master_fo
Active Member
Here, sharing my positive experience modifying Emerald Physics EP4.7 speakers!
Compression drivers: removed bug screens (not needed because of dust caps). Measurable improvement in 10-20K distortion (2-3 dB less), more 'silky' sound, does not really increase SPL. Dynamat on the back.
Woofers: Dynamat around steel cast baskets and magnets + felt on inner basket beams
Crossovers:
- Separated bass section of the crossover and added binding posts for bi-amping - great result with Yamaha CR-2040 on bass and custom 6L6 tube amp on main. Even better results with a single tube amp, driving bass from 0-4 Ohm output transformer terminals, and mid/hi from 8-16 Ohm (0.6 voltage -> ~ -3 dB)
- After extensive REW sessions, figured woofer phase response matched mid-woofer when inverted(see the pic) and speakers do sound better as well.
- Increased low-pass filter cap to 160uF and its resistor to 2Ohm
- Removed both 12Ohm and 22Ohm shunts in mid and tweeter filter sections
- Changed other resistor values to adjust for removed shunts
- Installed 2 LPADs to adjust treble volume and compression driver EQ level. It seems like a bit higher value than the original 1.8Ohms yields more linear response (about 3Ohms).
- Added wood side panels.
Pics attached.
Compression drivers: removed bug screens (not needed because of dust caps). Measurable improvement in 10-20K distortion (2-3 dB less), more 'silky' sound, does not really increase SPL. Dynamat on the back.
Woofers: Dynamat around steel cast baskets and magnets + felt on inner basket beams
Crossovers:
- Separated bass section of the crossover and added binding posts for bi-amping - great result with Yamaha CR-2040 on bass and custom 6L6 tube amp on main. Even better results with a single tube amp, driving bass from 0-4 Ohm output transformer terminals, and mid/hi from 8-16 Ohm (0.6 voltage -> ~ -3 dB)
- After extensive REW sessions, figured woofer phase response matched mid-woofer when inverted(see the pic) and speakers do sound better as well.
- Increased low-pass filter cap to 160uF and its resistor to 2Ohm
- Removed both 12Ohm and 22Ohm shunts in mid and tweeter filter sections
- Changed other resistor values to adjust for removed shunts
- Installed 2 LPADs to adjust treble volume and compression driver EQ level. It seems like a bit higher value than the original 1.8Ohms yields more linear response (about 3Ohms).
- Added wood side panels.
Pics attached.
