Don Snyder said:
I built this 20Hz tapped horn subwoofer. It was banned from the house by She whom must be obeyed. For some reason the wife got upset when one of her antique english tea pots rattled off its shelf and smashed into pieces. Anyway, since the Tang Band W8-740C woofers are 4 ohms I decided to wire them in series and give my amplifier an easier time. Also, I had to add a 2.5mH inductor to flatten the response some. The woofers are arranged in a distortion reducing push-pull configuration. One woofer’s magnet is inside the compression chamber, and the other is outside. Looking at picture #2, you can see that the woofer that would be mounted on the left side would have its magnet outside. I really like how this type of push-pull can make the Dumax behavior much more linear. I think its coolest trick is how low frequency SPL waves can massage your pants leg. The amount of output from this thing was ridiculous and lead to it being banned from the house. Every once in a while when the wife is gone, I carry it back into the house and play it.
Thanks for the kind words guys! I may have gone a little overboard with the bracing, but I was having fun playing with my new tools. One thing that is nice though is that the sub is silent (no rattles or other mechanical noises when producing 25-15hz signals. In contrast my VMPS subs made a fair amount of noise doing these test. However I never noticed anything when playing movies/music.
I just finished running some frequency sweeps in RoomEQwizard and even though my sub is crossed at 80Hz, 100hz from the sub is just as loud as the bandpass signal. In other words, that 100hz peak that HR shows is real. It was my intention to use a Behringer DSP1124P Feedback Destroyer to kill that peak and eq the sub a little. I know other people have reported that HR exaggerates the peaks, so I though I should mention it. I guess it could be a room mode though.
This sub still continues to impress. I watched LOTR ROTK the other night and compared to the VMPS, it's just so much more accurate. The TH seems like it's producing less boom and overhang. This sub has impact! Hits are very solid and weighty, but since there's less boom, the sub kind of sound quieter if that makes sense; less overall energy, but more information.
Anyway, here are the HR FR plots in 1/4 space (pi). My rough sketch build plan is based on a baffle/external wall height of 450mm.
Please note that I'm very new to DIY audio and while I'm happy with the overall result in my room, I'm sure there's lots of room for improvement. Basically I had some very specific requirements for size and frequency response, otherwise I would have just copied someone else's design
. I've been following this thread for about a year now, so thanks to all who posted/helped and also thanks to Mr Mc Beans fantastic software. And last, but not least I think we all can appreciate a wife that'll tolerate such an absurd room to speaker ratio! So thanks Mrs Steve71! 
I just finished running some frequency sweeps in RoomEQwizard and even though my sub is crossed at 80Hz, 100hz from the sub is just as loud as the bandpass signal. In other words, that 100hz peak that HR shows is real. It was my intention to use a Behringer DSP1124P Feedback Destroyer to kill that peak and eq the sub a little. I know other people have reported that HR exaggerates the peaks, so I though I should mention it. I guess it could be a room mode though.
This sub still continues to impress. I watched LOTR ROTK the other night and compared to the VMPS, it's just so much more accurate. The TH seems like it's producing less boom and overhang. This sub has impact! Hits are very solid and weighty, but since there's less boom, the sub kind of sound quieter if that makes sense; less overall energy, but more information.
Anyway, here are the HR FR plots in 1/4 space (pi). My rough sketch build plan is based on a baffle/external wall height of 450mm.
Please note that I'm very new to DIY audio and while I'm happy with the overall result in my room, I'm sure there's lots of room for improvement. Basically I had some very specific requirements for size and frequency response, otherwise I would have just copied someone else's design
. I've been following this thread for about a year now, so thanks to all who posted/helped and also thanks to Mr Mc Beans fantastic software. And last, but not least I think we all can appreciate a wife that'll tolerate such an absurd room to speaker ratio! So thanks Mrs Steve71! Attachments
Here is the rough build plan.. sorry Brett, this wasn't really meant to be understood by anyone but me.. and even then only for a brief period. D
If you have any questions, just let me know. Obviously this build plan doesn't take into account the internal baffle thickness. And as I said before the baffle/wall height is 450mm.
If you have any questions, just let me know. Obviously this build plan doesn't take into account the internal baffle thickness. And as I said before the baffle/wall height is 450mm.
Attachments
rcavictim said:
The overall dimensions are roughly 17" deep X 16" wide X 6' tall. Of course if you want to use a different woofer, you'll have to redesign for the T/S parameters of that woofer. Unless you are DJing outside gigs, I really don't know what you would do with the output of a dual 12" version of my tapped horn. The dual 8" version is already too much for home use.
serenechaos said:
No, you can't run this one up past 60Hz. The Definimax 4012HO is a better tapped horn for reaching up to 80Hz - 100Hz. I find that with low sensitivity speakers like the Tang Band, you will have a restricted bandwidth. However, with higher sensitivity speakers like the 4012HO, you end up with more bandwidth before things get ugly in the higher frequencies.
