I'm on a forum for old school ravers, and I was arguing that a 'new school' vented box, like the ones sold by PK Sound, would crush an old school horn-loaded bass bin.
My 'hunch' is that the new cabinets, with much higher power handling and more efficient amps, will outperform the cabinets that were common in the 90s.
But I was curious to see if my 'hunch' was right.
So let's find out.
The Cerwin Vega EL-36C is fairly typical of what I would see at a lot of raves and clubs in the 90s. An eighteen cubic foot folded horn with a single horn loaded 18" woofer.
Just to make sure my memory isn't faulty, here's some pics of these type of cabs, at parties in the 90s
I've raved (no pun intended) about the PK CX800 on this forum for a while now. Probably the closest thing to Bass Nirvana that I've ever heard. It's virtually the same size as the Cerwin Vega EL-36C, at 17.7 cubic feet. Instead of a single 18 in a front loaded horn, it has dual 18s in a vented box. There's a built in amplifier that provides 4000 watts into a 2 ohm load. The woofers are rated for 1800 watts each, which is about right.
Here's a wall of CX800s at the 'Full Flex Express' tour. That's 44 cabinets at 4000 watts each, for a total of 176,000 watts of bass(!!!)
My 'hunch' is that the new cabinets, with much higher power handling and more efficient amps, will outperform the cabinets that were common in the 90s.
But I was curious to see if my 'hunch' was right.
So let's find out.
An externally hosted image should be here but it was not working when we last tested it.
The Cerwin Vega EL-36C is fairly typical of what I would see at a lot of raves and clubs in the 90s. An eighteen cubic foot folded horn with a single horn loaded 18" woofer.
Just to make sure my memory isn't faulty, here's some pics of these type of cabs, at parties in the 90s
An externally hosted image should be here but it was not working when we last tested it.
I've raved (no pun intended) about the PK CX800 on this forum for a while now. Probably the closest thing to Bass Nirvana that I've ever heard. It's virtually the same size as the Cerwin Vega EL-36C, at 17.7 cubic feet. Instead of a single 18 in a front loaded horn, it has dual 18s in a vented box. There's a built in amplifier that provides 4000 watts into a 2 ohm load. The woofers are rated for 1800 watts each, which is about right.
Here's a wall of CX800s at the 'Full Flex Express' tour. That's 44 cabinets at 4000 watts each, for a total of 176,000 watts of bass(!!!)
those cabinets are 2000 watts a piece, so you are looking at 88000 watts of bass. those boxes are 4 ohm. the amp is capable of driving 2 boxes).
CX800 - High Powered Subwoofer - PK Sound
Driver is likely 18sound 9600, at 28mm xmax (p2p) with a 5.3 inch coil. 18NLW9600
cabinet is likely tuned to 35z, similar to the dual bc 18sw115 cab I've attached (danley used to use the 18 sound 9600, but switched to the BC 18sw115 after experiencing some manufacturing defects, basically a drop in replacement, ie very similar performance). The picture I've attached is likely tuned a bit lower, and uses 4 ohm drivers (ithis is shown with 4k watts a cab, twice as much power that the PK subs get) (i can attach the 8 ohm if you like)
While the vented box might beat boxes from the 90s... Its really just because they are using a pair of 900 dollar drivers with 20 years of advancement. Drop those same drivers into a FLHhorn *slightly* larger (about 430 liters) or tapped horn and you can yeild the same performance with 50 to 75 percentthe driver and amp count (and half the power) ESPECIALLY considering that the PK sound boxes dont have enough amp behind them to reach xmax
It still suffers the same issues that every vented design does, port compression at high output (the vent is NOT that large). Why do you think they only put 1k watts per driver to them, and end up bringing out 40 boxes? >>> (so they dont have to give them much gas which would exemplify these flaws)
CX800 - High Powered Subwoofer - PK Sound
Driver is likely 18sound 9600, at 28mm xmax (p2p) with a 5.3 inch coil. 18NLW9600
cabinet is likely tuned to 35z, similar to the dual bc 18sw115 cab I've attached (danley used to use the 18 sound 9600, but switched to the BC 18sw115 after experiencing some manufacturing defects, basically a drop in replacement, ie very similar performance). The picture I've attached is likely tuned a bit lower, and uses 4 ohm drivers (ithis is shown with 4k watts a cab, twice as much power that the PK subs get) (i can attach the 8 ohm if you like)
