3x12+2"wNL8's&4Xti4000's

Re: 3x12+2"wNL8's&4Xti4000's

Tim McCulloch said:
How does it sound off axis, say 30° or so to either side and up/down?
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They sound even and consistent to my ears. We need some more ears in the Tampa Bay area to testify - can I get a witness?! There is not much up or down to these because they are outside on a flat area and they stand pretty tall when placed on top of the subs.
 
Re: 3x12+2"wNL8's&4Xti4000's

Gene Hardage said:

That's roughly 2000 watts per cab with no caps or iron in the way causing issues - :[/FONT]
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I would NOT (edit) automatically say that cap or coils "cause issues". It is not the components-but how they are used. As with any other tool-if you use it wrong-the results will not be as good as they could be-if used properly.

Of course there are advantages and disadvantages to different design approaches. For example-if all of your processing is inside your amps-and an amp goes bad-you cannot just stick another amp (that may be lying around) on that particular speaker. Just sayin'--------------
 
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Re: 3x12+2"wNL8's&4Xti4000's

Ivan Beaver said:
I would automatically say that cap or coils "cause issues". It is not the components-but how they are used. As with any other tool-if you use it wrong-the results will not be as good as they could be-if used properly.

Of course there are advantages and disadvantages to different design approaches. For example-if all of your processing is inside your amps-and an amp goes bad-you cannot just stick another amp (that may be lying around) on that particular speaker. Just sayin'--------------
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The further into software based sound we get the more complex every little thing becomes. I agree that this design has a few things to worry about - like - what if 1 or more amps act up then what? You can't hook just anything up to them because they have only NL8's. As we speak I am coming up with a failsafe workaround should that happen. My subs are run on 2 Crown Xti6002 amps and they will be in a single 4 space rack. I intend to program them with presets that will allow me to run the tops mono from a single NL8 jack if I have to. Of course that would limit me to a total of 4 top cabs but it would be enough to get me through a gig if I had to. Then I would have to scrounge around and find a working amp to mono bridge to get some sub action.
 
Re: 3x12+2"wNL8's&4Xti4000's

Regarding my caps and iron comment - the premise is that amps see caps and coils as they operate and the load they create reacts with the signal. My theory is that it is a more direct signal path without the caps or coils. Hopefully this will result in a cleaner more responsive speaker.
 
Re: 3x12+2"wNL8's&4Xti4000's

Gene Hardage said:
Regarding my caps and iron comment - the premise is that amps see caps and coils as they operate and the load they create reacts with the signal. My theory is that it is a more direct signal path without the caps or coils. Hopefully this will result in a cleaner more responsive speaker.
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My post was in error-and I left out the NOT in the first sentance (I would NOT automatically assume----------)

In what way do you think that the amps "see" the signal and how do they "react" to them? Unless the load is highly inductive or capacitive (which most loudspeakers are not) the amp "should not care".

If caps and coils were so 'bad sounding", then how come historically a large majority of the "best sounding" speakers have been passive?

Passive has it place-as does active. But a lot of people "automatically" assume that active is better than passive. I would argue that either is bad-if poorly done. Properly done-they each can work well (depending on the design limitations of the design (such as signal arrival (time of flight) of the various passbands).
 
Re: 3x12+2"wNL8's&4Xti4000's

Ivan Beaver said:
My post was in error-and I left out the NOT in the first sentance (I would NOT automatically assume----------)

In what way do you think that the amps "see" the signal and how do they "react" to them? Unless the load is highly inductive or capacitive (which most loudspeakers are not) the amp "should not care".

If caps and coils were so 'bad sounding", then how come historically a large majority of the "best sounding" speakers have been passive?

Passive has it place-as does active. But a lot of people "automatically" assume that active is better than passive. I would argue that either is bad-if poorly done. Properly done-they each can work well (depending on the design limitations of the design (such as signal arrival (time of flight) of the various passbands).
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I'm certainly no expert and most of my opinions are just that - opinions. However it's generally agreed that amp power is wasted on caps and coils and that the bigger higher powered speakers usually get crossed over using electronic crossovers. As for the amp "seeing them" it's just another opinion based on how amps react to different speaker loads - wire length and gauge etc. Now we have even more advanced things like System Architect and Lake (sp?) that have some pretty spiffy bells and whistles. Silas mentioned "FIR linear-phase crossover" and I think that's what was done with this box. Whatever it is - it really sounds nice. It's a lot like that smaller 4x10+1" column that I got a while back that has a fancy passive crossover in it. I need some witnesses down here in the Tampa area - bring yer smart stuff and measure these rascals.
 
