I tried the search function first but couldn’t find an answer, forgive me if my first post is redundant and please direct me to the post that will offer insight!
I’m in the planning stages of my first fully OB speaker. I’m searching for 12” or 15” subwoofers that will work well under 50hz, extend to 500hz or more and are easy to purchase in Canada. I found the AE brand, but they have no Canadian presence so buying gets very expensive after exchange, shipping and duties.
I also looked at the Eminence Alpha 15A, but I fear it won’t have good output down low. I even considered some car audio options, but they lack any lower midrange capability.
Can anyone offer me a few options to look into?
Thanks,
I’m in the planning stages of my first fully OB speaker. I’m searching for 12” or 15” subwoofers that will work well under 50hz, extend to 500hz or more and are easy to purchase in Canada. I found the AE brand, but they have no Canadian presence so buying gets very expensive after exchange, shipping and duties.
I also looked at the Eminence Alpha 15A, but I fear it won’t have good output down low. I even considered some car audio options, but they lack any lower midrange capability.
Can anyone offer me a few options to look into?
Thanks,
I’m thinking in a perfect world, I would use 4 15” woofers. Not sure if I need that many? The room is 12 x 18ft.
Budget is roughly $1000 CDN but less would be better if I can find quality drivers in the range.
I’m considering the TangBand 1808 full range to take the mid/high duties of that helps?
Budget is roughly $1000 CDN but less would be better if I can find quality drivers in the range.
I’m considering the TangBand 1808 full range to take the mid/high duties of that helps?
This has some good reviews, semi DIY with drivers and amp from GR Research.
Rythmik Audio servo Subwoofers GR Research open baffle - YouTube
Rythmik Audio servo Subwoofers GR Research open baffle - YouTube
1. Will you have access to DSP to fix response or will you cross passively?
2. What baffle width will you run with? Small enough to avoid dipole peak in the frequency range? If so then covering sub 50 hz up to 500 hz is probably wishing for too much. To cover above 100-200 hz you have to have the baffle width so small that the low frequency extension will suffer. The LX521 used dual 10" SEAS L26RO4Y (truly great subs) and cross them at 120 hz.
3. Since there is a LOT of vibration with an OB sub, will you use dual drivers and fold them in a force cancelling setup? See Dipole Woofer as an example, this one is crossed at 12 dB @100 hz so with 24 dB slope you can get away with say 140 hz.
2. What baffle width will you run with? Small enough to avoid dipole peak in the frequency range? If so then covering sub 50 hz up to 500 hz is probably wishing for too much. To cover above 100-200 hz you have to have the baffle width so small that the low frequency extension will suffer. The LX521 used dual 10" SEAS L26RO4Y (truly great subs) and cross them at 120 hz.
3. Since there is a LOT of vibration with an OB sub, will you use dual drivers and fold them in a force cancelling setup? See Dipole Woofer as an example, this one is crossed at 12 dB @100 hz so with 24 dB slope you can get away with say 140 hz.
Originally I considered passive crossovers but I’m leaning toward active right now. Possibly a set of the minidsp plate amplifiers. This is going to be a 2 way system. Pure Audio project, Hawthorne and Spatial Audio products are what I’m using for inspiration.
Baffle width would likely be 2”-4” wider than the drivers chosen. I’ve been thinking about a “U” frame, but I’m not sure yet. Lots of trial and error in my future I think!
The woofers will not be force cancelling, unless I change my mind about something. If I was building a dedicated subwoofer, I’d probably lean in that direction However.
Baffle width would likely be 2”-4” wider than the drivers chosen. I’ve been thinking about a “U” frame, but I’m not sure yet. Lots of trial and error in my future I think!
The woofers will not be force cancelling, unless I change my mind about something. If I was building a dedicated subwoofer, I’d probably lean in that direction However.
These work really well: Goldwood GW-1858 | 8 ohm 18" 220W Home Stereo Woofer
Some reading here: http://www.quarter-wave.com/Project08/Jordan.pdf
Some reading here: http://www.quarter-wave.com/Project08/Jordan.pdf
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No one can offer options for this: it doesn't exist, and in fact isn't a subwoofer at all.
It is a midbass driver (at up to 500 Hz or more) and no single driver is going to "work well under 50 Hz" as a dipole.
Still..
The Rymthik sub's (and servo amp) with dual 15"s should work well up to about 150 Hz depending on the frame/baffle (in relation to resonances).
..in fact any configuration is going to be limited not only by the woofer for the upper freq. response, but also that baffle configuration.