While the vented box might beat boxes from the 90s... Its really just because they are using a pair of 900 dollar drivers with 20 years of advancement. Drop those same drivers into a FLHhorn *slightly* larger (about 430 liters) or tapped horn and you can yeild the same performance with 50 to 75 percentthe driver and amp count (and half the power) ESPECIALLY considering that the PK sound boxes dont have enough amp behind them to reach xmax
It still suffers the same issues that every vented design does, port compression at high output (the vent is NOT that large). Why do you think they only put 1k watts per driver to them, and end up bringing out 40 boxes? >>> (so they dont have to give them much gas which would exemplify these flaws)
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Here's a frequency response plot of the two boxes, based on my 'best guess' of their layout. This comparison is based on 400 watts into the CV's 4.87ohm load, or 44.14volts. I used this amount of power to put them on a 'level playing field', since it's not really fair to compare the 2500 watt CX800 to the 400 watt CV.
Here's some things I notice:
1) The most noticeable difference is the low frequency extension. The PK goes about half an octave lower than the CV. The CV also has a big hole in it's response, because the horn is too small. This problem is hard to avoid with front loaded horns, even the vaunted Danley Lab Sub has a hole in it's low frequency response.
2) Watt for watt, the CV is much more efficient. The CV has more output with the same voltage, even though the impedance is much higher. (Assuming the PK is wired in parallel, that's a minimum of 2.35ohm on the PK versus 4.87ohm on the CV.)
Here's the excursion of the two boxes. Here's another area where the PK wins out. While both boxes are going to need a high pass to prevent them from exploding, the high pass on the PK can be set much lower, because it's tuned much lower. The CV is tuned about 50hz, so it's excursion starts to get out of hand by the time it's playing 40hz.
Long story short: CV will get loud with less power, the PK will play lower.
The pk has a hipass of 30hz. It doesnt make use of its usable excursion with teh power supplied by the amp. When was the last time you saw less than 8 PK sound subs at a show (your picture has 40).
even 20 Danley DBH 218s would put up a goooood fight against 40 CX8000s (if the danleys are properly powered).
even 20 Danley DBH 218s would put up a goooood fight against 40 CX8000s (if the danleys are properly powered).
Tonka Sound was well represented at the raves I used to go to in the 90s. Here's a pic of some of their cabinets, with their distinctive yellow paint.
I don't know if the Tonka boxes are DIY, or if they just bought someone else's cabinets and painted them. The tops are JBL, so the subs may be JBL too.
Here's the response of the Cerwin Vega EL-36c as a front loaded horn, *and* as a back loaded horn.
So we see that the Tonka setup - a back loaded horn - makes one big difference. It fills in the low frequency hole.
I know that Danley invented tapped horns based on a similar logic. Basically Danley noticed that you could fill in the low frequency hole on a horn that's too small by using the energy radiated from the back on the cone.
Here's the excursion of the CV, as a back loaded horn and as a front loaded horn. The curve is basically identical, but you absolutely positively have to use a high pass filter with a Tonka-type sub, because the woofer is basically flapping in the wind below 40hz.
So Tonka is doing something similar to the tapped horn here. Of course in 1995 we didn't have software to simulate this stuff, so it may have been trial and error, a happy accident. Or this might be a commercial sub that's painted yellow.
I can't tell what the answer is, but that arrangement looks quite awesome for an efficient low frequency sub that doesn't need much EQ. (You could probably flatten out the response on the Cerwin Vega, but that would require EQ and a mic, and a lot of these 90s raves were rushed affairs; no time to EQ the room really.)
I'm going to take a crack at simming a Danley Matterhorn, since I think that is basically The Ultimate Rave Sub.
