• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Tafelberg

Member
Joined
Oct 18, 2022
Messages
17
Likes
9
I am setting up a Denon X3800h AVR (with Dirac Live Base Control), and 5.2.2 (5 ear level speakers, 2 subs, 2 ceiling speakers) configuration.

All the speakers are passive, except for the 2 subwoofers, and 2 JBL 306P MkII which will be placed at the Left and Right Surround Back positions.

The length of the wiring required to get from the AVR to the JBLs is approximately 25 feet.

What is the best way to connect the AVR to the 2 JBLs?

The 'headache' for me is that the Denon does not have balanced outputs, while the JBL has only balanced inputs.

I am considering using a 25 feet long RCA cable with one end connected to a Quarter Inch TS Mono Male to RCA Female Jack Plug, please see image below. The RCA end goes into the Denon pre-out output, and the TS plug goes into the TRS input on the JBL.

Will this work well? Is 25 feet too long for an RCA wire, will there be issues? Is there a better solution?

Thanks everyone!

1726659709704.png



1726659441453.png


1726658922131.png
 
It's possible that using that adapter, you will experience mains hum and other ground loop-related noises, as it negates the 306P's ability to filter out common mode noise.

To fix this, I would suggest you purchase a regular XLR cable, then modify (solder) one end to use RCA, just like ASR user @JeffGB did here:

Here's the resulting cable construction:
rca-xlr_corr (1).png2conductorsor3 (1).pngScreenshot 2023-11-23 at 08.38.00 (1).png
 
Last edited:
You can also use passive DI Boxes to convert the unbalanced pre-outs to balanced for the longer cable runs as @Blumlein 88 mentions here:

 
Hi

I used something similar for a long time:
71G0dEwX1ZL._AC_SX679_.jpg

available at Amazon for about $22 for 15 feet,
or you could make your own , as per @staticV3 post.


Peace.
 
As per the wiring diagram shown in the product pictures, that cable will defeat the XLR input's CMRR, making it more susceptible to common-mode noise:
View attachment 398563
Thanks!

I made my own subsequently based on ASR discussions on this very subject, just because, had some cables, from a studio project for a customer.
I hasten to say that , I had not experienced any issue with the previous cable.

I, however, strongly suggest to @Tafelberg to heed @staticV3 advice. Choose pre-made cables that follows the wiring schematics in post #2

Peace.

P.S. All my speakers are JBL Series 3, 308 for LCR, Surround (2) and Atmos (2) are LSR 305. I also use 2 subwoofers.
 
Back
Top Bottom