Little update:
Even if the cabinet size is much bigger than planned, i'd like to test a tapped horn with a 8'' driver (the biggest nominal size that is offering a fighting chance for sub-100 liters size)
Played with hornresp and it looks like 118-125db is achievable with only a single 8'', anywhere between 27 and 31hz, at max power and xmax. Which is truly fantastic. At least on paper (sim)...
Even if the cabinet size is much bigger than planned, i'd like to test a tapped horn with a 8'' driver (the biggest nominal size that is offering a fighting chance for sub-100 liters size)
Played with hornresp and it looks like 118-125db is achievable with only a single 8'', anywhere between 27 and 31hz, at max power and xmax. Which is truly fantastic. At least on paper (sim)...
I'm not sure yet if i will build and test ALL of them, but the upcoming comparison looks like this:
SEALED (1) 15W0v3
SEALED (2) 12WXv2
TAPPED HORN (1) 8W7 or L7S8 or Ultimax 8''
Also BR (port or passive radiators) cabinets versions which any of those drivers.
All between 60 and 100 liters cabinet and all within reasonable budget (except the 8W7)
........
I could try some bandpass 4th and 6th order as well but the bandwith is more limited than TH and maybe not on par with it too ''liter-for-liter, watt-for-watt''.
Never experimented TH in my life but for what i heard it's the best ''28-35hz'' solution if you can live with the mandatory subsonic filter + steep low pass and EQ... And cabinet size, of course.
SEALED (1) 15W0v3
SEALED (2) 12WXv2
TAPPED HORN (1) 8W7 or L7S8 or Ultimax 8''
Also BR (port or passive radiators) cabinets versions which any of those drivers.
All between 60 and 100 liters cabinet and all within reasonable budget (except the 8W7)
........
I could try some bandpass 4th and 6th order as well but the bandwith is more limited than TH and maybe not on par with it too ''liter-for-liter, watt-for-watt''.
Never experimented TH in my life but for what i heard it's the best ''28-35hz'' solution if you can live with the mandatory subsonic filter + steep low pass and EQ... And cabinet size, of course.
A little precision about the title of this thread:
''between 28-35hz'' means the Q, not anywhere between 28-35hz as a starting point for a flat response.
Of course, that's obviously difficult to achieve with a TH and limited cabinet size. Simulations i did so far was very peaky (sometimes 8db+ within only 1/3 octave).
For me, that's not really a problem but only if it's below 30hz. I wouldnt want a peak at 35hz, but a peak at 28hz would be OK as it enters the ''pressurisation'' territory rather than ''boomy'' territory.
''between 28-35hz'' means the Q, not anywhere between 28-35hz as a starting point for a flat response.
Of course, that's obviously difficult to achieve with a TH and limited cabinet size. Simulations i did so far was very peaky (sometimes 8db+ within only 1/3 octave).
For me, that's not really a problem but only if it's below 30hz. I wouldnt want a peak at 35hz, but a peak at 28hz would be OK as it enters the ''pressurisation'' territory rather than ''boomy'' territory.
Jon,
Your answer sounds very much like you have never experienced "this technology"(tactile transducers) to me ;^).
Art
Nothing wrong with tactile transducers, they have their uses.
I wish you luck on the TH project, for some reason many people here seem to prefer TH's, sounds very impressive for a while, but they are not for me. BR can be a viable compromise provided it is done correctly. Sealed sounds very good in the right settings. OB sounds good too, but they can be a bit "demanding". TH is maybe 5th or 6th on my list over preffered enclosure types.
Do not want to come off as "Captain Obvious", but here goes anyway:
Please pay attention to Group delay, phase and acoustic impedance, at least if you have any intention at all to achieve some measure of fidelity when incorporating the finalized design in your system. And you may get some output below acoustic impedance peak, but it is usually the point of rapid falling response.
I wish you luck on the TH project, for some reason many people here seem to prefer TH's, sounds very impressive for a while, but they are not for me. BR can be a viable compromise provided it is done correctly. Sealed sounds very good in the right settings. OB sounds good too, but they can be a bit "demanding". TH is maybe 5th or 6th on my list over preffered enclosure types.
Do not want to come off as "Captain Obvious", but here goes anyway:
Please pay attention to Group delay, phase and acoustic impedance, at least if you have any intention at all to achieve some measure of fidelity when incorporating the finalized design in your system. And you may get some output below acoustic impedance peak, but it is usually the point of rapid falling response.
Never even heard one sample. Can't wait to try it.
What concerns me the most, is the audible noise artefacts potentially coming from the back of the driver... Usually the backwave is contained inside a cabinet and such noises are not too obvious (unless through a vent and without filling) but i think the right selection of driver is important here.
Hi,
I didn't read the whole thread, but to answer the question in the title: Der Niwo-Max-Eckhorn Thread, Subwoofer - HIFI-FORUM
And if one doesn't destroy your house -> build a second one
Greetings
E: Of course you will need a corner where you can put it in....
I didn't read the whole thread, but to answer the question in the title: Der Niwo-Max-Eckhorn Thread, Subwoofer - HIFI-FORUM
And if one doesn't destroy your house -> build a second one
Greetings
E: Of course you will need a corner where you can put it in....