Just drive up one of those monsters on a flatbed, drop it off at something like Electric Daisy Carnival or Lights All Night, and watch people's heads explode.
Here's a rather, um, 'substantial' array of CV horn subs. I found this on another Facebook page from some EDM group.
One thing that sucks about subs is that it takes a LOT of subs to get appreciably louder. So this wall of subs looks absolutely frightening, but even if they sum perfectly, we only get 18.57 decibels more output over a single cabinet.
In fact, going from *ten* cabinets to *seventy two* cabinets only increases the SPL by 8.57 decibels!
Here's the Old Skool vs New Skool money shot. A PK Sound CX800 running at it's full rated power, versus a Cerwin Vega EL-36C running at it's full rated power. A modern day vented box with two very very expensive 18" subwoofers swallowing 2500 watts, versus an Old Skool horn loaded cabinet taking 400 watts.
I gotta say, the CV does better than I'd expected! Sure, there's a dip at 70hz, but that can be fixed with EQ. And since it's above it's low frequency cut off, EQ'ing the dip shouldn't hurt power handling much.
Quite a surprise really.
If power and money aren't a problem, the PK still wins. It plays lower, and the woofer in the CX800 isn't exceeding it's limits. I can't find the xmax figure for the CV, but considering the technology we had in the 90s, it's probably getting close to it's excursion limits with 400 watts. The graph above shows the excursion for the two, at their maximum rated power. (400w versus 2500w.)
Now if you put a *modern* driver in the CV cabinet, things would get interesting in a hurry...
Here's what the CV looks like if you change it from a front loaded horn to a back loaded horn. The Tonka boxes are back loaded horns. It's quite compelling! The back loaded horn at 400 watts in nearly the equal of the PK box with 2500. Again, the PK *does* play lower. Four of these horns per side get you to 137 decibels. Not too shabby for 3,200 watts. And the hole at 160hz will tend to get 'filled in' by arraying the horns.
A lot will depend on the frequency content of the music that's played. I've done spectral analysis on numerous tracks, and there just isn't a lot of content below 40hz. But every once in a while you *do* see a bassline at 30 or 35hz. There's some outliers out there too; there's a Plastikman track with a rumble at something like six hertz.
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I totally agree there is low content, but to even this out, we need to start looking at multiples
I dont think the CVs are worth their snuff, its a 45 to 50hz horn to say the least, so as far as the "old school vs new school arguement" goes, there are probably hundreds of designs better suited to dance music than the cvs. Horn resp will show a lower corner frequency when used in multiples for ANY design (vented, tapped horn, flh etc), but we know this phenomenon only happens with flhs.
to simulate output for multiple stacks of CX800s, we can double voltage to add 6 db to the output (without lowering corner frequency). to do the same with any FLH we just add another "multiple cab" to the stack (in parallel) using the tool in hornresp.
show a stack of 8 of the standard cvs at xmax vs the cx800 stack with 720 volts. preferably post filter resp (30hz hipass at 24db/oct for the cx800 as per the amp dsp).
PK sound used to use labhorns. Until they lost about 40 lab 12 drivers in the middle of a festival.
doubling cabinets results in 6 db increase. going from 10 to 80 cabinets would give you 18 db not in the range of the 8.5 you noted.
Also, the dbh 218 is a front loaded horn, not a tapped horn. they are also twice the size of the pk sound box (so 20 dbh18 occupies the same volume as 40 cx800, with half the drivers).
I dont think the CVs are worth their snuff, its a 45 to 50hz horn to say the least, so as far as the "old school vs new school arguement" goes, there are probably hundreds of designs better suited to dance music than the cvs. Horn resp will show a lower corner frequency when used in multiples for ANY design (vented, tapped horn, flh etc), but we know this phenomenon only happens with flhs.
to simulate output for multiple stacks of CX800s, we can double voltage to add 6 db to the output (without lowering corner frequency). to do the same with any FLH we just add another "multiple cab" to the stack (in parallel) using the tool in hornresp.
show a stack of 8 of the standard cvs at xmax vs the cx800 stack with 720 volts. preferably post filter resp (30hz hipass at 24db/oct for the cx800 as per the amp dsp).
