Cardinal-TA (Peerless 830874 with Seas 27TDFC)

PEERLESS 830874 SEAS 27TDFC

Cardinal-TA

The Cardinal-TA is a new addition to our Time-Aligned (TA) speakers. It is a compact 2-way bass reflex with an internal volume of 15 liters. Two outstanding drivers are used in this model, a Peerless 830874 and the Seas 27TDFC.

The 830874 is a 6.5″ mid-woofer with a Poly Cone. I was astounded when I first heard this woofer. The 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.

Peerless 830874 RAW Frequency Response

PEERLESS 830874 RAW RESPONSEFig 1 – Peerless 830874 RAW Response. Mic at 1 meter, tweeter axis, 1/12th octave smoothing

The Black plot in Fig 1 is the RAW response of the Peerless 830874 in a 15 liters box with a baffle width of 8.5″. Due to room limitations, measurements below 500Hz are Nearfield. The effects of Baffle Step can be clearly seen by the 6dB rise at 500Hz. Obviously, this needs attention otherwise the speaker will sound too bright and forward.

Crossing to the Seas 27TDFC tweeter

Peerless 830874 Low Pass and Seas 27TDFC High PassFig 2 – Peerless 830874 Low Pass and Seas 27TDFC High Pass Response

A woofer of this quality demands a tweeter better than the XT25TG30. Out came my favorite Seas 27TDFC. The Red plot in Fig 2 is the Seas tweeter whereas the Blue plot is of the Peerless 830874 woofer.

Cardinal-TA Frequency Response

CARDINAL-TA FREQUENCY RESPONSEFig 3 – Summed Response of Peerless 830874 and Seas 27TDFC

Fig 3 is the summed response of the Peerless 830874 and the Seas 27TDFC. No smoothing is applied from 500Hz onwards. Measurements below 500Hz are in Nearfield. In this frequency response, the Peerless and the Seas are time-aligned.

Time-Aligned Reversed Null Response

CARDINAL-TA REVERSED NULLFig 4 – RT1C wired in Reversed Phase

In Fig 4, the Violet plot is with the Seas 27TDFC wired in Reversed Phase. A very deep and sharp null can be seen. The 3kHz tip of the null is at -32dB below the fundamental. You will only get this kind of null when the two drivers are time-aligned.

the Sound of Cardinal-TA

Absolutely fantastic. This is the fastest, most realistic sound I’ve ever gotten. The designers of this Peerless 830874 got it spot on with this woofer. The Cardinal-TA is close to high-end sound but without the sky high cost. The only speakers I have that has this kind of sound quality is the Starling-II and Starling-TA which use 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 and box dimensions. For non-commercial use only.

Cardinal-TA by Frank Pronk
Feb 16, 2018

CARDINAL-TAMike,

With some reluctance, I disassembled my Cardinal-TA speakers so they could be properly finished.  They are now complete.  Attached is a picture.  Sound quality continues to amaze me given the modest cost of the drivers. The speaker enclosure turned out better than expected.  My table saw and router seemed to handle bamboo plywood quite well.

I am following your Falcon-II concept speaker with great interest.  I prefer speakers with a great mid-range.  This probably why I started
with full-range drivers such as the Alpair 6.2:  there’s no crossover so you can spend your limited speaker-building funds on just a good, single driver.  You won’t get much bass from an Alpair 6.2 though.  Your Falcon-II seems to have an outstanding mid-range and might soon be on the top of my project list.

Frank