There are a number of electronic devices and kits of particular interest to the DIY speaker builder. Among these are dedicated subwoofer amps (both built-in and external), general purpose amps especially suitable for multi- amp'ing, electronic crossovers and line level filter kits, test and measurement tools, etc. This section is a list of known and recommended resources. As with the rest of the LDSG, only devices for which I have received specific recommendations are listed.
Covered devices include:
The following subwoofer amplifier are designed to be built in to a subwoofer enclosure. Designed to mount flush to the surface of an enclosure, these are popularly known as "plate" amplifiers. Amplifier RMS power ratings and specific features are noted. All include automatic power on/off in addition to a power switch, except as noted. Listed alphabetically by manufacturer.
Summarizing the recommendations I've received, Madisound is the most popular (which is why its amps are available from several other vendors). RCM Akustik offers the highest quality and greatest versatility. Apex Jr. and Stryke Audio offer the lowest prices for those on a budget. Adire Audio has been consistently plaised for its customer service and its HS500 offers the most power. BK is a new entry, but based solely on their specifications and the quality of their amplifier modules (see Amplifier modules below), they probably rank close to RCM.
Sold direct from the Adire Audio web site.
1. AVA150 - 110W @ 8 ohms, 150 W @ 4 ohms - class AB
Price: $149.
Features: THD = <1%
S/N = >95 dB
Crossover frequency: 60-125 Hz, continuously variable
Crossover slope: 12 dB/octave
Other EQ: Bass boost - 1 dB at 25 Hz
Subsonic filter - 12 dB/octave, Q=0.96 @ 18 Hz
Satellite filter - No
Phase control: Inverting switch
Inputs: Low & high level, summed to mono
Sensitivity (low level) = 85 mV
Sensitivity (high level) = 1 V
Input impedance = 47 Kohm
Cutout: 8 x 8 in. (203.2 x 203.2 mm)
Weight: 9 lbs (4.08 kg)
2. AVA250 - 180W @ 8 ohms, 250 W @ 4 ohms - class AB
Price: $179.
Features: THD = <0.1%
S/N = >103 dB
Crossover frequency: 40-160 Hz, continuously variable
Crossover slope: 12 dB/octave
Other EQ: Bass boost - 1 dB @ 25 Hz
Subsonic filter - 12 dB/octave, Q=0.96 @ 18 Hz
Satellite filter - 6 dB/octave @ 125 Hz high level only
Phase control: Continuously variable, 0-180 degrees
Inputs: Low & high level, summed to mono
Sensitivity (low level) = 85 mV
Sensitivity (high level) = 2.83 V
Input impedance = 20 kOhm
Cutout: 9.5 x 9.5 in. (241.3 x 241.3 mm)
Weight: 12 lbs (5.44 kg)
3. HS500 - 490W @ 8 ohms, 720 W @ 4 ohms - class H. Two-piece unit comprising the
amplifier/control panel and a separate internally-mounted power
supply.
Price: $499.
Features: THD = <0.05%
S/N = >105 dB
Crossover frequency: 50-150 Hz, continuously variable
Crossover slope: 24 dB/octave
Other EQ: Bass boost - 1 dB @ 18 Hz
Subsonic filter - 12 dB/octave, Q=0.96 @ 12 Hz
Satellite filter - 24 dB/octave @ 50-150 Hz,
continuously variable independent of subwoofer crossover
Phase control: Inverting switch
Inputs: Low level summed to mono
Sensitivity (low level) = 1V
Sensitivity (high level) = N.A.
Input impedance = 10 Kohms
Cutout: Amplifier - 6 x 13.75 in. (152.4 x 349.3 mm)
Power supply - Not Needed (internal mount)
6" w x 13.75" l by 5" h
(152.4 x 349.3 x 127 mm)
Weight:
Amplifier - 8 lbs (3.63 kg)
Power supply - 16 lbs (7.26 kg)
Apex Jr.:
Sold direct from the Apex Jr. web site.
1. Apex "Junior" - 100W @ 8 ohms, 130 W @ 4 ohms - class AB.
Price: $90. Also available with 115V/230V version with detachable cord:
$95.00.
Features: THD = <0.1%
S/N = >70 dB
Crossover frequency: 60-125 Hz, continuously variable
Crossover slope: 12 dB/octave
Other EQ: Bass boost - No
Subsonic filter - No
Satellite filter - No
Phase control: Inverting switch
Inputs: Low & high level, summed to mono
Sensitivity (low level) = 85 mV
Sensitivity (high level) = 1 V
Input impedance = 47 Kohm
Cutout: 8 x 8 in. (203.2 x 203.2 mm)
Weight: 9 lbs (4.08 kg)
2. Apex "Senior" - 250W @ 8 ohms, 350 W @ 4 ohms - class AB.
Price: $225 (115/230V 50/60Hz).
Features: THD = <0.1%
S/N = >101 dB
Crossover frequency: 40-160 Hz, continuously variable
Crossover slope: 12 dB/octave
Other EQ: Bass boost - 6 dB @ 30 Hz
Subsonic filter - No
Satellite filter - 6 dB @ 125 Hz
Phase control: 0-180 degrees
Inputs: Low & high level, summed to mono
Sensitivity (low level) = 156 mV
Sensitivity (high level) = 3.75 V
Input impedance = >20 Kohm
Cutout: 11.25 x 9.25 in. (285.75 x 234.95 mm)
Weight: 12 lbs (5.44 kg)
3. KG-5150 - 150W @ 8 ohms, 200 W @ 4 ohms - class AB.
Price: $143.
