[richidoo]

Would you have some recommendations in mind? I've the circle for your posts on OB. It seems GR Research offers 12" subs for OB as well as servo amps. Are other combos that'd meet my need?

Rythmik/GR is the one I was thinking of.

Hey Rich,
A question regarding high Qts vs low Qts on open baffle drivers, mainly bass drivers.
I've been using the Alpha 15 which has a relatively high Qts  of 1.26. In the  process of upgrading my open baffle design with a little more effective bass driver, the Alpha 15. I've had some recommendations like the Delta 15lfa or even the Definimax which have a Qts in the mid 50s. If I use one of the lower Qts drivers and not use EQ, could I get by with bass boost on my plate amp?

Yes, it should work if your adjustments are flexible enough. The bass boost on your plate amp is an EQ adjustment. It's definitely worth a try to see if your amp can make it sound right. With that Qts .5, large cones and such large baffles you may need only a small boost. When you go to the plate amp it will be easier to adjust the crossover slopes and driver levels.

The Alpha 15 is ok in my current application (18 in baffle with 12 in wings on the back). The bass is sometimes a little thin and not focused. Right now I am not using a separate amp on the bass. The main amp is driving the mids and bass (with a cap and inductor filter).

The lack of focus is due to the extremely high Q of the Alphas. But there should be plenty of volume with your setup (highQ, large cone, big baffle) so the thin bass is probably caused by your crossover design - the Alphas are not playing loudly enough to match your mids. This is tempting to do especially when Alpha has only 1st order LP filter, to drown out the Alpha's midrange smearing. But then when the midrange driver rolls off in the bass then below that there's not enough volume from Alphas alone. You can attenuate the mids/tweeters to match the Alphas, or you can increase the size of the coils on the Alphas so there is some passive bass boost on them so they play louder down low, and attenuate with rising frequency until they are matched level with the mid drivers at the crossover freq.

[Quiet Earth]

Seems like we had a similar question not too long ago.... http://www.audiocircle.com/index.php?topic=68901.0

To be honest with you, I still can't wrap my head around why we need a special type of speaker to play classical music. It seems like a "good speaker" would be a good speaker for all music. Music encompasses a lot of possibilities. I can think of a lot.

Not to mention, the speaker is only one part of the system, the last part. (Unless you count the room of course.)

[JohnR]

You don't need a special type of speaker to play classical music, but to answer the OP, yes they are.  But sadly there is a depressing tendency for people to make OB speakers and ignore every possible speaker design principle that's possible to do so. (Sorry about the grammar.) IN that case, it's hit or miss.

[ajmac]

Thanks Richidoo for the clarification; but other than Rythmik/GR, is there any other combo that you'd recommend?

Hi Quiet Earth, I saw your system of AN speakers & amps. They are certainly nice for most (if not all) sorts of music. An older audiophile close to my location have the same speakers, and I sometimes get to go over there to enjoy with him. The AN-E certainly have a excellent presentation on classical pieces, but even the speaker kit is over my budget.

Hi JohnR, do you mean 'some' (well designed & implemented) OB are good for classical music? Would you mind pointing me to them (I presume they are DIY)?

Over last weekend, I visited a commercial DIYer, that sounds like oxymoron. Anyway, the guy built speakers (all sorts) and sell them. He has advertising for a pair of hybird open baffle speaker that look like the X-stitik from GR (please note: just look alike). However, the room was too small to do justice to the speakers, and the tube gears suffer from the bass notes and add some strange noise to the system. I have to say I wasn't impressed.

There is also a local dealer for NOLA. I'd probably make a trip over in the following weeks. Just to see how well/or not do they play full symphonies.

[richidoo]

They're the only brand I know making servo drivers designed for OB.

OB is fine for classical music. It has a different sound in the room because of its LF radiation pattern, and because of the rear wave reflections. You have to try it to know if you like it. I personally don't like it. The rear wave and the dipole radiation don't work for me. ymmv

Linkwitz Orion is a DIY OB design worthy of investigating if you are bent on DIY. I recommend you use a commercial digital crossover like Xilica or dspMusik instead of the kit's analog crossover. The drivers in the Orion are excellent and they can handle loud classical music without distorting. You might even find a used pair.

I don't know of any other DIY OB designs that are suitable for the seasoned and jaded symphonic music audiophile. Doesn't mean there aren't any others.

[ttan98]

Ajmac,

I have built a few OB speakers over the last 5 years and the sound quality varies depending on your system/room/your taste, my last project was a LXMini clone based on my own design. I believe this system in a small to medium size room it is hard to beat. It also offers you many other advantages in your situation are:

1. Cheap and fast to build
2. you can then find then tune it with your system and room
3. Sounds great beats any 2 way box speakers I own hands down.

