Bipolar miniOnken and source of Canadian supplies

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I've searched the Bipolar miniOnken and come up with very little info, in fact it is only referenced in a couple of threads. I'm interested in opinions about its sound.

I have a pair of NOS Radio Shack Dipoles that I hope to use with them x-over'd at somewhere from 10 to 13K.

I also would like to know where you Canadian guys are buying supplies like caps, silver wire and stuff like that. Solens only seems to list their own house brand of caps and I didn't see silver wire listed at all.

Any suggestions of any type are welcome.
 
Well I saw the plans and one of the things that appeals to me is that the cavity at the bottom, the sand cavity, is plenty big enough for some small subs to work in. My intention is to build them with out the sub and see what I think.

So has no one built a set yet?

How about Canadian suppliers for x-over parts and silver wire?
 
binarywhisper said:
Well I saw the plans and one of the things that appeals to me is that the cavity at the bottom, the sand cavity, is plenty big enough for some small subs to work in. My intention is to build them with out the sub and see what I think.

So has no one built a set yet?

How about Canadian suppliers for x-over parts and silver wire?

I have built single driver Mini Onkens based on the Planet_10 design, with a bit more volume and vent area. I have seen and heard only one pair of bipole Fonkens, they sounded nice but I prefer the single driver version.

Caps and wire here:

http://www.partsconnexion.com/

http://www.takefiveaudio.com/

Jeff
 
thanks for the links, thats exactly what I needed.

I already have some 125FR's and like them quite a bit. I've had them in many configurations but currently have them in a small heavily damped ported box running full range with a dipole tweeter sitting on top and a 12" woofer in a sealed enclosure with a coil x-over @ 300hz out of phase.

I find the tweeter and woofer really fill out the sound significantly. Adds the sparkle and the grunt and prehaps as importantly I get enough spl out of them to make it more then a near field solution.

They are currently very listenable but I would like more spl and I still find the sound stage a little small and distant. The speakers do not completely disappear as they should.


With the extra 3db I'll get from the bipolar design I can remove the l-pad I have on the dipole tweeter simplifying the design in the process.

What is the sound stage like with the minionken? Do the speakers disappear?
 
binarywhisper said:

What is the sound stage like with the minionken? Do the speakers disappear?

Soundstage with the Fonkens is very good, depending on source and program material. This is with modified Fostex Fe127's of course, and after a decent break-in period. It's been quite a while since I listened to the FR125 based Onkens, but I'd expect the soundstage to be pretty close (monopole versions).

They come pretty close to disappearing, considering that you are listening to a single driver in a box. The trick is to keep that quality when adding more speakers to cover bass and treble.

I think you're concept of having bipole FR125's, powered subs in the bottom, and a tweeter on top is a good one. It's just a matter of fine tuning with XO points etc.

Jeff
 
vinylkid58 said:


Soundstage with the Fonkens is very good, depending on source and program material. This is with modified Fostex Fe127's of course, and after a decent break-in period. It's been quite a while since I listened to the FR125 based Onkens, but I'd expect the soundstage to be pretty close (monopole versions).

They come pretty close to disappearing, considering that you are listening to a single driver in a box. The trick is to keep that quality when adding more speakers to cover bass and treble.

I think you're concept of having bipole FR125's, powered subs in the bottom, and a tweeter on top is a good one. It's just a matter of fine tuning with XO points etc.

Jeff

allow me a couple of comments:

Adding an additional rear firing (or in your case dipole) tweeter can certainly aid in the illusion of ambience, but be careful considering a full range bipole or open baffle for that matter, unless you've got at least 3 or 4 feet of clear space available behind the speaker location, and several to the sides as well. They'll certainly fail to elicit their potential "magic", and you could be disappointed for the wrong reasons.

The mono pole mini-onken / Fonken design accomplishes a reasonably good compromise between the box "disappearing" and clean although subterranean bass response. Midrange imaging and soundstage width is quite remarkable.

If you haven't already investigated cone treatments for the FR125's, you might want to contact Dave about some experiments he's made.

