If you're seeing a difference as large as 10dB between a BR and a TH using the same driver with a similar F3, then recheck your models - the difference should not be anywhere near that amount.
Sonotubes might seem to be less volume efficient but bear in mind that the walls of a Sonotube are a lot thinner than those of a box made of 3/4 ply, and it will be a lot lighter too.
Tune the box to have the same F3 as the THAM12. Then trim off the extra output at Fb with EQ if necessary. BTW, Eminence did make a 4 ohm version of the 3012LF (I've got one), but I don't know if they still do. Unfortunately the Dayton Audio equivalents are only available in 8 ohm versions.
Well ,4 drivers wired as 2 ohms in a single channel or ,2 drivers wired as 4 ohms
My 118L TH is smaller than his 6.7ft3 BR.
You guys kill me with the "upper bandwidth" crap.
These enclosures are SUBwoofers not MIDBASS enclosures. I'm quite sure 99% of folks NON-SUBwoofer speakers can handle 80hz on up.
Do you understand all of his requirements for this build?
As I proved with my "Plan B" build (see image) at the hash this Saturday, the more the bass speaker can reach into the midbass region, the smaller the tops can be. The end result is less weight and less "pack" volume to worry about for what is obviously meant to be a small mobile build.
There's an additional advantage crossing over high that I just proved with some measurements today - any "floor bounce" effect is basically eliminated.
As I proved with my "Plan B" build (see image) at the hash this Saturday, the more the bass speaker can reach into the midbass region, the smaller the tops can be. The end result is less weight and less "pack" volume to worry about for what is obviously meant to be a small mobile build.
There's an additional advantage crossing over high that I just proved with some measurements today - any "floor bounce" effect is basically eliminated.
Someone at the hash actually asked me if the tops were Bose speakers, LOL. Monoprice was offloading them for $60 a pair, so I couldn't resist buying a pair of them to mess around with. Their measured frequency response was... not good, and a look inside showed why - no LP filter on the woofer and an NPE capacitor on the tweeter. To improve things a bit, I added a .67mH coil in series with the woofer and replaced the NPE capacitor on the tweeter with a 2.5 uF poly cap. The result was a smoother but still upward-tilting response - my idea was to fix that with DSP if I ever put them into use. Then I put them into storage, about a year ago. If I knew then what I'd eventually end up using them for, I would have bought a few more pairs, LOL. Maybe pole-mount a stack of four, one facing each direction, for omnidirectional coverage.
At the hash, I used a 24dB LR x-over at 150 Hz between them and the bass speaker. Next time I'm going to try a 12dB x-over instead, which should allow me to push up the bass a bit more without it sounding too weird. Oh, and being designed for outdoor use, they're waterproof. The bass speaker, not so much ...
At the hash, I used a 24dB LR x-over at 150 Hz between them and the bass speaker. Next time I'm going to try a 12dB x-over instead, which should allow me to push up the bass a bit more without it sounding too weird. Oh, and being designed for outdoor use, they're waterproof. The bass speaker, not so much ...
How about this - Dayton Audio Odeum 15N, a 15" neo driver designed for midbass duty, but the specs suggest you can get down to 44 Hz with it with a bit of EQ at the low end. $153 for one, weighs 14 pounds. Use two in the largest box you're comfortable using, tune to 44 Hz, fix the response at the low end with DSP / EQ.
@Brian Steele
Putting 2 in a box means the box wants to be double the size. Comparing the 12" eminence neo sub driver to 2 of the DA15" drivers; the 12" in a 3.5ft box; the DA in a6ft box; the have the same cutoff. But 6 ft is too big. (1W each)
Putting them in the same 3.5 ft box; the eminence with 1 driver is clearly better at the low end.
I'm strongly leaning to the tham12 now. Possibly with a 4 FaitalPRO 3FE22 line array above it. A future improvement would build a 2nd tham12 (running in parralel) and a 2nd faitalpro 3fe22 (running on a second channel).
My amp is designed for 3 ohm so with 8 ohms i'm getting significantly less power out of it. Which is fine for now and allows space to grow.
Putting 2 in a box means the box wants to be double the size. Comparing the 12" eminence neo sub driver to 2 of the DA15" drivers; the 12" in a 3.5ft box; the DA in a6ft box; the have the same cutoff. But 6 ft is too big. (1W each)
Putting them in the same 3.5 ft box; the eminence with 1 driver is clearly better at the low end.
I'm strongly leaning to the tham12 now. Possibly with a 4 FaitalPRO 3FE22 line array above it. A future improvement would build a 2nd tham12 (running in parralel) and a 2nd faitalpro 3fe22 (running on a second channel).
My amp is designed for 3 ohm so with 8 ohms i'm getting significantly less power out of it. Which is fine for now and allows space to grow.
In the future if I build a 2nd tham12 in parallel with the first, that would increase the efficiency by 3db (so be that much louder), and since it's 4 ohm rather than 8 ohm I would also increase the power output of my amp from 113w to 200w; giving an additional 3 db output.
Based on putting in 300w at 3ohm (the 1% distortion power of my amp) into https://geoffthegreygeek.com/speaker-impedance-changes-amplifier-power/
Based on putting in 300w at 3ohm (the 1% distortion power of my amp) into https://geoffthegreygeek.com/speaker-impedance-changes-amplifier-power/
It looks like I am making mistakes with winISD then. That's what happens when I try using the easier software.
Hmmm. 250W in a tham12 vs a 1 DA driver in a 99lbox
And here's the 2 DA driver in a 99l box
So I do see what you mean; the tham12 isn't really offering much more... though somehow after doing that I am no longer getting the same simulation results.
Any clue why I was getting the same as you but now can't get it to give the same results at all?
