Down-firing subs and downstairs neighbors

Hello Audiogoners,

I am looking at subwoofers for 2 channel music. I will soon be moving into the 2nd floor of an older wooden house, with neighbors below me. I don’t want to drive my new neighbors crazy.

It seems intuitive that a downward-firing sub would penetrate the floor more than a forward-firing one--but is that true? Also, can you do things to mitigate, like put a down-firing sub on a piece of stone, or a particular material?

Any suggestions/info much appreciated
Your neighbors will want to kill you. I've been down that road. In fact, even with a slab of granite under a front-firing sub that I bought to replace the down-firing sub that nearly got me evicted, the sound traveled down the corner of the building right into their living room. Subs and apartments don't mix. What I ended up doing -- and what solved the problem -- was to switch to full-range speakers. If you want to go deeper than 35Hz or so, tough a house.
First question, how much insulation will be between your floor and your neighbor's ceiling (if it's none, which is probable the case, you asking for trouble, by putting in a subwoofer)? Second question, how loud to you like to listen to your music and at what time of day? Probably the biggest problem will the bass from your subwoofers bleeding into your neighbor's apartment, and it really doesn't matter whether the subwoofer is down-firing or forward-firing. And there is "no way" to stop this "sound bleed" unless you're willing to pull up your flooring and acoustically isolate and/or dampen the space between your floor and your neighbor's ceiling. If I was me living in such a situation, I would stick with stand-mounted monitors, and wait until I had a place where I could use a sub-woofer without bothering the neighbors. Other than that, once you get moved in, I would borrow a sub-woofer and test your system to see how much bass "sound bleed" goes into your downstair neighbor's apartment and what THEIR tolerance level might be. Remember if YOUR MUSIC is bleeding into their apartment, it's your responsibily to solve the problem.

PS: You signed the lease on the place, yet?
1. Subwoofer placement. (stay away from the corners. Try mid-front or mid-side wall). The goal is to get the smoothest respond without boominess and overloading the room.

2. Use of bass traps in all corners and sub_base like the one Auralex sells.

3. Seal all cracks, gaps etc. Use exp.foam to fill the outlet boxes, use caps to cover unused outlets. Get heavy carpet with extra thick padding.

4. Set you sub low to pickup only the lowest frequencies. Lower volume if nessesary.

Or, find another place that is more suitable for this hobby.

Full range speakers won't get you anywere. Low bass is not directional. Monitors might be a better choice for you. Use sub for referance listing sessions and turn it off for late hour listining.