| kvk |
So I'm still looking at all these plans trying to decide what to build. I still am considering the Fonken Floorstander and the Meliva but I also think taper pipes are so cool looking and look very easy to build.
I've googled fe127e and a bunch of things and can only find folded pipe designs.
Anyone know of an unfolded pipe design for it or similar driver (that's still made; there's tons of plans online of RatShack drivers no longer made) a MLTL or TQWP kinda of enclosure.
I looked at this page--
https://mywebspace.wisc.edu/jstalna...eSpeakers/#TQWT
but the small designs are for that RatShack driver.
I image allow I really need to know is how the calculate the length, the base area, and the area of the port. Anyone have a spreadsheet for that? I found the one for the BIB and one for folded pipes but not straight. |
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| kvk |
Would mechanically BSC with one of those disk things be effective enough? I think they are kinda cool looking. Or would it just push the point down but not enough? |
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| GM |
It will if it's ~8 ft square. ;) You will need one of the high gain BLHs to offset the LF/mid-bass/lower mids loss if not built into a wall. Then again, these little drivers by themselves really should only be critically listened to either up close and/or in a small room when tuned below ~1.6*Fs as they rapidly begin sounding 'congested' due to their low Xmax, so depending on the driver's HF response in these situations they may not need any BSC.
GM |
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| SCD |
Here is a picture of an interesting project I made a few years ago. They are bipoles. I quite like the sound of them. The new owner seems quite happy with them.
If you are interested I am sure dave could send you the design. |
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| kvk |
| quote: | Originally posted by GM
It will if it's ~8 ft square. ;)
GM |
Do you mean 8'x8' or 8'^2 ?
8'^2 would only be a disk with R=1.77'. Two small round kitchen table-tops should do. :D |
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| kvk |
Were the removable baffles just to swap drivers or do the server some other purpose?
Like maybe providing bigger wholes to tune stuffing? |
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| chrisb |
| quote: | Originally posted by SCD
Here is a picture of an interesting project I made a few years ago. They are bipoles. I quite like the sound of them. The new owner seems quite happy with them.
If you are interested I am sure dave could send you the design. |
Scott's bipole Voigt pipe did sound quite fine indeed, although Dave might suggest some minor refinement to details.
There were a pair of bipole metronomes with Hemp FR4.5 played at a DIY party last year that sounded spectacular.
One other class of very easy to build enclosure that works well with the FE127E is the BIB. Although as a crude BLH, it requires corner boundary loading, and since it's fairly narrow for this driver, a suprabaffle, or BSC filter.
The Mileva is a pretty darned easy build as well, and with the wide baffle and shallow depth allowing for close wall mounting, baffle step loss is far less of an issue. |
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| chrisb |
| quote: | Originally posted by kvk
Were the removable baffles just to swap drivers or do the server some other purpose?
Like maybe providing bigger wholes to tune stuffing? |
I think the former, as the original occupants of the cabinets were the larger RS40-1354 - although if such a removable baffle was sealed with a airtight gasket, you could achieve some degree of the latter as well. |
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| Godzilla |
>>> Were the removable baffles just to swap drivers...
Yes. I find pipes to be forgiving cabinets that work well with many different drivers. Basically, i built these originally for the RS 1354 drivers but wanted more detail. I found the 127e to be a nice upgrade. Subjectively, bass went deeper and was more detailed tho the overall presentation was more forward. I am thinking of swapping drivers again and using the older fostex 168s in the straight pipes. Again, not the perfect cabinet for this driver - i enjoy swapping drivers to get a sense of their sound - sort of like tube rolling. There are better cabs more optimized for the 127e if that is your choice. Meliva and some ported boxes. A BIB would probably work great but they do look like simple (elegant) cabinets. The sloped back baffle does look great and everyone always runs their fingers across it. They look very hi-end. I would consider building one of the smaller, more optimized sloped back pipes for the 127e - stick them into corners for bass support or add a powered sub. They light up the room with sound in a nice way but they do become congested on loud music and they are light in bass. Currently i am enjoying them in the cabinets in the link below.
http://www.zillaspeak.com/fostex127eSSB.asp
And of course, here is a fantastic resource regarding the 127e and other drivers.
http://www.frugal-horn.com/index.html
Godzilla |
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| kvk |
Darn, that looks easy. The comments say you shrunk the dims to fit. I looked at that thread but it's a bazillion pages long and could not find the original reference design. Can you point me in the direction of the optimum dims?
