Hi Aceinc: The Tapped Horn is a very demanding box, that requires the driver to have a specific balance of T/S values. Some drivers do well with the taps at the throat and the mouth, while others require the taps to be well away from both.
Most drivers don't do well at all.
I had hoped that David McBean, or Tom Danley ... (or anybody) would give us a simple calculation that would allow us to qualify a driver as acceptable / unacceptable for a tapped horn. Perhaps some calculation involving CMS and BL would do it.
For the time being, we'll just have to plug values into Hornresp until something works.
Most drivers don't do well at all.
I had hoped that David McBean, or Tom Danley ... (or anybody) would give us a simple calculation that would allow us to qualify a driver as acceptable / unacceptable for a tapped horn. Perhaps some calculation involving CMS and BL would do it.
For the time being, we'll just have to plug values into Hornresp until something works.
got the wood cut today, its a real shame but they didn't have 25mm mdf so i had to downscale to 18mm, just have to use some serious bracing now 
and its now dawned on me just how big this thing really is, its giant, when u seem something in reality as apposed to your imagination, it makes u think, man maybe this is to crazy
gotta do it though
will be fine in the corner......
and its now dawned on me just how big this thing really is, its giant, when u seem something in reality as apposed to your imagination, it makes u think, man maybe this is to crazy
gotta do it though
will be fine in the corner......
>The Tapped Horn is a very demanding box, that requires the driver to have a specific balance of T/S values.
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True, and why using other than measured specs of your driver is a crapshoot at best WRT how well it matches the sim. For HIFI apps though, the room dominates, so I personally can't get too worked up over how flat the sim is.
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>Some drivers do well with the taps at the throat and the mouth, while others require the taps to be well away from both.
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Right, assuming you're trying to get the max HF BW out of it, then the higher the driver's mass corner (Fh), the closer to the ends it needs to be.
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>Most drivers don't do well at all.
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Well, within reason they can all be made to work, just maybe not in the particular BW we're most interested in.
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>I had hoped that David McBean, or Tom Danley ... (or anybody) would give us a simple calculation that would allow us to qualify a driver as acceptable / unacceptable for a tapped horn.
=====
Simple band-pass theory works well enough for me and manipulating Prof. Leach's horn math gets me the throat, etc. and why my sims are typically somewhat larger than some other's that seem to me to be more trial n' error Hornresp derived than based on any specific BP/horn design routine, though feel free to prove me wrong.
GM
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True, and why using other than measured specs of your driver is a crapshoot at best WRT how well it matches the sim. For HIFI apps though, the room dominates, so I personally can't get too worked up over how flat the sim is.
=====
>Some drivers do well with the taps at the throat and the mouth, while others require the taps to be well away from both.
=====
Right, assuming you're trying to get the max HF BW out of it, then the higher the driver's mass corner (Fh), the closer to the ends it needs to be.
=====
>Most drivers don't do well at all.
=====
Well, within reason they can all be made to work, just maybe not in the particular BW we're most interested in.
=====
>I had hoped that David McBean, or Tom Danley ... (or anybody) would give us a simple calculation that would allow us to qualify a driver as acceptable / unacceptable for a tapped horn.
=====
Simple band-pass theory works well enough for me and manipulating Prof. Leach's horn math gets me the throat, etc. and why my sims are typically somewhat larger than some other's that seem to me to be more trial n' error Hornresp derived than based on any specific BP/horn design routine, though feel free to prove me wrong.
GM
Oliver:
I will try what you suggested when I get home. What affect will the inductor have on the FR? Act as a low pass filter?
GM:
The 10" Titanic has a small VAS, and a moderate FS, does this seem like it might work for a TH? I would like to slide the FR window down towards 18-20hz if possible.
Paul
I will try what you suggested when I get home. What affect will the inductor have on the FR? Act as a low pass filter?
GM:
The 10" Titanic has a small VAS, and a moderate FS, does this seem like it might work for a TH? I would like to slide the FR window down towards 18-20hz if possible.
Paul
GM said:Simple band-pass theory works well enough for me and manipulating Prof. Leach's horn math gets me the throat, etc. and why my sims are typically somewhat larger than some other's that seem to me to be more trial n' error Hornresp derived than based on any specific BP/horn design routine, though feel free to prove me wrong.
