I am observing things in the 45 that my 25 did exhibit and would like your thoughts. Location, cables and so forth are exactly the same as the 25. It was a direct swap out.
Power on with 25 had a very solid relay click right after power up and power down. The 45 does not have this click or any click just a momentary low level sounding buzz that last about a second that tapers down to no buzz, sound is coming from the unit itself.
Upon power up there is a low level what sounds almost like a power hum coming from the tweeters on the Polks. I have to place my ears about 4" from tweeters to heard it. Does not get louder but is always present even if the 45 is only thing powered on.
Upon power off there is a very slight thump and the peak meter jumps to .01 then back to 0.
These observations may be normal for the 45 do not know but since my 25 not not do any of this I thought I would ask people here who may own or have owned a TFM-45.
Other than these observations the 45 and 25 sound the same, great.