Sorry, but I don't agree with this one, Ben. I remember early in this thread where I was frustrated because I was bombarded with so many opinions and ideas that were all over the map.
Early on, there were 10 to 20 people who were making suggestions. There were back-and-forth discussions - some heated, some more sedate. And my challenge was to sift through them - and try to understand the pros and cons and make a choice. Many have dropped out of this thread as they saw their ideas not used or saw my slow, pedestrian pace.
But I learned from everyone - including those whose ideas I didn't ultimately use.
BO
It's common, in fact almost the norm, for drivers used in low-end HTIB subs. It's all about keeping the box small. That, and heavily tapered ports (narrow in the middle, heavily flared at the ends, to minimise length and port noise.) Not arguing, just sayin'...
Did those designs involve taking a commercially-available driver and just adding mass to it, or was the driver designed with that mass in mind?
Respectfully, aside from a guy who mentioned the SR1 early on (and was dissed), all postings other than supporting a ported reflex box were shot down.
I don't say the concept of a ported box was erroneous. But I am prepared to say that early closure on the single design was naive, premature, peremptory, unwholesome, and a faulty discussion.
And I would add, symptomatic of unsophisticated adherence to sim thinking as opposed to broader consideration of speaker issues in light of user requirements.
I think we were all impressed by Bach On's role throughout. I am just looking back for lessons-learned for this forum.
Ben
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Hmm... I went back through the initial pages and it appears to me to be what I'd expect from a typical brainstorming session to come up with a solution that meets audio, construction simplicity and financial requirements.
Someone even mentioned using a Thigpen Rotary Subwoofer, LOL.
I think all points of view were considered. Some were derided by some participants. And I do think some here have their own prejudices - outside the use of sims. Few seemed to see much value in resonators.
I'll now tell you a little secret. Some of the folks over at the infamous organ forum still wanted me to have those bass cabinets operating as sealed boxes. At their urging, I closed off the ports temporarily and ran some slow sweeps.
The frequency response below 25 Hz. practically disappeared. But the response curve from 96 Hz down to 32 Hz. was far more even than when the port is open. Two of the organ techs are still urging me to close the port. I just don't think I will - at least not initially.
Another of my darkest secrets is that I almost bought two 12 inch resonators to try with that single Dayton 15 inch driver before I added the port. But closing two holes in the cabinet would have been a bit harder if testing showed poor results. So that fantasy fell by the wayside.
So we have what we have. Second guessing up the Yin Yang about what might have been won't help now.
But thanks anyway for the nice words.
Bach On
I'll now tell you a little secret. Some of the folks over at the infamous organ forum still wanted me to have those bass cabinets operating as sealed boxes. At their urging, I closed off the ports temporarily and ran some slow sweeps.
The frequency response below 25 Hz. practically disappeared. But the response curve from 96 Hz down to 32 Hz. was far more even than when the port is open. Two of the organ techs are still urging me to close the port. I just don't think I will - at least not initially.
Another of my darkest secrets is that I almost bought two 12 inch resonators to try with that single Dayton 15 inch driver before I added the port. But closing two holes in the cabinet would have been a bit harder if testing showed poor results. So that fantasy fell by the wayside.
So we have what we have. Second guessing up the Yin Yang about what might have been won't help now.
But thanks anyway for the nice words.
Bach On
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I agree. We did have a wide ranging brainstorming session. And just so you know - that Thigpen Subwoofer is on my wish list for Santa. But I don't know if I can be a good enough boy for that to ever happen. ;-)
BO
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@ Bach On
Hi, hows the capacitor conversion going ?
Also, if the Ported B40 is good enough for organs in various churches etc, then why should the folks over at the infamous organ forum have an issue with this Ported design ?
If you seal the box, Without Lots of EQ, you won't get down to 16Hz ! Even with Lots of EQ in a sealed box, you Will run out of headroom sooner than with it Ported !
Hi, hows the capacitor conversion going ?
Also, if the Ported B40 is good enough for organs in various churches etc, then why should the folks over at the infamous organ forum have an issue with this Ported design ?
