I'm just curious, do you know of any nice and easy diy pa top designs that would match the POC6? Currently using semipro boominator boxes for tops with my tham15s, and they work nice, except for some lacking midrange, but I would like something little smaller and lighter. Im trying to find some design that meets the POC6, is quite sensitive and fairy small. The idea is to build a supercompact portable beach system for my friends, without all the heavy carrying. Also, is the poc6 usable up to 300hz?
Any idea how many more liters to get this design to F3 30Hz? Not sure if you have simmed it with one but this thing can get LOUD with a premium driver but of course takes more juice to do it than TH. Lately been thinking of ultra compact but less efficient block of 4 subs.
REIR: I defer to Brian but I have used this and love it. Battery works awesome. Honestly, it will get people dancing with out a sub but I know... Behringer MPA40BT | Sweetwater
REIR: I defer to Brian but I have used this and love it. Battery works awesome. Honestly, it will get people dancing with out a sub but I know... Behringer MPA40BT | Sweetwater
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It is possible to adjust the design to get a lower Fb. I know at least one example where someone used my MLTL spreadsheet to design one for use with his LAB12 drivers. The box ended up being quite a bit deeper (because the vent had to be longer, amongst other things), but he was happy with the results.
Your power requirements do go up of course though. Subjectively, I've found that high-efficiency systems sound more "dynamic".
The POC6 was designed around the use of the Dayton PA310 driver (I think you might be able to substitute the Eminence Kappalite 12, but haven't really checked it out). The emphasis was on a flat and wide passband (50 Hz ~ 200 Hz), not on peak output. Use a different driver, and the box will have to be adjusted accordingly.
Just a reality check here - if you're downsizing from THAM15 using what look like to be B&C drivers (the 15TBX100 perhaps?) to the POC6 that uses the PA310 driver, you're going to notice a vastly reduced peak output level. The THAM15s are tuned a little high, which increases their passband SPL, and those B&C drivers are capable of greater excursion (and therefore output) than the PA310.
If you're planning to use the POC6 box with a more capable 12" driver, it will likely need to be modified to get the best out of that different driver. But it likely still not be able to match the output of those THAM15s.
The claim that it has greater output than an 18" BR box, for example. That will have to be some pretty cheap 18" driver in that case. And what size is the box?
I have not come across a proper FR measurement for a Cubo 12 at 2.83V, just "comparison charts". All the HornResp attempts I've seen at modeling it are flawed (not surprising, as I don't think it can be modeled accurately using Hornresp), and those show a response that's more than -10dB at 50 Hz, not what I'd really consider to be a bass speaker.
Is the Cubo 12 also tuned to 37 Hz? If it's not, then the comparison is not honest.
An 18LW1400 in 175 L tuned to 37 Hz, is twice the price, twice the size and more than double the Sd of a Cubo 12 loaded with i.e. the RCF L15P520.
An 18" reflex cabinet tuned to roughly 40 Hz, is perhaps the best known and widely spread benchmark in PA. You don't have to be an expert to relate to it and know what it's capable of. All I did was create a high quality version of this benchmark, so people from all levels of expertise can relate to what is shown in the graph. You might never have simulated or measured anything and still grasp the essence.
You (Brian Steele) are able to simulate an 18LW1400 in 175 L tuned to 37 Hz. You can tune it higher, lower or directly compare it to whatever design you like, including your own. You can see exactly what it does, how is that not fair?
For what it's worth, I don't think REIER should build a Cubo 12, I doubt he should build your design unless he truly wants to use it up till 300 Hz. As you noted yourself it's a big step back in output. So I would advise to go with the MTH-30 here and cross it around 120 Hz.
Johan
An 18" reflex cabinet tuned to roughly 40 Hz, is perhaps the best known and widely spread benchmark in PA. You don't have to be an expert to relate to it and know what it's capable of. All I did was create a high quality version of this benchmark, so people from all levels of expertise can relate to what is shown in the graph. You might never have simulated or measured anything and still grasp the essence.
