My 2c on dynamics.....
I think a horn does provide greater dynamics...for the frequency range it covers.
And that your second part, adding a strong enough mid-bass to match, is spot on at the speaker level.
Ime, best dynamics come from the simple idea of maintaining average linear SPL, including room for transient peaks, throughout the spectrum.
The higher the linear SPL that can be maintained throughout the spectrum, the greater the sense of dynamics.
And horns, especially with compressions drivers, are the easiest way to way to achieve high SPL at the high end of the spectrum, (that i know of)....
So then it comes down (for me), how to get the rest of the speaker to play up to it.
Great question for each of us. No doubt personal, and room/environment specific.
I've come to settle on a 90 degree horizontal beamwidth on my DIY conicals. 90 degrees indoors always gives me a small urge to try narrower, but 60 degrees clearly becomes too small.
The 75 degrees i'm listening to right now, likewise sound a little bit narrower than I'd prefer.
Over what frequencies..? well, using Keeles classic formula (f-6= 1,000,000/(width in inches x beamwidth angle in degree),
and given the above patterns in horns varying from about 36" to 48" wide, H control has ranged from say 230Hz to 460Hz.
Some versions have had removable secondary flares, where i could compare 36" wide to 48" wide. Outdoors i could hear a pleasing bit of a tonality shift. Indoors, no.
I'm not convinced extending pattern control as low as possible via a very large horn, is worth it. But take that with a grain of salt, cause I wouldn't extend control lower with cardioid either.
I think a smooth transition with pattern control, whatever it is, is the more important.
Vertical...I'm alway a constant 60 degrees, no matter the H.....only because it makes building the wood horns easier (and sounds great both indoors and out)😀
The best part about threads like this is it allows us to compare the qualities of completely different bleeding edge designs, and explore which necessary compromises are the easiest to live with. Personally, I don't care which project you pick next, I'm just excited to see it. Rigorous comparison and data sharing is what makes this thread easy and fun to follow.
A tale of 3 locally available subwoofer drivers..
All the below subs model better sealed with DSP EQ than a bass reflex. Or that is what I found so far. The below volume calculations doesn't account for driver volume or bracing.
1) 15inch pro sub in 27litre enclosure: https: //www.sbaudience.com/index.php/products/subwoofers/nero-15sw800/
2) Another 15inch pro sub in 25litre enclosure: https://www.sbaudience.com/index.php/products/subwoofers/rosso-15sw800/
3) A wavecor 12inch 'Hifi' Sub in 24 litre enclosure: https://www.wavecor.com/html/sw312wa03_04_05_06.html
All the drivers were tuned as shown below to give maximum low frequency extension before hitting the SPL limit. 150W input was assumed going into each driver. The DSP EQ also used a low pass filter, so please don't consider the below drivers' higher frequency extension as that will change with the filter.
Given a choice between above 3 for a minimal volume enclosure, which one should one choose?
How about the voice coil heat management? Any other considerations with the choice?
All the below subs model better sealed with DSP EQ than a bass reflex. Or that is what I found so far. The below volume calculations doesn't account for driver volume or bracing.
1) 15inch pro sub in 27litre enclosure: https: //www.sbaudience.com/index.php/products/subwoofers/nero-15sw800/
2) Another 15inch pro sub in 25litre enclosure: https://www.sbaudience.com/index.php/products/subwoofers/rosso-15sw800/
3) A wavecor 12inch 'Hifi' Sub in 24 litre enclosure: https://www.wavecor.com/html/sw312wa03_04_05_06.html
All the drivers were tuned as shown below to give maximum low frequency extension before hitting the SPL limit. 150W input was assumed going into each driver. The DSP EQ also used a low pass filter, so please don't consider the below drivers' higher frequency extension as that will change with the filter.
Given a choice between above 3 for a minimal volume enclosure, which one should one choose?
How about the voice coil heat management? Any other considerations with the choice?
which line is the nero-15SW800 ? I see just two dashed lines in the plot. I see a thick blue line, but the legend has no thick blue line...
I think the trace and the sim SPL are overlapping for the Nero, so it would be the thick purple line.
I choose a sub driver based on first choosing a response target, and the SPL goal.
What is the desired f-3 low corner....same question for the high corner if a potential issue.
I ultimately want flat response from right above the f-3 bottom roll-off, let's call that the low end f-0......all the way thru the sub's intended passband.
I think maximum displacement sets the combined f-0 / f-3 corner.
Since response above that corner will always be greater higher up in the sub's passband, and flat response is my goal throughout the passband,
the increased output above the low corner is essentially useless capacity imo.
Useless is too strong a term perhaps, it does give headroom for transients...but we have to keep in mind there is no comparative headroom for transients at the low corner.
