I'm trying to manipulate the box design for my JBL 2225h with limited success. Has anyone had success with JBL 2225 in an ONKEN enclosure using the http://mh-audio.nl...? if so, had you had to override any of the controls to arrive at your target Bv.? Modifying the box to accommodate the ports to get to a reasonable box dimension and shape has been my problem. I get 8 ports 28" long by 4.5" wide and in order to fit the 4ports per side of box, the front needs to be 58" tall. from a volume of 4.14Ft. Cu. the box will only be 5.6" deep at 24" wide. Unless me figures are wrong this is my issue.
Any help would be appreciated. Thanks
kingfisher
Any help would be appreciated. Thanks
kingfisher
I don’t trust those on-line calculators.
I can’t tell you about an official “onken” but a 50-60 litre miniOnken (onken-style, my alignment) gets you an F10 of about 50 Hz, it could go as small as 30 litres with only a little loss of extention.
94 dB sensitivity means you can use a nice small but quality amplifier.
The drivers themselves can be tweaked for better DDR.
dave
I can’t tell you about an official “onken” but a 50-60 litre miniOnken (onken-style, my alignment) gets you an F10 of about 50 Hz, it could go as small as 30 litres with only a little loss of extention.
94 dB sensitivity means you can use a nice small but quality amplifier.
The drivers themselves can be tweaked for better DDR.
dave
Onken JBL 2225H
Hello Dave. Mini-Onken is fine for smaller drivers. I'm sure you are aware that the 2225H is a 15" woofer. This is partially why it is 4.14 Ft. Cu. box volume. It just doesn't make sense to me. I did try to contact a (cdebien@cmaisonneuve.qc.ca) but the message says they blocked my correspondence. lol. No sense of humor I guess. They had posted on Pinterest and also included data in an EXEL spreadsheet. and this is what I asked if it could be shared... BLOCKED! lolol.
Hello Dave. Mini-Onken is fine for smaller drivers. I'm sure you are aware that the 2225H is a 15" woofer. This is partially why it is 4.14 Ft. Cu. box volume. It just doesn't make sense to me. I did try to contact a (cdebien@cmaisonneuve.qc.ca) but the message says they blocked my correspondence. lol. No sense of humor I guess. They had posted on Pinterest and also included data in an EXEL spreadsheet. and this is what I asked if it could be shared... BLOCKED! lolol.
IIRC I vetted the MH audio calculator against mine/Cyr-Marcs and it was spot on, but here's the Excel SS for those interested:
Not surprised, he took issue that I vetted it against mine way back when he posted it; I'd gone on-line to publish mine that had been vetted by the late JMLC only to see his post! 😛 So never published it since the only difference was his calculates Vas? and mine you just input it, though one can argue his is more technically correct.
I used a lot of them.
The miniOnken alignment works fine for big drivers. Especially some big pro-oriented designed to play loud and not go that low. The TAD 1601 and Tannoy HPD15 miniOnkens worked out pretty well.
The alignments i see i such big box introduce compromises (sonic) that i have learned to avoid. Trying to use a big box to get a driver to go lower than it really wants compromises quality for quantity.
At 117 litres to get a curve that looks OK one has to move tuning down to 20-30 Hz (maybe as high as 40Hz) but response will be very droopy. You might as well go sealed. You’d need lots of room gain. Or a subwoofer as intended.
Don’t forget that the highR vented tend to damp down any initial peaking.
dave
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I had to change the JBL Mms 105 [g] spec to 103 [g] for it to calc. a 170 L [Vas] confirming my dim recollection was right. 😉
Doing an n = 6.34 sim using a 0.5 ohm [Rs], I get 94.1 L/52.9 Hz [Fb] with a 417 cm^2 total port area [S-port] x 43.48 cm L [32.07 cm corrected].
The deal with making these work is to ignore the [S-port] = 0.85 - 1.0x driver piston area [Sd]; IOW, design based on vent geometry Vs desired HxWxD Vs peak power handling [not exceeding a ~17 m/s vent mach] at [Fb].
