[jimluu]

I've been wanting to build an OB speakers for a while.  I own several 'box' speakers, and I just want a different sound.  I've heard a couple of pairs of OB speakers in the past, and I like the sound.  But that's the extent of my OB experience.

I have recently purchased 4 15" subs to handle the low end.  I plan to mount them in dipole fashion, similar to the JAMO r909.  Now I must find the perfect speaker for the rest of the audio spectrum.

I've decided that I'll spend any amount of $, as long as I get the 'best' driver(s).  I like the ideal of a full range driver, or a point-source type driver, but am open to any suggestions.  I mostly listen to jazz, vocals, and some instrumentals.  I truly appreciate ANY suggestion.

I'm intrigued by the audio nirvana 12", and the PA 15cx38.

http://www.nirvanaspeakers.com/nirvana.html
http://www.commonsenseaudio.com/paudio.html

http://www.diycable.com/main/product_info.php?products_id=652&Cid=8b446dc65df9e9d1f785b4e01b2c5ec4

[Vapor Audio]

I'd add a C-Quenze 15H and Mundorf AMT for the mid and tweet ...

[JoshK]

I'd use the Fertin 20EX for the mid and not sure for the tweeter.  I recently heard the Fertin at a local get together and it was spectacular.  If one was to take the low's away from the driver then the result could be breathtaking. 

[jimluu]

Thanks for the quick replies.  I like the freq. graph of the C-Quenze 18 H.  Real smooth  through the midrange.  The AMT looks great as well.  Can't find much info on the Fertin 20EX.  Would you guys mind pointing me to a US based distributer?

Any one used audio nirvana?

[JLM]

Here's my choice for a very high quality 2-way O.B.:

http://www.enjoythemusic.com/magazine/equipment/0107/diy_loudspeaker_project.htm

I'd avoid David Dicks (commonsense/audionirvana).  He changes names, brands, and speaker designs every couple of years.  Got one of the worst reviews ever with a former design and had the absolute worst reply to it ever.  Offers no returns, hides the use of tone controls, and won't demo his stuff outside his own room.

[gitarretyp]

It's not quite "no expense spared," but the isiris project on HT Guide is using some pretty high end drivers. Accuton C173N-T6-90 mids, Aurasound NRT 18-8 or Ciare ND 18.00 W1 woofers, and a BMS4540/ENG-1 tweeter/waveguide. It's still a work in progress, but should be quite nice when finished.

[jimluu]

I've read many posts regarding larger full-range/coaxial drivers, and just about everyone have positive things to say.  The appeal of a simple cross-over or no crossover is great to me, since I don't know too much technical aspects to crossover design.  I've been following the development of the Arvo part and Isiris, but am some what put off by the complexity of the crossovers.  There is something to be said for simplicity.  One of the reasons that I decided against the Orions is the extreme multitude of electronic manipulation involved.  I guess I'm searching for the something that works great, without much intervention.

David at common sense audio seem convinced that the PA15cx38 is the best speaker he's ever heard, and that his own audio nirvana 12" are a close second.  I've yet to run across any discussion of these speakers on an open baffle.  Is he just blowing smoke, or are they that good?

[Dmason]

I would take a serious look at either Radian or BMS compression drivers, BMS makes coaxial C/D's, using a purpose-designed DDS waveguide/horn, with your woofers.

The $$$ Zone with open baffle is 1500Hz and below.

Some of the new pro audio mid/treble drivers are just amazing.

If you want a balls-out OB system, look hard at the www.rane.com RPM series of active contouring devices. Apart from being fun and educational, they will make ALOT of sense, once you own one and use one, as I have for a few years now.

Low damping factor on diaphragm transducers, a la single ended triode flea amps, and high damping on the big cones, a la pro audio or T amps and you can REALLY dial in some spectacular sound.

Altec, believe it or not, had dipole PA systems in the early 70's. They employed exactly this basic technique.

[AdamM]

Add these to the list for review:
http://www.phy-hp.com/English/Products/Drive_Units.html

Not cheap, but some stunning speakers use them and they get glowing reports

http://www.phy-hp.com/English/Products/KM30_SAG_E.html

Very boutique

/A

[EProvenzano]

I would take a serious look at either Radian or BMS compression drivers, BMS makes coaxial C/D's, using a purpose-designed DDS waveguide/horn, with your woofers.

