|Peerless PPB 830874 Poly Cone 6.5″ Woofer
I was astounded when I first heard this woofer. Bass is superb. Full of detail. It has a very fast attack with fantastic damping. Mid-range is crystal clear, close to my cherished Carbon Fiber Audax HM130CO. I never expected a Peerless to sound so good. I was sorely disappointed with my 8″ Nomex 830869 so this came as a huge surprise.
Cardinal-II Frequency Response
A woofer of this quality demands a tweeter better than the XT25TG30. Out came my favorite Seas 27TDFC. The Red plot in Fig 1 is the Seas tweeter whereas the Blue plot is of the Peerless 830874 woofer. The Black plot is the summed response of the two drivers.
Fig 2 is the response with the Seas 27TDFC wired in Reversed Phase. The notch is not very pretty but it does indicate that acoustically, the two drivers are crossing at about 3kHz.
Cardinal-II Frequency Response with Nearfield Measurements below 400Hz
In Fig 3, measurements below 400Hz are taken with the microphone less than 1/4″ away from the surface of the woofer cone. This is know as nearfield measurements. As can be seen, there is no deep notch at 150Hz, confirming that it is an anomaly caused by a sound wave bouncing off the floor. This only happens when the speaker is 1 meter above the ground and the mic 1 meter away. It is one of the quirks of my room.
Cardinal-II Harmonic Distortion
2nd and 3rd Harmonic Distortion in Fig 4 are -50dB below the fundamental. No high distortion is recorded, indicating the drivers are working properly.
|Cardinal-II Sound Quality
Absolutely fantastic. This is the fastest, most realistic sound I’ve ever gotten. The designers of this Peerless 830874 hit it spot on with this woofer. The Cardinal-II is close to high-end sound but without the sky high cost. The only speaker I have that has this kind of sound quality is the Starling which uses a Seas ER18RNX that cost double the 830874.
Crossover Values & Box Dimensions
If you’re interested to build this project, kindly send me a mail for the crossover component values and box dimensions.
October 11, 2017Projects