What is stereo?
There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakers are used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.
H.H. Scott '59
A single unit, four-channel preamplifier with unique Quadralizer for the creation of a living presence sound field in the home.
Quadraphonic stereo is the ultimate in sound realism, and with Pioneer's Model QC-800,a quadraphonic power amp (or two stereo amplifiers) and four speakers you can enjoy this sound brilliance today in your own home. This well-made, highly-advanced unit is unusually versatile. It provides a choice from any existing two-channel stereo source (tape,disc of FM), as well as discrete four-channel stereo, the most genuine and thrilling four-channel sound. And it can also be used as a conventional two-channel stereo pre-amplifier if you intend to wait until adding another pair of speakers to your existing stereo set. The QC-800 is a perfect match to Pioneer's Quadraphonic Power Amplifier (Model QM-800). And it's your most versatile introduction to the grandeur of four-channel stereo, a solid investment it the sound of the future that Pioneer has perfected today.
Your Own Acoustical Field
The exclusive Pioneer Quadralizer contained within the QC-800 creates an all-encompassing four-channel sound field in your home, giving you the same, full, life-like sansation of being in an acoustically perfect concert hall.
Choose Your Four-Channel System
The Quadralizer creates four-channel sound from any existing two-channel stereo source - either tape, disc or FM. And the QC-800 gives you a choice of three totally different four-channel effects.
Discrete Four-Channel Stereo
This is both the most authentic in terms of sound quality, and the most expensive since it requires a four-channel tape deck and special four-channel tapes. The sound is reproduced at a very high degree of fidelity, since the tape deck reproduces sound recorded on each of four separate tracks.
Matrix-Type Four-Channel Stereo
The "matrix" system of four-channel sound is one of the quadralizing effect systems in the QC-800. This systems creates a room-enveloping sound field, when signals from a two-channel program source are fed through a unique matrix circuitry contained within the preamplifier. These signals are analyzed and divided into four different signals which are then fed to four loudspeakers systems for sound reproduction. the matrix system is highly suitable for the reproduction of popular music or small combo group performances.
Phase Shift Four-Channel Stereo
The "phase shift" system of four-channel sound is another of the quadralizing effect systems in the QC-800. With this system, the conventional left and right stereophonic channels are reproduced from the two loudspeakers systems situated in front of the listener. But added to this sound is a phase-shifted 'wall of soud", or concert hall effect which emanates from the pair of loudspeakers placed behind the listener. The result is the rich depth of a live performance a slight enveloping echo effect through the two rear speakers, a thrilling musical experience. The Pioneer phase shift system is especially effective in the reproduction of classical or operatic music.
High Stability Head Amplifier
The head amplifier section of the QC-800 incorporates a 3-stage direct-coupling negative feedback circuitutilizing low-noise silicon transistors and emitter-to-emitter feedback. These features result in accurate equalizing characteristics with a wide dynamic range and stable performance.
Switch-Type Tone Controls
The tone control amplifier is a directly coupled three-stage design with a low-noise FET in its first stage. Its high, stable input impedance assures precise tone control at any setting without affecting the head amplifier. The tone controls are true switch types which regulate negative feedback. Each switching step has an effect of +/- 3 dB. Additionally, separate controls are provided for front and rear channels, permitting total control over the total tonal quality.
Versatile Inputs And Auxiliary Controls
Inputs of the QC-800 accept two turntables, two tape decks, a tuner and a choice of two other sound sources. There are separate headphone jacks for monitoring both front and rear channels. Controls include an output on/off switch, a -20 dB muting switch, high and low filters and a tape monitor switch. Versatility of the unit is practically unlimited.
Channel Level Controls
Each of the four channels is equipped with a level control, which permits total control over the sound field intensity even when different speaker types are used for front and rear listening.
Because the QC-800 has a pair of tape deck inputs, tape-to-tape duplicating may be accomplished with ease. Normal two-channel tape-to-tape duplicating is also possible as if four-channel tape-to-tape duplicating.
