Considering a DIY horn sub bed frame...

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I just moved into an apartment that I will be in for the next year and need a bed frame. I have considered just buying an ikea frame but I am considering making a cheap plywood frame for my bed that is also a horn subwoofer. My thinking is that for the price of a frame I can build a cool project. The max size of the frame would be 53"X76" and should probably be not much thicker then the sub used. I would have to do this very cheap so I would be using the cheapest driver I can find (unless someone has one to donate) and any amp I can find to use which will be low passed by the computer it will be connected to. If I do decide to build this the side of the enclosure that is facing the floor will not have a board, it will use the carpeted floor to seal the enclosure. I don't need huge bass but I want it to be listenable. Normally I would not go with a horn for bass but with the size of my enclosure being able to be so large I figured it might be a fun thing to try. The only other horn or I should say horn like enclosure I have built is the wicked one on the decware site. That sub was unreal for the 2 8" I put it in. I thought about scaling the design up but I would like to keep costs down by only using one sub. Do you guys think this is a worthwhile endeavor? Are there any plans online for something like this that has been done before (I have yet to find any)? Any design or part recommendations?
 
DJNUBZ said:
If I do decide to build this the side of the enclosure that is facing the floor will not have a board, it will use the carpeted floor to seal the enclosure. I don't need huge bass but I want it to be listenable.


I don't think you will get acceptable results like that. You should seal the other side.
 
Huh! I thought that was Bert Doppenberg's first all horn system. Anyway, isn't qi's B@$3 WC all folded up inside his bed frame? What about a TH with a high Q driver to keep the HF BW < 80 - 100 Hz?

GM
 
Personally I've got to disagree with the punisher suggestion as the only plots I've seen of it looked nowhere near subwoofer duty. (60 hz ?)

Maybe as a 2 way sub with a large ebs below or even a 6th order BP but not on its own.

However maybe the flare extender could change it a lot ?

Personally I'd be looking at either TL's or tapped horns, neither of which I'm any good at designing 🙁


Rob.
 
Instead of the Punisher, the Stepped Horn, using the same driver (and from the same designer) is much more suited for home use. The Punisher is basically ment for >40 Hz, in stacks of 4 or more. The Stepped horn will get a solid 30 Hz on it's own.

http://www.speakerstore.nl/index.php?l=nl&pg=11&c=61

It's longest side is 67", other sides are about 15" each.

From the tapped horns I build so far, nice results for home use are easy to achieve and easy to design, using drivers with Qts between 0.3 and 0.4 (fs ~1/2 octave above cuttoff) and this build model: http://img155.imagevenue.com/img.php?image=05613_Tapped_horn_Hornresp_122_1037lo.JPG
With L12 and L34 ~same length (10 -20").

Johan
 
DJNUBZ,

The carpet won't seal enough to work,I have tried it.

A large bass horn in an apartment could be a problem with the neighbors...

Anyway,here's a plan for a 31 hz horn using the MCM-55-2421 8" driver,$35 from mcmelectronics.

Make the top piece the same size as the mattress,round off the corners to avoid banging your shins.

Not sure what optimum size is for backchamber,maybe 1 cu ft or so.Might even work fine without it.

This is the same driver Bill Fitzmaurice recommends for his AutoTuba,or TableTuba,which might be of interest to you,if you wish to make something more conventional.

http://img244.imageshack.us/img244/4861/bedsubyd0.jpg
 
Don that is kinda what I am looking for. Big, cheap and simple. I know that sealing against the carpet is not ideal but I am also kinda using that as a attenuator to keep to much bass from being produced and bothering my neighbors. What I may do is seal the rear chamber of the sub and leave the rest to seal to the floor. Luckily my building has very thick cinder block walls and sound does not transfer and I am on the ground floor.

The MCM sub is the right price but I am curious if you think a tangband sub might be better.
 
Hi.
There were some thread in the german diy.community a while ago.

It´s in german, but the pics probably say it all.

single bedhorn 1x15:
response:
http://home.arcor.de/lionking16/vergleich.jpg
plan:
http://home.arcor.de/lionking16/Betthorn.pdf

double bedhorn 2x12 or 1x15 or 1x18:
response:
http://lionking16.li.funpic.de/doppelbett2kappa12.jpg (2x kappa12)
plans:
http://lionking16.li.funpic.de/doppelbett210x210plan.jpg
http://lionking16.li.funpic.de/finaldoppelbett210x210v2.jpg

Haven´t made one, nor heard it.

