[mick wolfe]

Excellent review that captures the strengths of the Spatial design. Well voiced, efficient and tube friendly(solid state as well) inviting all genres of music to the party with ease.

[rebbi]

Rebbi,

Very well done.  Clearly the speakers engaged you and you engaged this reader right out of your opening. You provided a good balance between technical and emotional and captured the OB excitement.

As someone who has done a fair amount of writing, I found myself thinking "I want to write like that".   

That's so nice of you!   

Thanks. I get the most joy from knowing people get something out of what I write.

[Vedder323]

Fantastic review.

Thanks for sharing!

-Ron
New Record Day

[erniek]

Thanks for the thoughtful review. Almost makes me want the M4's instead of the desired M3's.
Great job, anyone got M3 review lined up?

[Manolo]

Delightfull and superbly written! Echoes my findings with my M4's, specially in the sense that I also have them in a small room. I would suggest getting rid of the plastic footed "spikes" and get real spikes, though I guess you would have to use brass cups to protect the wood floor. I got more bass definition with this tweak. And due to their bass radiation pattern, they are easy to merge with a sw if you leave them full range using the high level connection..... and lastly, one gets what is there on the recording including all the sibilance nasties in that Diana Krall recording and an impressive airy and spacious soundstage of course.......

[rebbi]

Delightfull and superbly written! Echoes my findings with my M4's, specially in the sense that I also have them in a small room. I would suggest getting rid of the plastic footed "spikes" and get real spikes, though I guess you would have to use brass cups to protect the wood floor. I got more bass definition with this tweak. And due to their bass radiation pattern, they are easy to merge with a sw if you leave them full range using the high level connection..... and lastly, one gets what is there on the recording including all the sibilance nasties in that Diana Krall recording and an impressive airy and spacious soundstage of course.......

Thanks for the kind words, Manolo!   
I do have little metal discs for use with spikes on hardwood floors. Perhaps I'll try the stock spikes that Clayton provided and see if I can hear a difference.

[Bemopti123]

You people are like audio drug pushers!  Thanks for the excellent review.  I am contemplating either using what I have to have a hi efficient speaker system for my recently acquired Bakoon AMP12R.  If I was in the market for a pair of hi efficiency speakers, Spatials would always be on my top of my list. 

Paul

[JLM]

rebbi,

Terrific review.

Have you had an opportunity to hear any of the Hawthorne Speakers?  Nearly identical in design, they also use Eminence drivers, and I've known Darrel before he started building O.B.'s.  So I've heard many of his earlier designs, but I have to tell you I've never been a huge fan.  His Silver Iris drivers lacked detail (the Sterling Silver was better but not perfectly detailed and not cheap) and the imaging discontinuity between the tweeter and 15 inch coaxial mid/woofer was bothersome.  But my biggest problem with all dipoles is the diffused "wall of sound" presentation.

From the New Record Day video the concept of "controlled directivity" is mentioned, but not described (sorry haven't looked further into the manufacturer's writings).  From his and your review it doesn't seem to be strictly followed in terms of setup (as I understand it from Leune and Geddes) where the speakers should be severely toed in (to cross in front of the listener even sitting near-field).  This avoids side wall reflections that have less than 0.11 ms delays that smear imaging.  Wonder if you've found severe toe in improves on the "wall of sound" problem I've noticed in the past.

[rebbi]

Hi, JLM,

Thanks for the kind words about the review!

You raise some interesting questions and some of them would probably be best answered by Clayton, himself, but I will offer the following:

The following quote comes straight from the Users Manual. It assumes that the speakers have had 24 hours of warm-up time. Then, you do your initial positioning. Then, after a month, you fine-tune your positioning further. I actually haven't done this second fine tuning, yet, because I've been quite satisfied with where they are. Anyway, here is what the manual says:

B. Initially, set up both speakers at 24” distance from front wall and toe in to where the speakers are perpendicular to the left and right ears. Listen for an hour or so to get a baseline for how they sound.
C. Then move closer and farther from front wall between 18 and 36 inches - moving both speakers equally. Find the best combination of deep bass output and soundstage presentation.
D. Experiment with distance from side wall if possible to find best lower midrange integration. Closer placement to side wall increases level in the 200 to 800Hz range.
E. Let the speakers run-in for a few weeks and then revisit positioning to fine tune. Toe-in adjustments allow the tuning of imaging and soundstage parameters. After final positioning is determined, use the tape measure to accurately match left and right channels. Measurement points are the two front corners of the top of speaker from the front wall. This techique takes toe-in angle into account. Call the factory for additional assistance.

