| SunRa |
Hello Xor,
now, how is your cabinet handelling different kinds of music. For example I guess it's great for vocal (tori amos, loreen mckennit), for acoustic (clapton, paco de lucia) but how about something more demanding like some classic rock (led zepelin, deep purple)? Do you think that by simply adding a sub (and cutting them at let's say 80Hz down) would give me the posibility to listen this kind of music with out loosing the qualitty?
Regards, Florin |
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| eLarson |
| Yes, birch is the correct term in English. It looks to be a nice match for your Poäng arm chair, too. :) |
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| SCD |
Cabinet bracing:
We have been longitudinally bracing our cabinets for a while now. It takes a bit more effort and a bit of volume adjustment but it is really worth the time it takes. I cut a 1/4 inch deep chanel down the inside length of the sides. NOT centred on the panel. The width of the channel is to accept a piece of sheet material as a brace either 3/8 or 1/2 inch thick plywood.The brace is drilled with lots of difering size large holes in a random type pattern. The holes are 1 inch through 3 inch diameter. The brace is cut out to accept the depth of drivers exactly.
The concept is to reinforce the panels and reduce the resonant surface so the frequency of resonance is above the audio range. Coupling the drivers also reduces driver basket resonance. When completed the cabinets should be very solid and resonace from the components should not contribute to the sound.
Sub integration:
I have been experimenting with the concept you are describing and I think it works quite well. The caveat is that you must remember you are using a 4 inch driver that excels at mid range not bass. If you want to listen at normal to not too loud levels yes it works. If you want to listen with your hair straight back well this might not be the best choice for you. If you can do it two subs are even better.
Nuff said for now |
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| westend |
| quote: | Originally posted by Xor
Thank you. My GFs first comment when she saw them was: now you have to build a new tv and stereo bench.. So lessond learned: dont make it to fancy.. ;)
I find they have supprisingly good bottom.. I think my neighbours are quite happy without a sub accually ;)
I cant wait for them to break in, I cant really imagen what they will sound like then.
Thanks a bunch for this tread and all info! |
Here's the real lesson: now you can build the stereo bench/rack to hold all your FUTURE audio purchases. She can't complain because it was HER idea.
:) |
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| Xor |
| quote: | Originally posted by westend
Here's the real lesson: now you can build the stereo bench/rack to hold all your FUTURE audio purchases. She can't complain because it was HER idea.
:) |
Hehe.. thats true.. well time to buy some more wood then :) |
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| planet10 |
| quote: | Originally posted by SCD
NOT centred on the panel. |
:^)
You wouldn't believe Scot's consternation when he was 1st presented with that gem....
dave |
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| Ray Collins |
| Of the three refrence designs developed on this thread which, if any of them, would be optimal for a home theater in an intimate setting, ie, a 13' x 14' room? |
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| Xor |
Im have a question about stuffing again
I now have lined the walls of the whole speaker with pollyfluff..
Is there suppose to be something in between the drivers? Now I only have the coupling rod. Do I gain anything with stuffing there? And If so, how should I apply it?
The speaker is playing nicely, but everything can be tweeked.. ;) |
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| planet10 |
| quote: | Originally posted by Ray Collins
Of the three refrence designs developed on this thread which, if any of them, would be optimal for a home theater in an intimate setting, ie, a 13' x 14' room? |
The versions with more drivers are probably more suited to the typical levels used by HT...
dave |
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| planet10 |
| quote: | Originally posted by Xor
I now have lined the walls of the whole speaker with pollyfluff.. |
Stuffing should start out at least uniformly distributed thru-out the line.
dave |
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| Ray Collins |
| Thanks for the response Dave. I should have been more specific with my request for a recommendation. We, my wife and I, do not use high volume levels when watching movies. The primary interest is accuracy at moderate to mid volume levels. There is no interest in pants flapping, bone jaring LFE either. I know this is home theater heresy but I can neither tolerate the bass rolling toward me like a sea of mud nor everything blaring away in a obfuscated cacophony. Cohesive, crisp, unveiled sound is the primary interest along with the ability to distinguish the nuance of dialog, movement etc. occuring during the movie. |
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| planet10 |
| quote: | Originally posted by Ray Collins
Thanks for the response Dave. I should have been more specific with my request for a recommendation. We, my wife and I, do not use high volume levels when watching movies. The primary interest is accuracy at moderate to mid volume levels. There is no interest in pants flapping, bone jaring LFE either. I know this is home theater heresy but I can neither tolerate the bass rolling toward me like a sea of mud nor everything blaring away in a obfuscated cacophony. Cohesive, crisp, unveiled sound is the primary interest along with the ability to distinguish the nuance of dialog, movement etc. occuring during the movie. |
Then whichever one you'd like... they are all good.