Hi can anyone tell me which 6th order reflex kind of driver/enclosure/port arrangement is keele paper about (from djk link and post) ? I read paper (but no schematic figure inside): keele talks of a third case being 6th order reflex (compared to single reflex and closed) :
a 6th order bandpass or a 6th order series tuned reflex or something else ?
thanks
a 6th order bandpass or a 6th order series tuned reflex or something else ?
thanks
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A tactile device will not reproduce the feeling of "real sound waves" at 150 dB SPL between 30Hz and 70Hz, but a small tapped horn using an 8" driver will be also be about 30 dB SPL short of that feeling. If you want to "feel" the sound, you something that moves your viscera, and it takes a lot of SPL to do that, but not much mechanical force.I have experience with Aura bass shakers and also real ''sound waves'' 150db SPL anywhere between 30hz and 70hz.
I don't think any tactile device would be able to reproduce that feeling, or prove me wrong.
TH can extract more SPL from a given driver at a given excursion, at the expense of distortion, cabinet volume and a ragged out of band response.
Good luck,
Have Fun!
Art
Jon,
The Data Bass comparison was between a dual driver TH ten times the volume of the single driver ported cabinet, and 24 times the volume of the single driver sealed cabinet. Excursion was not mentioned in Josh's test, I specifically wrote "a TH can extract more SPL from a given driver at a given excursion"- in my Keystone thread you can see the results of a BC18SW115-4 run with the same voltage in BR and TH alignments, and the measured excursions at the test frequencies. For a given excursion, the TH has more distortion, but almost 6 dB more output, but using a larger cabinet.
If you have room for a 24.24 cubic foot TH, the results can be impressive.
If you have a limited volume to work with, using multiple drivers each adequately powered, a higher output with less distortion can be realized in a BR alignment with the same Fb over a single driver TH.
Cheers,
Art
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Yes, you are floating where the angelic choirs will sing their siren songs, and you get to decide which sounds best to you
.
Yes, you are floating where the angelic choirs will sing their siren songs, and you get to decide which sounds best to you
Hahahah!
:-D
Regarding tactile transdusers have their uses:
What I was thinking about was for instance when they are mounted to a comfy chair close to a nice headphone setup. Just put your legs up, read a good book together with a long classical playlist. You sometimes forget you are listening with headphones and fake sub bass if it's comfortable enough.
Some say it's not worth it to go TH unless you can get a sim with an extra 6db over BR...
Well, so far BR wins with a target of 28hz (more or less 24hz F3) with the drivers i'm planning to use. Only get 3-4db extra with the TH and that's very peaky, plus slightly higher cut-off.
Good 'ol bass reflex, uh?
Well, so far BR wins with a target of 28hz (more or less 24hz F3) with the drivers i'm planning to use. Only get 3-4db extra with the TH and that's very peaky, plus slightly higher cut-off.
Good 'ol bass reflex, uh?
Yeah, and they won't shut up about it right? The problem is that this statement is somewhere between very misleading and outright false.
Resonant gain is all about enclosure size so if you build a horn (of any type) the same size as a ported box with the same tuning you won't see much if any benefits over the ported box.
BUT if you make the horn much larger you will see your benefits. In a lot of cases the good tapped horns are 4x or more larger than a ported box for the same tuning.
Here's an extreme example to make a point, extreme examples give extreme results (although I could have made an even more extreme example).
This is a 170 liter ported box vs a 4800 liter tapped horn with the same driver and the same low knee frequency, both with 1 watt input. 1 actual watt.
But why you say? Why are the input voltages different if they are both getting 1 watt? I'll show you. I'm applying 1 watt at the impedance minimum in a sub's passband. The tapped horn is large so it raises the impedance minimum to about 7.5 ohms while the ported box has a minimum impedance of about 5.5 ohms. Big difference, this is partly why extreme examples give extreme results. TH impedance on the left, ported on the right.
Now look at the sensitivity difference in these two boxes, you've got a solid 10+ db advantage from the larger box, as expected. And I could show MUCH greater differences, probably in excess of 20 db, this was just a super quick 2 minute sim.
The whole point is that if you want a sensitivity gain you NEED to make the horn much larger than the ported box. There's no rule about 6 db or don't bother, it all depends on how big you want to go.
Also, most people make ported boxes with VASTLY undersized ports so there's a huge amount of port compression at high power levels. Horns don't have much of an issue with that, so even if you had a horn sim and a ported sim that seemed head to head (same sensitivity) at high power the horn would most likely smoke the ported box on the order of maybe 6 db due to the lack of port compression.
And there's also power compression. The tapped horn driver is usually in a very well ventilated area and it usually takes less power for a tapped horn to reach xmax than a ported box so there could be pretty large power compression losses for the ported box that the tapped horn won't experience.
There's a lot of things going on. Don't listen to people that insist there are simple rules you need to follow. You need to understand the acoustic behavior, not follow simple rules that don't make much sense without context.
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Quite.
Just running the same scenario:
You can fit 28 of those BR boxes in the same volume.
16 of said BR boxes will provide near 0db down to a hair over 30hz while providing near-identical sensitivity.
The power draw of the BR boxes will be comparable to the TH.
The phase response and group delay of the TH will have big variations.
The phase response and group delay of the BR will be insignificant.
Power response is limited to voltage (set it to max 55V) on the 16*BR boxes when 4*series 4*parallell, reaching 132db at 40hz and no need for HP filters at all because xmax is merely tickled, power draw is not a concern pr driver, because the load is distributed.
The TH MUST HAVE a steep HP filter at 36hz or the driver will be destroyed, providing 133db at 40hz and requiring 300-450watts of power over the freq range inducing some loss due to compression from heat.
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Of course 28 BR's can be placed in the volume of that single TH maybe less if you cleverly fold the horn. JAG was pointing out it was an extreme example. But if we are expanding the extremes to a larger picture and take the footprint differences; 28 drivers vs 1, more trees need to be cut to supply all the wood for the 28 br's, more paint, amps, cables, plugs and mains power needs.
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