X-over Break In Period

[tysontom]

FYI, the specific setting for the AR-3 LvR demo was mid and treble controls to full and preamp treble at +3dB. AR provided customers who wanted truly "flat" response with a similar recommendation for the AR-3a and AR-5 (they said "increase slightly" for treble, probably because the average customer at the time wouldn't have known how to get +3dB on an amplifier not calibrated that way).

genek,

Where did you get this information? I believe the preamp treble control on the PAS 2 (used in the LvR concerts) was varied according to the venue in which the Quartet was playing, not set at one specific setting. For the guitar concerts, the preamp treble control was sometimes reduced below flat -- again depending on the concert-hall location. Each LvR concert required that a person be seated in the front row to carefully listen for the balance between the instruments and the speakers, thus requiring final adjustments to make the changeovers undetectable.

--Tom Tyson

[genek]

It's buried in the forums somewhere. IIRC, specifically it was the setting used for the Carnegie Hall chamber quartet demo (Carnegie Hall is the musical center of the universe, isn't it?), and it sticks in my memory because I was fortunate enough to have been there, although at the time I was a kid accompanying my audiophile uncle and had not the faintest idea that one day we'd all be here. If I had, I probably would have paid more attention instead of thinking mostly about how soon it would be done so we could go for pizza.

[Rlowe]

genek,

Where did you get this information? I believe the preamp treble control on the PAS 2 (used in the LvR concerts) was varied according to the venue in which the Quartet was playing, not set at one specific setting. For the guitar concerts, the preamp treble control was sometimes reduced below flat -- again depending on the concert-hall location. Each LvR concert required that a person be seated in the front row to carefully listen for the balance between the instruments and the speakers, thus requiring final adjustments to make the changeovers undetectable.

--Tom Tyson

Hello Tom,

The following notes are from the May 1976 B.A.S. meeting.

" The main attraction of this month's meeting was

a live-versus-recorded demonstration staged

especially for the BAS by Acoustic Research." by Victor Campos

The article starts on Page 18 of the PDF of the following;

http://www.bostonaudiosociety.org/pdf/bass/BASS-05-09-7706.pdf

A list of Early B.A.S. meetings is shown at the bottom of the following;

http://www.bostonaudiosociety.org/bas_speaker.htm

R

[Carlspeak]

Thanks R for the link! This is the most detail I've read here at CSP regarding LVR sessions - a much discussed subject here from time to time.

The document should be put in the library. Sometimes links tend to dissapear over time.

[Steve F]

Hello Tom,

The following notes are from the May 1976 B.A.S. meeting.

" The main attraction of this month's meeting was

a live-versus-recorded demonstration staged

especially for the BAS by Acoustic Research." by Victor Campos

The article starts on Page 18 of the PDF of the following;

http://www.bostonaud...-05-09-7706.pdf

A list of Early B.A.S. meetings is shown at the bottom of the following;

http://www.bostonaud...bas_speaker.htm

R

This, of course, is the 1976-77 Neil Grover jazz drummer LvR demos with AR-10 Pi's, not the early 1960's LvR with the AR-3's. The 1960's demos are the ones that Gene K is referring to, and those are the more famous ones.

I have written extensively in these pages about the Grover sessions, since I attended that BAS meeting and I am also a jazz drummer, so the 76-77 demo was of particular interest to me from several angles.

However, the Grover sessions never received the publicity or notoriety of the FAQ sessions with the AR-3's--perhaps because hi fidelity was more of a novelty in the early 60's or perhaps because the earlier sessions were better publicized events.

BTW, I have always been of the opinion that the Grover drumset sessions were a far higher bar to clear--much "tougher"--than the FAQ sessions, in terms of SPL demands, LF demands, and HF 'sparkle' demands. Much tougher. And I think that the 10 Pi's accomplishment was nothing less than astonishing.

Steve F.

[genek]

This, of course, is the 1976-77 Neil Grover jazz drummer LvR demos with AR-10 Pi's, not the early 1960's LvR with the AR-3's. The 1960's demos are the ones that Gene K is referring to, and those are the more famous ones.

My memory is not what it used to be, especially about things that happened when I was in the eighth grade.

As it happens, I was also lucky enough to catch the last 10-15 mins of the 10pi demo (from all the way in the back of the room because of my late arrival), and I never knew the details of either demo until I read them here in the forums, so it's possible I confused the two. Whichever demo turns up in a forum search would be the one I was attempting to refer to.

[Steve F]

My memory is not what it used to be, especially about things that happened when I was in the eighth grade.

As it happens, I was also lucky enough to catch the last 10-15 mins of the 10pi demo (from all the way in the back of the room because of my late arrival), and I never knew the details of either demo until I read them here in the forums, so it's possible I confused the two. Whichever demo turns up in a forum search would be the one I was attempting to refer to.

The 76-77 Grover demos did not use Dynaco electronics, so any reference to Dyna pre-amp tone control settings would most likely be the early-60's FAQ LvR sessions. Both demos have been written about here in the Forum, so you need to know which is which before referencing the Dynaco tone settings.

The source of AR recommending that the treble control (on an AR amplifier) be advanced slightly for flattest response comes from the AR-3a Technical Data Sheet from around 1970-ish, which was different from either their full-line brochure or their individual driver FR sheets.

Steve F.

[genek]

The 76-77 Grover demos did not use Dynaco electronics, so any reference to Dyna pre-amp tone control settings would most likely be the early-60's FAQ LvR sessions. Both demos have been written about here in the Forum, so you need to know which is which before referencing the Dynaco tone settings.

The source of AR recommending that the treble control (on an AR amplifier) be advanced slightly for flattest response comes from the AR-3a Technical Data Sheet from around 1970-ish, which was different from either their full-line brochure or their individual driver FR sheets.

Steve F.

The BAS article refers to PAT-5 preamps being used for the 10pi demos.

Do you recall offhand which demos was the ones where the the power amps had to be scrapped after each show? I'm pretty sure it was the CH demo, so maybe I had it right after all. Forum search doesn't seem to work well on "LvR" (not enough letters) or "live vs recorded" (no results prior to 2009 and I'm pretty sure the topic in question preceded that).

[ironlake]

There is a definate break in to a cone speaker. I am big into model trains and now we have computer controled and wireless operation etc. Anyway when we first get a new locomotive (o scale with most having 2 inch speakers) and as they run you will find yourself turning the volume down as the speakers get more time on them. I have even used a radio shack vu meter to verify that my ear is playing tricks on me. Yes the volume did go up and in some of the larger engines which can have a larger speaker in increased from 60 db to 90 db on a particlular steam engine whistle.

The interesting thing is the smaller scales like HO and even N are getting sound and to get volume out of those tiny speakers tuned acoustic suspension systems are becoming the norm.