FR-8X And The Bose L1 Pro8 – A Cable Lesson

[John M]

I recently purchased a Bose L1 Pro8 for use with my 8X. It has a great sound with the 8 treble speaker array and the 7” X 13” bass speaker that is powered by a 240 watt RMS bass amplifier.

I use a Bose T4S mixer with the Pro8. The Pro8 will power the Pro8 with Bose’s “special Tonematch Cable”. The Tonematch cable is 18 Ft. long and costs $55.00!. I didn’t want to have a separate power supply for the T4S, so I bought the cable. After looking closely at the cable connectors (which have protective shells over them), I realized the Tonematch Cable is nothing more than an Ethernet cable.

18 Ft. was way more than I needed, so I bought a shorter Ethernet cable for $3.00 and it works fine. Neutrik makes a special shell that can be attached to Ethernet cables that have the connectors all ready fastened to the cable ends. The Neutrik Part No. is NE8MC-B

Some of you may know that the Tonematch cable is a common Ethernet cable. The purpose of my post is for those of you that don’t know and a cheap Ethernet cable will do the job just fine.

 

[JerryPH]

To prevent external noise from getting in to the system, best to make sure to use CAT8 shielded ethernet cables.

 

[John M]

To prevent external noise from getting in to the system, best to make sure to use CAT8 shielded ethernet cables.

Good point Jerry. When using the T4S mixer to connect two Bose speakers in stereo, the audio communication to the speakers is all digital via the ethernet cables. Keeping out external noise is important and CAT8 shielded should be used. I used CAT6, which I think should be O.K. for my application, since the Pro8 is is only supplying +/- 18 VDC to the T4S mixer. I have the T4S right next to the Pro 8 connected with a 3 Ft. cable, so the distance is short. What an over kill for the 8 conductor ethernet cable. I think Bose saved a separate power input port, since the "Right" stereo digital output channel is also the input power (received from a model L1 power stand) for the T4S .

 

[Ventura]

actually, afaik, data is immune to picking up "noise" of the type that would be
drained with a shielded cable in an analog audio signal, and on normal
amp lines from the power amplifier to speaker, those are also immune.

if some kind of interference was able to alter/affect the data flow, it would simply
cause a data error, it could not re-write bytes to include new (suddenly noisy) data

the only possible thing you might add to improve the power over
ethernet system wires used to feed the DC current
would be an Inductor (loop) which helps keep the DC Voltage smooth
but i have never seen one used on an ethernet cable ever, but you can
salvage a carbon ring from something else and just loop the ethernet
cable through it twice if you want to

my personal issue would be with reliability, with the rather low robustness
of the Ethernet connector and clip, and the limited guage wire being used.
Except for the hassle with Warranty. i know i would just isolate the DC feed
and set up a separate dedicated and strong wire and connector system
of my own. Cat 8 is, after all, still 26 guage copper by spec, though some cat 6
ethernet cables have been made available with 24 guage, i doubt the connector
itself could handle anything thicker anyway

i like 18 guage when i build any power supply/feed that needs to run serious current
even momentarily, though 22 guage is most common in wall warts and such
up to 1 amp or so

for most people these differences are moot, but for you guys that Gig i know
you prize reliability highly, as we rely upon our equipment as our clients
rely upon us for our product. So for this reason i would recommend to hell
with the warranty and wire your own power transfer solution

 

[John M]

. . . my personal issue would be with reliability, with the rather low robustness
of the Ethernet connector and clip . . .

See attachment below of the housing mount I used for the Ethernet connector and clip. This is a very sturdy housing for protection of the connector. The Bose equipment has a socket that locks into the housing and holds it securely. The strain relief at the end of the housing grips the cable firmly. The Ethernet cable can be used without the housing, but the connector and cable is damaged more easily without the use of the housing.

 

[JerryPH]

See attachment below of the housing mount I used for the Ethernet connector and clip.

I've seen those before. If you take them apart, you will see they use CAT8 cabling with the metal edged sides that connect with the outer connector.