keith@uunet.UU.NET (Keith McIntyre) (12/26/90)
This is a marvelous and essentially free improvement for your stereo system.
Please read on even if you don't own the same components that are mentioned
in this posting. My system has a Threshold 400A power amp that has been
upgraded to Stasis technology. In the course of listening to my new Martin
Logan Sequel II speakers, I found that if the power amp was left on and
allowed to warm up, the sound improved noticeably.
Finally I called Threshold and found out that this is indeed the case and
got more exact figures from them on the warm up periods required. There are
at least three warm up periods for a Threshold Stasis amp. I include my own
observations for the curious.
Initial warm up: Threshold's time period: 45 minutes - my estimate: 1 hour
Prolonged warm up: Threshold's time period: 2 hours - my estimate: 2 to 3 hours
Extended warm up: Threshold's time period: 10 hours - my estimate: 12 hours
What are the differences in sound? Imaging is the easiest to describe. Prior
to 45 minutes the sound stage is very small left to right, front to back and
vertically as well. After the 45 minute warm up, the stereo will begin to
image instruments and voices beyond the right hand side of the right speaker
and beyond the left hand side of the left speaker. Front to back imaging or
depth becomes a little better.
After two hours about half of my recordings begin to image out past the
outside edges of the speakers. Vertical imaging starts showing up on some
recordings as well. Depth becomes pronounced, going back several feet even on
many pop recordings.
The extended warm-up of 10 hours can reasonably be accomplished only by never
turning the power amp off - which is in fact Threshold's actual recommenation.
Leave the amp on all the time, it causes less stress in the electronics and
gives the best sound. The result is that imaging goes out past the outside
edges of the speakers on almost all the recordings I have whether they are
pop, jazz, classical or even Christmas music. This is rock solid imaging,
not fuzzy or vague sound placement. Depth is astounding on even pop
recordings. It easily goes back 7 feet or more at a minimum. Vertical imaging
suddenly is evident on recordings that never gave any hint of up and down
sound source placement. Transparency and midrange detail are also enhanced
dramatically. Even bass response improved.
Once the amp was warmed up, I quickly found out that my CD player also
benefitted from a warm up period. The "glassy" or "hard" sound many people
associate with CD players disappears after several hours of warm up. What is
left is a clear, clean, "analytical" type of sound.
Audiophiles love to A/B stereo components. Due to the warm up times involved,
many of us have probably been listening to cold electronics that overwhelm the
differences in components that we have been evaluating. Especially in the area
of speaker wire, component interconnect cables, and other extraneous items.
I would say that any evaluations done with my system on a cold power amp are
practically useless.
Happy listening to everyone!
-Keith McIntyrechowkwan@priam.usc.edu (Raymond Chowkwanyun) (12/28/90)
In article <8550@uwm.edu> ccicpg!keith@uunet.UU.NET (Keith McIntyre) writes: > > >Leave the amp on all the time, it causes less stress in the electronics and >gives the best sound. The result is that imaging goes out past the outside >edges of the speakers on almost all the recordings I have whether they are >pop, jazz, classical or even Christmas music. This is rock solid imaging, >not fuzzy or vague sound placement. Depth is astounding on even pop >recordings. It easily goes back 7 feet or more at a minimum. Vertical imaging >suddenly is evident on recordings that never gave any hint of up and down >sound source placement. Transparency and midrange detail are also enhanced >dramatically. Even bass response improved. > > -Keith McIntyre Has anyone ever experienced a soundstage that extends past the physical side walls of the listening room? Keith doesn't say how far his speakers are from the back wall, but I assume there's a good chance it's less than the 7 feet he experiences. I've also heard music seeming to emanate from beyond the back wall, but the side walls? I've never heard a soundstage go beyond the side walls. -- ray
mha72@leah.albany.edu (12/31/90)
In article <8586@uwm.edu> chowkwan@priam.usc.edu (Raymond Chowkwanyun) writes: > >Has anyone ever experienced a soundstage that extends past the physical >side walls of the listening room? Keith doesn't say how far his speakers >are from the back wall, but I assume there's a good chance it's less than >the 7 feet he experiences. I've also heard music seeming to emanate from >beyond the back wall, but the side walls? I've never heard a soundstage >go beyond the side walls. > >-- ray I have, especially since I placed my MGIIIa's so that the ribbon tweeter is to the outer side of each speaker (that is nearer to the side wall). Placement became more critical than before, and I spent some hours experimenting with distances between the speakers and the walls, and especially the toe-in angle; (to make the speakers disappear, I had to increase the angle from about 5 degrees to about 10 for perfect centerfill). And it was worth it! Overall result: a wider soundstage, and a more open sound in general. With records that have it, the soundstage can extend to twice the width of the distance between the speakers' outer edges, which is well beyond the side walls! For example, most of Airto's records have these wonderful percussion sounds (bells, etc) seemingly coming from the neighbor's house. Happy listenings! Marios
bill@uunet.UU.NET (Bill Vermillion) (12/31/90)
