Total posts : 45366
The Eclipse 4000, was made by HLLY a Chinese company famous for poor audio quality, high spurious emissions, poor harmonic filtering and being off frequency. We have a warning about these transmitters on our website; MobileBlackBox simply changed the color of the case and stuck their name on the HLLY transmitter.
Being off frequency could be a problem, check to see if the effect is as audible on analog dials.
Even with a high quality transmitter like an EDM LCD transmitter, improperly equalized audio can wreck havoc on the transmitted audio; with the type of distortion you describe. With a mixer and a equalizer, making the audio acceptable for broadcast can be a challenge and still have it sound right. I would put an audio processor like the Behringer DSP 1425P between your audio source and the transmitter, starting with an audio level of -10db. Short of that, see if your audio card has an EQ on it; if so, pull anything above 15k to the minimum setting. We have to do that with some of our feeds to make it acceptable for broadcast. You should also check the audio level to the transmitter, it may still be overdriving it.
I just had to deal with this problem with one of our FM stations, all the meter levels were correct, the EQ was set right; yet we were still getting that high end clipping. Turns out the Audio Master processor’s meter feeding the compressor was set to +8db scale, so when the meter was reading 0db it was really +8db and slamming the processors front end; causing the clipping. Because of that switch, all the levels looked normal yet were killing our audio with high end distortion.
All transmitters I have used over the decades except the EDM’s have needed an equalizer to clean up the audio. The EDM LCD is the only transmitter you can run bare bones and still have it sound outstanding on the air.
Since you really have an HLLY under the hood; one of the many names the Chinese company uses, and live in a condo, you might want to make sure it’s not trashing nearby radios & televisions with its poor harmonics and spurs.
I noticed HLLY is gone from E-bay, could be to many make goods for Paypal, here is a link to the company that made your transmitter, it now has a new name: http://www.vhf-fm-transmitter.com
While the EDM LED may not look as cool as the HLLY; it walks circles around it in terms of audio & RF performance and the price is about the same.