But IMHO the Fonken is better than either (i'm predudiced of course and we haven't done the BiFonken yet)
dave |
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| Xor |
| quote: | Originally posted by planet10
Stuffing should start out at least uniformly distributed thru-out the line.
dave |
So you mean I need to fill the middle with pollyfluff aswell I suppose? |
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| planet10 |
| quote: | Originally posted by Xor
So you mean I need to fill the middle with pollyfluff aswell I suppose? |
yes |
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| Xor |
| quote: | Originally posted by planet10
yes |
So.. I lined the sides with this stuff: http://www.biltema.se/products/prod...4&iItemId=78464
And its 0.58m2 * 300g = 174g. How much normal polyfluff should I have as a start-value for the middle of the line? Or should I somehow reduce the amount of lining?
How should the sound change when the whole line is stuffed instead of just lined?
Thankfull for you answering my stupid questions once again (but at least im learning:)) |
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| rabbitz |
I tried the FE127E in a small TL design that I found and it was a bit lifeless for my tastes plus the bass performance was lacking.
With that experiment over I ended up designing a small 12.5 litre vented box and have it listed on my site. The speaker is very open, lively with a surprising bass performance and needed BSC to bring out the best, even though it was wall loaded.
Details of the design can be found here.here |
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| SCD |
Hello rabbitZ
Was the TL design one of the ones on this thread?
If you get a chance a bipole is great with this driver |
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| rabbitz |
Hi SCD
I won't say what the design was as it could have been my implementation, not getting the stuffing right or the sound may just have not been to my tastes and that is not the fault of any design. My forte is not in TL's so am limited in my tweaking ability and unless you understand the full design process, it's hard to make changes to suit. Vented and sealed are my background, so that's the path I took as I can wring the best out of a design using those as I completely understand them.
What I will say is that I normally don't delve into fullrange but heard a Visaton B200 in an OB and was very impressed so wanted to try one of the Fostex drivers as I have always wanted to know what the fuss was all about and been busting to try one. This thread gave me the the push I needed.
The best driver for my application was the FE127E. The choice was spot on and used within it's limitations, right location and partnering equipment is very special indeed. Sure, the top end is not the best I've heard and the bass is limited in depth (goes low enough to make the foot tap however), but that's not the point, as this driver when done right is extremely musical and has a great presentation. I'm extremely happy with the outcome and have a big grin when listening.
If anyone thinks a fullrange design is easy as it's only one driver is fooling themselves as the box needs to be right, getting the box proportions right to help with standing waves, right amount of damping and to deal with baffle step and the rising response takes a bit of work. If not done correctly the speaker will sound top and upper mid heavy but get it right and it's mmmmmmm, yummy. Well worth playing with and choose the right driver for the job and you're half way there.
I imagine the bipole would be great but this speaker was to be used in a small location and close to the back wall... all about designing to suit the application.
Another convert is born ;) |
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| jrosenth |
This is my first post here - a great site and great thread for a nonvice such as myself.
Basically I'm interested in doing a wedge or slanted bi-pole similar to what SCD did:
http://www.diyaudio.com/forums/show...0&pagenumber=45
How would I go about getting the dimensions?
Thanks in advance. |
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| planet10 |
| quote: | Originally posted by jrosenth
How would I go about getting the dimensions? |
The amount of lean-back is dependent on the listening height of your ears, the distance you are from the speakers, and the height of the driver above the floor.
In the example below, lets 1st assume we want to be on axis (sometimes off axis is good to tame a rising hi-end), that the listening distance is 8 ft, your ears are 36" above the floor and the driver centre is 17 1/2" up (i've added a 3/4" base to keep the speaker from tipping).
Draw a line from Point A (speaker) to point B (your ears). A perpendicular to this line is the slope of the front baffle.
Note that a higher stand (for instance required if you port out the bottom) will mean less lean-back.
dave |
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| planet10 |
| And here is the speaker you get for the above scenerio.... |
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| Brent Welke |
| Ah....nice. I can see a pair of these in my near future :) |
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| jrosenth |
Thanks Dave - that's great.
I think that I'll either build that or try and figure out a way to to a bi-pole of Tim's little gem:
http://www.pi.alegriaaudio.com/FQ127.htm
Again, great site - this thread is a real service and speaks volumes about this community. |
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| planet10 |
| quote: | Originally posted by jrosenth
figure out a way to to a bi-pole of Tim's little gem FQ127.htm |
Double the cross-section area & the number of ports (or figure a single one of equivalent effect)
The only way of doing that and keeping the same aspect is to double the width (below is the above distance analysis for the FQ127 -- an on-axis listening distance of just over 6 ft, quite a bit more latitude if you are happy with +/- 10 degrees.
