Hi guys,
i have a pair of tb w4-657 in bass-reflex and i really want to try a double horn, like the "saburo" from frugal-horn website.
The T/S parameters are very similar to the Fostex FE103, but most of the designs are made for FE106, FE126 and FE206.
Here some data:
FE103 w4-657
qts 0.36 0.36
qes 0.40 0.39
qms 2.87 5.01
vas 6.90 6.04
What do you think about? Do you know which double horn will fit it best? Or anyway, how can i modify it to fit these drivers?
thanks a lot in advance!
i have a pair of tb w4-657 in bass-reflex and i really want to try a double horn, like the "saburo" from frugal-horn website.
The T/S parameters are very similar to the Fostex FE103, but most of the designs are made for FE106, FE126 and FE206.
Here some data:
FE103 w4-657
qts 0.36 0.36
qes 0.40 0.39
qms 2.87 5.01
vas 6.90 6.04
What do you think about? Do you know which double horn will fit it best? Or anyway, how can i modify it to fit these drivers?
thanks a lot in advance!
Hello,
103 has not enough stroke,
W4 657 is no fullrange.
Better take a W4 1320,
My real double horn the KORNET would be
a solution, with measurements.
Saburo is a single horn with two mouth, let you show
measurements, IMP and membranmovement and
compair it.
103 has not enough stroke,
W4 657 is no fullrange.
Better take a W4 1320,
My real double horn the KORNET would be
a solution, with measurements.
Saburo is a single horn with two mouth, let you show
measurements, IMP and membranmovement and
compair it.
hi hm, thanks a lot for your answer, and compliments for your horn designs, really great.
Well, I already have that drivers, the w4-657, so what do you think about adding a tweeter to it?
Well, I already have that drivers, the w4-657, so what do you think about adding a tweeter to it?
For what? If you mean 'not enough to go down to about 40Hz without major dynamic compression', I completely agree. You'd need a full sized horn to take it down to that frequency without suffering major problems. On the other hand, it's got sufficient linear displacement for other duties; for e.g., if bandwidth limited and / or being used in a small space. So as ever, such things depend on the circumstances.
Neither is any other 'full range' driver, so it's in good company. 😉 They're all better described as wide-band units.
Yes, it's a double mouth horn. I'm not sure I understand what the point you are trying to make here is?
Are you are proposing that someone should compare the measurements of, say, your Kornett to my Saburo box? What value do you believe there would be in doing that? They're completely different enclosure types, they have different numbers of drivers and to cap it all, Saburo is neither designed nor recommended for the FE103E or W4 697.
Morpheus -FWIW, I do have something which might be of interest to you -if you wanted to give it a try, give me a shout at my FH email.
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Hi Scott, you're right, i think the enclosure will fit better is the Aiko, considering the parameters of the w4 are more similar to the fe108.
So, do you think the aiko can fit?Or better to try some modifications?
I tried to calculate the throat area, seems that the Aiko has 41cm2, while the w4 will require 26cm2...maybe i can try adapting it...with some help...😉
Hello,
i would try the W4 at 4kHz 6 dB and tweeter 6 kHz 6 db.
Hi scott,
"let you show measurements, IMP and membranmovement and compair it."
show us and you will see, the developer must have this data,
if not everyone can think about.
I can interpret the data.
i would try the W4 at 4kHz 6 dB and tweeter 6 kHz 6 db.
Hi scott,
"let you show measurements, IMP and membranmovement and compair it."
show us and you will see, the developer must have this data,
if not everyone can think about.
I can interpret the data.
For the second time:
1/ Saburo is not designed for the FE103E (or similar drivers)
2/ It is tuned too low for such drivers
3/ It is not now, and never has been suggested for such drivers.
Oddly enough, given these minor details 😉 I have no measurements of the FE103E or a similar unit in the Saburo enclosure. I can tell you right now what the results would be though: poor.
More generally, there is a fairly important point to be raised here, which is that attempting to compare between speakers, even when they are using the same (let alone the same number of!) drive units, is meaningless unless they were designed to exactly the same criteria. Horst had a specific purpose in mind when he designed his Kornett box; I had a different one with Saburo. Take dispersion. The Kornett's relatively small termini are directed sideways, rather than at the listener; its radiation pattern when combined with the twin-driver layout will be quasi-omnidirectional. Conversely, Saburo, with its larger termini area and their forward-firing, over-under configuration gives a more constant acoustical size and greater vertical directivity. Another example? Oh, go on then. Horst clearly focused on dynamic bandwidth with the Kornett; that was not a priority with the Saburo design. We could continue, but there would be little purpose; I think the point is obvious enough, viz. name your poison: http://www.youtube.com/watch?v=wcRSwo9bGHQ
1/ Saburo is not designed for the FE103E (or similar drivers)
2/ It is tuned too low for such drivers
3/ It is not now, and never has been suggested for such drivers.
