Hi,
I've been playing a bit this weekend, and found out that the design is noisy. anything under say 22Hz, starts to become 'flop flop flop' as soon as I cranked up the volume.
This happens before the driver starts to 'give up' (Which happens rather soon!) it hits Xmax quite quickly I think, going kgr kgrrr kgrrr.
I've done some rahter failed measurements, which show a 'bandpass like' curve, say 20 to 100 approx.
I'm way to unexpecienced to what's causing this, I can hardy distinct the diffrent types of distortion involved.
When playing 'breathe' of the DSOTM, the heartbeat 'bangs' but I think i't has some (unwanted) 'tick tick' (Hi freq) sound over it. Could be the driver hitting something.. (Xmax? Boundary? wood? )
My wife said, when playing it (too) loud (compared to the mains) that it sounds 'desagreable' (unconfortable), but then she sais that anytime I play rather loud bass. Could be things rattling in the room..?
Anyhow, I suggest someone with a larger range of drivers at hand, builds the box (Go for the 15 inch, as in the patent) and continues my (our collective) research/testing/measuring.
I'm pretty sure it goes way low, but it could end up being some or other bandpass design after all...
A little disencouraged, but nevertheless happy about this experiment,
Regards, Paul
PS: Continue, so will I!!
I second that...just a guy said:
I've been playing a bit this weekend, and found out that the design is noisy. anything under say 22Hz, starts to become 'flop flop flop' as soon as I cranked up the volume.
This happens before the driver starts to 'give up' (Which happens rather soon!) it hits Xmax quite quickly I think, going kgr kgrrr kgrrr.
I've done some rahter failed measurements, which show a 'bandpass like' curve, say 20 to 100 approx.
I'm way to unexpecienced to what's causing this, I can hardy distinct the diffrent types of distortion involved.
When playing 'breathe' of the DSOTM, the heartbeat 'bangs' but I think i't has some (unwanted) 'tick tick' (Hi freq) sound over it. Could be the driver hitting something.. (Xmax? Boundary? wood? )
My wife said, when playing it (too) loud (compared to the mains) that it sounds 'desagreable' (unconfortable), but then she sais that anytime I play rather loud bass. Could be things rattling in the room..?
Anyhow, I suggest someone with a larger range of drivers at hand, builds the box (Go for the 15 inch, as in the patent) and continues my (our collective) research/testing/measuring.
I'm pretty sure it goes way low, but it could end up being some or other bandpass design after all...
A little disencouraged, but nevertheless happy about this experiment,
Regards, Paul
PS: Continue, so will I!!
The model in the plans shows no attempt to isolate the unboxed side of the driver but the patent is pretty clear that the output from that side is not benefitial in any way. I think this accounts for the distortion seen in Bjorno's attachment 1 of the his last post.
TwisterZ's idea of mounting the driver outside of the listening room is great, but not always practical in some situations. Another way to address this issue may be a merging of technologies. Remember this thread, and this tiny subwoofer? http://www.diyaudio.com/forums/showthread.php?s=&threadid=89678 If you don't remember it and don't care to read through the thread or the patent, it uses a back chamber of very small proportions which actually performs more like IB. This idea could be very easily used to make a very small closed enclosure for the back side of the driver without pushing the fs of the driver/box combination higher.
The distortion I am referring to here, however, does not sound like the noise issue Bibster is describing. So I have to ask - have you glued and sealed all the sides on the box now? Even small air leaks can ruin the overall effect.
TwisterZ's idea of mounting the driver outside of the listening room is great, but not always practical in some situations. Another way to address this issue may be a merging of technologies. Remember this thread, and this tiny subwoofer? http://www.diyaudio.com/forums/showthread.php?s=&threadid=89678 If you don't remember it and don't care to read through the thread or the patent, it uses a back chamber of very small proportions which actually performs more like IB. This idea could be very easily used to make a very small closed enclosure for the back side of the driver without pushing the fs of the driver/box combination higher.
The distortion I am referring to here, however, does not sound like the noise issue Bibster is describing. So I have to ask - have you glued and sealed all the sides on the box now? Even small air leaks can ruin the overall effect.
Well,
I used these self-adhesive foam-strips one uses to sort of isolate door's edged etc.
