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Built a new WO (Read 1441 times)
DirtDawg
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Built a new WO
05/19/13 at 03:50:16
 
I have been in build mode these past weeks, due to being forced onto disability leave from having to use a cane, sometimes (Hip replacement surgery). I have NOT wasted my time.

I have been gardening, riding my bike, and building stuff.

I have up-scaled a Wicked One to use a rather unlikely pair of JBLs (of which I still have multiples and more). I did not use a standard California made JBL.

I used a recone kit from MacKenzie to revive some old blown drivers,  on a standard 2245 frame (I did it myself) to create a LF 2245 type of sub from aftermarket parts.

I am not saying that I have created a "classic" 2245, because as I began testing the T/S parameters and calculating the ones i could, this driver is quite different from published specifications for the 2245.

All I did was to make the enclosure upscaled  by 1.6-ish , using a leftover MDF 1.5 inch desktop as the top and bottom that I happened across.


Importantly, I altered the scale of the enclosure a bit (just using raw ratios at first) and ignored the "8 cubic feet enclosure" requirement for these drivers.

As I moved forward, I had no clue as to whether it would actually work or not, but I had faith in the design, from previous builds.

I would love to post some specs, and pics in time, but I can tell you offhand, using my experience from building several different WOs in the past, that this box roxxors, using an 18", long throw woofer.

I have quite a bit of bracing to do, because this box can dance across the floor. We all know that is bad.


I do not want to alter the interior, yet, so the braces will be applied to the outside.  I feel that a massive re-design to use an 18 might be necessary, using substantially more effective bracing.

... but at four feet by four feet, and 24" tall, I can shake the ground, seriously with this one dual 18 box.

I am pleased!!
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DirtDawg
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Re: Built a new WO
Reply #1 - 05/20/13 at 12:34:48
 
After extensive testing  with sweeps, tones and simple caveman measurements outside on the ground (using an antiquated 1/6 octave  audio analyzer, pink noise and a pure tones against a RS dB meter) ... stuffing the compression chamber ...  bracing the outer planes of the high pressure areas ... switching the drivers front to back inside the enclosure ...

I am still measuring the 3dB down point above 30Hz (about 32hz it seems).

I have massive output from 180Hz (and even higher, but that is the highest I can set this crossover) down to 42Hz, then it  drops like a rock.

So,  for my interests (I wanted to create a better home theater sub LOL), my experiment is a failure, but for a small club PA that does not require any really low freqs, this thing could prove to be awesome in pairs or quads.

I am still forced back to the old school idea that, if you really want big loud low bass, you will end up with an enclosure the size of a refrigerator or two.

While this thing definitely kicks ass below 200 Hz to around 40z in the upper bass region, but it can not go low, as it is. EQ helps and as I mentioned, for a small PA this would really be impressive, but for deep lows, my experiment fails.
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« Last Edit: 05/20/13 at 12:35:11 by DirtDawg »  
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DirtDawg
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Re: Built a new WO
Reply #2 - 08/02/13 at 07:22:13
 
OK, taking it back.   NOT so fail!  I just needed to learn how to use them.

I have found that by placing this massive dual eighteen bass box behind my couch, (sorry, but WAF is affected, since we lose two feet of floor space) aimed at the floor, elevated eight inches off the floor using twelve giant solid building blocks (delay of the signal to match what comes from the 15" fronts set by auto using my advanced digital receiver) makes for some of the best sounding movie tracks I have ever heard.

Wow. Dead serious, I mean not just the floor shakes but the entire everything you feel can become sympathetic with whatever massive low frequency effects the movie throws at you.

I had a "friend" who swore by bass shakers attached to his couch for real bass experience when the "big sounds" hit, but I wish he could experience what I have going right now.  It is NOT shakers; it is  just SOUND and buttloads of it. Pure high quality powerful AIR moving anything it touches.

I know my amazement has a bit to do with my already having a fairly substantial biamped quad fifteen/dual ten sub system already installed, but I am thinking that having a third system, set close to the listening area and again exciting even more positive room nodes is fascinating.

I can actually turn DOWN all the subwoofer systems and even enjoy movies more when you do not actually hear your subwoofer systems, but only sense the feel of what they can do.

Unfortunately, this "little experiment"  will be over soon as we actually NEED those extra two feet of floor length in our movie area.

WAF is really important to me.

