Not possible before DSL crossovers became available, but....
1. present-day sub-woofer systems have drivers which have their resonance inside the passband which is idiotic,
2. whatever charm some may find in full-range or wide-range drivers, the direction of progress has been with division-of-labour into frequency bands a specialized driver can handle well.
Which leads me to a recent discussion of car audio drivers, which aren't always taken any too seriously by folks seeking sound quality outside of cars.
Perhaps an approach that merits some discussion would be to use one of the car audio monster drivers as a sub-sub-woofer in the band below, say, 35 Hz (chosen for relevance for playing that 32 Hz organ pedal note). There may be no reason to buy the best quality car audio driver, just good enough with low driver resonance.
That means then that the familiar subs discussed on this forum could at last properly handle, say 35 to 110 Hz, and so on up.
When we freed mid-range drivers from having to handle woofer frequencies decades ago, we started using small wonderful ear-height mid-range boxes, with many advantages. Likewise, once we free subs from needing to handle that lowest octave, they can be a lot better and smaller even for sealed cabs.
DSL and amps are cheap but floor space for subs is expensive.
Thoughts anybody?
B.
1. present-day sub-woofer systems have drivers which have their resonance inside the passband which is idiotic,
2. whatever charm some may find in full-range or wide-range drivers, the direction of progress has been with division-of-labour into frequency bands a specialized driver can handle well.
Which leads me to a recent discussion of car audio drivers, which aren't always taken any too seriously by folks seeking sound quality outside of cars.
Perhaps an approach that merits some discussion would be to use one of the car audio monster drivers as a sub-sub-woofer in the band below, say, 35 Hz (chosen for relevance for playing that 32 Hz organ pedal note). There may be no reason to buy the best quality car audio driver, just good enough with low driver resonance.
That means then that the familiar subs discussed on this forum could at last properly handle, say 35 to 110 Hz, and so on up.
When we freed mid-range drivers from having to handle woofer frequencies decades ago, we started using small wonderful ear-height mid-range boxes, with many advantages. Likewise, once we free subs from needing to handle that lowest octave, they can be a lot better and smaller even for sealed cabs.
DSL and amps are cheap but floor space for subs is expensive.
Thoughts anybody?
B.
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What would be the point?
If your woofer goes flat to 35Hz it will only be down 2-3dB at 32Hz which is not audibly discernable.
If your woofer goes flat to 35Hz it will only be down 2-3dB at 32Hz which is not audibly discernable.
I have some organ recordings that go down to 16Hz. But I'm not really bothered about recreating that at home.
What intrigues me is that the bass output required to watch movies in 2.1 or higher format is considerably higher than most music requirements to give you that authentic dino stomp. Does make me wonder if seperate music subs and Fx subs would be a good thing. I don't have space but it;s an interesting discussion.
What intrigues me is that the bass output required to watch movies in 2.1 or higher format is considerably higher than most music requirements to give you that authentic dino stomp. Does make me wonder if seperate music subs and Fx subs would be a good thing. I don't have space but it;s an interesting discussion.
Your sub-subwoofer idea is really just a subwoofer with a relatively low LP filter. It might help to keep HD distortion and modulation issues out of the lower bass. But I suspect that should be able operate it up to at least 50Hz, and have a conventional "woofer" take over from there. That not even a 2-octave bandwidth...
I have turned to car audio vendors to look for what used to be called "free air" or "infinite baffle" drivers with low Fs and relatively high Qts. But in the past these used to be available for home use from DIY cable or Parts Express but are no longer offered. For example:
IB3 Series - IB318 v2 | Fi Car Audio
This driver would work in your application if used in a VERY large box or an in-wall type of IB application.
Depends on the sub-sub 😀
If starting at 50hz and it's supposed to work down to 6hz we get a respectable range, 4 octaves is not too bad?
1 - 50hz
2 - 25hz
3 - 12.5hz
4 - 6.25hz
Guess it falls into the "doable but what's the point" category, IMO useable response to 25-30hz is enough, the rest makes the house shake too hard.