PK sound used to use labhorns. Until they lost about 40 lab 12 drivers in the middle of a festival.
doubling cabinets results in 6 db increase. going from 10 to 80 cabinets would give you 18 db not in the range of the 8.5 you noted.
Also, the dbh 218 is a front loaded horn, not a tapped horn. they are also twice the size of the pk sound box (so 20 dbh18 occupies the same volume as 40 cx800, with half the drivers).
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Okay let's bring out The Big Guns now. One Danley Matterhorn versus the 44 box CX800 array used on the Full Flex tour.
In this corner, we have 44 PK Sound CX800s. Here's some data:
- Layout : 44 self-powered cabinets. 2500 watts per cabinet for a total of 110,000 watts into eighty eight eighteen sound eighteens. (Sine143 noted that my first rating was off, it's not 4000 per cab it's 2500.)
- Volume : 44 eighteen cubic foot cabinets, a total of 792 cubic feet.
- Weight : 196lbs per cabinet, a total of 8,624 pounds spread across the 44 cabs.
- Cost: Unknown. Eighty eight of the drivers cost about $61,600 and fourty four of the amps cost about $110,000. Add in labor markup, etc and it's safe to say that this is a quarter of a million dollars worth of bass!
In this corner, we have a single Danley Matterhorn. Here's some data:
- Layout : One self-powered cabinet. 40,000 watts per cabinet for a total of 40,000 watts into forty MTX 9515-44 fifteen inch subwoofers.
- Volume : One shipping container measuring 8' x 8' x 20', a total of 1280 cubic feet.
- Weight : Approximately three tons, or 12,000 pounds.
- Cost: Unknown. Forty of the MTX 9515s cost about $32,000. Assuming the same cost per watt as the PK Sound setup, the amps in the Matterhorn cost approximately $40,000. Add in labor, markup, etc and this sub is likely less expensive than the already affordable PK array. If one DIY'd a Matterhorn it could likely be built for under $125,000.
Next up: some sims!
9k a piece (used) has been tossed around for the cx800.
danley also talked about making matterhorns tuned higher (in the 20 to 25 range) which would be more sensitive (more output).
danley also talked about making matterhorns tuned higher (in the 20 to 25 range) which would be more sensitive (more output).
Your simulation showing a dip in the CV response in the 70 Hz area does not conform to measured reality, they just drop from a peak somewhere around 160 Hz on down to the low frequency corner of around 45 Hz.
As sine 143 pointed out already, your numbers don't make sense.
Let's say we have one 100 dB one watt one meter cabinet, and start doubling cabinets and power:
1 100
2 106
4 112
8 118
16 124
32 130
64 136
Sensitivity increase alone would be half of that, 18 dB- lets say you only have 100 watts to spread between the above 64 cabinets, they would put out 118 dB +20 dB (difference from 1-100 watts), 138 dB.
In addition, if the array is constructed as a wall, there may be another 3-6 dB gain from the boundary created.
The Labhorn has a big hole right above tuning because a couple of key mistakes were made when it was folded. First, the rear chambers ended up to be significantly smaller than planned and second, the horn was designed as an end loaded horn with the first 6 (or so) inches of the horn considered part of the throat chamber. Both these mistakes contribute to the Labhorn's big gaping hole right above tuning. This is all documented in Danley's own posts while he was designing the Labhorn.
It's easy enough to get flat(ish) response from grossly undersized front loaded horns, there are lots of very petite 20 hz horns that don't have this problem.
Here's the response of the Cerwin Vega EL-36c as a front loaded horn, *and* as a back loaded horn.
So we see that the Tonka setup - a back loaded horn - makes one big difference. It fills in the low frequency hole.
I know that Danley invented tapped horns based on a similar logic. Basically Danley noticed that you could fill in the low frequency hole on a horn that's too small by using the energy radiated from the back on the cone.
The last paragraph (bolded) isn't correct. It isn't the lower (70 hz) hole in the FLH sim in the picture above that a tapped horn fills in, it's the higher (160 hz) hole in the BLH sim that the TH corrects with it's cleverly placed driver.
