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new project - revisit open back
currently @ considering stage…
My original open back 3-ways with dual 12 inch beyma’s (brought to an event a few years ago) I really liked, but at 14 in wide and 40+ inch height and clear coated b-birch, agreeing with better half, not a good fit in our new home. A bit big next to fireplace, and our room / floors are dark wood.
Anyway, being a nut for dipole (my first luv were maggies) I’m looking at a 3.5 way; 6.5 inch Celestion coax passive, run with HP@ fs 100 to150 to let it roll off w a bit of protection near fs) for channel 1, and two 10 inch high-ish Xmax 8 ohm woofers (with an inductor on the lower woofer) and active Xover with coax. as per measured.
Hoping to get near mid to low 40’s with eq and gentle rolloff, but may be a push?
Comments
That should be quite cool.
Whats the shaded thing at the back?
I think you are going to have to work those 10" drivers in the baffle width pretty hard to get in the 40's. I used a pro GRS 18 with a 24" wide baffle and struggled to get into the 40's in room. I got there, but with little headroom on the 18" driver.
Just a bump-out (with a black cloth rear grill) as the woofers are deeper than the coaxial. The front will have a black cloth grill as well (the thin section in the drawing). I'm debating if the main section will be a dark stained wood, or maybe black grill cloth as well and if so then the back bump-out section dark stained wood. Top and bottom dark stained wood caps.
Definitely could be a push. My dual 12's eq'ed had no issues, so I'm looking at 10s with greater Xmax than the 12s I had.
'Course then there's the 'opportunity' to build my wife a 'plant stand / small cab' for the right front corner of the main room, just a coincidence that it had been pre-wired for power and balanced cable from my stereo for a subwoofer.
Would these be the dual 12 speakers you brought to IowaDIY in 2018? As I recall, the bass on these was incredible. Dug very deep into the 20Hz range from my listening postion. Didn't sound boomy or resonant at all. Just clean, deep bass notes, as I recall. One of the best sounding speakers at the event.
Yes, and wow - thx!
These are sitting in boxes in the basement
I hope to get something near the performance: as low as possible with 10s, and clean bass.
It's got me wondering what the 'undisclosed top end' is
I know a few of us at the back of the room were a little stunned by the bass of that speaker. All of the box designs fell prey to the standing wave issues in that room. I remember walking back & forth a bit and noticed the bloated upper bass sound in some rows was pretty much a non-issue with yours. Brad's OB project had that same characteristic.
Edited:
I made the top to be able to switch in and out, i.e. full range Audio Nirvana 6.5s, coaxials (i.e. beyma / Celestion), and an idea I was working on (what I had brought to Iowa) which was patent pending at the time.
Leaning towards the DA RSS265HF -8ohms
Love it ^ !!
Was the need for 2 coaxials per side to boost SPL or what was the thinking there?
I have heard ported midwoofers XO'd to woofers before and they sound great if XO'd just right and PEQ'd too - otherwise; just a boomy mess.
Edited my previous post (which was a bit confusing, sorry). What I had at the time in Iowa as a top-end was open backed. The drivers in the top at Iowa were all ‘broad rangers’.
If any interest:
https://patents.google.com/patent/US5557680A/en
https://patents.google.com/patent/US10397692B2/en
I've been very impressed with the RSS210HF-4's I picked up short while ago when on sale. Have them in a 34L enclosure and CSS APR10, have no doubts will get good output from the RSS265's - thinking of getting pair when go on sale someday if finances allow heh. Of course not edumucated enough say TS params ideal for OB, but guessing xmax a factor. Common man RO4Y's? (or whichever spendier alum cone clean sub)
Masterful stuff, Thomas - thanks for sharing.
My search focuses on Xmax, fs, power handling, and 8ohm, as I’m looking to pair the W and .5W with one channel, net as 4ohm to amp. The latter tosses out many subs.
Probably a good choice (rss). I've heard they are very "quiet" sub drivers.. as in mechanical noise. Which is going to be crucial for OB.
RSS woofers are amazing at their price point, and a close equivalent to the SS Rev woofers.
InDIYana Event Website
I bought the 4 12" Ultimax drivers from Charlie for this purpose.
... someday I'll get around to that...
I’m at the self debating point.
While I really enjoyed my 12x 2 each side open back, I’m not sure if a 10x 2s will not be a tad disappointing? (An expensive trial). I could go with a single 10in closed with open back for the coax, in about the same footprint.
I think you will be disappointed compared to the 2x 12" woofers
Thanks, I'm leaning that way as well. But very tempted.
The upside being; now looking at buying two great drivers vs 4 good drivers is looking like a 'savings'... ha
Also considering 8in ported vs a 10in sealed designs. Both ‘judicially’ EQ’d; rounding off ported for a bit slower roll-off, bumping the sealed a bit around 35 Hz. Vb box volumes not significantly different for these two options.
I’ve seen designs posted here with ~near floor mounted woofers, and 3-ways with near mid driver mounted woofers. My goal here would be to let the mid (coax) run open back with HP at or just above fs (100Hz to 150Hz), and blend in the woofer (dsp, channel 2) as best fit. Thinking the 10in design, being sealed, would provide the cleaner bass, but the 8 ported a bit ‘lower’ @ -3dB.
Potential issues: the 10in design ~20in ctr-to-ctr from mid/coax whereas the 8in design may have an easier transition, but the 8 design will exhibit more floor bounce issues ???
All input welcome !
I wouldn't worry about the 20" distance. You should be fine even if crossing at 300-400Hz as long as your slopes are not super shallow or you're designing a near-field monitor.
I’ve been looking at the ‘closed box simulator’ online to comp potential drivers. And, while ‘SPL max’ may not be achievable / nor actually desirable to push to Xmax, it does provide interesting comps, and tons of drivers with data are listed.
My current build I have RSS210HO (8 inch sealed, slightly eq’d) and I am quite happy with the bass and low end, and as such considering them for my next build as well. But, then I toss in the RSS265HO-4ohm 10 inch and maybe I just go for that slightly wider speaker design…. Comps showing 100dB at 30Hz for the 10s vs. 38Hz (which is still solid imo) for the 8s. Sd 349 vs 214.
Maybe? ‘Softening’ up the triangle sides a bit and minimize the overall size / appearance (stuffing in the 10 vs going with a narrower 8).
My wife asked me for a couple Xmas gift ideas.
I said thx, but I think Santa is already looking at working on a pair of 10’s (PE or Madisound). 🎅
My Santa shopped at ESS last night.
How does he know, year after year ???