Features: THD = 0.03%
S/N = 95 dB
Crossover frequency: 50-100 Hz, continuously variable
Crossover slope: 12 dB/octave
Other EQ: Bass boost - +4 dB @ 25 Hz, fixed & unswitchable
Subsonic filter - No
Satellite filter - No
Phase control: Inverting switch
Inputs: Low & high level, summed to mono
Sensitivity (low level) = 75 mV
Sensitivity (high level) = 3.5 V
Input impedance = 22 Kohms
Cutout: 10-7/16 x 7-1/4 in. (290.5 x 184 mm)
Weight: 10.5 lbs. (4.76 kg)
Audio Concepts, Inc. (ACI):
Sold in North America by ACI.
1. PSA-1 - 150W @ 8 ohms, 200 W @ 4 ohms - class not stated.
Price: $169.
Features: THD = 0.025%
S/N = 95 dB
Crossover frequency: 50-100 Hz, continuously variable
Crossover slope: 12 dB/octave
Other EQ: Bass boost - +4 dB @ 25 Hz, fixed & unswitchable
Subsonic filter - No
Satellite filter - No
Phase control: Inverting switch
Inputs: Low & high level, summed to mono
Sensitivity (low level) = 150 mV
Sensitivity (high level) = 2 V
Input impedance = 22 Kohms
Cutout: 10-7/16 x 7-1/4 in. (290.5 x 184 mm)
Weight: 10.5 lbs. (4.76 kg)
BK Electronics:
Sold in North America by
Old Colony Sound Lab.
Sold in Europe directly by BK Electronics in the UK.
1. BSBP 200 - 210 W @ 8 ohms, 205 W @ 4 ohms - class not stated.
Price: $220.
Features: THD = 0.05%
S/N = 100 dB
Crossover frequency: 40-120 Hz, continuously variable
Crossover slope: 12 dB/octave
Other EQ: Bass boost - No
Subsonic filter - -3 dB @ 10 Hz
Satellite filter - No
Phase control: 0-180 degrees
Inputs: Low & high level, summed to mono
Sensitivity (low level) = 150 mV
Sensitivity (high level) = 1.5 V
Input impedance = N.A.
Cutout: 9-1/2 x 9-1/2 in. (24.1 x 24.1 mm)
Weight: 11.0 lbs. (5.0 kg)
Madisound:
Sold in North America by Madisound.
The KG5150 is also sold by Speaker City.
1. KG-5150 - 150W @ 8 ohms, 200 W @ 4 ohms - class not stated.
Price: $169.
Features: THD = 0.03%
S/N = 95 dB
Crossover frequency: 50-100 Hz, continuously variable
Crossover slope: 12 dB/octave
Other EQ: Bass boost - +4 dB @ 25 Hz, fixed & unswitchable
Subsonic filter - No
Satellite filter - No
Phase control: Inverting switch
Inputs: Low & high level, summed to mono
Sensitivity (low level) = 75 mV
Sensitivity (high level) = 3.5 V
Input impedance = 22 Kohms
Cutout: 10-7/16 x 7-1/4 in. (290.5 x 184 mm)
Weight: 10.5 lbs. (4.76 kg)
2. KG-5230 - 175W @ 8 ohms, 300 W @ 4 ohms - class not stated.
Price: $225.
Features: THD = 0.08%
S/N = 85 dB
Crossover frequency = 50-100 Hz, continuously variable
Crossover slope: 12 dB/octave
Other EQ: Bass boost - +4 dB @ 25 Hz, fixed & unswitchable
Subsonic filter - No
Satellite filter - No
Phase control: Inverting switch
Inputs: Low & high level, summed to mono
Sensitivity (low level) = 150 mV
Sensitivity (high level) = 2 V
Input impedance = 22 Kohms
Cutout: 9-7/8 x 9-7/8 in. (250.8 x 250.8 mm)
Weight: 14.5 lbs. (6.71 kg)
MCM:
Sold in North America by MCM Electronics.
1. 50-4465 - 75 W @ 8 ohms, 110 W @ 4 ohms - class not stated.
Price: $179.
Features: THD = 0.01%
S/N = 96 dB
Crossover frequency = 60-160 Hz, continuously variable &
defeatable
Crossover slope: 12 dB/octave
Other EQ: Bass boost - No
Subsonic filter - No
Satellite filter - Yes
Phase control: Inverting switch
Inputs: Low & high level, summed to mono
Sensitivity (low level) = N.A.
Sensitivity (high level) = N.A.
Input impedance = N.A.
Cutout: 10 x 7 in. (254 x 178 mm)
Weight: N.A.
Meniscus:
Sold in North America by Meniscus.
1. PSA-100 - 100 W @ 8 ohms, 150 W @ 4 ohms - class not stated.
Price: $149.
Features: THD = 0.1%
S/N = N.A.
Crossover frequency = 40-200 Hz, continuously variable &
defeatable
Crossover slope: 12 dB/octave
Other EQ: Bass boost - No
Subsonic filter - No
Satellite filter - No
Phase control: Inverting switch
Inputs: Low & high level, summed to mono
Sensitivity (low level) = N.A.