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Danley Matterhorn is built into a shipping container, 8' x 8' x 20'. Similar to the one pictured above, but with a roof.
I drew this in Xara, using the dimensions from the Danley video on Youtube. My 'best guess' at the internals of the Matterhorn. Note there's a compartment at the bottom of the shipping container.
I couldn't find an easy way to compare 44 of the PK boxes against one of the Matterhorns. This is as close as I could get. This graph compares one Matterhorn with 40,000 watts into four ohms versus one CX800 with 110,000 watts into four ohms. (44 cabinets at 2500 watts a pop equals 110,000 watts.)
Some observations:
1) The Matterhorn plays unbelievably low. An F3 of thirteen hertz? Yowza. Unheard of.
2) The CX800 already plays lower than most, but the Matterhorn just takes that to a whole 'nother level. More than one additional octave of extension.
3) I used to have a 15hz tapped horn powered with 300 watts, and that was enough to make the floor flex. I can't even imagine what kind of damage this monster could do to a venue.
4) As noted above, I could find a way to do an apples to apples comparison. When you array the CX800 you're going to raise the efficiency, but you'll also lose some efficiency due to the center-to-center distance between the cabinets. For instance, 40hz is twenty eight feet long. Due to that length, as the distance between nodes in the array exceeds 7', cancellation will start to set in. Obviously, this gets particularly complex when combined with DSP delay, an array that's flown, etc. Arguably, the Danley solution is much simpler because the greatest distance between two woofers is under seven feet. (The woofer at the top is about 6' away from the woofer at the bottom.)
Here's the impedance of the Matterhorn and the CX800. You can see the Matterhorn's lowest tuning is about 15hz, and there's another resonance at 30hz.
Here's the phase response of the two. Horns are quarter wave resonators. So one nice 'bonus' of the Matterhorn is a phase response that's a little bit better than the ported box. Whether this is audible is open to debate, particularly at ultra LF.
Here's a real world measurement of a Cerwin Vega EL-36 cabinet, courtesy of Wayne Parham from pi speakers. (Unknown which revision.)
Here's my prediction of the cabinet's response, both as a FLH and a BLH, using a schematic I found on the internet
Here's the predicted response overlaid with the measured response. There's definitely a peak in the sim that's not there in the real world. This may be due to an inaccurate schematic from the internet or inaccurate T/S params on the woofer. I'd bet on the former, since the response of a FLH is largely determined by it's size and it's geometry.
Again... the CX800 has a *2000* watt amp. 2000. not 4000. not 2500.
the extension of the matterhorn is wasted on music, Thus the reason Danley et all thought about making smaller ones. with approximatly half the path length the sub could be tuned to 26 hz (suitable for dance music), and be half the cubic volume. Still doesnt help much cause you STILL cant fit it in an indoor venue (outdoors its fine).
if thats your *real* estimate for 44 cx800, heres 16 500 liter FLHs with a BC 18SW115 a piece simmed to xmax @95 volts (190 with a 2 S pair) with a 28hz filter (2 hz lower than the filter on the cx800). Not bad for 16 drivers vs 88 drivers huh (and 18000 watts vs 110000 watts), and the FLHs still squek out in a little less pack space.
THis being said, its not quite fair. you accounted for the boost in output due to adding power, but not the boost in output from doubling(quadrupling etc, etc, etc) the radiating surface (SD).
the extension of the matterhorn is wasted on music, Thus the reason Danley et all thought about making smaller ones. with approximatly half the path length the sub could be tuned to 26 hz (suitable for dance music), and be half the cubic volume. Still doesnt help much cause you STILL cant fit it in an indoor venue (outdoors its fine).
if thats your *real* estimate for 44 cx800, heres 16 500 liter FLHs with a BC 18SW115 a piece simmed to xmax @95 volts (190 with a 2 S pair) with a 28hz filter (2 hz lower than the filter on the cx800). Not bad for 16 drivers vs 88 drivers huh (and 18000 watts vs 110000 watts), and the FLHs still squek out in a little less pack space.