Even after at least 6 pairs, the Fonken is not the quickest build in the world. If you'd like to try a much easier proof of concept, the more conventional flat panel design that Dave refers to as the "GR Fonken" comes pretty darn close to the performance of the original. Unless you're determined to execute gallery quality woodworking, they should take less than a day to put together.

As to addition of woofer(s)/sub(s), that's very much a personal choice - I've yet to find an easy to implement and entirely seamless design that doesn't dramatically change flavor through the pass band. In addition, my main listening room is tiny enough (approx 240 sq ft), that it's more trouble than it's worth. By the time you add enough bass traps to deal with standing waves and compression, etc, the room is too small for more than one listener, and what's the point if you can't show it off? :whazzat:


However, I know that Dave has some designs for incorporating actively powered woofers into a pedestal base for the main speakers that would reduce some of the clutter. Since the monopole design is essentially a large bookshelf sized box, and requires a stand of some sort, why integrate the woofers? I'll have to try a pair of those myself some time.
 
chrisb said:


The mono pole mini-onken / Fonken design accomplishes a reasonably good compromise between the box "disappearing" and clean although subterranean bass response.



oops, I didn't catch the above type in time to edit the post - obviously that should say "although NOT subterranean bass response"

No doubt an appropriately sized "onken" style woofer / sub enclosure could be designed to achieve that, but it wouldn't be both small and efficient.
 
chrisb said:
No doubt an appropriately sized "onken" style woofer / sub enclosure could be designed to achieve that, but it wouldn't be both small and efficient.

How about 111 liters, 92dB efficient and tuned to 38Hz. Some might say that this is an appropriately sized Onken.;)

Jeff
 

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chrisb said:
full range bipole or open baffle for that matter, unless you've got at least 3 or 4 feet of clear space available behind the speaker location, and several to the sides as well.

my living room is pretty average size 17' x 17' (289 sq ft) and I've never minded pulling the speakers out into the room when I do more serious listening.

There are functionally no corners in the room and the wall opposite is floor to ceiling bookshelves that are surprisenly good at eating deflections. I'll be spraying the acoustic ceiling sometime this month. All in all its a very well damped room with very few problem spots and with a little tweaking it will get better.

on a side note, I live in a small, 1200 sq ft, house and the wall to ceiling bookshelves I built in the living room back onto floor to ceiling closets running the full length of the main hall way. Bottom line is that wall is now 42" deep. I can play music at very high levels and my light sleeper wife is out like a light 20 ft away. Very cool

Midrange imaging and soundstage width is quite remarkable.

well that is probably my primary concern.

If you haven't already investigated cone treatments for the FR125's, you might want to contact Dave about some experiments he's made.

I was not aware there were any treatments for the 125's. Thats interesting. Dave??? U there :)

However, I know that Dave has some designs for incorporating actively powered woofers into a pedestal base for the main speakers that would reduce some of the clutter. Since the monopole design is essentially a large bookshelf sized box, and requires a stand of some sort, why integrate the woofers? I'll have to try a pair of those myself some time. [/B]

Well that was more or less my original idea but I would really like the extra 3db I'd pull from a 2nd 125 as well as BStep elimination, removal of the Lpad on the tweeter and the push push config offers several benefits as well.

I guess this design claims to remove the BStep requirement due to the heavily chamfered front baffle though eh? mmmm .... what if I placed both 125's on the front baffle :)
 
vinylkid58 said:
They come pretty close to disappearing, considering that you are listening to a single driver in a box. The trick is to keep that quality when adding more speakers to cover bass and treble.

thanks for the reply.

I think you're concept of having bipole FR125's, powered subs in the bottom, and a tweeter on top is a good one. It's just a matter of fine tuning with XO points etc.

Jeff

yeah I think so as well. It's not a real 3 way, there is no x-over on the 125fr's. I'm thinking of buying an electronic x-over just to give me the ability to play with different settings. Seems like good way to fine tune setting prior to building the final x-overs.

I was thinking of just grabbing a electronic car x-over from ebay and using that . I have a number of beefy fully regulated 12v power supplies laying around. ... what do you think?
 
binarywhisper said:
I'm thinking of buying an electronic x-over just to give me the ability to play with different settings. Seems like good way to fine tune setting prior to building the final x-overs.

