You're saying "lowpass" but I think you mean "highpass"? It seems so from context.

16 hz output can make your house shake; 50 hz output loud enough will knock things off of shelves. In general your best bet is to get more sub(s) than you need and manage the volume to the level you find appropriate. You can also adjust the FR curve as well as how "hot" the subs are to suit your needs.

Cutting off lower frequencies entirely to sufficiently safeguard against vibrations will ruin the experience you're after and diminish the value of your sub investment.

 

Thanks, yes. Edited my post to clarify. Based on my goals, would you recommend upgrading to larger subs or simply getting two more MartinLogan Dynamo 800X?

 

In my experience the house shaking comes from the lowest frequencies. But the higher frequencies can also cause rattling and buzzing during music for example.

With that said, the best way to deal with keeping bass from shaking the house is going to be during the construction phase. In my opinion you're wasting your money if you buy a capable sub and then neuter it with a high pass filter to remove the lower frequencies. I understand that's kind of a subjective perspective but at the same time why spend money on a sub that can player lower and louder just to remove that with a filter?

Anyways, even if you remove the lower frequencies with a high pass, unless your room is constructed specifically to help reduce sound transmission to other parts of the house you're still going to have a problem unfortunately.

 

In my experience the house shaking comes from the lowest frequencies. But the higher frequencies can also cause rattling and buzzing during music for example.

With that said, the best way to deal with keeping bass from shaking the house is going to be during the construction phase. In my opinion you're wasting your money if you buy a capable sub and then neuter it with a high pass filter to remove the lower frequencies. I understand that's kind of a subjective perspective but at the same time why spend money on a sub that can player lower and louder just to remove that with a filter?

Anyways, even if you remove the lower frequencies with a high pass, unless your room is constructed specifically to help reduce sound transmission to other parts of the house you're still going to have a problem unfortunately.

I don't disagree, but are there subs that deliver the higher volume output without the lower frequencies? Seems like you're usually purchasing them in combination, when you go for quality -- which isn't necessarily a bad thing, just not quite what I'm after, I think

 

Every thing in the universe has a resonant frequency,

The planet earth is around 7Hz and your eyeballs is around 17 to 18Hz. Snce houses are all different, there is not muc of a point taking a guess. My house, thanks to high ground water siits on pillings so the hardwood foors are suspended above terra firma--pretty cool but testing indicates one bedroom will resonate at 10.6Hz--my wife woke up when I was doing sweeps.

Reaiistically, you won't be able to stop bass waves being heard on the second floor--they travel through all surfaces that contain mass and conventional building techniques do little to adress this. Dr. Earl Geddes has a book on thiis and he went to great lengths to stop bass waves like floating unequal walls, muffled HVAC, different wall materials and so on. Very expenive and time consuming but it can be done.

Think of what a subwoofer actuallyis-an air pump that attempts to pressurize your room with rapidly fluctuating positive and negative air pressure waves. This is why studios and such use "floatig walls" and one studio I read about was cconstructed on top of giant springs to prevent vibration from coming in and going out.

The best thing you can do is some sub bass sweeps, find anything vibratng (wall boards, HVAC vents etc.) and take care of those problems as the appear. All the stuff on the second floor will be susceptible to shaking as it is above ground zero so check that floor to find any loose wall boards, vents, trim or whatever that wants to join in on the subwoofer line dance....

I built a pair of push-pull slot loaded subs that I could balance coins on the boxes at full tilt. The box did not vibrate because the two drivers are in balance but the sound pressure waves had stuff falling off bookshelves, it shook my house and my neighbor's house. Oooops! My neighbor thought it was cool but she is a rocker from way back and most people don't want to join in the party next door. At least the sub boxes don't vibrate but that bass can be heard for quite a distance....just the nature of very, very long sound pressure waves.

If you want to fake it, get some of those shaker things on the couch so you can flip the subs off and do the shake, rattle and roll if the family is asleep. Maybe a near field sub up close can help with the bass shakers when normal people have called it a night.

Good luck, we all can't live in a custom built underground bassment/bunker like BassThatHz--it is a pain to track everything down that resonates but such is the game.

 

Every thing in the universe has a resonant frequency,

I was going to paste the same thing. The waves will travel up the walls and what frequencies are amplified depends on materials and construction of the walls. You can try to dampen the walls, but it's almost certainly more effort than it's worth.

 

Hi,

It's a combination of low-frequencies and high volume levels that causes vibrations in adjacent structures. Slam or chest punch sensations occur from high volume levels in about the 50-100Hz range. Most people seem to feel the strongest sensations in about the mid-60Hz range. Reverberation from suspended wood floors and drywall (sheetrock) walls and ceilings seem to occur below about 25Hz, and perhaps even below 20Hz, depending on the thickness and durability of the construction materials.

The concrete floor of your basement (laid on top of soil) will be pretty inert, so you won't have to worry about transferred vibrations from that. You may want to experiment with moving your subs just slightly away from boundary walls if vibrations in adjacent walls are ever a problem. Proximity is a factor in secondary reverberation.

There will be several things you can do besides setting a high-pass filter for your subs, when people are asleep upstairs, if floor reverberations in the rooms above or low-frequency SPL ever become a problem. The simplest would probably just be to turn down the volume of your subs a little if the bass interferes with people sleeping in rooms on the second floor. It may not ever be a problem! Denon/Marantz AVR's have a feature called Low-Frequency Containment, with several setting levels, that will attenuate the lowest frequencies on the fly with your AVR remote. Dynamic Volume is another D/M setting to prevent loud noises from disturbing others. Other AVR brands probably have similar features.

