Harbeth 30.2 in-room, real-time measurements!
 

Okaaay....now that I've settled in with the Harbeth 30.2s, have 'em set up on the stands the way I like, I thought it was time to break out good 'ole Room Equalization Wizard (aka REW) and start doin' some measurements with an end ultimately to doing a DOE (Design of Experiments) to optimally integrate my REL R-305 with the 30.2s

The 30.2s are on Resonant Woods "Curved Series" maple stands using Brook Jensen's (of Resonant Woods) hard phenolic ball feet screwed-down & locked into the 1/4-20 threaded inserts in the bottom of the stands. The stands are resting on a particle board platform that has been stained with black Varathane urethane stain.

The speakers, stands, ball footers and the stand platform are shown here:
http://photos.imageevent.com/puma_ca...th%20Setup.jpg

The phenolic ball feet, which are very hard (same material as billiard balls), function analogously to speaker stand spikes in that there is a very small contact point between the phenolic ball-footer & the stand platform; they are leveled and very stable. The function of the particle board platform is to provide a firm, stable, non-rocking & "non-resonant and non-ringing" platform for the stands to sit upon on the carpet (this is my living room, not a man-cave). I tried many different materials, from regular wood to porcelain floor tiles to travertine stone, and a common hard dense particle board platform simply sounded the best.
The phenolic ball footers on the particle board platforms are shown.
http://photos.imageevent.com/puma_ca...footer%202.jpg

The Harbeths are coupled to the Resonant Woods stands with four 1.5" square pieces of beeswax cloth at each corner. Additionally, there is a small 4" X 1/2" strip of beeswax cloth on the rear support rail at the back of the stands. The beeswax cloth serves to couple the speakers to the stands, as well as provide a "constrained layer"- style damping. The stands are "open top" so that the cabinets can do their Alan Shaw "tuned cabinet resonance" thang. The beeswax cloth also couples the speakers to the stands so well that you can practically lift the stands by lifting the speakers. Moreover, it sounds really good.

http://photos.imageevent.com/puma_ca...n%20Stands.jpg

With that, I set up Room Equalization Wizard and did a very quick first-pass test sweep, just to check that things are working with the REL....
http://photos.imageevent.com/puma_ca...32.06%20PM.jpg

Not bad for a very first pass just to check settings and gear.

Next, I'll see if I can smooth out some peaks and nulls and get the response above 4K up a skosh...

More later, stay tuned....

Stephen... great system, photo and facts. I have a suggestion; if you put a single Stillpoints Aperture Panel II Panel between your windows, you would be gobsmacked. I know, because I am. :eek:

Thanks for the suggestion, Ivan. I'll consider it as I've heard good things about them also from Caelin and Stirling Trayle.

Actually, you can't tell very easily from the photo, but those windows behind my half-wall are opposite a very deep stairwell that goes down to the front door. So, I don't know how effective this panel would be on the wall on the opposite side of a deep entry-way stairwell.

Also, they are pretty pricey at $800 each. If I put up some more acoustical treatments, I think I will be installing a few GIK Acoustics Impression Diffusor panels of this design....

http://photos.imageevent.com/puma_ca...37.28%20PM.jpg

My space is quite unorthodox in that is not at all a rectangular "man-cave" type of room with four walls; its very open in a number of directions; behind the half-wall that is behind the audio rack, there is a deep stairwell that leads down to the front door, and off to the right of the audio rack is another open area with stairs which leads down to the deep stairwell. Also, there is effectively no back wall for the left speaker...just a long hallway, so I have actually have to be careful of the room becoming over-damped from acoustical treatments. I got four of the GIK Polyfusors from Keith (KMC45), and put all of 4 of them in the listening area, and they completely sucked all the energy out of the room; it was too dead-sounding.

Right now, I am using the two GIK Alpha 4As you can see and one of the GIK polyfusors, and overall, things are pretty well-balanced. What I currently don't have problem with are the high frequencies being too energetic; actually I'd like to get the frequency response above 7 KHz up about 5-6 dB.

We'll see how things turn out as I delve into speaker placement, sub settings and all...

Thanks and cheers,
Stephen.

As starting point before taking some base measurements in preparation for my new DOE for the 'Beths, today I did a soundcard calibration for the Soundcard in my 2015 Macbook Pro. My setup uses a NIST-traceable Dayton calibrated mic (with the mic calibration files for 0°, 45° and 90° provided) and an M-Audio MobilePre mic USB mic preamp.

I ran the Soundcard calibration routine and obtained this result. I think it looks pretty good based on the info from the REW forum...

http://photos.imageevent.com/puma_ca...ion%20File.jpg

Stephen,

I'm curious - have you had Stirling Trayle out to your room and perform his magic? Or know others that have?
I've been considering using him for a day (once I have some panels up on my back wall). I've been reading about him for years: Audio Systems Optimized
I'm not sure what he charges, but guessing it's at least a few $100/HR. I know my system could use some tweaking.
I believe you're in Castro Valley - as I'm in Danville, Stirling is based out of Petaluma, so all pretty much local. Anyway - system looks fabulous. :thumbsup:

Hi Ventoux (sorry I don't know your real name),

I haven't had Stirling out to my house but I went to a talk he gave for the SFAS meeting in April.

IIRC, Stirling charges $2000/day for setup and usually most "jobs" take two days.

And Stirling is local, but he travels a lot, right after I met him he was about to head to Asia for a while....

If you'd like to meet up some time and listen to each other's systems, let me know.

Cheers and regards,
Stephen

^^

Great - Ya, sounds like a lot, but, I think I paid that for 1 of my power cables... so.
Yes, we'll have to met up, I defiantly have lots to learn. I'd be curious what other systems sound like, and what others would think of mine. All about the journey :)

Cheers -

Ryan

Sounds good, Ryan, thanks!

So, this is where I'll be heading with my "experiments" with the Harbeths...a Design of Experiments (aka DOE) to fine-tune the in-room response.

Some of you may remember this study from back 2011 when I did it for optimizing my Dynaudio Contour S3.4s (oops, can I say that in a Harbeth forum? :p).

Below is the ANOVA table and Leverage plots in JMP 10 for the 20 Hz response based on the DOE.

http://photos.imageevent.com/puma_ca...Grab%20cap.jpg

The prediction profiler telling me where to set the Sub's controls for maximal response at the room mode peaks and nulls.
http://photos.imageevent.com/puma_ca...ler%20plot.jpg

And, of course. the surface plot for correcting a 155 Hz mode...;)
http://photos.imageevent.com/puma_ca...ponse%20II.jpg

For the 'Beths, I'll probably be also looking at subwoofer position relative to the corner walls its sitting in. I'll use distance from the two walls as the continuous data variable.

I'll be using JMP 14 and a Custom Design so that I can add quadratics to the model to examine curvature in the functional responses.

When I showed this DOE to Stirling Trayle, he was all over it...

"The power of DOE compels you!" :p

Fun stuff Stephan. Might be easier to buy a new home with a rectangular room you can measure with REW and then model all these variables. ;)