At one point, Clayton emailed me when I was asking him about tow-in angle. He said that, typically, a fairly shallow angle of around 22° works well (given that every room is different, etc.). And, that's about how my speakers are currently positioned.

If you go to the website, there's a pretty good explanation of Controlled Directivity as it is implemented here. The idea is that the speakers are designed to take deleterious reflections out of the equation as much as possible, and that, as I mentioned, the forward dispersion of the speakers is only about 80° in total.

I have not found the speakers to give a "wall of sound" or "in-your-face" kind of presentation. Rather, they seem to be pretty true to what's on the recording, and do not artificially swell or inflate the soundstage. If the recording warrants it, you will get an immersive, wall-to-wall kind of presentation. But, if the nature of the recording is rather "dry" and immediate, such that there is very little sense of space or reverberation, then the presentation will hang between the speakers, as you'd expect. To my mind, this is pretty close to my fantasy ideal: a speaker that is capable of throwing an enormous, immersive soundstage and yet does not impart that artificially, nor does it sacrifice imaging specificity and placement of individual instruments, etc.

To give you a not entirely apt comparison: a good number of years ago, when I first got back into high-end audio after a long hiatus, I owned, for a while, Ohm Walsh Micro Tall speakers (and later the Ohm Walsh 100). They are a "pseudo-omni" design, radiating sound almost 360°, but attenuating the radiation in the back to reduce front wall reflections. Some people absolutely adore their presentation: everything sounds rich and room filling and you can hear the stereo effect no matter where you sit or stand in the room – it's pretty uncanny. But I became frustrated with them after about a year, because the imaging seemed vague to my ears and I couldn't get used to it.

The thing with the Spatial M4 is that when the recording warrants it, you do get that "room filling" quality and it's wonderful. But, again, it doesn't impose that kind of big, amorphous sonic signature on everything and even when the soundstage is huge, you can still locate individual instruments and singers if that's how the album was recorded.

As far as the other speakers you mentioned, I'm not hugely technical, I will say that on the New Record Day video, Clayton talks about working with Eminence over the course of a couple of years to develop drivers that responded exactly the way he wanted for this application. He definitely seems to be a science/engineering/measurements kind of guy, but he also has good eears and knows what music sounds like. 

[Don_S]

Here is a picture of how Clayton set up his room at T.H.E. Show Newport Beach in 2015. Note the positions relative to the walls and and the toe-in.  Also note the carpet.  Less vomit-inducing than CES or other venues. 

[JLM]

Hopefully Clayton will have his speakers at Axpona this year as I'm planning on attending.  I hope to hear the sort of imaging I'm familiar with.

That toe-in appears to be insufficient to fully eliminate immediate reflections from the adjacent side walls as LeJeune and Geddes recommend for controlled directivity ideals.

And before Axpona I'll try to read from his website.

[Manolo]

I have tried various loudspeaker angles in my near field setup -small room 11'x12'- and found that a minimum rake of 10 deg. or so,  works much better in that room.

The soundstage is huge when it is in the recording and instrument delineation is pinpoint, not diffuse at all. 

[borism]

JLM I am wondering if the decreased toe-in angle compared to the Geddes - LeJeune recommendations is a compromise that takes into account that for open baffle bi-poles with greater toe-in the distance to the side wall (for the back wave to bounce of) gets diminished (in most rooms). Duke gets around this in his newest designs by aiming the rear - ambient drivers at the ceiling (LCS - late ceiling splash).