Sensitivity (high level) = N.A.
Input impedance = N.A.
Cutout: 9 x 8 in. (229 x 203 mm)
Weight: N.A.
2. PSA-150 - 150 W @ 8 ohms, 200 W @ 4 ohms - class not stated.
Price: $169.
Features: THD = 0.025%
S/N = N.A.
Crossover frequency = 50-100 Hz, continuously variable &
defeatable
Crossover slope: 12 dB/octave
Other EQ: Bass boost - No
Subsonic filter - No
Satellite filter - No
Phase control: Inverting switch
Inputs: Low & high level, summed to mono
Sensitivity (low level) = N.A.
Sensitivity (high level) = N.A.
Input impedance = N.A.
Cutout: 10-7/16 x 7-1/4 in. (290.5 x 184 mm)
Weight: N.A.
3. PSA-175 - 175 W @ 8 ohms, 300 W @ 4 ohms - class not stated.
Price: $225.
Features: THD = N.A.
S/N = N.A.
Crossover frequency = 50-100 Hz, continuously variable &
defeatable
Crossover slope: 12 dB/octave
Other EQ: Bass boost - No
Subsonic filter - No
Satellite filter - No
Phase control: Inverting switch
Inputs: Low & high level, summed to mono
Sensitivity (low level) = N.A.
Sensitivity (high level) = N.A.
Input impedance = N.A.
Cutout: N.A.
Weight: N.A.
Parts Express:
Sold in North America by Parts Express.
1. 300-795 - N.A. W @ 8 ohms, 250 W @ 4 ohms - class D.
Price: $249.
Features: THD = 0.1%
S/N = 100 dB
Crossover frequency = 40-160 Hz, continuously variable
Crossover slope: 12 dB/octave
Other EQ: Bass boost - No
Subsonic filter - No
Satellite filter - 6 dB @ 90 Hz
Phase control: Inverting switch
Inputs: Low & high level, summed to mono
Sensitivity (low level) = N.A.
Sensitivity (high level) = N.A.
Input impedance = N.A.
Cutout: 9.5 x 9.5 in. (241 x 241 mm)
Weight: 4 lbs. (1.81 kg)
RCM Akustik:
Sold in North America by Jack Burnett Associates.
1. DT100II - 100 W @ 8 ohms, 100 W @ 4 ohms - class G.
Price: $189.
Features: THD = <0.01%
S/N = >100 dB
Crossover frequency = 50-150 Hz, continuously variable
Crossover slope: 12 dB/octave
Other EQ: Bass boost - 0, +3, +6 dB @ 30 Hz, switchable
Subsonic filter - 20 Hz, Slope not specified
Satellite filter - 100 Hz, Slope not specified
Phase control: 0-180 degrees
Inputs: Low & high level, summed to mono
Sensitivity (low level) = 20 mV
Sensitivity (high level) = 950 mV
Input impedance = N.A.
Cutout: 7-1/4 x 7-1/4 in. (184 x 184 mm)
Weight: 9 lbs. (4.1 kg)
2. DT110II - 125 W @ 8 ohms, 150 W @ 4 ohms - class G.
Price: $219.
Features: THD = <0.01%
S/N = >100 dB
Crossover frequency = 50-150 Hz, continuously variable
Crossover slope: 12 dB/octave
Other EQ: Bass boost - 0, +3, +6 dB @ 30 Hz, switchable
Subsonic filter - 20 Hz, Slope not specified
Satellite filter - 100 Hz, Slope not specified
Phase control: 0-180 degrees
Inputs: Low & high level, summed to mono
Sensitivity (low level) = 12 mV
Sensitivity (high level) = 580 mV
Input impedance = N.A.
Cutout: 7-1/4 x 7-1/4 in. (184 x 184 mm)
Weight: 9 lbs. (4.1 kg)
Stryke Audio:
Sold direct from the Stryke Audio web site.
1. AMP130 - 100W @ 8 ohms, 130 W @ 4 ohms - class not stated.
Price: $90.
Features: THD = <0.1%
S/N = >70 dB
Crossover frequency: 60-125 Hz, continuously variable
Crossover slope: 12 dB/octave
Other EQ: Bass boost - N.A.
Subsonic filter - N.A.
Satellite filter - N.A.
Phase control: Inverting switch
Inputs: Low & high level, summed to mono
Sensitivity (low level) = N.A.
Sensitivity (high level) = N.A.
Input impedance = 47 Kohm
Cutout: 8 x 8 in. (203.2 x 203.2 mm)
Weight: 9 lbs (4.08 kg)
2. AMP350 - 250W @ 8 ohms, 350 W @ 4 ohms - class not stated.
Price: $225.
Features: THD = <0.1%
S/N = >101 dB
Crossover frequency: 40-160 Hz, continuously variable
Crossover slope: N.A.
Other EQ: Bass boost - +6 dB @ 30 Hz (removable, optionally +1 dB @ 23 Hz)
Subsonic filter - -3 dB @ 18 Hz (removable)
Satellite filter - N.A.
Phase control: Continuously variable 0-180 degrees
Inputs: Low & high level, summed to mono
Sensitivity (low level) = N.A.
Sensitivity (high level) = N.A.
Input impedance = N.A.