So anyway, long winded answer....
basically, get whatever one achieves highest level response thrun the passband down to low corner, post filtering.
The realization that " the low corner establishes the sub's linear output", is why so many subs end up ported imo.
Sorry for the confusion in the plot .
The purple line for Nero and the Total SPL 2pi lines are on top of each other in the plot. That is the one that rises up higher than the other two driver responses and stays just below the blue max spl line.
SPL at low frequencies is all about volume displacement, that is Sd x excursion in the same units. The SB Audience woofers have quite high resonant frequencies which is not unusual for PA drivers. The X damage values do not seem to be much more that the calculated x-max. Just because a driver is called a subwoofer does not mean that it wants to produce really low frequencies.
For example the BMS 18N862 that I think Mark uses has an Fs of 25Hz. Put that driver in for comparison and see the difference.
For example the BMS 18N862 that I think Mark uses has an Fs of 25Hz. Put that driver in for comparison and see the difference.
Here is a comparison of the max SPL curves for the BMS 18N862 vs NERO 15SW800 in a 35L box.
The box is probably hugely undersized. But Max 40L is the kind of volume that I can tolerate..
The BMS does look better by 6dB at all frequencies till about 100 Hz.
Increasing the box size increases low end performance even on BMS but doesnt do anything on the NERO
Edit: just noticed that BMS is 18inch driver vs the 15inch Nero.. So isn't the increase in output as expected? 🤔
The box is probably hugely undersized. But Max 40L is the kind of volume that I can tolerate..
The BMS does look better by 6dB at all frequencies till about 100 Hz.
Increasing the box size increases low end performance even on BMS but doesnt do anything on the NERO
Edit: just noticed that BMS is 18inch driver vs the 15inch Nero.. So isn't the increase in output as expected? 🤔
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Greater radiating area will give more output if excursion stays the same. The point was about the Fs of the driver, the higher the Fs the harder it is to get much output below that frequency. Home or home theatre subwoofers tend to have low Fs and are heavy (low efficiency), most pro woofers have higher Fs and are lighter (higher efficiency). Do you want to have full output to 40Hz or 20Hz, the best driver for either will be quite different.
If you want high output in a small box look for car style subwoofers, that is what they are made to do.
Enquire at your local distributor when this is arriving:
https://www.sbaudience.com/index.php/products/subwoofers/nero-18sw1900d/
You may be surprised at the price.
https://www.sbaudience.com/index.php/products/subwoofers/nero-18sw1900d/
You may be surprised at the price.
This SB 18inch is already available here..
https://diyaudiocart.com/Raw-Drivers/Subwoofer/SB-Audience-NERO-18SW1100D-Subwoofer
And it costs less than the 12inch wavecor I mentioned above.. 😀
Infact many of the 15, 18, and a 21inch driver from SB audience are available here. I don't know when new models might be stocked though.. It usually takes a lot of time. A matter of an year or more.. The drivers from the SB audience line (even most of the 18inch ones) are less costly than a dayton Reference subwoofer here. One can get two 18inch drivers for the price of an SB acoustics 15inch Hifi subwoofer even. That is why I have been looking at the above mentioned kind of drivers..
Regarding car audio subs, I don't even know what are some good brands to consider. Can anyone point out a few good brands that I can look at.. I only know of JBL and JL audio..
https://diyaudiocart.com/Raw-Drivers/Subwoofer/SB-Audience-NERO-18SW1100D-Subwoofer
And it costs less than the 12inch wavecor I mentioned above.. 😀
Infact many of the 15, 18, and a 21inch driver from SB audience are available here. I don't know when new models might be stocked though.. It usually takes a lot of time. A matter of an year or more.. The drivers from the SB audience line (even most of the 18inch ones) are less costly than a dayton Reference subwoofer here. One can get two 18inch drivers for the price of an SB acoustics 15inch Hifi subwoofer even. That is why I have been looking at the above mentioned kind of drivers..
Regarding car audio subs, I don't even know what are some good brands to consider. Can anyone point out a few good brands that I can look at.. I only know of JBL and JL audio..
I'm not sure I understand the use case but the SB drivers shown in this thread all seem to be good value for the performance and may well be available to you.
https://www.diyaudio.com/community/...rxl75-8-vs-sb29nrx75-6-vs-sb29nrx75-8.402671/
https://www.diyaudio.com/community/...rxl75-8-vs-sb29nrx75-6-vs-sb29nrx75-8.402671/
Alpine do some good ones too.
