So can a 15" driver really do it all?
Well, I have gotten intrigued by the single drivers made by Common Sense Audio. I just ordered the 15" pair after some correspondence with the owner.
Driver Specs
I figured that I would try them out in a rough open baffle from his designs. It will be easy and inexpensive to build. If I like what I hear, I'll figure out what box to build later.
Since he has a good return guarantee, I feel good about trying it out as a first project.
I currently have a Horning Hybrid speaker with a modified Lowther driver running without crossover and a paper tweeter on the highs. So I am very familiar with full range or at least very wide range. I have heard many of the full range speakers at various shows in the last five years. My favorite of those are the Maxxhorns.
I definitely have my doubts about the intermodulation distortion (it that's the right term) that can happen with bass frequencies playing from the same driver as highs.
I know that many of the single driver systems - Lowthers, Fostex, Feastrex etc. can sound rough when pushed with complex music.
I have heard the Feastrex three times. I thought they sounded ok, but they didn't do so well with complex music or volume.
What I expect to figure out with the open baffle is if I am hearing these kind of problems including garbling, roughness on peaks, coherence, treble smoothness etc. At least down to the 60hz or so that an open baffle can do.
Any suggestions or ideas about these drivers?
Well, I have gotten intrigued by the single drivers made by Common Sense Audio. I just ordered the 15" pair after some correspondence with the owner.
Driver Specs
I figured that I would try them out in a rough open baffle from his designs. It will be easy and inexpensive to build. If I like what I hear, I'll figure out what box to build later.
Since he has a good return guarantee, I feel good about trying it out as a first project.
I currently have a Horning Hybrid speaker with a modified Lowther driver running without crossover and a paper tweeter on the highs. So I am very familiar with full range or at least very wide range. I have heard many of the full range speakers at various shows in the last five years. My favorite of those are the Maxxhorns.
I definitely have my doubts about the intermodulation distortion (it that's the right term) that can happen with bass frequencies playing from the same driver as highs.
I know that many of the single driver systems - Lowthers, Fostex, Feastrex etc. can sound rough when pushed with complex music.
I have heard the Feastrex three times. I thought they sounded ok, but they didn't do so well with complex music or volume.
What I expect to figure out with the open baffle is if I am hearing these kind of problems including garbling, roughness on peaks, coherence, treble smoothness etc. At least down to the 60hz or so that an open baffle can do.
Any suggestions or ideas about these drivers?
Short answer is no, a 15in driver can't do it all, especially when built to a price. Don't get me wrong, $400 is not loose change down the back of the sofa, and the AN drivers are usually reasonable for what they are, but you're not going to get Altec / Olson levels of engineering quality. Still, I suspect it'll do a lot of things ~good enough for a lot of people, and you've got a heck of a lot of driver there for the money.
Re general useage, Q on the larger ANs seems to be somewhat higher than claimed, if user measurements of the 12in units is anything to go by. That's not necessarily a bad thing if you're using them on baffles; they'll go a bit lower before rolling off. Linear excursion isn't huge, so dynamic headroom will be limited, albeit less so than the smaller units will be. Given that a BR even approaching optimal would be of epic proportions, a baffle is probably the best way to use them -you might feel like low passing them & partnering with a suitable 15in woofer at some point.
As for distortion, getting a cone as large as this to cover such a wide BW isn't easy -you can see some of the consequences on the impedance plot, which shows the cone breakup modes. Up side, you'll probably suffer a bit less elsewhere due to the size of the cone & the reduced excursion relative to smaller units. YMMV as ever of course. You might find these beasts better at rock etc. than some of the smaller drivers, although very complex material might not be so good. Keep us posted on your experiences.
Re general useage, Q on the larger ANs seems to be somewhat higher than claimed, if user measurements of the 12in units is anything to go by. That's not necessarily a bad thing if you're using them on baffles; they'll go a bit lower before rolling off. Linear excursion isn't huge, so dynamic headroom will be limited, albeit less so than the smaller units will be. Given that a BR even approaching optimal would be of epic proportions, a baffle is probably the best way to use them -you might feel like low passing them & partnering with a suitable 15in woofer at some point.
