I am using DH67CL With i5-2500k. I was using Bios "BLH6710H.86A.0146.EB" intel remove this version saying issue with the boot up. And I am now using previous version "BLH6710H.86A.0132.EB". I am Experiencing less audio quality for the same audio driver "126.96.36.19926" ever since. Does anybody faces the same issue and how to improve the audio quality (I am using 5.1 sound system).
To answer your question, the BIOS version 0132 release notes shows fixes to some audio issues related to HDMI and is not supposed to reduce audio quality at any point. What do you exactly mean by "less audio quality"? Please provide a detailed description of the issue in order to provide accurate troubleshooting and assistance.
The boot up problem was only evident with some boards if attempting to update from a BIOS version older than 0132. If you never experieced this problem, you should be fine to update (again) to 0146 (using the same file you used last time from your hard disk drive or whatever media you saved it to). If you reverted you would have needed to use the recovery method to be able to do it properly as 0146 incorporated an Intel ME update from the previous version. Have a careful read of the instructions about BIOS updating and reversion and you'll see what I mean. Also remember that the 0146 update was a special 2-step process needing the second flash to be done using the recovery method anyway (ie you had to flash the same file twice).