Output Voltage/Impedance: Output 1,2; 4V/less than 5 Ω (2 ch)
Harmonic Distortion: less than 0,05% (2V output)
Frequency Response: 10 to 70,000 Hz ±1 dB
Phono 1, 2: 4 mV/50 kΩ (2 ch)
Tuner: 250 mV/180 kΩ (4 ch)
Aux 1,2: 250 mV/180 kΩ (4 ch)
Tape Monitor 1, 2: 250 mV/200 kΩ 94 ch)
Recording Output: Tape Rec 1, 2 (pin jack); 250mV (4 ch)
Bass Control: -9 dB, +12 dB at 100 Hz (3 dB step)
Treble Control: -12 dB, +9 dB at 10 kHz (3 dB step)
Low Filter: -8 dB/50 Hz
High Filter: -8 dB/10 kHz
Equalization Curve: Phono RIAA STD
Muting: -20 dB
Hum amd Noise (IHF):
Phono : More than 89 dB
Tuner, Aux : More than 100 dB
Channel Separation (1 kHz):
Phono : More than 50 dB
Tuner, Aux : More than 50 dB
Phones: For (ch 1, ch 3) and (ch 2, ch 4)
Transistors : 32
FET (s) : 4
Diodes : 3
Power Requirements: 110, 120, 130, 220, 240 V (switchable) 50/60 Hz
Power Consumption: 5 watts (max.)
Dimensions (W x H x D): 430 x 145 x 337 mm (16-15/16 x 5-11/16 x 13-1/4 inches)
Weight: 7,6 kg (16 lb 12 oz)
The Pioneer Quadraphonic Power Amplifier, model QM-800 is designed to serve in a 4-channel stereo installation, together with a 4-channel preamplifier, 4 speaker systems and one or several program sources. Engineered for highest sound fidelity, it will open up a whole new world of "environmental sound."
DIRECT COUPLING OF ALL STAGES
Direct coupling of all amplifier stages greatly improves phase characteristics and permits an extremely wide frequency response down to near-DC. A load-regulated power supply unit is employed, and output power is higher than will ever be required.
LEVEL METERS FOR ALL FOUR CHANNELS
To obtain optimum sound balance in a 4-channel system, four separate level meters are provided. Moreover, the meters sensitivity can be adjusted in three stages (0, -10 and -20 dB) to permit accurate readings at all volume levels.
ADJUSTABLE lNPUT SENSITIVITY
As the power amplifier's input sensitivity can be adjusted in 6dB steps (at 0.5, 1 and 2 volts), it is easy to match with any preamplifier.
SPECIAL HIGH-RANGE SPEAKER OUTPUTS
ln addition to the four normal, full-range speaker terminals, a set of high-range speaker outputs are provided. The QM-800 can be used as an exclusive high-range amplifier in a multi-amplifier installation.
PERFECT PROTECTION OF OUTPUT STAGE TRANSISTORS AND SPEAKERS
The output transistors are protected from damage (in the case of overload or short-circuits in the speaker leads) by a dual system of relay and DC drift voltage detector circuits. The latter also guard against possible speaker damage by DC current.
UNIOUE PIONEER EXTERIOR DESIGN
The front panel is attractive as well as logically laid out. With its natural wooden cabinet, the QM-800 matches other Pioneer hi-f i components perfectly.
Even if the power switch of the QM-800 is turned on, the speaker system will not operate for the first 5 to 8 seconds. This is because the QM-800 is provided with a circuit which protects transistor, speakers, etc. from possible damage due mainly to unexpected trouble.
If any of the speaker systems stops operating during a performance, or if mechanical noise (click, click, . . .) of the relays is heard continuously, a short-circuit in the speaker leads may be responsible. Turn off the power and check all speaker connections. Since the protector circuit is very sensitive, it may be activated if the power switch of the preamplifier combined with the QM-800 is turned on and off separately. It is therefore advisable to obtain AC power for the QM-800 from a switchable AC outlet of the preamplifier, as this guarantees simultaneous on-off switching of both units.