I have some reclaimed pine from some 40-yo bedroom closet shelves I took out. Nice patina and don't have to worry about warping /splitting from using new wood. If they're not more than 11.5" wide, I could get some nice stained fronts. |
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| chrisb |
| quote: | Originally posted by kvk
Darn, that looks easy. The comments say you shrunk the dims to fit. I looked at that thread but it's a bazillion pages long and could not find the original reference design. Can you point me in the direction of the optimum dims?
I have some reclaimed pine from some 40-yo bedroom closet shelves I took out. Nice patina and don't have to worry about warping /splitting from using new wood. If they're not more than 11.5" wide, I could get some nice stained fronts. |
Dimensions as built:
I think that DaveD has a drawing for this cabinet as well - I seem to recall cutting out parts for a flat-pak of this design a year or so ago, but can't remember the exact dimensions.
If I may, I'd suggest two details not shown in the pictures - a brace from the back of the driver magnet to the rear panel (could be a simple as a short piece of 3/4" x 3" stock), and 45dg chamfer to the backside of driver cut-out. |
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| loninappleton |
I've got a Harvey up and running and still doing listening tests on that.
For the builds described and your materials on hand I would go with GMs MLTL and shown by Godzilla to get a fell for what the 127e can do.
But I'm posting here thinking of some variations to optimize the design.
This has to do with ports.
The Zilla design has side firing ports. No combining the current thread on square vs round ports, what would be the optimal tube style port and placement on the side and as close to ear level as makes sense?
The port sound radiates on the same plane as the terminus and so
radiated sound would be going more towards the ear. A cylinder seems to be the ideal shape for this rather than a port cutout.
But I've always liked the MLTL version as a reference. BIB's and Harveys can do more embellishments of sound but the MLTL is the most instrumental I've built. So I'm wondering if there are additional tweaks to make a new set. |
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| chrisb |
FWIW, this came up in a conversation just last weekend - it's almost as hard to get a bad sounding enclosure for the FE127E, as it is to get agreement on how to derive the best of the FE126E. |
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| chrisb |
| quote: | Originally posted by loninappleton
I've got a Harvey up and running and still doing listening tests on that.
For the builds described and your materials on hand I would go with GMs MLTL and shown by Godzilla to get a fell for what the 127e can do.
But I'm posting here thinking of some variations to optimize the design.
This has to do with ports.
The Zilla design has side firing ports. No combining the current thread on square vs round ports, what would be the optimal tube style port and placement on the side and as close to ear level as makes sense?
The port sound radiates on the same plane as the terminus and so
radiated sound would be going more towards the ear. A cylinder seems to be the ideal shape for this rather than a port cutout.
But I've always liked the MLTL version as a reference. BIB's and Harveys can do more embellishments of sound but the MLTL is the most instrumental I've built. So I'm wondering if there are additional tweaks to make a new set. |
Lon - the Tom Z PAWO (somewhat similar to the Jordan VTL design, with a side firing ports - I built them as mirror imaged pairs) and more recently the Mileva (folded ML Voigt pipe with a front slot terminus loaded at the floor that adds flexibility to room placement) are also worthy of consideration.
