im thinking on dumping the 18" woofer for either double 12" or double 15".
12" or 15" pro audio wont be much lower than
50 to 40 Hz free air.
So reflex about the same.
18" wont really go much deeper.
But free air is at least 30 Hz
So bass wont be much different.
But at least the reflex wont be right were
actual bass is. 40 to 50 Hz
Transient be better not having a reflex
at 50 Hz more like 30 Hz
only real reason to care for pro audio 18"
1st order very minimal control over filter
transfer function to get something to sum reasonable
One capacitor makes life completely change.
Even first order would need impedance comp.
a cap is gonna appear either way.
Might as well use it for a more useful filter.
I'm using 18FH500 in the open baffle with 2nd order XO ~600 and am quite happy with them, great drivers.
Slightly off topic, but why are "real" woofers so rare in pro audio? When I model most of the pro audio drivers, I get a response that starts to roll off at 50 - 60 Hz. A big woofer with an Fs of 42 Hz and a Qts of 0.29 is just not going to get much lower than 50 hz. Loud, yes. Deep? eh, not so much... Not really a woofer if you think about it... more of a huge mid-bass driver.
If one wants a vented box response that is flat to 40 Hz, and useable down to 30 Hz, we need a woofer with an Fs below 30 Hz. I would like to have some more options for a woofer like this in the 15" - 18" size...
If one wants a vented box response that is flat to 40 Hz, and useable down to 30 Hz, we need a woofer with an Fs below 30 Hz. I would like to have some more options for a woofer like this in the 15" - 18" size...
Hi Jim, my limited experience with live amplified sound is flat to 40Hz is often the goal, but more and more that seems to be moving towards 30Hz.
Probably because rigs are often being used for live -DJ's etc.
So there hasn't been a need for the very lows home-audio needs (or perhaps more correctly, thinks it's getting haha)
That said, very large scale events like Coachella (check out Dave Rat's super subs) or events that would use something like Meyersounds 1100VLFC subs, are in a whole 'nuther league, going waay low.
Such type events are reputed to get prodigious output, very low.
Ok, apart from lacking a need to go way low for ordinary prosound live-sound work,
there's also the inescapable fact to maintain equal SPL for every octave decrease in frequency, 4X the displacement is needed.
So even if a driver is designed with a very low fs, it doesn't change how many of them, how many boxes will be needed, to achieve lower extension and maintain linear SPL.
For example, say I have a sub that is flat to 40Hz then rolls off. But let's say I want it to be flat to 20Hz.
I can boost the low end, but xmaz puts a quick limit on the available 20Hz SPL. Which lowers the systems' linear out put down to that 20Hz SPL level.
Solution? .... make it 4 of the same sub, to achieve the 4X displacement needed, and EQ down the excess response above 20Hz.
(another reason you don't see 20Hz often in live sound ...4X times to gain an octave down low gets $$$$)
Let's say I have another sub with the same sized driver with the same xmax, that already achieves 20Hz. A real woofer by home audio standard.
Ok, to get the same 20Hz SPL as the bank of 4 subs above, well ....it takes 4 of these "real woofer" boxes too.
Nothing gained...and durability very probably lost with a driver that qualifies as a real woofer..
Morals of the story imo.
Any driver can 'reach as low as you want'.....issue is at what volume.
And ye ole 'no replacement for displacement' (of course excepting true efficiency gains from hon loading etc)
Because most are woofers/midwoofers, meant to be used with dedicated, high xmax sub arrays in PA applications.
The BMS 18N862 is one of the few exceptions but they need some serious power to perform.
Also because all pro audio today is done with active crossovers and DSP, using low impedance Class D amps, low Q drivers forced below FS with the corresponding enormous power handling capabilities and stiff suspensions to make them survive the abuse that they get put through.
Those design traits means FS goes up, and no one really cares about it, as it is cheaper and easier to use a few KW of "cheap" class D amps with SMPS to force the response to what you need, only caring about weight,power handling and xmax. It also saves weight which is essential if you move large systems around, also large part of the popularity of cheap neo magnets from China - Weight and space savings.
there is very few manufacturers that makes products in between the "high sensitivity" PA products.
And the usual 85 db Hifi designs.
As that is 95% of the market, so it naturally is so.
Also modern design demands tiny boxes, which again makes low VAs/high FS etc a natural product of that.
The BMS 18N862 is one of the few exceptions but they need some serious power to perform.
Also because all pro audio today is done with active crossovers and DSP, using low impedance Class D amps, low Q drivers forced below FS with the corresponding enormous power handling capabilities and stiff suspensions to make them survive the abuse that they get put through.
Those design traits means FS goes up, and no one really cares about it, as it is cheaper and easier to use a few KW of "cheap" class D amps with SMPS to force the response to what you need, only caring about weight,power handling and xmax. It also saves weight which is essential if you move large systems around, also large part of the popularity of cheap neo magnets from China - Weight and space savings.
there is very few manufacturers that makes products in between the "high sensitivity" PA products.
And the usual 85 db Hifi designs.
As that is 95% of the market, so it naturally is so.
Also modern design demands tiny boxes, which again makes low VAs/high FS etc a natural product of that.
If you want usable range to 30 Hz, then choose a woofer with Fs = 30 Hz, put into a vented box tuned to Fs, and if it's not flat in the listening room, then give to it some EQ.
Examples:
Faital Pro 18FH500 4 or 8 Ohm, 18XL1800, 18XL2000
RCF LF18X451, LF18X401, L18P400
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JBL used to have a pro pa woofer based on w15gti
Mc cauley was famous for 6174 18" woofer.
