How to test speakers (sound system)?

Question

This question was asked to me in my recent interview for a junior QA position.

Any suggestions?

Answer 1

Your question is likely to be put on hold as it is opinion-based.

In general speakers can be tested from two general directions, functional and non-functional:

Functional test: you can test speakers based on its technical specifications, such as

• audio spectrum range, lowest frequency all the way to highest frequency.
• audio output angle, each speaker will have an area that has the most crispy quality.
• look for the sweet spot, a audio speaker system that consists of multiple speakers will produce a sweet spot.
• speaker configuration, how to configure this speaker system and do configurations take effect?

Non-functional test:

• can speakers operate without breaking easily, measure mean time between failure. you will need a "farm" of speakers and soak-test them in order to measure this MMTB.
• are speaker cables easy to plug and unplug, of a good ergonomic design?
• will a customer likely to damage speakers when unpacking? It happened to a company I used to work for, when unpacking our stations, stations got scratched badly.

Answer 2

This sounds like a generic 'how would you approach X' question.

So, what is important about speakers?

1. They reproduce sound
2. Volume can be changed
3. Sound quality is OK
4. No electric shorts while they receive current
5. Somewhat shock resistant
6. Keep working after receiving a peak in the signal

Etc.

For anything you cannot think of first-hand, read the speaker manual. To add to that, Google known speaker problems.

Now you have a bit of a start that can be used to write test cases.

But, before putting a lot of time into detailed test cases, speak to the speaker product owner to verify what you have up until now makes sense and to ask about priorities and known problem areas.

In a real world case you would probably want to talk to the product owner first, to see what the current state of the speaker project is. In an interview you first start to tell what your seat-of-the pants approach would be.

Answer 3

Integration test for a speaker + sound recording device system:

Play something on it, ideally some of clear sinus signals with non-rational frequency ratio.

Record the output with the sound recording devices.

Fourier-transform the recording to separate the speaker output.