Audio Asylum - Inmate Systems

Bold Eagle's JBL L110's System
IP Address: 71.31.128.90	Last Update: July 02, 2007 at 16:20:54
Amplifier:	Onkyo Integra TX-870 Receiver. 1988-89 vintage. Power is a very conservative 105 W/ch into 8 ohms, 175 W/ch into 4 ohms. Dynamic power is 135/235/315 into 8/4/2 ohms. Plenty of low impedance power down to an honest 2 ohms. Massive power supply with a huge transformer and 20,000 mFd filter caps. Damping Factor of 80 is nearly ideal for the JBL's. Open, airy highs and a clean midrange. Deep, powerful bass. Makes the sound more "live" sounding. Frequency response through the CD Direct input is +/- 0.15 dB from preamp input to power amp output and +/- 0.2 dB with tone controls set to flat. There are pre-out/main-in jacks. Overall, an excellent design. The internal tuner section is used now that I have a better antenna set up.
Preamplifier (or None if Integrated):	Part of the Onkyo TX-870. Preamp output impedance was a moderate 2200 ohms, which is too high, so an emitter follower was added which is designed for a 75 ohm output impedance. So the preamp can drive most anything now. All inputs and outputs are fully buffered and very low capacitance, so there is no chance of components interacting. There is a CD Direct input switch which bypasses the tone controls, effects, and balance and uses its own two sections of the 4 gang volume pot. With the tone controls set to flat one cannot hear if the CD Direct is in use or not. Frequency response as noted above is very flat. The CD Direct circuit has been modified by moving the pickoff point from before the CD input buffer to after the buffer. This makes the input very low capacitance and nearly a pure resistive load for the CD player.
Speakers:	JBL L-110's. The consumer version of the 4313B Control Monitor. 1980 vintage. A 10" three way with a 5" mid and 1" soft dome. Crossover is straight JBL and has impedance compensation (Zobel networks) on all three drivers. The original JBL woofers were lost (a tragedy) and replaced with SEAS 25F-EW woofers with coated paper cones. A perfect sonic replacement with a smoother midrange than the original. 2" longer port to match the SEAS and the cabinet is about 70% filled to creat the Port Assisted Acoustic Suspension design. This is a real alignment, but fairly obscure, although you can find it if you dig around. Original black grill fabric. A great classical music speaker with excellent bass range. Bass is very deep going down to a usable 25 Hz, solid and tight and with excellent articulation and detail. Terrific sense of slam! Mids and highs are natural, subtle, airy, and have a fine sense of depth. Detail is really surprisingly good, as is the sense of depth and the special ability to reproduce hall ambience. Cello and Bass are particularly nice, and vocals sound live. On a good recording it's impossible to tell you are in a small room if you close your eyes. Sound is totally detached from the speakers. JBL's are stereotyped from the L-100's and other very punchy forward speakers. These are a different animal altogether. Cabling is equal length runs of Esoteric 12 gauge with gold plated dual banana plugs on the amp end and giant spades on the other. The speaker's input connectors were replaced with 5 way binding posts.
Sources:
CD Player/DAC:	Rotel RCD-971. IMHO the best available under $1000. Very well matched to the JBL's and Onkyo TX-870 power amp and preamp. Bought as a replacement for an aging and beloved Onkyo DX-220 CDP. The sound is very similar to the Onkyo, but smoother in the high end, and with noticeably better imaging, much better sense of depth, and amazing ambience retrieval. In the latter respect, this player is very, very good. Extremely low output impedance (79 ohms) makes it load and cable insensitive. People who don't like CD ought to hear this model in this system.
Turntable/Phono Stage:	none
Other Source(s):	AM-FM tuner is part of the Onkyo Integra TX-870 receiver. 4 gang equivalent front end. Very sensitive and with very good selectivity. Image rejection is excellent. Large, well regulated power supplies. 4 mode APR automatically selects best combination of settings for cleanest signal. Very unobtrusive hi-blend. Has fine steps of 0.02 MHz for tuning slightly away from a stronger station. Also has a 10 dB input signal attenuator for strong stations. Smooth and clean highs with minimal sibilence and false brightness. A good antenna helps immensely. Sony CDR-W1, dual tray CD player/duplicator. A very nice unit. Also an Onkyo TA-R240 cassette deck. Older, but very nice deck with bias adjust. These two are set up as a CD duplication/tape transfer station.