But I guess now with infinite power and speakers it is possible to achieve high output at loooow frequency.
People often think this is what hammers you but it is not really happening here.
Anyway for home use I think something with high excursion high power would be better to help your 15" bass speaker.
Something like that
https://www.daytonaudio.com/product/1123/um15-22-15-ultimax-dvc-subwoofer-2-ohm-per-coil
Or
https://www.parts-express.com/Dayto...-Series-HO-Subwoofer-4-Ohm-295-469?quantity=1
Peerless also offers a 15" monster
Mc cauley was famous for 6174 18" woofer.
But I guess now with infinite power and speakers it is possible to achieve high output at loooow frequency.
People often think this is what hammers you but it is not really happening here.
Anyway for home use I think something with high excursion high power would be better to help your 15" bass speaker.
Something like that
https://www.daytonaudio.com/product/1123/um15-22-15-ultimax-dvc-subwoofer-2-ohm-per-coil
Or
https://www.parts-express.com/Dayto...-Series-HO-Subwoofer-4-Ohm-295-469?quantity=1
Peerless also offers a 15" monster
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Also, I can't decide which amp would be best value for money, hypex, crown xls, xti, thomann...., Yamaha px5/7....
The styles that require lower response (like a lot of less mainstream electronic music, including modern electronic (UK Stepper) dub) use cabinets that drive them lower, going from backloaded scoop horns over tapped horn and transflex systems. Those are mostly custom made for a "soundsystem" that is dedicated to a dj crew altough some (like Function One, Void and Danley Labs) also make them on a larger commercial scale. But it's still a niche where custom build systems rule largely. Tradtional big brand P.A. equipment can't play that music like it should most think (which is largely true). Those custom diy designs are also largely kept in the scene and you need to know the right persons to get them (or at least the good designs). A lot of these alignment are made to make a woofer go lower than FS by quarter wave tech (horn or Tl or hyrbids like tapped horn and transflex) so a woofer that only goes to 40Hz get's lower in those designs.
It started with the 1970's jamaican and UK reggae soundsystems, and in the early days it was certainly not very advanced or good sound quality, but these days these crews can compete with much of the bigger brands and start their own brands that sell a lot. Long time it was the same with amps and crossovers, but with modern class D and dsp they started to use more mainstream amps (Powersoft mainly). Mostec (for electronics), QSS, Mogale, Stakx, Jah Tubby's (altough their systems are getting outdated), F1, Void ... are high rated in those scenes and mainstream brands (except a few like old Crest amps or Turbosound horn speakers) are seen as useless. The big brands neglected a part of the market and so left a lot of opportunities for others. And a big part of that is the woofers, that don't go low enough.
It started with the 1970's jamaican and UK reggae soundsystems, and in the early days it was certainly not very advanced or good sound quality, but these days these crews can compete with much of the bigger brands and start their own brands that sell a lot. Long time it was the same with amps and crossovers, but with modern class D and dsp they started to use more mainstream amps (Powersoft mainly). Mostec (for electronics), QSS, Mogale, Stakx, Jah Tubby's (altough their systems are getting outdated), F1, Void ... are high rated in those scenes and mainstream brands (except a few like old Crest amps or Turbosound horn speakers) are seen as useless. The big brands neglected a part of the market and so left a lot of opportunities for others. And a big part of that is the woofers, that don't go low enough.
Thanks for all the thoughtful responses. I realize that live sound reinforcement is a different world, and I expected the solutions to deep bass to be unique to that realm... And very different from what might be done in a residential situation.
I am curious what is done in studios, for recording, mixing, and mastering? What bass drivers are used, and how much bass extension is needed? Are the requirements different based on music genre? Do movie/TV sound tracks have different requirements?
j.
I am curious what is done in studios, for recording, mixing, and mastering? What bass drivers are used, and how much bass extension is needed? Are the requirements different based on music genre? Do movie/TV sound tracks have different requirements?
j.
You can always try these ones out, the FS is certainly low enough, +/-15 mm is enough with that cone area. Then need a monster amp to drive thr heavy carbon fiber cones ofc.
The AD502 is the driver that sits in the Ascendo SMSG50 sub, (remove the logos and viola), they look absolutely identical from cone to frame and everything between, same voice coil dia, FS, and sensitivity/spl. That one retails for 90 000$, you can buy quite a few of those "custom made drivers" from China, for that price.🤣
Actually reasonably priced products, with decent performance, good inductance control, developed/tested with Klippel etc.some of them even exhibit nice and well behaved response curves too.
The AD502 is the driver that sits in the Ascendo SMSG50 sub, (remove the logos and viola), they look absolutely identical from cone to frame and everything between, same voice coil dia, FS, and sensitivity/spl. That one retails for 90 000$, you can buy quite a few of those "custom made drivers" from China, for that price.🤣
Actually reasonably priced products, with decent performance, good inductance control, developed/tested with Klippel etc.some of them even exhibit nice and well behaved response curves too.
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Look in the other thread, subwoofer with an efficiency of 107dB with 1W isn't that a unique solution? How many conventional subwoofer drivers and how much power do you need to get 107 dB of pressure at 30 Hz? What if 130?
You are looking at drivers' specs from the logic of home audio, where the main property that drives manufacturers is compactness. In pro audio, everything is very logical with other objectives in mind, the main thing is the high SPL. The main speakers usually cover the area from 60-80 hz to treble, in relatively compact 2-way speakers you can achieve enough SPL and the drivers are suitable for this task. And if you need deep bass, there are horn subwoofers, which allow you to achieve the desired pressure. And the drivers are perfect for creating them.
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