Hi,
You've lost me, engineering defines all sonic possibilities
and that defines some severe real visual constraints.
rgds, sreten.
c'mon sreten,
Don't be the xmas grinch. (And that is hard to say coming from a total nontheist!)
yoshy has some quality drivers and, honestly, that is half the battle. He is going with an active setup and, I presume, an active crossover. the basics are right so, thereafter, he can modify, if needed, to get it right.
As you may realise, I believe active is the best way. Listening to Mark Knoepler, "Get Lucky" 2009 on my active 3 ways is sensational. He produces CDs with full dynamic range and it sounds great on them no matter what the volume. Avalon from the same named Roxy Music album is another where quality of production really shines through, even more so at very high volumes. The people in the street, and there is a lot of them have told me they like it too. 🙂
Frank
Don't be the xmas grinch. (And that is hard to say coming from a total nontheist!)
yoshy has some quality drivers and, honestly, that is half the battle. He is going with an active setup and, I presume, an active crossover. the basics are right so, thereafter, he can modify, if needed, to get it right.
As you may realise, I believe active is the best way. Listening to Mark Knoepler, "Get Lucky" 2009 on my active 3 ways is sensational. He produces CDs with full dynamic range and it sounds great on them no matter what the volume. Avalon from the same named Roxy Music album is another where quality of production really shines through, even more so at very high volumes. The people in the street, and there is a lot of them have told me they like it too. 🙂
Frank
ps. sreten, my wife and I were on the Isle of Wight, just up the water, so-to-speak, in August staying with friends. A beautiful part of the world. (Since you don't allow PMs.)
Frank
Frank
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I spent my whole adult life doing engineering. Often the first task is to find out from "marketing" exactly what they want and what they are willing to pay for it. Invariably it comes to trade-offs. Pinning the marketing people down enough to write a proposal can be, shall we say, challenging. What do they want? Everything. How much will they pay? Less than any positive number you can name.
You can't build what you want unless you know what you want.
Yoshy, some 15 years ago I built a similar system for a friend but it was a 3 way.
The woofers were Audio Concepts DV12, the mid was a 18W8546 and the tweeter was a 2905-9500. The cabinet sides were 9" which gave us enough volume.
Here are my observations.
1. While Mike Dzurko (of ACI) had no reservations of us using the wofoers face up/down we did notice some cone sag after a few years of use. The XXLS woofers have an even heavier cone than the DV12.
2. The baffle step you envision for a 9" baffle (in the speaker I built) will be a lot less due the angle of the baffle so you will have to fine tune this by ear.
3. As PeteMck sadi, I would leave out the HiVi and use maybe a W18 from SEAS instead. Dont use a driver just becuase you got it. You have to first understand the room, and design considerations (what music, movies, how loud, etc..) before you start a design.
4. The advatages of a 3 way with a single driver operating in much of the 100-1000hz range is that much of the baffle step would be applicable to only this driver.
As DIYers one of the biggest advantages we have is that we can build a speaker that mates with the room we live in. this is particularly true for the bas response which is so dependant on the room boundaries.
If this is your first system then I would strongly consider looking at system from Troels, John "Zaph", Tony Gee, etc..
Look at the Troels DTQWT, Ekta Grande (if 2 7" woofers are not adequate you could expand this design to 2 10" woofers mated to a 7" midwoofer), Prelude (but using 2 10C77 woofers mated to a C18H), Cyclops....you could even start with the Ekta Grande style and expand the cabient to use say SEAS W26FX01, W16 midbass, and T29 tweeter.
Tony Gee has the Modulus, BlackBox, Progress, etc.. each of which can be expanded to offer more SPL. For example the Blackbox could be expanded to use 2 RS265/270 woofers instead of 1 (mated to the 2" RS52 dome mid and 1" R28 tweeter) ...in most cases doubling up on teh woofer will also mean upgrqading the midwoofer's size to deliver more SPL.
Remember modifying any design would mean that much of the crossover would have to redesigned. The advantages of using an existing design would then be limited to knowing which drivers mate well and also if any of these drivers have peaks that needs to be notched out you will atleast have those values at hand.
hmmm, you have all drivers already ?
and you plan to go active ?
maybe use DSP(digital filter) ?
well, if it fails, most of your additional investment might be "reused" for further trials
but if it fails the first time, it may also fail the second and third time, etc
hard to say really
that is the tricky aspect
apart from that its just a lot of work
if you proceed, I would suggest a simple experimental modular design, without much effort on finish etc
and you plan to go active ?
maybe use DSP(digital filter) ?
well, if it fails, most of your additional investment might be "reused" for further trials
but if it fails the first time, it may also fail the second and third time, etc
hard to say really
that is the tricky aspect
apart from that its just a lot of work
if you proceed, I would suggest a simple experimental modular design, without much effort on finish etc
This design is mostly as a radical departure from the text book experiments I did. I had a few failures. Some which worked perfectly, some just made sound other music. The point of a hexagon was to create a 'virtual' sound source with wave reflection. The design is pretty modular; every driver is stand-alone.