GM
Trial and error works great for me. You get a good feeling what will work or how to alter something to get it work after a few hundred simulations
Would this driver be suitable for use in a car sub?
http://www.partsexpress.com/pe/pshowdetl.cfm?Partnumber=295-364
http://www.partsexpress.com/pe/pshowdetl.cfm?Partnumber=295-364
454Casull said:
Personally, I would avoid using that driver for a auto tapped horn. Because of cabin gain, tapped horns in a car need a whole different set of parameters than a tapped horn for a house or live venue.
Basically, you need to tailor the response so it decays gradually. The droop in response will be filled in by the car's cabin gain.
Also, the woofer you posted has a relatively low xmax.
If I were making a tapped horn for a car, I'd look at a woofer with a very low QTS value and a FS in the 30s or 40s. You can never have too much xmax.
Another option is to simply use EQ to reduce the low frequency output that cabin gain delivers. Either option is viable.
GM:
Say I wanted to acheive the highest quality sub below 80 hz with a LFR of below 19hz. I am willing to sacrifice high bass freq (+60 hz) to acheive sub 20hz response. I would like to keep cabinet complexity within the capabilities of a dilitante.
I have two scenarios for you.
1) Assume that neither size nor price mattered, in other words I would buy the optimal driver(s), and build the optimal sized cabinet irrespective of price or size. The only thing I ask is that the drivers are readily available in the US.
2) Using either the 10" Titanic I mentioned in post 1720, or the 10" xplod I mentioned in post 1533, size is no object, what would the best design be? I have a pair of each.
After I get the acoustical design, I will need to determine how best to fold it. My options are to build it tall and put it into a builtin type of cabinet, or lay it flat and make a seat under a "bay window"
My wife is understanding to a point. If I can make it fit into the decor she doesn't argue.
This would replace a 3 cu. ft sealed Rythmik Audio DS15. One thing I have been wondering, is how would a servo driver such as the RA DS12 work in a tapped horn? I wish I had lots of time to play with this stuff... But if I had lots of time, I wouldn't have the money...
Paul
Say I wanted to acheive the highest quality sub below 80 hz with a LFR of below 19hz. I am willing to sacrifice high bass freq (+60 hz) to acheive sub 20hz response. I would like to keep cabinet complexity within the capabilities of a dilitante.
I have two scenarios for you.
1) Assume that neither size nor price mattered, in other words I would buy the optimal driver(s), and build the optimal sized cabinet irrespective of price or size. The only thing I ask is that the drivers are readily available in the US.
2) Using either the 10" Titanic I mentioned in post 1720, or the 10" xplod I mentioned in post 1533, size is no object, what would the best design be? I have a pair of each.
After I get the acoustical design, I will need to determine how best to fold it. My options are to build it tall and put it into a builtin type of cabinet, or lay it flat and make a seat under a "bay window"
My wife is understanding to a point. If I can make it fit into the decor she doesn't argue.
This would replace a 3 cu. ft sealed Rythmik Audio DS15. One thing I have been wondering, is how would a servo driver such as the RA DS12 work in a tapped horn? I wish I had lots of time to play with this stuff... But if I had lots of time, I wouldn't have the money...
Paul
aceinc said:I am playing Hornresp 1910-080422. I decided to see what I can do with some Dayton Titanic III 10" specs. I used the Parts Express DuMax report rather than the MFR specs.
I sure as heck can't get the pretty flat curves you guy's seem to get. Can someone please point me in the right direction?
Below is what I have so far.
I chose the Titanics because I currently have two in small sealed enclosures begging to be set free.
Paul
If you think that 2db dip is bad, you'd cry if you knew how inaccurate published specs are. I've never measured a single driver that was even in the BALLPARK of published specs. The only exception I've found were prosound drivers like Galaxy Audio and B&C.
so....
I'd go and spend $100 on a PE woofer tester before making any sawdust. When you're done with your project, just sell it on ebay for $80.
Naudio said:
Hi Naudio,
Can you provide me with some details of the problem you are experiencing? I would like to help if I can.
My email address is dmcbean@bigpond.com
Thanks,
David
aceinc, go look at Erik's design in post 666 and also a few posts later. Eminence 3015LF driver and huge output potential to 20Hz with a $US180 driver. Also check out his site www.volvotreter.de -> Tapped Horn and the drawings for it in the download section.
thats a phenomenal low end extension, killjoy, but the high frequency ripple is really ugly. i dont know how important it is, but i like plots which fall down on both ends of the passband.