Michael
 
My first attempt at building a tapped horn was a miserable failure because I left one side open,and placed it on the carpet.There was no bass.Just placing it on the other piece of MDF made a huge improvement...had to sit on it to keep it from rattling.

I like the statement made by F.Pain in his book The Practical Wood Turner: "Many people have had excellent results doing the opposite of what I say."

Go ahead and try it,if it doesn't work,its a simple matter of adding another sheet of plywood or MDF on the bottom.

I have no experience with the TB drivers,I imagine they would work well. Actually,I have no experience with the MCM driver,either,but it's cheap,and has been used in Bill Fitzmaurice's Tubas,so should be a good candidate. I ordered a pair of them yesterday to play around with.

In the Super Overkill department, a LABhorn under the bed would be cool...www.prosoundweb.com/lsp/

A while back,I built a modified version of the LABhorn,using the same drivers and parameters,but changed the height to 33" to get a larger screen size for my HT.It wound up being 48" long,and to avoid making a 30" wide cabinet,I made it in two pieces,each 15 1/2" wide.(14" internal)

Two of these cabinets,laid on their sides,would be 48"x66"x15 1/2" high,perfect for under a bed.

If anyone is interested,here is a pic and the plans.

http://db.audioasylum.com/cgi/m.mpl?forum=hug&n=107745&highlight=time+alignment&r=&session=

http://img131.imageshack.us/img131/903/scan00055ao.jpg
 
I'm currently in the process of building a pair of Don's tapped horn design* for the LAB12 drivers for my bedroom system. They will (just) fit under the bed lengthwise but are too high so I'll make some small stands for the bed to raise it the 60mm or so it needs. Mouths of the TH's will be at the foot end of the bed, about 600mm in front of the mains, which at this monent in time are Realistic Mach1's (first series) but may soon be changed to Klipschorns.

The TH's are an easy build and will cost about $A30 for the two sheets of MDF. I already own the drivers.

* search fairly early in the big TH thread.
 
This is a diy system inspired by the Avantegarde Trios and Edgarhorn Titans.

Midbass is 110 hz 1/2 space expo horn,basically a round version of the front horn portion of the Altec 828 (A7),with Altec 416-8a drivers.(currently using JBL 2205a).

Midrange is 345 hz Tractrix,with JBL 2441 compression drivers.

Tweeters are Fostex T925a

The tapped horns are on the other side of the wall,one in the garage,the other in a closet,feeding into the room through openings in the wall.

Looking forward to hearing your results on the tapped horns,seems as everyone has written off the LAB12 as not suitable for a tapped horn,but it works for me....
 
Don't know why, here's a conic quick sim in ~375.6 L corner loaded @ ~100 W:

GM
 

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Don Bunce said:
This is a diy system inspired by the Avantegarde Trios and Edgarhorn Titans.

Midbass is 110 hz 1/2 space expo horn,basically a round version of the front horn portion of the Altec 828 (A7),with Altec 416-8a drivers.(currently using JBL 2205a).

Midrange is 345 hz Tractrix,with JBL 2441 compression drivers.

Tweeters are Fostex T925a

The tapped horns are on the other side of the wall,one in the garage,the other in a closet,feeding into the room through openings in the wall.
Very nice Don. Did you turn up the flares yourself?

I still wish I had the space for fullrange horns again Maybe in a few years when I move back to my home and have my huge open plan room back.
Don Bunce said:
Looking forward to hearing your results on the tapped horns,seems as everyone has written off the LAB12 as not suitable for a tapped horn,but it works for me....
My desire to use this driver is quite pragmatic even if it's non-optimum. I have 4 NIB drivers from when I built my LABhorns a few years ago, a nightmare I won't ever revisit upon myself and yours looked good, easy to build and you spoke highly of their performance vis-a-vis you LAB.
GM said:
Don't know why, here's a conic quick sim in ~375.6 L corner loaded @ ~100 W:

GM
Could I please see the parameter entry screen?
 
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