Re: 3x12+2"wNL8's&4Xti4000's

Gene Hardage said:
I'm certainly no expert and most of my opinions are just that - opinions. However it's generally agreed that amp power is wasted on caps and coils and that the bigger higher powered speakers usually get crossed over using electronic crossovers. .
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I am not arguing about your loudspeakers-All I am trying to do is to "clear up" some misconceptions about passive crossovers.

If using decent quality parts-there is no appreciable loss through the part-EXCEPT for the freq that the cap or coil is trying to filter out anyway. Within the intended passband-you will never know that the part is even in the circuit.

Regarding large speakers-yes you have to use large passive parts (because of the higher voltage and current). But in MANY cases- you cannot do a proper passive crossover-because the "time of flight" from the various devices is so far off-you have to have delay to attempt to line them up (even if only at a single point in the listening plane-other places will need different delays-so you have to choose one point and "live with it").

While you can get a little bit of "correction" by using the phase shift associated with caps and coils-they are limited. So if the cabinet is physically "out of whack", you have to resort to an active alignment.

Just don't automatically say that "the use of caps and coils" is bad-it is only bad-when used improperly. Just like an active setup.

The nice thing about a passive setup-is that it is pretty hard for the user to "screw it up". Just plug it in and go. With an active setup-if an amp goes down and you replace it with an amp that has a different gain-the sound is going to be out fo balance. Of if somebody messes with the crossover freq-or delay time etc etc.

There is no "perfect" setup-only perfect for a particualr situation.
 
Re: 3x12+2"wNL8's&4Xti4000's

Ivan Beaver said:
I am not arguing about your loudspeakers-All I am trying to do is to "clear up" some misconceptions about passive crossovers.

If using decent quality parts-there is no appreciable loss through the part-EXCEPT for the freq that the cap or coil is trying to filter out anyway. Within the intended passband-you will never know that the part is even in the circuit.

Regarding large speakers-yes you have to use large passive parts (because of the higher voltage and current). But in MANY cases- you cannot do a proper passive crossover-because the "time of flight" from the various devices is so far off-you have to have delay to attempt to line them up (even if only at a single point in the listening plane-other places will need different delays-so you have to choose one point and "live with it").

While you can get a little bit of "correction" by using the phase shift associated with caps and coils-they are limited. So if the cabinet is physically "out of whack", you have to resort to an active alignment.

Just don't automatically say that "the use of caps and coils" is bad-it is only bad-when used improperly. Just like an active setup.

The nice thing about a passive setup-is that it is pretty hard for the user to "screw it up". Just plug it in and go. With an active setup-if an amp goes down and you replace it with an amp that has a different gain-the sound is going to be out fo balance. Of if somebody messes with the crossover freq-or delay time etc etc.

There is no "perfect" setup-only perfect for a particualr situation.
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A little help here from the forum please - help educate me on this point. Ivan's opinion is stated in bold above and mine is the more or less knit-picky opposite. I've always heard that passive crossovers in cabs chew up power and that was the rationale for everyone going with the typical electronic crossovers of yesteryear. Taking this point a step further I also contend that amps "see" whatever load they are given and that caps and coils are part of what an amp "sees" as a load. Therefore a modern system using software based processing ala System Architect - Lake - Driverack - etc. will allow the amp to function more efficiently. So - am I losing my knit-picky mind or on the right track here?
 
Re: 3x12+2"wNL8's&4Xti4000's

Gene,

Passive crossovers don't have to chew up power, just some of them do. If you're passively trying to pad down 8dB of efficiency out of your HF horn to match your LF woofer, then that power has to get turned into heat by a resistor. If there is inline equalization available, or if you're clever with the impedance of your components, there may not need to be any resistive padding at all.
 
Re: 3x12+2"wNL8's&4Xti4000's

Bennett Prescott said:
Gene,

Passive crossovers don't have to chew up power, just some of them do. If you're passively trying to pad down 8dB of efficiency out of your HF horn to match your LF woofer, then that power has to get turned into heat by a resistor. If there is inline equalization available, or if you're clever with the impedance of your components, there may not need to be any resistive padding at all.
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OK that sounds familiar and reasonable. Any opinions on the amps "seeing" whatever kind of load they are given - speaker - cap and coil - wire length etc. Help me with my OCD.
 