You've gotta work harder on your math skills... what you have showed (6.25 Hz to 50 Hz) is 3 octaves, not four. 🙂
Anyway, who said anything about 6 Hz? I believe someone mentioned the 16Hz organ pipe, so I thought 12 Hz (thus 2 octaves) would be plenty of LF extension... not to mention that sound waves are not likely audible or even "feel-able" below that unless there is enough SPL to crack your house in half.
Sub-10Hz stuff is the realm of home-theatre, er, enthusiasts - not IMO useful for music reproduction.
I've RTA'd a kick drum with 16Hz a mere 3dB down on the 32Hz component, but it did sound distinctly "flubby" acoustically - the plastic bass tube mounted to the resonant skin had pulled the harmonic series way down in frequency.
Chris
I've RTA'd a kick drum with 16Hz a mere 3dB down on the 32Hz component, but it did sound distinctly "flubby" acoustically - the plastic bass tube mounted to the resonant skin had pulled the harmonic series way down in frequency.
Chris
I've done this with 3 x Adire audio tempests each in their own sealed 220L cab below a pair of labhorns, crossed at 30Hz. (the room was 20' x 10')
It worked really well keeping the 'tightness/speed' of the horns plus the pressurisation of the room in the very low frequencies.
The tempests sounded 'slow',' bloated' etc (hifi terms.. sorry!) when used up to 80Hz in the same setup.
Crossover was the Behringer DCX.
Rob.
It worked really well keeping the 'tightness/speed' of the horns plus the pressurisation of the room in the very low frequencies.
The tempests sounded 'slow',' bloated' etc (hifi terms.. sorry!) when used up to 80Hz in the same setup.
Crossover was the Behringer DCX.
Rob.
Ooops, I forgot to mention freedom from Doppler distortion - but that's done by keeping long-travel low-bass in the sub-sub and out of the sub and mid-range.
But in our audio world, there's rarely a measurement of intermodulation issues and that's part of what makes big panel low-movement speakers (ESLs, etc) sound so dramatically cleaner.
Always a question about the practical logic of crossover points. I start by assuming subs are mixed-bass. So whether one or two bands, can't crossover north of 140 Hz on music. So feasible to get a sub-sub to do one or two 8aves south of 35 and a sub to do one or two 8aves north of 35 Hz.
B.
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Hmm, me and some others have been advocating mobile audio 'sub' drivers for HIFI/HT apps for at least 20 yrs now, mostly for < 80 Hz.
For HT, Dolby set the 80, 120 Hz 'LFE' XO points [THX reference] much earlier. Personally, used 120 Hz from a '70 Popular Electronics article on how to build a 'super' woofer's solid state adjustable volume XO, which worked well once the corner loaded ~14 Hz tuned subs were 'blended' in with my then 20 Hz Fs tuned, 500 Hz XO woofers.
That said, in '68 Altec gave me a less enhanced version of this instrument chart to help with driver/horn/whatever selection that I've otherwise followed/recommended, though folks typically stick with 80 Hz for subs: http://www.audio-issues.com/wp-content/uploads/2011/07/main_chart-610x677.jpg
IME, the main thing is to limit its BW to the driver's upper [Fhm]/lower [Flc] mass corners where T/S theory apparently falls apart, though normally the latter is only useful if designing a BagEnd style sub where only the BW below Fs is used:
Fhm = 2*Fs/Qts'
Flc = Fs*Qts'/2
Qts' = 2*Fs/Fhm
Qts' = Qts + any added series resistance [Rs]: HiFi Loudspeaker Design
In short ~15-60 Hz [2 octaves] sub, 60-250 Hz [~2.06 octaves] bass, though from here I prefer the mids be the telephone's 250-2500 Hz decade [~2.67 octaves] and personal preference for upper mids, HF.