As for distortion, getting a cone as large as this to cover such a wide BW isn't easy -you can see some of the consequences on the impedance plot, which shows the cone breakup modes. Up side, you'll probably suffer a bit less elsewhere due to the size of the cone & the reduced excursion relative to smaller units. YMMV as ever of course. You might find these beasts better at rock etc. than some of the smaller drivers, although very complex material might not be so good. Keep us posted on your experiences.
Can you tell me the models of Altec and Olsens you are referring too (and are they full range)? I been recommended the Altec BiFlex's by someone recently.
I have liked a lot of the vintage Altec systems I have heard, but none of them were the full range drivers.
Help me out here. My understanding of Q is that it's a measurement of how stiff the driver is at excursion, or how compliant it is? I know that Q can be adjusted electrically in subwoofers.
I don't know what BR stands for but as I understand it, it is the volume of a speaker enclosure.
I was wondering if there are any tweaks to increase the BR (is this correct) of an enclosure? I remember reading about KEF using something like powdered carbon in their small speakers to mimic a larger volume enclosure.
I have liked a lot of the vintage Altec systems I have heard, but none of them were the full range drivers.
Help me out here. My understanding of Q is that it's a measurement of how stiff the driver is at excursion, or how compliant it is? I know that Q can be adjusted electrically in subwoofers.
I don't know what BR stands for but as I understand it, it is the volume of a speaker enclosure.
I was wondering if there are any tweaks to increase the BR (is this correct) of an enclosure? I remember reading about KEF using something like powdered carbon in their small speakers to mimic a larger volume enclosure.
For the main part I was thinking of Olson's 15in unit (you're not likely to run across one in a hurry), and some of Altec's coax drivers, esp. the 604.
Driver Qts = (Qe*Qm)/(Qe+Qm). It's a mathematical construct essentially expressing the total damping (electrical and mechanical) of a drive unit at resonance. A low Qt indicates a driver with a very high degree of self damping; a high Q driver conversely is less well (even under) damped at resonance.
BR = Bass Reflex (or vented box).
I can't speak for KEF, but generally speaking, not really -not something that'd make a significant difference to the cabinet volumes we'd be talking of here at any rate.
Driver Qts = (Qe*Qm)/(Qe+Qm). It's a mathematical construct essentially expressing the total damping (electrical and mechanical) of a drive unit at resonance. A low Qt indicates a driver with a very high degree of self damping; a high Q driver conversely is less well (even under) damped at resonance.
BR = Bass Reflex (or vented box).
I can't speak for KEF, but generally speaking, not really -not something that'd make a significant difference to the cabinet volumes we'd be talking of here at any rate.
Oy! BR= Bass Reflex. Now I feel dumb!
The 5.6 enclosure that Common Sense recommends doesn't seem that huge, especially next to my big Hornings! I could do bigger.
What would a bigger enclosure do for the sound, besides allow for lower bass. What would it do for the other performance characteristics? Higher efficiency?
The 5.6 enclosure that Common Sense recommends doesn't seem that huge, especially next to my big Hornings! I could do bigger.
What would a bigger enclosure do for the sound, besides allow for lower bass. What would it do for the other performance characteristics? Higher efficiency?
'I know that many of the single driver systems - Lowthers, Fostex, Feastrex etc. can sound rough when pushed with complex music.'
This is and has been my primary complaint about paper FR drivers. But after ALOT of thought and ALOT of listening, I decided they are still superior to complex crossovers, polymer cones, and waterfall plots that look like Ayer's Rock. But pick your poison. I haven't heard Feastrex. Fostex is good at low volume. I can't recommend Lowther to anyone. AN is the best I've heard so far.
This is and has been my primary complaint about paper FR drivers. But after ALOT of thought and ALOT of listening, I decided they are still superior to complex crossovers, polymer cones, and waterfall plots that look like Ayer's Rock. But pick your poison. I haven't heard Feastrex. Fostex is good at low volume. I can't recommend Lowther to anyone. AN is the best I've heard so far.
I prefer active crossovers or better no crossovers at all 
I agree that the limitations of full rangers might be preferable to the mucking up complex crossovers and multiple drivers can do.
I am beginning to understand the physics of the driver in the cabinet better thanks to this forum!
So the stiffer or higher Q driver needs a larger box because more air volume will allow the driver to have more excursion and reach to lower hertz and also lower the resonance of the box?
