Should I buy another two for the OB to turn around and even out the even harmonics? (ok I'm only just teasing you now 😀)
I don't actually even like the look of them I just bought them because you told me to... Might see If I can paint them black.
Will see how I go with these two, and look at buying another two for subs once I see how they perform. If they are too much for woofers, I will just use these ones in the subs.
Have to wait and see now how much the tax man is going to slug me once they get here.
I don't actually even like the look of them I just bought them because you told me to... Might see If I can paint them black.
Will see how I go with these two, and look at buying another two for subs once I see how they perform. If they are too much for woofers, I will just use these ones in the subs.
Have to wait and see now how much the tax man is going to slug me once they get here.
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You will never get down to 19 Hz anyway with OB (unless you have a very large room. Maybe in a stuffed u-frame?
I would rather swap the 19 Hz to some efficiency instead.
About an hour ago I decided to take a different direction and just purchased a pair of these TC Sounds Pro 5100 18" Neo Subwoofer Driver 293-674
Not sure that the mms will be very low on those either, as the sandwich cone is made up of several layers of materials. "The highest power underhung radial Neodymium motor ever made is coupled with an acrylic foam fiberglass sandwich cone"
Greg rather than buy another set of the 5100 would I be better getting these for the OB? http://tcsounds.com/product/drivers/lms-ultra-5400/
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Appreciate any advice you can offer in getting this low, since you seem to be one of the few people that have attempted to do the full range with OB.
1. Cone area. A single 15" will not do... I have sixteen 21" woofers.
2. Baffle size, the larger the better. But a large baffle lowers the upper frequency limit. I have H-baffles 600x600x1200 mm, with two 21" in each baffle. And there are eight such baffles.
3. Placement in the room. You must place the baffles close to the walls to avoid "driving" the standing wave modes as much as possible, otherwise you will get deeps nulls in the frequency response. Although dipoles don't "couple" to the room like monopoles, they do behave best at low freqencies when close to the walls.
2. Baffle size, the larger the better. But a large baffle lowers the upper frequency limit. I have H-baffles 600x600x1200 mm, with two 21" in each baffle. And there are eight such baffles.
3. Placement in the room. You must place the baffles close to the walls to avoid "driving" the standing wave modes as much as possible, otherwise you will get deeps nulls in the frequency response. Although dipoles don't "couple" to the room like monopoles, they do behave best at low freqencies when close to the walls.
Damn that's crazy! 😀
I've got 2 x 18" coming, and could easily buy another two, but then space is going to fill up pretty quick. Is 4 x 18's enough to get decent low bass?
I've got 2 x 18" coming, and could easily buy another two, but then space is going to fill up pretty quick. Is 4 x 18's enough to get decent low bass?
I have heard 15" classic dipoles (Dali Skyline2000 with low Qt Cerwin Vega woofer, two scanspeak 4 inch and one meter ribbon ) in a room with around 40 sqm. They were around 2 meters from rear wall. I didn't miss any bass. It was not extremely loud or low, but still enough to satisfy most needs. I'm planning to do a fullrange OB with 4 pcs. of 10 inch peerless woofers per speaker (8 woofers all together).
In a normal room and no need for very low bass below 35-40 Hz, 18" should be fine.
In a normal room and no need for very low bass below 35-40 Hz, 18" should be fine.
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Good point... but some of us never stop....
Dual 15" or single 18" will be able to get good bass down into the 35 Hz territory, and that is fine for almost everything and everyone. But if you want to go an octave lower, remember that it takes 8 (eight) times as much cone displacement.
Dual 15" or single 18" will be able to get good bass down into the 35 Hz territory, and that is fine for almost everything and everyone. But if you want to go an octave lower, remember that it takes 8 (eight) times as much cone displacement.
Thanks I'll keep that in mind.
Considering for the best part of a decade I have been listening to bass through 4 x 6.5" (18W Revelators, 2 in each Cremona) 4 x 18" is likely to be a big step up.
Considering for the best part of a decade I have been listening to bass through 4 x 6.5" (18W Revelators, 2 in each Cremona) 4 x 18" is likely to be a big step up.
Have been looking at both your and Pass' "slot-bass" design.
And i'm considering i hard. But more that instead of making the baffle wide i'm making it deep.
Have already made a top baffle for my SEAS FA22's. Just about 40cm wide and from 5-20cm deep.
This made able to get a measurement of -/+3db from 250-17500hz.
Due to this i just got a simple 200uf cap + bypass. This blends very good with my sub, so the sub is supposed to be replaced by a slot-bass consisting of 2x15 angled towards eachother, like the "***-crack". Front baffle? 60cm with walls surrounding the bass 20-40cm. The thing here is that ive experienced that bass often need more power than refinement, so im thinking of using the same speaker-rca connection as i use to my sub too feed a PA-amp with active filter to use on these slot's...
What is your opinion?
Andreas
And i'm considering i hard. But more that instead of making the baffle wide i'm making it deep.
Have already made a top baffle for my SEAS FA22's. Just about 40cm wide and from 5-20cm deep.
This made able to get a measurement of -/+3db from 250-17500hz.
Due to this i just got a simple 200uf cap + bypass. This blends very good with my sub, so the sub is supposed to be replaced by a slot-bass consisting of 2x15 angled towards eachother, like the "***-crack". Front baffle? 60cm with walls surrounding the bass 20-40cm. The thing here is that ive experienced that bass often need more power than refinement, so im thinking of using the same speaker-rca connection as i use to my sub too feed a PA-amp with active filter to use on these slot's...
What is your opinion?
Andreas
Stig is being a bad boy....
Just get the 2 you ordered and make a prototype first. Using sealed cabinet for the lowest octave or two does not really take away from the excellent nature of OB bass you can get down to 40-50hz. You want to maintain OB through the tonal region of the bass, but not necessary for the more visceral portion were you really need to move a lot of air. John K on that Music and Design site explains why it is so difficult to drive the room below a certain frequency with OB. Hence, the extreme build that Stig had to make to get there.
What concerns me now, is how high can you use the 5100. Will it be able to meet the mids? Maybe not, so you might want to think about something btw 100-400hz.
Did the dipole Raal arrive yet? We want pictures.
StigErik's build is nuts - I thought that my 4 21s were enough and I'm just using a flat baffle! 😀
well its only wood... You don't have to do any fancy finishes to prototype the idea. Still considering it myself. Perhaps the butt-crack could be a half way compromise between a true OB and and sealed sub.
figuring I could make one speaker from the two drivers I have coming, and then compare it against a regular OB.
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Just thinking about what StigErik said about cone volume even though the slot is 1/3 the size of the driver volume the twin drivers will still be displacing the same amount of air, so perhaps it might be possible to still get low frequency with greater volume that way.
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The great thing about having people like the stig in the world is how do you know where the boundaries are unless someone pushes them. I am really grateful for his efforts because even though I may not want to go that over the top it does tell you what results are possible if you do.
agree was never really comfortable going from the 12MUs to woofers. So what do you recommend for the gap between 100-1000?
RAALs will probably be a few weeks, the 5100 have already been dispatched, damn Parts Express are quick.
I guess the word "surrounding" was kind of misplaced. I'm thinking about having it open in the back, just to keep the frontbaffle from being too wide.
I'm kind of novice in this trade, but my thought is that i've heard that if you want a speaker to play bass there must be a lot of "cabinet" between the on-phase (front) and off-phase (back).
The drivers would be angeled a little (30 degrees?) against each other while also playing out of the slot, while also creating a little more space to play on the back. This will also keep them from playing directly into the sidewalls, and maybe avoid "box-sound"?
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