Re: 3x12+2"wNL8's&4Xti4000's

Gene Hardage said:



A little help here from the forum please - help educate me on this point. Ivan's opinion is stated in bold above and mine is the more or less knit-picky opposite. I've always heard that passive crossovers in cabs chew up power and that was the rationale for everyone going with the typical electronic crossovers of yesteryear. Taking this point a step further I also contend that amps "see" whatever load they are given and that caps and coils are part of what an amp "sees" as a load. Therefore a modern system using software based processing ala System Architect - Lake - Driverack - etc. will allow the amp to function more efficiently. So - am I losing my knit-picky mind or on the right track here?
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If you have a "problem" with caps and coils-you better not hook up a loudspeaker to an amp. All loudspeaker are mostly inductive (coils) and also have a capacitive component. Along with the resistive element of the wire itself in the voice COIL. It is called that for a reason.

Historically passive crossovers have gotten a bad rap. Kinda a lot like Peavey equipment. It is not so much the gear itself-but how it is used that makes the difference.

In "days of old" large coils and decent value high voltage capacitors were very hard to come by (caps more than the coils). So people used what was available. And the typical way of "designing" a crossover was to go cheap in the design-and therefore the result was not as good as it could have been.

It is not so much that passive crossover "chew up power", but you can get more SPL out of a box by using more (2 or 3 typically) smaller amplifiers-if the total "wattage" is the same.

For example if you have a 1500 watt amp into a passive crossover, a 1000 watt and a 500 watt may be a little bit louder.

HOWEVER if you use a large amp on the passive (which you can-because the passive crossover is "dividing" the power-along with the freq) so not all the 1500 watts is going to a single driver.

So with the larger amp-the same (1000 watts) would be going to the driver.

You ALSO have to forget the whole "wattage" thing. It all needs to be divided into VOLTAGE and impedance. Watts is a VERY loose term-that people get to hung up on. Thinking in terms of voltage per device is a lot better way of looking at things.

This difference is also not huge. But passive crossovers have gotten a bad rap-because typically only the cheaper cabinets have used them-and the sound that comes from those cabinets is not always optimal.

Kinda like the whole "line array vs point source thing". First of all there are VERY few boxes that should be called "point sources". Most of the so called "point sources" ARE NOT-they are simply speakers stuck in a box-and since they are not "line arrays" they get the "other" name.

In years past (before prediction software and DSP's and measurement platforms (except TEF and very few others) the way to get louder was to simple pile up more boxes. This resulted in lots of interference and the sound quality suffered.

Along comes the line array-at about the same time as easily accessable measurement software-the internet and the huge sharing of knowlege-that we all have benifited from.

So line array designers actually started DESIGNING the cabnets so as to minimize the interactions-not only in the individual cabinet-but also in multiple cabinets (not just throwing drivers into cabinets). So the result is better real engineering.

So the old "point source" boxes (with all kinds of interaction-not only within the box-but also greatly between boxes) are compared to the new "line arrays", which have better engineering.

But when you start to compare a cabinet that is close to a real point source (due to modern design/engineering)-to the interaction of the line array-things start to sound different.

So you just have to be careful when comparing designs of old vs new designs.

Ad this carries on to other industries-such as car racing. In years past who thought the winner would be driving a diesal engine? Don't tell that to some of the road track winners. Diesals are only good for pulling heavy loads-thats why they are used in trucks------------Not exaclty.

Technology has changed a lot of things.

Old wives tales are not always relivant to todays situations.

Getting off the soap box now----------------
 
Re: 3x12+2"wNL8's&4Xti4000's

Bennett Prescott said:
Gene,

Passive crossovers don't have to chew up power, just some of them do. If you're passively trying to pad down 8dB of efficiency out of your HF horn to match your LF woofer, then that power has to get turned into heat by a resistor. If there is inline equalization available, or if you're clever with the impedance of your components, there may not need to be any resistive padding at all.
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Yes you do have to "get rid" of that voltage going to the HF device-because the HF device has a much greater sensitivity (and lower "power" capacity) than the woofer.

If you do it "up stream" via EQ (which is one way to do it), you have to assume that the user will do it properly- and not screw it up. Remember we are talking aobut sounds guys here whom many just HAVE to pee on the tires-to make it "better"-because THEY did it. I don't want to get started on that one.

The impedance one can be quite a bit tricky. At first glance it would seem simple enough to just use a higher impedance HF device-so that for a given input voltage the current flow would be less and therefore there would be less sound coming out of it. So far so good.

HOWEVER we have to look at bit closer at what REALLY happens-especially when you put a driver on a horn.