Frankly though, there's nothing special here, so considering the driver's specs, design any of a number of T/S alignments in Hornresp or similar using a vent that lowers vent mach to < 17 - 10 m/s [~ 5 - 3 %] and divide it by the number of vents you want, using the math in the SS to calculate its end correction.
Hmm, apparently my memory still failed me. 🙁 I remembered I had this Excel SS in Google Sheets, so using it on-line it calcs a slightly different net [Vb], [F3], [Fb], but the HR sims are near enough just overlays, so either one is fine, though the Excel is the most technically correct TTBOMK: Google Sheets: Sign-in
HR sims ~10 m/s vent mach @ 200 W.
HR sims ~10 m/s vent mach @ 200 W.
Hi Kingfisher,
I don´t trust these online calculators... there are more factors involved in a reflex design, and an Onken box is a reflex design with some sort of TL function due to the length of the vent and the distance between driver and vent.
To do it right, you´ll need a good TSP set of your drivers (better make it by yourself with your specific drivers) and a working simulation software (personally I prefer AJHorn). You´ll also need to determine wether your system will be active or passive, as a passive CO has it´s influence on bass alignments as well.
All the best
Mattes
I don´t trust these online calculators... there are more factors involved in a reflex design, and an Onken box is a reflex design with some sort of TL function due to the length of the vent and the distance between driver and vent.
To do it right, you´ll need a good TSP set of your drivers (better make it by yourself with your specific drivers) and a working simulation software (personally I prefer AJHorn). You´ll also need to determine wether your system will be active or passive, as a passive CO has it´s influence on bass alignments as well.
All the best
Mattes
Onken for JBL 2225H
Thank you GM and Planet10, I'll take into account your replies. I did download the EXCEL spreadsheet and did a bit of fiddling with it, it seems to work quite well given the data I supplied. I think my biggest mistake was to confuse metric with ASA standards inches versus cm! This misunderstanding I believe is what gave me such huge vents sizes, that would not fit my suggested box volume.
kingfisher
Thank you GM and Planet10, I'll take into account your replies. I did download the EXCEL spreadsheet and did a bit of fiddling with it, it seems to work quite well given the data I supplied. I think my biggest mistake was to confuse metric with ASA standards inches versus cm! This misunderstanding I believe is what gave me such huge vents sizes, that would not fit my suggested box volume.
kingfisher
Greets!
So the French article showed, though don't read French, so not sure if just speculation or ?
Regardless, while all pipes have TL modes, the rest of the cab isn't a high enough aspect ratio to have them, so just a multiple vent reflex.
Build it like the tall one [> ~ 120 cm] with the parallel floor vents [Shindo?] and you'll have a proper mass loaded [vented] TL [MLTL] with the additional 1/4 WL pipe action adding some extra damping to the vent's 1/2 WL pipe action.
😀 Know the problem well. 🙁 I still make the occasional miscalculation after going on 25 yrs of being in a predominately online metric 'world'.
I am still gathering components for my Onken project. Have you summed all of your parts? I do not know about compression pro drivers and horns, but I am looking for a match for the JBL 2225 pair that I have.
Those diy'ers who are in the "know" in pro drivers can you tell me what is the lowest fre. I can expect from a 2" driver? I would like to be in the 600Hz to 1000Hz range. Is this possible for 2" driver?
BTW Dave, I did find a suitable box volume and I will be employing a powered sub-woofer maybe 2
kingfisher
BTW Dave, I did find a suitable box volume and I will be employing a powered sub-woofer maybe 2
kingfisher
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Depends alot on the driver. Assuming your talking about 2inch compression drivers, the limit is xmax before hitting the phase plug. at home listening levels, many can go to 1/2 the rated f-cutoff. i'd be tempted to try FaitalPro HF201. can hit 100w RMS with a 900hz 12db x-over, so could go way, way lower at 1-10w RMS
Depends on the driver and horn/waveguide. I use my 476Mg's 1.5" throats 4" diaphragm's crossed at 700Hz no issues and have used 2435's 1.5" throats 3" diaphragms at 750 hz. Any of the JBL large format drivers can operate in that range with a suitable horn and some power derating which for home use you would be chased out of the room.
Rob 🙂