Cutout: 11.25 x 9.25 in. (285.75 x 234.95 mm)
Weight: 12 lbs (5.44 kg)
3. KG-5150 - 150W @ 8 ohms, 200 W @ 4 ohms - class not stated.
Price: $169.
Features: THD = 0.03%
S/N = 95 dB
Crossover frequency: 50-100 Hz, continuously variable
Crossover slope: 12 dB/octave
Other EQ: Bass boost - +4 dB @ 25 Hz, fixed & unswitchable
Subsonic filter - No
Satellite filter - No
Phase control: Inverting switch
Inputs: Low & high level, summed to mono
Sensitivity (low level) = 75 mV
Sensitivity (high level) = 3.5 V
Input impedance = 22 Kohms
Cutout: 10-7/16 x 7-1/4 in. (290.5 x 184 mm)
Weight: 10.5 lbs. (4.76 kg)
4. KG-5230 - 175W @ 8 ohms, 300 W @ 4 ohms - class not stated.
Price: $225.
Features: THD = 0.08%
S/N = 85 dB
Crossover frequency = 50-100 Hz, continuously variable
Crossover slope: 12 dB/octave
Other EQ: Bass boost - +4 dB @ 25 Hz, fixed & unswitchable
Subsonic filter - No
Satellite filter - No
Phase control: Inverting switch
Inputs: Low & high level, summed to mono
Sensitivity (low level) = 150 mV
Sensitivity (high level) = 2 V
Input impedance = 22 Kohms
Cutout: 9-7/8 x 9-7/8 in. (250.8 x 250.8 mm)
Weight: 14.5 lbs. (6.71 kg)
Dedicated subwoofer amplifiers (stand-alone):
The following subwoofer amplifier are designed to be installed remotely from
the subwoofer enclosure. Amplifier RMS power ratings and specific features
are noted. All include automatic power on/off in addition to a power switch,
except as noted. Listed alphabetically by manufacturer.
Speaker City:
Sold in North America by Speaker City.
1. SAM-200 - 120W @ 8 ohms, 160 W @ 4 ohms - class not stated.
Price: $279.
Features: THD = <0.01%
S/N = N.A.
Crossover frequency: 40-200 Hz, continuously variable
Crossover slope: 18 dB/octave
Other EQ: Bass boost - No
Subsonic filter - No
Satellite filter - Yes
Phase control: Inverting switch
Inputs: Low & high level, summed to mono
Sensitivity (low level) = 75 mV
Sensitivity (high level) = 3.5 V
Input impedance = 22 Kohms
Amplifier modules:
The following mono amplifiers are not specifically designed for subwoofer
use. Amplifier RMS power ratings and specific features are noted. All are
open frame designs which will require some sort of case. Listed
alphabetically by manufacturer.
Summarizing the recommendations I've received, the BK modules are outstanding
values, offering excellent specs for less money than most others. They also
are reported to sound great. All of Velleman's products have also been
recommended.
BK Electronics:
Sold in North America by
Old Colony Sound Lab.
Sold in Europe directly by BK Electronics in the UK.
1. MF100 - 105 W @ 8 ohms, 115 W @ 4 ohms - MOSFET, class not stated
Price: $140.
Features: Power bandwidth = 1 Hz - 100 kHz
THD = <0.001%
S/N = 110 dB
Slew rate = 45 V/uS
Damping factor = >300
Input impedance = 10 kOhms
Input sensitivity = 500 mV
Power supply: Included
Size: 11.8 x 5 x 3.15 in. (300 x 127 x 8 Ohm)
Weight: 4.85 lbs. (2.2 kg)
2. MF200 - 150 W @ 8 ohms, 215 W @ 4 ohms - MOSFET, class not stated
Price: $220.
Features: Power bandwidth = 1 Hz - 100 kHz
THD = <0.01%
S/N = 110 dB
Slew rate = 60 V/uS
Damping factor = >300
Input impedance = 10 kOhms
Input sensitivity = 500 mV
Power supply: Included
Size: 11.8 x 6.1 x 4 in. (300 x 155 x 102 mm)
Weight: 8.82 lbs. (4 kg)
3. MF300 - 220 W @ 8 ohms, 310 W @ 4 ohms - MOSFET, class not stated
Price: $270.
Features: Power bandwidth = 1 Hz - 100 kHz
THD = <0.0035%
S/N = 110 dB
Slew rate = 60 V/uS
Damping factor = gt; 300
Input impedance = 10 kOhms
Input sensitivity = 500 mV
Power supply: Included
Size: 11.8 x 6.89 x 4 in. (330 x 175 x 102 mm)
Weight: 10.58 lbs. (4.8 kg)
4. MF450 - 305 W @ 8 ohms, 455 W @ 4 ohms - MOSFET, class not stated
Price: $400.
Features: Power bandwidth = 1 Hz - 100 kHz
THD = <0.001%
S/N = 110 dB
Slew rate = 75 V/uS
Damping factor = >300
Input impedance = 10 kOhms
Input sensitivity = 500 mV
Power supply: Included
Size: 15.16 x 8.27 x 4.13 in. (385 x 210 x 105 mm)
Weight: 15.4 lbs. (7 kg)
5. MF1000 - 725 W @ 8 ohms, 1050 W @ 4 ohms - MOSFET, class not stated
Price: $700.
