Thank you Brian Steele.
I think that I must study HornResp. then BOXPLAN-THAM 4.4. is very hard for me to understand now, but I will keep trying to understand.
As a conclusion, here I can create a custom THAM? a big one or a small one? and I can make the perfect tuning to the box enclosure for my own speaker?
I see that Tham 12 and Tham 18 have the same SPL (because the THAM martinsson is tuned for best response in the area from 50 to 100 Hz).
Now, I want to make a THAM that get lower, from 43 or 45 Hz. For that I need a bigger box and a long horn ? true?
Do I need a 15" or 18" speaker for 43 Hz or a good 12" is enough?
I want the best SPL ever from 43 or 45Hz to 75Hz but I want the smallest enclosure possible. I believe that tham design put the bass just in front and another advantage is that multiple THAMs work together even at outdoor venue, so I don't need complicated end fire design if I use THAM? true?
to make it simple, I see that Danley use THmini 12" (48 Hz - 200 Hz - 3 dB in a 140liters enclosure with 700W obtain 129dB SPL) then a 15" TH115 (38 Hz - 200 Hz -3dB in a 420 liters box with 100W driver obtain 133dB SPL).
I want to buy B&C 12NW100. Same "engine" like 15NW100 and 18NW100, just the bigger cone and the Fs is not the same, but the BL factor and voice coil are the same. Thats why I want to use 12" in THAM design.
I want to build a 200 (ish) liters enclosure tuned for 43 to 75 Hz ... around 200 liters.
I dont see tham 12 yet. Maybe the original design is ok/enough low bass, maybe not. I cant test my sound system because now I am in the recovery period after a surgical operation, so I am not allowed to rise more than 5 kilos. I have two 18" BR classic.
my experiences say that 50 to 100 Hz is not low enough. I need 43 Hz @-3dB maybe 45Hz @-3dB and 43 @-6dB...is not the end of the world....I want a little bigger, and a little lower. maybe a THAM 15" is enough in real world. One guy say that THAM 18 is getting lower than a BR .... hard to say...very subjective...
I want a scalable LEGO-like system, for small venue, a single THAM, for big venues 6 THAMs in line in center...
Please, let's debate my ideas.
I think that I must study HornResp. then BOXPLAN-THAM 4.4. is very hard for me to understand now, but I will keep trying to understand.
As a conclusion, here I can create a custom THAM? a big one or a small one? and I can make the perfect tuning to the box enclosure for my own speaker?
I see that Tham 12 and Tham 18 have the same SPL (because the THAM martinsson is tuned for best response in the area from 50 to 100 Hz).
Now, I want to make a THAM that get lower, from 43 or 45 Hz. For that I need a bigger box and a long horn ? true?
Do I need a 15" or 18" speaker for 43 Hz or a good 12" is enough?
I want the best SPL ever from 43 or 45Hz to 75Hz but I want the smallest enclosure possible. I believe that tham design put the bass just in front and another advantage is that multiple THAMs work together even at outdoor venue, so I don't need complicated end fire design if I use THAM? true?
to make it simple, I see that Danley use THmini 12" (48 Hz - 200 Hz - 3 dB in a 140liters enclosure with 700W obtain 129dB SPL) then a 15" TH115 (38 Hz - 200 Hz -3dB in a 420 liters box with 100W driver obtain 133dB SPL).
I want to buy B&C 12NW100. Same "engine" like 15NW100 and 18NW100, just the bigger cone and the Fs is not the same, but the BL factor and voice coil are the same. Thats why I want to use 12" in THAM design.
I want to build a 200 (ish) liters enclosure tuned for 43 to 75 Hz ... around 200 liters.
I dont see tham 12 yet. Maybe the original design is ok/enough low bass, maybe not. I cant test my sound system because now I am in the recovery period after a surgical operation, so I am not allowed to rise more than 5 kilos. I have two 18" BR classic.
my experiences say that 50 to 100 Hz is not low enough. I need 43 Hz @-3dB maybe 45Hz @-3dB and 43 @-6dB...is not the end of the world....I want a little bigger, and a little lower. maybe a THAM 15" is enough in real world. One guy say that THAM 18 is getting lower than a BR .... hard to say...very subjective...
I want a scalable LEGO-like system, for small venue, a single THAM, for big venues 6 THAMs in line in center...
Please, let's debate my ideas.
Hi Cipisound,
I feel like I might offer some of my experiences with TH and the boxplan tools Brian has created.
I have built 4 TH now.
1) First I built the Martinssen TPAM10HTL
2) Then I built a pair of the 18hz tuned Snider LAB12 loaded with a variety of Alpine car audio drivers.
3) Finally, I recently built a 266 liter Boxplan MTH tuned to about 24hz. I call this my BP-MTH-266.
