Speaker cables under floorboards - a good or bad idea?


Hi all…. Relatively inexperienced about the dos an don’ts of how to run speaker cables from the amp to the speakers for optimum performance. Am using Supra Classic 4 cables - 5 metre runs - from a Lyngdorf TDAI 2200 to a pair of Quad ESL 57s. The Supra cables are currently sitting on the floorboards for their runs from the amp to the ESLs. Am content with the way it all sounds, if not with the way it looks! The floor itself is suspended timber with a joist depth of 6 inches under the floorboards. And over the coming weeks, I will be lifting the boards to fit rockwool sound insulation in the underfloor cavities (to reduce the sound levels reaching the room beneath mine). ….So, I thought I would take the opportunity, while the boards are up, to run the Supra speaker cables under the boards. To be effective, the rockwool needs to be dense, and fill the underfloor cavities as tightly as possible. This means that, if I run the Supra cables under the floor boards, for most of their runs, they will be in intimate contact with dense rockwool. … Given that a lot of folk have found that the best way to run speaker cable is on cable elevators - i.e. as little contact with anything as possible - is the plan wise? I could try it and see/hear for myself of course, but obviously want to avoid taking the boards up - again - if the SQ is compromised.  Any thoughts - or experience - would be most welcome.
osborn
Horrible idea. Worst for sound quality, won't hardly reduce noise transmission. Speakers on springs, cables on elevators. Done.
I would get a preamp + amp combo that supported long runs of XLR cables. You could stuff those cables under the floor board easier (with respect to sound quality) than the speaker cable. I know the professional grade Benchmark StarQuad XLR that I use can work in your scenario well for very long runs. I think my cables are 15 feet or 25 feet runs, it sounds excellent. Some smart guys on A’gon told me to makes sure my preamp-amp combo supports the AES48 XLR standard for long runs. I contacted the manufactures of gear I was interested in to ask about AES48 before I bought. For ex. Benchmark and W4S supported it and Luxman did not.

https://www.aes.org/publications/standards/search.cfm?docID=44

I know the Lyndorf 3400 can support XLR not sure about your 2200. You can also use the 3400 as a preamp only and output to different amps via XLR, I have done this in a demo of the 3400.

BTW - i though the preamp + DAC of the 3400 was really good. The amp section was not something I liked. When I went to an external amp via XLR the system sounded great. That was a $15K external amp but I think a Purifi amp from March Audio for under $2K would likely yield the same results.
Seriously, horrible idea. To give some idea, I tried wrapping my cables with very thin gauge wire to see it it would control vibration. As mahgister pointed out, hold them while playing music its shocking how much they vibrate. Just this thin wire wrapped around them devastated dynamics and detail, sucking unbelievable life out of the music. Packing cables tight in rock wool, when you hear how bad it is, don't try and say nobody tried to warn you. Springs under speakers will improve sound and reduce transmission. Cable elevators will improve sound, even more if used with my rubber band tweak. https://systems.audiogon.com/systems/8367#&gid=1&pid=10