It should also be noted that the original FQ127 cabinet was the now famous RS 40-1197 bipole, so you might well consider trying to find some 1197s or even just install a pair of FE103 in the FQ127.
dave |
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| jrosenth |
That almost seems to easy so I'm certain that I'm misunderstanding :)
Do I simply take that design and:
1) double the internal width
2) add a second port of the same size next to the original port
3) add a second 127FE on the back of the cabinet at the same height as the driver on the front
4) connect the backs of the two drivers with a dowel (admittedly may take a little playing around to get the angle)
Also, where could I find the plans for the "original FQ 127" if I did just go with the 103?
Thanks. |
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| jrosenth |
Thanks Tim - I think I follow now.
Also, red is a great color for these. I was toying with the idea of doing red or blue, maybe even green stain but wasn't certain how it would look (think WAF). After seeing those, I think that I'll go for it. |
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| SCD |
Well did someone ask about my favourite creation.
Attached is a photo of this little gem. I do not have my detailed construction notes handy so I will have to just use the rough data to start.
This is the design I was suposed to use:So=6.5, Sl=65 L=42, 1" port out the bottom. 1.5 inch legs. Line the inside with wool felt. Vertical brace just off centre.(needs side bracing as well). Couple drivers.
I use real wood if that is not available I highly recommend Baltic Birch plywood rather than MDF.
use three legs.
I have not tried it yet but I think Daves latest mod to the driver will be very good in this design.
Good luck keep us in the loop |
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| Timn8ter |
Thanks Scott, although, I think you can drop the photo special effects.
;) |
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| SCD |
Sorry about that
I suppose not everybody is comfortable with inverted colours!
Here is a more normal look |
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| RKH |
Appologies if these have been discussed but I've not found the answers skimming the thread
1. What is the best method for bracing between the back end of the drivers in a bipole configuration? Is it simply a matter of a press fit brace between the two or is the bracing somehow attached to the rear of the drivers?
2. Are the drivers wired in series or parallel?
Thanks very much
Ryan |
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| Harderror |
| Sorry if this has been asked. However, I want to know if the Fonken design will lend itself well to the fostex fe126e as well? Anyone have any thoughts on this? I am currently building modified Buschhorn Mark II's and want to try these drivers in other types of boxes. What I assume is that this driver works best in BLH designs, but, I am extremely curious about the Fonke design. Any thoughts would be appreciated. |
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| SCD |
Hello Ryan:
Planet10 did drawings for the WR125 bipole on his in the box plan library. This shows a very good example of bracing for both the driver and the cabinet. I have used this process with great success. If you want to get real fussy you can increase the internal crosssection by approx the amount of the bracing. I like to use either 1/2 or 3/8 inch plywood for this.
I cut a stopped dato in the back of the baffles to locate the brace. You could also use a biscuit joiner to do the same thing.
Temporarily mount the driver on the baffle to get the correct sizing for the cut out. Use duct seal to bind the driver to the brace once cabinet is complete. Makes a fantastic difference.
Hope this helps
Good luck |
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| planet10 |
| quote: | Originally posted by Harderror
I want to know if the Fonken design will lend itself well to the fostex fe126e as well? |
Tried that. No it doesn't work. To get real bass out of the 126 really requires a horn. I'd suggest the RonHorn A126 or the Frugel-Horn (it is a moving target thou).
dave |
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| planet10 |
| quote: | Originally posted by SCD
Planet10 did drawings for the WR125 bipole on his in the box plan library. |
http://www.planet10-hifi.com/boxes.html
Most of the bipoles in the box-pan library show this technique. A step further along is to use ready rod instead of screws to hold the driver in. MaxRo did one where he floated the driver on the baffle (ie the driver not coupled to the baffles, only to the brace & each other), integrating the baffle into the mix means having access to the inside of the box to tighten the nuts on the inside of the box... an idea of that can be seen here
dave |
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| chrisb |
| quote: | Originally posted by RKH
Appologies if these have been discussed but I've not found the answers skimming the thread
1. What is the best method for bracing between the back end of the drivers in a bipole configuration? Is it simply a matter of a press fit brace between the two or is the bracing somehow attached to the rear of the drivers?
2. Are the drivers wired in series or parallel?
Thanks very much
Ryan |
your first question has been answered, but as to #2 - that probably depends on the synergy with your amp.
one of the project P/P tube amps we're using has 4/8&16 ohm taps, so it's not an issue, but in the case of amps with single tap only (or SS), I usually use a biwire terminal plate to allow for easy switch from S to P. |
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| Harderror |
Thanks Dave! Before I read your reply I threw together a set today. The picture doesn's do them justice. I still need to clean excess glue off and trim the bottoms and tops before I damp and seal them. I am going to try throwing the 126's in there tomorrow just for giggles. I suppose I will order a set of 127's in the next couple of weeks. That is of course unless someone would suggest a better driver for these enclosures? I like Fostex though.