Features: Power bandwidth = 1 Hz - 100 kHz
THD = <0.001%
S/N = 110 dB
Slew rate = 75 V/uS
Damping factor = >300
Input impedance = 10 kOhms
Input sensitivity = 500 mV
Power supply: Included
Size: 16.6 x 11.81 x 4.92 in. (422 x 300 x 125 mm)
Weight: 36 lbs. (16.3 kg)
Marchand:
Marchand is available direct from Marchand or through numerous distributors.
1. PM2 - 75 W @ 8 ohms, 75 W @ 4 ohms - Darlington bipolar,, class not
stated
Price: $100 complete, $80 kit
Features: Power bandwidth = 2 Hz - 20 kHz
THD = <0.02%
S/N = N.A.
Slew rate = N.A.
Damping factor = N.A.
Input impedance = 100 kOhms
Input sensitivity = 100 mV
Power supply: Not included
Size: 3 x 5 x 2.5 in. (76 x 127 x 63.5 mm)
Weight: N.A.
Velleman:
Velleman is available direct from Velleman or through numerous distributors.
Velleman is distributed in North America by AudioXpress.
1. K4010 - 100 W @ 8 ohms, 155 W @ 4 ohms - MOSFET, pseudo-class A
Price: $215.
Features: Power bandwidth = 5 Hz - 50 kHz
THD = <0.008%
S/N = 110 dB
Slew rate = 75 V/uS
Damping factor = >600
Input impedance = 47 kOhms
Input sensitivity = 1 V
Power supply: Included
Size w/o xfmr: 13.78 x 3.51 x 3.54 in. (350 x 140 x 90 mm)
Weight: N.A.
2. K8011 - 90 W @ 8 ohms, 90 W @ 4 ohms - tube/valve, class not stated
Price: $599.
Features: Power bandwidth = 2 Hz - 125 kHz
THD = <0.1%
S/N = 104 dB
Slew rate = N.A.
Damping factor = N.A.
Input impedance = N.A.
Input sensitivity = 1 V
Power supply: Included
Size w/o xfmr: 12.6 x 13.6 x 5.12 in. (320 x 345 x 130 mm)
Weight: N.A.
Stereo amplifier kits:
The following amplifiers are complete kits, including power supply and
enclosure. Listed alphabetically by manufacturer.
Marchand:
Marchand sells most of their products assembled, as kits, or as EZ kits (most
of the hard work already done).
Marchand is available direct from Marchand or through numerous distributors.
1. MB201 2x125 W @ 4 ohms, 200 W @ 4 ohms - MOSFET, class AB
2X50 W @ 4 or 8 ohms - MOSFET. class A (add $25)
Price: $595 kit, $695 EZ kit, $995 assembled
Features: Power bandwidth = 10 Hz - 20 kHz
THD = 0.02%
S/N = N.A.
Slew rate = N.A.
Damping factor = N.A.
Input impedance = 25 Kohm
Input sensitivity = N.A.
Size: 7.75 x 5 x 12.5 in. (197 x 127 x 317.5 mm)
Weight: N.A.
Velleman:
Velleman is available direct from Velleman or through numerous distributors.
Velleman is distributed in North America by AudioXpress.
1. K4020 - 2x100 W @ 8 ohms, 2x155 W @ 4 ohms - MOSFET, pseudo-class A
Price: $479.
Note: This is essentially two 4010 modules in a case.
Features: Power bandwidth = 5 Hz - 50 kHz
THD = <0.008%
S/N = 110 dB
Slew rate = 75 V/uS
Damping factor = >600
Input impedance = 47 kOhms
Input sensitivity = 1 V
Size: 16.7 x 3.5 x 14 in. (425 x 90 x 355 mm)
Weight: 24 lbs. (11 Kg)
2. K4040 2x15 W @ 4 or 8 ohms - tube/valve, class A
2x90 W @ 4 or 8 ohms - tube/valve, class AB
Price: $1,000.
Features: Power bandwidth = 15 Hz - 40 kHz
THD = 0.1% (0.7% @ 90 W)
S/N = 105 dB
Slew rate = N.A.
Damping factor = >10
Input impedance = 34 kOhms
Input sensitivity = N.A.
Size: 16.7 x 5.1 x 13.8 in. (425 x 130 x 350 mm)
Weight: N.A.
Monoblock amplifiers:
The following amplifiers are monoblocks, not normally available through usual
hi-fi distribution, but which have been recommended for DIY use. Some are kits
Listed alphabetically by manufacturer.
Atma-Sphere:
Atma-Sphere specializes in highly-regarded output transformer-less (OTL)
vacuum tube (valve) technology.
Atma-Sphere is available directly from Atma-Sphere
1. Novacron kit - mono 60 W @ 8 ohms - tube/valve (OTL), class A
Price: $1,750/pr
Features: Power bandwidth = 2 Hz - 75 kHz
THD = N.A.
S/N = 104 dB
Slew rate = N.A.
Damping factor = N.A.
Input impedance = N.A.
Input sensitivity = N.A.
Size: N.A.
Weight: 54 lbs. (24.5 Kg)
2. M-60 Mark II kit - mono 60 W @ 8 ohms, 45 W @ 4 ohms - tube/valve (OTL),
class A
Price: $2,495/pr
Features: Power bandwidth = 2 Hz - 75 kHz
THD = N.A.