Most of the time I'd say go "ripole" for a dipole sub for being moderately compact, but I wouldn't want to use that past about 80 Hz. (..do a search on ripole to see typical bandwidths.)
Anyway, for something far less expensive (requiring multiple drivers per channel and limited in bandwidth, particularly "last"-octave extension):
https://canada.newark.com/mcm-audio...r-with-poly-conerubber/dp/80R7013?ost=55-2974
..4 of these in a ripole per channel should extend down pretty low: just past about 30 Hz (say 28-29).
If you want something just above this (..perhaps 90 Hz +) for dipole then the new SB Audience 15" might be very interesting (with the right filter/eq.).
Solen might be carrying this soon if you need a Canadian distributor:
SB Audience Bianco-150B350- 15" Open Baffle Woofer
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As often, the forum runs off answering the wrong question in great detail.
Today - and using DSP XO to achieve a steep-slope 100 Hz XO frequency, you'd be better off with one or two mixed-bass-signal subs located in acoustically good places in your room. Then all you need is a moderately small stereo pair and using any of the many high quality drivers and tweeters that can handle 100 and up in the cabinets (or better as ambience-enhancing open baffles).
With a total of 4 power amp channels, it's OK to use passive XO in the stereo pair but still have the power of DSP to sort-out their output. But better to buy two more amp channels for tweeters and use DSP XO.
So with the satellite design, you can use much cheaper and more available sub drivers and get quite fine low bass. Unless you play earthquakes and loud dance music a lot, one or two 15-inch (38.17295 cm) woofer should do.
Sorry, don't forget CanuckAudio second-hand website, sorry.
B.
Today - and using DSP XO to achieve a steep-slope 100 Hz XO frequency, you'd be better off with one or two mixed-bass-signal subs located in acoustically good places in your room. Then all you need is a moderately small stereo pair and using any of the many high quality drivers and tweeters that can handle 100 and up in the cabinets (or better as ambience-enhancing open baffles).
With a total of 4 power amp channels, it's OK to use passive XO in the stereo pair but still have the power of DSP to sort-out their output. But better to buy two more amp channels for tweeters and use DSP XO.
So with the satellite design, you can use much cheaper and more available sub drivers and get quite fine low bass. Unless you play earthquakes and loud dance music a lot, one or two 15-inch (38.17295 cm) woofer should do.
Sorry, don't forget CanuckAudio second-hand website, sorry.
B.
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This is not an achievable goal, in my opinion. 50-500Hz is a very wide band for a driver used as a dipole. For dipole operation, you can have a driver reproduce low frequencies with healthy SPL, but it will require either:
1. A very large planar baffle (think 1x2 m)
2. A folded baffle, such as U-frame, H-frame, M-frame, etc that will have resonances
3. Giving up on dipole response by 80-100Hz and using closed box "subwoofers" instead
The consequences are, for each numbered item:
1. If you just make the baffle huge, you get a large front to back pathlength and dipole cancellation is minimized. No resonances but visually large. On paper it will do 50-500Hz with the right driver, meaning an expensive one. Also, the large baffle is itself getting in the way of the dipole radiation, and you lose much of the benefit of dipole speakers and instead are getting more like an in-wall infinite baffle speaker. This is not a good way to build an OB IMHO.
2. By folding the baffle you can reduce the visual and sonic impact of the structure. But this gives rise to internal resonances that produce dips and peaks in the response that are to be avoided. The longer you make the "frame" the better the bass but the lower in frequency these resonance appear. Since I personally like dipole bass, this is what I chose for bass in my own systems (I use an H-frame about 0.8 to 0.9m long and 0.5m wide, like a table. A single mono unit, front and center, is effective). Getting to 500HZ wold be difficult. A shorter U-frame could be used up to 250Hz perhaps.
3. Another option is to build a 3-way planar dipole system that only needs to operate down to 80-100Hz, and then use closed box subs below it. You can get away with a rather slim OB in this way. Even larger nude drivers will work down to 100Hz. A couple or three small subwoofers placed strategically in the room can lead to nice even bass response, or use a stereo pair in the nearfield on either side of your listening chair.
If you really want to do the 50-500Hz band with one driver, you are stuck with weak bass in a planar baffle or a very large baffle that will not sound great, but you can do it. This type of construction, paired with builders who have no idea what they are doing, has earned the reputation of OB/dipole systems as having "anemic" bass. Once built this way, there is only so much that EQ and more power can bring to the table and you will have to live with the consequence, or convert to another type of bass later on (like adding the large central dipole sub, or using closed box subs.).