Oddly enough, given these minor details 😉 I have no measurements of the FE103E or a similar unit in the Saburo enclosure. I can tell you right now what the results would be though: poor.
More generally, there is a fairly important point to be raised here, which is that attempting to compare between speakers, even when they are using the same (let alone the same number of!) drive units, is meaningless unless they were designed to exactly the same criteria. Horst had a specific purpose in mind when he designed his Kornett box; I had a different one with Saburo. Take dispersion. The Kornett's relatively small termini are directed sideways, rather than at the listener; its radiation pattern when combined with the twin-driver layout will be quasi-omnidirectional. Conversely, Saburo, with its larger termini area and their forward-firing, over-under configuration gives a more constant acoustical size and greater vertical directivity. Another example? Oh, go on then. Horst clearly focused on dynamic bandwidth with the Kornett; that was not a priority with the Saburo design. We could continue, but there would be little purpose; I think the point is obvious enough, viz. name your poison: http://www.youtube.com/watch?v=wcRSwo9bGHQ
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I believe Dave tried it recently with the pair of Aiko's they built at that end with good results. Aiko is tuned ~an octave above the Saburo family & will have rather better power-handling. I wasn't thinking of that box as it happens, but it will certainly be a better bet than Saburo.
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Thanks a lot Scott,
just one question, what about the throat area?
The aiko has a bigger throat area compared with the one requested from the w4-657(41 vs 26 cm2) from my calculations.
Do you think I have to modify it or it can fit? Which parameters can be affected from this difference?
I have FE103A in Aiko at the moment, and it is the best i've heard them -- and that with some undone tweaking to properly fit them. If you go ahead i'd start out with a larger air cavity, and fill as needed.
dave
Fine, this means probably it will fit nicely also my w4...
My only concern now is about the high freq response:
Quite bad over 15kHz...I though about putting an optional tweeter on the suprabaffle. I have these lying aorund my garage:
Proaudio Hi-Fi
Regarding throat areas, it depends on how you calculated it, i.e. which assumptions were involved in the math. Taken purely by itself, the larger the throat, the lower the cut off.
You could add a tweeter -suck it & see basically, if you feel the need, go for it.
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I'd not worry about it too much to start. Then, if you find you need a little more sparkle at the top, a simple cap on the tweeter you've linked should give you that.
dave
dave
Well, referring to this formula:
The throat size is only related with the driver specs, not the cutoff frequency.
But I don't know what really happens if the throat area is smaller than the one derived from calculations.
An externally hosted image should be here but it was not working when we last tested it.
The throat size is only related with the driver specs, not the cutoff frequency.
But I don't know what really happens if the throat area is smaller than the one derived from calculations.
They are optimizing for something there (bandwidth or efficiency likely) and living with whatever cut-off falls out.
dave
dave
Probably this throat area has something to do with efficiency, but don't know.
From the formulas, the cut off is mostly determined by the mouth area:
Even if it is also related to the rear chamber volume.
From the formulas, the cut off is mostly determined by the mouth area:
An externally hosted image should be here but it was not working when we last tested it.
Even if it is also related to the rear chamber volume.
Those two sizing formulas are a starting point but obviously they can't combine all the variables into one system.
It's faster to sim to get the total system response, then iterate various parameters. If you read MJK, you'll see that the math turns out to be complex (way too complex for me, anyway).
At least in a simulation tool, you can juggle all the variables to see that one tweak gives you more gain, but at the cost of bandwidth, or flatness etc. It's like trying to hit a bullet with another bullet. (Well worth the effort, though.)
It's faster to sim to get the total system response, then iterate various parameters. If you read MJK, you'll see that the math turns out to be complex (way too complex for me, anyway).
At least in a simulation tool, you can juggle all the variables to see that one tweak gives you more gain, but at the cost of bandwidth, or flatness etc. It's like trying to hit a bullet with another bullet. (Well worth the effort, though.)
Throat size is not a function of driver specification per se. A horn is designed by establishing a desired gain bandwidth (BW), with lower and upper corner frequencies (Fl and Fh respectively). These define the throat and mouth areas, with length being a function of the selected expansion profile. Where driver specifications come in is in establishing the optimal dimensions to achieve the desired results (whatever they happen to be) with that particular unit.
Well, the only formulas I've found are the ones I posted, so if I'd like to design my own horn, where should I begin?
I thought I had something where to start from, but it seems I'm wrong...
I thought I had something where to start from, but it seems I'm wrong...
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