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Mr. Widget
11-18-2004, 04:51 PM
For those of you unfamiliar with the Project May program that was begun about a year ago by a suggestion that we, the members of this Forum, build a Lansing speaker for our esteemed Webmaster and Forum Moderator Don McRitchie, please check out this link.

http://www.audioheritage.org/html/projectmay/pmintro.htm

The first complete prototypes of this system are now up and running here in San Francisco. I realize this is short notice, but in the interest of keeping the ball rolling and continuing to move forward during the upcoming holiday season, I will be hosting an audition this Sunday November 21. This audition is open to any interested forum members who are in the San Francisco Bay Area and would like to come by.

The audition will be held Sunday afternoon from 2:00pm. If you would like to be part of this listening session and meet other Lansing fanatics, please send me a PM.


Here is a shot of one prototype in all of it's rough beauty.

Widget

lfh
11-18-2004, 06:31 PM
I've been staring at the picture for like five minutes now...so extraordinarily super-mega-ueber-cool! (Wish I could come on over, but...)

johnaec
11-18-2004, 10:23 PM
Well, I really tried, but I just can't get out of a band rehearsal this Sunday afternoon. :( I definitely want to hear them down the line sometime, though...
Take some pics this weekend, and down a few for me! :cheers:

John

lfh
11-19-2004, 01:07 AM
Well, I really tried, but I just can't get out of a band rehearsal this Sunday afternoon.

That's the downside of playing the most important instrument of them all. ;)

Infredible
11-19-2004, 09:40 AM
I will be there for sure.

Fred.

Real Prober
11-19-2004, 09:22 PM
I'd be there if I have time.. but I will be busy this weekend. Sorry. :banghead:

Zilch
11-21-2004, 06:15 PM
We met new friends,
Drank fine wine,
Heard great music,
Learned new stuff.

The speakers were awesomely good, too....

;)

dancing-dave
11-21-2004, 07:11 PM
Any news of the project making its way to the Tri-State/New England area?

Titanium Dome
11-21-2004, 08:23 PM
Will there be a SoCal/LA audition, perhaps at the Northridge Facility? You must know someone who'll let you in... :yes:

Mr. Widget
11-21-2004, 11:41 PM
It was fun meeting several more Forum members. I wish we had had more time to schedule this audition session so that even more folks could have come by and participated. It was interesting to hear the many comments made during the audition and it great to hear the wide range of music from people's favorite discs. Many were familiar but others were real ear openers.

As for the next stop for this traveling circus, I believe it is heading to Utah for TimG to do additional measurements. I have ordered a Clio loudspeaker measurement system for my own use. I will call the distributor on Monday. It has been on order for a while, if it is again in stock and will be shipped to me soon I will hold onto the Project Mays for a bit longer to do some additional tests here first. If my Clio system is still on back order, I will be packing it up for TimG. After that I am not sure where it will turn up.

For more details and technical descriptions of what has been going on check out the dedicated Project May threads.

Widget

boputnam
11-21-2004, 11:46 PM
First-vs-Final
I hope the resolution is useful, here.

First, a Spectrum comparing the First configuration, vs the Final configuration. Widget has all the relevant notes on the modifications that were made to the three networks, but suffice it to say, every mod he made (under the direction of Giskard) improved the response and sound.

Blue = original, Green = Final. For this display, the spectrum are "matched" such that the Green does not exceed (obscure) any Blue bar - you can see the subtle but audible increased LF response of the Blue that is reduced in the Green.

boputnam
11-21-2004, 11:47 PM
ibid, FFT (Fast Fourier Transform).

Colors:
Pink = First
Green = Final

Here, the spectrum (traces) are normalized at approx. 400 Hz - that is, they are matched there (where there was an audible boost in the Pink), and the Green shows Final. The Green is much more level (flatter) all along the spectrum = good. (ignore the artifacts +18kHz)

boputnam
11-21-2004, 11:48 PM
REMEMBER!!! This is dry - without ANY EQ. No nada, no nothing. Nunca.

