Turaco
Peerless 830883 with Seas 27TBCD/GB-DXT
15 Liters Bass Reflex
For years, I avoided this 830883 woofer because I really dislike her frequency response. I don’t know what the designers were thinking of when they did this woofer. Maybe it was specifically for one of their customers back in the Vifa days. When Tymphany came along, they probably inherited it. Nonetheless, since I already bought this woofer, I’ll see what I can make of it.
 Fig 1 – Peerless 830883 RAW (Black plot) • Blue plot with Low Pass filter
The success in working with the 830883 is in shaping the response that’s workable. After a few simulations, I decided on a crossover frequency of 1,500Hz. This suppresses the “ringing” seen from 1kHz ~ 3kHz (Fig 1). Furthermore, crossing at such a low frequency prevents the cone break-up from interfering with the tweeter.
 Fig 2 – Peerless 830883 Low Pass (Blue plot) • Seas 27TBCD/GB-DXT High Pass (Red plot)
For the tweeter, I chose the Seas 27TBCD/GB-DXT (Fig 2). As with the 830883, she is not an easy tweeter to work with. The main advantage I have is I can cross at my targeted frequency of 1.5kHz. As seen in the plot above, the two drivers are crossing acoustically at 1.5kHz.
 Fig 3 – Turaco Frequency Response
Fig 3 is the final frequency response of the Turaco. The midrange to the lower treble is virtually flat from 500Hz~3kHz. It’s quite remarkable that I’m able to achieve this considering the raw responses of the woofer and the tweeter.
 Fig 4 – Turaco with HiVi M8N-1B Subwoofer
In this Turaco, I didn’t install a Baffle Step Compensation network because the Sensitivity will be too low. This led to a bass response that’s somewhat lacking in volume. It will be louder in a smaller room but in my lab and in Free Space, the bass is not loud enough for most listeners. It is for this reason I decided to use my HiVi M8N-1B 8″ subwoofer. In Fig 4, the bass is so much stronger.
 Fig 5 – Turaco Waterfall
The Waterfall plot (Fig 5) shows minimal artifacts in the treble. There’s also not much energy from 1kHz~2kHz.
 Fig 6 – Turaco Spectrogram
Fig 6 is the Spectrogram. Whatever artifacts there are above 2kHz are fully dissipated by 2 msec. In the upper mids, that is between 1kHz~2kHz, there’s little green streaking. This indicates the vocals will not be “shouty”.
 Fig 7 – Turaco Step Response
The Turaco Step (Fig 7) is impressive. The 830883 exhibits a fast attack. In other words, she’s reacts very quickly. Her apex is sharp which means at the peak, she stops instantly. After that she decays linearly and quite quickly.
It is from this Step that we can see how tight drivers alignment is. The 830883 is only 204 microsec behind the DXT tweeter and that is with a crossover installed.
 Fig 8 – Turaco Harmonic Distortion
The Harmonic Distortion recorded no anomalies (Fig 8). The 2nd Harmonic is -47.0dB below the fundamental while THD (H2-H9) is -45.0dB.
Sound of Peerless 830883
The Peerless 830883 sounds very different from the other 6-1/2″ woofers from Peerless. Compared to my 830874, 835025 and the top of the line NE-180W-08, this 830883 bass has the least “weight”. I’m not referring to the loudness. Even if you EQ the bass up, it’s only in volume. Her bass still sounds “thin”. I don’t recall ever tested a woofer, particularly a 6-1/2″ with her bass is so anemic.
Sound of Turaco
I mated the 830883 with one of the best tweeters in my collection, the Seas 27TBCD/GB-DXT. This tweeter is exceptionally smooth. There’s no brightness and completely free of harshness.
Because of that, the midrange in the Turaco stands out. I do not mean vocals are “shouty” or over-emphasized. On the contrary, vocals sound “smooth”. Very “Hi-Fi” like.
Her midrange clarity is her greatest strength. I can hear the layering in the vocal harmony and instruments clearly. And there’s depth in the soundstage.
Summary
For the Turaco to impress, she needs to be played fairly loud. That’s where she shows her true colors. When at low volume, she sounds pretty ordinary.
Considering her bass weakness, I would still recommend the Turaco. One can easily overcome her bass deficiency by using a subwoofer.
Afterthought
Having worked on the 830883, I’m contemplating a 3-way project in future. That will solve the bass problem in the 830883.
I’m thinking of using the Peerless NE-180W-08 or an 8″ for bass. The 830883 will be in an internal sealed chamber strictly for midrange duty. For the treble, I’ll adopt the Wavecor TW030WA12 this time round. This is one tweeter that I can cross at 1.5kHz and yet sounds wonderful.
Unless otherwise stated, all measurements were made in Full Space (4pi). Mic at 36 ins, tweeter axis. Impulse Window=5ms. No smoothing applied. |
