Brave Church have a very good video on Revelation chapter six which is well worth watching. It lasts just under an hour.
Jeff Scahwarzentraub speaks very clearly and in an enjoyable manner. I like his humble yet honest style. He covers the whole chapter well and he speaks from a Pre-Wrath point of view that I thoroughly agree with.
The video can be found here: https://tinyurl.com/pybnhefd