BlankAn "S3" speaker in the P3 cabinet -with- the already-designed AF1 audio filter integrated into the box would meet the needs of those wanting an audio filter. Something along the lines of the external speaker for the Yaesu FT-1000D / FT-990's, for example. Ken Kopp - K0PP ElecraftCovers at rfwave.net http://tinyurl.com/7lm3m5