The dual Ikea Kallax subwoofer

[kemmler3D]

You think the rattle will be so substantial that I would still benefit from it?

I have 3 IKEA Kallax shelves in my house and I would personally be pretty worried about that.

 

[Zek]

@Tell How do you plan to attach the front baffle to that cardboard construction?

 

[kemmler3D]

@Tell How do you plan to attach the front baffle to that cardboard construction?

I think the idea is to build normal subs and then place them inside the shelf... If not I would say this whole thing seems like a bad idea. These shelves are constructed like 2 notches more sturdy than a cereal box.

 

[voodooless]

It does not. See section 5 "Modeling flared ports and prediction of tuning" (page 9-12 of the PDF, numbered as page 30-33) of this paper.
I'd expect the actual tuning to be slightly lower than predicted due to the proximity to the side and bottom panels, but the effect should be small.

It does, and so says the paper:

 

[bmc0]

It does, and so says the paper

No it doesn't. Main determinate ≠ chief determinate. Perhaps you should read more carefully—

 

[voodooless]

No it doesn't. Main determinate ≠ chief determinate. Perhaps you should read more carefully—
View attachment 463304

Well yes, but the difference is so minimal as to not matter, at least in the specific instance the OP has at hand. The margin or error due to the many other factors is probably much larger.

And technically, it does “use” the lowest diameter in the calculation. So my observation was in fact totally correct . However, what I meant to say was that it appears that the tuning is remarkably close to the minimum diameter number, which I would not have expected. Given this, it’s not surprising that multiple people reacted to the port length being too low when glancing at the internals of the box.

 

[voodooless]

How id you battle those resonances btw?

Main audible resonances were from the closeness of the box and enclosure walls. I just shoved some
Stuffing in to couple both. That took care of the worst audible issues. The rest I left as is. Luckily the doors did not rattle

 

[bmc0]

And technically, it does “use” the lowest diameter in the calculation. So my observation was in fact totally correct .

Well, I guess you got me on a technicality.
It's true that the difference is small in this case. Using A_min instead of A_eff would only lower the predicted tuning frequency by about 6%. The main point I was trying to make is that the flare is indeed taken into account.

 

[JohnnyNG]

Well yes, but the difference is so minimal as to not matter, at least in the specific instance the OP has at hand. The margin or error due to the many other factors is probably much larger.

Not the least of which is the fixed room placement of the subs which will affect FR far more than a slight deviation of Fb from plan.

 

[JohnnyNG]

Your solution lacks depth, and since the BR tuning is at 35hz you cannot boost below/at 35hz.

This is key since the driver unloads below tuning.

 

[Tell]

I have 3 IKEA Kallax shelves in my house and I would personally be pretty worried about that.

I'm trusting @voodooless here, his Bestå seems to have the same kind of boards and he didn't have any problems with the vibrations after som felt stuffing. But again, if there will be any major problem I'll just put them outside of the Kallax. But I thank you for your concern and hoping you are wrong for once

@Tell How do you plan to attach the front baffle to that cardboard construction?

That would be a great idea actually, that would actually give me roughly another 10 liters to work with!
.. nope I won't It'll be a box inside the box.

 

[voodooless]

his Bestå seems to have the same kind of boards and he didn't have any problems with the vibrations after som felt stuffing

I didn't say there were zero problems; I just said I fixed the most major issues

 

[Tell]

I didn't say there were zero problems; I just said I fixed the most major issues

Ah well, I've always had vibration problems with random things in my room when I've had big woofers, so hopefully I'll manage ^^

 

[kemmler3D]

I'm trusting @voodooless here, his Bestå seems to have the same kind of boards

Nope! Can unfortunately confirm this is not the case!

I have a Besta unit also, and they are not made from remotely the same kind of boards. The Besta is made from particle board, sort of recognizable as wood, the Kallax is made from some kind of honeycomb cardboard-like stuff with laminate on the outside, which is why it's so thick but can also be easily carried by one person.

I think it's the same material used for Lack tables, which if you've ever tired to sit on one, certainly live up to the name...

It's possible you can sit some subs in there without issues, but do be aware that Kallax shelves are on the bottom tier of IKEA furniture sturdiness. This is why I'd say you 100% can't use the shelf itself for the sub cabinet, it would last for about half an hour at full volume.

 

[voodooless]

I have a Besta unit also, and they are not made from remotely the same kind of boards. The Besta is made from particle board, sort of recognizable as wood, the Kallax is made from some kind of honeycomb cardboard-like stuff with laminate on the outside, which is why it's so thick but can also be easily carried by one person.

