Shure ULX-D KSM9 sounds compressed

A

AJ Thomas

Freshman
Mar 17, 2014
1
0
0
Just wondering if anyone else has had any problems with the Shure ULX-D system sounding compressed.

We have a total of 12 channels using the Shure ULX-D quad range and are taking both analogue and Dante outputs from the recievers. The handheld transmitters are fitted with KSM9 capsules. Both in our analogue system and our digital recording system (running Reaper with Dante virtual soundcard) the signal from our radio microphones sounds compressed. It sounds compressed even when there is no processing at all on the channel and when it is below the peak level on the desk and recording.

Just wanting to see if anyone else is having this problem or if we've missed something in our setup.

thanks
AJ
 
Re: Shure ULX-D KSM9 sounds compressed

AJ Thomas said:
Just wondering if anyone else has had any problems with the Shure ULX-D system sounding compressed.

We have a total of 12 channels using the Shure ULX-D quad range and are taking both analogue and Dante outputs from the recievers. The handheld transmitters are fitted with KSM9 capsules. Both in our analogue system and our digital recording system (running Reaper with Dante virtual soundcard) the signal from our radio microphones sounds compressed. It sounds compressed even when there is no processing at all on the channel and when it is below the peak level on the desk and recording.

Just wanting to see if anyone else is having this problem or if we've missed something in our setup.

thanks
AJ
Click to expand...

Yes. I have noticed this on a large theater install. Body pack systems sounded compressed.

BTW, someone my pop up and say that it is a result of data compression. That is not the same thing and shouldn't affect that at all.
 
Re: Shure ULX-D KSM9 sounds compressed

AJ Thomas said:
Just wondering if anyone else has had any problems with the Shure ULX-D system sounding compressed.

We have a total of 12 channels using the Shure ULX-D quad range and are taking both analogue and Dante outputs from the recievers. The handheld transmitters are fitted with KSM9 capsules. Both in our analogue system and our digital recording system (running Reaper with Dante virtual soundcard) the signal from our radio microphones sounds compressed. It sounds compressed even when there is no processing at all on the channel and when it is below the peak level on the desk and recording.

Just wanting to see if anyone else is having this problem or if we've missed something in our setup.

thanks
AJ
Click to expand...

There still has to be an analog limiter before the AD stage in the transmitter, you're probably hitting it. Check your gain structure.

Sent from my SCH-I545
 
Re: Shure ULX-D KSM9 sounds compressed

I have been using ULXD beltpacks and handhelds with a variety of capsules daily for 2 years and have not noticed what you are experiencing.
Gary
 
Re: Shure ULX-D KSM9 sounds compressed

The max. bandwidth a radio mic can use is 200kHz. If you look into the different codecs (PSK, QPSK, APSK, FSK...) you will find out that it is not possible to transmit a 1156KB data stream into 200kHz (48kHz/24Bit A/D conversion) You need to reduce your data rate. As better your codec is, as better is the quality of your audio signal. But you have to take core for some more conditions. Good error correction means longer latency, bigger data rate means more signal noise ratio is needed, high quantity of simultaneous channels.... All parameters need to be in a good balance, Every manufacturer follow here his own philosophy. If you like to see why the system sounds compressed and why system with the double price not, measure frequency response, phase response, impuls response (example: 1kHz, 4kHz, 8kHz) and also the latency from 20Hz to 20kHz. You will truly see what you hear.
 
Re: Shure ULX-D KSM9 sounds compressed

IIRC, the system uses two separate gains to prevent the system from ever clipping, and granting a very large dynamic range. If you lower your gains a bit, you might find far more success in not reaching the upper end of that 120dB+ of dynamic range. Quick and simple test is to run a ramped signal through it and compare it to the initial signal. Quick smaart test would do it with a bodypack. The RF stage of the bodypack and the handheld are almost identical too, provided my memory is correct, so the test would cover that.

Also, I went back and read the post Rob linked by Langston Holland. He explicitly states in there that at -6dBu at the input side he started to see some limiting. For that reason, I would definitely suggest padding your input down a bit on the transmitter.
 
Last edited:
Top Bottom