My SDA SRS 1.2TL Bi-Amp Adventure (Long)
DarqueKnight
Posts: 6,765
Page 7 of the SDA SRS 1.2TL owners manual states:
The SRS is equipped with two sets of inputs to facilitate bi-amplification or bi-wiring .This enables the system to achieve greater dynamic range with lower distortion.
Page 4 of the 1990 SDA SRS brochure states:
For even greater dynamic range and lower distortion, the SRS loudspeakers may be connected for Bi-Amplification using the two sets of inputs provided on each loudspeaker. No electronic crossover is necessary. By permitting different amplifiers to reproduce the high and low frequencies separately, the SRS loudspeakers achieve their greatest sonic potential.
Im certainly interested in having my SRSs achieve their greatest sonic potential! I like my SDA SRS 1.2TLs because they are capable of producing a life-size sound stage, accurate stereo imaging, and clarity that is comparable to what I hear in a live jazz concert.
Reference Equipment Configuration:
Denon DCD-1650AR CD Player (modified with higher grade analog op amps and master clock)
Adcom GFP-750 preamp
Two Adcom GFA-5802 power amplifiers
One 1-meter pair of Monster Z200i RCA interconnect cables (cd/preamp)
Two 1-meter pairs of Monster Z200i RCA interconnect cables (preamp/power amps)
Two 10-foot pairs of Monster Z3 speaker cable with medium gold spade connectors.
Polk Audio SDA SRS 1.2TL Speakers with upgraded crossover components and Cardas CCGR-S binding posts.
The GFP-750 preamp has two sets of RCA output jacks to facilitate bi-amping, therefore no Y-adapters were required.
My listening preferences are well-recorded instrumental and vocal jazz records and CDs.
Reference Recordings (CDs):
1. Time Out, Dave Brubeck Quartet, Track 3-Take Five.
2. Chameleon, Herbie Hancock, Track 1-Chameleon.
3. The Very Best Of George Howard, George Howard, Track 1-Love Will Follow, Track 5-Dianes Blues.
4. Kind Of Blue, Miles Davis, Track 1-So What.
Evaluation Procedure:
Listening notes were made with respect to sound quality, sound stage dimensions, and image placement within the soundstage. Diagrams were drawn of the relative locations of instruments within the soundstage. Four Tiptoes aluminum isolation cones were used under each power amp.
Prior to this experiment in bi-amplification, I tried bi-wiring with the GFA-5802 amp and bi-amping with two GFA-5500 amps. The details of those experiments are detailed Here.
First, I wanted to make sure that I had a reasonably matched pair of GFA-5802 amplifiers. Test tones and musical selections were played through each amplifier and sound level measurements were taken to verify that no obvious differences in gain and sonic characteristics existed. To my ears, there was no audible difference between the two amplifiers.
My evaluation began after an hour of warmup with the amplifiers in a horizontally bi-amped configuration. The speakers are not designed for vertical bi-amping, although I am aware that some SRS owners successfully use this configuration by tying the grounds of the two amplifiers together. Listening notes were made with the system in single amp mode first and then in bi-amped mode. Sketches of the placement of instruments within the soundstage were made in both single mode and bi-amped mode. The average SPL of the music during the listening session was 92 dB. I was seated 17 feet back from the plane of the speakers. The 1.2TLs were spaced 6 feet - 8 inches apart and 11 inches from the rear wall.
Due to the good results I heard with the bi-amped GFA-5500 configuration, I had high expectations for the bi-amped GFA-5802 configuration. Regrettably, those expectations were not realized. Whereas I heard more dynamics, clarity, and fullness of sound with the bi-amped GFA-5500 configuration compared to the single amped GFA-5500 configuration, I heard the opposite with the bi-amped GFA-5802 configuration. The bi-amped GFA-5802 configuration sounded worse in every respect.
The dimensions of the soundstage and the relative positions of instruments within the soundstage remained the same when going from single amped to bi-amped GFA-5802 configuration. I experienced some sonic degradation when I went to a bi-amped GFA-5802 configuration: there was a noticeable loss of sonic detail, dynamics, clarity, and particularly bass articulation and impact. Some examples:
1. Paul Desmonds alto saxophone solo on Take Five has a light airy quality that is noticeably diminished in the bi-amped configuration. The notes of the acoustic bass become less distinct. Dave Brubecks piano notes lose some of their sparkle and take on a slightly glazed over quality.