What about a passive radiator as opposed to vents or sealed? I know many sealed speakers and subs use them to play lower. How about in this application?
Also, I have seen the threads about stuffing speakers with various materials. Including experiments with Pearlite. This can allow greater air adsorption.
Pearlite Thread
Theoretically would a gas that compressed easier than air be the ultimate fill?
I agree that the limitations of full rangers might be preferable to the mucking up complex crossovers and multiple drivers can do.I am beginning to understand the physics of the driver in the cabinet better thanks to this forum!
So the stiffer or higher Q driver needs a larger box because more air volume will allow the driver to have more excursion and reach to lower hertz and also lower the resonance of the box?
What about a passive radiator as opposed to vents or sealed? I know many sealed speakers and subs use them to play lower. How about in this application?
Also, I have seen the threads about stuffing speakers with various materials. Including experiments with Pearlite. This can allow greater air adsorption.
Pearlite Thread
Theoretically would a gas that compressed easier than air be the ultimate fill?
I was looking up Sodium Hexafluoride gas to see if it was toxic and came across this, I guess it's not!
Mythbusters funny voices
Mythbusters funny voices
With the help of a friend I made the open baffle enclosure for the Nirvanas.
Upon firing them up they sound very good. They do have an incredible cohesive sound from top to bottom. They sound a bit tizzy on the top and a bit rough. But that's what you can expect from a driver before it breaks in.
They are pretty directional, but do have a wide sweet spot.
They have tremendous dynamics and 'jump' factor, They a great deal more fleshed out than many of the other single drivers I have heard.
This will be a fun ride
Upon firing them up they sound very good. They do have an incredible cohesive sound from top to bottom. They sound a bit tizzy on the top and a bit rough. But that's what you can expect from a driver before it breaks in.
They are pretty directional, but do have a wide sweet spot.
They have tremendous dynamics and 'jump' factor, They a great deal more fleshed out than many of the other single drivers I have heard.
This will be a fun ride
planet10 said:
Just a friendly correction guys. The gas in question is called Sulfur Hexafluoride or SF6. There's no sodium in this cocktail.
It is used in the high voltage industry as a fill gas where the voltages between conductors is too high for ordinary air and the electric potential will ionize and create a current path. The holdoff voltage for SF6 is very much higher than air, preventing corona from forming at higher voltages than are possible in air.
Well I now have 150 hours or so on the drivers. All in all I am very impressed with these drivers. They are really dynamic and meaty sounding speakers.
They have a lot of bass, even in the open baffle I currently have them in.
They do very well against my reference speakers. They are real giant killers for the price.
Strengths: Meaty dynamic sound, great for Rock and blues etc.; not afraid of punishment and volume ; great coherence of frequencies, especially nice with male vocals and trombone; deep punchy bass even in open baffle - can tell that in a cabinet they will have very good bass; very clear highs that have bite and remarkably transparent - one of the best drivers of any kind I have heard to reproduce the metalness of cymbals and bells ; easy to drive by almost any amp.
There are only two issues that I have with them. I wonder how much the open baffle might be influencing this vs. using a good cabinet.
A bit rough on dynamics in the treble: this might be due to many things other than the speaker, so I am reluctant to call this a real issue.
Detail: They have a lot of apparent detail and that great coherence that a single driver can have. But i am wondering if they might be short of the detail of a reference speaker. I just feel sometimes that there might be more there that I am missing. This could be because of the size and weight of the cone or interference from the rear wave of driver in the room, or the 15Khz limitations of the speaker.
Coloration: There is a persistent 'papery' coloration, sort of a smearing 'shhh' sound. This is not prominent, but it is there all the time. It sounds sounds like paper rubbing together.
So I am going to try a few things before I invest the considerable time and money to make good cabinets. If anybody has other suggestions, let me know.
Try a super-tweeter. I may try the Tonian Labs ones or the Raven ribbons with a steep slope crossover to get the above 15Khz information that is missing. I was recently tested and can hear +/- 4 db to 22Khz, pretty good for a 40 plus guy, so this might make a difference for me.
I would like to try a filter between the positive and negative terminals that is meant to smooth the highs. I forget what this is called? A zener? I have one that a friend made for my other speakers, but it really deadens the sound (probably not the right values). Does anyone know what the right values would be for this driver?
