A Problem With REL’s Neutrik Speakon Subwoofer Connector System

REL subwoofers have a unique connection system that they call Neutrik Speakon. It is advertised as, “This has the advantage of ensuring that the REL receives exactly the same signal as the main speakers. This means that the character of the bass from the main system is carried forward into the Sub-Bass System. This is a very important point and together with the REL’s Active Bass Controller (ABC), ensures superior system integration of the Sub-Bass System with the main system.” While it is true that this type of connection will not interfere with the signal going to the main speakers I have found that this type of connection is not a superior way to integrate a sub-bass system with the main system.

The problem is that you will almost always get elevated bass response where the sub-bass system and the main speakers overlap in response. I find this problem to exist in every REL setup that uses a Neutrik connector that I have encountered. This is caused by the additive effect of the the two systems. Other methods use a combination of low and high pass filters to avoid the problem. This type of connection is also found on the REL subwoofers which is the proper way to integrate a subwoofer into a stereo system. The following is an illustration of the Neutrik connector.


REL Neutrik Speakon Connection Diagram

To summarize, I recommend avoiding the Neutrik connector system found in REL subwoofers. I would either use the bass management found in a surround processor or the high and low pass filter system found in the REL subwoofer itself.

W. Jeff Meier

ISF and THX Certified Home Theater Consultant


Just curious…how do you know that the elevated response is due to the connector and not something else, like the room?

W. Jeff Meier

Because when you connect the subwoofer properly it goes away. It also always occurs around the crossover point of the subwoofer as expected.

There are also technical reasons that this is guaranteed to occur, but I was trying to keep this post less technical since results are really all that matter. It should also be obvious since no one else is recommending this practice. Take a look at page 18 of Revel’s B15a manual . It discusses many connection options including this type and “strongly” recommends not doing this for these reasons.


Hi Jeff,

I have an MJ Acoustics sub that uses a speakon connector like the REL’s. The sub has 2 xovers. One for the left and right or LFE lo inputs and one for the speakon hi input. It’s connected to my receiver using the LFE lo input and the speakon hi input together. If I disconnect the speakon connector as you suggest how will I incorporate bass into my system when the source does not have a dedicated low frequency channel?


If you read the manual from Rel you’ll find that the Neutrik connector is the preferred way, and if you read further, you’ll even find -how- you can use the additive effect to your advantage.
My main speakers have a low frequency of 50Hz @ -3dB, I have my Rel setup with a crossover at 24Hz.
The net effect is that the Rel will still respond above 24Hz, but the output will decrease slowly with rising frequencies. The same, but opposite effect is true for the main speakers; they will continue below 50Hz, but bring less and less to the party with decreasing frequencies.
The net effect is that I have a near flat response from 20Hz upwards.

I have had a friend, who also owns a Rel, and on another occasion a dealer who helped me installing my speakers, reconfigure the sub from scratch, and we all ended up with the same crossover frequency and volume settings.

For movies I use the LFE connector and the Rel will happily work with both connectors at the same time; extending the main speakers into very-full-size and giving a very good grunt with LFE effects.

My rel is by far the cheapest component in my setup, and I wouldn’t trade it for a non-neutrik variety.

W. Jeff Meier

I have read the manual and following it will lead to sub optimal low frequency response in virtually all cases.


Nice article, i have REL T1 and Int Amp Rega Elex-R, what the best connecting for maximal result? I am very happy with diagram. Thanks

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