[ooheadsoo]

This is not really a review, but a jumble of past and present blog-like thoughts.  Bob’s request for more “reviews” to be posted prompted me to find a couple of posts I remember making in the past, and weaving them into something ever so slightly more formal.  Clearly this is still nowhere near a formal review, but I hope to convey within it some of the thoughts and impressions I have had in the last 2 years on SP Tech speakers.  My past comments are slightly edited.

Back in the middle of 2006…

I finally made time to finish the kit of this speaker [SP Tech AV-2.]  It is slightly modified with vinyl tiles on the walls of the cabinet, some black hole 5, and some spray on damping material designed for rattling car panels I learned about from one of thechairguy's posts.  I have 1lb. of acoustastuff polyfill from partsexpress per speaker.  Here are a few brief notes after a day of listening.

I listen between 1m to just over 2m away.  In my 14.5ft.x16ft. room, I hit peaks just exceeding 100db.  I may have played it louder at other points, but I wasn't measuring.  At no point did the speaker sound strained.  I am powering it with an Odyssey Stratos and a CIaudio VPC1 (passive preamp.)  Source is the non-oversampling DDDAC1543 with 16 chips in parallel, extra voltage regulator mods, all premium parts, battery powered, fed by a emu1212m pro audio sound card.  The Stratos is said to put out somewhere around 150+w@8ohms and approximately doubling into the 4ohm load of the AV-2, so has somewhere around a ballpark of 300w available.  Dynamics in spades, it makes big sounds with a natural ease.  Could be the even power response afforded by the waveguide, I suppose.  I watched Fearless and it was wonderful.  Never sounded strained for a moment, I had confidence these speakers could keep up.  The woofers were barely moving.  Visually, they didn't seem to be moving at all.  Putting on a 50hz test tone at 80db made the woofers move about 2mm peak to peak.  Strong distortion could be heard by my ears starting well before this point, but this is not program material. 

The funny thing is I'm hearing more detail from this speaker than my last monitor, the mbow1 designed by Dennis Murphy.  Lots more detail.  It must be in my head, except I can't quite convince myself that this is true.  Take it for what it's worth.  I'm hearing lots of things I haven't heard before.  So many, I can't believe my ears, really.  Was I paying such poor attention before?  In any case, I'm getting lots of detail from this speaker, and the imaging is solid. 

Tonality is quite neutral and natural.  String quartets sound like they're in my room, at last.  Between my brothers and I, we play all the instruments in a string quartet (besides a few others) many times over, and I have access to a few dozen of each instrument, so I'm fairly familiar with what they sound like up close and personal - such as in a quartet setting, and this speaker can do it.  Piano is also done decently, thanks to the dynamics.  Upper piano harmonics seem intact, something that was fishy with my past speakers.  Waveguide in action?  I don't know.  Could be.  I still have the same bass problems I have had with all box speakers in my room, in the same frequency ranges, which I deal with via EQ, which works fairly well for a large sweetspot.  I've got a dipole I'm not using, which had different bass problems - not quite as extreme, but still problematic, just the same. 

The tonality of the speaker remains relatively constant along the horizontal plane, which is nice.  Big reduction in the killer early room reflections in the higher frequencies, no nasty rippling combing effect as I lean left and right.  Unfortunately, the imaging is very sensitive to position and shifts far left and right along with your head position.  Still sounds good, but the image is way off, with all the L/R mixed channels sliding in the direction of your position relative to the center.  The one thing the waveguide did not solve for me.  I'm now very confused regarding how you achieve that effect with a speaker.  All in all, I'm a happy camper, although I may never build another speaker cabinet again.

That was in 2006.  It is now 2008 and I am on the verge of acquiring a pair of SP Tech Timepiece 3.0.  I have spent the last 2 years listening to my SP Tech AV-2 nearly every day.  My listening habits have changed, greatly.  When I built the speakers, I had to use them for critical listening, in the sense that I was using them to playback music that I needed to analyze for papers I needed to write in the pursuit of my degree.  Music for enjoyment was on the back burner.  Since the completion of my degree, I have used the speakers for personal enjoyment almost exclusively.  I have also listened almost exclusively off axis except for when critically listening to a mix.  This means that insensitivity to room interaction and tonal and dynamic accuracy are much more important to my habits than imaging.  Although realistic imaging is very high on my list of critical listening priorities, very close to the top of that list, I simply do not have time to do a lot of critical listening, where I am focusing every pore of my body on finding every flaw in the mix.  Several equipment and placement changes have occurred.  I changed the orientation of the speakers to fire down the long side of the room and moved them closer to the side walls.  They are currently about 2 feet from the sides and 3 feet from the back, and I can sit from anywhere between 1-3m away on a rolling office chair.  Having them this close to the corners has helped the bass response, which, in my room, is quite deficient.  Due to the directionality of the waveguide, I have not heard any penalties in tonality and soundstage.  I have changed my preamp to a McCormack passive and the power amp to an AVA 550EX.  I played with acoustic room treatment for a little while.  I got rid of my first reflection point fiberglass panels and now have 2 batts of r-13 and (4) 2” 3lb.pcf 2’x4’ rigid fiberglass panels stacked in one corner of the room, and another batt of r-13 in another corner.  A third corner has a large roll of foam, roughly 4.5’x7’.  I don’t hear any significant penalties in removing the first reflection point treatments, and the smoothing of the bass frequency response was noticeable.  I would move the speakers even closer to the walls, if possible.  I also have 4 Gik D1 diffusors on the rear and rear side walls.  The AV-2 pours forth tone and detail beyond the capabilities of my past speakers, of which the best was the Dennis Murphy designed MBOW1.  The AV-2 is tonally neutral and reveals detail, rather than spotlighting it.  I have heard more “tone” only from speakers with grossly distorted frequency responses, which push parts of the spectrum out beyond the others, giving an illusion of increased tone. 