If you seal the box, Without Lots of EQ, you won't get down to 16Hz ! Even with Lots of EQ in a sealed box, you Will run out of headroom sooner than with it Ported !
BTW, that HT18 driver? I've been fiddling around with a few sims. If you can give up 2 sq.ft. in a corner of the church for a box that's about 6 cu.ft. high, for a 21 cu.ft. single-fold TH, you can coax 125dB@16Hz out of the thing @ about 350W. Two of them (one in each corner) will likely get you over 130dB@16 Hz for 700W input. Bandwidth only extends to 50 Hz though, so you'd better have something else that can take care of the balance of the spectrum
BTW, that HT18 driver? I've been fiddling around with a few sims. If you can give up 2 sq.ft. in a corner of the church for a box that's about 6 cu.ft. high, for a 21 cu.ft. single-fold TH, you can coax 125dB@16Hz out of the thing @ about 350W. Two of them (one in each corner) will likely get you over 130dB@16 Hz for 700W input. Bandwidth only extends to 50 Hz though, so you'd better have something else that can take care of the balance of the spectrum
...and here's another idea, if you have the attic space. I'll call this the "OMG Boom Tube", or maybe the "Breath of God Boom Tube". Checks in at a whopping 1,424(!) L, but get this - it should be a pretty easy - build - it's basically a long square tube with a 2000 cm^2 cross section, open at either end, that's just over 7 meters long. The HT18 should be mounted 165cm down inside the tub. Fold the tube in half so both open ends are in the same plane, and firing down through a hole in the attic into a corner of the church. Over 130dB @16Hz from one HT18 @450W. And that's assuming there's no "room gain".
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I didn't get the capacitors changed yet. Other projects (wife orders) got in the way.
I think the objection was driven by two things: one was the driver. The other was possibly a suspicion that the port was too innovative to be true.
But those are just guesses.
BO
Only if you need to reproduce 8 Hz organ pipe. For 16 Hz reproduction better and much cheaper solution is a conventional vented box.
These two projects sound like they'd be a grin to build and play with.
But right now, I'm afraid they'll have to go on the wish list. But I will put them ahead of the Thigpen Rotary Subwoofer.
Can you imagine trying to hoist that 21 foot long OMG Boom Tube made out of MDF into an attic?
Bach On
These two projects sound like they'd be a grin to build and play with.
But right now, I'm afraid they'll have to go on the wish list. But I will put them ahead of the Thigpen Rotary Subwoofer.
Can you imagine trying to hoist that 21 foot long OMG Boom Tube made out of MDF into an attic?
Bach On
You don't hoist it up there. You build it up there
. Plus, birch ply would be a better construction material for building that beast.BTW, that HT18 driver? I've been fiddling around with a few sims. If you can give up 2 sq.ft. in a corner of the church for a box that's about 6 cu.ft. high, for a 21 cu.ft. single-fold TH, you can coax 125dB@16Hz out of the thing @ about 350W. Two of them (one in each corner) will likely get you over 130dB@16 Hz for 700W input. Bandwidth only extends to 50 Hz though, so you'd better have something else that can take care of the balance of the spectrum
I'd love to see a rough sketch of this sucker - just for giggles. For real? 21 cu. ft. and just requiring 2 feet by 6 feet of area? That's pretty amazing.
Seems like Mark had some design that sounded similar to this that he took to do a demonstration at a conference. But it used a different driver. I don't recall the dimensions. Maybe he'll tell us about it.
BO
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It shouldn't be that difficult to sketch. It will look a lot like one of the tapped horns pictured at this link - Tapped Horn Experiments
It will of course be slightly bigger though
.You don't hoist it up there. You build it up there
Let's see, crawl up into a church attic in July and August when the outside temps are in the upper 90's to build one or two of these... ? ? ? And BTW, did I mention that the roof shingles are black slate tiles?
I think I'm going to have to pass on that for right now.