I would like to try treating the driver to reduce the papery coloration I am hearing from it. I have the most confidence that this is one thing that will improve the sound. I would like to try the eNable process and any other treatments that might help. There is a lot of surface area to cover on these drivers so I won't be using any C37-.
They have a lot of bass, even in the open baffle I currently have them in.
They do very well against my reference speakers. They are real giant killers for the price.
Strengths: Meaty dynamic sound, great for Rock and blues etc.; not afraid of punishment and volume
; great coherence of frequencies, especially nice with male vocals and trombone; deep punchy bass even in open baffle - can tell that in a cabinet they will have very good bass; very clear highs that have bite and remarkably transparent - one of the best drivers of any kind I have heard to reproduce the metalness of cymbals and bells ; easy to drive by almost any amp.There are only two issues that I have with them. I wonder how much the open baffle might be influencing this vs. using a good cabinet.
A bit rough on dynamics in the treble: this might be due to many things other than the speaker, so I am reluctant to call this a real issue.
Detail: They have a lot of apparent detail and that great coherence that a single driver can have. But i am wondering if they might be short of the detail of a reference speaker. I just feel sometimes that there might be more there that I am missing. This could be because of the size and weight of the cone or interference from the rear wave of driver in the room, or the 15Khz limitations of the speaker.
Coloration: There is a persistent 'papery' coloration, sort of a smearing 'shhh' sound. This is not prominent, but it is there all the time. It sounds sounds like paper rubbing together.
So I am going to try a few things before I invest the considerable time and money to make good cabinets. If anybody has other suggestions, let me know.
Try a super-tweeter. I may try the Tonian Labs ones or the Raven ribbons with a steep slope crossover to get the above 15Khz information that is missing. I was recently tested and can hear +/- 4 db to 22Khz, pretty good for a 40 plus guy, so this might make a difference for me.
I would like to try a filter between the positive and negative terminals that is meant to smooth the highs. I forget what this is called? A zener? I have one that a friend made for my other speakers, but it really deadens the sound (probably not the right values). Does anyone know what the right values would be for this driver?
I would like to try treating the driver to reduce the papery coloration I am hearing from it. I have the most confidence that this is one thing that will improve the sound. I would like to try the eNable process and any other treatments that might help. There is a lot of surface area to cover on these drivers so I won't be using any C37-
.Hello,
I would like to add my $0.02 to your thoughts.
The ANs are fantastic drivers for the money. I have the standard 8" ones and although a bit bass shy, they do so many things right.
Give your drivers more time, >500 hrs and you will find they do not need any sort of equalization. No notch filters and such. 150 hours on these beasts is too little.
A little bit about speaker theory and what you are trying to achieve:
think of the speaker as a mass-spring system. The speaker cone is the mass and the magnet (and air behind) is the spring. These AN drivers have big (very big) magnets, which is another way of saying that they are bound by a stiff spring. In a mass-spring system, if you lower the mass OR increase the stiffness of the spring, the system's natural frequency is increased. Similarly, in a typical full range speaker, the cones are light and the magnets are big... meaning that your natural frequency of resonance will be high. This has the effect of curtailing the bass, another way of saying that the speaker is not allowed to move as much air as it wants to, or that it is over-damped.
Now, putting such a speaker in a closed box will increase the springiness of the air behind... if you follow. As opposed to that, an open baffle will provide less damping, or shall we say overdamp the speaker the least.
You will find that you get more bass in an open baffle with these speakers than perhaps in a box (I have not tested this, but I suspect it is so). Nelson Pass is working on something similar. He is of course going to relieve the full range drivers below 200-300 Hz and put a woofer to perform this duty. This, probably is the best approach to get the most out of your full range driver.
A book on basic Speaker Design by David Weems is an excellent place to start. You can also read the article by Nelson Pass on www.passdiy.com about full range drivers, a good resource for equalizing their response.
Dave and Scottmoose, kindly correct me if I wrote incorrectly.
Regards,
Rahul
I would like to add my $0.02 to your thoughts.
The ANs are fantastic drivers for the money. I have the standard 8" ones and although a bit bass shy, they do so many things right.
Give your drivers more time, >500 hrs and you will find they do not need any sort of equalization. No notch filters and such. 150 hours on these beasts is too little.
