The Grosbeak-XT is based on the 6-1/2″ Peerless 835025. I recently acquired this midwoofer when Parts-Express had a sale. I’ve never heard it before so this is a first. Based on the positive results from the Peerless 830874, I am hoping that this midwoofer will be even better.
Fig 1 – Peerless 835025 RAW Response • Baffle Width=8-1/2″
Fig 1 is the RAW response of the 835025. Readers that have been following my posts would recognize the similarity with the Dayton RS180s that I used in the Raven-XT2.
Fig 2 – Blue plot=835025 with Low Pass Filter
The Blue plot in Fig 2 is the 835025 with a 2nd order Low Pass Filter. I adjusted the crossover such that the peak at 7kHz is -20dB less than in the RAW response. It would not cause any issues because my intended crossover frequency is about 2kHz.
Fig 3 – Blue plot=Peerless 835025 with LPF • Peerless XT25TG30-04 with HPF
Fig 3 shows the 835025 crossing over to the XT25TG30-04 tweeter at about 1.8kHz. I normally do not cross this low with a HiFi tweeter but I don’t have much of a choice with the 835025.
Fig 4 – Grosbeak-XT Passband
The Black plot in Fig 4 is the crossover passband of the Grosbeak-XT. They appear to be summing properly as no cancellations are observed in the crossover region.
Fig 5 – Grosbeak-XT Frequency Response
The final Frequency Response of the Grosbeak-XT is in Fig 5. It looks encouraging. Nice and flat. I would not have been able to get this had I crossed the two drivers at 2.5kHz to 3kHz.
Fig 6 – Grosbeak-XT Null Response
Fig 6 is the Null Response when the tweeter wires are flipped. It is not as deep as I would like it to be but it’ll have to do for the time being.
Fig 7 – Grosbeak-XT Step Response
Fig 8 – Grosbeak-XT Waterfall
Fig 9 – Grosbeak-XT Toneburst Energy Storage
The Step Response (Fig 7) and the Waterfall plot (Fig 8) do not show any anomalies in the Grosbeak-XT. The Toneburst plot in Fig 9 shows some excess energy emitting from 1.5kHz but I doubt they are problematic.
Fig 10 – Grosbeak-XT Spectrogram
The Spectrogram shows slight excess energy at 1.1kHz and 1.3khz. They vanished by 6 msec. There’s a hot spot at 2.1kHz but it disappeared by 6 msec too.
Fig 11 – Grosbeak-XT Harmonic Distortion
The Grosbeak-XT 3rd harmonics (Violet plot) is impressively low at -60dB below the fundamental. The 2nd harmonics (Red plot) and the THD (Blue plot) are at -50dB.
Grosbeak-XT vs Cardinal-XT2
I was sorely disappointed when I auditioned the Grosbeak-XT. The Peerless 835025 is nothing like the 830874. It sounds more like the Dayton RS180s-8.
In fact, the Grosbeak-XT sounds very much like the Raven-XT2, perhaps with a bit more weight in the bass. It lacks the transparency and liveliness of the Cardinal-XT2. When you compare the two, it’s very obvious.
It doesn’t mean the Grosbeak-XT is a bad speaker. It’s just that I’m very critical. I like my speakers to sound like the Scanspeak 15WU that I used in the Enlightenment. That’s actually not a fair comparison because the 5″ 15WU cost more than $300 a piece. But it does give me something to strive for, unrealistic as it may be.
Crossover is available on request. Free for DIY. Not for Commercial use.