Using this system as a benchmark you can then either graduate to build a more complex OB system available out there OR buy a commercial system, by now you know what you like and what you don't like about an OB system and with these criteria you can pick the best money you can afford system. During the process of building, testing and listening you learn heaps.

Cheers happy OB hunting.

[rabbit]

rabbit - Appreciate your sharing your own experiences.  Sorry to hear that the Silver Iris did not do it for you.  I know of several folks who love them, so as with many things it often comes down to listening preferences.

actually it has nothing to do with preferences. the silver iris are one of the worst speaker designs i have ever put my hands on at home. they dont work at all the CD dont integrate with the woofer regardless of crossover and the passive crossover makes it even worse. digging into resonance frequencies, full range load on a poorly specd woofer that breaks up before 1k. no waveguide and a uncontrollable polarresponse etc.
i dont understand how anyone can enjoy these speakers, a cheap econowave leaves them in the dust!
sorry but on most forums outside hawthorne this speaker is generaly laughed at.

[mcgsxr]

Rabbit - it's good to be passionate about audio.  I have been for years, and as long as I keep learning, it's fun.  There's lots of paths to genuine audio happiniess.  I have tried a wide number over the years.  In fairness to guys who pour their hearts into small audio businesses, let's keep a focus on what you have preferred in your own journey.  I am not a fan of threads that deteriorate about best or worst. 

A healthy audio scene keeps us all passionate about what we hear. 

My current path includes a set of Maggie's.  I find them satisfying for many genres in my collection.  I recall excellence from the OB Visaton b200, those added a coherence hard to replace.  I played violin in my youth and listen to some light classical.  I tried DIY OB all those years ago because it seemed interesting and fun. I learned a ton.  I have since run boxed speakers but have returned to the OB approach.  I find the musical presentation of OB to be the most enjoyable for me. 

[ajmac]

Hi All,

Just an update on my search: I went to a local dealer to listen to the maggies. I spent about 30 minutes on the 0.7 and 90 minutes on the 1.7i. For sure, the 1.7i have a fuller presentation of an orchestra. Both speakers are driven by a Naim SuperNait2 (80w/ch). The amp and the 1.7i were able to present a couple of my favorite concertos with the expected size of the concert hall and the fullness of most of the instruments. I believe the room was well treated with all sorts of acoustic panels, and there was 2.5 to 3 feet behind the maggies. It was a very enjoyable experience, especially the presentation on the string instruments. They just sound more real and natural than my monitor speakers. But with the piano concerto, the presentation seems to have a little less with the 'attack' yet the ambient of the hall was very good. And with other jazz pieces as well as some test tracks that contain more precussion passages, the 'attack' seemed to be satisfying (ie, I didn't feel the need of looking for them).

After coming back to reality, I started to search for reviews and used equipments for the new set of maggie 1.7i and the Naim integrated are way over my budget. I saw a review on 'enjoy the music' (I think) on the 3.6, the reviewer seem to commenting the maggies tend to have narrow sweet spot comparing to cone speakers: is this your experience? (I guess I'd also start a post in the planner circle inquiring users' experience too).

I'm not fully won over just yet. I wish there are some users of open baffle speaker within an hour drive that I can visit. Enjoy the remainder of the long weekend with your music.

[Zeev (PureAudioProject)]

Just a couple additions about the PureAudioProject drivers. Besides the basic Eminence Alpha 15, there is an updated version that uses a thicker stamped frame, and more importantly shorting rings in the voice coil motor. That should cut distortion significantly. The last, I want to call it a premium version has a cast frame (looks like from delta lite) neo magnets and shorting rings.  I haven't seen any specs on these new drivers, but they are made in cooperation with Eminence engineering.

The Neo drivers were playing at the California show. The passive crossover integration with the TB driver sounded good. Like most 8" full rangers the frequency response is tipped up on axis. Off axis, they were very nice. They also probably can take more abuse than a Lowther or Fostex unit.

I would build the system with  active DSP and crossover. The system is very modular lending itself to easy updates.

Hi Steve and everybody,

Here is the URL of our updated Alpha15 Neodymium drivers and their spec:
http://www.pureaudioproject.com/product/15inch-open-baffle-bass-woofers/
Spec: https://drive.google.com/file/d/0B36Kyv2xZFCtMGFMMHFmNS1YUjg/view

[Oktyabr]

Hi All,

Just an update on my search: I went to a local dealer to listen to the maggies. I spent about 30 minutes on the 0.7 and 90 minutes on the 1.7i. For sure, the 1.7i have a fuller presentation of an orchestra. Both speakers are driven by a Naim SuperNait2 (80w/ch). The amp and the 1.7i were able to present a couple of my favorite concertos with the expected size of the concert hall and the fullness of most of the instruments. I believe the room was well treated with all sorts of acoustic panels, and there was 2.5 to 3 feet behind the maggies. It was a very enjoyable experience, especially the presentation on the string instruments. They just sound more real and natural than my monitor speakers. But with the piano concerto, the presentation seems to have a little less with the 'attack' yet the ambient of the hall was very good. And with other jazz pieces as well as some test tracks that contain more precussion passages, the 'attack' seemed to be satisfying (ie, I didn't feel the need of looking for them).