POWER AMPLIFIER SECTION
Music Power Output (lHF):
280 Watts per channel at 4 Ω;
200 Watts per channel at 8 Ω
Continuous Power Output (2 channels driven):
42W + 42W / 42W + 42W at 4 Ω;
35W + 35W /3 5W + 35W at 8 Ω
Continuous Power Output (4 channels driven):
32 W x 4 at 4 Ω;
25 W x 4 at 8 Ω
Power Output in the range of 2OHz to 20kHz (2 channels driven):
32W + 32W / 32W + 32W (8 Ω, THD Less than 0.5%)
Harmonic Distortion: Less than 0.5% (Continuous power output)
lntermodulation Distortion: Less than 0.5% (Continuous power output)
Power Bandwidth (lHF):
5 Hz to 50 kHz (8Ω, 2 channels driven, THD Less than 0.5%)
10 Hz to 50 kHz (8Ω, 4 channels driven, THD Less than 0.5%)
Frequency Response: 5 Hz to 80 kHz, ±1dB
lnput Sensitivity/lmpedance (1kHz, Continuous Power output)
0,5 V/70 kΩ
1,0 V/110 kΩ
2,0 V/170 kΩ
Speakers: 4 to 16 Ω (FRONT, REAR, HIGH RANGE)
Damping Factor: 70 (8 Ω, 1kHz)
Hum and Noise (IHF): More than 90 dB
Level Meters: 0 dB = 35 W/8 Ω, (Sensirivity selector 0dB, -10d8 and -20d8)
Transistors : 39
Diodes : 37
110V, 120V, 130V, 220V and 240V (Switchable) 50/60Hz
Power Consumption: 400 W (Max)
Dimensions (W x H x D): 430 X 145 X 337 mm (16-15/16 x 5-11/16 x 13-1/4 inch)
Without package: 11,5 kg (26 lb)
With package: 13,5 kg (30 lb)
Stereo Receiver Features
Programme sensor so that 5 stations on both FM and LW can be preprogrammed. Using the pre-set markers, and the programme buttons, any of your favourite stations can be pre-set. When the programme sensor position is selected any pre-set station on FM or LW can be picked up as you move the tuning indicator
25 watts per channel at 8 ohms into 20 Hz - 20 kHz
4 wavebands; Fm, MW, SW,LW
Loudness switch for improved sound at low listening levels
Separate controls for bass and treble
Automatic muting in stereo mode
FM and LW programme sensor indicators
Programme sensor indicator
Stereo indicator light
Function indicators for tape,phono and tuner
Separate signal strength and centre tuning meters
Audio Amplifier Section
Power Output Continuous RMS
Less than 0,5% THD, both channel driven simultaneously:
25 W + 25 W (8 Ω) at 20 - 20,000 Hz
27 W + 27 W (8 Ω) at 1 kHz
According to DIN 45500
25 W + 25 W (8 Ω)
25 W + 25 W (4 Ω, less than 0,7% THD)
Dynamic Power Output: IHF constant power supply method 90 W (8 Ω)
Power Bandwidth: 10 - 40,000 Hz, IHF
Damping Factor: 20 at 1kHz (8 Ω)
Total Harmonic Distortion:
Less than 0,5% at rated output (8 Ω)
Less than 0,7% at rated output (4 Ω)
Less than 0,2% at 1W output (8 Ω)
Less than 0,3% at 1W output (4 Ω)
IM Distortion (60 Hz : 7 kHz = 4 :1):
Less than 0,5% at rated output
Less than 0,2% at 1W output
Residual Noise: Less than 0,08 μW (8 Ω)
Phono: RIAA equalization curve ±1 dB
Tape: 10 -50,000 Hz +1 dB, -3 dB
Inputs Sensitivity/impedance (¹):
Phono: 2,5 mV(-50 dB)/50 kΩ, 70 dB S/N
Tape: 150 mV (-15,5 dB)/100 kΩ, 90 dB S/N
Outputs (with rated input):
Rec Out: 150 mV (-15,5 dB)/ 10 kΩ
Headphones: Accepts all low or high impedance headphones
Speaker: From 4Ω to 16Ω speakers are suitable
Bass: ±8 dB at 100 Hz
Treble: ±8 dB at 10 kHz
Loudnes Control: +8 dB at 100 Hz; +3 dB at 10 kHz (att. 30 dB)
Frequency Range: 87,5 - 108 MHz
Antenna: 300 Ω Balanced; 75 Ω unbalanced
Intermediate Frequency: 10,7 MHz
Sensitivity at 50 dB Quieting:
Mono: 3,5μV (10,7 dB)
Stereo: 45μV (33 dB)
Sensitivity at 46 dB Quieting (at 40 kHz deviation):
Mono: 4μV (12 dB)
Stereo: 50 μV (34 dB)
Usable Sensitivity (at 40 Hz deviation):
1,8 μV (5 dB), IHF
1,6 μV (4 dB), S/N = 26 dB
S/N Ratio: 75 dB (mono); 70 dB (stereo)