Stuck that stuff one the 'not-glued' side of the box, and fimly screwed the 'lid' back on. I think this should do the trick, whilst still allowing access to the box's guts...
The 'outside edges' of the resonator, right in the corners/folds of the 'horn' are still very square, and the 'inside edges' at the same spot are NOT (yet) lined with some inverted quarter-round to smoothen them.
This might cause some noise...
Maybe this weekend I'll try to fix these issues, allthough I don't quite know how to fix the 'outside edges' problem: Hard to access all the way down to the glued-on lid.. (The inside edge can easyly be fixed by glueing in some routed stick or so.) I'll put the 2 braces (Pieces 'K') in as well: Might fix some noise INSIDE the resonator?
I must admit I have 2 cajons to finisch this weekend, so I'm not sure to have time...
If I do have time, I'll try to make some casing for the backside. Any hints for design/shape? Thanks,
Kind regards, Paul
I used these self-adhesive foam-strips one uses to sort of isolate door's edged etc.
Stuck that stuff one the 'not-glued' side of the box, and fimly screwed the 'lid' back on. I think this should do the trick, whilst still allowing access to the box's guts...
The 'outside edges' of the resonator, right in the corners/folds of the 'horn' are still very square, and the 'inside edges' at the same spot are NOT (yet) lined with some inverted quarter-round to smoothen them.
This might cause some noise...
Maybe this weekend I'll try to fix these issues, allthough I don't quite know how to fix the 'outside edges' problem: Hard to access all the way down to the glued-on lid.. (The inside edge can easyly be fixed by glueing in some routed stick or so.) I'll put the 2 braces (Pieces 'K') in as well: Might fix some noise INSIDE the resonator?
I must admit I have 2 cajons to finisch this weekend, so I'm not sure to have time...
If I do have time, I'll try to make some casing for the backside. Any hints for design/shape? Thanks,
Kind regards, Paul
Image "G" in the patent shows the back box as a dotted line. I think just making a box the same size as the top of your speaker baffle board and about the volume of the resonator should work. You might want to use speaker modeling software for a sealed box for the driver specs you are useing. The only thing that bothers me is how the restrictor between the woofer and the resonator is going to effect the woofers T/S parameters.
johninCR said:Gex,
The natural progression should have been from BassBoy to BassMan, but since there's much more expertise on this board, he decided to be Just a Guy. BassMan.
Much more expertise is a definite.
that makes me bass-"a twinkle in my daddys eye" if your the bassbaby.
I just hang out to read the Bass threads. I would not be able to answer any questions on the "other" forum without this place. lol
I am just waiting to see if anything good comes of this. Not really building anymore but you just never know.
Gex
Just found this topic 14 days agoe, and have read just about everything thats on the veb. But I am still no surre how it works.
I am wondering can this princip work whit a full range speaker, I am useing a par of Fostex F200A in MLTL whit a Tact RC2.0 and thy are great.
But if I can make them work fram 5Hz-20KHz it whold be great.
Any idaers, sorry for my spellings
Frank
I am wondering can this princip work whit a full range speaker, I am useing a par of Fostex F200A in MLTL whit a Tact RC2.0 and thy are great.
But if I can make them work fram 5Hz-20KHz it whold be great.
Any idaers, sorry for my spellings
Frank
This design is a subwoofer only. You could integrate this sub into another system, but on it's own there is no way this design will get down to 5 hz with a small fullrange driver. Also, response will not be flat enough to extend up to 20khz (or anywhere close to that). Fullrange drivers are not appropriate for this design in any way.
Hi,
Look at the submitted picture where a 10” Dayton speaker driver http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=295-460 is modeled in a double bas reflex (BIB?) enclosure, capable in room SPL of more than 90 dB at 8 Hz and low ripple that any room will hide.
Not a Holiman but this less than 1 Litres total stroke-volume (2 x X-max x Sd) 10” based infra DBR driver covers 8 - 80 Hz and will work in any room because of the built in air velocity conversion. J
The size is quite large (427 L), but more than + 8dB is gained at 8 Hz compared to the corresponding IB type and the driver is within linear X-max with a low 16 W RMS input when producing 90 dB SPL at 8 Hz.
With typical + 9dB ‘room gain’ at 10 Hz an f-3dB at 6 Hz can be expected in most living rooms even if doors not are closed.
