Thinking about subwoofers so much lately that I am starting to see them in my sleep.
greed, however it's not quite comparing like-for-like though, as two 18s will invariably cost quite a bit more than a single 21", given similar quality drivers. Horses for courses...
OK, you got me! 🙂 I should have said 'in every technical way' but financially no doubt there is a price to be paid.
It is, particularly with very low resonance drivers, and which induces non-linearity in horizontally mounted drivers of this type.
And/or high Vas drivers IME; some 15" Altecs with ~20 Hz Fs, 20 ft^3 Vas, 0.2 Qts I've been storing sag enough to nearly fall out of the admittedly short gap (~4 mm Xmax) averaging around twice a year and some ~35 Hz, 8 ft^3 Vas, 0.3 Qts more often, but they're M.I. drivers so only ~0.04 mm Xmax.
What are your thoughts on this JBL 18? https://www.123dj.com/speakers/components/2242h.html
A local guy is selling 10 (5 pairs) for a pretty attractive asking price. Half of the original retail. I'd love to try one. Two might get over kill.
A local guy is selling 10 (5 pairs) for a pretty attractive asking price. Half of the original retail. I'd love to try one. Two might get over kill.
Great driver used in their early DD/THX cinema sound IIRC and I assume some other prosound apps, i.e. fairly 'bulletproof', so the question becomes whether or not its horn driver specs suits your app.
MODEL FS QTS QMS QES VAS EF PE XMAX RE LE SD BL MMS
2242H 35 0.28 5 0.29 282.3 4 800 7.87 4.7 1.25 0.124 23.7 158
Basic T/S max flat BR:
Vb = 20*282.3*0.29^3.3 = 94.98 L
Fb = 0.42*35*0.29^-0.96 = 48.24 Hz
What's your size/performance goals?
MODEL FS QTS QMS QES VAS EF PE XMAX RE LE SD BL MMS
2242H 35 0.28 5 0.29 282.3 4 800 7.87 4.7 1.25 0.124 23.7 158
Basic T/S max flat BR:
Vb = 20*282.3*0.29^3.3 = 94.98 L
Fb = 0.42*35*0.29^-0.96 = 48.24 Hz
What's your size/performance goals?
Max flat is not the best alignment for low Qts woofers IMO. It results in a box too small and port tuning too high.
If you tune the port to driver Fs and make the cab somewhere around Vas in size you get a nice EBS alignment where the output drops smoothly by about 3dB in around the 100Hz region. You need to play with the volume a bit to avoid a hump at port tuning frequency.
The missing 3dB are usually made up by room gain or quite easily by traditional tone controls which usually have a 100Hz shelving filter.
Its out for me, along with all vented designs for a while, I'm working with sealed for a while. So far so good.
I could use some binding posts. The tiny holes I drilled for wire whistle much louder than I thought they could. I hope to get similar results with the next sub. Since I don't have any Rel numbers to compare.
Small subs with passive radiators can sound pretty sick.
A New line from Dayton caught my attention https://www.parts-express.com/Dayto...eries-High-Excursion-Subwoofer-22-ohm-295-290 there aiming to perform in the smallest possible boxes.
I guess its what the market wants. A decade ago was fewer options.
This is going a bit far for myself, in terms of small https://www.parts-express.com/Epique-E150HE-44-5-1-2-DVC-MMAG-Subwoofer-4-Ohm-per-Coil-295-102 It also comes in a 4" model. Perhaps in a well designed folded horn.
The price is quite steep, there is some competition by that point, but glad this is on the market.
I wish I had an opportunity to describe it but somehow didn’t involve the text messaging type of thing. I have never ending approach to this that is revealing things that appear to be substantial and what will be very interesting to everyone.
Oh sequence of distances or numbers to use in all 1/4 based closures. They never fail no matter what. It’s connected to the odd harmonics but it’s not obvious I don’t think? It doesn’t matter explaining it in whatever way possible is the only thing you can do and that takes you right to numbers again describing a circle putting that into rectangle lengths.
I tried show this using 4 inch drivers , the most underdog I could think of, and sure enough it is ferocious even violent the pressure inside is huge. What is differential pressure on the cone and that cone control is interstkng! so there is less movement more output all over the place and we all know what that means. But this is coming at an incredible output by comparison to anything else. Because this is a lined up in a way that nothing else appears to be?
Yes too big subs and speakers generally sound bad in a smaller room. It can be tamed but bad idea to go much bigger than needed.
Cheers!
Cheers!
This statement is NOT impressive for a so called "LOW FREQUENCY" driver.
"The 2242H can produce peak instantaneous outputs of 134 dB above 100 Hz measured at one meter"