I think the Besta is a mix. The top and bottom for sure are made out of the same cardboard like stuff. I know, I cut a giant hole I it

The sidewalls might be different, though.

 

[kemmler3D]

I think the Besta is a mix. The top and bottom for sure are made out of the same cardboard like stuff. I know, I cut a giant hole I it

The sidewalls might be different, though.

It's likely there are variations, the one I have is all particle board. Either way I don't trust the honeycomb cardboard stuff beyond light duty.

 

[Elgrosso]

The besta 60x64x20 and 120x64x40 I tried had top and bottom with a particle board frame around the honeycomb, sides were full particles. But maybe they keep changing this to optimise, or vary per size.
For kallax I’m not sure i didn't cut everywhere, it is flimsier for sure but maybe just because larger.
They might be built like lack, with only 4 cube in corners with particle board, so no frame.

Nope, just found this online:

So 4 cubes for the screws + frame, taller but thinner than on eket (my tests):

But it will work, especially if it’s a build for fun and not ultimate hifi.
In case you’ll glue anything to the internal skin, make sure to sand or scratch the surface. the top layer is very smooth.
Once done it will be ok with just regular wood glue, but cyano even better.

Are you decided on the kallax? Some other models would be stronger, that use full particles and have better volumes to leverage, like skruvby or radmanso.

 

[DanielT]

Now that the kid is finally starting daycare, which means dad is finally getting a bit more free time, and now with some decent finances and a with a new living situation that allows it; it's time to build some bass! But being a bit of a minimalist and with WAF to consider the plan is to squeeze them (yep, I want two) into a Ikea Kallax.

View attachment 463084
The internal dimensions of a Kallax according to my ruler are 34x34x34 cm (with a few mm of variation, probably due to imprecise assembly), which gives 39 liters. But since I want a bit of margin on the sides (where I'm also considering adding some kind of wedge) I lose about 0.5 cm on each side, and with 16 mm thick panels that leaves me with a remaining volume of 25 liters.

I've set my sights on the Dayton Audio DSC255-4, a 10” driver with a Vas of 32.1 liters and an Xmax of 8.3 mm, which costs around 170 EUR from Soundimports.eu. I’m planning to tune the box to 35 Hz using a 3D-printed flared port, based on this guys work. 25 cm long, with an internal diameter of 6.1 cm and an exit flare of 9.2 cm. According to the designer’s excel sheet this gives a max port SPL of 99 dB which I assume means that above that there's a risk of port noise? I’d obviously like something larger, but with a 9.2 cm port on the front, space gets very tight since the driver also needs to fit. A regular straight port of similar size in WinISD shows a velocity around 50 m/s at 200W, which is quite extreme! Though maybe the flared port can handle it better? I have considered placing the port on the back, but I’d prefer (look wise) to keep the Kallax as close to the wall as possible.
The driver, port, and bracing will take up a few extra liters, so the total volume looks like it’ll end up around 23 liters, not a lot but still a fun challenge for a minimalist like me
View attachment 463085
View attachment 463086
WinISD gives me this curve, which I think will perform quite nicely with a bit of EQ, at least compared to what I’ve had since moving to Norway seven years ago.

What do you think? Should the port go on the back after all? Or use two of them? Are there maybe even better drivers for a Kallax (preferably in the same price range)? Or should I drop down to 8” to better accommodate the port?


And this might be something for later on though, but I'm also thinking how to integrate them with my current Ino Audio piP? Those actually play quite well down to 30 Hz despite their small 4" woofer, but of course I want more SPL! And just as important; a smoother bass response in the living room. So I’m thinking of letting the piPs still run full range but at a lower level, and then supplementing them with these Daytons placed between them under the TV to help even out the bass.
Or is it better to just cut the piPs at around 80 Hz and let the subs handle everything below that?

Is it set in stone, decided that you will build with that Kallax? Otherwise, if one of your important criteria to let subwoofers blend in aesthetically in a combined listening/living room, then as a DIY you have a lot of possibilities. Only your imagination sets the limits.

Kallax looks good but there may be problems with vibrations/rattle as others have mentioned.

I'm throwing out some ideas. Two freestanding subwoofer boxes in the same appearance/looks as, for example, two storage boxes. As in the picture in #1 with the subwoofer freestanding, a few centimeters from the storage boxes.
Subwoofers in corners of the room, down fiering. In corners, subwoofers can then be perceived as taking up less space in the room. I can guess that is the case.
Under the sofa subwoofer (a possible disadvantage/challenge; the sofa itself can vibrate then).
Basically anything, furniture-wise, that has a cavity, you can consider making one, or more, subwoofers out of.