William Cowan recommended the peerless xxls car audio driver 830877 to me, which i used in the following sim. Its much bigger than yours and doesnt go as low, but meets aceincs specs.
now if you could get a plot like this one, only half an octave lower, then i would be really happy.
William Cowan recommended the peerless xxls car audio driver 830877 to me, which i used in the following sim. Its much bigger than yours and doesnt go as low, but meets aceincs specs.
now if you could get a plot like this one, only half an octave lower, then i would be really happy.
Attachments
Hi - Frequency Ripple
Hello MaVo:
I agree about the ripples. I have some ideas about how I will deal with those but I am working them out with a smaller test horn. I still like the idea of using an extreme slope x-over (120db). Even in your sim I beleive there will be some evidence of the higher frequency ripples in the response that may lead to distortion.
I just spent a week reading the "Beyond the Ariel" post started by Lynn Olson so now I can talk about stuff that sounds good but I don't know a lot about
I also think I spend way to much time playing around with THs in Hornresp.
Hello MaVo:
I agree about the ripples. I have some ideas about how I will deal with those but I am working them out with a smaller test horn. I still like the idea of using an extreme slope x-over (120db). Even in your sim I beleive there will be some evidence of the higher frequency ripples in the response that may lead to distortion.
I just spent a week reading the "Beyond the Ariel" post started by Lynn Olson so now I can talk about stuff that sounds good but I don't know a lot about
I also think I spend way to much time playing around with THs in Hornresp.
nope its fine, there are no probs, oliver did a simulation of my horn in a newer version of horn resp, and when i coyed the input info over it put the horn mouth at the end of the first expansion, thats all
all the woods cut, driver hole cut, will begin to assemble tomorrow
i kinda stood the planks together in a box shape today with the speaker in to test, i found that there was no 20hz bass
then i push down on a small crack and i hear some, then i squeeze another corner and even more, then i sit on it, wow now were talking... then the top end rattles off, and air is flying out here there and everywhere, not a good idea, dam my impatiences, just wish i wasn't working all week,
so i defiantly need loads of strategic but streamlined bracing, i have a tube of no more nails sealant that i will run over every single edge imaginable.
anyway i am taking pics of the construction from start to finish, and will post up the final plan and input info, along with a nice slideshow of construction, and my review, this will be good for anyone looking to build a sub the lazy way (using someone else's hard work) but i dont mind, u guys helped me enough.....
i don't think the sound that isn't simulated in horn resp as flat, is necessary distorted, it just has peeks and dips, there is a big difference there, my sim only shows peeks of 5db, and room peeks and dips are alot bigger
do a test, play a note like 70hz or 100hz using a generator, walk around the room, there will be places u hear it really strong, and others where u hear it really weak, rooms are full of blind spots and peeks, and they vary in location depending on the wavelength.
thats why when i set up my subs i always play every note and move the subs about until i can get it as flat as i can, but its not easy
so rant over, there is a difference between distortion, and a non flat frequency response
all the woods cut, driver hole cut, will begin to assemble tomorrow
i kinda stood the planks together in a box shape today with the speaker in to test, i found that there was no 20hz bass
then i push down on a small crack and i hear some, then i squeeze another corner and even more, then i sit on it, wow now were talking... then the top end rattles off, and air is flying out here there and everywhere, not a good idea, dam my impatiences, just wish i wasn't working all week,
so i defiantly need loads of strategic but streamlined bracing, i have a tube of no more nails sealant that i will run over every single edge imaginable.
anyway i am taking pics of the construction from start to finish, and will post up the final plan and input info, along with a nice slideshow of construction, and my review, this will be good for anyone looking to build a sub the lazy way (using someone else's hard work) but i dont mind, u guys helped me enough.....
i don't think the sound that isn't simulated in horn resp as flat, is necessary distorted, it just has peeks and dips, there is a big difference there, my sim only shows peeks of 5db, and room peeks and dips are alot bigger
do a test, play a note like 70hz or 100hz using a generator, walk around the room, there will be places u hear it really strong, and others where u hear it really weak, rooms are full of blind spots and peeks, and they vary in location depending on the wavelength.
thats why when i set up my subs i always play every note and move the subs about until i can get it as flat as i can, but its not easy
so rant over, there is a difference between distortion, and a non flat frequency response