It's hard to keep track of all the projects the seriously addicted builders have played with - have you experimented with either of those? |
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| loninappleton |
| quote: | Originally posted by chrisb
Lon - the Tom Z PAWO (somewhat similar to the Jordan VTL design, with a side firing ports - I built them as mirror imaged pairs) and more recently the Mileva (folded ML Voigt pipe with a front slot terminus loaded at the floor that adds flexibility to room placement) are also worthy of consideration.
It's hard to keep track of all the projects the seriously addicted builders have played with - have you experimented with either of those? |
I have my eye on the Mileva and looked at the PAWO labyrinth design
for some time but never executed it.
The idea I have at the moment is to modify the design of the GM MLTL I'm using. This takes a bit of explanation: The dimensions are the exact ones given by GM. But I made a down firing port 2 in. standard pvc x 4 in long projecting out the bottom. The stand holding this has a hole cut in it for the port and is open on 2 sides.
What I could do with one or both to move the physical location of the port to the side would be to simply plug up the bottom and use an elbow joint inside the box to get the right length. Then comes the issue of positioning the cutout. I don't believe that specialized flared ports are beneficial. The goal is to get the port terminus action closer to ear level.
A question I have with this is what effect does the side flush to the port have as opposed to the 'free air' down firing jobbie I have now (?)
That's what keeps the hobby going.
:cool: |
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| Godzilla |
>>> The goal is to get the port terminus action closer to ear level.
Why not simply flip it over? |
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| loninappleton |
| quote: | Originally posted by Godzilla
>>> The goal is to get the port terminus action closer to ear level.
Why not simply flip it over? |
Curiously I did that with a Tangband W821s (whatevs.) It seemed to work well. but I still didn't like the Tangbands. anybody wants to buy 'em for cost and shipping can have them
This opens the question of a passive radiator which is usually used with larger speaks. Like Schultz, "I know nothing" of passive radiators. But I don't suppose the mass loading of the MLTL is effected by gravity with the flip.
Right side up or upside down, the terminus is still in a different plane
and not as close to ear level.
And if there is a boundary from a tv stand or the like, maybe the effect would be enhanced. I'm not even sure what the effect is at this point. Just thinking out loud. |
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| planet10 |
| quote: | Originally posted by SCD
Here is a picture of an interesting project I made a few years ago. They are bipoles. I quite like the sound of them. The new owner seems quite happy with them.
If you are interested I am sure dave could send you the design. |
All EnaBLed up, Scott's bipoles replaced a set of Magnepans. He likes the pipes a lot better.
dave |
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| GM |
| quote: | Originally posted by loninappleton
The dimensions are the exact ones given by GM. But I made a down firing port 2 in. standard pvc x 4 in long projecting out the bottom.
The goal is to get the port terminus action closer to ear level.
A question I have with this is what effect does the side flush to the port have as opposed to the 'free air' down firing jobbie I have now (?) |
Hmm, according to my notes it's a 6" long vent. Regardless, raising the vent up to the driver midpoint will raise Fb a bit, flattening the response some and 'sharpen' the vent's response plus increase its harmonics' effect on the ~300 Hz - up BW, so technically increasing harmonic distortion.
It changes the vent's end correction factor, ergo its tuning frequency, but on such a small vent it's negligible/inaudible.
GM |
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| loninappleton |
| quote: | Originally posted by GM
Hmm, according to my notes it's a 6" long vent. Regardless, raising the vent up to the driver midpoint will raise Fb a bit, flattening the response some and 'sharpen' the vent's response plus increase its harmonics' effect on the ~300 Hz - up BW, so technically increasing harmonic distortion.
It changes the vent's end correction factor, ergo its tuning frequency, but on such a small vent it's negligible/inaudible.