A little bit about speaker theory and what you are trying to achieve:
think of the speaker as a mass-spring system. The speaker cone is the mass and the magnet (and air behind) is the spring. These AN drivers have big (very big) magnets, which is another way of saying that they are bound by a stiff spring. In a mass-spring system, if you lower the mass OR increase the stiffness of the spring, the system's natural frequency is increased. Similarly, in a typical full range speaker, the cones are light and the magnets are big... meaning that your natural frequency of resonance will be high. This has the effect of curtailing the bass, another way of saying that the speaker is not allowed to move as much air as it wants to, or that it is over-damped.
Now, putting such a speaker in a closed box will increase the springiness of the air behind... if you follow. As opposed to that, an open baffle will provide less damping, or shall we say overdamp the speaker the least.
You will find that you get more bass in an open baffle with these speakers than perhaps in a box (I have not tested this, but I suspect it is so). Nelson Pass is working on something similar. He is of course going to relieve the full range drivers below 200-300 Hz and put a woofer to perform this duty. This, probably is the best approach to get the most out of your full range driver.
A book on basic Speaker Design by David Weems is an excellent place to start. You can also read the article by Nelson Pass on www.passdiy.com about full range drivers, a good resource for equalizing their response.
Dave and Scottmoose, kindly correct me if I wrote incorrectly.
Regards,
Rahul
Ah, I meant to say Zobel network above!
My lowthers took a year to break in fully.
I have played the ANs with some active EQ that comes in the Sonic Studio Amarra Dac, rasing the bass below 60hz. The AN move some serious air with this. And they do actually play below 60hz quite a bit, I have heard some bass down to about 30 on some electronica. Even with this, I don't hear distortion in the other frequencies. So I think they will really play low in the right box.
My lowthers took a year to break in fully.
I have played the ANs with some active EQ that comes in the Sonic Studio Amarra Dac, rasing the bass below 60hz. The AN move some serious air with this. And they do actually play below 60hz quite a bit, I have heard some bass down to about 30 on some electronica. Even with this, I don't hear distortion in the other frequencies. So I think they will really play low in the right box.
They will, but you'd need a hell of a big box.
Re Ra7's comments, the spring / mass analogy is a good one, although the AN15 isn't bound by that stiff a 'spring' -the officially published Qe & Qt (indicating electrical & total damping at resonance) is middling, placing the mass-corner at ~112.5Hz.
Given the kind of cabinet sizes the driver really needs, an OB is indeed probably one of the more domestically practical means of running it; too small a box & you won't have any LF to speak of & it'll likely sound horribly compressed. You could always add an additional bass driver, or even, run monopole bass & OB on the AN, like a Basszilla.
Re Ra7's comments, the spring / mass analogy is a good one, although the AN15 isn't bound by that stiff a 'spring' -the officially published Qe & Qt (indicating electrical & total damping at resonance) is middling, placing the mass-corner at ~112.5Hz.
Given the kind of cabinet sizes the driver really needs, an OB is indeed probably one of the more domestically practical means of running it; too small a box & you won't have any LF to speak of & it'll likely sound horribly compressed. You could always add an additional bass driver, or even, run monopole bass & OB on the AN, like a Basszilla.
What about an enclosure that has a large woofer in the back that is wired out of phase to the main speaker, crossed over at about 50 hz, maybe about 4 db less sensitivity than the AN?
The surface a large cone pushing on the air in phase (because it's facing backwards) would enhance the 'springiness' of the air? Is that like a reverse isobaric?
Would that work, or would that just smear the sound?
The surface a large cone pushing on the air in phase (because it's facing backwards) would enhance the 'springiness' of the air? Is that like a reverse isobaric?
Would that work, or would that just smear the sound?
I think both issues are connected. The coloration you described causes missing of details in a certain ranges. The firts step is:
Just do not switch the music off for two weeks (it is not necesary at high levels) and there will be an audable difference. I am afraid therefore, that some coloration will remain. It is due to the type of paper the manufacturer uses and exists maybe in all the Audio Nirvana models (I have an experience with Super 6.5 Cast Frame and Super 8 Cast Frame). A carefully designed notch can fix the problem without a negative affect to the sound at all. Unfortunately I have no experience with AN 15" driver and can't suggest the proper frequency, but try between 6 and 8KHz...
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