(yep, my bad, the four 1.6 looked like 1.7 in the dark !)
Thanks for the system description... what a big work 🙂
The +10 dB 20hz to 150 hz is impressive. Seems room gain doesn't help that much and one needs lot of boost EQ. That is also a lot of emissive surface with all that planars.
Did you feel a compression chest feeling with the DBA ? Is this pressure could move the thin planars diagphragmes ?
Thanks for the system description... what a big work 🙂
The +10 dB 20hz to 150 hz is impressive. Seems room gain doesn't help that much and one needs lot of boost EQ. That is also a lot of emissive surface with all that planars.
Did you feel a compression chest feeling with the DBA ? Is this pressure could move the thin planars diagphragmes ?
Beautyful curve for us bass-lower´s Stig 👍 , may i ask you what SPL it can play ( with a little headroom) ?
Regards John/Sweden
With roughly the same room cross section, I have ~2500 nominal volume displacement available and Stig's is 6500. For a rough estimate, you can add 9dB to my graphs))
With 20 dB headroom?))
https://www.diyaudio.com/community/threads/my-double-bass-array-with-low-q-subs.392998/post-7195562 +9 dB
Hahaha... 😉 ...Sounds real good to me!....My 6 X 12 inch Peerless xxls 100 liter/reflex/ tuned to 22 hz is about the same, but not all way down to 17 hz...
Newer 🙂 I will newer take a real good tuned reflex and make it a limited "worse" sealed with less SPL
Have you heard a real real good reflex, where a Ocilattionmeter have show you the result in the port before you listen to it ?
And in DBA case, rear half of the subs are inaudible 🙄.. However you can try DBA or source-to-sink with you subs, if room is suitable
Would have loved a DBA solution in my room, but don´t have cash enough to make it.
So i keep "fighting" with "smaller things", and keep on trying to do the best of it
The most important feature of a well-tuned DBA is not necessary the frequency response, but the decay. You can almost say that a DBA will make your room anechoic, or very close to. My setup is pretty good down to 25 Hz or so, as this REW wavelet shows. There is no bass absorption in my room at all!
My max SPL is limited by availiable amp power, which is approximately 2x500W in 8 ohms for both arrays. The amps start clipping around 110 dB.
I measured the distortion at three levels as shown below. With more amp power, I could achieve even higher max SPL with not all that much distortion.
Red line is 2nd harmonic, yellow is 3rd.
I measured the distortion at three levels as shown below. With more amp power, I could achieve even higher max SPL with not all that much distortion.
Red line is 2nd harmonic, yellow is 3rd.
Well, when there is a dedicated room for audio in your house, you can build DBA, bass-traps or whatever you want 🙂
I have a rented apartment and have to be modest in my desires. But in general, the result suits me:
I have a rented apartment and have to be modest in my desires. But in general, the result suits me:
It's a bit odd and took a lot of experimentation to get it to work.
Firstly, I have a living room connected to the kitchen and corridor, which gives strange and unpredictable bass behavior with anomalies around 40 and 80 Hz. On the positive side, I have a large window area, I think this reduces the overall reverb on the bass (though it didn't help on its own).
I have 2 dipole speakers that can play from 35-40 Hz in this room + two servo subwoofers, but they are located in one place in the room.
Subwoofers play with dipoles up to 100Hz. There was one single place in the room in which there was a fairly even response up to 100 Hz. In all other positions, and I try all of them, in stereo and mono subs 🙂 there were deep peaks and dips. The subwoofer crossover was chosen empirically to remove the dip in the 80Hz region that the dipoles had. The main speakers were delayed by 20ms to keep the subwoofers in timing.
I add a 35 Hz crossover for the main speakers, which reduces anomalies in the 40 Hz region. I accidentally discovered that adding a crossover there affects the room modes, and searched for its slope to improve the picture on the spectrogram.
And of course, some EQ for subs, dipoles and all together. The result is a distributed monopole + dipole 2+1 system, crucial to getting a smooth response was to find the optimal place for the subwoofer, adjust the delay and look for high / low crossovers for subs and dipoles, which, by their interaction, reduced room effects.
That's how it looks. Subwoofers in the upper left corner under the ceiling on the wardrobe.
DIY, Faitals 18'' + RCF 940 in 950 horn, passive crossover + EQ, quite happy with them 🙂
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