Sorry to hear. Your dad was a long time member and a very nice guy.
Right off the bat I can say the center channel speaker level seems very high. The new hard floor sound reflection is also going to magnify that. Your listening volume in room is going to be heavily biased to the center channel’s direction and the other channels are going to seem far too quiet.
If you have an ipad I suggest downloading an spl measuring app. For basic system setup it doesnt have to be anything fancy (like audiotools by studio six digital). You are just looking to balance the net spl between each channel using the test tones in the receiver.
In the setup menu select manual speaker setup. Enter each channelsdjstance from the center viewing position and the speaker size. Select small for all with a sub crossover point of 80hz. Select “none” for rear channels if it is a 7.1 receiver.
Using the app, set measurement weighting to ‘C’ (dBC) . Beginning with the center channel, set the output trim level in the menu so your spl reading in room is 75db. If you have to go past +5-8 db or so use a setting of 65db instead. Repeat for all channels except subwoofer.
Turn the crossover/low pass dial on your subwoofer to full clockwise open (the crossover is set in the receiver menu). Turn the volume dial to 1/2 to start. Using the test tone in the menu, set the sub level +3 db hotter than your largest speaker. ie. If your fron left channel was set to 65db, set the sub to 68db.
Put on music you are familiar with and listen. If you are able to hear all the details in the music like guitar strings or breath on the singers voice you are good. If they are masked by too much bass turn the sub dial down a hair on the back of the sub. Test again. If too lean in the bass turn up a hair. Sub settings are extremely room and preference dependant so there really is no one size fits all answer. Placing the sub inside either the front left or right channel up front is a great idea if possible.
Popular setup tracks I use often are
Toto- Rosanna
Level 42- Something About You
Barenaked Ladies- Brian Wilson
Crash Test Dummies- God Shuffled his feet
Expect lots of great help. Welcome to the boards.