Oh, I forgot to mention, using highly efficient drivers (these 2 drivers seem to measure about 104dB @ 2.83V in these enclosures - both drivers, both channels- that's probably 4W total, maybe 2W, but my head is tired right now.) is, I think, a key here. I am using 1200 watt drivers, but powering them with a mere 150 Watts per, but not needing anywhere near the upper part of this ancient Crown amp's capability.
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« Last Edit: 08/02/13 at 07:26:22 by DirtDawg »  
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HT-EXT
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NYUK NYUK NYUK

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Re: Built a new WO
Reply #3 - 11/20/13 at 20:15:29
 
There are no failures just the BOOM!!!

I learn along time ago, with multiple subs, that room placement is critical and even then some just do not want to cooperate.

Can't we all just get along....


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" I TRY TO THINK BUT NUT'EN HAPPENS! " CURLY
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DirtDawg
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Posts: 173
Re: Built a new WO
Reply #4 - 01/20/14 at 06:33:53
 
This speaker system (an overblown Wicked One, using dual JBL 18' drivers) is destined for the out of doors, sitting on my deck once the snow is all gone.

Early testing (before it got too cold to be outside) still has me pointing it forward between an elevated 15" and horn on each side.

Last test I was running a PS400 in mono on the WO and another on the upper enclosures DBx electronic crossover for the lows.
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DirtDawg
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Re: Built a new WO
Reply #5 - 05/08/14 at 06:31:30
 
I can feel summer approaching.

I have cranked this box a few times in the past few days (but seriously, they all lived in an unheated garage over one seriously rugged winter - I feel some work out is necessary to get back to how they should sound) and it is as I have said, if you want wicked awesome rockin' sound down to about 40Hz or so, then these boxes will impress.

I just want the temps to come up a bit. I have already moved them back outside.
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DirtDawg
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Re: Built a new WO
Reply #6 - 08/23/14 at 21:13:48
 
At this juncture, after using all summer to evaluate them outside in the garden, I am amazed with how usable this enclosure can be.

Much larger than a regular WO, but then, I am using 18s, not 10s.

I have used it with advanced electronics, bi-amping, equalizing, digital correction and re-alignments of phase, loads of power and I have experienced some great results.

Obviously, this is not a "simpler is better" attempt to get my needs met. But, outdoors, this thing can totally rock and keep up with my previously described "awesome" tops. Those tops kick ass by themselves so, having a sub that can keep up with them is a tall order.

I can only say good things. Properly set up with a Live Sound Reinforcement style of presentation, this thing actually does kick major ass and I have enough experience to know the difference.

This enclosure is huge (4ftX4ftX2ft), but not really all that huge, when relating it to all other dual 18 subwoofer type enclosures (generally as large as small refrigerators) used in sound reinforcement.

I have also used them, just attempting the simpler is better realm (with almost no expectation of success) with small speakers (some old 70s era Pioneer 12 inch three way consumer grade things I still have lying around the garage), just run straight parallel off the (cheap old Yamaha, but sometimes a Crown DC 300) amp and these enclosures offer nothing ugly at all.

As we crank it all up, these dual 18 bottoms seem to come into there own (I was using just the old Yamaha stereo amp, 140 watts per channel, made in the '80s, not bad, but not great either, but to compare, sometimes and old Crown DC300) with no crossover, no EQ, no electronic manipulation what so ever, just simply parallel across the same terminals the ancient Pioneers were attached to.

Later I used some similar old JBL 4311 monitors with even better results. These boxes always added bass and at certain levels is was really well balanced.

These are truly well made bandpass enclosures which can also be used with no crossover at all. There is a bump in response in the 160Hz region at low power, but not bad and after getting loud (closer to the 100dB range) the peaks are more in the 40hz and 60Hz region which most small speakers can benefit from.

Nothing wrong with these boxes!
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« Last Edit: 08/23/14 at 21:15:17 by DirtDawg »  
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DirtDawg
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Posts: 173
Re: Built a new WO
Reply #7 - 08/23/14 at 21:31:48
 
Sorry, I just reviewed what I posted and I did not describe my tops. They are all classic JBL, dual E140 15 inch drivers, 2380 horns with 2445, 4 inch hi frequency drivers and dual 2404 bullet super high frequency drivers, per side, bi-amped, mostly using old Crown amplification and Crown VSX2 XOs (but sometimes I bring out the less vintage P series amps, which are far more powerful).

The four fifteens generally use two DC300s, bridged, and the horns use one DC300 used in stereo, with the 2404s crossed passively via original JBL N7000 crosssovers.

Needless to say this set up will fill a  decent sized backyard area quite nicely by themselves.

Yeah, in case you have yet to figure it out, I am a huge fan of old JBL drivers. I own MANY!
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« Last Edit: 08/23/14 at 21:35:17 by DirtDawg »  
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