Category: ‘Blog’

Hulgich Audio Duke Loudspeaker reviews!

September 28, 2019 Posted by gornir

 

The Hulgich Audio review section is updated with three new loudspeaker reviews of the Hulgich Audio Duke loudspeaker.

Read more about it here:

Hulgich Audio reviews

Or visit the reviews directly from here:

Soundstage Australia – Hulgich Audio Duke Loudspeaker Editor’s follow-up review

Soundstage Australia – Hulgich Audio Duke review

Headphone & Earphone Reviews – Hulgich Audio Duke review

Stereonet Forum – Hulgich Audio Duke review

 

SB17NBAC35-4 vs SB17NAC35-4

March 9, 2019 Posted by gornir

(Click on picture to zoom)

This short blog post describes the difference between the SB Acoustics SB17NBAC35-4 and the SB17NAC35-4 mid-woofers. In the picture above you can see the NBAC driver to left and the NAC driver to the right. The only visible difference is the color of the aluminium cone.

The questions are — Do they measure the same and is the only difference the color of the cone? I will try to answer this by providing some measurements below.

T/S Parameters:

 

(Click on picture to zoom)

Top: SB17NBAC35-4 vs. SB17NAC35-4 T/S parameters measured using “added” mass method in horizontal position.

Bottom: SB17NBAC35-4 vs. SB17NAC35-4 T/S parameters measured using “known” mass method in vertical position.

According to the official specification sheets there are some small difference between the two versions. The measured T/S parameters also show small differences, but in reality it could be the variations between different production batches.

Impedance:

 

(click on picture to zoom)

Left: Free-air impedance. NBAC vs. NAC.
Right: Close-up of free-air impedance. NBAC vs. NAC.

The impedance plot is similar between the two versions. The cone break-up is slightly higher up frequency for the NAC version, 10kHz vs 9.7kHz for the NBAC version.

Frequency:

 

Frequency measurement conditions:

The mid-woofer is measured mounted on a baffle in an 17.6 liter closed enclosure with the following conditions:

Baffle size (WxH): 20×40cm. No baffle edge round-over.
Driver position: Mounted on center-line with driver unit center 17cm from the bottom of the baffle.
Mic position: 1m distance, on mid-woofer-axis.
Smoothing: No smoothing applied. Measurement valid down to 275Hz.

(click on picture to zoom)

Left: Frequency response on-axis. NBAC vs. NAC.
Right: Frequency response 15deg off-axis. NBAC vs. NAC.

Virtually the same frequency response. The slightly different cone break-up mode is visible around 9.7-10kHz.

Distortion:

 

Measurement setup:

  • Mid-woofer near-field measurement at 18cm
  • Frequency Range Mid-woofer: 200-10000Hz
  • Baffle size WxH: 20×40cm

 

The distortion measurement shown is done in near-field and the amplifier output level was adjusted so that the fundamental is 95dB at 1m. This setting simulates a high listening level.

(click on picture to zoom)

Left: = SB17NBAC35-4 — 95dB @ 1m

Right: = SB17NAC35-4 — 95dB @ 1m

Both versions are very low distorting drivers.

Conclusion:

 

The NBAC and NAC versions are very similar in measurements and they are they interchangeable of each other in the same cross-over design. The small differences shown above are most likely caused by measuring different production batches. In fact there are a couple of years between the production of the above mid-woofers, so consistency seems to be good between production batches.

The only real difference between the two versions is the color — Pick your favorite color and looks!

For further measurement details of the two versions, see: SBAcoustics SB17NBAC35-4 and SBAcoustics SB17NACC35-4.

SB Acoustics SB17NBAC35 Measurements!

March 9, 2019 Posted by gornir

On the test bench we have the SB17NBAC35-4 and the the SB17NBAC35-8 6″ mid-woofers from SBAcoustics.

For further details see: SBAcoustics SB17NBAC35-4 and SBAcoustics SB17NBAC35-8

 

Hifi Show Report!

February 19, 2019 Posted by gornir

Hi everyone,

Here are some pictures and comments from the HighEnd Hifi show I visited 16-17th of February 2019 here in Stockholm, Sweden.

Stockholm High End 2019

SB Acoustics SB17NRX2C35-8 Measurements!

February 6, 2019 Posted by gornir

On the test bench we have the SB17NRX2C35-8 6″ mid-woofer from SBAcoustics.

Note! This driver replaces the discontinued SBAcoustics SB17NRXC35-8 loudspeaker driver.

For further details see: SBAcoustics SB17NRX2C35-8

 

SB17NRX2C35-4 vs SB17NRXC35-4

December 26, 2018 Posted by gornir

(Click on picture to zoom)

This short blog post describes the difference between the discontinued SB Acoustics SB17NRXC35-4 loudspeaker driver and its replacement SB17NRX2C35-4. In the two pictures above you can see the old NRX driver to left and the new NRX2 driver to the right. The only visible difference is that the new NRX2 driver has a larger dust cap and the label on the backside of the magnet is different.

The questions are — Do they measure the same and is the new NRX2 driver a drop-in replacement for the old NRX driver? I will try to answer this by providing some measurements and a simple cross-over simulation below.

