I'm contemplating new bass solution for my system. The room is small, around 3x6 meters (10x20 feet), walls are rather thin and I would like not to bother neighbors but still get reasonably strong and deep bass at my listening position.
Design goals:
-Stereo (that is two cabs)
-Frequency response from 40(30 if possible)...300 Hz, where midrange takes over.
-Passive crossovers for the time being, bi-amping and active crossover later.
-More-or-less directional bass from ~30...100(preferably to ~200) Hz.
-SPL capabilities around 110 dB/m (of course, the more the merrier) for headroom. And for an occasional odd party now and then.
-Sensitivity over 90 dB/W/m.
-Size not much of an object.
-Cost is very much of an object.
-Good sounding, obviously.
-Simple construction since my tools and skills are limited.
So, after some research I've settled on U-frame and it's (pseudo)cardioid dispersion. But I have some questions:
1. Is directional bass in such small room viable? Has anyone got experience with any kind of directional bass solutions for home applications?
2. Any other simple solutions beside U-frame that do not use multiple speakers, amps and processing or sophisticated cabinets? What about regular dipoles (H-frames)?
3. Are there any guidelines (I couldn't find any) for the depth and stuffing amount for optimal performance or is it just trial-and error?
4. Drivers are the biggest problem - almost everything is just outrageously expensive here - Eminence Alpha 15 is over 114 € a piece
! I'm limited to ~100€ for drivers. I could maybe afford two of these, it makes 135€ with shipping. But I found some interesting dirt cheap car subs here, 35€ for two. I'm inclining to buy two pairs of them and use push-pull to reduce distortion. Opinions?
Thanks in advance,
T
Design goals:
-Stereo (that is two cabs)
-Frequency response from 40(30 if possible)...300 Hz, where midrange takes over.
-Passive crossovers for the time being, bi-amping and active crossover later.
-More-or-less directional bass from ~30...100(preferably to ~200) Hz.
-SPL capabilities around 110 dB/m (of course, the more the merrier) for headroom. And for an occasional odd party now and then.
-Sensitivity over 90 dB/W/m.
-Size not much of an object.
-Cost is very much of an object.
-Good sounding, obviously.
-Simple construction since my tools and skills are limited.
So, after some research I've settled on U-frame and it's (pseudo)cardioid dispersion. But I have some questions:
1. Is directional bass in such small room viable? Has anyone got experience with any kind of directional bass solutions for home applications?
2. Any other simple solutions beside U-frame that do not use multiple speakers, amps and processing or sophisticated cabinets? What about regular dipoles (H-frames)?
3. Are there any guidelines (I couldn't find any) for the depth and stuffing amount for optimal performance or is it just trial-and error?
4. Drivers are the biggest problem - almost everything is just outrageously expensive here - Eminence Alpha 15 is over 114 € a piece
! I'm limited to ~100€ for drivers. I could maybe afford two of these, it makes 135€ with shipping. But I found some interesting dirt cheap car subs here, 35€ for two. I'm inclining to buy two pairs of them and use push-pull to reduce distortion. Opinions?Thanks in advance,
T
those car subs in a Ripole?:
http://www.lautsprechershop.de/hifi/index_en.htm?/hifi/ripol_en.htm
http://www.lautsprechershop.de/hifi/index_en.htm?/hifi/ripol_en.htm
Stereo bass isnt possible in a living room, because the wavelengths are much to long. This said, directional bass is also not possible. Dipoles are more of a midrange solution, since all they offer in the bass range is a lower max output compared to the same driver in a different cabinet. One solution to have more bass for you and less for the neighbour is to listen nearfield - and i mean subwoofer directly behind the head kind of nearfield. This also helps with room modes alot. Put the sub behind your couch and you get the shaking for free
moray james - I've considered bass shakers, too. Sounds like fun, one day I might give it a try
PeteMcK - aren't ripoles pure subwoofers and trade efficiency for extension? I need frequency response up to 300 Hz and my mid-top modules are ~95 dB efficiency (Eminence Alpha 6 midrange and Celestion HF 50 horn in sealed enclosures). Since I'm using passive x-over at the moment, the bass modules should be around that sensitivity too.
MaVo, thanks for the input. As for stereo, think of it as not a sub-sat system but rather a modular 3-way speakers that are crossed over at higher frequencies. Also nearfield would only be possible if I used separate active subwoofer, for which I have no resources at the moment.