If I was to start again I'd put the 2 sub on the side of a box. It would probably be a triangular prism or something.
If I was to start again I'd put the 2 sub on the side of a box. It would probably be a triangular prism or something.
The no effort on finishing until the design is finalized approach makes a lot of sense, but in my experience it just results in a progression of mdf boxes (dipole panel coming soon) in my living room. OTOH, well finished boxes tend to stay in place for a couple of years or more with few if any new builds. Which is the worse fate?
The good news here is Yoshy has chosen drivers with performance that will stand the test of time, it is just up to his measurement and DSP programming skills to get filters that work. Aesthetically, if you stay with a four way I'd prefer the W22EX. It'll be work, but since he should be able come up with something pretty listenable fairly quickly. Perfection may take a bit longer.
As for the baffle step, I have found that with 1.25" radius roundovers adding 1.25" to the flat width of the baffle as a starting point gets pretty close. Pretty much the same for 45 degree chamfers - add the width of one chamfer as seen from the front. With the larger angle of your enclosures, I'd guess that you'll get a little less effective additional width than half the total enclosure width. Maybe start with the front surface plus 1/3 the additional width of the "chamfers."
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Wonder if putting a cylinder in the middle of each enclosure will make it no longer behave as a 6 sided hexagon?
Thin fiberglass walls of the cylinder and filled with sand?
For the two midranges it could be D=230mm. It could be off center nearer the back wall or nearer the driver back and the opposite to the driver end of the enclosure can be stuffed with sound absorbent material.
Internally the walls can be formed in a such way that they form expanding or narrowing cross section towards the opposite end...
If all that makes sense?
Apart from that for such a super project I would use at least 2x12 inch subs and a bigger lower midrange such as Fane or Eminence 8 or 10 inch drivers. - sorry for mentioning such drivers in such a thread, but they really sound good.
As for the crossover frequencies I would suggest the first to be one octave above the free air resonance of the lower midrange - that would be between 100 and 160 Hz, the second crossover should be not higher than 350 Hz (one to two octaves for the low midrange) and if you use an extended range higher midrange it would be very good if it is crossed to the tweeter above 7 kHz.
Or you could cross the woofers to the lower midrange at 200 or so Hz, use it up to 800-1000 Hz as you initially intend and use a dome high midrange crossed high enough to a matching high range.
But crossing from a big paper cone to a dome driver in the middle of most vocalists range is probably not a good idea?
I have an undergoing 4-way with passive series crossovers and i have chosen crossover points as follows: 1 - 350 Hz, 2 - 4 (or 6) kHz, 3 - 12 kHz - drivers are: paper woofer, paper sealed chassis midrange, dome mid/high range and dome high range. - that's probably my best and objective opinion on 4 way systems... and i bought the drivers on purpose.
System looks great! But I would vote for forward facing woofer/woofers too. And they could be in one bigger hexagon? Optically you can make a slot between them to keep the original design conception. - more volume - more bass...
Best regards!
Thin fiberglass walls of the cylinder and filled with sand?
For the two midranges it could be D=230mm. It could be off center nearer the back wall or nearer the driver back and the opposite to the driver end of the enclosure can be stuffed with sound absorbent material.
Internally the walls can be formed in a such way that they form expanding or narrowing cross section towards the opposite end...
If all that makes sense?
Apart from that for such a super project I would use at least 2x12 inch subs and a bigger lower midrange such as Fane or Eminence 8 or 10 inch drivers. - sorry for mentioning such drivers in such a thread, but they really sound good.
As for the crossover frequencies I would suggest the first to be one octave above the free air resonance of the lower midrange - that would be between 100 and 160 Hz, the second crossover should be not higher than 350 Hz (one to two octaves for the low midrange) and if you use an extended range higher midrange it would be very good if it is crossed to the tweeter above 7 kHz.
Or you could cross the woofers to the lower midrange at 200 or so Hz, use it up to 800-1000 Hz as you initially intend and use a dome high midrange crossed high enough to a matching high range.
But crossing from a big paper cone to a dome driver in the middle of most vocalists range is probably not a good idea?
I have an undergoing 4-way with passive series crossovers and i have chosen crossover points as follows: 1 - 350 Hz, 2 - 4 (or 6) kHz, 3 - 12 kHz - drivers are: paper woofer, paper sealed chassis midrange, dome mid/high range and dome high range. - that's probably my best and objective opinion on 4 way systems... and i bought the drivers on purpose.
System looks great! But I would vote for forward facing woofer/woofers too. And they could be in one bigger hexagon? Optically you can make a slot between them to keep the original design conception. - more volume - more bass...
Best regards!
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Member
Joined 2003
You've received really some good input to consider. Personally, I'd make it a 3-way WMTMW. The old-school Hi-Vi is outclassed by the other drivers, so use it for something else and buy another pair of W15's.
