Wimp!
I've got twelve 12" drivers. (First generation Dayton Titanics.)
Seriously...and I've said this before...beware, if the driver doesn't have a true frequency response graph available, don't buy it. DO NOT accept a T-S simulation plot as a substitute. Ever. The simulations are far, far from the mark. You will not get the deep bass you anticipate if you buy a Shiva/Titanic/et. al. based on T-S simulations. They're 12-15dB down at 30Hz and falling fast.
Take it from one who knows.
Should you buy a driver of this class, you will have to use active EQ to get anything like flat response. This will take a lot of R&D, amp power, money, and time that you might prefer to use in other ways.
I am always sadly amused by those who buy drivers of this nature, then swoon over the soi disant deep bass. Harrumph! Lots of 80Hz does not a subwoofer make! Shows how few people know how to listen.
Don't say you weren't warned.
Grey
I've got twelve 12" drivers. (First generation Dayton Titanics.)
Seriously...and I've said this before...beware, if the driver doesn't have a true frequency response graph available, don't buy it. DO NOT accept a T-S simulation plot as a substitute. Ever. The simulations are far, far from the mark. You will not get the deep bass you anticipate if you buy a Shiva/Titanic/et. al. based on T-S simulations. They're 12-15dB down at 30Hz and falling fast.
Take it from one who knows.
Should you buy a driver of this class, you will have to use active EQ to get anything like flat response. This will take a lot of R&D, amp power, money, and time that you might prefer to use in other ways.
I am always sadly amused by those who buy drivers of this nature, then swoon over the soi disant deep bass. Harrumph! Lots of 80Hz does not a subwoofer make! Shows how few people know how to listen.
Don't say you weren't warned.
Grey
I think you'e right....I just converted my 2 tempests sonos to an IB configuration....and I am scratching my head ..why I didn't do it sooner instead wasted all that time and effort building boxes....IMHO I think for the deepest bass ever you cannot beat an IB....I am planning to add 2 more for a total of 4...I already got a BFD EQ...and a Crest CPX 2600 amp..even tough IB's don't need too much power...Already my present IB...which is in a line array...is trying to destroy the wall their mounted on.....
Greets!
You don't reach the point of diminishing returns until a flea powered (~1 W) amp can drive the system to reference level (115 dB/listening position below 80 Hz). It is assumed that below 20 Hz there will be room gain, so the subs can be less efficient below this point based on it.
Since real explosions, rocket launches, etc., can be above 150 dB, with cannon fire, howitzers, etc., rarefying the air at >194 dB, it's up to you to determine how much your room/home's construction and whoever's watching the movie can handle. FWIW, I busted mine up pretty good with just sustained 16 Hz pipe organ notes at ~live levels in the 120-125 dB range before I even got the chance to set up a HT to see what they could do WFO on special effects, but then it's a stick built post WWII G.I. tract house (aka 'cracker box' around here).
Regardless, if your budget allows for this many subs, then by all means use them if for no other reason than their greater efficiency nets you lower distortion via more dynamic headroom to EQ it flat with less/no electronic boosting.
GM
You don't reach the point of diminishing returns until a flea powered (~1 W) amp can drive the system to reference level (115 dB/listening position below 80 Hz). It is assumed that below 20 Hz there will be room gain, so the subs can be less efficient below this point based on it.
Since real explosions, rocket launches, etc., can be above 150 dB, with cannon fire, howitzers, etc., rarefying the air at >194 dB, it's up to you to determine how much your room/home's construction and whoever's watching the movie can handle. FWIW, I busted mine up pretty good with just sustained 16 Hz pipe organ notes at ~live levels in the 120-125 dB range before I even got the chance to set up a HT to see what they could do WFO on special effects, but then it's a stick built post WWII G.I. tract house (aka 'cracker box' around here).
Regardless, if your budget allows for this many subs, then by all means use them if for no other reason than their greater efficiency nets you lower distortion via more dynamic headroom to EQ it flat with less/no electronic boosting.