Other Accessories/Room/Misc.:
Speaker Cables/Interconnects:	Speaker cable is equal length runs of Esoteric Brand 12 gauge ultra fine strand cable to cut effective DCR to 0.1 ohms. Gold plated banana plugs at the amp end, giant gold spades at the speaker end. Both are soldered to the cable to prevent loosening or oxidation. Interconnects for the CD player are DiskWasher "Gold-Ens" 1/2 meter long, and seem to be well made with gold plated connectors, 35 pF capacitance. Chosen for good build quality and balance with the CD. The pre out to main in jacks on the Onkyo TX-870 are connected with the factory jumpers as they seem to work the best. Tara Labs Prism 3 1 meter cable is also used with the Sony CDR-W1 and Onkyo TA-240R.
Other (Power Conditioner, Racks etc.):	A good surge protector to guard against lightning surges on the electronics. Our power is pretty clean here, so only the surge protector is needed. A ferrite clip on is used on the Onkyo TX-870 power cord, just in case.
Tweaks:	Several: 1) Matched runs of fine strand Esoteric Brand 12 gauge with gold plated banana plugs and gold spades soldered on. 2) Very careful speaker placement. 3) SEAS 25F-EW woofers replacing the JBL's. Major effect on the midrange smoothness and deeper and tighter bass. Port lengthened 2" and enclosure 70% filled to match the new woofer. 4) Preamp tone controls and balance control calibrated to find flattest settings. I do this with all my gear to avoid ugly surprises. In this case the bass and treble controls were off a bit, so the flattest settings were marked. 5) CD Direct pickoff point moved to after the CD input buffer amp. Makes the input pure resistive with very low capacitance and cable insensitive. 6) Added emitter follower to preamp output to lower output impedance to 75 ohms. 7) Additional fiberglass added directly behind the woofer to eliminate internal reflections that could radiate out through the port or the woofer cone. Makes the mids cleaner. 8) Revised antenna set up for the receiver eliminated the need for a separate high end tuner. They are now indistinguishable. 9) Dual gold plated banana jacks added to speakers. 10) Crossover has new woofer inductors with lower DCR to help get the bass Q right. 11) Crossover has film and foil caps in all the series locations, but the Zoebels were non-polar electrolytics. These were changed to film caps or non-polar electrolytics bypassed with film caps. Everything else is functionally stock.
Room Size (LxWxH):	15' x 15' x 8'
Room Comments/Treatments:	Left speaker is on the short wall about 26" from the corner and angled to the right about 30 degrees aiming at the right rear corner of the room. Right speaker is 23" down the right side wall angled left about 30 degrees and aimed at the left rear corner. Listening position and components are in the left rear corner in front of double doors. It took a long time to find this setup. Speakers are close to the nearest wall, which they are designed for. Room is moderately well damped. 12" stands, but no spikes or cones. I cannot transmit the bass energy into the floor, as I have downstairs neighbors. Bookshelves on the walls provide very good diffusion. On a mono source, the left and right channels sound identical, so the room interactions are symmetrical. This is really important for imaging, which this system does unusually well.
Music Preferences and Comments:
Music Used (Genre/Selections):	Jazz (Brubeck, Miles Davis, Oscar Peterson, Monk, Lovano, Grover Washington, Ramsey Lewis), Classical(Beethoven, Mozart, Bizet, Sibelius, Ravel, Moussorgsky, Vivaldi, Smetana, de Falla, Borodin, Tchaikovsky, etc), Popular & Folk(Diana Krall, Carly Simon, Joan Baez, Don McLane, Cat Stevens, James Taylor, Creedence Clearwater, Simon and Garfunkel, Steely Dan, Dire Straits, Eagles, Beatles, etc., etc.)