Just to cover how I built these. No screws, all glue. I made all the outside panels 19mm instead of the 1/2 inch that was called for. All interior dimesions are the same as what the planet 10 plans called for. I used MDF of course, as these are more of an experiment than anything. I also, I believe that I altered the plan a bit in that I mad the top and bottom panels the last thing to be attached. I like this way of working and it allows easy access if I need to go in to tweek anything. Now that I know that I will need different drivers, I am dying with anticipation as to what these beautiful boxes will sound like. Has anyone else built these? Any comments on how they sound? I became interested in the Onken design some time ago and was pleased to find this plan on the Planet 10 web site. Any feedback on these would be appreciated! |
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| GG |
| quote: | Originally posted by Harderror
Any feedback on these would be appreciated! |
These 4.5" drivers don't have much room behind them, so champfer out behind the driver to give them some room to breath.
Cheers,
Gio. |
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| GG |
The picture below shows a champfer for an FE127E bi-pole I am working on. The router work was done by my friend Mark.
Since you already have the baffle on, you may have to do something along the lines of what I had to do with my BD-Pipes.
http://www.diyaudio.com/forums/show...8967#post808967
Good luck,
Gio. |
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| Harderror |
I don't think you can see it in the photo but I did a pretty heavy roundover on the edge. Anymore and I am worried that I won't be able to screw in the screws for the driver. I suppose though that I need to get as much room as possible right? maybe I can take somemore off. I didn't think of doing it liike you show in your photo there though. Hmm, nice work.
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| TerryO |
| quote: | Originally posted by Harderror
Any comments on how they sound? I became interested in the Onken design some time ago and was pleased to find this plan on the Planet 10 web site. Any feedback on these would be appreciated! |
I heard Dave's pair at the last RAW event, and I thought that they were perhaps the best allround speakers there (with the exception of mine, of course! :^)
I think that you will be more than a little pleased with the end result, the only problem with the Fonkens is, IMHO, where do you go from there? It's something like Alexander's complaint that his father had been so successful that there wouldn't be any kingdoms left to conquer.
The use of 3/4 inch for the side panels is perhaps overkill, but it shouldn't cause any negative contributions, and it may help. I'm prone to heavy construction myself and would have done the same thing.
What are your plans for finishing them? They look pretty darn nice, I wish my efforts turned out as well as yours have.
Best Regards,
TerryO |
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| planet10 |
Chris routes the back edges off at 45 degrees all the way round on ours (we are using plywood thou)....
As i privately noted to Terry earlier, treating the FE127 cones turned -- IMHO -- the Fonkens from good to spectacular... speaking of which time to get the protos back from Chris.
It will be interesting to see how the MDF does...
For reference we get the 45 on the front ports by running the whole box thru the table saw after the box is built.
dave |
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| Harderror |
As backwards as it sounds. I didn't actually do that. I cut and glued mine at 45. Probably much much easier your way. I don't know why I did that. It's funny. I thought of that after they were built saying to myself "Tom, why didn't you just glue them flat and cut the bevel on the front on the saw. Ah well. On the next pair (if I like these), which of course will be baltic birch. Then I can compare the differences.
On a slightly different note. These things are a tedious trial to glue up. The ports are quite the pain if you are only working with 6 clamps. I need to get more clamps. ;)
The aticipation is killing me. I can't wait to get a set of 127's. Cash is not at hand at the moment. ARGH! hehe I can't wait. I think I will throw those crappy pioneers in just to see what they will do in them. |
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| Harderror |
What are your plans for finishing them? They look pretty darn nice, I wish my efforts turned out as well as yours have.
Best Regards,
TerryO
Thank you for the compliment! I am not sure how I will finish them. I still havn't finished a set (out of the six pairs of speakers I have built). I am waiting for the paire that knocks my socks off. In other words, they will have to be speakers that I want to stay in my house. I may just sand seal and black laquer them. They seem to me that they are screaming out to be black laquered. |
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| loninappleton |
Re: finish.
Yes, there's something about the details of an onken
that says black laqueur rather than that truck bed stuff
or other finishes. They'd look like the grille of a ...
what... Prowler.?
;-) |
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| Harderror |
| Well, I got them running (with the wrong driver). I must say though, even with the fe126e in them, they sound very good. Not alot of bass, but enough to listen to until I buy the 127's Here it is with the drivers installed (And clamped closed). I love the sound. It certainly has a certain kind of character to it! Sure am glad I built these on a whim. |
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| RKH |
All,
Thanks for the speedy and thorough replies to my previous post.
Ryan |
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| eforer |
Hi all,
Firstly, I've really enjoyed reading these forums and I am glad that there is so much interest in this hobby. This is my first post, and appropriately its regarding my first DIY project(s).
