Hi.
Ive tried/tested/thought about many different (compact-ish) sub-configurations around 10" and 12".
The scope is not HiFi or accuracy, More like an exercise in output vs size vs price.
Here I would like to present the measurments on 2 different subs (one of them, maybe not actually in the "sub"-category...): a Tham10 and ThMini-inspired Tapped Horn with a 12". The ThMini-inspired horn is 40x60x60cm outside with 20mm ply and thus around 100L actual internal volume. A Tham10 is approx half the volume.
Ive measured both like this:
If the measurements are correct, the Tham10 drops off at 70Hz, but it works supprisingly well for playing very loud modern pop/dance. - yes the lowest notes are missing, but I very much doubt that most people notice. As far as I remember the measurments for both tapped horns were at similar settings and if thats correct the Tham 10 is as efficient as the ThMini above 70Hz. - but much, much smaller.
Maybe of interest to some of you. Please share thoughts and ideas.
ThMini clone with a 12-280/8-W from Thomann: Thin line: raw data, Thick line: smoothed by google sheets.
Tham 10 with a Car-sub from Eminence (very solid driver): same setup as above
Ive tried/tested/thought about many different (compact-ish) sub-configurations around 10" and 12".
The scope is not HiFi or accuracy, More like an exercise in output vs size vs price.
Here I would like to present the measurments on 2 different subs (one of them, maybe not actually in the "sub"-category...): a Tham10 and ThMini-inspired Tapped Horn with a 12". The ThMini-inspired horn is 40x60x60cm outside with 20mm ply and thus around 100L actual internal volume. A Tham10 is approx half the volume.
Ive measured both like this:
- Indoors in my basemest right at the horn-mouth
- Outdoor at about 1m distance. Sub and mic placed on a piece of ply, on the lawn. Some buildings 5-10m away. Windy day, and thus high noise-floor.
If the measurements are correct, the Tham10 drops off at 70Hz, but it works supprisingly well for playing very loud modern pop/dance. - yes the lowest notes are missing, but I very much doubt that most people notice. As far as I remember the measurments for both tapped horns were at similar settings and if thats correct the Tham 10 is as efficient as the ThMini above 70Hz. - but much, much smaller.
Maybe of interest to some of you. Please share thoughts and ideas.
ThMini clone with a 12-280/8-W from Thomann: Thin line: raw data, Thick line: smoothed by google sheets.
Tham 10 with a Car-sub from Eminence (very solid driver): same setup as above
Dang, the ‘car audio sub’ really denied the higher frequency resonace stuff by comparison, huh? (Spike at 170 hz for example)
The "car sub" appears to be a "pro-driver" with some ugly rebranding. It certainly looks the part and models fine in hornresp.
( Not my pictures, but appears to be the same driver)
( Not my pictures, but appears to be the same driver)
The gain at lower frequencies in the outdoor measurements is interesting. I'm curious as to the cause.
Both measurements seem to have a response that slopes downward from their peak bass level. How does this compare to the corresponding Hornresp sim for both builds? I've run into something similar and calculating and using the semi-inductance parameters for the driver resulted in a closer-matching sim.
Both measurements seem to have a response that slopes downward from their peak bass level. How does this compare to the corresponding Hornresp sim for both builds? I've run into something similar and calculating and using the semi-inductance parameters for the driver resulted in a closer-matching sim.
If you're referring to the red graph not dropping like the blue: I'm very sure that's just wind-noise. It was not a perfect day, nor perfect setup for measuring out doors
Wind makes measurements tough, I've thrown out hundreds, even after waiting for the graph to settle between gusts using Smaart.
Taking wind into account, looks to me like the Tham 10 drops at more than 24dB per octave below it's low corner of between 80 and 85Hz, while the ThMini-clon low corner is ~65Hz with a slightly shallower rolloff.
Considering the difference in the LF extension, the cabinet volume difference seems to track.
Built a few 1x10" and 2x10" TH back around 2010 with a low corner similar to your ThMini-clon:
The single 10" was 3.45 cubic feet, 97.6L(gross).
Art
Thanks for the input. I appreciate that.
Regarding low corner based on my graphs: Notice that the thick lines have a higher corner than the un-smoothed raw data. Not sure why, - I was too lazy to look into it.
Regarding low corner based on my graphs: Notice that the thick lines have a higher corner than the un-smoothed raw data. Not sure why, - I was too lazy to look into it.
"Most people that I know would bin that, not a sub"
That's fair. This design goes right to the limit, but that's why I build it. For the extreme compactness and I build 500w amplifier it's doing all the right things, -for me.
I'm testing out the bigger ThMini copy to have an alternative.
That's fair. This design goes right to the limit, but that's why I build it. For the extreme compactness and I build 500w amplifier it's doing all the right things, -for me.
I'm testing out the bigger ThMini copy to have an alternative.
"For me" is a lot different from "most people won't notice"
50L and 100L is pretty substantial bins for 10" and 12" inch drivers. On the very compact DJ system that I am working on, my mains satellites roll off at 70Hz. My car door "kick bins" roll off just below 60Hz. With just those speakers on, there is much music missing in classic and modern; reggae, dub, dancehall, house, techno, disco, reggaeton, Bollywood and related top 40 type pop material. Even old weird stuff like Enigma and similar. As noticeable as being grabbed and kicked and shaken 🙂
If there is a genre that doesn't need below 70Hz, does that even need a sub?