So my application is HT and music chasing max extension, not outdoor performances where you'd want max SPL in your chosen passband.
In trying to understand which of the Boxplans could get me the lowest tune for a given exterior size I tried each Boxplan fold with my target 266 liter box (110H, 45W, 65D) that I could accommodate at the back of my lounge. Effectively I was trying to find which TH fold was most efficient at packing in the longest path in pursuit of the lowest tune.
What I found is that the MTH was that fold - mind you a few more Boxplans have appeared since that time which I've not tried.
Regarding drivers, my current BP-MTH-266 (and all TH's I've built) seems incredibly sympathetic to a very wide range of drivers. To be precise I've modelled and measured three drivers:
a) Alpine SWS-15D4
b) Celestion AD15H; and
c) RCF LF15N451
Here's a chart of the three drivers in this enclosure:
The take away from this variety is that the box is in charge of the passband.
The drivers efficiency, Xmax and power handing will determine how loud you can go. The Alpine beats the Celestion because even tho it is considerably less efficient it has a ton of Xmax and gets a fair bit louder as a consequence. I've not had a chance to take the BP-MTH-266 with the RCF LF15N451 loaded outside so that I can belt on it to see how loud it can play before it starts making noises, but with 64mm Xlim I'm hoping it can take a heap.
Going back to the Martinssen TPAM, this design had some serious capacity for chest slam with just a mediocre 10". I wonder if this had something to do with the shape of the mouth? I would love to build some THAM and/or some of the other more music orientated TH's with the horn like mouth if this is the source of this slam capacity, I really like the physicality of the Martinsson TPAM.
Regarding the Boxplan .xls tools - these are by far the easiest build. The tools' graphic for the enclosure gives very precise path coordinates which makes cutting and laying out the horn path a breeze, it was a revelation for me how much easier Brian's tools make the build process.
I have really enjoyed designing, building and listening to my tapped horns. I highly recommend you learn HornResp - Brian's DIYSubwoofers steps you through how to model each kind of subwoofer alignment using HornResp on his site.
Then all you need to decide is the external dimensions of your enclosure, add this to your chosen Boxplan, choose a driver and load up its specs then import to HornResp to see your passband. Smaller box for a higher tune, larger box for a lower tune. Easy as!
Hope this helps. Enjoy.
I feel like I might offer some of my experiences with TH and the boxplan tools Brian has created.
I have built 4 TH now.
1) First I built the Martinssen TPAM10HTL
2) Then I built a pair of the 18hz tuned Snider LAB12 loaded with a variety of Alpine car audio drivers.
3) Finally, I recently built a 266 liter Boxplan MTH tuned to about 24hz. I call this my BP-MTH-266.
So my application is HT and music chasing max extension, not outdoor performances where you'd want max SPL in your chosen passband.
In trying to understand which of the Boxplans could get me the lowest tune for a given exterior size I tried each Boxplan fold with my target 266 liter box (110H, 45W, 65D) that I could accommodate at the back of my lounge. Effectively I was trying to find which TH fold was most efficient at packing in the longest path in pursuit of the lowest tune.
What I found is that the MTH was that fold - mind you a few more Boxplans have appeared since that time which I've not tried.
Regarding drivers, my current BP-MTH-266 (and all TH's I've built) seems incredibly sympathetic to a very wide range of drivers. To be precise I've modelled and measured three drivers:
a) Alpine SWS-15D4
b) Celestion AD15H; and
c) RCF LF15N451
Here's a chart of the three drivers in this enclosure:
The take away from this variety is that the box is in charge of the passband.
The drivers efficiency, Xmax and power handing will determine how loud you can go. The Alpine beats the Celestion because even tho it is considerably less efficient it has a ton of Xmax and gets a fair bit louder as a consequence. I've not had a chance to take the BP-MTH-266 with the RCF LF15N451 loaded outside so that I can belt on it to see how loud it can play before it starts making noises, but with 64mm Xlim I'm hoping it can take a heap.
Going back to the Martinssen TPAM, this design had some serious capacity for chest slam with just a mediocre 10". I wonder if this had something to do with the shape of the mouth? I would love to build some THAM and/or some of the other more music orientated TH's with the horn like mouth if this is the source of this slam capacity, I really like the physicality of the Martinsson TPAM.
Regarding the Boxplan .xls tools - these are by far the easiest build. The tools' graphic for the enclosure gives very precise path coordinates which makes cutting and laying out the horn path a breeze, it was a revelation for me how much easier Brian's tools make the build process.
I have really enjoyed designing, building and listening to my tapped horns. I highly recommend you learn HornResp - Brian's DIYSubwoofers steps you through how to model each kind of subwoofer alignment using HornResp on his site.