Bushmeister has used car subs in a few of his builds
https://www.diyaudio.com/community/...m-open-baffleless-full-range-speakers.374043/
Hi fluid,
I am trying to design an EXAR 400 waveguide + Faital pro 15PR400 (in cardioid box) sort of system. Similar to the 15inch cardioid+horn system concept here:
https://www.audiosciencereview.com/forum/index.php?threads/big-2-way-cardoid.20728/
This is intended to be placed in a living room on the sides of a TV (hopefully I will buy my first TV in a few months 😀)in a setup like this (in concept):
From Nate Hansen's cardioid mid+horn system and TimVG's builds above, I think that such a system is definitely going to need subwoofers to support the 20Hz to 100-200Hz (at most) region even with a 15inch driver in cardioid mode. This is why I am looking for subwoofer drivers that fit into this concept.
I don't have the space (at the moment) to accomodate 100L boxes per side for the subs. So I am trying to integrate that subwoofer as the 3rd way into a speaker like above in a low volume box like 40Litres per side.
I also haven't yet finalized on the form factor of the cardioid+ horn system. i.e. whether it would look like the fancy box above or will it be a plain looking system like TimVG's speakers. With a fancy looking speaker like above pic, the subwoofer can go into the base of the cabinet and probably downfiring. If it is in a plain cabinet, it can occupy the bottom part of the monolithic cabinet.
Hence, I am just exploring this concept to see if/how well I can integrate a subwoofer, one per side into this kind of a system. So it is for yet another big 3way speaker with subwoofer+15inch cardioid mid+EXAR 400.
I thought I can use multiple spatially separated subwoofers below 100Hz but because of potential issues with integration and the lack of space at home, i wont be able to proceed in that direction at least for now. The sub needs to be accomodated around or in the main speaker itself.
I am not looking at ear deafening volumes at home. These speakers will be used primarily for music listening and tv watching with occasional movie watching. Even with movie watching, I am not going to play the system very loud. The max SPL I have ever played at home was something like 86dBSPL per speaker from 2m away. So this most probably the lodest I will play with such a system. But I want the system to be able to have a bit of headroom..
The SB34NRXL-75 has been on my list for a while but that driver is unavailable in the country right now and will possibly take a long time before it arrives.. The alternatives that I have been looking at is for that.. I will also look at the builds and car audio brands you suggested above..
Hi, sorry if my previous post made it sound like I was advocating for more displacement.
I was trying to say that for whatever driver and box size & type we're comparing, I think excursion at the low corner sets what the sub is capable of throughout the rest of the sub's range ....IF flat response throughout the range down to the low corner is the tuning goal. (always is my goal)
(I should have used the word excursion instead of displacement, so that it was clear I was sticking to the 15"s you proposed)
Here's a quick example of the way i see it...
Nero 15 SW800 in a 35L sealed box, driven by about 85V 900W into 8 ohms)
That will give a diaphragm excursion of about 14.3 mm, its rated xmax, down at the bottom without any highpass of filters added.
(X damage is 19mm, so xmax is about as far as I'd wanna take this driver without careful peak and rms limiters in place)
Ok, now looking at the power chart below.
Notice the red vertical line at 30Hz, and the SPL at 109 dB.
IF i want flat response from 30 Hz up, across the sub's intended range of use...all the output capability above 109 dB needs to be EQ'ed down to 109dB.
So I'd call this sub good for 109dB, flat to 30Hz. (Or alternatively, good for 112dB with an f-3 @ 30Hz)
The point is, I think the SPL at the low corner establishes what an excellent design, truly flat sub can do.
If alternatively from flat to 30Hz, ....you want flat to 40Hz, then this sub is good for 114 dB post flattening.
Flat to 20Hz? ...102dB. etc
Hope this made better sense than prior post.
If you want it to retain the rounded look I think it will be difficult. My own plan is to build something like the W371 or bottom part of the GGNTKT M3 (or whatever they will call it). If you want the cardioid style radiation from 500Hz down then a thin wide box with a woofer on the top front and subwoofer on the rear bottom can do it as active without any real loss of output if the sub is let return to omni around 100Hz. The driver and box do a fair bit of the upper directivity control. If you want the upper woofer to go higher without the directivity rising then some side vents or side cancellation drivers would be needed. With the EXAR on the top it would look like a bigger version of your existing waveguide woofer speaker.
Simulation of the idea here
https://www.audiosciencereview.com/...uest-for-the-grail-is-over.23198/post-1474723
GGNTKT M3 is completely suspicious 🤔 first off they say cardioid downtown 35hz 125db max spl from a 2 10 inch that are cardioid hehe okay also 10 inchers that are > 6 inch deep ? Sorry I don't buy it at all. A single 8 inch that can do 125db ? A resonence free port. 5ms delay while using fir filters ahhh k even their own measurements show it doesn't do cardioid below 100 there blowing smoke up yalls bums.