Got a question you'd like to ask?
Subscribe to the Radial newsletter

ProMS2™ FAQ


Why are mic splitters always mic level?

Since the source is usually a microphone or a direct box, most splitters used in professional touring are mic level. By maintaining all signal levels at the same relative loudness, there is less risk of introducing distortion and crosstalk into the PA system.

Why is the pad set at -30dB?

Most microphones produce output levels that are about -40dB below a +4dB line level source. To protect the ProMS2 from overload, a -30dB pad works well with most high output instruments.

Will 48V phantom power hurt the ProMS2?

No. Phantom power will simply not pass through the isolation transformer. Make sure the ground is lifted on the AUX out if you are feeding a mixer. This will prevent 48V phantom from this mixer colliding with the 48V from the FOH mixer.

Does the ProMS2 require power?

No. The ProMS2 is a completely passive device that does not require any power to work. Just plug in and play.

What is the difference between the Radial ProMS2 and the JS2?

The only difference is the transformer. This results in a slightly narrower frequency response at the top end, above 15 kHz. The feature set and internal circuit are the same.

Can I use the ProMS2 to stop buzz and hum between two consoles?

You could but this is not ideal. The Radial Twin-Iso is specifically designed to do this as it has larger line-level transformers for this purpose. In a pinch, the ProMS2 will work - however you will want to make sure the signal going into it is no more than about 0dB in order to avoid distortion.

Can I use the ProMS2 to split a keyboard or CD player signal and drive two sources?

Yes. Keep in mind that you will have to use a ¼" to XLR adaptor cable as the inputs and outputs on the ProMS2 are all XLRs. You may also have to engage the pad as some keyboards produce a high level output that could overload the transformer.

Can I send the output from the ProMS2 directly to a recording system?

It depends. The ProMS2 is a mic level splitter, designed to connect a mic preamp such as found on a mixer's microphone input. If your recorder also features a built-in mixer you should be ok. If it is a line level device, then you will require a mic preamp or mixing console to boost the signal.

Can I rack mount the ProMS2?

Yes. There are two rackmount options available: The J-Rak 4 and the J-Rak 8.

What is a ground loop?

A ground loop is formed when the earth (electrical ground) and the audio ground are at odds with each other. This is often caused by voltage differentials between the various pieces of equipment being connected together. Transformers help by blocking stray DC voltage which can cause noise. Ground lift switches are also used to assist in keeping the PA system as quiet as possible.

Can I use the ProMS2 with a high impedance, unbalanced consumer-grade microphone.

You can, but the results may not be ideal. The ProMS2 is designed for low impedance, balanced microphone level splitting.

How to I wire the XLR cable if I am using an unbalanced microphone with the ProMS2?

The XLR cable should have pins 1&3 tied together. You should also keep the XLR cable from the microphone to the ProMS2 under 20ft to reduce the potential of unwanted noise.

What is the difference between the JS2 and the ProMS2?

The primary difference is the transformer. In the JS2 is a Jensen. This delivers unmatched frequency response and because of the dual Faraday shield design, it will also exhibit less noise. The JS2 is a good as it gets . while the ProMS2 does a spectacular job at a more affordable price.