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Discussion Starter #1
since I can not post links or pictures, you just have to use your imagination on this one..

The most normal problem with just one SUB and its installation, is the level and frequency
and phase response is NOT at all near same for all people in the room.
ok I could adjust it so it is near perfect for one person (me in my favorite seat)
but the other person near the sub experiance near death levels,
and the one in the far corner hear and feel nothing.

how to solve this..
I have been thinking about this for a long time, simply open the sofa, remove bottom cover,
mount thick and stable wood plates, whole bottom.
add a number of large bass drivers, adjust frequency and phase and level.

The first prototype was made last night :)
I simply installed two 10 inch BUMPERS (from USA FL)
amazing result !!
the power level and low frequency capeabilities are amazing, very little power is now needed,
due to very direct and short distance from the speaker to my whole body,
more info later
 

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Discussion Starter #2
I have ordered a bunch of 12" drivers
since that size is simply the minimum size to make me feel happy,
the last night 10" testers was just whay I could dig up for free, before the real speaker show up,
cant wait, know the feeling ?

I expect to use AntiMode for correction, but my first tests actually showed very little need for it,
so I wait with purchase until all speakers are installed and tested.

I could feel a very little level change from one seat to another,
my sofa actually consist of two joined 3 seaters each,
and each of those I put in 2 x 12", so a total of 4 speakers are needed.

I only made one sofa last night, the two 10" speakers are mounted under the most left and
most right person, the mittle person have no but speaker,
that seat have just a little bit weaker but kick level :)
 

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Discussion Starter #3

Here is my cinema corner.


and my projector in sound prof case


The first version of the sofa sub, simply uses 2 x 10" subs, lets see what next version is :)
 

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Elite Shackster
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Believe it or not, you will be loosing quite a bit of output if the subs arent mounted in a cabinet of optimum size. You could easily keep this idea, but make the cabinet inside the sofa. I know you will feel the effects well like this, but its not the best it can be. The reason little power is needed is as much to do with the effective cabinet volume being quite large, as much as it is to do with being close to the drivers.

I love the thinking though, and the 12's should be a hoot. How many do you plan to use?
 

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Believe it or not, you will be loosing quite a bit of output if the subs arent mounted in a cabinet of optimum size.
I agree.

What you've created is more of a rumble seat as opposed to a proper subwoofer. Your couch, as implemented, doesn't really qualify as a sealed enclosure. Moonfly is correct in that you may see better performance building a sealed enclosure(s) into your couch structure.

Looks like a fun project either way.
 

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Discussion Starter #6
thanks alot for your input,
well I have no actuall need for a sub, when it comes to the sound for normal hifi usage :)
since my front system is really good down to 40Hz -1.5dB
But I like the "feel" of really low frequency sounds/bass.
There is not real easy fix to make a closed or ported case under the sofa,
and point the speaker up for but kick, ok got the idea,
but you see on the pictures the bottom side of the sofa is soft and spring flexible
I am affaright something may be hit the speakers if a kit of mine jumps in the sofa.
I did alot of testing today, also tried much more power, and adjustes the frequency ranges a bit,
my conclutions so far, the two 10" are too small/weak for the ultra low frequency band i love the most,
ok listen to Justin Timberlake What goes arround, the 3 low notes in the end of that song after 5.40 !!
they are now finally all 3 at SAME level, this makes me happy.
I dont know if you like that kind of music, dont really matter much, just check it out anyway for its hifidelity.
I have with the two ten'ers a good flat response from 30hz and way up (but cut it at 60)
but it is getting weak at 18 Hz and close to nothing at 10 Hz
when I compensate for this I hammer the speakers to their stops way too easy,
my amp is offcourse sized and ready to kill what ever :)

so I have 4pcs 12" speakers on their way,
I tried to push the supplier to inform a delivery time, but no info so far..

I expect to put 2 x 12" in each sofa, and trim the level using digital eq,
and just have plenty of power headroom for the adjustments,
so I dont need to think too much about box design, and just use brute power.

I also tried a bit cinema material today, ok at ref level earthquakes and similar sounds now kicks so hard
you are sure you are right in one !
so I assume I need to trim the level alot down.. ya right (NOT going to happen)
 

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I also think it is an awesome idea but some better implementation of the subs would net much more satisfying results.:T
 

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Discussion Starter #8
better result ?
define better ?
harder to make ? more complex hardware ? newer finished ?
higher efficiency ? more flat uncompensated responce = less compensation needed

But what if, easier to make, cheaper to make, faster to make,
add tons of after compensation to make it work,
is exactly what I want, to solve this as fast and as easy as possible,
that is maybe better for me :)
hehe, but offcourse I am here to hear your inputs, learn new tricks,
share ideas, not to claim my own perfection.
 

