Greetings Gents,
I'm posting this here, as I've been a Full-Ranger devotee since the Saburos I built, and documented here, a couple of years ago.
The question of a Sub came up with a friend of mine, who (very satisfyingly) thought my stereo was the best he's ever heard, except for the (not so satisfyingly) lack of a really low end.
He thought a subwoofer would be a great idea. Is this a good idea? His argument was that cross-over related distortion would be placed in an area of the spectrum where it would be least noticeable to the human ear. Furthermore, he opined that relieving the Saburos of trying to cope with low frequencies would liberate them to do better at what they do best.
He makes it sound so uncomplicated, but I wonder . . .
I'd really like to hear from this esteemed group.
To fill in some blanks, I'm using a modern Dynakit ST 70 for driving the Saburos (outfitted with Planet-Dave's super duper drivers . . . darn, can't remember which. Enabled 126's, I think) in a room that's 26 x 14 feet, with the speakers firing across the width of the room.
Thanks in advance,
Brenton
I'm posting this here, as I've been a Full-Ranger devotee since the Saburos I built, and documented here, a couple of years ago.
The question of a Sub came up with a friend of mine, who (very satisfyingly) thought my stereo was the best he's ever heard, except for the (not so satisfyingly) lack of a really low end.
He thought a subwoofer would be a great idea. Is this a good idea? His argument was that cross-over related distortion would be placed in an area of the spectrum where it would be least noticeable to the human ear. Furthermore, he opined that relieving the Saburos of trying to cope with low frequencies would liberate them to do better at what they do best.
He makes it sound so uncomplicated, but I wonder . . .
I'd really like to hear from this esteemed group.
To fill in some blanks, I'm using a modern Dynakit ST 70 for driving the Saburos (outfitted with Planet-Dave's super duper drivers . . . darn, can't remember which. Enabled 126's, I think) in a room that's 26 x 14 feet, with the speakers firing across the width of the room.
Thanks in advance,
Brenton
I have used the stealthWoofers for the FH3 with Victor, with the front firing Soobs that won't be helpful, but something like a good pair of 6 1/2 or 8" or even 10" per side could go a long way to putting a HUGE grin on your buddies face XO them Rel-style to start.
Drivers are FE126eN #121/122 Natural with Brown spots
dave
Drivers are FE126eN #121/122 Natural with Brown spots
dave
Hi Scott,
Yes, my friend, John Sehring by name, was recommending dual subs. He's designed and built some in his time, and is a fan of using two drivers per box, facing eachother, fed out of phase. So only the magnet and basket of one of them protrudes from the box. Apparently this configuration enables the same frequency extension from a box that is much reduced in size.
Yes, my friend, John Sehring by name, was recommending dual subs. He's designed and built some in his time, and is a fan of using two drivers per box, facing eachother, fed out of phase. So only the magnet and basket of one of them protrudes from the box. Apparently this configuration enables the same frequency extension from a box that is much reduced in size.
Called isobaric configuration.
IMHO, a bit of a waste of drivers - if you're dedicating some space for subwoofers, might as well make use of all the cone area they have to offer.
YMMV, of course.
IIRC (to use as many acronyms as possible), Sabs go to ~70Hz, and it'd be wise to give them a low-cut to stop the low bass getting to the little Fostexes.
Isobarik compund driver. It does reduce the box size by half, but the cost is high. Only a valid approach if the reduction of box volume trumps all other considerations.
I prefer 2 woofers loaded push-push -- the box will be 4 x as big for the same extention, but you get 2x the cone area (reducing distortion), gives the potential for 6 dB motr output, and done right dramatically reduce the load on the box.
dave
I've just hooked up a cheap sub (Kef PSW2000) to my Vulcans which I've fitted with Fostex Fe203en-s's. I did it more for fun then anything else, expecting to prove to myself that it was a bad idea, but frankly I'm amazed at the improvement. Next step is a really good subwoofer, I'm thinking of the 12" Morel kit on Wilmslow Audio. Any suggestions?
A 15"er or two per side would be fun.
Give them lots of power, eq to go very low.
If she asks why you've suddenly got subwoofers, put a movie on.