Then all you need to decide is the external dimensions of your enclosure, add this to your chosen Boxplan, choose a driver and load up its specs then import to HornResp to see your passband. Smaller box for a higher tune, larger box for a lower tune. Easy as!
Hope this helps. Enjoy.
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The purpose behind the BOXPLAN workbooks is to allow you to design a TH that meets your specific needs. Whether or not your custom TH turns out to be "perfect" is another matter
.Now, I want to make a THAM that get lower, from 43 or 45 Hz. For that I need a bigger box and a long horn ? true?
Efficiency at lower frequencies is a function of box size and tuning. If you want to maintain the same efficiency as the "official" THAM designs but get lower, box size is likely going to be larger. However, SPL capability is also a function of the driver that you use in the design, so you may be able to make up for a loss in efficiency by using a driver that provides higher SPL capability (greater Xmax and power-handling) than those used in the original THAM designs.
That depends on the SPL level that you're trying to achieve.
Vented boxes and MLTLs are probably the best choice at the moment for this, once you have enough power to drive them (and this higher power requirement does introduce its own issues). THs can achieve the same (or greater) SPLs, but require larger boxes.
Have a closer look at where those peak SPLs are being achieved - check the response curves for each. In any case, the Danley designs appear to be very good ones (I haven't heard one yet, but the engineering behind them seems to be sound), and I doubt you could go wrong with either.
The Xmax of that driver is basically identical to the Eminence Kappalite 3012LF that I'm using in my POC3.1 TH that's tuned to 39 Hz. The other parameters are a bit different though (Qes seems to be quite a bit lower). Going by Sd*Xmax however, I expect peak SPL capability is going to be similar to the Kappalite 3012LF in a ~40 Hz TH, which isn't a lot.
You should be able to fit a 15" driver in an enclosure that's that size (net) and still get down below 50 Hz, and you'll achieve higher SPL than if you use a 12" driver. For example, the 15SW100 driver in a 42 Hz TH folded into a ~185L box will get you to 130dB with 1.5kW, within the linear and power capabilities of the driver.
Brian I'm just starting to use the Excel sheets. I measured my driver with DATS and I have the impedance curve. How can I derive the semi-inductance values from the curve? I've look everywhere in the forum. Couldn't find it.
Just a few minor updates...
1. I've included the ability to model the use of either one or two drivers in some of the BOXPLAN workbooks (BOXPLAN-TL1, BOXPLAN-TL2 and BOXPLAN-MTL3). I aim to extend that ability to some of the other workbooks over the next few weeks, if the box layout suggests that more than one driver can be easily supported. Note that this isn't fully supported by Hornresp yet - the initial import of the Hornresp file does work, but if you subsequently change the number of drivers in the BOXPLAN workbook, do an export and then press F6 in Hornresp to quickly update the sim, it won't pick up the change in the number of drivers used. David says this should be addressed in the next version of Hornresp.
2. I've included a feature that I call "A good start...?" with some of the workbooks (just BOXPLAN-TL1 and BOXPLAN-TL2 for now). Selecting that option gives a "starter" design, based on the driver's t/s parameters. Note I said STARTER design. You should examine that design in Hornresp and adjust it accordingly to get the best results.
1. I've included the ability to model the use of either one or two drivers in some of the BOXPLAN workbooks (BOXPLAN-TL1, BOXPLAN-TL2 and BOXPLAN-MTL3). I aim to extend that ability to some of the other workbooks over the next few weeks, if the box layout suggests that more than one driver can be easily supported. Note that this isn't fully supported by Hornresp yet - the initial import of the Hornresp file does work, but if you subsequently change the number of drivers in the BOXPLAN workbook, do an export and then press F6 in Hornresp to quickly update the sim, it won't pick up the change in the number of drivers used. David says this should be addressed in the next version of Hornresp.
2. I've included a feature that I call "A good start...?" with some of the workbooks (just BOXPLAN-TL1 and BOXPLAN-TL2 for now). Selecting that option gives a "starter" design, based on the driver's t/s parameters. Note I said STARTER design. You should examine that design in Hornresp and adjust it accordingly to get the best results.
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Hi Brian, thanks for this. I would be very appreciative if you might add the dual driver option to the MTH and MTHALT workbooks too please. I have a nice old pair of alpine series one typre R's in my shed that I hope to model as a dual.
Would also be awesome to have the MTHALT upgraded to have the optimise function added if possible. The MTH lends itself well to the flexibility of the two mouth terminations to accommodate alternative room orientations.
Cheers.
Would also be awesome to have the MTHALT upgraded to have the optimise function added if possible. The MTH lends itself well to the flexibility of the two mouth terminations to accommodate alternative room orientations.
Cheers.