As I have shared in other posts...Im looking to use this shape as an enclosure and it coincided with a voight pipe
however many peeps intimated under powering using it as a single driver solution so Im running this question here...what are the thoughts about creating an opposed piston manifold and putting in the base of the enclosure with a down firing port? (Just prelim)
If anyone is interested in helping with this project, I would be happy to pay the time with a set of these sent over to you/you pay freight 🙂
Trying to make something special but my skill is in making them...not the intricacies of component choice/config etc...just a thought
Thanks
however many peeps intimated under powering using it as a single driver solution so Im running this question here...what are the thoughts about creating an opposed piston manifold and putting in the base of the enclosure with a down firing port? (Just prelim)
If anyone is interested in helping with this project, I would be happy to pay the time with a set of these sent over to you/you pay freight 🙂
Trying to make something special but my skill is in making them...not the intricacies of component choice/config etc...just a thought
Thanks
Nothing wrong with the concept.
The driver's exposed rear vents and suspension should be quiet at high excursions, some are not.
Your cross sectional view shows a driver incapable of more than a few mm excursion without the coil hitting the back plate..
Your pictures do not illustrate a Voigt pipe (expanding taper transmission line) or a bass reflex enclosure, which requires a large enclosed volume compared to the port dimensions to function.
What frequency range and SPL are you looking for the subwoofer to achieve?
What are the limits to the volume of the enclosure?
What do you consider to be "special"?
Art
Thanks @weltersys ...the model is just a simple proxy, enclosure design is in anticipation of a tang band W6-1721 although for space I may have to go for a w5 and Im quite happy with both of those both xmax and general value
Sorry I should graphically mud map the concept to help explain a bit more
Bit of a background that might help with perspective:
Im a professional musician of 40 years and mixer of 30, have done a lot of FOH as well: generally we split the subs out to an active fader. When I set initial levels, I turn off the subs, set the midrange picture and slide the subs up as I consider that the fundamentals below 100 and the harmonics above 10k are only supportive; which I mirror when mixing in the studio but I use a Brauer type sub grouping and the sub 100hz are treated without analog intervention and even on the output down mix, they are very much kept to their natural transients (lightly managed) because the kinetic energy down there just doesnt translate well when mashed or crowded (just use a scope and RTA...its a visibly busy space). Incredibly obvious when doing FOH and its 1000s of watts of sub. (its mostly recorded through tube front end though)
(1) Nature of bass
Which brings up the idea of (music) component split subs (ie non transient going to a more natural non transient device and the sheer transient going to a more suitable device hence above concept)
I also mention that because I listen to a diverse array; from recordings we have done of a quartet/Vivaldi through to classic rock, EDM etc...you get the picture..
(2) Calibrated levels
I generally use calibrated levels when mixing; major mix time is 67db A slow, on extremely sensitive midrange forward mix speakers and I dont use sub but rather a tactile transducer bolted to my chair (ie speakers are (100-10k being 1k centric and /10, *10). This also has the calibrated FM loudness curve applied.
My hi res levels are approx 77db on focals.
Final check on ATCs are loud @ 90 (EDM is done on a live system)
So with that context, saying "84db SPL" levels for bass might be indicative of test signal measurement but I never see mention of the context of weight etc so lets assume its an absolute, its the "nature" of the bass @100Hz signal for this device is for the fastest time domain fidelity. In other words, 84db might be the average test signal but with the above background, its the wave crest ratio of the music that requires peaks that are obviously far above that to account for the mix style and mastering. Of course this doesnt even touch on target room size etc
This results listening in calibrated to 84db (pink noise A, slow) but this is based on music with a wave crest ratio that is most closely aligned with a min of K-14/lufs head room. The momentary Lufs will be far louder on -14 db master of course
Most (re)masters these days are more like -10lufs at best so the increase above 74db just gets plain fatiguing and quickly
So all of the explanation is to say that all those variables are really significant which might not be the norm
None within reason as if its somehow possible to integrated the manifold into the (VP) enclosure, great else it will go in the ceiling as an IB and use the ceiling plane as a boundary. I have this in the studio with an inverted down fire and when centralised, provides the most equally dispersed pressure wave and is quite punchy (and had to manage the group/distance delay)
(3) Summary
While this is a general question...its also related to the above where I would like to try remastering existing and new tracks to have the sub elements spectrally unmixed and be routed to 2 different sub bass devices but this is secondary...just something that Ive been wanting to do because it would be trivial to do for my mixes and prob set up an ambisonic output, hacking 2 of the outputs for separated subs...just a thought. Like a .2 system but the subs are coincident with spectrally separated tasks of attack/sustain I guess
Definitely the artistic expression coupled with audio reproduction function. We have been using boxes for a long time. Olson's spherical work is substantial and hence my business name is "Aurasphere" because of this personal rediscovery and the fact that audio is essentially complete founded on the extrapolation of a sphere to time ie sine 🙂
Thanks again for your response!
