shielded vs. non-shielded in longer runs of cable

I'm in the process of rearranging my listening area so I can get as much equipment out of the middle of the speakers as I possibly can. The plan is to use longer single ended interconnects (ten feet) and locate the amp between the speakers. I've become attracted to the sound of minimally to non shielded interconnects but am concerned that going from one meter to three meter wires will create problems with hum, rfi, etc. I've not had any problems at all with the shorter unshielded length. (Our home is in a suburban environment without any obvious sources of electrical noise pollution.) Do any readers here that used non-shielded interconnects have experience with longer lengths?
I use Hero seven meters long to connect my preamp and amp.
The preamp is next to my listening position, and the amp is between the speakers. For the interconnect to wend its way around stuff between and be unobtrusive, it is seven meters long.
Hero is not 'shielded' wire' (it has insulation, but is not shielded from RFI EMI.)
I am in a major city near the center, and in an apt.
No problems at all.
And if you do find any issues, some bit of moving the wire can stop it. Even a short copper tube near the middle, with the wires running through it, and the copper tube grounded.
So I would say go for it. I am certain it will turn out fine.
Agreed with Elizabeth. I use Kimber PBJ, and custom made Silver in a similar braid as the Kimber, no hum or noise unless lying parallel to power cords. I prefer non-shielded when possible. My length of IC is shorter than Elizabeth's at 4 meters, but very quiet. Use shielded power cords and you should be fine. Be sure to not have dimmers in the room. If you use Class D amps, there may be more problems with noise.
I use AQ Sky, Cardas Golden Reference, Groneberg for shielded cables, and Silver custom braided ones, and they are all quiet. I am switching them all the time to compare and shielding has not been quieter. Enjoy, Jallen
Thanks for relating your experiences Elizabeth & Jallen. I ordered and installed a ten foot run of Luminous Audio Synchestra References and they work without any problems. No hum, no noise, dead quiet.