B
Look at the submitted picture where a 10” Dayton speaker driver http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=295-460 is modeled in a double bas reflex (BIB?) enclosure, capable in room SPL of more than 90 dB at 8 Hz and low ripple that any room will hide.
Not a Holiman but this less than 1 Litres total stroke-volume (2 x X-max x Sd) 10” based infra DBR driver covers 8 - 80 Hz and will work in any room because of the built in air velocity conversion. J
The size is quite large (427 L), but more than + 8dB is gained at 8 Hz compared to the corresponding IB type and the driver is within linear X-max with a low 16 W RMS input when producing 90 dB SPL at 8 Hz.
With typical + 9dB ‘room gain’ at 10 Hz an f-3dB at 6 Hz can be expected in most living rooms even if doors not are closed.
B
Attachments
Thanks for the replays.
My idea was to minimize the travel of the speaker units at low frequencies. The Fostex F200A units are limited to -/+ 2mm. liner.
To just a guy: The Tact room correction will take care of any peek’s and bump’s.
I have set the tasked curve to 20Hz to 20KHz on the Tact, this give me a –3dB around 18Hz. This normally works fine, but some music contains frequencies as low as 5-10 Hz and this is where the Xmas is excited.
I know that it is much to ask for, for a 20 cm full range unit. I have tried whit many sub’s but never
found a set-up that work properly
My idea was to minimize the travel of the speaker units at low frequencies. The Fostex F200A units are limited to -/+ 2mm. liner.
To just a guy: The Tact room correction will take care of any peek’s and bump’s.
I have set the tasked curve to 20Hz to 20KHz on the Tact, this give me a –3dB around 18Hz. This normally works fine, but some music contains frequencies as low as 5-10 Hz and this is where the Xmas is excited.
I know that it is much to ask for, for a 20 cm full range unit. I have tried whit many sub’s but never
found a set-up that work properly
Greets!
Haven't had time to do much other than a quick skim of the thread, but FWIW I did a BP sim for someone awhile back that will more than meet any sane person's raw performance requirements IMO, though for such low frequencies it takes inches and $$^3:
11.11 ft^3 net rear chamber
5.5 ft^3 net front chamber
8" diameter x 30" long vent
If this new Tumult's specs are as accurate as other Adire drivers have historically been, then it doesn't run out of Xmax till somewhere below 5 Hz at its 1.0 kW power rating, so assuming the room can contain such low frequencies it should generate them at >103 dB until the VCs heat up enough to raise Qts an appreciable amount. Really, if the room is strong enough to have gain this low, then you could probably get away with as little as a 5.5 ft^3 rear chamber and a somewhat shorter vent.
GM
Haven't had time to do much other than a quick skim of the thread, but FWIW I did a BP sim for someone awhile back that will more than meet any sane person's raw performance requirements IMO, though for such low frequencies it takes inches and $$^3:
11.11 ft^3 net rear chamber
5.5 ft^3 net front chamber
8" diameter x 30" long vent
If this new Tumult's specs are as accurate as other Adire drivers have historically been, then it doesn't run out of Xmax till somewhere below 5 Hz at its 1.0 kW power rating, so assuming the room can contain such low frequencies it should generate them at >103 dB until the VCs heat up enough to raise Qts an appreciable amount. Really, if the room is strong enough to have gain this low, then you could probably get away with as little as a 5.5 ft^3 rear chamber and a somewhat shorter vent.
GM
Attachments
Bjorno's proposed dual reflex box: I love the range - 8 hz to 80 hz is incredible. I don't like the size so much, as this box is larger than the largest Holliman box and it would take 4 or 5 of them to get as loud as GM's bandpass
GM's bandpass: size vs output ratio is much better than Bjorno's box but frequency range is limited. The bandpass will get a lot louder, but that's because it's a much more capable driver in terms of displacement.
Ascendant Alliance ported: I did some WinISD sims with the Ascendant replacement for the Avalance 18, the Alliance 18 HT sub (although this model seems to be discontinued at this time as well). It had a 14 hz fs and sold for about $400 I think. The WinISD -6db EBS ported box was large (about 45 cubic feet) and tuned to somewhere around 10 hz. I think I remember excursion limited output of about 110 db (maybe more) with a couple hundred watts. This sub would be down 6 db at 10 hz, compared to Bjorno's and GM's which are down at least 9 db at 10 hz.