For the enclosure, move the woofers to the front panel. Shorten the front sides/wings and angle them 45* to the front panel, lengthen the two rear sides, culminating in a back panel that is only wide enough for terminal blocks. Asymmetric front to back with plenty of room to absorb driver backwaves.
XO around 250 and around 1.7-1.9k. (The W15 is a great mid but, because of the HF breakup, distortion rises if driven above about 2.5k.)
Here is an example of the top-down shape:
For the enclosure, move the woofers to the front panel. Shorten the front sides/wings and angle them 45* to the front panel, lengthen the two rear sides, culminating in a back panel that is only wide enough for terminal blocks. Asymmetric front to back with plenty of room to absorb driver backwaves.
XO around 250 and around 1.7-1.9k. (The W15 is a great mid but, because of the HF breakup, distortion rises if driven above about 2.5k.)
Here is an example of the top-down shape:
ok you have alot of money for drivers, why go with a four way? why not use extended range drivers and go for a two way. I would use 12" bass drivers and some kind of tweeter that could go down to 900Hz and cross with as high order filter as posible at 1Khz.
Kip, that implies horn/waveguide and a totally different form factor than Yoshy's better half has already approved. Since he seems to want to keep her or at least avoid the expense of a divorce ... 
Hi,
Thanks for that, I didn't realise I had it turned off.
My opinion is that if your going to spend a lot of time doing something
you should think and reserch about it a lot, you don't want to be
building and researching at the same, which you can easily do.
rgds, sreten.
Hi,
I completely agree, you cannot start with a "detailed specification",
that it what you end up with after a few modelling/development/ideas
loops, hopefully moving towards understanding of the drivers being used.
rgds, sreten.
I wouldn't worry about the 5 sided, 6 sided issues. If it is lightly stuffed with fiberglass you won't see any standing wave effects. If the stuffing doesn't work then you have just as much of a problem with a 4 sided box as 6.
I would agree that a 3 way would make life simpler, but if you are committed to a 4 way then proceed. You might also combine the lower woofer and tweeter into a single volume. The tweeter needs no rear cavity and the lower woofer might benefit from it. Keep the style the same by putting a kerf line where you currently have the cabinet division.
Have you simulated the woofers and subs in the proposed volumes yet? That is an essential step to confirming everything works. (More important than our oppinions, for sure.)
Woofer sag might be an issue but you can also, like tires, rotate your woofers every season (top to bottom, etc.)
Very nice drawings, by the way.
David S.
I would agree that a 3 way would make life simpler, but if you are committed to a 4 way then proceed. You might also combine the lower woofer and tweeter into a single volume. The tweeter needs no rear cavity and the lower woofer might benefit from it. Keep the style the same by putting a kerf line where you currently have the cabinet division.
Have you simulated the woofers and subs in the proposed volumes yet? That is an essential step to confirming everything works. (More important than our oppinions, for sure.)
Woofer sag might be an issue but you can also, like tires, rotate your woofers every season (top to bottom, etc.)
Very nice drawings, by the way.
David S.
Hi,
FWIW with those drivers I'd ditch the HiVi and go 3 way, the bass
units IMO will fine in a 3 way and their potential used a lot more.
Model, read, research and model until your sure of what your going to get.
Read at least Undefinitions FAQ's and the FRD modelling guide.
Don't assume you can put the drivers in boxes and a simple active c/o
will sort it out. Work out what real facilities the active crossover needs.
Look at other large bass driver 3-ways, see if you like the look of one.
There is a classic two-box way of doing a 3-way to give small box
dispersion and big box bass. It works very well and any other
arrangement IMO is very hard to justify, go for quality.
rgds, sreten.
FWIW with those drivers I'd ditch the HiVi and go 3 way, the bass
units IMO will fine in a 3 way and their potential used a lot more.
Model, read, research and model until your sure of what your going to get.
Read at least Undefinitions FAQ's and the FRD modelling guide.
Don't assume you can put the drivers in boxes and a simple active c/o
will sort it out. Work out what real facilities the active crossover needs.
Look at other large bass driver 3-ways, see if you like the look of one.
There is a classic two-box way of doing a 3-way to give small box
dispersion and big box bass. It works very well and any other
arrangement IMO is very hard to justify, go for quality.
rgds, sreten.
Hi Frank,
As an amateur boatbuilder/sailor, I've always wanted to sail around the Isle. It may also be the lyrics of that song:
"There were three drunken maidens, all from the Isle of Wight...
They started drinking on Sunday... and didn't stop 'til Saturday night!"
Even at my advanced age, I'm up for that kind of party!😀
Best Regards,
TerryO
Another thought, since money seems to be an object. You've designed as a modular system with seperate cabinets. Why not build it that way? Start as a two way and then as time goes on and you have a little more money, add another section. That would also let you sort out the crossover gradually along the way and make the design job less daunting.
David S.
David S.
Really? I think that makes it tougher than having the parts from the get go. Especially since he has the advantage of going active. Hey, if a hack like me can get away with it...
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