But wait, that’s not quite true.  There was a speaker I heard in the past that impressed me greatly and, in my opinion, it eclipsed my AV-2 in every way.  That was the Nuforce S-9.  Here is an edited version of what I wrote about the S-9 in the past:

The speakers[s-9] sounded really nice, large banks or swathes of sound when called for, like with xylophones, which sounded similar to how they ought, hearing the diffuse ringing of the bells, and not just the striking of the mallets on the wood blocks, and pinpoint when called for, such as with cymbals and brighter instruments.  I'm a complainer, privately and in the safe anonymity of online forums, and in this case, there was just nothing much to complain about except for the room's bass.  [Even then, the setup’s bass was on the large, ground shaking, and bombastic side, which in retrospect is greatly preferred to the other way around – at least the way it sounded in the demo.]  They were very detailed, and in the words of someone else, holographic.  Again, to me, my mind couldn't associate the sound with the speakers because the projection of the sound was so large, that it couldn't have been coming from the speakers.  With some light jazz trio work playing, listening from outside the auditorium, I could easily be fooled into thinking it was a real trio playing inside. 

Actually, one of the things that pleased me was how close the SP Tech AV-2 speaker kit I bought and assembled got me to the sound of the S-9.  The S-9 did many things better.  Despite the AV-2 kit's 8" driver MTM arrays, and a much, much larger visual presence, the S-9 played (much, much how many times can I say much?) louder effortlessly and presented things with much larger images (not lacking in specificity or precision, but with a larger presence, closer to real life.)  Imaging was more detached from the speakers than the AV-2.  It's hard to compare though because of the very different natures of the two listening environments and the fact that there was not one recording I was able to listen to on both systems.  Nevertheless, the AV-2 kit got me close for a fraction of the cost.  These speakers deserve a good listen with recordings you are very familiar with - hopefully the RMAF room will be treated for bass.  It may be interesting to note that although my own system is reinforced with a subwoofer that is roughly -3db@20hz, very little music actually reaches that range; probably nothing that we listened to came closer than 41hz or so for the low E on a 4 string electric bass.  Nevertheless, what bass there was had a much stronger presence, force, and impact in the S-9 demo.  Some of the weakness of the bass in my system I attribute to my own room, which is not great, either, but that doesn't detract from the very dynamic bass in the S-9 demo.  I would be more than happy to own the S-9 and experiment with bass traps and/or EQ in the demo room, if the room were mine.

[ooheadsoo]

If I had one criticism about my SP Tech AV-2 experience, it would be that it does not have a full 3d holographic sound stage in normal circumstances in my room.  I believe most of it is room related, but much may just have to do with the nature of box speakers, which dictate that the imaging sweet spot be small.  It was my unrealistic dream to find an affordable speaker that had the dynamics of a jackhammer and the finesse and detail of an electrostatic, but also imaged like an omnipolar or linesource in a big room, where you can walk around and still get decent stereo separation.  Ultimately, I decided to sacrifice fine holographic imaging for immaculate dynamics and detail.  If I had a room that could support the big swathes of sound that I heard at the S-9 demo, I would be ecstatic.  The only other real "problem" I have with my stereo is that the bass response is really bad, even with the GR Research subwoofer that is rated -3db@20hz.  I have never been able to achieve a full lowbass and midbass in this room.  The null in the bass seems to run through the entire room unless you're within 1-2 feet from the walls.

Those S-9 comments still stand and that sole listening session I had of the s-9 left a strong impression on me.  In retrospect, what wouldn’t I give for bass response like I heard at that demo??  That great earth shuddering monstrous moaning bass is preferable, to me, than anemic and lean bass.  It was never for a second “one note” bass.  It was still finely articulated and had great tone.  It, without a doubt, had all the live verve you needed.  With lean bass, you get the tone but none of the weight, and, for this bass guitar and trombone player, real bass has to move some AIR.  For this reason, I look forward to the arrival of my Timepiece 3.0 with great anticipation.  With the TP3.0s combined with closer corner placement and some more room treatment (if I can afford it,) I hope to minimize the bass response issues my room has.  Lastly, the TP3.0 I will receive will be upgradeable to the Revelation=Mini, and after all the raves about the full Revelations, a pair of speakers I will likely never be able to afford, I can only imagine with even greater anticipation what the Revelation=Minis will sound like.  Bob told me that he would be happy to own a pair of them as his only speakers for life, but there are two things to keep in mind: 1) He hasn’t built them yet, and 2) He hasn’t even had the chance to build a pair of speakers for himself, yet!

