Hi, all...
I'm considering building my first 6th-order bandpass. I've heard consistently that these are 'tricky' to get right, so I'm a bit apprehensive.
I have WinISD and am familiar with the program. It does calculations for 6th orders... but not quite as it does for the other enclosure types. As many of you know, it doesn't give you any kind of starting point for air space (although it does recommend vent length when you input those values)--you have to manually enter values and 'see what happens' on the response curve.
So, I was wondering...
Has anyone ever constructed a 6th order (based on WinISD numbers) and tested its frequency response? Did it match up well? Would you feel comfortable using WinISD numbers here?
P. S. I know many of you will recommend Hornresp, but I can't download it... so, really... just wanting to focus on WinISD accuracy.
THANK YOUI!
I'm considering building my first 6th-order bandpass. I've heard consistently that these are 'tricky' to get right, so I'm a bit apprehensive.
I have WinISD and am familiar with the program. It does calculations for 6th orders... but not quite as it does for the other enclosure types. As many of you know, it doesn't give you any kind of starting point for air space (although it does recommend vent length when you input those values)--you have to manually enter values and 'see what happens' on the response curve.
So, I was wondering...
Has anyone ever constructed a 6th order (based on WinISD numbers) and tested its frequency response? Did it match up well? Would you feel comfortable using WinISD numbers here?
P. S. I know many of you will recommend Hornresp, but I can't download it... so, really... just wanting to focus on WinISD accuracy.
THANK YOUI!
I've built a couple of BP6 boxes using winISD that measured very close to the model. I like the simplicity/ease of use of winISD compared to hornresp for modelling vented, sealed and BP boxes. As long as you build the box close enough to the modelled volumes (and the TS parameters you use are accurate) you should be close enough.
Rob.
Rob.
They do suggest the automatic guess for 6th is bad, but you can enter your own numbers and it models pretty well to reality.
The problem I had with any of the drivers I tried was unrealizable ports. Just not easy to have a 4 inch 6 foot port! Passive radiators become the requirement, but that gets big and expensive as you need at least 2X sd for a radiator.
After much attempting, I returned to low Q sealed boxes again. .6 is usually easy. Critical Q of .5 not always.
The problem I had with any of the drivers I tried was unrealizable ports. Just not easy to have a 4 inch 6 foot port! Passive radiators become the requirement, but that gets big and expensive as you need at least 2X sd for a radiator.
After much attempting, I returned to low Q sealed boxes again. .6 is usually easy. Critical Q of .5 not always.
Hey, tvr. Yeah, based on my general knowledge, the WinISD projections looked about right. But I've read some people saying it's spot-on... and others saying it's 'totally worthless'... so I thought I would ask the question directly. Thanks for weighing in!
Well, Perry... I don't know that there's a particular draw. I've had these in a 4th-order bandpass and LOVED them, but I thought I would try something new.
I thought about simple closed or vented enclosure, but I'm intrigued by the low, flat response that the 6th order promises (fingers crossed!).
It'll be a big box, but it's going into a gutted hatchback, so space isn't an issue at all.
I thought about simple closed or vented enclosure, but I'm intrigued by the low, flat response that the 6th order promises (fingers crossed!).
It'll be a big box, but it's going into a gutted hatchback, so space isn't an issue at all.
Hey, Rob... while you're here...
Can I ask what you thought about the 'sound' of the 6th orders you've done? I've read everything I can find about them, but I've never listened to one with my own two ears.
Was the transient response decent... or was it boomy/muddy? Somewhere in between?
I would be fascinated to hear your opinion!
6th order can be built for sound quality.
But is typical for guys looking for SPL peak
Maybe what gives them a bad reputation, since the can be
high tuned one note wonders.
With 6th order the rear chamber is also vented
so it unloads just like a reflex does.
So the model should show you cone excursion
and a good idea where to put the over excursion / sub sonic filter
on your amplifier.
In a generalized statement, you have a ported system
controlling the lower and upper cutoff.
So your adding the typical poor transient response
of a reflex to both ends of the pass band.
4th order somewhat more appealing to sound quality
and power handling. since rear chamber behaves
more like a sealed enclosures and does not unload.
but can be tuned much lower than what a sealed box would
do.
But is typical for guys looking for SPL peak
Maybe what gives them a bad reputation, since the can be
high tuned one note wonders.
With 6th order the rear chamber is also vented
so it unloads just like a reflex does.
So the model should show you cone excursion
and a good idea where to put the over excursion / sub sonic filter
on your amplifier.
In a generalized statement, you have a ported system
controlling the lower and upper cutoff.
So your adding the typical poor transient response
of a reflex to both ends of the pass band.
4th order somewhat more appealing to sound quality
and power handling. since rear chamber behaves
more like a sealed enclosures and does not unload.
but can be tuned much lower than what a sealed box would
do.
I'm not against someone doing something for the purpose of learning but...
The first thing that comes to mind is, as you stated, a one note wonder.
Another problem, for wider range 6th enclosures, is the rolloff of the enclosure and the transfer function of the vehicle aren't supposed to work well together.