I am interested in building the latest version of the monopole for my first DIY speaker. I would like to mate it with a modified T-Amp, possibly a DIY paradise charlize based amp. Do you experts think this pairing is suitable? I am also interested in a low power simple tube DIY project, would that be more appropriate and if so do you guys have any suggestions.
I am also interested in the Buschorn MKIIs, the Cyburg Needles or a BIB project. Do you guys feel this project would be a better choice for me than these?
If I opt for the reference monopole (which is what I am leaning toward as it seems this design reflects alot of peoples hard work and research) in addition to the poly fill, should I dampen the cabinet walls with carpet pad or anything like that?
Finally, plywood or MDF? If plywood, baltic birch seems to be favored. Is this the same birch ply availible in construction super stores ie home depot etc?
Sorry for the myriad of questions. I have read through the forums but am still confused on these issues. |
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| chrisb |
| quote: | Originally posted by eforer
Hi all,
Firstly, I've really enjoyed reading these forums and I am glad that there is so much interest in this hobby. This is my first post, and appropriately its regarding my first DIY project(s).
I am interested in building the latest version of the monopole for my first DIY speaker. I would like to mate it with a modified T-Amp, possibly a DIY paradise charlize based amp. Do you experts think this pairing is suitable? I am also interested in a low power simple tube DIY project, would that be more appropriate and if so do you guys have any suggestions.
I am also interested in the Buschorn MKIIs, the Cyburg Needles or a BIB project. Do you guys feel this project would be a better choice for me than these?
If I opt for the reference monopole (which is what I am leaning toward as it seems this design reflects alot of peoples hard work and research) in addition to the poly fill, should I dampen the cabinet walls with carpet pad or anything like that?
Finally, plywood or MDF? If plywood, baltic birch seems to be favored. Is this the same birch ply availible in construction super stores ie home depot etc?
Sorry for the myriad of questions. I have read through the forums but am still confused on these issues. |
If I may make a few suggestions:
The monopole MLTL is a great starter - quite an easy build, and with FE127E's treated per Dave (Planet10)'s formula, an amazing performer - but for this driver quite simply not the same level as the Fonken.
While I can appreciate the combination of "jump factor" and WAF of a small BLH design, (a la Buschorn, etc) as much as anyone, I'd hold off on any type of horn until the ink is dry on the next refinement of the FrugelHorn project (and the glue is dry on our prototypes)
Whichever speakers you build ( oh yes, I have a feeling there will be more than 1 pair ), I would strongly recommend using only baltic birch plywood. While the cut list for the little MLTL's is very small, you'll have lots left over from a 5x5' sheet for the next project.
For many listeners, the Fostex's FE series of drivers are an acquired taste - I think much of the criticism that some have is from a combination of inadequate break-in, room placement issues with horns, and system dissonance. Put simply, the Fostex are far less forgiving of poor quality or mismatched source/amplifier components than some other drivers with which members of this forum are familiar.
Yes, there is a synergy between the FE127 / FE126 and low/moderate powered tube amps - I particularly enjoy the 127Fonken, Frugelhorn and Ron Clarke's A126 with RH84. |
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| chrisb |
| quote: | Originally posted by Harderror
Well, I got them running (with the wrong driver). I must say though, even with the fe126e in them, they sound very good. Not alot of bass, but enough to listen to until I buy the 127's Here it is with the drivers installed (And clamped closed). I love the sound. It certainly has a certain kind of character to it! Sure am glad I built these on a whim. |
Tom: the second pair will probably be a faster build than the first (by the third & latter even faster :D )
You gotta try them in baltic birch; with it's small size and internal bracing, this is quite a stiff little cabinet, and you really can get away with 1/2" material. I'm a big believer in the light and tight school - on a box this small it's relatively easy to get the panel resonances well above the enclosure's tuned resonant frequency, provided you don't overbrace or use thick / massive material.
The only downside to cutting the large front bevel after the box is assembled is the potential for some chipout on the top/bottoms when using plywood. |
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| jrosenth |
I'd like to thank you guys for this project - absolutely ideal for someone like me trying to get me feet wet with an easy build, readily available parts, lower cost, etc.
I am about to build a pair of either the bipoles or monopoles - the tall thin ones here:
http://www.diyaudio.com/forums/atta...tamp=1102456925
Was going to do the bipoles, but since they would be near a wall shared with a neighbor I am now thinking about the monopoles.
I was wondering about the BSC circuit for these - I've read the thread a few times now but can't seem to find what I need.
Is there a schematic (I'm still new to all this so don't do the best with just descriptions of circuits) for a bsc circuit with values for this project?
