I am seeing XMAX being hit at 126db at around 45 hz, and maximum theoretical flat response is there at 126db 35hz to 100hz at about 700 watts. That's disregarding compression, though given the low power it's not likely going to be much of an issue.
But you should expect less as there is more at play to consider, such as what epa noted above.
120 db should be attainable in 2Pi space but the eq needed to get it close to flat would likely add coloration.
I think the QTS is still too high for a TH.
Last edited:
Thank for you comment. I know that TH-18 not fit to all driver but now I'am looking for driver that resonable to use in this TH-18 (may be not perfect match). Now I have two choice to build subwoofer which way are better .
1.TH-18 with P audio some model such as C18650el , Fl18ELF ,2241,2242 now still not sure which one is the best for this TH-18
2241
http://www.paudiothailand.com/pdf/products/P180-2241.pdf
2242
http://www.paudiothailand.com/pdf/products/P180-22423.pdf
2.Go for SS15 with Eminence 3015lf or 4015lf
I concern only Flat and low respond. Size and weight not concern.
First time I decide to go TH-18 but now not sure any suggest.
Regards.
1.TH-18 with P audio some model such as C18650el , Fl18ELF ,2241,2242 now still not sure which one is the best for this TH-18
2241
http://www.paudiothailand.com/pdf/products/P180-2241.pdf
2242
http://www.paudiothailand.com/pdf/products/P180-22423.pdf
2.Go for SS15 with Eminence 3015lf or 4015lf
I concern only Flat and low respond. Size and weight not concern.
First time I decide to go TH-18 but now not sure any suggest.
Regards.
one more question for How to pick driver to use i the TH-18 Which parameter that I should concern alot?
first time I looking for driver that parameter that close to 18sound 18lw2400
such as
18sound 18lw2400 P-audio FL18elf
FS=35Hz FS=36Hz
Xmax =9.5 Xmax =8.0
Qms =7.2 QMS=7.67
Qes =0.32 Qes=0.41
Qts =0.31 Qts=0.39
My conclusion after looking into this for the last month is that while there are quite a few options for drivers that will withstand the forces inside a tapped horn, the two that are going to give decent output are the B&C 18SW115 and the 18 Sound 18LW2400 (or 2500 when it is released later in the year, much better spec'd)
Those drivers use newer technology and will suffer less power compression at high volume.
I think choosing something else will either disappoint with its poor performance, or in some cases be destroyed in a short time.
Specifically the QTS needs to be low, around 0.3. A less stiff cone is going to flex (or crumble!) under the strain.
Driver displacement goes through the roof as you get lower, so longer XMAX is required for deeper extension and higher SPL in a tapped horn, and a high pass filter is essential to protect the driver from damage.
Those drivers use newer technology and will suffer less power compression at high volume.
I think choosing something else will either disappoint with its poor performance, or in some cases be destroyed in a short time.
Specifically the QTS needs to be low, around 0.3. A less stiff cone is going to flex (or crumble!) under the strain.
Driver displacement goes through the roof as you get lower, so longer XMAX is required for deeper extension and higher SPL in a tapped horn, and a high pass filter is essential to protect the driver from damage.
Last edited:
Um dont forget the 9600/9601... the drivers that danley used originally in the TH18. I'd take that over the 2400 any day.
Optimal High Pass
Gents,
While playing around with measurments and settings on my DSP I found that I get more output in the low end of the pass band if I select Butterworth instead of Linkwitz-Riley.
I wasn't paying attention to the fact that Q is higher on Butterworth? and the level at crossover is different between the two of them.
There is a lot of output close to the 35 hz area, but it gets critical quite fast as you go below the loading from the horn, so Isn't it all about having the steepest slope possible when talking sub high pass?
Can anyone share - or recommend High Pass settings?
I am using B&C18SW100 and cone correction from Djim.
Greatings, Andy
Gents,
While playing around with measurments and settings on my DSP I found that I get more output in the low end of the pass band if I select Butterworth instead of Linkwitz-Riley.
I wasn't paying attention to the fact that Q is higher on Butterworth? and the level at crossover is different between the two of them.
There is a lot of output close to the 35 hz area, but it gets critical quite fast as you go below the loading from the horn, so Isn't it all about having the steepest slope possible when talking sub high pass?
Can anyone share - or recommend High Pass settings?
I am using B&C18SW100 and cone correction from Djim.
Greatings, Andy
Ya I have been finding that out lately. I like the 9601 as my FAV 18 but its the same price as the BC 21". Well roughly. And that is my favorite 21. And after seeing that price I had an excuse to build the Othorn.
And I will also order some new 18LW2500's smaller power handling same excursion as the 9601. The 2500 cost about half the price for the 9601. Which is good enough for me.