[Springbok10]

Round ten to SP Tech by a knock-out. You have a new customer. I'll e-mail you now to place my order. You can tell by my possession of original Allisons, that I am an old dude, so rush it, as I do want to hear these with my hearing still intact:) I must tell you that Duke, from whom I purchased my preamp in 2004, was a big factor, since I respect and value his judgement enormously. He is fairly unique in the industry, as you probably know. And any designer who would go to the trouble that you have, to explain and modify and put everything out there so coherently and honestly is certainly someone who deserves success and whose product I would be proud to own. Thanks again.

[ted_b]

So that, ladies and germs, was the first episode of "Bring Bob your bad room".  Bob scores a knockout, and Springbok10 is relieved of several annoying room anomalies (as well as some hard earned cash $).  Everyone is happy.


Bring on the next room please.     

[lonewolfny42]

Bob....

No worries my friends.  If there’s another speaker out there than can even EQUAL the Revs in regards to Springbok10’s situation, I’d like to know about it.  I ain’t scared…I’ll be glad to go head-to-head with any other design and compare notes.  I know what we’ve accomplished and I also know what other’s are doing – have known for a long time.  That’s WHY our stuff was designed as it has been.  Considering the long history of audio and the maturity of the market, you don’t push the state-of-the-art like we have unless you really do your research.

Bob is correct....he's got nothing to worry about....the Revelations are some kinda wonderful speakers....

[Duke]

Springbok10, congrats!  I think you'll be very happy with the combination.   Thanks for the kind words, by the way.  And thank you too, Bob.   

Duke

[dwk]

This is an interesting thread to me, as my evolution in system philosophy was driven by a similar room problem to Springbok. My quasi-dedicated room in the basement is basically a 7'Wx7.5'Hx16'L tube. I have good mini-monitors (Sapphire XL), but trying to make them work even acceptably was nigh on impossible - getting them out into the room away from the front wall ate up basically the entire room, and even then you can't get much if any separation from the side wall. Without treating the entire room with 4" panels, I just didn't see how it would work.

Thus began my search for a better way, which lead to controlled directivity.

I ended up going the PA cabinet route, but the Yorkville U15's are pretty unique PA cabinets. As long as you're not afraid of a bit of EQ (needed in my case anyway due to the room modes from the 7' and 7.5' dimensions) they can comfortably stand beside hi-fi speakers anywhere close to their price point (IMHO, of course).  Other than that, though, my approach/solution pretty closely mirrors what Bob discusses here.

-The U15's are placed directly in the corners
-First reflection points on the lateral walls and the front wall have a single panel absorber (the one between the speakers was surprisingly beneficial)
-In my case, the U15's have no BSC built-in, so I didn't need the additional eq to correct power response due to corner placement

Is this as good as having 1000sq ft of space? No, but considering the constraints, I'd say it works pretty darn well. In particular, it does do a pretty good job of presenting soundstage and imaging, which are typically tough in small rooms.  It misses a certain sense of stage size/scale compared to larger environments though; the best analogy I can come up with is that it's similar to the difference between watching a 42" HDTV from up close vs a projector from farther back - same resolution/detail, same subtended angles, but  we 'know' that one is 'bigger' than the other. 

One thing in particular that continues to catch me off guard on occasion is how balanced the sound is out of the sweet spot and out into other rooms. This is of course largely due to the extremely uniform power response provided by corner placement. In my case the U15's are 60x60 dispersion up high broadening to 90x90 lower due to the corner placement, so there is a bit of a taper in the response. This is a 'season to taste' type of thing, but it's frequently the case that a bit of a slope to the power response is subjectively beneficial.

About the only thing I see needing a bit of clarification in Bob's description is with regards to acoustic treatment. The corner placement + controlled directivity does greatly mitigate the impact of the side wall immediately adjacent to the speaker. However, the *opposite* side wall is still a potential source of early reflections - i.e the left corner speaker bounces off the right side wall before arriving at the listening position. This obviously will depend on the geometry and size of the setup. In my case where I'm so close to the side walls, I 'needed' to place treatments to absorb the first reflection from the opposite corner speaker. This also is why the panel between the speakers helped - the oblique reflections went off the front wall, then off the opposite side, then to the listening position.  It's a bit tough to judge from Springok's pictures how much of this will be a problem in his setup, though.

[Duke]

dwk wrote: 

"However, the *opposite* side wall is still a potential source of early reflections - i.e the left corner speaker bounces off the right side wall before arriving at the listening position."

Psychoacoustically, this is not a problem.  First of all, there a much longer time delay to the opposite sidewall reflection, which is beneficial.  Also, because of the way the ear/brain system processes opposite-ear arriving reflections, the fact that the reflection arrives at the opposite ear first causes the ear/brain system to classify it as "reverberant energy" instead of "coloration of the original sound".   In other words, in most cases it will be overall beneficial instead of detrimental.

Of course if you desire, the opposite sidewall reflection can still be treated with either diffusion or absorption, just like the same sidewall reflection in a conventional setup.  I like to use a lot of toe-in with waveguide speakers, and I've never felt the need for sidewall treatment aside from extreme situations like audible slap-echo (which is really a different problem anyway).

An additional benefit of the strong toe-in implied by corner placement is a wider sweet spot as the listener moves off centerline, because the listener will be moving more on-axis of the far speaker and more off-axis of the near speaker.  At least, I presume that's the case with your 60-degree pattern loudspeaker; my experience is with a bit wider pattern. 

Duke

[ted_b]

I love imaging and have typically espoused more-drastic-than-normal toe-in for most of my speaker life.  The Revs are toe'd in quite a bit (see my gallery) and I love them in that setup.  And yes Duke, the fact that the right speaker stays on-axis as you move left is a nice sweetspot plus, considering the horiz dispersion of the waveguide anyway..

[rydenfan]

So that, ladies and germs, was the first episode of "Bring Bob your bad room".  Bob scores a knockout, and Springbok10 is relieved of several annoying room anomalies (as well as some hard earned cash $).  Everyone is happy.


Bring on the next room please.     

Bod and I have talked a few times about some Continuum AD's. This thread has very much spurred my interest.

[alotaklipsch]

Springbok, congrat's, I wanna tell you, I am running my Rev's with 60 watt custom KT88's, not enough power, but, wonderful sound.  I will have my custom Dodd's in the next few weeks, and maybe a custom spectron too.  I will let you know.  If you are in the Chicago area, meybe we can get together, and you can bring your amps.

Best

Steve

[Springbok10]

Thank you, Steve, but I live in Connecticut and my monobloics weigh 125 lbs each:)

[alotaklipsch]

You are welcome, wish u were closer, cause, even w/60 watt pp's they sound frikin great.....I am sure you will be smilin, soon.  Hope all goes  smooth.

Steve