T/S Parameters:

 

(Click on picture to zoom)

Left: SB17NRXC35-4 T/S parameters measured using “added” mass method in horizontal position.

Right: SB17NRX2C35-4 T/S parameters measured using “added” mass method in horizontal position.

According to the official specification sheets, the old NRX diver should have about 2dB higher sensitivity, but in real life they have just about the same sensitivity as the new NRX2 drivers.

Impedance:

 

(click on picture to zoom)

Left: Free-air impedance. NRX vs. NRX2.
Right: Close-up of free-air impedance. NRX vs. NRX2.

The impedance plot is similar between the two versions, but there are some variation between 08-2kHz and for the NRX2 version the impedance plot shows a small wrinkle around 6.1 kHz, where the cone break-up is.

Frequency:

 

Frequency measurement conditions:

The mid-woofer is measured mounted on a baffle in an 17.6 liter closed enclosure with the following conditions:

Baffle size (WxH): 20×40cm. No baffle edge round-over.
Driver position: Mounted on center-line with driver unit center 17cm from the bottom of the baffle.
Mic position: 1m distance, on mid-woofer-axis.
Smoothing: No smoothing applied. Measurement valid down to 275Hz.

(click on picture to zoom)

Left: Frequency response on-axis. NRX vs. NRX2.
Right: Frequency response 15deg off-axis. NRX vs. NRX2.

The new NRX2 version has a smoother frequency response between 0.8-4kHz, but on the other hand more pronounced break-up modes between 4-8kHz compared to the old NRX version.

Distortion:

 

Measurement setup:

  • Mid-woofer near-field measurement at 18cm
  • Frequency Range Mid-woofer: 200-10000Hz
  • Baffle size WxH: 20×40cm

 

The distortion measurement shown is done in near-field and the amplifier output level was adjusted so that the fundamental is 95dB at 1m. This setting simulates a high listening level.

(click on picture to zoom)

Left: = SB17NRXC35-4 — 95dB @ 1m

Right: = SB17NRX2C35-4 — 95dB @ 1m

Both the new NRX2 and the old NRX are low distorting loudspeaker drivers, but there are some differences due to different cone edge resonances and cone break-up modes.

Cross-over simulation:

 

(click on picture to zoom)

The cross-over simulation shows a simple electrical third-order cross-over with an acoustical fourth-order Linkwitz-Riley cross-over topology. As can be seen by the frequency plot the NRX2 has a smoother response, but the cone break-up modes are less suppressed compared to the old NRX version using the same cross-over.

Conclusion:

 

The two NRX versions are similar in many aspects, but are they interchangeable of each other in the same cross-over design?

Maybe, but some fine tuning might be necessary depending on the cross-over design. Also, another factor to consider is that if combining the two NRX versions with the same tweeter, the drivers relative acosutical off-set is about 3-4mm larger using the new NRX2 driver compared to the old NRX driver.

For further measurement details of the two NRX versions, see: SBAcoustics SB17NRXC35-4 and SBAcoustics SB17NRX2C35-4.

SB Acoustics SB17NRX2C35-4 Measurements!

December 25, 2018 Posted by gornir

On the test bench we have the SB17NRX2C35-4 6″ mid-woofer from SBAcoustics.

Note! This driver replaces the discontinued SBAcoustics SB17NRXC35-4 loudspeaker driver.

For further details see: SBAcoustics SB17NRX2C35-4

 

SB Acoustics SB17NRXC35-4 Measurements!

December 25, 2018 Posted by gornir

On the test bench we have the SB17NRXC35-4 6″ mid-woofer from SBAcoustics.

Note! This driver has been discontinued, but can be found second hand and is still available at some shops!

For further details see: SBAcoustics SB17NRXC35-4

 

SB Acoustics Satori MW16P-8 Measurements!

November 18, 2018 Posted by gornir

On the test bench we have the Satori MW16P-8 6.5″ mid-woofer from SBAcoustics. This is a very nice performing mid-woofer

For further details see: SBAcoustics Satori MW16P-8

 

Driver Measurement Methods!

November 17, 2018 Posted by gornir

 

Hi everyone,

From now on when I publish loudspeaker driver measurements, I will present it slightly different than before!

First of all I will visually present the frequency measurements and impedance differently. In the past I’ve used screen shots from the Holm Impulse and DATSv2 software, but in the future I will use LspCAD 6 Pro to visually present the frequency graphs. In that way I can e.g. show all measurements between 0 and 60 degrees in one graph. Below is an example how it will look like.

(click on picture to zoom)

Secondly I will present and measure the Thiele Small measurements slightly different for all mid-woofers and woofers. All drivers will be burnt in for 3 hours at their resonance frequency and slightly below the x-max excursion limit of the driver. After the driver has cooled off, it’s measured in two ways.

First the driver will be measured using the “added” mass method in a horizontal position. Secondly the driver is measured using the “known” mass method in a vertical position. In this case the “known” mass is the Manufacturer’s specified Mms of the driver unit.

The driver units are always measured in pairs or more and the individual driver samples measurements will be presented as well as the average of the two drivers.

Regards

/Göran