[JLM]

I'm sure some of the physics change between direct radiators and O.B. regarding imaging.  According to Duke a 15 inch driver goes directional around 500 Hz while the NewRecordDay video mentions 800 Hz crossover to the sealed compression tweeter.  I really need to do more reading of Clayton's site.

I'm well aware of Duke's (actually Jim Romeyn's) Late Ceiling Splash as at Duke's recommendation I've using a 1.125 inch soft dome tweeter in LCS configuration for each of my single driver floor-standing speakers for the last few months to great effect.

[nicoch]

beware 12/15" coax are an old story....cannot work well !
all horn user know this !

[sonicboom]

That toe-in appears to be insufficient to fully eliminate immediate reflections from the adjacent side walls as LeJeune and Geddes recommend for controlled directivity ideals.

Geddes' and Duke's speakers being monopoles, have a cardioid radiation pattern with considerable radiated energy to the sides and even the back at mid-low frequencies. Dipoles having a figure 8 radiation pattern, don't throw much energy to the sides. This, I'll assume is how the Spatial's can be placed closer to the side wall without much detriment to their imaging.

[JLM]

beware 12/15" coax are an old story....cannot work well !
all horn user know this !

Please explain.

[JLM]

Geddes' and Duke's speakers being monopoles, have a cardioid radiation pattern with considerable radiated energy to the sides and even the back at mid-low frequencies. Dipoles having a figure 8 radiation pattern, don't throw much energy to the sides. This, I'll assume is how the Spatial's can be placed closer to the side wall without much detriment to their imaging.

I'm aware of dipole radiation patterns, but if they don't radiate to the sides how do they create a horizontal soundstage?  It would seem that the Spatial Holograms would seem to function as both dipoles (below roughly 500 Hz for 15 inch drivers according to LeJeune) and direct radiators above (note that the sealed tweeter is crossed over at 800 Hz according to Clayton).  Note that leaves about 5 octaves in dipole range and 5 octaves in direct radiator range.

The site really doesn't have much information, but I did catch that both 15 inch drivers are mid-woofers.  I'm not keen on two sources covering the same frequencies past bass notes, unlike the Hawthornes that have a 15 inch woofer and a 15 inch mid-woofer coaxial driver.

[nicoch]

HI JLM I fast quote some for you ,in short is fisic ! 12/15" too big , horn too small . for search for altec 604

"They can work well, but not that well. The waveguides are always too small and this causes unrecoverable problems at the crossover
Lynn with a horn loaded co-axial you would be correct that you would create some strange diffraction patterns. And loading the driver that way also has its own issues with the straight edge over the cone driver. If the cone was used as the horn as Radian does then you could do something that conceivably would work but I don't see that done much. There is always some discontinuity where the cone meets the horn and the difference in angle between the cone and horn that will cause some type of diffraction. "
"The problem with a 15" coaxial is that the horn can't be big enough to go down to the woofer before it reaches cone breakup. At least that's the situation with the 604. A twelve might do it. I haven't heard them myself, but I understand in the world of Tannoy the 10" is the one that really carries it off. Put them with a VLF driver and you'd really have something, I think.
Tannoy has the design edge for horn size, I think, using the cone to load the treble, but I always thought there would have to be some intermodulation distortion being generated by that arrangement. I listened to a Tannoy red (or silver or black--I'm just going by the date) 15" long ago. It was my introduction to palpable realism for voice in speakers, but the guy had only one and I didn't buy it. I had a Jensen G610 back in the day. It had serious midrange coloration. I listened to Altec 604's for years; don't know how, I can't bear to have them on now. I'm keeping them only to try crossover tweeks on them eventually."

[JLM]

Agree that it's a stretch to mesh a 15 inch driver with a tweeter, but with the stated crossover of 800 Hz, it shouldn't be too bad.  Mis-matched dispersion is exactly what I heard from the Hawthorne 15 inch coaxial drivers, but as you say much well resolved with their 10 inch coaxial (which is no longer in production).  And BTW I'm a Tannoy fan too.