S/N = 104 dB
Slew rate = N.A.
Damping factor = N.A.
Input impedance = N.A.
Input sensitivity = N.A.
Size: N.A.
Weight: 54 lbs. (24.5 Kg)
Marchand:
Marchand sells most of their products assembled, as kits, or as EZ kits (most
of the hard work already done).
Marchand is available direct from Marchand or through numerous distributors.
1. MB201 250 W @ 4 ohms, 150 W @ 8 ohms - MOSFET, class AB
Price: $495 kit, $595 EZ kit, $795 assembled
Features: Power bandwidth = 10 Hz - 20 kHz
THD = 0.02%
S/N = N.A.
Slew rate = N.A.
Damping factor = N.A.
Input impedance = 25 Kohm
Input sensitivity = N.A.
Size: 7.75 x 5 x 12.5 in. (197 x 127 x 317.5 mm)
Weight: N.A.
JOB:
JOB amplifiers are little-known, but highly respected professional
amplifiers. Although JOB makes both monoblock and stereo amplifiers, only the
monoblocks are listed here.
JOB is available direct from JOB.
1. The JOB Mono - 200 W @ 3 ohms - type and class not stated
Price: $1,250
Features: Power bandwidth = DC - 1 mHz
THD = N.A.
S/N = N.A.
Slew rate = N.A.
Damping factor = N.A.
Input impedance = N.A.
Input sensitivity = N.A.
Size: 6 x 2 x 10 in. (152.4 x 50.8 x 254 mm)
Weight: 7.7 lbs. (3.5 Kg)
2. JOB 200 - 200 W @ 8 ohms - type and class not stated
Price: $999
Features: Power bandwidth = DC - 1 mHz
THD = N.A.
S/N = N.A.
Slew rate = N.A.
Damping factor = N.A.
Input impedance = N.A.
Input sensitivity = N.A.
Size: 5 x 4 x 8 in. (127 x 101.6 x 203.2 mm)
Weight: 7.7 lbs. (3.5 Kg)
Velleman:
Velleman is available direct from Velleman or through numerous distributors.
Velleman is distributed in North America by AudioXpress.
1. K8010 - 65 W @ 4 or 8 ohms - tube/valve, class A
Price: $1,095.
Features: Power bandwidth = 8 Hz - 80 kHz
THD = 0.1%
S/N = 110 dB
Slew rate = N.A.
Damping factor = N.A.
Input impedance = N.A.
Input sensitivity = 1 V
Size: 13.8 x 13.8 x 6.3 in. (360 x 360 x 160 mm)
Weight: N.A.
Marchand:
Marchand sells most of their products assembled, as kits, or as EZ kits (most
of the hard work already done).
Marchand is available direct from Marchand or through numerous distributors.
1. MB200 100 W @ 1, 2, 4, 8, or 16 ohms - MOSFET, class A
Price: $995 kit, $1,195 EZ kit, $1,995 assembled
Features: Power bandwidth = 10 Hz - 20 kHz
THD = 0.01%
S/N = N.A.
Slew rate = N.A.
Damping factor = N.A.
Input impedance = 25 Kohm
Input sensitivity = N.A.
Size: 9.25 x 5 x 12.5 in. (235 x 127 x 317.5 mm)
Weight: N.A.
Electronic crossovers:
The following electronic crossovers are designed to be used upstream of a
system's power amplifiers. This list includes both kits and fully assembled
units. Listed alphabetically by manufacturer.
AudioControl:
AudioControl is a specialized vendor of electronic equalizers. They also sell
a single, well-regarded specialized dedicated woofer crossover.
AudioControl is available through a network of authorized distributors.
1. Richter Scale Series 3, stereo, 2-way - 24 dB/octave Linkwitz-Riley
Price: $349
The Richter Scale Series 3 is a combination electronic crossover with a 5
band, 1/2 octave equalizer.
Features: Frequency selection: By plug-in module.
Level: 5-Band, stereo common, +/- 12 dB
Damping: Fixed
Phase: N.A.
Summing (subwoofer) out: Yes
Time delay: None
Frequency readout: None
Frequency response: 3 Hz - 100 kHz
THD = <0.005%
S/N = >120 dB
Gain = 0 dB
Input impedance = N.A.
Output impedance = N.A.
Maximum input = N.A.
Maximum output = N.A.
Size: 17 x 8 x 2.5 in. (432 x 216 x 63.5 mm)
Weight: N.A.
Hsu Research:
Hsu Research is a specialized vendor of subwoofers and related products.
Hsu Research is available either directly, or through a network of authorized
distributors.
1. High Definition Crossover, stereo, 2-way - 24 dB/octave Linkwitz-Riley
Price: $349
Features: Frequency selection: By plug-in module. 28 - 155 Hz.
Level: Single control.
Damping: Fixed
Phase: Inversion switch.
Summing (subwoofer) out: Yes
Time delay: None
Frequency readout: None
Frequency response: N.A.
THD = N.A.
S/N = N.A.
Gain = 0 dB
Input impedance = 100 Kohm
Output impedance = N.A.
Maximum input = N.A.
Maximum output = N.A.
Size: 8.4 x 5.4 x 2.3 in. (213 x 137 x 5.8 mm)
Weight: 3 lbs. (1.4 Kg)
Marchand:
Marchand sells most of their products assembled, as kits, or as EZ kits (most
of the hard work already done).
