The dual Ikea Kallax subwoofer

[DanielT]

I do even have some thoughts about floor to ceiling line arrays in the future and I'm sure she won't object

I thought these mini line arrays were nice. Modern in design, probably acceptable WAF (the big sub is probably not). Okay they don't go from floor to ceiling (which is an advantage considering the reflexes if they do) but other than that they look good:

Line arrays with:

https://en.toutlehautparleur.com/fullrange-speaker-lavoce-fsn020-71f-8-ohm-2-inch.html

Little Big Line Array Build

After building quite a few subwoofers and 2-way speakers over the years, I was looking for something different, and line arrays fit the bill nicely. Line arrays have some intriguing characteristics such as little loss of volume as you get further away, low distortion, and very slim enclosures...

audiosciencereview.com

These have been, probably still are, popular to build line arrays with:

Peerless TC9FD18-08 | HiFiCompass

The THD measurements at voltage level 2.83 Volt were carried out with High Pass Filter "on" (2nd order Butterworth type, 80 Hz cutoff, HPF2-80) The THD measurements at voltage level 4 - 11.2 Volt were carried out with High Pass Filter "on" (2nd order Butterworth type, 150 Hz cutoff, HPF2-150)...

hificompass.com

 

[Tell]

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:
View attachment 463575View attachment 463576

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

I guess I could get away with a pair of really tall and thin tapped horns in the corners But no that's for another time Still interesting thread, and my svenska är mer än tillräckligt god för att förstå utan någon google translate ^^

I thought these mini line arrays were nice. Modern in design, probably acceptable WAF (the big sub is probably not). Okay they don't go from floor to ceiling (which is an advantage considering the reflexes if they do) but other than that they look good:
View attachment 463578
Line arrays with:

https://en.toutlehautparleur.com/fullrange-speaker-lavoce-fsn020-71f-8-ohm-2-inch.html

Little Big Line Array Build

After building quite a few subwoofers and 2-way speakers over the years, I was looking for something different, and line arrays fit the bill nicely. Line arrays have some intriguing characteristics such as little loss of volume as you get further away, low distortion, and very slim enclosures...

audiosciencereview.com

These have been, probably still are, popular to build line arrays with:

Peerless TC9FD18-08 | HiFiCompass

The THD measurements at voltage level 2.83 Volt were carried out with High Pass Filter "on" (2nd order Butterworth type, 80 Hz cutoff, HPF2-80) The THD measurements at voltage level 4 - 11.2 Volt were carried out with High Pass Filter "on" (2nd order Butterworth type, 150 Hz cutoff, HPF2-150)...

hificompass.com

Cute lines! But a bit to short for my taste When it's time for me to build a pair there's a big chance I'll go for the TC9, I've seen many successful builds with them!

 

[Tell]

So after fiddling with the port I realised that I can't physically fit what I need when having a 10", so I've scaled it down to 8" instead! The contenders now are SB Acoustics SB23MFCL45-4 as suggested early on in the thread, and also the GRS 8SW-4HE-8. Feeding both of them into WinISD with the same box and tuning they are really quite close, even at max SPL, with the biggest difference being in the upper range where the difference is around 2dB, which is not that big but on the other hand not insignificant either where I would need almost another of the GRS to come out on par with the SB.

But on the other hand, the GRS is half the price for almost the same performance. Thing is though that I don't fully trust the specs of the cheaper "Generic Replacement Speaker", there are a Reddit post where the bigger ones have been measured and is not according to spec. So the 2dB difference might actually be bigger than what WinISD is saying.
But then it's also about the looks, which to me actually is quite important! I really do think the GRS looks quite a lot better. Sure the SB is a bit bigger, but that tiny dust cap in the middle just looks lame while the more flush and bigger one on GSR looks much cleaner and better imo.
First one is SB and the second is GSR:

So all in all, I can't make up my mind! The GRS might be almost as good, half the price, looks better and IF I'll have serious resonances from the Kallax it will be less money down the drain. For the price difference I can even get my self a Raspi5 and Hifiberry DAC8x and build that DSP I've been wanting for a while now!
But on the other hand, the SB Acoustics ain't that bad looking with it's fatter surround and will give me moaar SPL in the upper bas, and potentially even more than what WinISD says. And I'm guessing the distortion is lower as well, but hard to know without any measurements.

So can anyone help nudge me in the right direction?

 

[Flaesh]

can anyone help nudge me in the right direction?

Think less about anechoic response and more about [your] room transfer function?

 

[Tell]

Think less about anechoic response and more about [your] room transfer function?

Sure, but I need to start somewhere right?

 

[jaakkopetteri]

GRS subs tend to measure rather poorly, here's one example https://www.diyaudio.com/community/...fers-distortion-and-15-dollars.360855/page-10

 

[Mojo Warrior]

Silly question, but what are the main speakers that will play with the subwoofer ? And would it be more cost effective to purchase a well designed sub-satellite speaker system ?

