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A Visit with Bob Carver and His Amazing Line Source Speakers

amirm

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#1
I owned my first Carver product back in 1982 or so. It was a 200 watt receiver with amazing FM tuner and light as a feather due to voltage rail switching that increased its efficiency.

Fast forward some 35 years later and I was finally face to face with Bob Carver organized at an event by our Pacific Northwest Audiophile Society. Bob had brought a complete system for us to listen to and we spent a couple of hours doing exactly that.

I must stay, I was not prepared for Bob's personality. He was totally unassuming, humble and friendly. He wore a ship captain's hat which fit that persona a lot better than an audio engineer/legend. Nice to see no hint of arrogance or kingship.

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The room for the audiophile society is the basement of a local church. It has dropped ceiling and I would say about twice as large as typical audiophile listening room when you include the adjacent spaces. This is my first time in this space so no reference for whether it sounds good or not (to society just moved back here).

Here is the system and space with and without Bob :)

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The system consists of a Mytek DAC driven by a Mac which in turn was streaming Tidal. The output of the Mytek DAC drove a Carver pre-amp which in turn drove them tube amplifiers you see on the floor.

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Most of us where there though to hear the line source speakers though. They were driven through an analog processor that had three controls, one for voices (?) and the other for tonal control.

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As you see the speakers are two-way with line source drivers in front and traditional drivers on each side.

The line source drivers were developed for small bookshelf speakers for one of Bob's earlier companies by a Chinese manufacturer. Here of course a lot more were used.

On top there is another tweeter that is designed to allow the speakers to work better when the ceiling is not right above them (?).

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There was also a narrow sub that was free standing but normally designed to go in between studs in wall.

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The sub has an unusual third driver in between the two larger ones that works in reverse to counter vibrations from the two drivers:

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Listening impressions in follow up post.
 

amirm

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#2
Close up of the amplifiers:

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The amps are unusual in that they have dynamic bias to keep them cool at low power handlings. He said the tubes should last for many years and put his hands on the tubes to show how cool they were running.

He said the amps also used the back EMF from the speakers to pick up characteristics of the room and compensate. Sad to say, neither the theory or the sound in practice showed any evidence of that.
 

amirm

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I asked why Bob had gone back to tubes he said he started with tubes but thought they were dying in 1970s and started to build his Phase Linear amplifiers at high power ratings. But now that tubes are back, he likes to work on them so here we are.

Also, the speaker drivers are run in a way to cancel crosstalk between the two ears. That is, the left and right drivers inside each line source are run through a delay that is proportional to the distance between our ears in sound speed (around 800 milliseconds).
 

amirm

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OK on to listening impressions: https://www.shazam.com/track/413168/peter-gunn#referrer=shz.am


Nice track. Right away I noticed the warmth of the presentation.

Bass level was a bit too much though. But the strangest thing was that the soundstage seemed right at the ceiling! I had never heard such an effect before. It was very unsettling.

Later on Bob explained that he did not like it when line arrays produced soundstage that was too close to the floor (I don't either). So used his wife as a test subject to place the stage at her height. He did this by reducing the level for the lower drivers in the speaker. Alas, to my ears the soundstage was no where at that point. It was way, way up and pretty distracting. This alone would rule out the speakers for me.

I asked if this was adjustable and he said no. Sad as he has all those other controls.
 

amirm

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#6
I just used Shazam to discover The Pink Panther Theme by The Ultimate Mancini Orchestra. https://shz.am/t68718033
A classic demo track:


Focused image was nice but as mentioned, way, way too high. I was in front row, center seat by the way. :p
 

amirm

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I just used Shazam to discover You Bring Out The Savage In Me by Cécile McLorin Salvant. https://shz.am/t83906026
Another classic and favorite:


By now you should know the story: presentation was warm (pleasant) but soundstage stuck at the ceiling.
 

amirm

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I just used Shazam to discover What A Shame by Patricia Barber. https://shz.am/t10843664
The old classic demo track:

Here I noticed something else. In extreme panned sounds, the sound was coming from a narrow slit of the speakers. It had no width.
 

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I just used Shazam to discover Piano Sonata, Op. 57 In F Minor, "Appassionata": I. Allegro Assai by Vladimir Horowitz. https://shz.am/t107804895
(this is not the right version -- see the link above)

By now it become clear to me the focus of these speakers: they consistently sounded grand, warm, pleasant albeit with way too high of a soundstage. It homogenizes music which I tend to not like but it is a pleasant effect if it doesn't bother you.
 

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#12
I just used Shazam to discover Mary Shut The Garden Door by Donald Fagen. https://shz.am/t43799603

Very nice demo track. But boy there are a lot of compression artifacts in the youtube video above!
 

amirm

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#14
I just used Shazam to discover Behind Blue Eyes by The Who. https://shz.am/t251527

I asked them to turn off the sub and I was pleasantly surprised by how much bass there still was and how a lot of the tubbiness had gone away.
 

watchnerd

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Focused image was nice but as mentioned, way, way too high. I was in front row, center seat by the way. :p
Huh....I use full size panels sometimes and don't get that effect.

I'm trying to figure out why a line source would be perceived any differently than a panel in terms of height...
 

amirm

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#17
I just used Shazam to discover Never Going Back Again by Fleetwood Mac. https://shz.am/t226423

Nice line source effect without much drop off in sound level as you approached the speakers.

Walked to the back of the room and the imaging was still too high although not quite as bad as in front row.
 

amirm

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I just used Shazam to discover Copland: Fanfare For The Common Man by Zubin Mehta & Los Angeles Philharmonic. https://shz.am/t55118062
(not the right album)

Dynamic. A bit buzzing of on trumpet. Bob said that he allows a lot of overlap between drivers to the tune of 6 db/octave. He said it gave them depth (?). Not cutting off the resonances of the line drivers may have caused this effect though. But could be in the source too.
 

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