Marchand is available direct from Marchand or through numerous distributors.
1. XM6 stereo, 2-way - 24 dB/octave Linkwitz-Riley
Price: $495 EZ kit, $694 assembled
Features: Frequency selection: Digital, front panel up/down switches
select from 163 discreet frequencies
from 20 to 5k Hz.
Level: Individual per channel, -8 to +4 dB
Damping: Common control, -3 to +6 dB
Phase: One inverting switches per channel
Summing (subwoofer) out: Yes
Time delay: None
Frequency readout: 4-digit LED
Frequency response: 2 Hz - 100 kHz
THD = <0.01%
S/N = >110 dB
Gain = 0 dB
Input impedance = 50 Kohm
Output impedance = 10 ohm
Maximum input = +/-12.5 V
Maximum output = +/-12.5 V
Size: 17 x 8.5 x 2.8 in. (432 x 216 x 71 mm)
Weight: N.A.
2. XM9 stereo, 2-way - 24 dB/octave Linkwitz-Riley
Price: $249 kit, $299 EZ kit, $399 assembled (standard)
Price: $299 kit, $349 EZ kit, $499 assembled (deluxe)
Frequency modules: $2 /each (kit), $4 /each (assembled)
Note: Deluxe version adds upgraded op amps and connectors.
Features: Frequency selection: 20 to 5k Hz by plug-in modules.
Level: Individual per channel, 0 (off) to +6 dB
Damping: Fixed
Summing (subwoofer) out: Yes
Time delay: None
Frequency readout: None
Frequency response: DC - 100 kHz
THD = <0.01%
S/N = >110 dB
Gain = 0 dB
Input impedance = 50 Kohm
Output impedance = 50 ohm
Maximum input = +/-12.5 V
Maximum output = +/-12.5 V
Size: 17 x 8.5 x 2.8 in. (432 x 216 x 71 mm)
Weight: N.A.
3. XM16 stereo, 2-way - 48 dB/octave Linkwitz-Riley
Price: $299 kit, $349 EZ kit, $449 assembled (standard)
Price: $349 kit, $399 EZ kit, $549 assembled (deluxe)
Frequency modules: $4 /each (kit), $6 /each (assembled)
Note: Deluxe version adds upgraded op amps and connectors.
Features: Frequency selection: 20 to 5k Hz by plug-in modules.
Level: Individual per channel, -8 to +4 dB
Damping: Fixed
Summing (subwoofer) out: Yes
Time delay: None
Frequency readout: None
Frequency response: DC - 100 kHz
THD = <0.01%
S/N = >110 dB
Gain = 0 dB
Input impedance = 100 Kohm
Output impedance = 50 ohm
Maximum input = +/-12.5 V
Maximum output = +/-12.5 V
Size: 17 x 8.5 x 2.8 in. (235 x 127 x 317.5 mm)
Weight: N.A.
4. XM26 stereo, 2-way - 24 dB/octave Linkwitz-Riley, tube/valve design
Price: $689 kit, $800 EZ kit, $1,495 assembled
Frequency modules: $7 /each (kit), $10 /each (assembled)
Features: Frequency selection: 20 to 5k Hz by plug-in modules.
Level: Individual per channel, -1 to 0 dB
Damping: Fixed
Summing (subwoofer) out: Yes
Time delay: None
Frequency readout: None
Frequency response: 5 Hz - 100 kHz
THD = <0.1%
S/N = >110 dB
Gain = 0 dB
Input impedance = 1 Mohm
Output impedance = 500 ohm
Maximum input = +/-25 V
Maximum output = +/-25 V
Size: 17 x 8.5 x 2.8 in. (235 x 127 x 317.5 mm)
Weight: N.A.
Rane:
Rane is a highly-respected vendor specializing in pro sound equipment. A
number of their products have been adopted for home use by DIY'ers.
Rane is available from a network of Rane pro audio distributors.
1. AC22 stereo, 2-way or mono 3-way - 24 dB/octave Linkwitz-Riley
Price: $369
Features: Frequency selection: 16 discreet frequencies from 70 to
3.6k Hz.
Level: Individual per channel, 0 to +6 dB
Damping: None
Phase: None
Summing (subwoofer) out: Yes
Time delay: 0 - 2 ms.
Frequency readout: None
Frequency response: 20 Hz - 40 kHz, filtered
THD = <0.02%
S/N = >92 dB
Gain = 0-6 dB
Input impedance = 20 Kohm
Output impedance = 200 ohm
Maximum input = +21 dBu
Maximum output = +20 dBu
Size: 19 x 5.3 x 1.75 in. (483 x 133 x 44 mm)
Weight: 4 lbs. (3 Kg)
2. AC23 stereo, 3-way or mono 5-way - 24 dB/octave Linkwitz-Riley
Price: $450
Features: Frequency selection (lo): 11 discreet frequencies from 70 to
1k Hz.
Frequency selection (hi): 14 discreet frequencies from 190 to
7k Hz.
Level: Individual per channel, 0 to +6 dB
Damping: None
Phase: None
Summing (subwoofer) out: Yes
Time delay: 0 - 2 ms.