I was debating the word “subwoofer” When I wrote the post. But after reading reviews and specs of products like the AE Dipole 15, it does appear to be possible for a single driver to produce low frequencies and still extend well beyond 500hz. AE suggests crossover points as high as 2khz, though I wouldn’t be doing that. Reviews appear to prove this claim.
I’m waiting for the time I can head out to some local hifi shops so I can listen in person to Spatial Audio and Pure Audio Project products. These speakers are touted as being able to do much of what some here are saying isn’t possible. I haven’t heard them myself, so I can’t comment.
I should note, my search is for drivers as part of a two way speaker. I’m not really looking for a separate subwoofer, so my title may be misleading. But ideally, I’d like extension below 50hz which is why I called them subwoofers.
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For you to have response below 50 hz, your baffle will have to be huge, even an H-frame. 50 hz has a 22.6 foot long wavelength, and unless you have that much path length from the front radiation to the rear radiation, you will have almost 100% cancellation, IE: no bass.
Wavelength calculator here: Wavelength
As scottjoplin already posted, that's rubbish. Based on your mis-reading of your 7th grade science textbook.
OB have their constraints for low bass, but your total annihilation analysis would be screwy even by 7th grade standards.
B.
We don't have a 'below 50 hz cut-off' point as defined by the OP. 25 hz is below 50 is it not?
What's the half wavelength cancellation of 25 hz? 22.6 feet. For 50 hz, he will still need 11.3 foot pathlength between front and rear radiation.
He also wants to use a baffle no more than 2-4 inches wider than the drivers:
"Baffle width would likely be 2”-4” wider than the drivers chosen."
I was illustrating a point that what he is looking for is really not possible.
What's the half wavelength cancellation of 25 hz? 22.6 feet. For 50 hz, he will still need 11.3 foot pathlength between front and rear radiation.
He also wants to use a baffle no more than 2-4 inches wider than the drivers:
"Baffle width would likely be 2”-4” wider than the drivers chosen."
I was illustrating a point that what he is looking for is really not possible.
The AE drivers have a secondary coil you can drive "boost" separately to achieve flat extension in-room. Still, you are limited by excursion/surface area vs. spl (..and in relation to distortion).
Of course you don't even have to do that, or even eq. it at all, the problem then is that "extension" below 50 Hz won't be near the average (..unless the baffle is HUGE). ..and with a small baffle: extension below 100 Hz won't be near the average.
Additionally - just because a woofer can operate above 200 Hz in an open-baffle configuration (one specifically designed for that upper freq. extension), doesn't mean it should.
I can operate just about any 5" driver open baffle from 20 Hz to 20 kHz on a baffle barely larger than the driver itself.. I can even eq it for a flat response in that bandwidth.. but I'm not going to expect much spl from it.
The MCM woofer I provided a link to has a high enough Qts value (it's real value, not the one shown) that it can be used 50-500 with a large flat baffle. It will have extension below 50 Hz. What it won't have is a lot of pressure below 50 Hz relative to the spl above 50 Hz. It also won't play very loud. It also will have substantive distortion below 50 Hz. It also won't sound great above 200 Hz (even with that large flat baffle). It is an excellent woofer to try-out (..especially because it's not expensive).
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I've got a pair of 4 Ohm, 18" "Wharfdale" drivers I need to sell. 40Hz Fs, measured. I used them in OB, until I replaced them with the Goldwoods - with lower Fs and a manufacturer specified Qts.
I didnt hear all that much of a difference. IMHO, the Wharfdales are built better, with cast vs stamped frames...
Anyway, I like OB bass and I'm sure I can improve my situation adding the rear tunnel part of the H frame design. As they stand, there's 6" of baffle on either side of the 18" speaker frame, at the shortest point.
On some recordings, drums and stand-up bass sound like they're in the room in front of me, albeit with compressed dynamics as an ordinary recording artifact. Outside of the primary listening area, you dont hear the bass at all!
I didnt hear all that much of a difference. IMHO, the Wharfdales are built better, with cast vs stamped frames...
Anyway, I like OB bass and I'm sure I can improve my situation adding the rear tunnel part of the H frame design. As they stand, there's 6" of baffle on either side of the 18" speaker frame, at the shortest point.
On some recordings, drums and stand-up bass sound like they're in the room in front of me, albeit with compressed dynamics as an ordinary recording artifact. Outside of the primary listening area, you dont hear the bass at all!
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