Since you plan to use the subs for mixing at frequencies below 100Hz, and you seem to value transient response, I'd suggest using sealed enclosures rather than Helmholtz resonant based enclosures like bass reflex or transmission line/Voigt pipe variants.
Since your SPL requirements seem modest, the 6" mid bass Tang Band W6-1721 may be adequate, four could reach 92dB peaks at 20Hz at one meter with no room gain without exceeding Xmax.
I'd consider flat to 20Hz a minimum for a serious control room application this century.
If you want +14dB peak headroom over 84dBA (slow) down to 20Hz, eight W6-1721 would be required.
You would need around sixteen W6-1721 if you wanted them to keep up with a 90dBA (slow) mix level.
Probably better to use fewer larger drivers if you want to hit full scale low frequency peaks without too much distortion- Xmax is ~10% THD.
If you are interested in accurate reproductions of other's mixes, I'd suggest stereo subs.
Reverse mounting the drivers would reduce their voice coil heating (which causes the voice coils to heat up and impedance to rise "thermal compression"), but if you allow ~30 liters per driver, heat should not be a concern with music with "normal" (as we grew up with) dynamic range. The suspension and vent noise of even the best drivers may be distracting at high excursions.
Shape really makes little difference in a sealed cabinet below 100Hz, if you prefer the aesthetics of spherical constructs, your imagination and skills are the only limits.
What do you mean by "Brauer type sub grouping"?
Art
Sorry if it got lost in the mix.
This project is purely for listening pleasure in a listening room 🙂
Else Ill be forever analysing it instead of enjoying it lol
If I ever upgraded...which is hard when your ears are accustomed to a particular workflow, I would just use the spherical mix speakers get the SEAS kit/make masonry cabinets, using the AES dig in @ 192 and be done with it.
This negates the room and I stopped doing stereo subs about 10 years ago...1st and 2nd harmonics are the key. I have deliberated this for decades, back and forth, but I have worked out that the mentioned key is the best compromise...for me anyway...its aaallll a compromise.
The room sub does 30hz that but it does not convey accuracy anywhere near the utility of feeling it ie tactile and I def HP linear phase at 24db @20, its requested by studios for soundtracks.
So there is a bussing of
A B C D and some other aux
In my case, everything relevant that is below ie sub bass/kick etc has the original signals routed directly into it and they are crafted (dep on context) to work symbotically and without being affect by 1st and 2nd harmonic punch.
A = Subs of mainly Kick/Toms/Bass/Synth etc (bass is di signal and direct kick mic only)
B = Transient Harmonic eg drum kit, bass cab, Percussive guitar
C = Mid range orientate transient eg strings, acoustic guitar
D = Spatial, Synth, Backing vox
Vocals are completely on their own buss and direct route to mix buss...HTH
Thanks so much for your very detailed and valuable help
Thats exactly what i use for mixing, sealed single driver/concentric sealed and 2 way (atc) as industry standard workflow...was just for context
This project is purely for listening pleasure in a listening room 🙂
Else Ill be forever analysing it instead of enjoying it lol
If I ever upgraded...which is hard when your ears are accustomed to a particular workflow, I would just use the spherical mix speakers get the SEAS kit/make masonry cabinets, using the AES dig in @ 192 and be done with it.
Def...want to hear as long as possible.