At 100 Hz : 0,2% (mono); 0,3% (stereo)
At 1 kHz : 0,2% (mono); 0,3% (stereo)
At 10 kHz : 0,3% (mono); 0,5% (stereo)
IM Distortion: 0,2% (mono); 0,3% (stereo)
30 dB at 100 Hz
45 dB at 1 kHz
35 dB at 10 kHz
40 - 12,500 Hz +0 -5/-1 -0 dB
30 - 15,000 Hz +0 -5/-2 -0 dB
60 dB (400 kHz)
40 dB (300 kHz, S/N=26 dB, 40 kHz deviation)
Capture Ratio: 1,0 dB
AM Suppression Ratio: 54 dB
Image Response Ratio: 45 dB
IF Response Ratio: 90 dB
Spurious Response Ratio: 75 dB
RF Intermodulation: 60 dB
Muting Threshold: Approx. 5μV
SW : 5,8 - 15,8 MHz
MW : 530 - 1,605 kHz
LW : 150 - 350 kHz
SW/MW External antenna terminal (Attached antenna wire)
LW: Built-in Ferrite-rod antenna (External antenna terminal)
Intermediate Frequency: 468 kHz
SW: 30 μV (29,5 dB) external antenna 910 MHz)
MW: 100 μV (40 dB) external antenna (1,000 kHz)
LW: 500 μV/m (53,8 dB0 built-in antenna; 100 μV (40 dB) external antenna (230 kHz)
SW/MW: 52 dB 95 mV)
LW: 52 dB (50 mV/m)
SW/MW: o,3% (5mV, 400 Hz)
LW: 0,3% (50 mV, 400 Hz)
28 db (9 kHz)
30 dB (10 kHz)
Power Requirements: 120, 220, 240 V AC 50/60 Hz
Power Consumption: 180 W, 210 W (UK model)
Dimensions( W x H x D): 410 x 145 x 310 mm (16" x 5¾" x 12½")
Weight Net.: 7,6 kg (16 lb 13 oz)
(¹) Measured with rated output power into 8Ω loads (both channels driven simultaneously) at 1 kHz
The M75ED type2 is High Trackability Cartridge with ¾ to 1½ gramme tracking.
This new improved cartrdige offers sound re-creation performance never before available in its price class. Optimized design, parameters give superior high frequency trackability and overall performance second only to the peerless V-15 Type II Improved. Gem-quality "naked" diamond tip is mounted directly to the stylus bar to reduce effective stylus tip mass - and improve trackability. Bi-radial Elliptical Dynetic Stylus. De Luxe moulede housing assembly. An excellent cartridge choice for use in finest quality playback equipment.
400 Hz: 22 cm/sec
1,000 Hz: 33cm/sec
5,000 Hz: 28 cm/sec
10,000 Hz: 19 cm/sec
Frequency Response: 20 to 20,000 Hz
Output Voltage: 5,0 mV/channel at 1,000 Hz, 6 cm/sec
Channel Balance: within 2 dB
Channel Separation: over 25 dB at 1,000 Hz
Stylus: N75ED Type @ alliptical diamond tip
0,0007 in (0,018 mm) frontal radius
0,0002 in (0,005 mm) side contact radii
0,0010 in (0,025 mm) wids between records contact points
Tracking Force: ¾ to 1½ grammes
Recommended Load Impedance: Nominally 47,000 ohms per channel. Up to 70,000 ohms causes little audible change in frequency response.
Optimum Input Capacitance: 400 - 500 pF per channel including arm cable
Inductance: 720 mH
DC resistance: 630 ohms
Mouting Centres: Standard ¾ inch
Weight Net: 6 grammes
The JBL L150. Capable of live-performance volume levels with true deep bass reproduction and high efficiency, the JBL L150 is a worthy addition to JBL's line of outstanding loudspeaker systems. JBL designed each component of this three-way floor-standing model for maximum power-flat frequency rsponse, controlled dispersion, and extended bandwidth. The newly developed low frequency driver is the product of over two years of intensive research by JBL engineers. The result of this careful engineering is clearly audible: smooth,transparent sound at any volume level, over a frequency range extending from the lowest organ tones to the limit of audibility and beyond. JBL takes as much care with the appearance as with the sound, and the elegant columnar design occupies little floor space and fits comfortably into any room.