Anyways, this project depends on whether I manage to sell my current bass cabs or not (credit crunch and all the bad things going on at the same time). Since they are not "proper" bass speakers at all, just some poor cheap fullrangers (Visaton BG-20, "leftover" from previous project) terribly abused as a temporary solution, I would like to build real bass speakers anyway, and try something different - dipole and it's derivatives with their characteristic "no-box" sound being a very interesting alternative
PeteMcK - aren't ripoles pure subwoofers and trade efficiency for extension? I need frequency response up to 300 Hz and my mid-top modules are ~95 dB efficiency (Eminence Alpha 6 midrange and Celestion HF 50 horn in sealed enclosures). Since I'm using passive x-over at the moment, the bass modules should be around that sensitivity too.
MaVo, thanks for the input. As for stereo, think of it as not a sub-sat system but rather a modular 3-way speakers that are crossed over at higher frequencies. Also nearfield would only be possible if I used separate active subwoofer, for which I have no resources at the moment.
Anyways, this project depends on whether I manage to sell my current bass cabs or not (credit crunch and all the bad things going on at the same time). Since they are not "proper" bass speakers at all, just some poor cheap fullrangers (Visaton BG-20, "leftover" from previous project) terribly abused as a temporary solution, I would like to build real bass speakers anyway, and try something different - dipole and it's derivatives with their characteristic "no-box" sound being a very interesting alternative
I would like to resume this discussion as I am in a similar situation.
There are two paths that transmit sound to neighbours:
The second path is more difficult to reduce. An obvious solution is to locate the subwoofer close to the listener and turn it down. This way the listener is physically closer to the sound source than the neighbour, while sound pressure level drops at 6 dB for each doubling of distance. There is a practical limit on how small the listening distance can be.
It would be beneficial if the sound pressure level drops down faster. In a search I stumbled upon noise cancelling microphones, that do exactly that.
Electret Condenser Microphones | Product Spotlight | CUI Devices
Translated from microphones to subwoofers, it can be considered to be a dipole subwoofer, listened to (and this is important) in the near field. The listening distance is comparable to, or smaller than, the dipole spacing. A dipole can be thought of as a positive and a negative acoustic pressure source, spaced at some distance. Simplified: the listener is so close to one pressure source that he only hears this source, and no cancellation takes place from the out of phase second source. The neighbour (far field) hears both at the same level and full cancellation occurs.
A limitation is that the acoustic output of dipoles in the far field (neighbours) is determined by the phase shift between sound from the first and second source. If frequency increases, this phase shift also increases and less cancellation occurs at the neighbour. This is unwanted. Therefore the upper frequency for which this noise cancelling scheme is beneficial is limited. The upper frequency is related to the dipole spacing and a smaller spacing is better, though the spacing must be comparable to, or larger than, the listening distance.
I can imagine that a quadrupole possesses an even stronger effect, as it can be considered to be a dipole, constructed out of two dipole sources. A linear quadrupole can be constructed as two woofers in front of each other, driven in opposite polarity. This cancels cabinet shake as well. Sound pressure:
Any thoughts?
Ways to extend the upper frequency?
There are two paths that transmit sound to neighbours:
- Cabinet shake is transmitted by the floor to the floor and walls of the neighbour, where these radiate sound.
- (Airborne) sound passes through the wall.
The second path is more difficult to reduce. An obvious solution is to locate the subwoofer close to the listener and turn it down. This way the listener is physically closer to the sound source than the neighbour, while sound pressure level drops at 6 dB for each doubling of distance. There is a practical limit on how small the listening distance can be.
It would be beneficial if the sound pressure level drops down faster. In a search I stumbled upon noise cancelling microphones, that do exactly that.
https://www.cuidevices.com/product-spotlight/electret-condenser-microphones said:
Electret Condenser Microphones | Product Spotlight | CUI Devices
Translated from microphones to subwoofers, it can be considered to be a dipole subwoofer, listened to (and this is important) in the near field. The listening distance is comparable to, or smaller than, the dipole spacing. A dipole can be thought of as a positive and a negative acoustic pressure source, spaced at some distance. Simplified: the listener is so close to one pressure source that he only hears this source, and no cancellation takes place from the out of phase second source. The neighbour (far field) hears both at the same level and full cancellation occurs.
A limitation is that the acoustic output of dipoles in the far field (neighbours) is determined by the phase shift between sound from the first and second source. If frequency increases, this phase shift also increases and less cancellation occurs at the neighbour. This is unwanted. Therefore the upper frequency for which this noise cancelling scheme is beneficial is limited. The upper frequency is related to the dipole spacing and a smaller spacing is better, though the spacing must be comparable to, or larger than, the listening distance.
I can imagine that a quadrupole possesses an even stronger effect, as it can be considered to be a dipole, constructed out of two dipole sources. A linear quadrupole can be constructed as two woofers in front of each other, driven in opposite polarity. This cancels cabinet shake as well. Sound pressure:
Code:
+[woofer 1] - - [woofer 2] +Any thoughts?
Ways to extend the upper frequency?