Thank you very much. |
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| Harderror |
| Ok, guys, my latest toying around, (I was bored today). This is the pioneer A11EC80. SOunded like **** when I first hooked it up. Now, 7 coats of diluted elmers and a phase plug which I manufactured this morning, as well as felt on the back of the magnet and UHU on the frame of the speaker to damp it, it actually sounds resonably nice. We used it in the home theatre tonight in the Fonken boxes and it really integrated well and shined in these enclosures. Not too shabby for an $11.00 driver. Here are a couple of pictures. |
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| jrosenth |
Anyone on the BSC for the 127 monopole?
Any help is greatly appreciated.
Thanks. |
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| swin1 |
Hey everyone, I've just finished my computer speakers, using the Aura NS3 drivers, simple 3 litre sealed enclosure, painted silver to match the screen, and a picture of my gainclone amp, all in all an awesome setup, and enough bass for me for sure!
Cheers
Andrew |
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| westend |
| quote: | Originally posted by rabbitz
Have a look at the baffle step info here as may give you an idea. Would be very close for the one you want to build.
http://www.rzaudio.com/rz52/fe127e.htm |
That's a sweet design and a good looking finish. I would think these would be a great HT sattelite, especially for those with less than powerful 5.1 recievers. |
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| stelleg151 |
Planning to build a pair of the folded monopoles and just got sketchup so decided to practice a bit and came up with this, thought might as well post it.
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| angchuck |
Looks like the fostex recommended BR with the port to the rear.
Chuck |
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| Godzilla |
Thanks angchuck! I think you meant the recommended double bass reflex enclosure with somewhat modified dims... and the port on the rear. Looks like you may possibly be correct!
http://www.madisound.com/pdf/fostex...s/fe127erev.pdf
Scroll down to see recommended enclosure design. Has anyone compared this to the ref project (simple ported box)?
Peace,
Godzilla |
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| GM |
Greets!
Yeah, from a strictly gross Vb POV, it works out if you use thicker material to make it.
GM |
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| preiter |
I built a pair of the folded-n monopoles. Unfortunately they did not turn out very well. The output starts dropping off below 200 Hz (this is just by ear with a tone generator, I don't have any measurement equipment).
I included a 4 dB BSC circuit (designed using Martin King's spreadsheet).
I did make a mistake building the cabinets. I misread the plans and placed the driver 3/4" too high. Is the geometry of the transmission line sensitive enough that this is likely to be my problem?
How low does the range on this speaker usually extend?
I'm trying to decide whether to rebuild the same cabinet correctly, or try one of the other plans for this driver (maybe the Fonkens). |
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| planet10 |
I'd say there is something wrong somewhere. The ones we built (Chris' mom's) went well below 100 Hz... 50-65 Hz would be my guess. They use boundary reinforcement for BSC.
dave |
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| preiter |
I should clarify.
The output goes well below that. It does reach as low as 50-65 Hz. 200Hz is when the output level is noticably lower than higher frequencies.
Is that normal? I was hoping for something flat to at least 80 Hz. |
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| chrisb |
Try pulling the BSC out of circuit and playing with room placement / mounting height.
The pair I built for mom were raised only a few inches off the floor and tilted back at about 5`. Situated near a back wall this provides some decent boundary reinforcement (1/4 space), as well as pleasant soundstage height presentation.
FWIW, I've played these and a series of FE126 horn designs on a limited number of amp types,(SE and PP EL84 tubes, mini-aleph SS, and of course mom's 80's vintage HK receiver). None were more than 30w, all with great results. While the low damping factor SE tube amps may have added some bloom and weight to the bass over the mini-aleph, I think it'd be fair to say they are not particularly fussy about amp "matching".
As for Dave's comments on dealing with baffle step, at the risk of repeating myself, I've found the easiest way to do that is bi-pole. If your listening room is of sufficient dimensions that the monopole has deficiencies, then you could have enough space for the bipole to come into its own. |
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| preiter |
I believe my < 200 Hz frequency response is beyond what can be accounted for by baffle step considerations. Either the driver just doesn't extend low enough to be usable at those frequencies or I screwed up big time on the enclosure.
It sounds like people are pretty happy with this speaker even without a subwoofer, so I am guessing it is the latter.
So, rebuild the same enclosure? or a different one? Decisions, decisions. |
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| planet10 |
How many hours on the drivers?
dave |
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| preiter |
| Over 100 hours at this point. They are well broken in. |
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| planet10 |
| quote: | Originally posted by preiter
Over 100 hours at this point. They are well broken in. |
100 hours is just starting to get broken in, but certainly enuff that the bass should have loosened up.
dave |
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| stelleg151 |
I've got a pair of 127s on their way here now and planning on building the folded monopole design, so hearing of a audible drop in spl below 200hz is a bit concerning. Dave, forgive me but Im not sure what "boundary reinforcement" means. I think I remember you saying your folded monopoles sounded great without a BSC circuit, so I assume boundary reinforcement is an alternative.