Advantages of the Floor-Standing Design.
While bookshelf loudspeakers systems such as the JBL L150 have reached a high degree of refinement, there are a number of significant advantages to the floor-standing design of the JBL L150. Most immediately apparent to the listener is the increased bass performance. The JBL L150 will comfortably reproduce the power of an organ or bass guitar; if the bass information is in the music, the listener will hear it. To accomplish this, JBL engineers utilized both the larger enclosure volume of the floor-standing design and a passive rediator. The bass performance of the L150 is true deep bass, without the artificial boost in the mid-bass region that often substitutes for actual low frequency reproduction. The response of the L150 extends to the lowest octaves and is completely natural in sound with no hollow quality.
Another very audible advantage of the JBL L150 is the placement of the mid range and high frequency drivers at approx. ear level of the listener. Such placement aids in the perception of the sound as being "live", and also reduces the proportion of high and mid-frequency energy that is absorbed by furniture in the room. Although placing a bookshelf system on a tall stand will produce the same effect, the L150 provides much better bass performance and is also more easily integrated visually into a room.
A loudspeaker system should do more than merely reproduce the notes. It should bring the essence of the live performance into the living room. Listen to the L150 and hear what we mean.
Each component od the JBL L150 loudspeaker system is designed and produced to meet the most rigorous standards in the audio industry. The loudspeaker frames are massive cast structures, machined to exacting tolerances. The magnetic assemblies are precisely manufactured oflow-reluctance iron, energized by powerful, high-grade magnets. Voice coils are hand wound and held within one turn of design specifications. Cones are designed from the best possible combination of stiffness, density, and weight.
The Newly developed 300 mm (12") low frequency loudspeaker produces the powerful bass of the L150. The driver utilizes a stiff, heavy cone, coated with an exclusive damping formulation (the white material on the cone) to give it optimum mass and density. The 75 mm (3") voice coil, formed of cooper ribbon and hand wound on edge, is powered by a 4,7 kg (10,25 lb) magnetic assembly. Beacuse the voice coil is unusually large for a 300 mm driver, the L150 offers exceptional transient response and high efficiency.
The magnetic assembly is the first JBL low frequency design to incorporate a ferrite magnet. Ferrite magnets have many desirable characteristics, but these have been overshadowed in conventional designs by unacceptably high (by JBL standards) levels of second-and third-harmonic distortion. However, after two years of concentrated research, JBL engineers have developed an assembly that solves the distortion problem.
One key to the new JBL design is the Symmetrical Field Geometry (SFG). Accurate reproduction of the audio signal requires that the cone and voice coil move in or out with equal facility. This does not happen in conventional designs because the magnetic field around the voice coil gap is not symetrical; such designs generate large amounts of third-harmonic distortion. JBL's new SFG design greatly reduces this distortion by creating a symmetrical magnetic field on both sides of the gap.
JBL has also devised an innovative solution to the problem of second-harmonic distortion. As the voice coil moves in the gap in a conventional ferrite design, the electrical field produced by the coil (from the audio signal) modulates the flux in the magnetic structure. This in turn affects cone movement and generates from 3% to 5% second-harmonic distortion. JBL engineers found an ingenious solution - the Flux Stabilizer, an aluminum ring surrounding the pole piece. The Flux Stabilizer minimizes this flux modulation and thereby reduces second-harmonic distortion to 0,01% or less.
The low frequency reproduction of this driver is not only powerful, but clean, exhibiting a depth and transparency seldom encountered outside a live performance.
A 300 mm (12") passive radiator extends bass response to the lowest octaves. The passive radiator, essentially a loudspeaker cone with no magnet or voice coil but of a precise mass, takes the place of a large volume of air and allows the L150 to achieve its deep bass in an enclosure of modest size. Similar performance from a conventionally ported system would require a much larger enclosure; a completely sealed (acoustic suspension) design would be much less efficient.