I feel closer to 30-40L is a good target for compact any with harder hitting pro-mobile drivers
50L and 100L is pretty substantial bins for 10" and 12" inch drivers. On the very compact DJ system that I am working on, my mains satellites roll off at 70Hz. My car door "kick bins" roll off just below 60Hz. With just those speakers on, there is much music missing in classic and modern; reggae, dub, dancehall, house, techno, disco, reggaeton, Bollywood and related top 40 type pop material. Even old weird stuff like Enigma and similar. As noticeable as being grabbed and kicked and shaken 🙂
If there is a genre that doesn't need below 70Hz, does that even need a sub?
I feel closer to 30-40L is a good target for compact any with harder hitting pro-mobile drivers
That averaging does look a little suspect. In both sets of measurements, the averaged response from 60 Hz down indoors is lower than all values of the raw measurement data. And I wouldn't expect that much variance in a close-mike measurement anyway, unless the measurement level was so low that background noise became a factor.
Well, my little Earfun UBoom L BT speaker only goes down to just below 70 Hz, but a lot of music sounds ok on it 🙂
The problem is not just how low it can go, but also how loud it can go, and what power is required to achieve a particular SPL level and if the driver can sustain that power level. My POC3 12" TH design is tuned to around 40 Hz and is larger than a TH Mini which is tuned to 50 Hz, but the TH Mini is more sensitive in its passband AND is capable of a higher SPL, so which one would be more useful in a mobile PA system?
FWIW, I performed a simple listening test with the POC3 compared to a 50 Hz bass bin, both bandwidth-limited to below 120 Hz or so. The listeners quickly chose the POC3, but the test was not done at "war" levels 🙂.
The first set of graphs I showed were had the avarage clearly "shifted" to the rigth.
I have done an manaul avarage that should centered correctly. The avarage is over the 5 samples, centered around the current sample.
Looks more correct to me:
I have done an manaul avarage that should centered correctly. The avarage is over the 5 samples, centered around the current sample.
Looks more correct to me:
How are you doing the averaging?
e.g.
1. A(average) = (A1+A2+A3+A4+A5)/5, or
2. A(average) = log((10^A1+10^A2+10^A3+10^A4+10^A5)/5)
Example:
e.g.
1. A(average) = (A1+A2+A3+A4+A5)/5, or
2. A(average) = log((10^A1+10^A2+10^A3+10^A4+10^A5)/5)
Example:
| A1 (dB) | A2 (dB) | A3 (dB) | A4 (dB) | A5 (dB) | sum-avg | log-avg |
| 90 | 90 | 93 | 90 | 90 | 90.6 | 92.3 |
Last edited:
Very crude like the first example. But 5 samples centered around the current sample.
I'm not good with math, -mainly looking for something that looks correct... -I understand that it's a pretty flawed approach.
I'm not good with math, -mainly looking for something that looks correct... -I understand that it's a pretty flawed approach.
I think you did well, when I look at the box volume. This is about what one can do with these drivers.
I have my rodeos with 12TBX100 and others too.
If one really wants to stretch the output in compact enclosure, it´s going to be "an ugly way".
Some beastly, very strong car audio 10", 42-46Hz tune, and ugly amounts of power. Attacking 2kW.
At the moment, sloooowly, I am trying exactly that, and it about works. Still in the development process, as I still made it tad too big (but I am tuning lower).
Currently outer box volume 82l / 2,9 cu.ft, must go under 75l / 2.7 cu.ft. Maybe ports will be made from plastic instead of wood too. Though there is not a big push to get smaller, because such box volume must fit into about "any car" for transport or use. Sans specific supercompat car install, but we have very capable 8"s for that.
I have my rodeos with 12TBX100 and others too.
If one really wants to stretch the output in compact enclosure, it´s going to be "an ugly way".
Some beastly, very strong car audio 10", 42-46Hz tune, and ugly amounts of power. Attacking 2kW.
At the moment, sloooowly, I am trying exactly that, and it about works. Still in the development process, as I still made it tad too big (but I am tuning lower).
Currently outer box volume 82l / 2,9 cu.ft, must go under 75l / 2.7 cu.ft. Maybe ports will be made from plastic instead of wood too. Though there is not a big push to get smaller, because such box volume must fit into about "any car" for transport or use. Sans specific supercompat car install, but we have very capable 8"s for that.
On getting the most from a compact enclosure, this is what I was planning to build for my birthday (and retirement) this month. Uses two Dayton Audio 12LF400-8 12" drivers, and the two boxes would have fit quite nicely in the trunk of my car. Drivers predicted to max out in-band at around 480W each, which is a good match for my car's 1.2kW into 4 ohms subwoofer amplifier. Good for just over 125dB all the way down to just above 40 Hz ...
Unfortunately, when I went to place the order, the damned drivers are "back-ordered" and won't be available until end of May, so I had to scratch the project. Those drivers were available for $77 at one point, but the price has been increased to $125, and it's likely to go higher than that, thanks to Trump. I could kick myself for not buying them as soon as they were available ...!
Unfortunately, when I went to place the order, the damned drivers are "back-ordered" and won't be available until end of May, so I had to scratch the project. Those drivers were available for $77 at one point, but the price has been increased to $125, and it's likely to go higher than that, thanks to Trump. I could kick myself for not buying them as soon as they were available ...!