GM
Mike,
I usually use one of my Threshold S-500s or an old Hafler 500. I've got plans on the board to give each driver a dedicated amplifier, complete with servo feedback loop, but other projects (Lovoltech circuits, for one thing) keep sneaking in ahead so I haven't gotten that done yet.
Note that active EQ is a killer for amps, demanding prodigious amounts of power in the lower octaves. Mine goes to 16Hz before it tapers off, which is really playing dirty pool. My Hafler, which is the "Pro" version, keeps triggering its protection circuit on serious organ passages. Poor thing.
Class D amps would seem to be a natural for this, but I have yet to hear one that wasn't lean on the low end. I suspect this could be cured with a decent design and a robust enough power supply, but I'd have to build such a beast from the ground up, as none of the commercial units have sufficient power supply for a table radio, much less 500-1000W.
(I could get diverted into a story about playing bass through a Crest amp once upon a time, but will resist the temptation.)
Incidentally, for those who don't believe me when I say the Titanics/Shivas/Tempests/etc. are less than they're advertised to be...go ahead, buy one. If you know how to hear, you'll know you've been swindled the first time you listen. Otherwise, measure it. If you accept ahead of time that you're going to have to use EQ to get decent response, you won't be so bad off. I had to learn the hard way.
Grey
I usually use one of my Threshold S-500s or an old Hafler 500. I've got plans on the board to give each driver a dedicated amplifier, complete with servo feedback loop, but other projects (Lovoltech circuits, for one thing) keep sneaking in ahead so I haven't gotten that done yet.
Note that active EQ is a killer for amps, demanding prodigious amounts of power in the lower octaves. Mine goes to 16Hz before it tapers off, which is really playing dirty pool. My Hafler, which is the "Pro" version, keeps triggering its protection circuit on serious organ passages. Poor thing.
Class D amps would seem to be a natural for this, but I have yet to hear one that wasn't lean on the low end. I suspect this could be cured with a decent design and a robust enough power supply, but I'd have to build such a beast from the ground up, as none of the commercial units have sufficient power supply for a table radio, much less 500-1000W.
(I could get diverted into a story about playing bass through a Crest amp once upon a time, but will resist the temptation.)
Incidentally, for those who don't believe me when I say the Titanics/Shivas/Tempests/etc. are less than they're advertised to be...go ahead, buy one. If you know how to hear, you'll know you've been swindled the first time you listen. Otherwise, measure it. If you accept ahead of time that you're going to have to use EQ to get decent response, you won't be so bad off. I had to learn the hard way.
Grey
well yall are probably going to laugh at me but i am going to be running car subs.... i have limited resources so i am going with what i can get .... i have 1 mtx sw12 and 2 6500 series 12's in boxes built into my couch powered by a jbl car am at 200 x 2 rms
.... and 1 am plannin on getting 6 more subs that i will put into a coffee table and 2 end tables which will be run by a xls602b crown amp rated at 1680 watts at 4ohms bridged .... will this be too much
.... and 1 am plannin on getting 6 more subs that i will put into a coffee table and 2 end tables which will be run by a xls602b crown amp rated at 1680 watts at 4ohms bridged .... will this be too much
scottr0,
Expect to use a lot of EQ if you want anything like flat response. Otherwise you'll end up with a great deal of 80-100Hz and not much below. That may or may not be enough to float your boat.
The drivers I mentioned above are basically car woofers with other names attached to them. Everything I said still applies.
I'm not clear why you keep asking if it's too much. If the intent is to get me to say,"Wow, what a huge system!" it's not working. If the intent is to get suggestions as to how to save money, I'd suggest not doing it at all--spend a little more time doing homework, then go for flat drivers, not car drivers (or, by extension, Titanics/Shivas/etc.). It doesn't sound as though you're up for doing the EQ thing. You'll probably find that'll you'll save money in the long run. If you're asking about the amplifiers or wattage, my response is to ask if you've got sufficient power supply ready for the car amp. Other than that, power is fine.
What, exactly, are you seeking?
micb,
Sealed boxes, six drivers per side in 7' tall cabinets. My room is something on the order of 13'x21'...I don't remember the exact dimensions offhand.