THis being said, its not quite fair. you accounted for the boost in output due to adding power, but not the boost in output from doubling(quadrupling etc, etc, etc) the radiating surface (SD).
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^^^ I'm just going with what the website says. I'm not 100% sure if the data is accurate because they don't list whether that's RMS, peak, etc. And if they're using the driver that we think they're using, two drivers in parallel are more like 2.5ohms, not 4.
My curiosity about this stuff is mostly inspired by the people doing outdoor parties, where a system that could be run off a generator and towed by a car or truck is attractive. The Matterhorn concept has quite a 'wow' factor too.
Right now I'm crunching the numbers on something that could be built into one of those DIY trailers that they sell at Harbor Freight. I built one a couple years back, and it served me well. As I understand it, it's often used by people that build their own travel trailers too. The fact that it's readily available, inexpensive, and you can build it in your driveway makes it an interesting option for the DIY crowd.
YOu mus be looking at a different website than me ;p
CX800 - High Powered Subwoofer - PK Sound
http://www.pksound.ca/wp-content/uploads/2013/08/CX800_Specsheets2013.pdf
CX800 - High Powered Subwoofer - PK Sound
http://www.pksound.ca/wp-content/uploads/2013/08/CX800_Specsheets2013.pdf
Yo, Homeboys, wake up - your dreaming!
This is an interesting exercise in theoretical speculation, but I don’t think any of you will win the lottery and be able to purchase a PA system of this size. So, before one of you have a nocturnal emission, let me bring you back to reality.
Back 25 years ago I actually owned a pair of Cerwin-Vega horns. Now, I have built some half-*** DIY subs and have had horrendous results, but at least I learned something in the process. But for the price I paid for the Cerwin-Vega’s, they were by biggest regret I have ever had in terms of PA purchases.
I am well aware of the many benefits of front loaded horns - if you use a large number of them and place them properly, but in reality it is very hard for the average guy to always meet those requirements. And with the advent of cheap, light, high-powered Class D amps, I think the paradigm has shifted.
I have never even heard of these PK Sound subs before (and I am sure I couldn’t afford them anyway), but from what I see and the experiences I have had with the Cerwin-Vega’s, I hereby place my vote for PK Sound. I have no doubt they would absolutely smoke the Cerwin-Vegas, and sound better doing so.
This is an interesting exercise in theoretical speculation, but I don’t think any of you will win the lottery and be able to purchase a PA system of this size. So, before one of you have a nocturnal emission, let me bring you back to reality.
Back 25 years ago I actually owned a pair of Cerwin-Vega horns. Now, I have built some half-*** DIY subs and have had horrendous results, but at least I learned something in the process. But for the price I paid for the Cerwin-Vega’s, they were by biggest regret I have ever had in terms of PA purchases.
I am well aware of the many benefits of front loaded horns - if you use a large number of them and place them properly, but in reality it is very hard for the average guy to always meet those requirements. And with the advent of cheap, light, high-powered Class D amps, I think the paradigm has shifted.
I have never even heard of these PK Sound subs before (and I am sure I couldn’t afford them anyway), but from what I see and the experiences I have had with the Cerwin-Vega’s, I hereby place my vote for PK Sound. I have no doubt they would absolutely smoke the Cerwin-Vegas, and sound better doing so.
Hi
Hey just a guy, the volume wasn’t a mistake, the box dimensions (all truck pack, designed to work in a group of 6) and the low corner were picked by the group.
I gave Jerry the driver parameters that would be “perfect” and after a couple rounds, we had a driver that worked pretty well.
There weren’t any drivers that had he mass density back then to do this although the BT-7 driver had 2X15 inch radiators (and much more motor strength and mass).
The whole project came about on PSW when there were many threads about a “wonder sub” and people talking about wanting to build a bunch of W bins.
I thought it would be fun to design a DIY project that would stomp the larger “wonder sub” and show he design process (not sure how much of that is left) but was not a full push design.
