excitation source when practical
• change only one variable between scans

Good single-variable examples:

• before tightening vs after tightening the mount
• with damping pad vs without damping pad
• one mounting point vs another mounting point
• idle vs higher steady engine speed with the same mount

Bad comparison examples:

• changing mount, vehicle state, and phone position at the same time
• comparing one short idle scan with one scan taken under completely different load
• re-running the test after moving the phone without recording that change

Step 1: Prepare the settings

Open MENU > Modes > Engineering > Resonance Scan.

For the first useful comparison, only check these settings:

• Max session duration
• Show saved scan details prompt

Use a duration long enough to capture a stable vibration pattern. A very short scan can miss the dominant behavior. A very long scan is harder to repeat under the same conditions.

Keep the saved-scan details prompt on. It makes later comparison and reporting much easier because you can label the scan while the setup is still fresh.

Do not start by trying to test many operating conditions at once. First capture one clean reference scan.

Step 2: Run the baseline scan

The baseline is your reference scan before you change anything.

Suggested flow:

• open Resonance Scan
• confirm the duration is appropriate for the test
• if useful, add setup photos
• tap START
• hold or drive the system in the test condition you want to measure
• let the scan run long enough to stabilize
• tap STOP
• save the scan

When the saved-scan details prompt appears, label the scan clearly.

Recommended fields to fill:

• Test label
• Mounting location
• Operating condition
• Note

Good baseline labels:

• Windshield mount baseline idle
• Dash bracket baseline 2000 rpm
• Seat rail baseline rough asphalt
• Engine bay baseline fan on

Good notes:

• Phone in case, same clamp pressure
• Same operating state as comparison run
• Rigid mount, no damping pad
• Baseline for before and after test

Step 3: Change one thing and run the comparison scan

Now change one variable only.

Examples:

• tighten the bracket
• add damping material
• move to another mounting point
• repeat the same setup at a different steady engine speed
• compare the same mount before and after a hardware change

Then repeat the same run pattern:

• start a new scan
• keep the phone position and test conditions as similar as practical
• stop and save
• label the scan clearly

Good comparison labels:

• Windshield mount tightened idle
• Dash bracket with damping 2000 rpm
• Seat rail comparison rough asphalt
• Engine bay comparison fan on

If multiple things changed and you did not record them, the comparison becomes much weaker. The report may still be readable, but it will not answer a clean question.

Step 4: Read the results in a useful order

Do not start with every number at once. Read the scans in this order:

1. Dominant frequency
2. Resonance strength
3. Dominant axis

A practical reading model:

• the Dominant frequency tells you where the strongest repeating vibration sits
• Resonance strength tells you how strong that repeating response is
• the Dominant axis tells you which direction is carrying the strongest vibration

Then look deeper only if needed:

• compare whether the dominant frequency moved after the change
• compare whether the resonance strength dropped or increased
• check whether the dominant axis changed, which can reveal a shift in how the mount is flexing

Examples:

• if the dominant frequency stays similar but resonance strength drops, the change likely reduced vibration without moving the source frequency
• if the dominant axis changes, the modification may have changed how the structure is coupling vibration into the mount
• if both frequency and strength change, the hardware change may have altered the whole vibration behavior rather than just damping it

Step 5: Compare the scans

Use the saved scans as a comparison set, not as isolated measurements.

A good comparison answers:

• which setup produced the lower resonance strength?
• did the dominant frequency move in a useful way?
• did the dominant axis stay the same or shift?
• is the difference large enough to matter in practice?

Examples:

• if one mounting point gives much lower resonance strength, it is likely the better location
• if a damping pad lowers resonance strength without creating a worse new dominant frequency, it is likely helping
• if a hardware change shifts the dominant frequency out of the usual operating band, that can be an improvement even if some vibration remains

This is why clear labels matter. Without them, you may remember that one scan looked better, but not what was actually changed.

Step 6: Generate a report

Generate a report only after the scans are labeled properly.

A useful report should make these points obvious:

• what was tested
• what changed between scans
• which scan is the baseline
• which scan performed better

The report becomes much more useful if:

• both scans use clear test labels
• the setup photos or notes show the mounting difference
• the operating condition is recorded clearly
• only one comparison variable changed

Use reports when you want to:

• document a mount or hardware comparison
• justify a damping or mounting change
• share before-and-after vibration evidence with a teammate
• keep a record of which setup actually behaved better

Step 7: Share the result

Share after the scans and report are understandable on their own.

Before sharing, check:

• the scan names are clear
• the notes explain the setup briefly
• the report reflects the comparison you actually intended

A shared report is most useful when the receiver can understand the test without needing your memory of the setup day.

Common mistakes

• changing mount position and operating condition at the same time
• scanning too briefly to get a stable dominant response
• forgetting to label the baseline clearly
• comparing scans taken under clearly different load without noting it
• trying to compare setups when the phone position changed unintentionally between runs

Good first experiment

If you want one reliable first Resonance Scan test, do this:

• Scan 1: current mount, stable idle or steady condition
• Scan 2: same condition, mount tightened or damping added
• Compare Resonance strength first
• Then compare Dominant frequency
• Generate one report and share it

That gives you one clean answer quickly: did the mounting change reduce the vibration problem enough to keep it?