The $$$ Zone with open baffle is 1500Hz and below.

Some of the new pro audio mid/treble drivers are just amazing.

If you want a balls-out OB system, look hard at the www.rane.com RPM series of active contouring devices. Apart from being fun and educational, they will make ALOT of sense, once you own one and use one, as I have for a few years now.

Low damping factor on diaphragm transducers, a la single ended triode flea amps, and high damping on the big cones, a la pro audio or T amps and you can REALLY dial in some spectacular sound.

Altec, believe it or not, had dipole PA systems in the early 70's. They employed exactly this basic technique.

What do you look for in a pro-audio coaxial in order to qualify it for open baffle?
Here is one I found that looks interesting but i have no idea how it would perform in an open baffle:
http://www.voltloudspeakers.co.uk/About_Us/about_us.html

[EProvenzano]

The darn web site won't let me link to the appropriate driver.
Here's the model number: RVCXD3153

[joninww]

2 years ago, I was looking at Fertin and Supravox as the main driver for my OB's.  Fertin did not have a US distributor, but Supravox does.  I ended up buying Supravox 215 Sig bicones from supravox.com for about $720 including shipping.  Also looked at PHY-HP, very highly rated.  If money were no object, I would have bought the Supravox field coil drivers (about $2900/pair).  Some believe these are the best full range drivers for open baffles available, and the best sounding speakers period.

[RAW]

You mean like these
Can not tell but you all will see tyhem in a short time.
No not my pruduct for those who will ask.

Did 2 designs for them with our ribbon.

[jimluu]

You mean like these
Can not tell but you all will see tyhem in a short time.
No not my pruduct for those who will ask.

Did 2 designs for them with our ribbon.

Is that an all supravox set up with a ribbon supertweeter   Maybe I'm not quite ready for that price range yet, but realistically $1500 or less.  Never heard supravox.  Hopefully someone will have them at the rmaf.

[D OB G]

Hi jimluu,

Regards the AudioNirvana, I've used the 8" with phase plug on an open-baffle above about 200 Hz.

They have a rising treble, so they need to be listened to off axis, but they beam terribly, which means the limited extension is reduced further still. They are very peaky.

They CANNOT handle anything complex.  This is the big negative for me.  Solo voice- maybe.  Anything else- distortion.

All the above I have found to be my experience with the Fostex FE206e, which has a good reputation in some quarters, except that I find it to be worse !

Both of these speakers were extensively run-in, excruciatingly!

That is my experience with full-range drivers (except for a cheap Phillipines Coral clone- which wasn't too bad!).  I think you will understand my reluctance to try B200, Supravox e.t.c.

I wonder about the appeal of a simple or crossoverless design with full-rangers.
By the way, twin cone drivers are not crossoverless.  They just use mechanical properties rather than electrical. There seem to be hundreds of posts about how to tame this peak or that, LR and LCR circuits e.t.c., e.t.c.

And yet... there are obviously many successful full-rangers out there.  The Visaton B200, which I have not heard, seems to be in the most consistent regard. Maybe we are looking for different criteria.
Some people dislike dome tweeters, yet they can have excellent off-axis response, which cannot be achieved with larger drivers, which are producing treble not with pistonic movement, but rather by the nature of the cone breakup.

I belive off-axis response, that is trying to achieve equal energy through as much of the frequency range as possible, is a desirable aim with open-baffle speakers..

Many contributors concur with Linkwitz that the rear radiation doesn't need to exceed something like 1500 Hz, so a tweeter doesn't need to be open baffle.
I've tried using a second tweeter in dipole configuration, padded and unpadded, and I've always found the sound to be worse.

Conversely, a full-ranger might seem to be producing open backed treble, but because of the magnet, spider and chassis obstruction, the rear output is very uneven, and not very extended. 

So you can see I'm a three-way speaker man, therefore the question for me is, what is the best combination of tweeter, midrange, and crossover, keeping all drivers within their pistonic range as much as possible, as well as being acoustically close.