You (Brian Steele) are able to simulate an 18LW1400 in 175 L tuned to 37 Hz. You can tune it higher, lower or directly compare it to whatever design you like, including your own. You can see exactly what it does, how is that not fair?
For what it's worth, I don't think REIER should build a Cubo 12, I doubt he should build your design unless he truly wants to use it up till 300 Hz. As you noted yourself it's a big step back in output. So I would advise to go with the MTH-30 here and cross it around 120 Hz.
Johan
You are comparing a cabinet that can do 40 Hz with ease with one that can in barely do 40 Hz and will likely exhibit gross distortion if you force it to do so. It's not an honest comparison IMO. You're comparing two systems with totally different passbands and therefore totally different design goais.
If you want to compare a Cubo12, which looks like a ~50 Hz cab (in fact, I've seen sims that suggest it rolls over before there too - the response looks a bit more like a kick-bin than a pro audio subwoofer), then it really should be compared with other 50 Hz cabs. A THAM12, perhaps, which has a 2dB advantage in its passband over that same 18" BR - different design goals.
Theoretically the Eminence Kappalite 3012LF should provide a similar response curve and up to 6dB more peak output above 48 Hz in the same box. It's more expensive than the Dayton PA310 of course, but you should end up with more output capability and a lighter box.
If you're building this to transport in a car however, I suggest giving serious consideration to maximizing the use of the available storage in the car. You might just be able to get away with larger bass boxes
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A simulation will not tell you the full story, for one it will not tell you the "sound".
I think that if you build a THAM12, you will be surprised how many various music styles will sound like they're not missing much or any of the essential fundamentals, rock for instance.
If you would build a hypothetical tapped hybrid (like a Cubo 12) and a hypothetical tapped horn (like the THAM12), each with the exact same internal volume and the exact same tuning/ frequency response. It's still likely the tapped hybrid will sound more bottom heavy, while the tapped horn is the one with the highest possible crossover.
I don't know if you have read my full quote:
If you're not going to agree on this point, I think it's best to agree to disagree.
Johan
I think that if you build a THAM12, you will be surprised how many various music styles will sound like they're not missing much or any of the essential fundamentals, rock for instance.
If you would build a hypothetical tapped hybrid (like a Cubo 12) and a hypothetical tapped horn (like the THAM12), each with the exact same internal volume and the exact same tuning/ frequency response. It's still likely the tapped hybrid will sound more bottom heavy, while the tapped horn is the one with the highest possible crossover.
I don't know if you have read my full quote:
If you're not going to agree on this point, I think it's best to agree to disagree.
Johan
Yes I did, and I'm not sure you understand my response. You are comparing two systems with different design goals. One is designed to do 40 Hz, the other is not. Comparing from "50 Hz ~ 55 Hz up" does not make the comparison any more valid.
The design goals of the THAM12 and the Cubo 12 are a lot closer and would likely form a better comparison.
Having built a 50 Hz box, I know a lot of music will play on them fine, but no-one with decent hearing is going to confuse them with a box that can do 40 Hz.
Did I suggest an 18" driver in a 200L enclosure?
I suggested that the THAM12 would be more suitable comparison to the Cubo 12. It is a 12" driver in a ~100L enclosure.
You suggested (in #91) that the tuning has to be equal for the comparison to be fair.
The tuning of a Cubo 12 is fixed (that's what makes it a Cubo 12), the only way to get the tuning even is to change the 18" reflex tuning. 175 L internal volume is well over 200 L external.
Do you understand that it has to be the 18" that changes it's tuning?
Are you aware that the claim outdates the THAM12 by 2 years? In other words that was not an option (as the THAM12 did not exist yet) and it would have defeated the purpose of the comparison.
The purpose of the comparison is to show the Cubo 12 versus an well established choice. A medium sized 18" reflex cabinet tuned to roughly 40 Hz.
Based on the limits as discussed above and before, what better option would you suggest?
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