2. Dianes Blues is a study in contrast and dynamics. The hard slamming bass lines contrast sharply with George Howards soprano saxophone notes swirling and floating above them. In bi-amped mode, the bass loses some of its kick and the saxophone loses some of its sweetness and clarity.
3. On So What, John Coltranes tenor sax and Cannonball Adderlys alto sax lose some clarity. The acoustic bass lines become less articulate and boarderline muddy. The drum kit high hat loses some shimmer and air. There is less of the metallic sound of the wooden drumstick striking the metal cymbals.
Conclusion
Sometimes bi-amping produces very audible improvements (as in the case of the GFA-5500). Sometimes it produces no audible effects at all or it produces audibly inferior results (as in the case of the GFA-5802). When I emailed Adcom customer service about my interest in bi-amping with two GFA-5802s, their reply stated that I would probably notice little, if any, sonic improvement. Their view is that the higher you go up in amplifier power, the less beneficial bi-amping becomes. I am sure the design of the speaker has a lot to do with it also. Theil does not offer a bi-wire/bi-amp option with their loudspeakers because they believe a high quality single amp configuration provides the best and most coherent sonic presentation. John Dunlavy (formerly of Dunlavy Audio Labs) personally told me that, even though DAL offers bi-wire/bi-amp capability with their speakers, they do it for marketing reasons rather than their belief in any sonic benefits. In Dunlavy Audio Labs listening room at their corporate headquarters, none of the speakers were set up in a bi-wire/bi-amp configuration. Mr. Dunlavy said he personally didnt believe in bi-wiring/bi-amping because when you double the amount of cables and double the amount of amplifiers, you are doubling the amount of distortion and other non-linearities that cables and amplifiers introduce into the audio path.
With regard to Polks statement that: For even greater dynamic range and lower distortion, the SRS loudspeakers may be connected for Bi-Amplification using the two sets of inputs provided on each loudspeaker. I found that this was true for one pair of identical 200 watt amplifiers and not true for a pair of the same companys flagship 300 watt 2-channel amplifier. Assuming that the vast majority of audio enthusiasts do not use high-powered amplifiers, Polks advice to bi-amplify the SRS series speakers was useful and appropriate. However, my results lead me to think that I might achieve more audible improvements with moving to a higher powered single amp, like the Bryston 14B-ST (500 watts) rather than bi-amping.
I am interested in learning about the bi-amplification experiences other SRS owners have had with other amplifers, other SRS series speakers, and other bi-amp configurations (vertical vs. horizontal).
The SRS is equipped with two sets of inputs to facilitate bi-amplification or bi-wiring .This enables the system to achieve greater dynamic range with lower distortion.
Page 4 of the 1990 SDA SRS brochure states:
For even greater dynamic range and lower distortion, the SRS loudspeakers may be connected for Bi-Amplification using the two sets of inputs provided on each loudspeaker. No electronic crossover is necessary. By permitting different amplifiers to reproduce the high and low frequencies separately, the SRS loudspeakers achieve their greatest sonic potential.
Im certainly interested in having my SRSs achieve their greatest sonic potential! I like my SDA SRS 1.2TLs because they are capable of producing a life-size sound stage, accurate stereo imaging, and clarity that is comparable to what I hear in a live jazz concert.
Reference Equipment Configuration:
Denon DCD-1650AR CD Player (modified with higher grade analog op amps and master clock)
Adcom GFP-750 preamp
Two Adcom GFA-5802 power amplifiers
One 1-meter pair of Monster Z200i RCA interconnect cables (cd/preamp)
Two 1-meter pairs of Monster Z200i RCA interconnect cables (preamp/power amps)
Two 10-foot pairs of Monster Z3 speaker cable with medium gold spade connectors.
Polk Audio SDA SRS 1.2TL Speakers with upgraded crossover components and Cardas CCGR-S binding posts.
The GFP-750 preamp has two sets of RCA output jacks to facilitate bi-amping, therefore no Y-adapters were required.
My listening preferences are well-recorded instrumental and vocal jazz records and CDs.