Built-in subwoofer drivers in the wall. If possible.

 

[Tell]

The besta 60x64x20 and 120x64x40 I tried had top and bottom with a particle board frame around the honeycomb, sides were full particles. But maybe they keep changing this to optimise, or vary per size.
For kallax I’m not sure i didn't cut everywhere, it is flimsier for sure but maybe just because larger.
They might be built like lack, with only 4 cube in corners with particle board, so no frame.

Nope, just found this online:

So 4 cubes for the screws + frame, taller but thinner than on eket (my tests):

View attachment 463436

But it will work, especially if it’s a build for fun and not ultimate hifi.
In case you’ll glue anything to the internal skin, make sure to sand or scratch the surface. the top layer is very smooth.
Once done it will be ok with just regular wood glue, but cyano even better.

Are you decided on the kallax? Some other models would be stronger, that use full particles and have better volumes to leverage, like skruvby or radmanso.

I have decided on the Kallax since that's what I already have at home Looks like I could make it stronger with some work yes, some of the the longer panels I have are already open on the sides since the original Kallax I have was a 5x2, but I cut it in some places so I could puzzle them however I like, so the 4x1 that I have now do have openings on one end, so I guess I could use something long and sharp to pick out the cardboard stuff and then fill it with something. Might maaybe happen later IF I have to big of a resonance problem. But I'll start with what I have and hope for the best

Is it set in stone, decided that you will build with that Kallax? Otherwise, if one of your important criteria to let subwoofers blend in aesthetically in a combined listening/living room, then as a DIY you have a lot of possibilities. Only your imagination sets the limits.

Kallax looks good but there may be problems with vibrations/rattle as others have mentioned.

I'm throwing out some ideas. Two freestanding subwoofer boxes in the same appearance/looks as, for example, two storage boxes. As in the picture in #1 with the subwoofer freestanding, a few centimeters from the storage boxes.
Subwoofers in corners of the room, down fiering. In corners, subwoofers can then be perceived as taking up less space in the room. I can guess that is the case.
Under the sofa subwoofer (a possible disadvantage/challenge; the sofa itself can vibrate then).
Basically anything, furniture-wise, that has a cavity, you can consider making one, or more, subwoofers out of.

Built-in subwoofer drivers in the wall. If possible.

All good considerations from you! Because yeah I could of course build woofers to have next to the Kallax to "extend" it, which would as it looks now give me around 64 external liters to work with. I'm also aware that corners are better for efficiency and easier to "hide" bigger things. I have even for years been playing with the thought of building a TPAM10HTL, a tapped horn with a 10" woofer that can reach down to 20Hz which would be awesome, I already have built a smaller THAM6 with a 6,5" woofer that plays seriously loud considering it's small size, so a bigger one would be really cool!
But noo, I would prefer to keep the living room as is now, with just some round and sexy woofer looking directly at me while playing my bass music, and I'm sure my girlfriend would appreciate having them incognito as well even though she really do accept my hobby. I do even have some thoughts about floor to ceiling line arrays in the future and I'm sure she won't object

 

[DanielT]

I have even for years been playing with the thought of building a TPAM10HTL, a tapped horn with a 10" woofer that can reach down to 20Hz which would be awesome, I already have built a smaller THAM6 with a 6,5" woofer that plays seriously loud considering it's small size, so a bigger one would be really cool!

Well if you like sawing, gluing and screwing together and can squeeze a couple of big ones into the corners, then why not a couple:

Hifi Vintage DIY fair with pictures

Yesterday was the fair again. Unfortunately I was not able to participate. BUT I am including some pictures taken by a Solhaga. Pictures are always fun.:p Me, or rather via Google Translate the text to the pictures. If you have any questions about the items shown, ask. I have decent knowledge...

audiosciencereview.com

I've heard of them. Sounded damn good. WAF with such a refrigerator big horns in the corners, well then you probably have to be creative regarding painting them, make them blend into the living room.

Hifi Vintage DIY fair with pictures

Yesterday was the fair again. Unfortunately I was not able to participate. BUT I am including some pictures taken by a Solhaga. Pictures are always fun.:p Me, or rather via Google Translate the text to the pictures. If you have any questions about the items shown, ask. I have decent knowledge...

audiosciencereview.com

Detailed construction thread, a lot of pictures and measurements so even those who don't know English (there is automatic google translate) can find that thread below interesting. The first posts in the thread are about his DIY speakers. A bit down on the first page of the thread he brings up his horn, or variant of a tapped horn:

HiFiForum.nu - Forsmans lek- och lärstuga - inte helt hundra. . .

www.hififorum.nu