Also Im curious if you (Dave) agree with Chris that the Fonkens will get better sound out of the 127s than the folded monopole design. I prefer the aesthetics over the fonkens and the simplicity of the woodwork, but if the fonkens sound significantly better then maybe I should give them a try?
Thanks for your help guys, looking forward to having some decent speakers. |
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| planet10 |
| quote: | Originally posted by stelleg151
...boundary reinforcement....
Fonkens vrs folded monopole design.... |
Boundary reinforcement is a fancy name for getting them close to a wall which acts as an extended baffle... as these were implemented we actually used the floor & the wall. (the exectution was inspired by the Fostex recommended FE126 TL/BR hybrid)
The Fonkens out perform the ML-TL. They have better control & finesse in the bass. We asked the same question, "is it worth dealing with the extra complexity of the Fonken over the diyA ML-TL" -- so we arranged & did the compare.
dave |
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| stelleg151 |
Ok sounds good, I guess if you think its worth the loss in sound for the simplicity and aesthetics then it will be worth it for me since I dont have much skill with wood.
Thanks again for the help. |
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| planet10 |
The diyRef ML-TL is still a very good speaker....
dave |
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| gus900 |
I've finally got my hands on a pair of Fe127E (7 week wait from Wilmslow audio) and am going to try out the folded monopoles asap. mainly because the WAF is a bit higher than the Fonkens.
I'll post my implementation when it's done / broken in...
Dave, in your experience how close to the back wall is optimal for the ML-TL?
Cheers,
gus |
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| planet10 |
Our implementation, so far, seems fairly unique. When i heard them in Chris' living room they were arraryed across a corner, and out from the wall 2' (60 cm) at the most. Our version is close to the ground, and the angled placement with respect to the walls and corners plays a role. Chris can comment on their siting at his mom's.
There was no lack of bass, but it did have some bloom. If you are using a SS amp some of this bloom should dry-up a bit as the amp takes gretter control of the speaker, but it will also likely get a bit leaner (even our SS amps lean towards lower damping)
dave |
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| gus900 |
Cheers,
I'll be using my Charlize to drive the monoploes, so should be lots of control. Wall placement will be about 1.5' from the back wall and 8-10' away from the corners. I'll most likely put them on small (~6") angled stands. I'll keep you posted...
Gus |
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| stelleg151 |
| quote: | Originally posted by planet10
The diyRef ML-TL is still a very good speaker....
dave |
Yes definately, sorry if I implied otherwise, I wouldnt be building them if I didnt have some faith in your opinion. :)
Anyways, one question I have is how long is the interior wall?
If that unclear, Im referring to the board that the arrow is pointing to.
Just eyeballing it, it looks like it should be around 8", but I wanted to check in case that isnt drawn quite to scale.
Thanks a bundle |
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| planet10 |
| quote: | Originally posted by stelleg151
If that unclear, Im referring to the board that the arrow is pointing to. |
For clarity there should be some more dimensions... i've added them in an updated drawing which i'm now referring to as V1.0.
Some recent experiments show that the design is very tolerant of changes towards larger cross-section.
dave |
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| stelleg151 |
Thanks! Ill be doing the woodwork this weekend, so I should have finished product in a couple of weeks.
Side note: the drivers are tiny! |
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| Godzilla |
| I wonder how much different that speaker would sound if the inner baffle was removed? |
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| Timn8ter |
| My guess would be that more high frequency energy would pile up near the port. |
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| one1speed |
| It appears to be a folded pipe, so I'd guess it would sound quite different. Perhaps a different balance to the sound, possibly a looser bottom end? Interesting query... |
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| preiter |
| Rebuilt my folded-n monopoles as straight monopoles and I am much happier with them. They sound and look nice in my bedroom. |
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| planet10 |
You have a false bottom on those?
dave |
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| preiter |
| Yes, I added an extra 16" onto the bottom to make them floor standing. |
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| stelleg151 |
Finished mine after about 40 hours.
Just wanna thank the guys here for the ideas. They sound great, perhaps a little weakish on the bass, but make up for it in clarity. |
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| rabbitz |
Not quite a fullrange.... more fullrange with help..... but a use for some FR125S drivers I had and partnered with some Peerless 830875 Nomex woofers. Been a fun project and ended up a smooth laid back speaker.
http://www.rzaudio.com/rz52/mongrel.htm |
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| bootzilla |
Hey guys,
Wow, long thread! - After learning about and deciding to buy myself a T-amp to play with and mod (I'm a little late to the party - this is all new to me), I wanted to build myself a decent pair of simple, full range speakers to be able to enjoy music with.
After deciding to use either a Fostex FE207 or FE127, I stumbled across this thread....