Hi guys,
after having studied this thread, it's amazing to me why the tapped horns are not more popular in the DIY corner.
I have found an older CarHifi sub in my cellar. Fortunately I also had the chance to measure the TSP.
Thiele-Small parameters:
Fs = 19.33 Hz
Re = 3.25 ohms[dc]
Le = 13421.90 uH
L2 = 11460.35 uH
R2 = 8.16 ohms
Qt = 0.43
Qes = 0.45
Qms = 8.40
Mms = 96.67 grams
Rms = 1.397754 kg/s
Cms = 0.000702 m/N
Vas = 118.21 liters
Sd= 346.36 cm^2
Bl = 9.162766 Tm
ETA = 0.18 %
Lp(2.83V/1m) = 88.58 dB
The living room in our new built house has a longitude of 8,9m. If calculated correctly this shoudl correspond with a resonance of ~38Hz.
Would this woofer be an appropriate candidate for a TH sub?
How should I consider the room modes for designing such a sub?
Regards
Thorsten
after having studied this thread, it's amazing to me why the tapped horns are not more popular in the DIY corner.
I have found an older CarHifi sub in my cellar. Fortunately I also had the chance to measure the TSP.
Thiele-Small parameters:
Fs = 19.33 Hz
Re = 3.25 ohms[dc]
Le = 13421.90 uH
L2 = 11460.35 uH
R2 = 8.16 ohms
Qt = 0.43
Qes = 0.45
Qms = 8.40
Mms = 96.67 grams
Rms = 1.397754 kg/s
Cms = 0.000702 m/N
Vas = 118.21 liters
Sd= 346.36 cm^2
Bl = 9.162766 Tm
ETA = 0.18 %
Lp(2.83V/1m) = 88.58 dB
The living room in our new built house has a longitude of 8,9m. If calculated correctly this shoudl correspond with a resonance of ~38Hz.
Would this woofer be an appropriate candidate for a TH sub?
How should I consider the room modes for designing such a sub?
Regards
Thorsten
It's OK for a big one (~1025 L net) tuned low (~9.66 Hz), so usable low distortion excursion combined with the room gain will set power handling below ~30 Hz.
Ideally you would map the room's modes and make the sub's response the inverse of it, i.e. where there's a room peak/null the sub will have a matching gain BW null/peak. By design, no trivial pursuit, though I imagine using a sealed cab with a 'close enough' Qtc to mirror the room's gain curve and a parametric EQ ahead of the sub's amp is the easy way.
BTW, what's the brand/model # for my records?
GM
Ideally you would map the room's modes and make the sub's response the inverse of it, i.e. where there's a room peak/null the sub will have a matching gain BW null/peak. By design, no trivial pursuit, though I imagine using a sealed cab with a 'close enough' Qtc to mirror the room's gain curve and a parametric EQ ahead of the sub's amp is the easy way.
BTW, what's the brand/model # for my records?
GM
Attachments
It's a discontinued model, a Cerwin Vega 104.
1m3 is a huuuge monster but definetely no-go. I was actually looking for a sub covering the range up to ~100Hz. As a mains I'm looking for some nice fullrange or PA-coax system.
To keep vibrations and distortions down low it might perhaps be more reasonable to use two moderate 6,5" in push-pull setup per side. Any recommends for such small (mid)woofers?
The woofer boxes shouldn't be higher than 80cm, cause they will be the stands for the coaxes/FR systems. So it's gonna be a folded horn.
Can you explain to a rookie like me what's the theoretical background to tune the casing to 1/2 of Fs?
1m3 is a huuuge monster but definetely no-go. I was actually looking for a sub covering the range up to ~100Hz. As a mains I'm looking for some nice fullrange or PA-coax system.
To keep vibrations and distortions down low it might perhaps be more reasonable to use two moderate 6,5" in push-pull setup per side. Any recommends for such small (mid)woofers?
The woofer boxes shouldn't be higher than 80cm, cause they will be the stands for the coaxes/FR systems. So it's gonna be a folded horn.
Can you explain to a rookie like me what's the theoretical background to tune the casing to 1/2 of Fs?
Is there a consensus at this point on a design for a ~20 hz design that has been tried, that will work with available drivers?
I was looking at the folded Eminence Lab 12 design by Don Snyder, and saw that tupaki built one with a different driver, and seemed pleased with the result. When I went looking for the Lab 12 I found the Lab 12 Generation 2. Is that the driver that was used for the design? Is it close enough to work?