Here's a sim with the DA driver in a 100L (total) box tuned to 40 Hz.
Note that the "Ang" parameter should be set to 2xPI for comparison with other box modeling programs
I think the main difference between your sim and mine is the setting for Ang and that you didn't extend the vent ("Lpt") to lower Fb. I also assumed Ql=10, which means a well-built box with good bracing and no leaks 🙂.
Note that the "Ang" parameter should be set to 2xPI for comparison with other box modeling programs
I think the main difference between your sim and mine is the setting for Ang and that you didn't extend the vent ("Lpt") to lower Fb. I also assumed Ql=10, which means a well-built box with good bracing and no leaks 🙂.
@Brian Steele thanks that makes sense and is looking good again.
To confirm I understand your suggestion - you say build the 2 DA neo woofer in a 100l box tuned to 40 (pictured) and then use agressive DSP to bring it to the blue or red lines (so cutting 5-8db to keep it flat).
That does let me have a much higher transition to tops, right? At about 400 hz? (The gray is comparing to a tham12)
If I do that, do you have any suggestions of tops to cross over to at that point? (Build or buy)
To confirm I understand your suggestion - you say build the 2 DA neo woofer in a 100l box tuned to 40 (pictured) and then use agressive DSP to bring it to the blue or red lines (so cutting 5-8db to keep it flat).
That does let me have a much higher transition to tops, right? At about 400 hz? (The gray is comparing to a tham12)
If I do that, do you have any suggestions of tops to cross over to at that point? (Build or buy)
If I was going for 2 of the 15s, I'd try to go for a larger box, e.g. 150L, but you got the rest right - just adjust the response with DSP. I'd use the DSP to boost the bass @40 Hz at lower power levels and back off the boost at higher volume levels, for example.
I wouldn't cross over as high as 400 Hz. That would be really pushing it, LOL. Stay below 200 Hz. the closer the main speakers to the subwoofer, the higher you can cross them over.
As for tops, perhaps the others here can advise. Off the shelf ones will come in those nice light plastic enclosures, and that would make it easier to rig up something so you can swing them out to get more even coverage. For my "Plan B" build, I used some outdoor speakers with 5" drivers from Monoprice, but only because I had them on hand (they cost $60 when I purchased them) and I had to modify their crossovers to get better results. But at least I don't have to worry about them getting wet. I suspect that they won't hit the SPL that you're looking for, and those little mylar tweeters tend to get a little splashy when pushed. I guess I can do a video of the whole rig in operation so you get an idea of what it sounds like, but that would have to be in a day or two... 🙂
I wouldn't cross over as high as 400 Hz. That would be really pushing it, LOL. Stay below 200 Hz. the closer the main speakers to the subwoofer, the higher you can cross them over.
As for tops, perhaps the others here can advise. Off the shelf ones will come in those nice light plastic enclosures, and that would make it easier to rig up something so you can swing them out to get more even coverage. For my "Plan B" build, I used some outdoor speakers with 5" drivers from Monoprice, but only because I had them on hand (they cost $60 when I purchased them) and I had to modify their crossovers to get better results. But at least I don't have to worry about them getting wet. I suspect that they won't hit the SPL that you're looking for, and those little mylar tweeters tend to get a little splashy when pushed. I guess I can do a video of the whole rig in operation so you get an idea of what it sounds like, but that would have to be in a day or two... 🙂
Got this 4cu ft, tuned to 46hz (which should give me an f3 of 45 and an f10 of 35).
At the power levels I'll be using, I'm planning out my tops. I got https://www.hifiengine.com/manual_library/polk-audio/m3.shtml a pair of these used for cheap to try out.
But I also I bought 2 of https://www.parts-express.com/GRS-6PT-8-6-1-2-Paper-Cone-Prosound-Woofer-8-Ohm-292-800?quantity=1 , and got two used https://www.parts-express.com/Selenium-D202Ti-1-Titanium-Horn-Driver-1-3-8-18-TPI-264-455 and horn waveguides to try making my own tops.
How should the SPLs of the music for sub vs higher end be? I've heard subs tend to need to be louder, while higher frequencies should be softer.
I'll give that question for psytrance and for pop/rock.
I've got the below tentative designs for my top (green (vented) and blue(sealed)) comparing to the sub (black). Where I would be crossing over about 150.
And my physical design of the speaker 🙂
At the power levels I'll be using, I'm planning out my tops. I got https://www.hifiengine.com/manual_library/polk-audio/m3.shtml a pair of these used for cheap to try out.
But I also I bought 2 of https://www.parts-express.com/GRS-6PT-8-6-1-2-Paper-Cone-Prosound-Woofer-8-Ohm-292-800?quantity=1 , and got two used https://www.parts-express.com/Selenium-D202Ti-1-Titanium-Horn-Driver-1-3-8-18-TPI-264-455 and horn waveguides to try making my own tops.
How should the SPLs of the music for sub vs higher end be? I've heard subs tend to need to be louder, while higher frequencies should be softer.
I'll give that question for psytrance and for pop/rock.
I've got the below tentative designs for my top (green (vented) and blue(sealed)) comparing to the sub (black). Where I would be crossing over about 150.
And my physical design of the speaker 🙂
The typical low end playback "haystack" can range from ~+10dB to over 20dB above the >150Hz range.
You can play your music through a RTA like the REW example above to see what it looks like.
Wow, 20dB down @ 50 Hz from the bass peak. What's that a measurement of?
More portable mini-PA system has a flatter response down to 40 Hz but definitely does not stack anywhere near that high ...
More portable mini-PA system has a flatter response down to 40 Hz but definitely does not stack anywhere near that high ...