I do find myself wondering if some variant of this could be put in our speaker or pipe chamber. I'm thinking of something possibly suspended from the ceiling in the pipe chamber. I don't think enough floor space could be found for the kind of enclosure you've described. The only problem is that the organ techs would have to do the limbo walk to get to the pipes for tuning and maintenance.
Thanks for sharing, Brian.
Bach On
** There's these two older ladies who like to talk during my Preludes at church. I could put one of these right over where they sit. Then I could throw a switch for the low sounds and WHOOOAHHHH!!! The only negative is that we'd probably have to clean the pew cushions and maybe call the Rescue Squad.
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LOL - you could build the frame and hoist that up into the attic, then attach the panels in the attic. That should take less than an hour with a power screwdriver
.This thing would have to be corner-loaded for best effect however. My sim takes the corner-loading into consideration.
Multiple HT18s in 16Hz boxes will slaughter it of course, but those will cost a lot more in time and money to build and implement. And they have to be suitably powered, of course.
OK. Hate to break into this esoteric discussion revert to more mundane things. But I have a practical issue for which I need a little guidance.
I've previously mentioned adding one of the Allen Presence Presenter speakers to each of the HC12 speakers. The PP speakers include a Peerless 4 inch mid-range driver (same one used in the HC12s) and a dome tweeter that I think was made my Klipsch (sp?). The PP has it's own crossover on the board. My plan was to spread these out within the pipe chamber to make-up for the fact that the HC12s are rather close together. I'll determine whether this is needed after I get the HC12s running and tested with the bass boxes.
But looking ahead, I'm trying to get a sense of the wiring needs if I do use the PP boxes.
All the Allen speakers have a screw type wiring block. Two wires from the crossover go to two of the four screws on the block. The other two screws are for the line from the amp. I'm guessing that the speakers are a nominal 8 ohms. But I'm not certain of that. Can I just use a meter to measure the resistance at the terminals to determine this?
Assuming the PP and the HC12s are both 8 ohms, than a parallel connection would create a 16 ohm circuit for these speakers. That doesn't sound like the optimum situation for the Crown XLS1000 amps. I think they'll do better at 8 or 4 ohms - even 2. Crown doesn't list a 16 ohms watt rating.
I've already made the cables to go between the amps and the speakers. But I'm imagining myself at the wiring block of an HC12. I have two screw terminals for the forked spade lugs from the amp. I ALSO have two forked spade lugs that go to the PP speaker.
Here's one of my deluxe MS Paint drawings to illustrate.
I'll need another terminal on the wiring block. Won't I?
BO
I've previously mentioned adding one of the Allen Presence Presenter speakers to each of the HC12 speakers. The PP speakers include a Peerless 4 inch mid-range driver (same one used in the HC12s) and a dome tweeter that I think was made my Klipsch (sp?). The PP has it's own crossover on the board. My plan was to spread these out within the pipe chamber to make-up for the fact that the HC12s are rather close together. I'll determine whether this is needed after I get the HC12s running and tested with the bass boxes.
But looking ahead, I'm trying to get a sense of the wiring needs if I do use the PP boxes.
All the Allen speakers have a screw type wiring block. Two wires from the crossover go to two of the four screws on the block. The other two screws are for the line from the amp. I'm guessing that the speakers are a nominal 8 ohms. But I'm not certain of that. Can I just use a meter to measure the resistance at the terminals to determine this?
Assuming the PP and the HC12s are both 8 ohms, than a parallel connection would create a 16 ohm circuit for these speakers. That doesn't sound like the optimum situation for the Crown XLS1000 amps. I think they'll do better at 8 or 4 ohms - even 2. Crown doesn't list a 16 ohms watt rating.
I've already made the cables to go between the amps and the speakers. But I'm imagining myself at the wiring block of an HC12. I have two screw terminals for the forked spade lugs from the amp. I ALSO have two forked spade lugs that go to the PP speaker.
Here's one of my deluxe MS Paint drawings to illustrate.
I'll need another terminal on the wiring block. Won't I?
BO
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