Please support this gentleman and his excellent products by keeping the buzz and posts alive.

[Carl V]

I too own the AV-2 speakers.  And for the most part I'd agree ooheadsoo.
Damn great value speakers.

I have 2 different XO's...they differ in both components & ever so slightly in design.

I have also used and still use an Autoformer....and find it's effects mostly positive...
more so with tubes amps.  I have driven these speakers with many amps...many.
I'd be curious to see both an Impedance-- Phase & Freq. Response Graph a'la
Sterophile.

I've lugged these speakers to a few friends homes for A/B listening sessions.  I've had
a few guests over for critical listening as well.  Nobody has said they dislike the sound.
Most have said damn good....& "how much were they?"  Some have commented on
their size.  Those that haven't own floor standers or larger Monitors Such as Harbeth 40
& AN-E or SP-100 Spendor.  In other words they aren't small lifestyle speakers.

They have not been shamed by A/B switcheroos with the AN-E,  Harbeth's Or Living Voice Avatar.  All these speakers are more expensive.  But all are good "musical' speakers which pair up nicely to tubes....as do the SP AV-2's.  All have +/- 's and you need to decide what sort of speaker works best for your needs & finances.  But I can tell you this the AN-E owner was
a little miffed.....crestfallen.  The Harbeth & Living Voice guys preferred their speakers.
But check the $~price of those speakers....are you surprised.  They were preferred over
Paradigm, Monitor audio & some others.  They were neck & neck with Northcreek Rythym
 a SEAs MTM & a DIY Partsexpress MTM.

Ultimately, the AV-2 have done best with P-P EL-34 or 6L6 stereo amps passively bi-amping
in a vertical manner. Autoformer at 2x hookup.  They did really well with a Response Audio
SPM-40 mono block amps....& when the autoformers went into the mix wow!
A passive  1st order inline filter @ 65 or 85 Hz helps both speakers &
Amps....I bring in stereo subs underneath.  Either Sealed Tempests or 15" U framed design.  They have
also done quite well with cj mosfet amps, McCormack DNA .5 & 1.0....to be honest they
do well with most good amps.  They can take a ton of Power.

I have found that they sound best either crossing in front of the listener or behind.
In other words Don't listen with them firing straight at you or firing straight into the room.
I have found that they 'gel' when you sit at least 9 feet away.  And I have found that I
prefer them in the Cardas set-up.  Whereas my friend with the AN-E prefers them a bit
closer to the walls as ooheadsoo seems to prefer.  The gentleman with the Harbeths
prefers the AV-2 & his 40's 2 feet from the back wall & 4 feet from the side wall with
their axis crossing in front of him.

They do tone~timbre well & soundstage fairly well.  They play loud enough for most people.
If I was playing arm-chair quarter back, I'd like a better tweeter.  Because when playing
above 95db they become strained....on some program material.  But this is nit-picking.  I am sensitive to this.  Bob & Karsten seem to think the new Mundorf XO might eliminate this
loudness problem. I don't know.  I've already done 2 XO designs.  One was ever so slightly
warm & less tipped up....the other a bit more 'flat' perhaps.  I like 100% wool inside.

I would also like to mention that SP packs and ships their speakers incredibly well.
Bob has always been a pleasure to communicate with & to do business with.
I have heard most of his other speakers in Show conditions & never felt they sounded bad
in those show conditions.

[ooheadsoo]

Since these speakers are so heavy, I don't anticipate doing any A/B switching with the Timepieces, when they arrive in a few months.  However, I am eager to hear the differences.  The price on the TP should be more in line with many of those speakers you have mentioned, particularly the Harbeths.  Unfortunately, they are probably not as tube friendly by a fair margin.

One thing I would amend to my initial impressions - the AV-2s are very dynamic, especially compared to my previous smaller speakers - but they are not the final word on that by any stretch.  The S-9, for example, would trample them.  However, a casual observer may observe that the S-9 just has 2 dinky 6.5" woofers and dismiss my comments based on previous experience with speakers of those dimensions.  I would urge you not to do so.  When I heard the S-9, they were playing in a hotel banquet room roughly 30'x100' (if not larger) and were belting out live level sound.  It wasn't just playing "loud enough," it sounded like the real deal were on stage playing.  An online acquaintance who auditioned the S-9 at my urging compared them to something to the effect of 11 foot tall giants.

[lonewolfny42]

ooheadsoo...

Since these speakers are so heavy, I don't anticipate doing any A/B switching with the Timepieces, when they arrive in a few months.  However, I am eager to hear the differences.

Their about 65 lbs. .....not too bad to move around....
I've "carted" my TP 2's to a few Raves....

You will enjoy them.....