Reference Recordings (CDs):
1. Time Out, Dave Brubeck Quartet, Track 3-Take Five.
2. Chameleon, Herbie Hancock, Track 1-Chameleon.
3. The Very Best Of George Howard, George Howard, Track 1-Love Will Follow, Track 5-Dianes Blues.
4. Kind Of Blue, Miles Davis, Track 1-So What.
Evaluation Procedure:
Listening notes were made with respect to sound quality, sound stage dimensions, and image placement within the soundstage. Diagrams were drawn of the relative locations of instruments within the soundstage. Four Tiptoes aluminum isolation cones were used under each power amp.
Prior to this experiment in bi-amplification, I tried bi-wiring with the GFA-5802 amp and bi-amping with two GFA-5500 amps. The details of those experiments are detailed Here.
First, I wanted to make sure that I had a reasonably matched pair of GFA-5802 amplifiers. Test tones and musical selections were played through each amplifier and sound level measurements were taken to verify that no obvious differences in gain and sonic characteristics existed. To my ears, there was no audible difference between the two amplifiers.
My evaluation began after an hour of warmup with the amplifiers in a horizontally bi-amped configuration. The speakers are not designed for vertical bi-amping, although I am aware that some SRS owners successfully use this configuration by tying the grounds of the two amplifiers together. Listening notes were made with the system in single amp mode first and then in bi-amped mode. Sketches of the placement of instruments within the soundstage were made in both single mode and bi-amped mode. The average SPL of the music during the listening session was 92 dB. I was seated 17 feet back from the plane of the speakers. The 1.2TLs were spaced 6 feet - 8 inches apart and 11 inches from the rear wall.
Due to the good results I heard with the bi-amped GFA-5500 configuration, I had high expectations for the bi-amped GFA-5802 configuration. Regrettably, those expectations were not realized. Whereas I heard more dynamics, clarity, and fullness of sound with the bi-amped GFA-5500 configuration compared to the single amped GFA-5500 configuration, I heard the opposite with the bi-amped GFA-5802 configuration. The bi-amped GFA-5802 configuration sounded worse in every respect.
The dimensions of the soundstage and the relative positions of instruments within the soundstage remained the same when going from single amped to bi-amped GFA-5802 configuration. I experienced some sonic degradation when I went to a bi-amped GFA-5802 configuration: there was a noticeable loss of sonic detail, dynamics, clarity, and particularly bass articulation and impact. Some examples:
1. Paul Desmonds alto saxophone solo on Take Five has a light airy quality that is noticeably diminished in the bi-amped configuration. The notes of the acoustic bass become less distinct. Dave Brubecks piano notes lose some of their sparkle and take on a slightly glazed over quality.
2. Dianes Blues is a study in contrast and dynamics. The hard slamming bass lines contrast sharply with George Howards soprano saxophone notes swirling and floating above them. In bi-amped mode, the bass loses some of its kick and the saxophone loses some of its sweetness and clarity.
3. On So What, John Coltranes tenor sax and Cannonball Adderlys alto sax lose some clarity. The acoustic bass lines become less articulate and boarderline muddy. The drum kit high hat loses some shimmer and air. There is less of the metallic sound of the wooden drumstick striking the metal cymbals.
Conclusion
Sometimes bi-amping produces very audible improvements (as in the case of the GFA-5500). Sometimes it produces no audible effects at all or it produces audibly inferior results (as in the case of the GFA-5802). When I emailed Adcom customer service about my interest in bi-amping with two GFA-5802s, their reply stated that I would probably notice little, if any, sonic improvement. Their view is that the higher you go up in amplifier power, the less beneficial bi-amping becomes. I am sure the design of the speaker has a lot to do with it also. Theil does not offer a bi-wire/bi-amp option with their loudspeakers because they believe a high quality single amp configuration provides the best and most coherent sonic presentation. John Dunlavy (formerly of Dunlavy Audio Labs) personally told me that, even though DAL offers bi-wire/bi-amp capability with their speakers, they do it for marketing reasons rather than their belief in any sonic benefits. In Dunlavy Audio Labs listening room at their corporate headquarters, none of the speakers were set up in a bi-wire/bi-amp configuration. Mr. Dunlavy said he personally didnt believe in bi-wiring/bi-amping because when you double the amount of cables and double the amount of amplifiers, you are doubling the amount of distortion and other non-linearities that cables and amplifiers introduce into the audio path.