I realize there are other infrabass options worth discussing. For example, the Ascendant Alliance driver (if you could get it) would probably outperform my WinISD ported models in either Bjorno's dual reflex or GM's bandpass (modified to suite driver, of course). It is the most capable driver I have seen to date for low tuning; flatter and lower than the Avalanche despite less Xmax. I am really interested to see what Ascendant replaces it with. This, or something like it, would be my driver of choice for infrabass applications. The box is going to have to be huge, no matter what type, but it puts out enough to make it worth it and the low fs ensures it will go lower, flatter than any of it's competition (that I know about, hopefully this will change).
I think these characteristics are important because at these low frequencies, the accumulated roll off of the system (source, active XO, amp, etc) will negate the bottom end boost you would expect to see from room gain. I don't want to be more than 6 db down at 10 hz, I'd rather have to eq down than try to eq the low end up.
The whole point of the Holliman experiment was to see what is possible with smaller sizes and cheaper components. 4 Daytons, or 1 Tumult, or 1 Alliance and a box to hold them are a considerable investment in terms of cost and space. An Alliance in a low tuned dual reflex would be the size of a closet. The Holliman 15 is the smallest of all the boxes discussed here. I'm still interested to see what it is actually capable of.
GM's bandpass: size vs output ratio is much better than Bjorno's box but frequency range is limited. The bandpass will get a lot louder, but that's because it's a much more capable driver in terms of displacement.
Ascendant Alliance ported: I did some WinISD sims with the Ascendant replacement for the Avalance 18, the Alliance 18 HT sub (although this model seems to be discontinued at this time as well). It had a 14 hz fs and sold for about $400 I think. The WinISD -6db EBS ported box was large (about 45 cubic feet) and tuned to somewhere around 10 hz. I think I remember excursion limited output of about 110 db (maybe more) with a couple hundred watts. This sub would be down 6 db at 10 hz, compared to Bjorno's and GM's which are down at least 9 db at 10 hz.
I realize there are other infrabass options worth discussing. For example, the Ascendant Alliance driver (if you could get it) would probably outperform my WinISD ported models in either Bjorno's dual reflex or GM's bandpass (modified to suite driver, of course). It is the most capable driver I have seen to date for low tuning; flatter and lower than the Avalanche despite less Xmax. I am really interested to see what Ascendant replaces it with. This, or something like it, would be my driver of choice for infrabass applications. The box is going to have to be huge, no matter what type, but it puts out enough to make it worth it and the low fs ensures it will go lower, flatter than any of it's competition (that I know about, hopefully this will change).
I think these characteristics are important because at these low frequencies, the accumulated roll off of the system (source, active XO, amp, etc) will negate the bottom end boost you would expect to see from room gain. I don't want to be more than 6 db down at 10 hz, I'd rather have to eq down than try to eq the low end up.
The whole point of the Holliman experiment was to see what is possible with smaller sizes and cheaper components. 4 Daytons, or 1 Tumult, or 1 Alliance and a box to hold them are a considerable investment in terms of cost and space. An Alliance in a low tuned dual reflex would be the size of a closet. The Holliman 15 is the smallest of all the boxes discussed here. I'm still interested to see what it is actually capable of.
Has anyone considered placing the driver in the chamber to give it a sealed box? This would allow the placement of another box on the other side of the port which gave the Holliman effect to tune with. It could be sealed (as in the picture I have uploaded) or ported or near-free with a passive radiator.
EDIT
Alternatively passive radiators could be attached to the sides of the sealed chamber causing the port volumes to "flex" for a slightly "wider" tuning frequency, or to knock off peaks.
EDIT
Alternatively passive radiators could be attached to the sides of the sealed chamber causing the port volumes to "flex" for a slightly "wider" tuning frequency, or to knock off peaks.
Attachments
Graham holliman
This appears to be worthy of a little expreimentation. From your drawing I'm assuming that you would build the enclosure and duplicate everything except the placement of the driver baffle and the chamber on top of the enclosure.
What would be the advantage of a ported or near free chamber? Wouldn't using a pair of PR's decease eficiency except at the pr's resonant frequency? something like a 18db rolloff at 6hz away from the pr's RF?
