As a general rule-of-thumb you want the (sub) woofer system to be at least as efficient as the mains and up to +6 dB depending on room loading conditions, i.e. speaker positions in-room and and the room's gain curve which at best doesn't become an issue until below its 1st eigenmode (~344 m/s/2/its longest dimension), so for a 5 m long room it can theoretically rise at up to 12 dB/octave beginning around 34.4 Hz.
In such a room then, a T/S maximally flat sealed alignment with a 18.2 Hz Fb will in theory sum flat in-room to as low as you want to go. The reality though is that most rooms are lossy down low and have as little as 3-4 dB gain early on, rolling off down low due to the room's structure having too high an Fs.
Without measuring your room then, best to over design WRT efficiency and use EQ to dial it down as required if need be since either boosting it and/or shelving down the mains increases distortion/lowers its dynamic headroom.
GM
Uhhm. Not sure if i understood that... But i am planning to make a quite huge absorbing "plate" on the wall behind the speakers. Mabybe 1½m tall och 2m wide and 5-8cm deep stuffed with something.
Do you think it's a good idea to build a pair of boxes for my RSW-1060 and then when i get more money it's just to swap drivers?
Your 'plate' absorber, or membrane absorber, has a small Q probably somewhere in the mid frequency range . So if you want to absorb low frequencies you have to caculate it's centre Q point that responds to your room resonance. Probably you need a cavity around 30cm and a low mass membrane like triplex to make it work in the >100Hz area.
Yes you are right. I come to an effective Vb 120 - 130 liter, in Basta simulation and i have tried it in practice, but it didn´t sound good.
I even built 80 liter, it was ok and 40 liter even better.
I doubt the parameters are accurately correct at the PDF.
Have not the knowledge to make a complete TS-checking.
I asked in another thread about SDX10 and a guy there said 50l tuned to 25hz.
And that would fit the RSW-1060 aswell. But i'm not sure if the mounting hole is the same. That could cause some problems...
And that would fit the RSW-1060 aswell. But i'm not sure if the mounting hole is the same. That could cause some problems...
Since the subs will play quite far up in frequency... Wouldn't it be good to place them as close to my EL70's as possible? And not like 50-60cm apart but sort of make a stand for the sub and then place the Mar-Kel70 ontop so the drivers get closer to eachother. Good idea? They will play above 80hz and then u can hear where the sound is from, would be fun to have it go up and down like crazy.
In theory you want the driver's acoustic centers to be < 1/4 WL apart at the XO point, so at 80 Hz: ~13560" (34442.4 cm)/4/80 = 42.375" (107.63 cm) and why you see some systems with the woofer down near/at the floor with the mid-bass, etc. up around ear height.
GM
GM
Yes, i want it that way. But isn't it quite difficult to make a 50l box to be around 70cm tall (without any "legs" or such)?
And if not i thought of DIYing some sort of stand for the sub and then place the mains on top of the sub or a stand on the sub for the mains.
The best would be a somewhat tall box that can act as a stand. Maybe a useless chamber at the bottom of the sub which is damped with dry sand or something?
I think 120hz would be quite good actually. But i'm not sure about which sounds are at what frequency though...
And that picture isn't saying me nothing, but it seems like it can be useful.
IME: XO at 80 Hz to the main speakers: At least a 12 dB HP filter is required...at 120 Hz: minimum a 18 dB/octave filter is needed to prevent localization cues drawing attention to the sub bass speaker, i.e. 250 Hz should be at least ~20 dB down.
Adding a simple box layout, See the submitted picture:b 🙂
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Thanks bjorno.
Since i will probably use a Reckhorn S-1 for crossover i can play around a little with that and see what suits me best.
That box, isn't that a TL? Or is it a vented 50l tuned to 25hz?
Since i will probably use a Reckhorn S-1 for crossover i can play around a little with that and see what suits me best.
That box, isn't that a TL? Or is it a vented 50l tuned to 25hz?
Why can't i edit my earlier post?
Well, seems like i can get the SDX10 earlier than i've been planning actually.
Just found out that i won a Fractal Design Define R3 compute chassie which means i can sell my current one for the cost of a half SDX10. And selling my other speakers bring be almost 1½ SDX10. And finishing the work in the woods give me even more. I'm rich! 😀
My current plans are:
50l 25hz box for RSW-1060
Power them with my HK amplifier
Get another amplifier for my mains, with low power but good sound quality (tube amp?)
Get a Reckhorn S-1 which deals with all the filtering to both the subs and mains.
Buy a pair of CSS SDX10 and then sell my RSW-1060 or keep them for caraudio.
I wonder though... I might need a replacable baffle since i guess the mounting hole wont be the same for SDX10 and RSW-1060. But that shouldn't be that difficult to fix, right?
Well, seems like i can get the SDX10 earlier than i've been planning actually.
Just found out that i won a Fractal Design Define R3 compute chassie which means i can sell my current one for the cost of a half SDX10. And selling my other speakers bring be almost 1½ SDX10. And finishing the work in the woods give me even more. I'm rich! 😀
My current plans are:
50l 25hz box for RSW-1060
Power them with my HK amplifier
Get another amplifier for my mains, with low power but good sound quality (tube amp?)
Get a Reckhorn S-1 which deals with all the filtering to both the subs and mains.
Buy a pair of CSS SDX10 and then sell my RSW-1060 or keep them for caraudio.
I wonder though... I might need a replacable baffle since i guess the mounting hole wont be the same for SDX10 and RSW-1060. But that shouldn't be that difficult to fix, right?
Nice work Bjorno, thank you.
Rullknufs you lucky man.🙂
I´ve done some microphone messuring with Room EQ Wizard, in my listening room.
Just two subbs in frontposition, did well.
From 150Hz it show a stright tilted line that ends 8dB up at 20Hz, then it drops rapidly. This roomgain naturally wary depending of room.
Except a roomnode responsible dip at 40Hz, it looks good and sounds ok to. Experimenting with filling at the movement, to make the bass sound as tight as possible.
Rullknufs you lucky man.🙂
I´ve done some microphone messuring with Room EQ Wizard, in my listening room.
Just two subbs in frontposition, did well.
From 150Hz it show a stright tilted line that ends 8dB up at 20Hz, then it drops rapidly. This roomgain naturally wary depending of room.
Except a roomnode responsible dip at 40Hz, it looks good and sounds ok to. Experimenting with filling at the movement, to make the bass sound as tight as possible.
I disagree, but it might be if he meant the raw driver just connected i free air or in a rookie box with improper cabinet load.
Here is the estimated impedance load curve for the CSS SDX10 box suggestion I made earlier without adding any connecting cable resistance or other losses thats always present in the real world.
b🙂
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