In article <8586@uwm.edu> chowkwan@priam.usc.edu (Raymond Chowkwanyun) writes: >Has anyone ever experienced a soundstage that extends past the physical >side walls of the listening room? Keith doesn't say how far his speakers >are from the back wall, but I assume there's a good chance it's less than >the 7 feet he experiences. I've also heard music seeming to emanate from >beyond the back wall, but the side walls? I've never heard a soundstage >go beyond the side walls. My very first stereo speakers gave me sounds that came from beyond the sidewalls. But I really dont recall how good the soundstage itself was. This was in 1959. A speaker system built by University, TMS-2, called the "Tri-Mensional Sound" system. It had a dual voice coil woofer, one for each channel (and you REALLY knew when the channels were out of phase). Then there were two mid-range 8" units, and two horns. The woofer came directly out the back. The front of the cabinet was solid, and you swung a covering from the front out to make to panels that extened out from the cabinet. (attempt at ascii drawing here) --------------------------------------------- back wall ^ woofer -------\ /--------- | | Tweet & mid range -> > < ------|-----------------|------- ^doors All the sound (ALL) was reflected. This was before BOSE, and about 1.5 years after the introduction of the stereo LP. You had a choice of about 3 cartridges then. The EV ceramic which was released simulataneously with the first 6 disks on Audio Fidelity. The Shure M3-D (which I got) at $45 in 1958 money (VWs were about $1200 new then). And a Fairchild cartridge that was more money. The mono LP's were better then in terms of frequency response, as there were cutter resonances with many cutting heads so the high-frequency range was limited to about 7 or 8kHz, while the monos were touted to hit 20kHz. It was strange to have music coming "through" the wall. You ears told you the music was coming form the other side (at a distance the same amount as the speakers were from the wall). Not bad for it's day. I remember how the stereo LPs were in one SMALL section while the rest of the store was filled with MONO LPS. To put it in perspective, imagine yourself in a music store 4 of 5 years ago, with thousands of LPs and about 200 CDs. Same difference. But is was STEREO - and the sound MOVED! WOW! RCA had a whole series that feature "moving" sound. They did this to show why you NEEDED two speakers, and two amplifiers. Some of the early stereo releases were pretty bad. However, I still have my copy of "Bob and Ray Throw A Stereo Spectacular" (I thinks that the title) and it really is amazing. Holds up pretty well 30 years later. bill -- Bill Vermillion - UUCP: uunet!tarpit!bilver!bill : bill@bilver.UUCP
keith@uunet.UU.NET (Keith McIntyre) (01/03/91)
>>The result is that imaging goes out past the outside >>edges of the speakers on almost all the recordings I have whether they are >>pop, jazz, classical or even Christmas music. This is rock solid imaging, >>not fuzzy or vague sound placement. Depth is astounding on even pop >>recordings. It easily goes back 7 feet or more at a minimum. Vertical imaging >>suddenly is evident on recordings that never gave any hint of up and down >>sound source placement. Transparency and midrange detail are also enhanced >>dramatically. Even bass response improved. >> > >> -Keith McIntyre > > Has anyone ever experienced a soundstage that extends past the physical > side walls of the listening room? Keith doesn't say how far his speakers > are from the back wall, but I assume there's a good chance it's less than > the 7 feet he experiences. I've also heard music seeming to emanate from > beyond the back wall, but the side walls? I've never heard a soundstage > go beyond the side walls. > > -- ray The extremes that I have heard are as follows: Vertical imaging goes up through the ceiling in my listening room and into the attic about 3 feet. My ceiling is a typcial flat 8 foot ceiling. This occurs on the Chesky Jazz Sampler and Test CD using the UP track. Depth imaging goes back 30 feet or more on many of my classical recordings. The speakers are placed 3 feet from the back wall. Lateral imaging goes out past the outside edges of my speakers by 7 or 8 feet on a few CDs. My speakers are placed 2.5 feet from the sidewalls of the room. Good recordings for this are "Yellowstone" by Mannheim Steamroller track 3 (listen to where the birds are located), the venerable Dark Side of the Moon by Pink Floyd (standard CD, not even the audiophile versions are required) tracks 2 and 3 especially the clock chimes, the footsteps and the laughing voices. In talking to Martin Logan about this, I found out that this is better than average imaging, probably due to the decent listening room size, shape and acoustics that I have. Believe me, it adds a great deal to the listening enjoyment of my system. -Keith McIntyre
jhess@orion.oac.uci.edu (James Hess) (01/04/91)
In article <8550@uwm.edu> ccicpg!keith@uunet.UU.NET (Keith McIntyre) writes: > > >This is a marvelous and essentially free improvement for your stereo system. >I found that if the power amp was left on and >allowed to warm up, the sound improved noticeably. > >What are the differences in sound? Imaging is the easiest to describe. Prior >to 45 minutes the sound stage is very small left to right, front to back and >vertically as well. After the 45 minute warm up, the stereo will begin to >image instruments and voices beyond the right hand side of the right speaker >and beyond the left hand side of the left speaker. Front to back imaging or >depth becomes a little better. > Hmmmm... It's well known that phase and frequency response differences between two channels will produce an illusion of stereo separation. (Used in devices from Carver's sonic holography processors to those stereo enhancers on cheap boom boxes.) Is it possible this apparent improvement is nothing more than the results of thermally-induced drift in component values changing the transfer functions of the circuts? In search of sonic utopia... J. Hess