GM |
I don't think I'd raise it up to driver midpoint but get it off the bottom and use an elbow inside the confined space. The reason for the bottom install was to have the full cavity available for loading. I never play anything loud so I don't know if that's just my sense of proportion or what. |
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| GM |
Hmm, not sure why it's this low on a straight pipe, I calc ~11.09" i.d. down from the top for smoothest response with least stuffing. Regardless, when the driver's at the top and vent at the bottom you get max pipe loading that often results in some peaking at Fp, though it can be damped down with additional stuffing if desired and as the driver moves down the pipe the vent loading is reduced until you reach a point of causing severe notching in the response due to the long reflections back to the top of the pipe.
If you want the driver at the top, then move the vent up to smooth it out and increase the vent length to lower Fp back to where you want it and damp any Fp peaking at the vent.
GM |
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| chrisb |
As best as I can recall, there were quite a few variations theorized and drawn during this cooperative project, not all of which were necessarily built - this might well be one of them.
I've frequently opined that while it takes a bit of work to get the most from the FE127E, it's hard to make them sound crummy. Designs like this might fit into that latter category. |
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| Bluto |
I'm thinkin the Guy had computer speakers in mind.
Bluto |
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| edgebc |
GM: I've put off building metronomes or straight thin boxes for my 127s because I need the drivers to be 48" off the floor and the top of the cabinet to be "not a great deal higher". How close to the top dare I put them, is straight sided better at the top because of more volume, and what port adjustment would I make?
Oh, what the hell, recommend dimensions. Thanks. |
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| edgebc |
| Oh, forgot to ask, what is Fp. Thanks again. |
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| Scottmoose |
| Fp = pipe tuning frequency. |
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| planet10 |
| quote: | Originally posted by GM
[B]Hmm, not sure why it's this low on a straight pipe, I calc ~11.09" i.d. down from the top for smoothest response with least stuffing. |
Tim Forman's design. he chose midpoint on a few designs. We need to getthe above note into the diyA FR Ref thread. That offset sure would make for a more conveiient build.
dave |
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| GM |
| quote: | Originally posted by edgebc
GM: How close to the top dare I put them, is straight sided better at the top because of more volume, and what port adjustment would I make?
Oh, what the hell, recommend dimensions. Thanks. |
Well, you can put the driver at the extreme top if you like, it just may require more stuffing than if located further down. Anyway, driver location at the top works best with a high aspect ratio TQWT (reverse taper) and slides down as it shifts to straight, then to horn taper. Another thing to consider is the driver's Qts. For the TQWT we want a relatively low Qts, increasing with increasing flare with straight taper being around 0.4 Qts. Obviously, any flare can be used with any reasonable Qts, just there seems a synergy of sorts using these rules-of-thumb (ROT).
WRT the FE127E, its highish Qts would require a horn flare, ergo lower driver location, so the ROTs won't work here and a MLTL this long for such a small Vas driver poses some problems, but this doesn't look too bad once EQ'd if the published specs are reasonably close:
L = 49.5"
W x D = 7.312" x 4.5"
zdriver = near/at the top
zport = 35.125"
port = 2" dia. x 1.75"
All dims i.d. and stuff as required down to just above the vent (0.25 lbs/ft^3 shown).
GM |
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| GM |
| quote: | Originally posted by planet10
We need to getthe above note into the diyA FR Ref thread. That offset sure would make for a more conveiient build. |
?? Assuming TF doesn't mind, seems like it should be listed as a note on the drawing as an alternate driver location.
GM |
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| planet10 |
| quote: | Originally posted by GM
?? Assuming TF doesn't mind, seems like it should be listed as a note on the drawing as an alternate driver location.
GM |
Acyually i'd planned a whole new drawing with the option. I know Tim won't mind.
dave |
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| edgebc |
Clarification please, sorry.........
Is the port 35" down from the center of the driver, the top or 35 " up from the bottom?
Would a reverse taper(behind the driver) stuffed trap, like in the BiB, help? |
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| GM |
Down from the top (or more technically correct, the closed end) since this is the way MJK's worksheets calculate pipe action.
?? The BIB is a pipe horn, i.e. expanding, not TQWT (contracting).
GM |
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