Sound-absorbing spikes, also known as acoustic spikes or isolation spikes, are designed to decouple audio equipment from the surface it's sitting on, reducing vibrations and improving sound clarity. They are typically used in high-end audio systems, recording studios, and other environments where minimizing vibrations and resonances is crucial.

In a quiet room, installing sound-absorbing spikes can still be beneficial if you have audio equipment that is sensitive to vibrations. Even in a quiet environment, small amounts of vibration can affect the performance of your audio gear. The spikes can help to isolate the equipment from these vibrations, leading to a clearer and more accurate sound reproduction.

However, whether it's "okay" to install them depends on several factors:

1. **Equipment Sensitivity**: If your audio components are particularly sensitive to vibrations, installing spikes can be very helpful.

2. **Room Acoustics**: The acoustics of the room play a significant role. If the room has a lot of resonance or echo, spikes can help, but you might also need other acoustic treatments like bass traps, diffusers, or absorptive panels.

3. **Budget and Aesthetic Preferences**: Sound-absorbing spikes can be an investment, so consider whether the improvement they provide justifies the cost. Additionally, some people may not like the look of spikes and prefer other solutions.

4. **Installation Difficulty**: Installing spikes requires careful placement and possibly some adjustments to ensure they work effectively without causing other issues (like instability).

5. **Alternative Solutions**: There are other methods to reduce vibrations, such as using anti-vibration mats, stands, or platforms, which might be more suitable or cost-effective depending on your setup.

In summary, while it's not strictly necessary to install sound-absorbing spikes in a quiet room, they can certainly enhance the audio experience by further reducing vibrations and improving sound quality. It's essential to assess your specific needs and the characteristics of your room and equipment before making a decision.