One of the big "unknowns/misconceptions/unspoken etc" is that simply putting a driver (compression driver-midrange-woofer etc) on a horn will make it louder. Yes it will-BUT it is not an flat "gain" across the freq range.

Let's look at just the HF (the mids and lows work the same way). Let's say a HF driver has a flat response (most are not-but let's assume so for this example). When you put the driver on a horn, you will get a hump in the response. On the top end of the response-the horn is doing little to nothing in the way of horn gain. All of the available "gain" has already happened-BEFORE the sound gets out of the HF driver. All the horn does is to control the pattern (which can result in gain-over a driver that is not on a horn). The point at which this happens is determined by the size of the driver opening (or cone diameter for lower freq). The larger the opening-the lower the point at which the horn will actually have any gain. This is part of the reason that drivers with 2" exits don't have a lot of HF (among other reasons)

So at the point at which the horn has gain-down to the point at which the exit size of the horn is not large enough-or the driver response starts to fall off-or a combination of both-the sound from the driver/horn combination will be louder.

So now we have a problem. The top end of the response is lower than the "midband" response. If we use a higher impedance driver to drop this "midband gain", then the top end is ALSO going to drop (by the same amount. So now the higher freq may not be as loud as the woofer-especially when given the reduced input signal level.

So a good passive crossover will "throw away" the extra gain of horn down low (resulting in some heat) by effectively putting a freq dependant series resistor (via the caps and coils) in line with the HF driver.

So at the top end of the response-then there is no attenuation through the crossver. So the resultant freq output is flat.

There are different ways to "skin a cat". It just depends on whether you want to do it inside the cabinet (via passive crossover or an active cabinet) where the user can't easily screw it up, or externally (bi/tri amping or eq in line with a passive "divider" inside the cabinet) in which the manufacturer HOPES that the end user doesn't try to "roll their own" design and screw up something that they don't understand.

There are advantages and disadvantages to every design-and compromises that have to be made all along the way.

As with all things-you have to look at more than one anlge to get the full "picture". That whole -simple, easy to understand wrong answer, thing.
 
Re: 3x12+2"wNL8's&4Xti4000's

Ivan Beaver said:
Yes you do have to "get rid" of that voltage going to the HF device-because the HF device has a much greater sensitivity (and lower "power" capacity) than the woofer.

If you do it "up stream" via EQ (which is one way to do it), you have to assume that the user will do it properly- and not screw it up. Remember we are talking aobut sounds guys here whom many just HAVE to pee on the tires-to make it "better"-because THEY did it. I don't want to get started on that one.

The impedance one can be quite a bit tricky. At first glance it would seem simple enough to just use a higher impedance HF device-so that for a given input voltage the current flow would be less and therefore there would be less sound coming out of it. So far so good.

HOWEVER we have to look at bit closer at what REALLY happens-especially when you put a driver on a horn.

One of the big "unknowns/misconceptions/unspoken etc" is that simply putting a driver (compression driver-midrange-woofer etc) on a horn will make it louder. Yes it will-BUT it is not an flat "gain" across the freq range.

Let's look at just the HF (the mids and lows work the same way). Let's say a HF driver has a flat response (most are not-but let's assume so for this example). When you put the driver on a horn, you will get a hump in the response. On the top end of the response-the horn is doing little to nothing in the way of horn gain. All of the available "gain" has already happened-BEFORE the sound gets out of the HF driver. All the horn does is to control the pattern (which can result in gain-over a driver that is not on a horn). The point at which this happens is determined by the size of the driver opening (or cone diameter for lower freq). The larger the opening-the lower the point at which the horn will actually have any gain. This is part of the reason that drivers with 2" exits don't have a lot of HF (among other reasons)

So at the point at which the horn has gain-down to the point at which the exit size of the horn is not large enough-or the driver response starts to fall off-or a combination of both-the sound from the driver/horn combination will be louder.

So now we have a problem. The top end of the response is lower than the "midband" response. If we use a higher impedance driver to drop this "midband gain", then the top end is ALSO going to drop (by the same amount. So now the higher freq may not be as loud as the woofer-especially when given the reduced input signal level.

So a good passive crossover will "throw away" the extra gain of horn down low (resulting in some heat) by effectively putting a freq dependant series resistor (via the caps and coils) in line with the HF driver.

So at the top end of the response-then there is no attenuation through the crossver. So the resultant freq output is flat.

There are different ways to "skin a cat". It just depends on whether you want to do it inside the cabinet (via passive crossover or an active cabinet) where the user can't easily screw it up, or externally (bi/tri amping or eq in line with a passive "divider" inside the cabinet) in which the manufacturer HOPES that the end user doesn't try to "roll their own" design and screw up something that they don't understand.