Personally, I wouldn't worry about this too much right now. It may not ever be a problem to begin with, and if it ever becomes one, you will have many tools available to resolve it during important sleep times. I like your idea to try something such as dual SB-3000's. They are very strong in the mid-bass range, and your small room size will give them a lot of help below about 25Hz. I also like the idea of trying ported PB-3000's. There would be a 45-day free trial period to allow you to test them.

Again there are a lot of things you can do to diminish your low-frequency SPL and TR (tactile response). But, the inherent capabilities of the subs is a limitation in how much of those things you can get when you really want to cut loose.

Regards,
Mike

 

Hi,

It's a combination of low-frequencies and high volume levels that causes vibrations in adjacent structures. Slam or chest punch sensations occur from high volume levels in about the 50-100Hz range. Most people seem to feel the strongest sensations in about the mid-60Hz range. Reverberation from suspended wood floors and drywall (sheetrock) walls and ceilings seem to occur below about 25Hz, and perhaps even below 20Hz, depending on the thickness and durability of the construction materials.

The concrete floor of your basement (laid on top of soil) will be pretty inert, so you won't have to worry about transferred vibrations from that. You may want to experiment with moving your subs just slightly away from boundary walls if vibrations in adjacent walls are ever a problem. Proximity is a factor in secondary reverberation.

There will be several things you can do besides setting a high-pass filter for your subs, when people are asleep upstairs, if floor reverberations in the rooms above or low-frequency SPL ever become a problem. The simplest would probably just be to turn down the volume of your subs a little if the bass interferes with people sleeping in rooms on the second floor. It may not ever be a problem! Denon/Marantz AVR's have a feature called Low-Frequency Containment, with several setting levels, that will attenuate the lowest frequencies on the fly with your AVR remote. Dynamic Volume is another D/M setting to prevent loud noises from disturbing others. Other AVR brands probably have similar features.

Personally, I wouldn't worry about this too much right now. It may not ever be a problem to begin with, and if it ever becomes one, you will have many tools available to resolve it during important sleep times. I like your idea to try something such as dual SB-3000's. They are very strong in the mid-bass range, and your small room size will give them a lot of help below about 25Hz. I also like the idea of trying ported PB-3000's. There would be a 45-day free trial period to allow you to test them.

Again there are a lot of things you can do to diminish your low-frequency SPL and TR (tactile response). But, the inherent capabilities of the subs is a limitation in how much of those things you can get when you really want to cut loose.

Regards,
Mike

I have a Denon 4700 and I've been experimenting with Audyssey LFC recently. This is what it says when you highlight it:

"Dynamically monitors the low frequencies and prevents them from traveling through walls."

Sounds like exactly what the OP is looking for.

When I first got my PSA TV2112 I hadn't really considered the fact that the room is right underneath the bedroom. It was never an issue before even though I had three 12-in subs going.

One day I was taking a nap and I had a dream about a tornado ripping up my house with a deafening noise... and then I woke up in panic because the whole room was vibrating and shaking to giant booming sounds.

I jumped up and ran downstairs to find my wife and son watching Ford vs Ferrari at -10. Nothing we don't do almost everyday....Just one of the race scenes was all. I guess there was a crash or something but holy crap! That's when I started looking into the low frequency containment feature of my 4700.

So now if someone is sleeping and we want to watch a movie all loud we can turn on the LFC and it seems to do a good job of knocking down whatever is blasting through the walls. Hasn't woken up anybody since. I run it at 4.

Yes, it will neuter the awesome sub that you bought so that someone can get a little bit of rest... But there is still a good amount of bass and it's much better than just turning off the sub or unplugging it or whatever we used to do.

Can always turn it back off when people are up and you want to scramble your insides again.

 

Go for the extra performance and back off if you need to. You're just going to have to experiment. There's no way to predict this particular effect for your situation, plus the point where things go from "perceptible" to "annoying" is different for everyone. It would also depend on how much ambient noise there is upstairs. Actually being on a bed would lessen the "feel" of any vibrations a bit. It would act as an isolation device.

 

I have 4 18" sealed subs. 2 in the front of the room, 2 directly behind the couch firing straight into the back of the couch. These 2 nearfield subs make all the difference for what you are looking for.

I live in 1 story rambler with my theater in the basement. I can hear and feel some great bass with the kids sleeping upstairs because with the subs so close I don't need to pressurize the whole room.

I would definitely recommend looking into adding nearfield subs.

 

At your listening levels, I wouldn't worry about it; close doors and enjoy. If there are complaints, you could add shakers or subs closer to your seat. Going full 90dB+ peaks might cause the need for added steps.

 

At your listening levels, I would worry about it; close doors and enjoy. If there are complaints, you could add shakers or subs closer to your seat. Going full 90dB+ peaks might cause the need for added steps.

Typo? I think you meant... wouldn't?

 

If your on a slab in the basement, Any bass you hear and feel will shake twice as much upstairs.
I think investing in a hover boss set up or some other kind of bass shaker and a set of subs would be the route I'd take.
That way you can bass out when everyone's gone and still feel bass when you have to be quiet.

 

Really depends on the size and construction of the room/house.

I'm running four 18" (dual PSA V3611s) and four 21" Devastators in ~6,500 cubic feet and while I can and have easily split, cracked, and separated the drywall, you really can't hear much from outside of the house. The vast majority of the house is stone or brick and the theater is upstairs. There's a little vibration in the master but the wife doesn't complain, closing the solid core door pretty much mutes it all.

You'll be fine with little SVSs.

 

how's your hearing?

 

Bring the subs closer to your MLP. If your sub needs to shake the entire room for the desired response level, then it will shake the house as well. If you are sitting right next to the sub, then you can turn down the gain and get some good tactile output. As stated above, you can also cut out the low frequencies with EQ and use bass shakers.