I have been through this many times (studio setups)...thats why I use tactile...reasonable flat to 25 which, for commercial mixes is all shaved from 30hz upwards unless its soundtrack or something that makes use of those freq as they are a liability for mainstream release and a headroom sucker for more important ranges of current pop which is very 40-60hz centric.
This negates the room and I stopped doing stereo subs about 10 years ago...1st and 2nd harmonics are the key. I have deliberated this for decades, back and forth, but I have worked out that the mentioned key is the best compromise...for me anyway...its aaallll a compromise.
The room sub does 30hz that but it does not convey accuracy anywhere near the utility of feeling it ie tactile and I def HP linear phase at 24db @20, its requested by studios for soundtracks.
It has various incarnations (Beginnning with Michael Brauer) but instead of usual sub groups, it is based loosely on transient and freq range but is in no way a multiband treatment
So there is a bussing of
A B C D and some other aux
In my case, everything relevant that is below ie sub bass/kick etc has the original signals routed directly into it and they are crafted (dep on context) to work symbotically and without being affect by 1st and 2nd harmonic punch.
A = Subs of mainly Kick/Toms/Bass/Synth etc (bass is di signal and direct kick mic only)
B = Transient Harmonic eg drum kit, bass cab, Percussive guitar
C = Mid range orientate transient eg strings, acoustic guitar
D = Spatial, Synth, Backing vox
Vocals are completely on their own buss and direct route to mix buss...HTH
Thanks so much for your very detailed and valuable help
Think Nautilus or that kind of thing...artful biomimicry is always nice imo esp when its functional too
Looks like a Whale wang. They fetch around 6 grand in some markets.
Ironically the 100 grand Nautilus can go used around 6 to 8 grand.
Since they sit on the market for a loooooong time.
On a serious side these exotic shapes will just require fiberglass work.
And it would be funny to see how much a Nautilus actually rings.
You can buy overpriced fancy stuff from " Marine" suppliers or just get the same epoxy and cloth from 3M
I remember a few fiberglass copy threads for DIY endeavors on here. But dont have links.
I say they ring like a bell but were pretty cool 25? years or so ago.
Ironically the 100 grand Nautilus can go used around 6 to 8 grand.
Since they sit on the market for a loooooong time.
On a serious side these exotic shapes will just require fiberglass work.
And it would be funny to see how much a Nautilus actually rings.
You can buy overpriced fancy stuff from " Marine" suppliers or just get the same epoxy and cloth from 3M
I remember a few fiberglass copy threads for DIY endeavors on here. But dont have links.
I say they ring like a bell but were pretty cool 25? years or so ago.
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I think you might have missed some of the conversation and my main point...art is life. (and nautilus copies are like 2k on Alibaba)
I dont touch chemicals unless there is no choice. I cast a material I developed in a construction company in Australia that I use to own. It uses waste streams like the wood waste that no one else can use, geopolymers and food additives. It has been certified by CSIRO in Australia as one of the most fire resistant building materials and makes the cali fires look like a walk in the park (ie 46 deg C delta change on the passive side of the test wall, the other side at 1300c for 4 hours holding 10 ton per metre). Also near half the weight of concrete. It is proprietary as I saw patents pilfered by the exposure required at the outset and saw it as a more secure.
The reason why Im using it is we discovered it has serious energy absorption...a 50 cal goes nowhere penetrating 8" thick block but the most important thing is sound which is STC 51 for a standard building block. Along with being able to create organic molds with FDM, it is the perfect material and can say goodbye to the rectilinear forms and accompanying resonance of that geometry
There are no varnishes, no polyisocyanates in the finish...in fact you could almost eat it and it smells really nice as the scent of the cellulose (eg cedar) adds a slight aroma. I use corn based plastics for mold fabrication...every detail including what we do to the planet (and ourselves: its worth reading MSDSs)...it really does matter.
The Nautilus, I dont really see a point for but a VP...I do...as well as the sphericals (internally are tapered fusiform, I believe is the most non resonant analytic) I use are so out of the ballpark, they are mixing lens like no other and supplied with good stems, I can get a pretty decent mix going in 30 mins...no other speaker does this and everyone who comes into the studio is blown away. Its not audiophile but my point is...sometimes you just have to make the hard things easy and after a decade of casting, Im ready for a challenge 🙂
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