After coming back to reality, I started to search for reviews and used equipments for the new set of maggie 1.7i and the Naim integrated are way over my budget. I saw a review on 'enjoy the music' (I think) on the 3.6, the reviewer seem to commenting the maggies tend to have narrow sweet spot comparing to cone speakers: is this your experience? (I guess I'd also start a post in the planner circle inquiring users' experience too).

I'm not fully won over just yet. I wish there are some users of open baffle speaker within an hour drive that I can visit. Enjoy the remainder of the long weekend with your music.

I chased mid range esoteric speakers in boxes for years including Snell, Dahlquist, Vandersteen, huge Polk Reference, Infinity Kappa, and my much beloved (and missed) Teledyne AR-9.  My road hit a detour when I heard my first pair of MMG, which I immediately purchased.  I added two larger pairs of Maggies to my collection that following year and was fairly pleased.  Yes, they were inefficient and no, they didn't produce the bottom octaves in the way I was used to, but something else was really going on with them in the way they loaded the room and presented such a large and effortless sound stage.  Eventually a move saw them sold and I started the hunt again.  My last pair of commercially made speakers were Martin Logan SL3, which I preferred to my most recent memories of the Maggies.  But I still wasn't satisfied and if Martin Logan can sell a pair of speakers for US$3000+ that DON'T make me 100% satisfied, then why not try my hand at DIY?

I tried a couple different single driver "full range" box designs which gave me a feel for what a small, specifically purposed driver could do and then I stumbled across some of the open baffle threads.  I read MJK's papers on OB, especially on the H-Frame, over and over again until I saw the printed words under my eye lids when I went to sleep.  Here is where you come in...  A member of the diyaudio forum (possibly here as well?), by the user name "gvimhoof" posted a thread about using Eminence Alpha 15's in H-frames with a small, full ranger on top in an open baffle, per MJK recommendations.  gvimhoof works at a place with not one but two concert halls and demo'd these speakers for his coworkers.  This is the thread that pushed me into making a ton of sawdust of my own and I've lived with 8" Audio Nirvana Super 8's over Goldwood GW-1858 H-Frames ever since.  I mostly listen to classical and jazz and built mine specifically with a pleasing reproduction of Charles Mingus' Big Band "Haitian Fight Song" as my target.

http://www.diyaudio.com/forums/multi-way/156713-mjk-ob-over-h-frame-finished.html

[ajmac]

Hi All,

Just that you know, I'm still working/researching on this design: 2 ways (to  3-ways if necessary) active OB that will not be congested when playing larger classical musical pieces.

Over the holiday, I visited Richard, Deborah and their Lowther + Alpha15a OB. (Thanks Richard for your hospitality.)

I'm convinced that the Lowthers OB, if setup well, can give a fairly good presentation for classical/orchestral music. It may not be the most powerful choice, but it certainly convey the amount of musical energy and emotion that I am looking for.

But I have this question in the back of my mind for a while, and it's just re-surfaced - regarding using the Lowthers on OB (or any other fullranger or wideranger with a whizzer cone): the frequency band that is covered by the whizzer cone, is it still dipole? Would that affect the presentation of sound?

[guest42212]

 > the frequency band that is covered by the whizzer cone, is it still dipole?

For practical purposes .
We measure and conceive drivers as ' rigid pistons ' ,
but even woofers have a big difference in front to
rear characteristics .   

[jostber]

You also have the Trio10 Mundorf speakers from PureAudio which are getting
some fine reviews. I am in the same situation as you with an L-shaped room and
family sharing. The smaller Trio10 size should make them easy to move. I have
been looking at these myself. 

http://www.stereotimes.com/post/pure-audio-project-trio10-mundorfamt-loudspeakers/

You should also think about the amp and speaker combination. For
your room optimally look for an amp that plays also great at low volumes. I
would look for a tube amp of good quality. This will give you a great lifelike
sound full of soul for your classical music. I have a similar setup now with
one SET amp (Transcription Audio) and a Push Pull amp (Bob Carver) which works
beautifully with my open baffles. Avoid high powered Solid State amps with low
sensitivity speakers for a room like this.

I would recommend some room treatment instead of DSP to get the most analog,
lifelike sound. I also have some Townshend stands for my speakers to ensure
that the music stays in the room, and does not move
to other rooms by vibrations through the floor and walls.