This is measurement with the same level but 50 cm away. The sub was placed in the middle of the room ca 75 cm high from floor. 50 cm distance does not seem to introduce much cancellation if any. I need to make some measurements outside when the weather gets nicer. And this is without side covers, I yet have to add them to see the difference they make.
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I tried playing it a bit louder. It looks like the resonance is very strong, it buzzes reay hard. I EQ'd only by a guess, so it will need a bit more attention. I was actually surprised how much bass this thing can do and how loud it is inside the room. The funny thing is it seems to interact with the room like the other bass units and it can be heard pretty strongly in another room. I think I will need to get nearer to the sub. Now I am at ca 1 m, no rolloff to speak of and when not buzzing, it is pretty nice. I also think the slot should have been wider for these woofers. I am actualy considering building a bass tower with smaller drivers inspired by XRK's latest speaker - to match the width of my "Kallax" Synergy horn and to serve as a stand for it.
I had to make a high Q -12dB notch at 212 Hz. That got rid of the buzz and the bass is pretty good now. Double bass sounds really like the real thing now and there is plenty of bass for rock and electronic music as well. I started to like this style of bass enclosure. Deep and clear, I am pretty impressed.
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Just for fun, I tried to somehow model this slotted enclosure as OD horn in Hornresp (but with sealed back of a large volume). And this is the result:
Quite a good prediction I would say. I wonder why I could not measure much dipole cancellation with this build.
Hornresp record attached.
Quite a good prediction I would say. I wonder why I could not measure much dipole cancellation with this build.
Hornresp record attached.
Hornresp has a Ripole function. Go to
Help > Input Wizard >Half Space > Direct > Open Baffle > Ripole
What did you measure?
I did not know that, I must have missed that function, thanks. I will check it out.
There are two measurements in this thread. One at the slot opening, one at 50 cm distance. And subjectively, there is not much bass loss at listening distance, which puzzles me a bit. I will have to pull it out of storage and test again.
There are two measurements in this thread. One at the slot opening, one at 50 cm distance. And subjectively, there is not much bass loss at listening distance, which puzzles me a bit. I will have to pull it out of storage and test again.
If the front slot is narrow you might get a good output velocity push forward with higher dB out the front; as long as you arent too far back. How far from the SLOB were you?
When you try it again, see if you can set it up in the near field.
It could be just in front of your listening position, eg under a coffee table or on the floor with a throw over it turning it into a coffee table or foot stool. On the floor you should get a half pi dB boost. Plus a near field proximity boost of maybe >3dB and with less room excitation. Possibly one of best bass options designs.
Otherwise, it could be set up behind. Perhaps elevated and very close for a +6dB to +8dB boost. Perhaps on legs and angled so its hidden behind the chair back and the slot is pointed straight at your ears. If you do 30-90Hz hopefully you wont be able to locate the SLOB behind. The HD higher tones that would give spatial locations cues should be low with the SBOB woofers just idling in a very near field set up.
Photos and measurements please?
When testing, I was around 1.5 m away. Today or tomorrow, I will dig it up, add the wiring again and move it to the upper room. There is no way to set them up in nearfield other than making them smaller and left/right of the couch. I will also make a sketch of the room layout for further discussion. The room is kind of small and difficult to set up due to the existing furniture layout, which cannot be changed. So I am willing to accept some compromises there. The second ultimate system with huge MEHs and bass horns will be set up in another room later.
I did a little listening test. It seems to work quite well. Listening distance is around 2 m. I had to equalize the peak and add a HP filter at 40 Hz to prevent overexcursion. The level of bass is not dropping fast in the room, it strangely behaves like a normal box, I do not understand that. The picture of placement is below (the wooden horn is not connected).
So I have some more measurements in the position shown in the picture.
The red trace is 5 cm away from the front port, the green trace is 5 cm away from the left woofer magnet and the other traces at roughly 0 (yellow), 45(brown) and 90(blue) degrees 1 meter away to the room, all 1/3 oct smoothed.
I wonder what am I looking at. The peak would be normally EQd out, so it would not be there. What I see is low efficiency, but quite flat bass down to at least 40 Hz all over the room (with room influence).
The red trace is 5 cm away from the front port, the green trace is 5 cm away from the left woofer magnet and the other traces at roughly 0 (yellow), 45(brown) and 90(blue) degrees 1 meter away to the room, all 1/3 oct smoothed.
I wonder what am I looking at. The peak would be normally EQd out, so it would not be there. What I see is low efficiency, but quite flat bass down to at least 40 Hz all over the room (with room influence).
I am afraid one of the woofers gave up. It produces some buzzing and rattling, the other one is completely free of that. Need to wait for replacement to arrive.
Most probably. Or it could have been bad since beginning, they are quite cheap. I use a high pass to limit the excursion.
Hey what is that a speaker attached to the side of that wood horn or I'm seeing things
Thanks for the reply I thought it was a compact unity horn it would have been cool if it was the world's smallest unity horn
I have just replaced the woofer with a brand new one. And it makes exactly the same noises. While replacing, I noticed that the MDF got ripped a bit while I was tightening the too long screws. So that is most probably the source of the funny noises. When I cover the slot with hands, it becomes more noisy - so I will get rid of the box and build just a sealed one with two opposing woofers - and hope that the noise will go away.
While looking at the excursion, it looked like it never went over 5 mm, while having XDamage of 18 mm, so fingers crossed🙂
While looking at the excursion, it looked like it never went over 5 mm, while having XDamage of 18 mm, so fingers crossed🙂