Guys, if you really considering going that low with a TH don't forget to look at 21" size drivers. They often fit in the same TH cabs but have advantages over the 18’s, better physical handling, better Xmax/Xlim, much lower power compression in low freq and higher SPL at low freq…
For instance load your TH cabs (the 400 liter one from the few first posts) with an 18Sound 21NLW9000C and you can feed it at least with double the power over an 18inch. You will gain at least 3dB but in reality more since HornResp doesn't 'see' everything...
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Hi epa,
I don't seem to remember cheap being one of the criteria of the iron law.
How about the Pyle PDW21250 (at least it's affordable):
Buy Pyle PDW21250 21" performance optimized high power subwoofer for $169.95
http://www.parts-express.com/pe/sho...9gtype=search&9gkw=pdw21250&9gad=6856334113.1
Regards,
I don't seem to remember cheap being one of the criteria of the iron law.
How about the Pyle PDW21250 (at least it's affordable):Buy Pyle PDW21250 21" performance optimized high power subwoofer for $169.95
http://www.parts-express.com/pe/sho...9gtype=search&9gkw=pdw21250&9gad=6856334113.1
Regards,
I know Epa, these are expensive but:
1.) Can handle the same SPL with 2cabs instead of 4cabs (so what is expensive?)
2.) Lower pwr compression
3.) Better physical handeling especially at the lowest octave
4.) Much higher crest factor so damage will be more a case of the amp than the driver!
Oliver,
Going with the DSL TH-118 (loaded with a B&C 18SW115-4) as a benchmark, it is 101 dB one watt one meter at 30 Hz.
Assuming the driver would stay under Xmax at 4000 watts, that would put the 30 Hz peak output for a single at 127 dB.
Add 12 dB for four, 139 dB at 30 Hz with 16,000 watts.
My meat computer says they will flap at less than half that power at 30Hz (below the driver’s Fs), I think 136 dB might just happen, but would still exceed Xmax.
Ordered a pair of B&C 18SW115-4 from Pro Sound Service yesterday, shipped this morning.
My build will probably be 26.5” by 22.5” x 45” tall cabinets, slightly more volume than the TH-118.
I’m very curious what the excursion looks like, just dragged in the GF’s Dell from cold storage, when it warms up will download Hornresp and start learning.
Have you done any sims of this driver in a tapped horn?
Art
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Huge disparities between Magnatar's and the manufacture specs, but as they rate it 45-1.7Khz, and it only has 9 mm Xmax, not a contender for big 30 Hz action.
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Thanks.
I'll have to look at that more closely.
One thing that concerns me about Hornresp is it shows Tapped Horn LF corner dropping in multiples, while Danley has stated, and shown plots where they do not.
Regular horns with "too small" mouths do drop the LF corner in multiples.
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actualy your driver mathematical x-max is 14mm (10% distortion point)
with 2 cabs you reach 135 db @32 hz ,witch is verry nice,but you wil get near 140db with the 4*bms.
i moddeled it about a litle more than half size of olivers model.
its about 3to 4 db less with 4 cabs.
pic any 2 off small,loud or low
Martin, Like Soho says it really depends on the driver. A modern driver (with suitable horn specs) with an Xlim that is at least 2x its Xmax is often build to last (although don't use this as a rule). But you have to use a driver in practice to see how the driver will hold up in a horn. As Epa seems to be worried about the Xmax of the 18Sound 21" I prefer to look at the driver's Xlim and how the cone, spider and basket are build up (and how it handles heat under heavy loading). In my experience good engineered drivers (and that’s why they cost a lot more) will stand the physical pressure from horn loadings when they need to exceed their Xmax… That’s why I’m not worried to load an 18Sound 21” (Xlim 35mm one way) in a TH with a bridged labgruppen FP6000Q (3000W/4Ohm - Bridgedchan).
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what drivers are in the titan 48,maybey we can model something with that.
15 cu. ft how many liters is that?
i think 140 wil be a challange @30 hz with 4.
ill keep digging
edit/ 425 liters
The Titan 48 uses the Eminence 3015LF - same as in the Furysub, jbell's single sheet SS15 and big box. The 3015LF likes a BIG box to get low, however.
have you seen this site?
email them to see for howmuch you can get 4x bms 850 v2
i dont see how you can get close with any other driver.
better spend a litle more,then go al the effort and go hmmmz
remember xco1 600 ltr cab got to 140 @30 hz with 4.
why not us a trailer behind your truck,
thats how i move my 4 650 ltr horns.
THAAAAT's where I saw them for $350.. I looked again and saw a VERY similar looking price sheet and they were $100 more.. Thanks for the link. You have put the 18N850 back in the runnings!
I'll have to check further on this. At first look, one cab appears to cost more than two 18" cabs worth. And needs a whole lot of amp power.. Further checking soon
Aaaand you're still at it - right after the Furysub build! Glad to hear!
There are some models w/the 18SW115 in wood1y's post at the bottom of http://www.diyaudio.com/forums/subwoofers/170749-15-tapped-horn-rcf-7.html page. I believe I used B&C's posted xmax values, so spl should be 'slightly' lower if using the calculated xmax (~2mm less). Keep us updated with your progress!
Yes, looks quite good!
That still is a very nice design, btw. Kudos.
i was thinkin about that 2 jason.
i tought 2:1 was max for 18",so i figured for 21"it would be even less.
i did some modeling with the pyle driver,its usable and does move air.Hi epa,
I don't seem to remember cheap being one of the criteria of the iron law.
Buy Pyle PDW21250 21" performance optimized high power subwoofer for $169.95
Pyle Pro PDW21250 21" High Power Subwoofer | Parts-Express.com
Regards,
few concerns about that diver are,we dont know all the ts parameters and i dont know how they handle real pa work (allu vc former?).
that said ,from experience i'd go with a pro driver,its worth the extra money,especialy over time.
we don't even know how the x-max is caculated,it might as wel be 9mm peak peak,or 9mm x-damage
justin i moddeled somethig for the 3015lf a while ago,and it sims quite good actualy.its just not so loud.The Titan 48 uses the Eminence 3015LF - same as in the Furysub, jbell's single sheet SS15 and big box. The 3015LF likes a BIG box to get low, however.
THAAAAT's where I saw them for $350.. I looked again and saw a VERY similar looking price sheet and they were $100 more.. Thanks for the link. You have put the 18N850 back in the runnings!
but if you have already four of them you could buy 4 more.
with 8 cabs you could do some damage.
with the bms driver you need 4*600 ltr cabs each fed with 900 watts,to get 140 down to 30hz
if you want smaller cabs,you have to set your goals a bit lower.
any thoughts about that trailer idear?
for the bms,just email that site,simple. and then you know what they cost.make sure they sell the v2 version
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