RobWells,
Thanks. A picture being worth a thousand words and all that...your frequency response graph isn't too far different from what I see here with the Titanics. The dip at 70Hz (I think, the nomenclature on the graph is hard to read) is much less in my room. The dip ca. 35Hz is more like 45-50 and not as deep. The peak at 100Hz is a little less pronounced. Given that, if you "smooth" the graph, you'll see pretty much the same 6dB/oct falling response I get. My solution was a 6dB/oct LP at 15.9Hz, which flattened things considerably, leading to the actual crossover point at a little over 70Hz. All these drivers have pretty much the same general response curve, so a similar EQ circuit would probably work decently.
Another possibility, at least with that Tempest graph, would be a notch filter at 50Hz and another at 100Hz, then treat what remains as flat and go from there.
Grey
Expect to use a lot of EQ if you want anything like flat response. Otherwise you'll end up with a great deal of 80-100Hz and not much below. That may or may not be enough to float your boat.
The drivers I mentioned above are basically car woofers with other names attached to them. Everything I said still applies.
I'm not clear why you keep asking if it's too much. If the intent is to get me to say,"Wow, what a huge system!" it's not working. If the intent is to get suggestions as to how to save money, I'd suggest not doing it at all--spend a little more time doing homework, then go for flat drivers, not car drivers (or, by extension, Titanics/Shivas/etc.). It doesn't sound as though you're up for doing the EQ thing. You'll probably find that'll you'll save money in the long run. If you're asking about the amplifiers or wattage, my response is to ask if you've got sufficient power supply ready for the car amp. Other than that, power is fine.
What, exactly, are you seeking?
micb,
Sealed boxes, six drivers per side in 7' tall cabinets. My room is something on the order of 13'x21'...I don't remember the exact dimensions offhand.
RobWells,
Thanks. A picture being worth a thousand words and all that...your frequency response graph isn't too far different from what I see here with the Titanics. The dip at 70Hz (I think, the nomenclature on the graph is hard to read) is much less in my room. The dip ca. 35Hz is more like 45-50 and not as deep. The peak at 100Hz is a little less pronounced. Given that, if you "smooth" the graph, you'll see pretty much the same 6dB/oct falling response I get. My solution was a 6dB/oct LP at 15.9Hz, which flattened things considerably, leading to the actual crossover point at a little over 70Hz. All these drivers have pretty much the same general response curve, so a similar EQ circuit would probably work decently.
Another possibility, at least with that Tempest graph, would be a notch filter at 50Hz and another at 100Hz, then treat what remains as flat and go from there.
Grey
Hi Grey,
Yes I used a behringer feedback destroyer to eq the 2 big peaks at 50Hz and 100Hz. The peak just above 100Hz is 13 / 14dB higher than the 20Hz reading.
What is interesting is that room gain makes them flat ~15Hz - 30Hz.
I've still got 4 tempests but no longer use them. I'm saving them for when I get a bigger room and need lots of 15's.
Cheers,
Rob.
Yes I used a behringer feedback destroyer to eq the 2 big peaks at 50Hz and 100Hz. The peak just above 100Hz is 13 / 14dB higher than the 20Hz reading.
What is interesting is that room gain makes them flat ~15Hz - 30Hz.
I've still got 4 tempests but no longer use them. I'm saving them for when I get a bigger room and need lots of 15's.
Cheers,
Rob.
There's a very good reason to use so much sub, that I'm surprised nobody has mentioned:
The room! Did we all forget? Lots of subs all around the room gives you more than just a lot of displacement and more reasonable distortion, it breaks up modal and nodal effects of the room, giving better consistency and linearity!
The room! Did we all forget? Lots of subs all around the room gives you more than just a lot of displacement and more reasonable distortion, it breaks up modal and nodal effects of the room, giving better consistency and linearity!
GRollins:
How many cubic foot do you have per shiva driver?
Do you have them in a low Q alignment as the required enclosure would be massive?
Is this partially why you are having to EQ the low end becuase of enclosure restrictions?