I was thinking of just grabbing a electronic car x-over from ebay and using that . I have a number of beefy fully regulated 12v power supplies laying around. ... what do you think?

An electronic sub x-over would really be the best way to go. I looked at some of the pro style 2-way + sub crossovers a while back, but didn't save the links. The car stuff could work, just as long as it has a decent range of settings.

Jeff
 
binarywhisper said:


my living room is pretty average size 17' x 17' (289 sq ft) and I've never minded pulling the speakers out into the room when I do more serious listening.


There are functionally no corners in the room and the wall opposite is floor to ceiling bookshelves that are surprisenly good at eating deflections. I'll be spraying the acoustic ceiling sometime this month. All in all its a very well damped room with very few problem spots and with a little tweaking it will get better.



My smaller room is L-shaped less than 9ft wide at the narrow end and approx 20 ft long, and being a finished basement, the ceiling is less than 8ft. All things considered a small room with lots of corners, and very easy to overload with bass - for example the Ron Clarke A126 horn will, but the Frugelhorn or monopole Fonken with FE127 won't.

The larger room that my wife sometimes let me play with is a relatively generous 15'6" x 26". It was only recently renovated to her specs as family / TV room, is only lightly treated with some upholstered furniture and rug over about 1/3 of the lino'd floor. Well, I did get a new 42" plasma & HD receiver out of the bargain, so I shouldn't complain.

But ask Dave which room he'd prefer to listen in?




on a side note, I live in a small, 1200 sq ft, house and the wall to ceiling bookshelves I built in the living room back onto floor to ceiling closets running the full length of the main hall way. Bottom line is that wall is now 42" deep. I can play music at very high levels and my light sleeper wife is out like a light 20 ft away. Very cool

lucky man




I was not aware there were any treatments for the 125's. Thats interesting. Dave??? U there :)



I know what's involved, but should let Dave field that question. I can say that it was one of those "gotchas" . had no advance warning, and he was playing them quietly in the background during a conversation when I clued in something was much more transparent and up-front in the midrange presentation.





Well that was more or less my original idea but I would really like the extra 3db I'd pull from a 2nd 125 as well as BStep elimination, removal of the Lpad on the tweeter and the push push config offers several benefits as well.

I guess this design claims to remove the BStep requirement due to the heavily chamfered front baffle though eh? mmmm .... what if I placed both 125's on the front baffle :)

The beveled front baffle of the mini/ F onken design serves several purposes, including aesthetics, but I don't recall anyone suggesting it will eliminate BS loss on the monopoles. A much wider baffle and shallow cabinet such as on the ML Voigt design "Mileva", will have lower frequency and quantity of BS loss, particularly when situated close to the back wall as in my A/V system, but pays a premium in other areas.

Bipole drivers will certainly amass the benefits you describe above- I've just be occupied with other projects, and not got around to trying that yet with the Fonkens. Placing both 125's on the front baffle will not yield you all the same benefits, and will complicate your crossover design.



Jeff:

We'll get around to it someday, but in the interim, I don't think I'd classify 111 liters (3.9 ft^3) as "small" - I've had more than a few powered subs in the A/V and audio system, including an Adire Shiva 3ft^3 vented. None have yet succeeded in disappearing physically and blending seamlessly with the mains. The best quality bass I've had the opportunity to hear in either at home was open baffles, but that's hardly practical.
 
chrisb said:
We'll get around to it someday, but in the interim, I don't think I'd classify 111 liters (3.9 ft^3) as "small" - I've had more than a few powered subs in the A/V and audio system, including an Adire Shiva 3ft^3 vented. None have yet succeeded in disappearing physically and blending seamlessly with the mains. The best quality bass I've had the opportunity to hear in either at home was open baffles, but that's hardly practical.

Sorry Chris, I guess I should have explained what the pic was supposed to be. It was an old mini-onken design exercise using the Hemp Acoustics FR8, hence the large cab for 38Hz tuning. Maybe I'll go back thru the numbers to see what the fr plot is like.