System Goals/Comments:	A long term quest for a highly accurate, natural, and musical reproduction at an optimum cost level. The music has to come through. I also have a desire to understand how this stuff really works despite the folk lore, what "everybody" knows, "expert opinions", BS, ad copy, rave reviews, etc. So I measure everything and run lots of little experiments. I've been playing with this stuff for 50 years, ever since I was 15. This is the best system I've had. The next best was a pair of Double Advents in the same room and the third was in a treated basement rec. room with a large pair of Infinities, full active biamped. Not as accurate and musical as this one. I have about $1400 invested in this system as everything but the CD player was bought used.
System Strengths:	Highly musical and terrific imaging with a profound sense of depth. A very well matched up system. Once the music starts playing you very quickly forget the equipment and begin hearing the performance, the musicianship, the counterpoint of the instruments and parts. Very accurate timbre of instruments and vocals. Massed strings sound breathtaking. Everything sounds at least very good, and better recordings are amazing. The system has been developed around CD's as the source, and they are amazingly good. I have none of the usual complaints about CD's. Ambience retrieval is especially good and along with a very good sense of depth, makes it impossible to tell you are not in the original environment (eyes closed, of course)with the musicians. This system puts you in the room with the musicians, rather than bringing them into your room. The sound is so well detached from the speakers, that I find it hard to listen to the speakers during setup. I keep finding myself listening to the music instead.
System Weaknesses:	Nothing. I live in a condo and wish I could crank it up a little more.
Video/HT System: Separate
TV/Projector:	32" RCA
Processor/Receiver/Amplifiers:	Onkyo Integra TX-870 receiver. This is my second one. See above for details. Excellent sound for the VCR, TV movies and DVD. Very good sound for easy listening, serious listening, dinner music, background, etc.
Speakers (Center, Surrounds, Sub):	Bose AM-5 series II. High WAF. A very good sound with the Onkyo receiver. They are very nice for some serious listening, TV sound, casual listening, dinner music, and background. I kid you not! Proper setup is critically important, though. The Bose supplied 16 gauge is cut to minimum length from sub to satellites and amp to sub. The Bose supplied cable is 16 gauge, but very low inductance. It's good stuff. A lot of work on placement and satellite orientation. Took a loooonnnnnng time to get right. Made a huge difference. I know the Bose stuff has a poor rep with the audiophiles, but don't knock it if you haven't heard these. Most set ups I have heard were terrible, and many are mis-wired with regard to phase. I would rank them in the same ballpark overall as the Vandersteen 1C system driven by NAD electronics. I know that sounds impossible, but trust me, it's true. As I write this, I just came from auditioning the Vandersteens, and they give the same impression. How they'd do side by side I can't say, but the overall impression is the same. Maybe it's the time and phase coherent full range drivers Bose uses above 250 Hz? They didn't work at all well in the den where my JBL's are (and where my Double advents used to live). They seem to need more space to work in, and a greater listener to speaker distance. Since the living room is 16' x 28' it works out fine. Originally bought them for the high WAF and for TV sound and some dinner music, but they turned out to be a very pleasant surprise. But you simply CANNOT just unpack them, hook them up and listen.
Sources (DVD/VCR):	Sony DVP-NS700P DVD/CD/CD-R player. Sounds the same as my Sony CDP-XA1ES CD player, but is less interconnect sensitive. Good video performance as well. Sony VCR.
Other HT Gear:	None. System is stereo only.
Comments on HT System:	Stereo only. TV's speakers are left on for TV sound, VCR, or DVD play to give a center fill, and add some ambience. A poor man's three channel set up. For music CD's only the Bose AM-5's are used.
Other Interests/Hobbies/Occupation:	Retired Engineer, professional background in vibration and acoustics for 12 years of my career, car and racing fan, golf club builder/player, computers, serious photography (now digital), and I have a nice electronics bench for hobby projects and audio ex