As Dave mentions, isobaric loading is useful for freeing up space since theoretically it only requires 1/2 the volume. In practice, a bit more than that due to the volume taken up by the internal driver & coupling chamber, so work on a basis of a box approx. 2/3 the size of the original. Notionally, it offers reduced distortion relative to a single unit. In practice, it doesn't necessarily work that way since the isobaric term isn't strictly accurate, and there is also differential VC heating. It does work to an extent, but it's generally more trouble than it's worth.
40Hz actually. That was the point.
Since the 203 has a lower Q than Vulcan was designed for, it will have slightly reduced LF gain -Vulcan is also a 40Hz horn, so if you want something below that, a couple of subs are a good idea. I'm not a huge fan of Morel drivers, although they're certainly interesting looking devices, and after rubbish experiences with Wilmslow I cannot possibly recommend them. Do your own -have a look through some of the projects in the sub. section & see what you like.
What bass driver do you like? I'm intrigued by Altec 416. The Vulcans definitely had a bit more LF with 206's, but I have more detail and HF which is also less directional with 203's.I'm between the devil and the deep blue sea. How might Krishima work with 203's?
I did actually build a pair and they sounded very nice but they were in an enormous room so it's hard to compare. What would theory say?
I did actually build a pair and they sounded very nice but they were in an enormous room so it's hard to compare. What would theory say?
Who said anything about directionality?
Inherently that is true, but the XO frequency and slope has to be factored in. Multiple subs. entail a reduction of distortion & carefully placed should either excite room modes in a more even fashion, or reduce the excitation itself. http://www.harman.com/EN-US/OurCompany/Technologyleadership/Documents/White Papers/multsubs.pdf
Since I essentially bleed Altec, the 416 is a unit I like. Just make sure it's got a big box.
As for the 203, I don't much like dropping drivers into enclosures that weren't designed for them, so can't really pass comment. They'll go in & work; how well they'd work is a case of YMMV.
Inherently that is true, but the XO frequency and slope has to be factored in. Multiple subs. entail a reduction of distortion & carefully placed should either excite room modes in a more even fashion, or reduce the excitation itself. http://www.harman.com/EN-US/OurCompany/Technologyleadership/Documents/White Papers/multsubs.pdf
Since I essentially bleed Altec, the 416 is a unit I like. Just make sure it's got a big box.
As for the 203, I don't much like dropping drivers into enclosures that weren't designed for them, so can't really pass comment. They'll go in & work; how well they'd work is a case of YMMV.
I didn't say it's no good. I said it won't have as much gain as with the driver it was designed for.
With little in the way of hard data for the 203, design is largely a case of winging it. From the minimal information Fostx provide, with a mass corner of over 600Hz it is not ideal for any kind of unsupported back-load, unless used with a high output impedance amplifier, Eq, or some form of series resistance, be it a ceramic or resistive speaker wire, when it becomes more viable. In the absense of a reasonable amount of information I'm in the realms of conjecture, especially when working purely on paper (or the electronic equivalent thereof). Sorry, but that isn't my fault.
I could fake up a set of specs. based on educated guesswork extrapolated from what Fostex have done in the past, & design something optimised as far as possible to these and the amplifier output impedance / series resistance necessary. That isn't in itself a problem, but it would still be guesswork, and I could be wrong. The question is whether you regard that as an acceptable risk or not. If you want advice then frankly, I suggest that if you're really serious about using these drivers, you should to get them measured, so you know what you're dealing with. In the meantime, you could try experimenting with some resistive speaker wire. It might help.
With little in the way of hard data for the 203, design is largely a case of winging it. From the minimal information Fostx provide, with a mass corner of over 600Hz it is not ideal for any kind of unsupported back-load, unless used with a high output impedance amplifier, Eq, or some form of series resistance, be it a ceramic or resistive speaker wire, when it becomes more viable. In the absense of a reasonable amount of information I'm in the realms of conjecture, especially when working purely on paper (or the electronic equivalent thereof). Sorry, but that isn't my fault.
I could fake up a set of specs. based on educated guesswork extrapolated from what Fostex have done in the past, & design something optimised as far as possible to these and the amplifier output impedance / series resistance necessary. That isn't in itself a problem, but it would still be guesswork, and I could be wrong. The question is whether you regard that as an acceptable risk or not. If you want advice then frankly, I suggest that if you're really serious about using these drivers, you should to get them measured, so you know what you're dealing with. In the meantime, you could try experimenting with some resistive speaker wire. It might help.