Frequency readout: None
Frequency response: 20 Hz - 40 kHz, filtered
THD = <0.01%
S/N = >110 dB
Gain = 0-6 dB
Input impedance = 20 Kohm
Output impedance = 200 ohm
Maximum input = +21 dBu
Maximum output = +20 dBu
Size: 19 x 5.3 x 1.75 in. (483 x 133 x 44 mm)
Weight: 5 lbs. (2.3 Kg)
Paradigm:
Paradigm is a highly-respected vendor of loudspeaker systems. They also have
a line of electronic crossovers.
Paradigm is available from a network of Paradigm distributors.
1. X-20 stereo, 2-way - 18 dB/octave
Price: $159
Note: This unit features speaker level inputs. Outputs are speaker level
high pass (6 dB/octave @ 125 Hz), and line level subwoofer.
Features: Frequency selection: 35 to 150 Hz, continuously variable.
Level: Individual per channel, 0 to +6 dB
Damping: None
Phase: Variable, 0-180 degrees
Summing (subwoofer) out: No
Time delay: None
Frequency readout: None
Frequency response: N.A.
THD = N.A.
S/N = >100 dB
Gain = 0 dB
Size: 7.25 x 4.25 x 1.875 in. (185 x 108 x 48 mm)
Weight: 2.5 lbs. (1.1 Kg)
2. X-30 stereo, 2-way - 18 dB/octave
Price: $159
Note: This unit features line level inputs. Outputs are line level and
symmetrical about the chosen frequency.
Features: Frequency selection: 35 to 150 Hz, continuously variable.
Level: Individual per channel, 0 to +6 dB
Damping: None
Phase: Variable, 0-180 degrees
Summing (subwoofer) out: No
Time delay: None
Frequency readout: None
Frequency response: N.A.
THD = N.A.
S/N = >100 dB
Gain = 0 dB
Input impedance = Not stated
Output impedance = N.A.
Maximum input = Speaker level
Maximum output = N.A.
Size: 7.25 x 4.25 x 1.875 in. (185 x 108 x 48 mm)
Weight: 2.5 lbs. (1.1 Kg)
John Pomann's DIY active crossover kit:
Available directly from
John Pomann's web site.
1. Stereo 3-way, 24 dB/octave Linkwitz-Riley or 6 dB/octave Butterworth
(other configurations possible).
Price: $75 kit (standard), $85 (w. OPA2124 op amps), with power supply.
Features: Frequency selection: 50 steps from 42.1 to 9.175k Hz,
optional at assembly time.
Damping: None
Phase: Fixed
Time delay: None
Frequency response: DC - 100k Hz
THD = N.A.
S/N = N.A.
Gain = N.A.
Input impedance = N.A.
Output impedance = N.A.
Maximum input = N.A.
Maximum output = N.A.
Size: N.A.
Linkwitz transform equalizers:
The follwing equalizers implement a Linkwitz transform function, a
specialized form of bass boost which permits you to effectively change the Fb and
Qtc of a sealed speaker system.
Marchand:
Marchand sells most of their products asembled, as kits, or as EZ kits (most
of the hard work already done).
Marchand is available direct from Marchand or through numerous distributors.
1. WM8 stereo
Price: $249 kit, $299 EZ kit, $399 assembled
Features: Old Fb = 30 - 130 Hz
New Fb = 15 Hz, fixed
New Qtc = 0.25 - 1.0, variable
Filters: Rumble: Yes, defatable
HP: Yes @ 20 Hz, defatable
Frequency response: 2 Hz - 100 kHz
THD = <0.01%
S/N = >110 dB
Gain = 0 dB
Input impedance = 100 Kohm
Output impedance = 10 ohm
Maximum input = +/-12.5 V
Maximum output = +/-12.5 V
Size: 17 x 8.5 x 2.8 in. (432 x 216 x 71 mm)
Weight: N.A.
Filter modules:
Filter modules are the building blocks of electronic crossovers and
euqalizers. All of the following kits have been recommended. Listed
alphabetically by manufacturer.
Marchand:
Marchand sells most of their products asembled, as kits, or as EZ kits (most
of the hard work already done).
Marchand is available direct from Marchand or through numerous distributors.
1. XM1 - single channel, 24 dB/octave
Price: $25 kit, $30 assembled
Features: Frequency selection: 20 to 5k Hz, by plug-in module.
Damping: None
Phase: Variable, Fixed
Time delay: None
Frequency response: DC - 100k Hz
THD = <0.01%
S/N = >100 dB
Gain = 0 dB
Input impedance = 100 Kohm
Output impedance = 50 ohms
Maximum input = +/- 12.5 V.
Maximum output = +/- 12.5 V.
Power: +/- 15 VDC @ 50 mA.
Size: 2 x 3 x 1 in. (50.8 x 76.2 x 25.4 mm)
Instruments:
Various test and measurement instruments useful to the DIY'er are listed
alphabetically by manufacturer.
Parts Express:
Parts Expess sells directly via catalog and its web site.
1. The Woofer Tester - inlcudes a test box which attaces to a PC serial
port. Software included.
Price $250
Features: Measures driver Fs, Qms, Qes, Qts, Vas, BL, Re, Le, SPL@1W/!m,
Mmd, Cm, Rm.
Measures sealed box Fb and Qtc.
Meaures vented box Fc, ha, alpha, and Ql.
Also useful for meauring TL's and TQWT's.
©1998-2007 by Bob Stout, all rights reserved
Tested with:
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