Of course if tuned properly, the resonant frequencies of the separate PR's could be spaced far enough apart to gain bandwidth. Though I do not know if the resonant frequency of the opposing chamber is the upmost factor in the tuning of a GH enclosure.
Is anyone else going to try this?
This appears to be worthy of a little expreimentation. From your drawing I'm assuming that you would build the enclosure and duplicate everything except the placement of the driver baffle and the chamber on top of the enclosure.
What would be the advantage of a ported or near free chamber? Wouldn't using a pair of PR's decease eficiency except at the pr's resonant frequency? something like a 18db rolloff at 6hz away from the pr's RF?
Of course if tuned properly, the resonant frequencies of the separate PR's could be spaced far enough apart to gain bandwidth. Though I do not know if the resonant frequency of the opposing chamber is the upmost factor in the tuning of a GH enclosure.
Is anyone else going to try this?
You know I wonder why more people are not spending more time building and testing.
If you have the time to think about this stuff as much as you do you have the time to build it.
I got shut down on this stuff and subs are a curse word now that I rattled one to many wall and brain matter.
The most complicated project I have done lately without trouble was a 10" broken legend sub that went to a Mach 12" and retuned port and a smaller amp. I did it at work over a couple weeks ( thats just sad)
Somebody here much have more time and freedom than that. If you have a dual voice sub that will allow more flexibility in parameters.
I also have no idea why all of a sudden a thread I have not seen in months showed up in my mailbox when I unchecked it a long time ago.
But anywayit still cool that its being discussed
If you have the time to think about this stuff as much as you do you have the time to build it.
I got shut down on this stuff and subs are a curse word now that I rattled one to many wall and brain matter.
The most complicated project I have done lately without trouble was a 10" broken legend sub that went to a Mach 12" and retuned port and a smaller amp. I did it at work over a couple weeks ( thats just sad)
Somebody here much have more time and freedom than that. If you have a dual voice sub that will allow more flexibility in parameters.
I also have no idea why all of a sudden a thread I have not seen in months showed up in my mailbox when I unchecked it a long time ago.
But anywayit still cool that its being discussed
Unfortunately I do not have the time to build things since i'm usually working. I use conundrums such as this to keep my mind busy so I dont go nuts doing menial tasks.
Shop work right now, but during seeding and harvest I dare you to spend a couple months going in circles or back and forth over a couple thousand acres at 2-15mph for 8-20 hours per day
Back on topic.. I was thinking further on this and the orientation of the driver (ie: which side of the Holliman port (can I call it that? lol)) probably doesnt matter. It might make the difference between a home installation and a "wicked-one" setup capable of fitting in a vehicle, though.
The passive radiators intruding into the port volumes (more correct to call them horns possibly?) may restrict or increase air pressure or velocity in the horns adding bandwidth. I dont know if tunning each side to a different bandwidth would be good. Does anyone have examples of this being done with a single driver and multiple air paths?
The Holliman chamber (for sake of easy references) being sealed vs. free-air needs experimentation. As referenced earlier in the thread you can blow over a sealed milk jug and get sound. What if you cut the bottom off and blow over the now free-air milk jug? Can we tue this extra chamber? What if we put another driver in it and increased the neck length for an isobarik style setup?
Does the neck length of the holliman chamber matter, or do you want it as thin as possible into its air volume?
Shop work right now, but during seeding and harvest I dare you to spend a couple months going in circles or back and forth over a couple thousand acres at 2-15mph for 8-20 hours per day
Back on topic.. I was thinking further on this and the orientation of the driver (ie: which side of the Holliman port (can I call it that? lol)) probably doesnt matter. It might make the difference between a home installation and a "wicked-one" setup capable of fitting in a vehicle, though.
The passive radiators intruding into the port volumes (more correct to call them horns possibly?) may restrict or increase air pressure or velocity in the horns adding bandwidth. I dont know if tunning each side to a different bandwidth would be good. Does anyone have examples of this being done with a single driver and multiple air paths?
The Holliman chamber (for sake of easy references) being sealed vs. free-air needs experimentation. As referenced earlier in the thread you can blow over a sealed milk jug and get sound. What if you cut the bottom off and blow over the now free-air milk jug? Can we tue this extra chamber? What if we put another driver in it and increased the neck length for an isobarik style setup?
Does the neck length of the holliman chamber matter, or do you want it as thin as possible into its air volume?