David

[Grumpy_Git]

Many contributors concur with Linkwitz that the rear radiation doesn't need to exceed something like 1500 Hz, so a tweeter doesn't need to be open baffle.
I've tried using a second tweeter in dipole configuration, padded and unpadded, and I've always found the sound to be worse.

Hasn't Linkwitz just updated the Orion to add a second rear-firing tweeter?

Nick.

[JLM]

The $383 (madisound) Fostex F200A is rated raw at 30 - 20,000 Hz.  This is not your typical Fostex extended range driver.  Big Alnico magnet, 89 dB/w/m, 8 ohms, aluminum dust cap, no whizzer.  It sounds rich and full, not thin like so many extended range drivers, most like the B200 are better termed as big mid/tweeters.  Note that I don't use the term "full range" as nearly all lack deep bass (IMO the foundation of music).  I do term the F200A as full range (for the purposes of musical reproduction).

The F200A has been successfully used in ported, open baffle, and transmission line (like my Bob Brines FTA-2000) designs.  The transmission line (TL) extends bass, cleans up the midrange by absorbing the back wave, resulting in a bit more open (like OB) sound.  The recent work of Martin King and others have finally allowed for mathematical modeling of TL.  They are not hard to build as so many claim, just a carefully located, solid internal brace or two to create the line.  My first speaker cabinet was a TL.

Of course an 8 inch driver without help (whizzer/tweeter) will beam, but most serious listeners have a favorite chair, so just aim them there (or just behind for the best imaging).

Single drivers, especially nearfield, have a coherency that multiple driver speakers cannot (a dome tweeter can't sound like a cone at the crossover frequency).  They image vertically, a line array cannot IMO.  And they're "active" (one channel of amplification per driver) which has huge, undeniable  advantages.  Are they perfect?  No.  There is no perfect speaker.  You prioritize and build to a budget.

[jimluu]

Thanks for all the great info.  The Fostex sounds real interesting.  I think I saw one at the RMAF last year, but in a horn configuration.  I'll have to listen to it more closely at this year's event.  I've heard good and bad about the b200 as well.  They are not too expensive, I may just try a pair....could always ebay it off.  I heard Hawthorne audio is coming out with a Sterling silver iris, which could be interesting.  I kinda like the sound of the bigger drivers, but in the past I have not liked the rather mechanical sound of compression drivers that is in all these proaudio coaxials.  I wish there is some way of trying them out before buying them since they are so expensive.  The 18sound coax are almost $650 a piece!  Anyways my diycable subs are due to arrive today....can't wait

[JoshK]

I wholly agree with David and also agree with Dmason.  When I heard the Fertin's OB recently I played some progressive metal on them when the host was gone.    That was a no-go.  The host pre-warned us that they wouldn't work with complex music and he was right, but for jazz, vocal, solo, chamber they are amazing.   The room was also too big to play loudly with any real dynamic impact. 

However, my thoughts were to use them as a wide range midrange and not a full range.  I am in the camp that full range still needs support on the ends in order to achieve higher performance.  The host also had a quad of 15" woofers in OB for supporting the bottom but I didn't hear with the Fertin's high passed, only with the woofers supporting, though his setup made it possible I left too early to hear that iteration. 

I think if you are apartment dwelling or have a small room or your tastes are for above mentioned music the Fertins OB I could easily recommend (or looking into similar style driver), for me it isn't that simple and Dmason's recipe is one I am looking to follow with is inspired/parralleled by the Isiris concept project.

[nullspace]

I have a pair of Fertin 20EX on the JELabs OB, and they definitely will not 'rock out' with you and your entire neighborhood. I would think biamping, with a 200hz PLLXO for the amp driving the Fertins + a supertweeter (I use a Fostex FT96H) and a big SS amp driving a bunch of 15"s would be awfully nice.

If you search for Fertin in this forum, the fullrange forum over at diyAudio, and High-Eff at AudioAsylum you'll find many comments on the Fertins by myself and others (nl - Nate Lewis at AA has been doing a bit as of late as far as highpassing his Fertins).

If you are set on coaxs, I would recommend the Radian 15" + a bunch of Hawthorne 15" Augies for bass support.

Regards,
John