There are several steps you can take to minimize the effects of room acoustics on your DIY speaker design:

1. Use proper speaker placement: Try to place your speakers at least 3 feet away from walls and corners, and aim them slightly towards the listening position.
2. Treat the room acoustics: Use sound-absorbing materials, such as acoustic panels, bass traps, and diffusers, to improve the acoustics of the room.
3. Use a crossover: A crossover is an electronic circuit that divides the audio signal into separate frequency bands and sends each band to the appropriate speaker or driver. This can help to reduce the load on each speaker and improve the overall sound quality.
4. Use an equalizer: An equalizer is a device that allows you to adjust the levels of specific frequency bands in the audio signal. This can help to compensate for any room resonances or standing waves that may be affecting the sound quality.
5. Experiment with speaker placement: Try moving the speakers around the room and listen to how the sound changes. You may find that certain placements sound better than others.
6. Use high-quality speakers: High-quality speakers with good frequency response and low distortion will generally sound better in any room and be less affected by room acoustics.