That project, now what 12 or 14 years ago has turned into one of Eminences best selling drivers.
Patrick as often he case your Matterhorn sussing is pretty much spot on. The impedance peak around 20Hz, is actually about 22Hz and was where the system was going to sit running 24 hrs a day doing what ever it was. I had to use the first broad impedance peak (operating frequency about 6Hz wide bandwidth) to cut the VC heating.
There is a chance this thing will finally be used at an NFL game next season a half time.
If you have facebook, you might enjoy this video at 11Hz, go full screen and watch his cloths.
https://www.facebook.com/video/video.php?v=3255866089604
Better it is to make a louder source.
With an array, a transient going in, arrives just like the line array, beginning with the closest source and later ending with the farthest source.
Now lets say you wanted to make 150 dB at 1 meter, at 800 feet, this would be 102.3DB SPL
Rather than a huge pile of those subs, how about just 6 th-812’s?
At LSU, two sets of three in the scoreboard produce all the low end and with music, at the point the limiters are engaging, can hit a measured 105dBa slow (it has to be loud), and is (high passed) -3dB at 27Hz, both at 800 feet.
A weighting means the subs were really cranking as the normal tilt in the lf part (lf rise) is like +15 or more over the rest.
Here are a couple video’s taken while they were setting limiters, if you have headphones that have bass response, you can hear deep bass but picture this being loud, shaking the place.
https://www.dropbox.com/s/va4mihvefqyxk24/20130723140018.mts
https://www.dropbox.com/s/a9uiuvu6pkaojn9/20130723141039.mts
Actually, there are people in Europe using our stuff for EDM in Germany in particular and are planning something for a May festival they have there. I think they high pass the 812’s at 25 over there.
Best,
Tom
Hey just a guy, the volume wasn’t a mistake, the box dimensions (all truck pack, designed to work in a group of 6) and the low corner were picked by the group.
I gave Jerry the driver parameters that would be “perfect” and after a couple rounds, we had a driver that worked pretty well.
There weren’t any drivers that had he mass density back then to do this although the BT-7 driver had 2X15 inch radiators (and much more motor strength and mass).
The whole project came about on PSW when there were many threads about a “wonder sub” and people talking about wanting to build a bunch of W bins.
I thought it would be fun to design a DIY project that would stomp the larger “wonder sub” and show he design process (not sure how much of that is left) but was not a full push design.
That project, now what 12 or 14 years ago has turned into one of Eminences best selling drivers.
Patrick as often he case your Matterhorn sussing is pretty much spot on. The impedance peak around 20Hz, is actually about 22Hz and was where the system was going to sit running 24 hrs a day doing what ever it was. I had to use the first broad impedance peak (operating frequency about 6Hz wide bandwidth) to cut the VC heating.
There is a chance this thing will finally be used at an NFL game next season a half time.
If you have facebook, you might enjoy this video at 11Hz, go full screen and watch his cloths.
https://www.facebook.com/video/video.php?v=3255866089604
Better it is to make a louder source.
With an array, a transient going in, arrives just like the line array, beginning with the closest source and later ending with the farthest source.
Now lets say you wanted to make 150 dB at 1 meter, at 800 feet, this would be 102.3DB SPL
Rather than a huge pile of those subs, how about just 6 th-812’s?
At LSU, two sets of three in the scoreboard produce all the low end and with music, at the point the limiters are engaging, can hit a measured 105dBa slow (it has to be loud), and is (high passed) -3dB at 27Hz, both at 800 feet.
A weighting means the subs were really cranking as the normal tilt in the lf part (lf rise) is like +15 or more over the rest.
Here are a couple video’s taken while they were setting limiters, if you have headphones that have bass response, you can hear deep bass but picture this being loud, shaking the place.
https://www.dropbox.com/s/va4mihvefqyxk24/20130723140018.mts
https://www.dropbox.com/s/a9uiuvu6pkaojn9/20130723141039.mts
Actually, there are people in Europe using our stuff for EDM in Germany in particular and are planning something for a May festival they have there. I think they high pass the 812’s at 25 over there.
Best,
Tom