The Cardinal is based on one of my favorite midwoofers, the Peerless 830874. I first tried it with a PRV D280iTi compression driver coupled to a Dayton H07E horn. After that, I did two versions with with dome tweeters, a Seas 27TDFC and the aluminum diaphragm 27TBFC. In this fourth design, the 830874 is mated with the Peerless XT25TG30-04 tweeter.
Fig 1 – Peerless 830874 RAW Response • Baffle Width=8-1/2″
The Peerless 830874 frequency response is a delight to work with (Fig 1). It has a smooth and flat response with desirable extension to 4kHz, after which it rolls off gently. Nothing like the Dayton RS180s-08.
Fig 2 – Blue plot=Peerless 830874 with LPF • Peerless XT25TG30-04 with HPF
The Blue plot in Fig 2 is the 830874 with a basic 2nd order Low Pass Filter (LPF). The Red plot is the XT25TG30 also with a 2nd order High Pass Filter (HPF).
Fig 3 – Cardinal-XT2 Passband
The Cardinal-XT2 crossover passband is the Black plot in Fig 3. I’m encouraged to see there are no cancellations in the crossover region. That’s always a good sign.
Fig 4 – Cardinal-XT2 Frequency Response
The Cardinal_XT2 Frequency Response is in Fig 4. It is not as flat as in the Raven-XT2 but it’s perfectly acceptable. What is more important is the sound quality.
Fig 5 – Cardinal-XT2 Null Response
Fig 5 is the Null Response of the Cardinal-XT2. Though the depth of the notch is not -40dB deep, it does show the alignment of the two drivers are quite close. I’m reluctant to tamper with the cross to get a deeper null because it often throws everything off.
Fig 6 – Cardinal-XT2 Step Response
The Step Response in Fig 6 took me by surprise. The 830874 is actually a tad slower than the RS180s. The apex is at 500 microsec whereas the other midwoofers are at 400 microsec.
Fig 7 – Cardinal-XT2 Waterfall
The Waterfall plot in Fig 7 shows no anomalies in the treble.
Fig 8 – Cardinal-XT2 Toneburst Energy Storage
The Toneburst plot in Fig 8 doesn’t register any stored energy at 1kHz. All the excess energy are above 2kHz.
Fig 9 – Cardinal-XT2 Spectrogram
The Spectrogram in Fig 9 shows a very well behaved Cardinal-XT2. There’s some stored energy at 1.2kHz and 2.1kHz but they soon disappear by 5 msec.
Fig 10 – Cardinal-XT2 In-Room Response
The Black plot below 500Hz is my In-Room response. What this means is that they include reflections in my room. Disregard the deep notch at 150Hz. That’s caused by a floor bounce in my setup.
The area of interest is from 100Hz to 65Hz. We can see the bass is almost level with the midrange. This measurement was taken with the Cardinal-XT2 in full Space (4 pi). In a smaller room or placed nearer to a back wall, the bass will be stronger.
Sound of Cardinal-XT2
It has been such a long time since I last heard the Peerless 830874. Now that I worked with all the other midwoofers consecutively, it’s apparent the 830874 is in a class of her own. The clarity in the vocals is crystal clear. On top of that, I can make out the layers in the soundstage, where the backup singers are etc. As for the bass, it was an eye opener. There’s upper bass, lower bass and excellent dynamics. No bloated bass, no bloom in the bass notes. This kind of quality is normally found in more expensive drivers like the Seas ER18RNX which cost double that of the 830874.
The Cardinal-XT2 is my kind of speakers. This is how I like my music to sound like. For those contemplating which model to build, I strongly suggest the Cardinal-XT2. She is near high-end level.
Unless otherwise stated, all measurements were made with the mic at 36 ins, tweeter axis. Impulse Window=5ms. No smoothing applied.
December 1, 2020HIFI DRIVERS, Projects