Overview:
The HDS-P830875 is an 8Ω 6.5″ mid-woofer from the Peerless HDS series.
It uses a Nomex cone together with a concave dustcap. The 32.4mm voice-coil has an aluminium voice-coil former and it has a truncated chassi frame that allows for a narrower center to center spacing.
Key features:
- Nomex cone
- Powerful ferrite magnet system
- Linear spider design
- Rubber surround
- Aluminium shorting ring
- Long-throw voice coil
- Vented cone neck
- Air venting under the spider
- Cast aluminium basket
Peerless Spec sheet: HDS-P830875
T/S Parameters:
The T/S measurements are very close to the manufacturer’s specification.
Impedance:
(click on picture to zoom)
Minor differences between the two tested driver unit samples. Some wrinkles in the impedance plot can be seen around 1.1kHz, indicating some sort of resonance issue.
Frequency:
Frequency measurement conditions:
The mid-woofer is measured mounted on a baffle in an 19 liter closed enclosure with the following conditions:
Baffle size (WxH): 24×35cm with 18mm round-over on the baffle edges (r=18). No driver flushmount.
Driver position: Mounted on center-line with driver unit center 25,7cm from the top of the baffle.
Mic position: 1m distance, on mid-woofer-axis.
Smoothing: 1/24 octave smoothing applied.
(click on picture to zoom)
Left: Frequency response on-axis (Blue=sample#1 Red=sample#2).
Right: Frequency response 15deg off-axis (Blue=sample#1, Red=sample#2).
The two mid-woofer samples measures virtually the same.
0deg = Blue
15deg = Red
22.5deg = Green
30deg = Blue
45deg = Red
60deg = Green
Fairly smooth frequency response with a rising top-end response. There is a cone break-up around 4.9kHz, that might be needed to be notched out in the cross-over. The mid-woofer starts to roll-off at 2kHz and a good start for a x-over cross-over point would be somewhere around 1.8-2.2kHz.
Distortion:
Measurement setup:
- Mid-woofer near-field measurement at 15cm
- Frequency Range Mid-woofer: 200-10000Hz
- Baffle size WxH: 24×35cm. No driver flushmount.
The distortion measurements are done in near-field and the amplifier output level was adjusted for each driver so that the fundamental is 90dB and 95dB at 1m. This setting simulates medium-high and high listening levels.
(click on picture to zoom)
90dB @ 1m
Left = Sample #1
Right = Sample #2
(click on picture to zoom)
95dB @ 1m
Left = Sample #1
Right = Sample #2
The HDS-P830875 has an average distortion profile with a fairly high third-order distortion in the upper mids between 1-2.5kHz. By choosing a proper cross-over point, steep filter and by notching out the cone break-up, this shouldn’t be of a major concern.