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In the more typical situation it is just the bass that is annoying - 30 and 40 Hz goes right through walls like they are not there. At higher frequency the transmission is reduced. That seems to work for modest amounts of bass, and reasonable building construction. When I lived in a trailer growing up that was not the case - everything went through walls like they’re not there. When you can hear people talking in the next room you’re screwed. By the time I turned it down low enough for no one in the house to complain, the washing machine and TV were louder in my room than the stereo was. When the only tool you have is the 6dB per doubling - either move the speakers away or the neighbors away. Even if no one outright complained, telegraphing the fact that you have expensive stereo equipment in your apartment paints a big red target on your back.
I think that’s why high powered car stereos are so popular these days - it’s simply the last place on earth many people can go to make the 6dB per doubling truly effective.
Interesting. Everybody with family around and doing late-night listening has the same issues.
While in terms of SPL, bass transmission seems like the problem, the mid-range is far more audible and bothersome since it conveys meaning (except for one-note bass recordings and woofers which are the worst offenders).
I'd start with a low XO (130 Hz is low enough without harming spatial localization if sharp XO and clean speakers) so you can locate the sub over parts of the floor that are structurally the best foundation. And then de-couple the box from the floor.
BTW, a key fix is loudness compensation (almost any adjustable EQ tool will do) where you boost the low bass way up and so music sounds OK when played softly.
B.
While in terms of SPL, bass transmission seems like the problem, the mid-range is far more audible and bothersome since it conveys meaning (except for one-note bass recordings and woofers which are the worst offenders).
I'd start with a low XO (130 Hz is low enough without harming spatial localization if sharp XO and clean speakers) so you can locate the sub over parts of the floor that are structurally the best foundation. And then de-couple the box from the floor.
BTW, a key fix is loudness compensation (almost any adjustable EQ tool will do) where you boost the low bass way up and so music sounds OK when played softly.
B.
Headphones.
Being reasonable and realistic, there is NO way to contain bass from filtering through walls or floors.
My next door neighbor's home is seperated from me by a double-layer cinderblock firewall.
And bass, even at low levels, manages to travel into my home from his.
So.... headphones is the solution.
Being reasonable and realistic, there is NO way to contain bass from filtering through walls or floors.
My next door neighbor's home is seperated from me by a double-layer cinderblock firewall.
And bass, even at low levels, manages to travel into my home from his.
So.... headphones is the solution.
As mentioned previously, OB/dipole bass is very neighbour-friendly, it's even people-in-other-rooms-friendly.
I used to live in a basement below a restaurant and some neighbours who had big dance parties. By dance, I mean like proper dancing to swing music and the sort. At the time my system consisted of Visaton B200 open baffle speakers and a quad of Goldwood 1858 HFrame open baffles. No Eq.
In my apartment I could listen as loud as I liked, and none of my neighbors complained. Extension was good and worked well in my room. I lent them to the neighbours upstairs. They didn't like the lack of thump, as it was seemingly critical to thair dancing. What I did note tho, was that at no point in the night was the bass anywhere near as annoying as their computer subwoofer they usually used.
A friend from another audio forum lived in a Condo and had a neighbor who couldnt stand the bass from his speakers. They were floorstanders with 6.5" drivers, if memory serves correct. My theory was those Open Baffle were his ticket. While he does not use open baffles now, I recall his asking the neighbor if the music was bothering her and she didnt even know he was listening. Clearly the Open Baffles were less intrusive in the neighbors unit. This alone told me that OB can be a good solution if done right.
If a little thump is still desired, an exciter mounted to the seating, and isolated off the floor with some iso pads or something could get you a long way without the neighbors knocking. Ending up in an apartment of condo would be less than ideal, but it would present an opportunity to push boundaries of being loud without annoying neighbors.
In my apartment I could listen as loud as I liked, and none of my neighbors complained. Extension was good and worked well in my room. I lent them to the neighbours upstairs. They didn't like the lack of thump, as it was seemingly critical to thair dancing. What I did note tho, was that at no point in the night was the bass anywhere near as annoying as their computer subwoofer they usually used.
A friend from another audio forum lived in a Condo and had a neighbor who couldnt stand the bass from his speakers. They were floorstanders with 6.5" drivers, if memory serves correct. My theory was those Open Baffle were his ticket. While he does not use open baffles now, I recall his asking the neighbor if the music was bothering her and she didnt even know he was listening. Clearly the Open Baffles were less intrusive in the neighbors unit. This alone told me that OB can be a good solution if done right.
If a little thump is still desired, an exciter mounted to the seating, and isolated off the floor with some iso pads or something could get you a long way without the neighbors knocking. Ending up in an apartment of condo would be less than ideal, but it would present an opportunity to push boundaries of being loud without annoying neighbors.