You're right, limited to ~2 octaves, we don't need 'HIFI' [wide range] drivers now that DSP is so comprehensive, relatively cheap; for instance a 20 Hz Fs driver for a 60 Hz XO [120 Hz HF] ideally needs a decent ~0.33 Qts sub with plenty of power handling and a modest ~0.48 Qts for the ~30-500 Hz prosound woofer before factoring in wiring losses, usually only ~1/2 ohm.
GM
Hahah! Well, that's not really a mathematical error on my part, more like a complete breakdown in logical deduction skills 😀
Not arguing, don't see the point myself. Except if you want to see your doors or pants flapping about.
It doesn't have to be that "loud" to have an effect, I find very low bass can give a sense of the recording space on some live recordings.
i used phoenix cyclone for many years as subsonic woofers in my hometheater. 10 to 45hz.
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Very much so, especially some recordings of big church organs. Can feel the air moving around in the big space, close your eyes and it really does feel like you're in that particular church by yourself. Only thing that sort of ruins it is that the chair is more comfortable...
I could not learn anything at the Phoenix Cyclone website. Is there an explanation or diagram of the device somewhere?
BTW, of we are thinking about a sub-sub 4-way speaker system, there are a few more options for sub-sub drivers. There's a driver based on a servo motor (with a belt drive, if I recall). You can also add weight to a conventional cone woofer to get the resonance lower. And you can use a vibrator gizmo on your chair or wall.
I sometimes "hear" great organ music just walking down the street. But aficionados of organ music and reproducing it at home sure know and can feel in their bones the presence of low bass. Conversely, we hear perfectly clearly that just having 12 Hz speakers does not reproduce the sound (let alone the acoustic ambience) of being in a big church organ pew.
Although at present my two very large subs (sealed and 17-foot labyrinth) can pump out the pedal notes, for 60 years before I was alright with my brain inserting the fundamental notes.
B.
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The Cyclone was designed by Tom Danley I believe
Eminent Technology: home has some good stuff on the concept and Spectacular Alligator Mating Display | Animal Super Senses | BBC Earth - YouTube shows a video of a couple of them being used to troll an alligator into making a mating display.
Eminent Technology: home has some good stuff on the concept and Spectacular Alligator Mating Display | Animal Super Senses | BBC Earth - YouTube shows a video of a couple of them being used to troll an alligator into making a mating display.
Yes, Danley.
The Phoenix Cyclone is powered by a servo-motor. A 2003 explanation (??), long discussion, and faulty links at:
PG Cyclone and Other Servos | Car Audio at CarAudio.com
B.
The Phoenix Cyclone is powered by a servo-motor. A 2003 explanation (??), long discussion, and faulty links at:
PG Cyclone and Other Servos | Car Audio at CarAudio.com
B.
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Hi There,
Your thinking is very much along the lines of my 5-way PA system, which uses 6x 18" sealed from 60Hz - 120Hz (6kW) and a pair of ported 21" (5kW) from 60Hz down to about 25Hz cutoff. (Mid/HF per side is a pair of horn-loaded 12" plus a BMS coaxial compression driver).
This has grown from my original 'pub' system using 2 x sealed 18", which, surprisingly, required LF filtering to reduce audible - and very visible! - turntable rumble, which I had expected to be significantly outside their range. If I was trying to achieve your goals I would not hesitate using as much cone area as I could possibly afford in sealed enclosures. The amount of energy stored in any resonant or labyrinthine (horn) enclosure with a response approaching single-digits would make it unlistenable in my view. Look up Double Bass Array and Single Bass Array plus SUB Wiener Neustadt for a little-used, but in my opinion excellent method of reproducing clean low bass.
Sealed subs also possess the advantage of being able to pressurise a reasonably well-sealed room so you can win some extension there too. My mantra for bass is "MOVE A LOT OF AIR - gently..." and be ready to buy some big amps too. I have never heard a 'fan' type sub but could imagine that they might be limited to LFE and not music.
Good luck, Carl.
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