Before crossovers and subsonic filters, 6th order may have had a benefit but now, they're not generally practical, cost/benefit ratio.
The first thing that comes to mind is, as you stated, a one note wonder.
Another problem, for wider range 6th enclosures, is the rolloff of the enclosure and the transfer function of the vehicle aren't supposed to work well together.
Before crossovers and subsonic filters, 6th order may have had a benefit but now, they're not generally practical, cost/benefit ratio.
Hey, Dragon... thanks for the info and putting things into perspective. Yeah, I know a lot of SPL guys use them (maybe I should have taken a hint!). I guess I was thinking that if the passband were narrow enough, the 6th-order (as I modeled it anyway) would give me good cone control, perhaps resulting in accurate transient response.
But I know that other factors (like group delay) are present. I don't know... just throwing it out there to see what you guys thought!
I think I've decided against it. I have it on good authority that these subs sound great in an closed box, so I'll probably just go with that. I had them in a 4th-order bandpass back in the day (20 years ago), and to my memory, they were INCREDIBLE (but that may have been my young, inexperienced ears talking). I think that's why I continue to be drawn to a bandpass, whatever its form.
Thanks!
Very interesting, Perry. The dynamics of this design in the vehicle is something I never even considered. Thanks for that.
I think I'm going sealed. This discussion helped me to put the 6th-order option to bed, though, and I appreciate that!
Cheers!
qObsession,
FWIW I've noticed through my experience with various enclosures in the car audio realm that most subs that perform well in a sealed enclosure also perform proportionally well in a 4th order bandpass. Equally worth noting, we've found that the majority of subs designed to work well for use in vented/reflex enclosures exhibit similar performance in parallel 6th order bandpass enclosures and moderately the same in series tuned 6th order bandpass. Your mileage may vary, but I feel the 'secret sauce' lies in a solid understanding of the way qes and qms influence the desired sub for your enclosure. Also, understanding cabin gain and tuning for the res freq of the specific vehicle will allow for a tuning/q that compliments the acoustics of the specific environment and thus take advantage of a non-conventional approach to avoid group delay/excessive excursion/excessive vent velocity/etc. Good luck with your build....if you feel like experimenting, loading a sealed enclosure in an isobaric configuration coupled with adequate power can yield some interesting results in a space friendly cabinet while still maintaining a strict reproduction of the original program material....and you can design it easily with winds and feel confident that, if built dimensionally accurate, will yield results very close to your models...
VB,
LL
FWIW I've noticed through my experience with various enclosures in the car audio realm that most subs that perform well in a sealed enclosure also perform proportionally well in a 4th order bandpass. Equally worth noting, we've found that the majority of subs designed to work well for use in vented/reflex enclosures exhibit similar performance in parallel 6th order bandpass enclosures and moderately the same in series tuned 6th order bandpass. Your mileage may vary, but I feel the 'secret sauce' lies in a solid understanding of the way qes and qms influence the desired sub for your enclosure. Also, understanding cabin gain and tuning for the res freq of the specific vehicle will allow for a tuning/q that compliments the acoustics of the specific environment and thus take advantage of a non-conventional approach to avoid group delay/excessive excursion/excessive vent velocity/etc. Good luck with your build....if you feel like experimenting, loading a sealed enclosure in an isobaric configuration coupled with adequate power can yield some interesting results in a space friendly cabinet while still maintaining a strict reproduction of the original program material....and you can design it easily with winds and feel confident that, if built dimensionally accurate, will yield results very close to your models...
VB,
LL
Hey, LL... thanks for this information and the well wishes on the build.
I've read and read and read, but my 'real world experience' is limited, so I love hearing from experienced builders.
It's funny... your proposition about 4th::sealed and 6th::vented enclosures makes so much sense, but I've never thought of it that way!
As for isobaric loading, I've definitely thought about it. At first, I found the construction aspects (i.e., conjoining baffles of each driver) of it intimidating (I know... NOOB!). I think I could pull it off, and it would definitely save some space, but I have a LOT of space in the car in which I'm installing it, so I'm leaning toward more output by using the drivers individually.
Not to tax you, but do you feel like isobaric loading gives you some additional SQ? I've heard technical things like 'non-linearities are averaged,' but I don't know how that translates in the real world of cars, ears, and brains!
I've read and read and read, but my 'real world experience' is limited, so I love hearing from experienced builders.
It's funny... your proposition about 4th::sealed and 6th::vented enclosures makes so much sense, but I've never thought of it that way!
As for isobaric loading, I've definitely thought about it. At first, I found the construction aspects (i.e., conjoining baffles of each driver) of it intimidating (I know... NOOB!). I think I could pull it off, and it would definitely save some space, but I have a LOT of space in the car in which I'm installing it, so I'm leaning toward more output by using the drivers individually.
Not to tax you, but do you feel like isobaric loading gives you some additional SQ? I've heard technical things like 'non-linearities are averaged,' but I don't know how that translates in the real world of cars, ears, and brains!