Regarding this design, I noticed in one post that Don said that he modified it slightly in order to eliminate the need for an access panel. Did he post the unmodified version?
Is this also the design that Chris8sirhC built out of wafer board?
I also found interesting JLH's dual 8" Tang Band design. In it he used a pair of W8-740C drivers. The closest I found was the W8-740P are these similar enough to be used without redesigning?
I need to fill a 16' x 25' x 9' room with bass for home theater, would prefer the simplicity of 1 sub, and have a wife that I would like to keep (loves bass, but has a more genteel aesthetic). Given these parameters, where in these 2,000 + posts can I find a design that has been built with good results?
Paul
I was looking at the folded Eminence Lab 12 design by Don Snyder, and saw that tupaki built one with a different driver, and seemed pleased with the result. When I went looking for the Lab 12 I found the Lab 12 Generation 2. Is that the driver that was used for the design? Is it close enough to work?
Regarding this design, I noticed in one post that Don said that he modified it slightly in order to eliminate the need for an access panel. Did he post the unmodified version?
Is this also the design that Chris8sirhC built out of wafer board?
I also found interesting JLH's dual 8" Tang Band design. In it he used a pair of W8-740C drivers. The closest I found was the W8-740P are these similar enough to be used without redesigning?
I need to fill a 16' x 25' x 9' room with bass for home theater, would prefer the simplicity of 1 sub, and have a wife that I would like to keep (loves bass, but has a more genteel aesthetic). Given these parameters, where in these 2,000 + posts can I find a design that has been built with good results?
Paul
I think all lab12 designs here use the newest driver generation, at least i did that. The lab12 sub will be big, you can sacrifice output to get a smaller volume by using a smaller driver. Preferable are 2 or 4 subs, for flat room response and the chance to hide them, as each one will be smaller than one big sub.
aceinc said:
I believe that the ending letter of the Tang Band models denotes batch numbers. While there might be slight changes to some of the T/S parameters, for all practical purposes the C and P are the same woofer. I compared the data sheets and everything is the same. Also, you know there is nothing wrong with designing your own TH.
Rgs, JLH
I have a few unused TB W6's, looking at JLH's PP cool design pushed me to fire up hornresp and this is what I came up with so far. My goal is to mate it to my 80hz horn.
Just wondering if you guys could critique it or check if I messed up somewhere. One thing I was not sure of is the TS specs, if anything gets doubled or halved in a PP arrangement.
SPL response is not bad for a $29 driver.
Just wondering if you guys could critique it or check if I messed up somewhere. One thing I was not sure of is the TS specs, if anything gets doubled or halved in a PP arrangement.
SPL response is not bad for a $29 driver.
Attachments
JLH, I have looked at using some Sony Xplod XS-L1036's that I have laying around not being used, and some Titanic 10's that are in sealed enclosures, but lack the confidence in my skills at using HornResp to come up with a successful design.
I played around with the Hornresp and seem to have an OK design at about 21' and 4.34 cu ft (if my metric conversion are correct). This is assuming I know what I am looking at.
It may be unbuildable and it has rather nasty peaks above 70 hz.
For fun I included my current iteration of the Titanic 10" Hornresp. I am using 2.0 x Pi in order to get a realistic guesstimate of in room response. Since this is a 4 ohm driver, what should I use for Eg to get a 1 watt approximation? The Driver TS specs come from the PE Dumax report.
Once I get past the fun of Hornresp, then comes the actual design of the box, as far as I know there are no programs to design a tapped horn with folds etc. This means pen and paper. Now I need to build it. It seems to me that I have a bunch of places where I can make mistakes along the way which may compound each other, yielding a rather large, heavy, white elephant.
I guess what I am saying is I would like to try and design and build this from scratch, but feel the chances for failure, or worse, mediocrity are great.
Paul
I played around with the Hornresp and seem to have an OK design at about 21' and 4.34 cu ft (if my metric conversion are correct). This is assuming I know what I am looking at.
It may be unbuildable and it has rather nasty peaks above 70 hz.
For fun I included my current iteration of the Titanic 10" Hornresp. I am using 2.0 x Pi in order to get a realistic guesstimate of in room response. Since this is a 4 ohm driver, what should I use for Eg to get a 1 watt approximation? The Driver TS specs come from the PE Dumax report.
Once I get past the fun of Hornresp, then comes the actual design of the box, as far as I know there are no programs to design a tapped horn with folds etc. This means pen and paper. Now I need to build it. It seems to me that I have a bunch of places where I can make mistakes along the way which may compound each other, yielding a rather large, heavy, white elephant.
I guess what I am saying is I would like to try and design and build this from scratch, but feel the chances for failure, or worse, mediocrity are great.
Paul