Just incredible engineering on Team May's part. May is running full-range, completely passive networks. Wow...

http://audioheritage.csdco.com/vbulletin/images/smilies/thumbup.gif

boputnam
11-21-2004, 11:49 PM
Most measurements (all RTA spectra) were taken with SmaartLIVE generated Pink Noise. However, source material is not relevant in the FFT cases - in those, the source data is compared real-time to the acoustically measured data, incorporating a delay for the input signal so the two signals are in-synch.

http://audioheritage.csdco.com/vbulletin/images/smilies/cool.gif

boputnam
11-21-2004, 11:49 PM
Without their approval, I offer you a shot of the ears - toward the end of our trialing.

From Left -> Right:

Widget, Ms. Gadget, Freddie, Zilch, Speakerdave (seated) and DonC. The shot is taken from the extremely well measured RH tower, looking nearly up the barrel of the Earthworks M30 microphone (directed at the MF - you can see it gets priority...).

Thanks to Widget, whose generous and patient aural and physical donations to May (and pedantically blue-taped markings!!) advanced this phase, measurably. And, as always, kudos to the inimitable Giskard who was longingly on the other end of the phone... http://audioheritage.csdco.com/vbulletin/images/smilies/frown.gif

boputnam
11-21-2004, 11:50 PM
Nice!

johnaec
11-22-2004, 07:05 AM
Great pics, Bo! It didn't even enter my mind you'd be doing a Smaart analysis - 'good move. Do you just use the built-in sound card on the laptop? Does the mic go straight in, or are you using some kind of pre-amp?

I talked to Widget as you guys were winding down. He mentioned the low frequency roll-off - I think a SUB1500 should be swapped in for one of the 1500AL's - 'wonder what that'd sound like? :D

Anyway, 'really wish I could have made it. But at least we did manage to add a couple Carl Perkins tunes at band rehersal... :band:

John

boputnam
11-22-2004, 09:16 AM
Hey, John - you missed some interesting time, for sure.

The data enters the laptop through the USBPre (http://www.usbpre.com/) (also use Search on the Forum - there's some other Threads that refer to it). Most laptops need outboard, two-channel (input) pre-amps to fully function with SmaartLIVE - there are few options on the laptop build that accomodate soundcard selection.

USBPre is really nice, 24-bit, with two XLR-female inputs (each with 15dB switchable pads); outputs are RCA (SmaartLIVE can receive two separate channels of input while generating Pink noise...); etc. Click on "Specifications" on the USBPre site.

At this point, we could follow DonC's suggestion and move the mic succcessively vertically to measure the comb filtering effect(s), but presentation of the results would be messy (at least with my low-level-user-ability on SmaartLIVE). I'm not even sure this is the right tool for that. Maybe Oldmics has some ideas or tips...? Polar plots are next, I'd say...

Ian Mackenzie
11-22-2004, 10:11 AM
No doubt the dispersion in vertical polar axis is going to be a key point in listener location preferences.

Tim should be able to model the relative response lobes in his simulations without us having to resort to tedious measurements.

Ian

boputnam
11-22-2004, 10:56 AM
(text here for ten character limit)


:p

Oldmics
11-22-2004, 09:56 PM
Hey

What the hell is that you-pawwwwww (UPA) doing in the picture.

Center channel ???????

Oldmics


Bo-I will PM you.

Mr. Widget
11-22-2004, 10:15 PM
Well...um...er, yeah. There are two more lurking behind the two Project Mays. They are for my HT. The center one is centered below my screen. You know they are nice, but they sure aren't like those BIG JBLs. :D

Widget

Zilch
11-22-2004, 10:27 PM
We needed SOMETHING to prop the test gear on. It was handy, is all.... :rolleyes:

Donald
11-23-2004, 09:37 PM
I would take a day off work to attend a fest at Northridge.