For a medium Q of 0.7 you would need 648 liters net before driver displacement this is approx 22 cubes and do low Q alignment 0.57-0.5 Q you are looking at 1200-2100 liters or 42 to 120 cubes +.
How many cubic foot do you have per shiva driver?
Do you have them in a low Q alignment as the required enclosure would be massive?
Is this partially why you are having to EQ the low end becuase of enclosure restrictions?
For a medium Q of 0.7 you would need 648 liters net before driver displacement this is approx 22 cubes and do low Q alignment 0.57-0.5 Q you are looking at 1200-2100 liters or 42 to 120 cubes +.
As I believe I said earlier, I've got Titanics, not Shivas, not that there's really a significant difference in performance.
The cabinets are about 15" across the front , but deep. I don't recall the exact dimensions. Techincally they are .707, but from the performance you'd expect a high Q, in that there's a peak before the rolloff (see graph in RobWells's post and my commentary in subsequent post)--or--low Q, in that there's a slower-than-12dB rolloff. Take your pick.
Once I found out what I was dealing with, I just EQed the stupid things and went on to other projects. It's annoying, but not the end of the world. However, I'd rather be playing with amps, preamps, etc. and I resent not being told (via honest graphs/specs) what I was getting myself into. I pity those who buy such a pig in a poke and do not have the resources to attack the problem.
Even more, I pity those who think un-EQed drivers of this sort are how bass is supposed to sound, but at least that is subject to education once you get past the inevitable "Of course my subs are flat down to 20Hz...the Thiele-Small simulations say so!"
Anyone who owns drivers like this and feels disposed to argue should measure before posting. You'll find that you've got something similar to the graph that RobWells posted...clearly these drivers are far from flat. My response is somewhat less jagged than his, but clearly cut from the same cloth.
You have been warned. Proceed at your own risk. Buyer beware. Etc.
Grey
The cabinets are about 15" across the front , but deep. I don't recall the exact dimensions. Techincally they are .707, but from the performance you'd expect a high Q, in that there's a peak before the rolloff (see graph in RobWells's post and my commentary in subsequent post)--or--low Q, in that there's a slower-than-12dB rolloff. Take your pick.
Once I found out what I was dealing with, I just EQed the stupid things and went on to other projects. It's annoying, but not the end of the world. However, I'd rather be playing with amps, preamps, etc. and I resent not being told (via honest graphs/specs) what I was getting myself into. I pity those who buy such a pig in a poke and do not have the resources to attack the problem.
Even more, I pity those who think un-EQed drivers of this sort are how bass is supposed to sound, but at least that is subject to education once you get past the inevitable "Of course my subs are flat down to 20Hz...the Thiele-Small simulations say so!"
Anyone who owns drivers like this and feels disposed to argue should measure before posting. You'll find that you've got something similar to the graph that RobWells posted...clearly these drivers are far from flat. My response is somewhat less jagged than his, but clearly cut from the same cloth.
You have been warned. Proceed at your own risk. Buyer beware. Etc.
Grey
I'd agree with you about simlations often differ to real world performance but there are plenty out there who do have very flat playing systems.
It is fairly obvious now, the reason the drivers are performing like a car drivers do is even though you have loads of potential displacement you enclosure is the limit.
If you removed some drivers your overall SPL would drop a few DB but your enclosure peak and in room F3 would also drop.
A much larger sealed or low tuned ported would most likely elivate the need for such EQ at 35hz and below.
It is fairly obvious now, the reason the drivers are performing like a car drivers do is even though you have loads of potential displacement you enclosure is the limit.
If you removed some drivers your overall SPL would drop a few DB but your enclosure peak and in room F3 would also drop.
A much larger sealed or low tuned ported would most likely elivate the need for such EQ at 35hz and below.
Oh, so this is going to turn into one of those threads...