Well, 69 pages later - I have ordered a pair of 127's, my T-amp, and some assorted caps - and I am juiced to get started building a pair of the folded monopole design!
Thanks to you guys for starting the thread and developing the designs - I likely wouldn't even be giving this a try if it wasn't for all of your work!
Now I just want the stuff to get here, so I can get started!! |
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| alexg |
I have been lurking this thread and finally I finished reading it.
I have two Sonic Impact t-amp modified with new caps, etc. and I got a tube preamp for this.
I will be building Gio's FE127E sealed bipoles, to be used with my t-amps. As Gio explained, he is using a subwoofer. I will be using a 10" subwoofer set at around 80 to 100Hz.
Hope this will work. |
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| Scottmoose |
I'll have you know that if there's any lurking to be done, I'm the only one who'll be doing it... :D
Sounds a plan. My only slight concern is that with the sub crossever over that high, you could well end up hearing the LF from one location and everything else from another. Sound localisation only really drops off below ~75Hz. |
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| alexg |
| quote: | Originally posted by Scottmoose
Sound localisation only really drops off below ~75Hz. |
Thanks for the info, I thoght all along that localization drops off at 100Hz.
No wonder, some bass on my home theater setup (crossed at 100Hz, which I currently used for audio) tends to be on the right side where my subwoofer is.
:xeye: |
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| rabbitz |
| quote: | Originally posted by alexg
I will be using a 10" subwoofer set at around 80 to 100Hz.
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Depends a lot on the crossover in the sub and if it's 2nd order like most sub amps there's still quite a bit of information that sneaks through but less of a problem with 4th order crossovers on subs.
Try the sub with stereo music (not HT LFE channel) and listen if voices come through. You'll usually get a bit but if it's too noticable, then drop the sub crossover point. |
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| GG |
Hi alexq,
Be sure to keep us posted on your progress!
A sealed enclosure rolls off naturally at 12 dB/octave (2nd order).
With WinISD, a second order sub @ 85Hz should be optimal and is a good place to start. The Martin King models say 75Hz. Of course at these low frequencies it will be room dependant so you will have to experiment with the cross over point.
For me, 80Hz 2nd order has been working very well. Very rarely do I notice localization.
Now that you guys mention localization, you have got me thinking.
If you run the speakers in parallel for a 4 ohm load and then add a 4 ohm resistor in series for an 8ohm load, this should bump up the Q of the drivers and get you more bass at the cost of some efficiency. Then you should be able to drop the crossover point a little more. I will have to try this out. |
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| stelleg151 |
Im feeling like my folded monopoles arent really putting out as much in the lower midrange as I had hoped. It just seems that in comparison to many speakers near the same size they just arent filling the room nearly as well.
Granted they only have about 50 hours on them, and they already sound better than they did at first, but I am not optimistic that they will eventually fill the room a lot better.
One thing that was suprising to me was how much stuffing I was putting in. I put in the recommended 1/2 a pound for each cabinet, and it was packed in there pretty tight by the time I was done. Could it be that its so tight that it is muffling the lower mids?
Im being overly nitpicky here, I really do like the sound, and will eventually combine them with a sub, but I feel like the 200-600hz range is just a tad weak.
Thanks,
George |
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| chrisb |
A few ideas:
If you're listening to them mounted on the floor as shown, try tilting them up between 5-8 degrees, or mounting on simple stand 12-14" off floor.
Hate to ask the obvious, but have you checked phasing on internal connections and speaker wiring? As recently as last weekend I made the same mistake when moving things from one end of a room to the other.
Assuming you can get at all the stuffing locations in the box, try pulling at least half out, and then play up & down from there.
I'm a firm believer that after all the math is said & done, it's still up to your ears to tell you what sounds right.
I'm familiar enough with the performance of this design to know that filling even a moderate sized open space room shouldn't be a problem, except for the bottom octave or so.
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| stelleg151 |
Heh Im pretty sure I got the phase right, but Ill just switch em to make sure.
I worry a little about unscrewing the driver again, as I have already unscrewed it and rescrewed it once, to put the grills on.
As for tilting them up, I now have them in a different setup in my bedroom on a desk, about 8 inches from the wall.and its not that they dont fill the room, its just they fill it with their beautiful mids and highs and not so much else. ;)
Thanks chris, youve been a huge help,
George |
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| planet10 |
I think i mentioned it before, but it is worth rpeating. A significant improvement in the FE127 (&126) can be had by modifying them (if i do say so myself).
It is quite hard to get a good pic...
These mods are a direct result of comments Mark MacKenzie made earlier on in this thread crossed with my 30 years of experience modding drivers. More info on my planet10-hifi site (including a link to the FR Forum where i posted early results). I will be getting up a more detailed how-to on my website, but that is just one of many tasks in my queue.
dave |
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