Jeff
 
vinylkid58 said:


Sorry Chris, I guess I should have explained what the pic was supposed to be. It was an old mini-onken design exercise using the Hemp Acoustics FR8, hence the large cab for 38Hz tuning. Maybe I'll go back thru the numbers to see what the fr plot is like.

Jeff

no worries, but not so "mini" now is it? :) :)

If you're considering a pair of woofers for bass augmentation and high-passing the mains, I'd suspect that tuning for even mid to high 40's would be more than adequate. If sized carefully, they'd make great matching speaker stands.

But it's probably obvious that I'm not a great fan of subs - of those I've heard to date, I could easily live without all. I'm not a big fan of Guinness, either - no accounting for lack of taste I guess. :clown:
 
I've decided I'm going to go ahead and build the bipolar miniO.

I'm going to be using 2 single 125fr's for each rear channel and (to begin with) one for the center channel.

I'd really prefer not to introduce components to correct the impedance but I guess I'll have to as the 125fr's only come in 8 ohm versions. I''ll put two sets of binding posts per miniO so I can play around.

Posted in response to chrisb
Not sure where I got the beveled edge BSC idea from but now that I'm fully awake ... well ... it was literally a 1/2 baked idea or prehaps I should say a fully baked one :)

Dave did I read somewhere that you have had good experiences with 2 single strands of teflon coated plenum grade wire from a cat5 cable per channel for speaker wires?

I'm currently using 3 full cat5 cables woven together. The single strand seems odd to me but I was going to try it. The packing tape used to separate the wires apparently needs some superhuman ability to apply that I don't possess. I found myself sitting there is a knot of wire and tape which I balled up and threw at the cat because it appeared to be amused. :)
 
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binarywhisper said:
I'd really prefer not to introduce components to correct the impedance but I guess I'll have to as the 125fr's only come in 8 ohm versions. I''ll put two sets of binding posts per miniO so I can play around.

Are you taking about a zobel or trying to make everything 4 or 8 ohms? If the latter that adjustment for level should be built into the HT processor.

did I read somewhere that you have had good experiences with 2 single strands of teflon coated plenum grade wire from a cat5 cable per channel for speaker wires?

I'm currently using 3 full cat5 cables woven together. The single strand seems odd to me but I was going to try it. The packing tape used to separate the wires apparently needs some superhuman ability to apply that I don't possess. I found myself sitting there is a knot of wire and tape which I balled up and threw at the cat because it appeared to be amused.

Single strand vrs multi is likely amp/speaker dependent...

The secret to the packing tape is to tape the appropriate length of packing tape sticky side up on the floor. Lay the wires on top, then add another layer of packing tape (sticky side down, and then trim the hold-down tape off

dave
 
planet10 said:


Are you taking about a zobel or trying to make everything 4 or 8 ohms? If the latter that adjustment for level should be built into the HT processor.



Single strand vrs multi is likely amp/speaker dependent...

The secret to the packing tape is to tape the appropriate length of packing tape sticky side up on the floor. Lay the wires on top, then add another layer of packing tape (sticky side down, and then trim the hold-down tape off

dave


but the real secret is the random deposition of feline follicles as damping material in the adhesive matrix of the packing tape - and it sounds like you'd have easy access to that also


As much as Ruth tries, it gets everywhere.
 
planet10 said:
Are you taking about a zobel or trying to make everything 4 or 8 ohms? If the latter that adjustment for level should be built into the HT processor.

yeah 4 or 8 ohm. Its not levels that concern me but overall combined impedance as presented to the amp. Using a Panny and they do not handle (apparently) reactive loads well and a combined impedance of less then 2 ohms will, apparently, causes them to puke.

I have no experience to base this on, just reading.


Single strand vrs multi is likely amp/speaker dependent...

The secret to the packing tape is to tape the appropriate length of packing tape sticky side up on the floor. Lay the wires on top, then add another layer of packing tape (sticky side down, and then trim the hold-down tape off

dave [/B]

yeah, thats pretty much true of everything to some degree. I'll give ur method a shot. Thanks Dave.
 
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