Over on the electronics side of things, there are simulation programs too. The people who use them are generally aware (even if only dimly) that reality and theory don't always match up. For proof, go read the first ten or twenty pages of my Aleph-X thread, wherein I posted the schematic for the amp, then had to endure a barrage of posts telling me it wouldn't work. But--like Yoda, whose ally is the Force--I had something on my side called Reality. You see, I wasn't posting a schematic I'd worked up in a simulator, it was the schematic of a real, working amplifier; an actual prototype. So no matter how strident the complaints and criticisms, I was secure because Reality was my ally.
My motto became: Reality beats theory seven days a week.
People who build speakers do not seem to be as aware of the failings of their simulations. They build speakers based on their simulations and assume that the pretty line on the computer screen is what they're getting in their living room, because of their blind faith that Thiele-Small covers everything. Never mind that cone breakup and cabinet resonances, just to name two factors, never enter into the equation.
As for the specific criticisms posted above, I'd suggest a review of basic math. The last time I checked, 3<12, yet RobWells posted a nearly identical response graph to what I got. So, clearly it isn't a question of reducing the number of drivers--something that should have been obvious, anyway. Nor is it a question of cabinetry, as every single real graph of these drivers I've ever seen (as opposed to T-S simulations) all show roughly the same thing.
There are no speakers that go to 20Hz flat without EQ, only people who delude themselves that what they're hearing is honest, deep bass. There are two cures for this delusion:
1) Spend time listening to real, unamplified music. In other words, educate your ears. The failings of these drivers are obvious on first listen; I knew something was amiss the first time I turned them on. It was obvious that they weren't flat. Unfortunately, too many people have come to accept concert hall PA systems or dance club boom-boom (worse yet, car stereo boom-boom) as their reference. Pathetic.
2) Borrow or buy some test equipment. I borrowed some stuff once I knew I had a problem. Unfortunately, my source has since dried up so I'll have to buy something the next time I go through the R&D process.
Either method will lead you to the same conclusion--these drivers are seriously flawed. If you go in with the understanding that there are going to be problems, you'll be okay, but to approach the project in blind faith that the simulations are anywhere near correct is foolhardy.
Grey
Over on the electronics side of things, there are simulation programs too. The people who use them are generally aware (even if only dimly) that reality and theory don't always match up. For proof, go read the first ten or twenty pages of my Aleph-X thread, wherein I posted the schematic for the amp, then had to endure a barrage of posts telling me it wouldn't work. But--like Yoda, whose ally is the Force--I had something on my side called Reality. You see, I wasn't posting a schematic I'd worked up in a simulator, it was the schematic of a real, working amplifier; an actual prototype. So no matter how strident the complaints and criticisms, I was secure because Reality was my ally.
My motto became: Reality beats theory seven days a week.
People who build speakers do not seem to be as aware of the failings of their simulations. They build speakers based on their simulations and assume that the pretty line on the computer screen is what they're getting in their living room, because of their blind faith that Thiele-Small covers everything. Never mind that cone breakup and cabinet resonances, just to name two factors, never enter into the equation.
As for the specific criticisms posted above, I'd suggest a review of basic math. The last time I checked, 3<12, yet RobWells posted a nearly identical response graph to what I got. So, clearly it isn't a question of reducing the number of drivers--something that should have been obvious, anyway. Nor is it a question of cabinetry, as every single real graph of these drivers I've ever seen (as opposed to T-S simulations) all show roughly the same thing.
There are no speakers that go to 20Hz flat without EQ, only people who delude themselves that what they're hearing is honest, deep bass. There are two cures for this delusion:
1) Spend time listening to real, unamplified music. In other words, educate your ears. The failings of these drivers are obvious on first listen; I knew something was amiss the first time I turned them on. It was obvious that they weren't flat. Unfortunately, too many people have come to accept concert hall PA systems or dance club boom-boom (worse yet, car stereo boom-boom) as their reference. Pathetic.
2) Borrow or buy some test equipment. I borrowed some stuff once I knew I had a problem. Unfortunately, my source has since dried up so I'll have to buy something the next time I go through the R&D process.
Either method will lead you to the same conclusion--these drivers are seriously flawed. If you go in with the understanding that there are going to be problems, you'll be okay, but to approach the project in blind faith that the simulations are anywhere near correct is foolhardy.
Grey
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