There are advantages and disadvantages to every design-and compromises that have to be made all along the way.

As with all things-you have to look at more than one anlge to get the full "picture". That whole -simple, easy to understand wrong answer, thing.
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I've enjoyed this post quite a bit and have read through it a couple of times trying to find the part I'm looking for. Yes a properly designed passive crossover with quality caps and coils and maybe a varistor for good luck is a true work of art and I'm familiar with scooping the lower end of a horn driver's response to make up for the way they often drop on the high end. What I'm hoping for in this case is a clearer signal path with fewer anomalies created by those pesky passive components. I've made my own coolaid and I'm passing some around to see if anyone else likes the idea. :lol:
 
Re: 3x12+2"wNL8's&4Xti4000's

Gene Hardage said:
I've enjoyed this post quite a bit and have read through it a couple of times trying to find the part I'm looking for. Yes a properly designed passive crossover with quality caps and coils and maybe a varistor for good luck is a true work of art and I'm familiar with scooping the lower end of a horn driver's response to make up for the way they often drop on the high end. What I'm hoping for in this case is a clearer signal path with fewer anomalies created by those pesky passive components. I've made my own coolaid and I'm passing some around to see if anyone else likes the idea. :lol:
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One thing that would be interesting would be some measurements-in different parts of the coverage pattern-particularly in the vertical-thats where the alignment will show how good it is.
 
Re: 3x12+2"wNL8's&4Xti4000's

Ivan Beaver said:
One thing that would be interesting would be some measurements-in different parts of the coverage pattern-particularly in the vertical-thats where the alignment will show how good it is.
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Does anyone have a "Smart" friend in the Tampa area with the proper tools to measure with? I'll have the whole rig set up outside this Saturday.
 
Re: 3x12+2"wNL8's&4Xti4000's

Gene Hardage said:
Does anyone have a "Smart" friend in the Tampa area with the proper tools to measure with? I'll have the whole rig set up outside this Saturday.
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Do you have any measurements that were taken during the DSP settings "session"-or how the settings were "arrived at". Granted that would be only on axis (I assume) and not multiple positions-but would be a start.

Be sure to look at the phase traces also when doing measurements.

It would be good to look at just a single box-and also multiples-with the same setup. That way you can get a better idea of what is really happening.

The ear can be easily "fooled"_ I know mine has been-many times. That is why we need measurements-to confirm if we really are hearing something-or what may be causing it.
 
Re: 3x12+2"wNL8's&4Xti4000's

Ivan Beaver said:
Do you have any measurements that were taken during the DSP settings "session"-or how the settings were "arrived at". Granted that would be only on axis (I assume) and not multiple positions-but would be a start.

Be sure to look at the phase traces also when doing measurements.

It would be good to look at just a single box-and also multiples-with the same setup. That way you can get a better idea of what is really happening.

The ear can be easily "fooled"_ I know mine has been-many times. That is why we need measurements-to confirm if we really are hearing something-or what may be causing it.
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Sorry I have nothing to show you. They have an older piece of gear that has a pink noise generator, little lights, and a measurement mic. He adjusted the System Architect program on each amp using that device. Yes it was just a single speaker on axis and like you I would love to know how well they play together when coupled. I'll be posting this on a local sound forum hoping for someone to step up with modern measuring tools and a way to document it for all to see. Anyone in my area this Saturday is welcome to give it shot.
 
Re: 3x12+2"wNL8's&4Xti4000's

Gene Hardage said:
Sorry I have nothing to show you. They have an older piece of gear that has a pink noise generator, little lights, and a measurement mic. He adjusted the System Architect program on each amp using that device. Yes it was just a single speaker on axis and like you I would love to know how well they play together when coupled. I'll be posting this on a local sound forum hoping for someone to step up with modern measuring tools and a way to document it for all to see. Anyone in my area this Saturday is welcome to give it shot.
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Was he using an RTA or something that he could see the phase display? Were the "little lights" vertical rows of LED's for each freq?

And was he looking at the phase display? or just amplitude?
 
Re: 3x12+2"wNL8's&4Xti4000's

Ivan Beaver said:
Was he using an RTA or something that he could see the phase display? Were the "little lights" vertical rows of LED's for each freq?

And was he looking at the phase display? or just amplitude?
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The little lights were vertical rows of red LED's for each frequency. It's a box with the display on the front along with a mic input and a pink noise generator. Don't know about the phase display or if it does that or what that is.
 
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