Read this if you have time - its basically about my findings by using an amps internal test tones and a setup disc (like DVD Essen or AVIA) that calibrate from the source. I was kindly offered a lend of DVD Essentials set-up disc (Thanks to Matt Horne) so that I could calibrate all my speaker levels to exactly the same. At current, I am not setting everything to reference (75db) level as if I do I have to lower my front three speaker levels by a whopping -7/8db as I use an Arcam Power amp for front three and the Denon looks after the rest. Obviously the Arcam or the Denons Pre-amp stage makes the signal a lot more powerful then the Denon internal amplifiers! Using DVD Essentials (or no doubt AVIA) and an SPL meter has really made a positive impact on my surround sound system. It has just proven to me that the internal test tones do not really work as effectively at aligning your system levels in comparison to using test tones through the source; namely your DVD player. For quite some time, I have felt that the my rears speakers were over powering and one sided when playing surround sound DVD's. Also, the centre channel produced quieter vocals. However, the internal Denon test tones all measured 75db so I thought the problem was down to appalling room acoustics. I was just about to spend £250 on a thick wool 300 x 200 rug and place objects on the back wall. Lucky for me I used the DVD Essentials disc beforehand and may I say, categorically, that 80% of these problems have now disappeared. The rears are no longer over powering and one-sided and the steering from the front to back is pretty much fantasticly improved. The low audibility speech issues have also ironed themselves out to a high degree and watching films such as We Were Soldiers at lower levels produces a far easier to understand dialogue then before. The lesson to be learnt here is that setting test tones from the amplifier simply isnt good enough to obtain a true effect of enveloping surround sound from your speakers. Also, wrongly powered speakers can over power certain parts of the sound causing a loss of effect (or dialogue quality) in others. The rule is simple really because, if you think about it, you really should align the speaker levels from the source you are playing from rather then the amplifier which is the mid way part in the process of source - amp - speakers. Trust me. The difference has been really noticeable and I would recommend anyone using there amps internal test tones to recalibrate them with either of the DVD discs mentioned earlier or some kind of well made test tone DVD.