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Discussion Starter #9

Compleetly uncompensated, directly under the speaker.


Still uncompensated, where you have your feet on the floor

offcourse not perfect, but a good beginning :)
remember I dont want this to play normal bas range,
but only the lowest and most hardcore frequencies..
 

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Elite Shackster
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better result ?
define better ?
harder to make ? more complex hardware ? newer finished ?
higher efficiency ? more flat uncompensated responce = less compensation needed

But what if, easier to make, cheaper to make, faster to make,
add tons of after compensation to make it work,
is exactly what I want, to solve this as fast and as easy as possible,
that is maybe better for me :)
hehe, but offcourse I am here to hear your inputs, learn new tricks,
share ideas, not to claim my own perfection.
A larger enclosure is more efficient, while a smaller one will need more power, especially sealed. Thing is, with no solid cabinet, when the driver moves the sides of the sofa will flap about which is where you will lose output. If you make the subs so they are mounted in cabs, even ported ones, you will gain further output, although you may lose that feeling a touch. With a sealed cabinet though, you will hear the subs more, which I'm guess you actually dont want, and you will likely feel them less, which I'm guess you may also not want. At the end of the day, you need to be happy, even if your design is a little unconventional.

Why not just use a buttkicker?
this is a pretty good idea, you will feel low end bass right down to 5hz no problem, something even your 12's wont be able to match.
 

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Discussion Starter #12
butkickers are very expensive, and very hard to get here,
and they need the sofa to be decoubled from the floor,
else the whole house will shake along too.
and I still need my regular sub to be in the way, my point was to get rid of it, if possible.
and integrate it all into the unused hidden space under the sofa, and at the same time vibrate
the persons directly.

Your are right. the way it is now, I hear almost nothing from it,
but feel it all, ok so far only down to 20 Hz,
I think the coubling to butt versus air is a bit too much actually :)
So closing the case alot more, will change that factor, but it is very hard to do
with this approch, I think alot about how to get it all at the same time,
and still easy fast and cheap and nothing in the way, I want to clean up the room too :)

What kind of movie material take advantage of the full range and capeabilities of the LFE ?
I mean the LFE track is designed to be able to deliver from 2Hz to 120Hz
so where can I see and hear and feel anything using the 2-20 Hz range ???
 

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Elite Shackster
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Search the forum for the movies with deep bass section. There are a few films with very deep bass, Pulse being one (15hz) and Black Hawk Down is a well known one (8hz). Apollo 13 also has some very low bass by all accounts in the sub 10hz region during the rocket launch scene. Your small 10" drivers wont like trying to produce sub 20hz material though.

If you use a driver in free air, you wont hear anything from it, put it in a cab and you will. The smaller the cab them more you hear it. I would at least try build some kind of cabinet unless your only after tactile effect.
 

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Discussion Starter #15
thanks alot about the film hints, when it comes to feel vs sound,
what can you hear and what can you feel ??
the ears also have a roll off
 

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20hz is considered the limit of human hearing. You can 'detect' frequencies below this, but they become a bit of a mix of feeling and hearing which are mostly interpreted as feeling. Frequencies this low though require a lot of air to be moved for you to feel them effectively, something small drivers will always find hard to do convincingly. That said, the way you are doing it is about as good as it will get, you have basically turned your drivers into bass shakers.
 

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Discussion Starter #17
so the most uptimal must be from 20 and up, make sound not vibrations
under 20 make less air sound, more vibrations, so you feel it not hear it,
this way we can make a system that can handle from 2Hz (LFE lowest possible)
 

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In that cofiguration the subs would actually be performing like their in a large aperiodic vented enclosure which the rolloff is somewhere between a sealed sub, and a vented one. Estimating the size of enclosure its acting like would be quite difficult, but the measurements will tell the truth. Have you taken a measurement with the mic on a stand at ear height in the seating positions? That's the measurements I'd like to see.
 

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Discussion Starter #20
I dont hear really low frequency vibrations with my ears, but feel them quite fine with the butt :)

as it is right now, even 30-60 hz is not really heard in ear position, if you stand up
it allmost all go away, this is almost fine,
I think this ratio could be changed by making better to air coubling
and less butt kick, so this is some thing I like to improve
and also try some larger woofers with much lower freq handeling,
I am now again out on the marked for some, my supplier refused to deliver the wanted units.
so actually I dont know at all what size or type to go for at this moment,
suggestions are welcome, I prefer them to be in the 100-300 $ range
since I guess I need 4 of them
 
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