The 130 mm (5") midrange driver, housed in an isolated sub-chamber to prevent interaction with the low frequency loudspeaker, delivers clear, undistorted reproduction, even at extremely high volume levels. The combination of a stiff cone and large voice coil (22 mm, 7/8") give this driver exceptionally good transient response, crucial to accurate reproduction. The midrange driver is designed to be more efficient than the low frequency loudspeaker in order to maintain the substantial reserve dynamic range necessary to reproduce high-intensity program peaks without strain or distortion. (This reserve dynamic range is important because most music has far more energy in the midrange than in the bass or treble regions.)
The 25 mm (1") dome radiator produces high acoustic output with exceptional clarity and dispersion. The dome is constructed from phenolic-impregnated linen and combines stiffness with light weight; it is small enough to provide the dispersion necessary for excellent stereo imaging, yet strong enough to produce live-performance volume levels without distorting. Special clamping rings assure linear movement to further aid in distortion-free performance.
Frequenvy Dividing Network
The dividing network receives the signal from the amplifier and allocates each portion to the appropriate driver. The sophisticated network of the L150 utilizes phase-correcting and impedance-leveling circuitry so that the drivers operate through the transition frequencies in a manner approaching the theoretical ideal. All of the network components are mounted on a single large printed circuit board, which improves the already excellent reliability. The driving network of the JBL L150 does its job so well that the listener will never be aware of separate drivers - just the smooth, transparent sound.
Controls for midrange and high frequency output accomodate variations in room acoustic and personal preferences.
A tightly constructed, non-resonant enclosure is important to any loudspeaker system and especially importand to a robust system such as the L150. Therefore, the enclosure panels are made of dense compressed wood, superior to solid wood in its acoustic properties. For maximum strength and resistance to vibration, all panels are cut from 19 mm (3/4") stock. In addition all joints are hand fitted and heat cured. To absorb unwanted resonances, the enclosure is lined with fiberglass. The finish veneer is American black walnut, hand-rubbed to alustrous finish.
The JBL L150 will produce sound at comfortable listening levels when driven by an amplifier having an output of as little as 10 watts continuous sine wave per channel. However, the L150 combines high efficiency with high power capacity; for the best possible performance, an amplifier capable of delivering up to 300 watts continuous sine wave per channel is recommended. Such an amplifier has the reserve power necessary for accurate reproduction of transients, which can reach momentary peaks equivalent to ten times the average power level.
JBL has traditionally refrained from listing data for which no widely accepted test procedures have been establoshed. In the absence of such standards, any laboratory can legitimately produce a variety of values, depending on the conditions selected.
Max. Recommended Amplifier Power: 300 watts per channel
Nominal Impedance: 8 ohms
Crossover Frequencies: 1,000 Hz; 4,000 Hz
System Sensitivity: 88 dB SPL, (1W/1m)
Low Fequency Loudspeakers
Nominal Diameter: 300 mm (12 inch)
Voice Coil: 76 mm (3 inch) copper
Magnetic Assembly Weight: 4,7 kg (10¼ lbs)
Flux Density: 1.05 tesla (10,500 gauss)
Sensitivity (Averaged from 100 Hz to 500 Hz, within 1 dB): 89 dB SPL (1W/1m)
Nominal Diameter: 130 mm (5 inch)
Voice Coil: 22 mm (⅞ inch) copper
Magnetic Assembly Weight: 0,74 kg (1⅝ lbs)
Flux Density: 1,4 tesla (14,000 gauss)
Sensitivity (Averaged from 1 kHz to 3 kHz, within 1 dB): 91 dB SPL (1W/1m)
High Frequency Dome Radiator
Nominal Diameter: 25 mm ( 1 inch)
Voice Coil: 25 mm (1 inch) aluminum
Magnetic Assembly Weight: 0,68 kg (1½ lbs)
Flux Density: 1,4 tesla (14,000 gauss)
Sensitivity (Averaged above 5 kHz, within 1 dB): 90 dB SPL (1W/1m)
Finish: Oiled walnut
Grille Colors: Brown, rust, camel
Dimensions (W x H x D): 1054 x 432 x 330 mm (41½ x 17 x 13 inch)
Weight (net): 36,4 kg (80 lbs)