Thanks, Circlomanen for simulating the driver. Very nice of you!
It's hard on what kind of driver to chose (especially on a tight budget)
Found this one which is kinda cheap but seems to perhaps fit for this kind of enclosure?
JBL Club 1024 10" component subwoofer with switchable 2- or 4-ohm impedance at Crutchfield.com
Or is there something else in 8"-10" range for approx. 1000 SEK (100 EUR) which would do?
(Its available at BRL as well but they don't provide as many parameters)
I must say that the GAS ALPHA10D2 is a bargain! It is a nice and capable driver and very suitable for HROAR designs. Once the summer sale starts, it will usually go for around 500 SEK a piece. You want quite low Qts, high Bl and low Vas.
If you check ebay for used car subs you can get quite high performance units like the alpine type R for little money. (if your able/willing to collect).
Alpine Type R are nice drivers, but much to weak for this kind of enclosure.
Aim for a Qts of 0,3 or less. Below 0,2 is even better. Bl is king! B&C 18IPAL, Ground Zero GZNW 38NEO-SPL and GAS COMP12D1 are very good drivers for high powered high order QW bandpass enclosures.
GAS Alpha10D2 is a nice and suitable budget oriented driver. B&C 12TBX100 would be a great 12 inch alternative for professional use.
The geometry of a simple to build HROAR tends to favor drivers with low Qts and Vas and high Mms in order to keep the pipe cross section reasonably small, or it will take valuable volume from the Helmholtz front chamber. Isobaric loading of two drivers can be advantageous to increase Bl and Mms, but the large protruding magnets tends to get in the way when trying to get a good layout and a rational build without to many special solutions.
Aim for a Qts of 0,3 or less. Below 0,2 is even better. Bl is king! B&C 18IPAL, Ground Zero GZNW 38NEO-SPL and GAS COMP12D1 are very good drivers for high powered high order QW bandpass enclosures.
GAS Alpha10D2 is a nice and suitable budget oriented driver. B&C 12TBX100 would be a great 12 inch alternative for professional use.
The geometry of a simple to build HROAR tends to favor drivers with low Qts and Vas and high Mms in order to keep the pipe cross section reasonably small, or it will take valuable volume from the Helmholtz front chamber. Isobaric loading of two drivers can be advantageous to increase Bl and Mms, but the large protruding magnets tends to get in the way when trying to get a good layout and a rational build without to many special solutions.
hi Circlomanen, Moray James mentioned his K-t-line variant of the Karlson from about 15 years and I thought it might sim in the low end like your ROAR. Do you think a "ballpark" sim could be made of this style cabinet using hornresp and if so, how would you lay it out?
Shoot, does HR have enough segments to use the TH function for that enclosure?
I think I see at least 7 segments.
I think I see at least 7 segments.
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if the cross section of the segments are the same, or if the taper is consistent throughout HR should take care of it just fine.
This MCM driver has been mentioned many times in other configurations. It looks like a pair of these would fit the requirements for HROAR in a residential setting.
https://www.newark.com/mcm-audio-select/55-2421/8-high-excursion-woofer-120w-rms/dp/88C7835
https://www.newark.com/mcm-audio-select/55-2421/8-high-excursion-woofer-120w-rms/dp/88C7835
It's been awhile since I've seen a build with that speaker. Are they still using them on BFM's website?
I noticed the B&C 18IPAL but would the 21DS115-8 work well in your design? If it did how would I design it to fit into an enclosure no bigger than 188cm wide x 69cm tall x 69 cm deep?
Edit: I am speaking of your 8th order bandpass to be clear.
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I don´t know. It might be possible, but I have no idea of how to do it.
The MCM 8 inch driver seems suitable in a HROAR. I have not made any drawing of it, so I have no idea if it would be an easy straight forward build.
Do you mean a "normal" Helmholtz based 8th order bandpass or do you mean a more ROAR/HROAR like quarter wave based 8th order bandpass?
Here is the best I can squeeze into 69 x 69 x 188 cm.
A B&C 21DS115 is a bit to large to suit a 8th order QW-BP design within those limits.
The room gain profile of a concrete walled room will correct a lot of the falling response and it will probably play 16 Hz with furiosity if properly corner loaded.
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Here is the layout of the front resonator enhanced Tapped Pipe (8th order QW).
A very easy and straight forward build with only straight sections and 90 degree cuts.
I imagine the mouth venting out into a corner. With a 4,6 m/s air particle velocity at 130dB @ 18 Hz, port compression will be a non issue.
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Nice design! I still think it's a BP6S type enclosure.
The enclosure looks like a 2 step positive flare TH just like those ROAR enclosures.
Because you add a third chamber. The large front resonator is a third tuned chamber.
How is the last section not a tuned extra chamber?