Just asking

 

[Tell]

GRS subs tend to measure rather poorly, here's one example https://www.diyaudio.com/community/...fers-distortion-and-15-dollars.360855/page-10

Thanks for the link! Got some useful info about the SB as well. Also seeing that the specs of the GRS seem to be a bit flaky it might not be too good of a pick. So I actually ordered the SB Acoustics SB23MFCL45, looking forward to start building them in a few weeks!

Silly question, but what are the main speakers that will play with the subwoofer ? And would it be more cost effective to purchase a well designed sub-satellite speaker system ?

Just asking

Ino Audio piP. If you're a Swedish audiophile you most probably know what they are and how very good they are considering the size and price. They are a bit obscure though and not too well know outside of the Swedish audio community. The Guru Audio Junior is a near sibling though. I want to build something to replace them one day, but for now they will do more than fine

 

[7Tiger]

I actually ordered the SB Acoustics SB23MFCL45

Make sure you measure their Thiele-Small parameters when you get them - bigger SB drivers may have quite significant deviations from the datasheet, particularly Vas and Qts

 

[Tell]

Make sure you measure their Thiele-Small parameters when you get them - bigger SB drivers may have quite significant deviations from the datasheet, particularly Vas and Qts

Oh, and that was one of the reasons why I didn't go with the cheaper GRS, I thought I could trust SB! Ah well, I don't anything to measure with anyways so I'll just hope it works as specced.

 

[ErVikingo]

Isn't the Kallax hollow wood with cardboard inner? I'm sure it's not solid wood, so you'd need to line it with something substantial like 18mm MDF, which would lose even more volume.

Yes I cut one and it is hollow with cardboard inside.

 

[7Tiger]

I don't anything to measure with anyways

Get yourself a DATS v3 - https://www.soundimports.eu/en/dayton-audio-dats-v3.html
Not very cheap, but useful if you are into DIY speakers
Alternatively, REW can be used to measure T-S parameters, but you'll need to make a jig/cable and, preferably, use an external audio interface (not obligatory, but gives more accurate data than using computer's built-in audio codec)

 

[Flaesh]

Sure, but I need to start somewhere right?

Sure!
Take any closed box with a speaker. You can take one, if you plan on having one subwoofer. Measure its "anechoic" low frequency response (just about a centimeter from).
Now you can place this loudspeaker and the measuring microphone in the desired places. The difference between this measurement and the anechoic frequency response is room transfer function. For these points.

 

[mordikai]

I have 2 subs in my kallax shelving and it works great. Don't cut in to the shelving unit, brace well, dual opposed is helpful for vibration.

 

[Tell]

I have 2 subs in my kallax shelving and it works great. Don't cut in to the shelving unit, brace well, dual opposed is helpful for vibration.

Good to hear! Hoping mine will run just as good!
Got a picture of yours?

Anyways, I have the woofers, a port is printed, the wood has been cut and one box is screwed and glued together. No picture of that, but I got some brutalistic dry fitting from earlier today at least.

 

[Tell]

One of them are finished! Ah well no really, it still needs much better finish, a better looking baffle, the port still needs some work to be smoooth and the shelf needs to be pushed out a bit for the box to go further inside. But it definitely makes some noise, and quite clean noise as well! Really impressed with what this "small" 8 incher can push.
For those worried about resonances in the Kallax I can say that I can't hear any whatsoever (though there are definitely other parts of the house that moves). Looking at some quick and dirty measurements at around half a meter away I get a THD at around 3% at 30Hz with no ugly peaks. Placed outside the Kallax it measures more or less the same.

What the measurements also seem to show is that the port tuning seem to be around 37Hz, which is around 7Hz shy of the 30Hz that I aimed for. Oops! Ah well, I can live with that
I was worried about port noise though, and I can hear some at louder volumes playing test tones, but with music it's nothing that really bothers me. The port do need some work though since I have some seams because I had to print it in three parts, so fixing that might help a bit with the noise.
But I did just finish printing a flat version of that port, ie a closed version. I'm curious to see what these can do sealed and equalized. I mean seeing the xmax working on these looks quite impressive so I want to see/hear how low these can go ^^
And also, I got one more to build!

 

[DVinylfan]

This is great! You had fun, made something cool that works, probably learned a lot, didn't have to sell your house, and maybe inspired others to attempt similar things. Vis-a-vis resonances etc., ultimate performance is less important in a project like this, I think.
All you need to do now is find somewhere to put your records

 

[Tell]

This is great! You had fun, made something cool that works, probably learned a lot, didn't have to sell your house, and maybe inspired others to attempt similar things. Vis-a-vis resonances etc., ultimate performance is less important in a project like this, I think.
All you need to do now is find somewhere to put your records

Thanks! Yeah it's fun building stuff, have been way too long so I'm really glad I'm doing this! Of course it's still work left, got to make this one looks nice and then build the second one. And with just this one and not properly EQd yet I good really nice sounding bass, so with the second one it's going to be awesome! Also trying them sealed will be interesting.

And when I'm done with these I want to have a go at MEH, they really are an interesting concept ^^