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15" drivers in a pair of sub woofers! Muwah-hah-hah-harrrrrr!
Saburos already dominate the neighborhood, according to she who must (eventually but not yet) be obeyed. She exaggerates so! No point sparing a few bucks while i have the option of building big, for the time being.
I guess its time to think about the particulars, then. I've always scoffed at the idea of subwoofers in the past, But I realize its because I was only ever exposed to cheapos deployed poorly in mass market stereo stores.
As a result, 'm completely ignorant about such things as amplification needed, cross over stuff, etc. along these lines, I was given a suggestion (repeated here for confirmation) that sub amplifiers dont need to be as hi fi-ish as my dynaco, thanks to the poor resolution of our hearing way down low. What they need to be is powerful. So it was recommended to get some inexpensive solid state amps capable of a couple hundred watts.
Thanks in advance for thoughts about this.
Saburos already dominate the neighborhood, according to she who must (eventually but not yet) be obeyed. She exaggerates so! No point sparing a few bucks while i have the option of building big, for the time being.
I guess its time to think about the particulars, then. I've always scoffed at the idea of subwoofers in the past, But I realize its because I was only ever exposed to cheapos deployed poorly in mass market stereo stores.
As a result, 'm completely ignorant about such things as amplification needed, cross over stuff, etc. along these lines, I was given a suggestion (repeated here for confirmation) that sub amplifiers dont need to be as hi fi-ish as my dynaco, thanks to the poor resolution of our hearing way down low. What they need to be is powerful. So it was recommended to get some inexpensive solid state amps capable of a couple hundred watts.
Thanks in advance for thoughts about this.
Definitely active crossovers - for subwoofer crossovers, the passive components become hugely expensive (similar expense to an amplifier), and will interact with the impedance peaks of the cabinet, giving results that are unpredictable at best.
A SS amp with a couple of hundred watts per channel would be useful - you'd be able to sacrifice efficiency (compared to the Sabs, which I assume are being driven with a lower power amplifier) to get more bass extension (Hoffman's Iron Law comes into play).
Which drivers/cabinet to choose will be dictated by...
budget
volume requirements
LF extension requirements
maximum size of the cabinet
(to a lesser extent) the amplifier with which you'll drive the sub(s)
the frequency at which you want to cross over to the Sabs.
With regards to the crossover frequency, higher would give the FR driver an easier time, but you begin to lose the benefit of horn loading.
For example, I have my FE126s in small sealed cabinets (2L a piece) and use stereo woofers with a 500Hz crossover. No point in horn loading the Fostexes, so I didn't.
If you do cross over that high, the woofers have to be in the same cabinet as the FR driver - this isn't optimal for getting an even in-room bass response: distributed subwoofers rule here.
To keep the subwoofers unlocatable (by ear), its advisable to keep the crossover reasonably steep, and at 100Hz or below.
That way, you can place the subs optimally, while keeping the FR speakers where they sound best. The link Scott posted further up the page will be of use to you.
Here's some more reading.
HTH
Chris
A SS amp with a couple of hundred watts per channel would be useful - you'd be able to sacrifice efficiency (compared to the Sabs, which I assume are being driven with a lower power amplifier) to get more bass extension (Hoffman's Iron Law comes into play).
Which drivers/cabinet to choose will be dictated by...
budget
volume requirements
LF extension requirements
maximum size of the cabinet
(to a lesser extent) the amplifier with which you'll drive the sub(s)
the frequency at which you want to cross over to the Sabs.
With regards to the crossover frequency, higher would give the FR driver an easier time, but you begin to lose the benefit of horn loading.
For example, I have my FE126s in small sealed cabinets (2L a piece) and use stereo woofers with a 500Hz crossover. No point in horn loading the Fostexes, so I didn't.
If you do cross over that high, the woofers have to be in the same cabinet as the FR driver - this isn't optimal for getting an even in-room bass response: distributed subwoofers rule here.
To keep the subwoofers unlocatable (by ear), its advisable to keep the crossover reasonably steep, and at 100Hz or below.
That way, you can place the subs optimally, while keeping the FR speakers where they sound best. The link Scott posted further up the page will be of use to you.
Here's some more reading.
HTH
Chris
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