With regard to Polks statement that: For even greater dynamic range and lower distortion, the SRS loudspeakers may be connected for Bi-Amplification using the two sets of inputs provided on each loudspeaker. I found that this was true for one pair of identical 200 watt amplifiers and not true for a pair of the same companys flagship 300 watt 2-channel amplifier. Assuming that the vast majority of audio enthusiasts do not use high-powered amplifiers, Polks advice to bi-amplify the SRS series speakers was useful and appropriate. However, my results lead me to think that I might achieve more audible improvements with moving to a higher powered single amp, like the Bryston 14B-ST (500 watts) rather than bi-amping.
I am interested in learning about the bi-amplification experiences other SRS owners have had with other amplifers, other SRS series speakers, and other bi-amp configurations (vertical vs. horizontal).
Proud and loyal citizen of the Digital Domain and Solid State Country!
Comments
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Very nice bi-amp review and comments. More reviews and demos should take on a more formal look and procedure, like yours. Great thread to add into the SDA pile.
CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint. -
Wonder if anyone using Mcintosh MC-1000 mono blocks to mate with them?
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Congratulations! You've refreshed a 16 year old post! Where's his badge guys...Gustard X26 Pro DAC
Belles 21A Pre modded with Mundorf Supreme caps
B&K M200 Sonata monoblocks refreshed and upgraded
Polk SDA 1C's modded / 1000Va Dreadnaught
Wireworld Silver Eclipse IC's and speaker cables
Harman Kardon T65C w/Grado Gold. (Don't laugh. It sounds great!)
There is about a 5% genetic difference between apes and men …but that difference is the difference between throwing your own poo when you are annoyed …and Einstein, Shakespeare and Miss January. by Dr. Sardonicus -
No kidding, I was thinking the same thing yesterday...Remember, when you're running from something, you're running to something...-me
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I really would like your help with this situation I have a set of the SDA SRS 1.2 TL bi mplification and I have the nakamichi pa7 200 Watts X2 as well as the ca 7a for the highs also I have the dragon cassette recorder and the ST-7 AM FM receiver also the CDC-3A CD 6 disc changer and the Yamaha I was thinking of letting go of the one of a kind unit but I know that everything goes together so splitting it up would be doing a disservice to the SDA signature series and also would be doing a disservice to anyone trying to get their hands on it obviously I realize it would be very hard to find somebody that would want to drop all that but being that it's in mint condition and only my grandfather used it very
classy like it has not been torn apart stressing it all out to Max decibels also I do realize that the last post was in 2019 but you guys really taught me a lot by reading the forum and explaining how they actually work also have all the proper wiring and remote controls it's just not wired right now it's been put away because I just didn't have the real estate to give up in my pool house for the sound as I have all Bose set up in there indoor and outdoor speakers there is obviously no comparison but I have them scattered around outside as well so it makes sense just to have it like that and these speakers are so big I'd almost have to remove my refrigerator and put the speaker and its place. LoL so thank you anybody
that can get back to me and let me know what you would do with this exceptional speakers and components all together like a happy family on Christmas having all the right clothes on for the family picture because as I'm reading some of these forms and people looking for this and that they're using all different types of things but this is the way it was put together so I want to know if it should all go together to one special person at some point I just want everybody's opinion on what they would do thank you very much and I
Thank you very much and I enjoy learning from you guys!!!!!! -
HOLY RUN ON SENTENCE BATMAN !!!
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Hahaha true I apologize about that I'm here I am talking into my phone amd my daughter is using me as a jungle gym and it's very hard to concentrate and reread what I wrote but I was just trying to get somebody's opinion or a few of you guys's opinion and also if you didn't already know they're all nakamichi except for that only one Yamaha dsp-1 where's Coco thank you and I appreciate any input that you have
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Congratulations. That's got to be a world record for a single sentence.
Put your daughter back in her pen and ask a simple question because I'm not sure where you are going with all that.Gustard X26 Pro DAC
Belles 21A Pre modded with Mundorf Supreme caps
B&K M200 Sonata monoblocks refreshed and upgraded
Polk SDA 1C's modded / 1000Va Dreadnaught
Wireworld Silver Eclipse IC's and speaker cables
Harman Kardon T65C w/Grado Gold. (Don't laugh. It sounds great!)
There is about a 5% genetic difference between apes and men …but that difference is the difference between throwing your own poo when you are annoyed …and Einstein, Shakespeare and Miss January. by Dr. Sardonicus
