mDm mp3 plays audio to loud through fm transmitter

[maxall777]

Hi has anyone had the same problem as I have my mp3 player plays songs to loud through my FM transmitter. If I play them through my pc and then to the FM transmitter it is ok because I am able to turn volume down on my pc.but I can not do this with my mp3 player because there is no volume control.

[Dan Lott]

Try this see if it works..



http://lightorama.mywowbb.com/view_topic.php?id=19944&forum_id=74&highlight=mp3+volume+to+loud


This possibly could lower the level of your music then load on sd card. there also is another post that i remeber within the past month that explained it for the mp3 box set up.

[maxall777]

Thanks alot I will try this.

[Tim Fischer]

What transmitter are you using? Some of them have adjustable line levels...

[Surfing4Dough]

Had the exact same thing happen, until I today emailed EDM (my transmitter maker) to see if they had any insight. Though I ultimately fixed it myself, they had some tips to help make sure nothing else was wrong. First the short description of the fix--buy a "In-line volume control headphone adapter" (http://www.radioshack.com/product/index.jsp?productId=2552561) -- 10 bucks at The Shack, in the iPod type section. I backed the volume way down, and it seems to sound great now. I think the line-out on the mini-director is too loud, and over powers the transmitter. I plugged headphones directly into the mini-director, and the audio was very loud, so I then inserted the volume control adapter and plugged the headphones into that and adjusted the volume to a comfortable listening level. That is the level that seemed to transmit well.

Now the longer discussion with EDM, since you might want to test some things to make sure you don't damage your equipment. Below is a transcript of our emails back and forth--mine in red, theirs in green. Sorry for the long post, but I found some of their tips useful and figured others might. Surprised this hasn't come up before on these forums.

I recently purchased an EDM-LCD-RDS-EP from you, and for the most part I am very pleased. Assembly was very easy. I am using this for a Christmas light display, using Light-o-rama (LOR). The audio for my show comes from this mp3 mini-director unit (http://www.lightorama.com/Documents/mDM_MP3.pdf), which supplies "line-level output." Only issue is that it seems like the bass on all my songs is very strong and causes the car speakers to "rattle" at several points in songs, maybe even "distorted", even if the bass settings of the receiving car radio are turned down. Note, when playing this mp3 on my computer through my computer speakers, even pretty loud, it doesn't do this, and I have cheap computer speakers. Not sure if I need to adjust a setting on the transmitter, or in the instruction guide you mention using a "MP3 to RCA line-level attenuator" (and to contact you for help on this--hence this email). Not sure if this is even what this is talking about, or exactly what that is. Can you provide any guidance with regards to this? I searched the posts in the EDM yahoo group, but not sure if their discussions regarding attenuators is the same issue I am having or not. Is something like this of any use? For what it is worth, I am just using the EDM test line antenna.


The transmitter will respond down to 20Hz which is a low frequency and can cause problems for small speakers.

What happens when you play from your computer direct to the transmitter, bypassing the LOR MP3 unit?

What we can suggest is that you use the equalizer that come with most PC based players and progressively pull down all frequencies below 150Hz until you eliminate this bass-boost effect that you experiencing. This may give you an idea of how much equalizing are needed

If you are not playing from a PC you may need to tailor your response in a program like Adobe Soundbooth or a similar type of audio processing program to reduce the low end response before saving it to a memory card.

You may find this free tool handy http://www.stereotool.com/

We have not received any other complaints about this issue. There are no adjustments on the transmitter other than audio levels, but it will not affect frequency response.

Please keep us informed about your findings. Regards, EDM Sales


An update...

It appears that it has something to do with the LOR mp3 unit, since it doesn't do it when transmitted from the PC. I also noticed though that the mp3 unit played the music MUCH louder than the pc. I tested the pc first and the sound was great (distortion and volume) and then I plugged in the mp3 unit and it was much louder and I had to turn down the car volume setting a lot (nearly half). Listening closer, it seems like it distorts not just with the bass, but anything that is louder in the song. I wonder if the LOR mp3 unit input is too strong. I might try the in-line volume control switch (http://www.radioshack.com/product/index.jsp?productId=2552561) to see if this helps back down the overpowering input and improves. If that doesn't work, I will have to try the audio processing program route. I agree this has nothing to do with your product, and I appreciate your help. Please feel free to add any other insight you have on this if you think I might be missing something.


Maybe the LOR unit’s output is not a true line-level output but at a much higher level.

If the input to the EDM is too high the internal limiter will be activated (to protect the unit) which will result in clipping of the audio, hence distortion.

Try the LED audio-level test as indicated in your EDM manual to see if the audio level is too high. (This tool description is attached to this post.)

Regards, EDM Sales


For your reference, the "In line volume control headphone adapter" fixed my problem. I backed the volume way down, and it seems great. If this seems to work, there isn't any problem with this correct?

By the way the 1.8V Red LED didn't light either way (with or without the volume control adapter).


Glad you fixed it. When the LED lights almost constantly that will indicate that the input adjustments of the EDM will have to be set very low to prevent distortion. It is possible that the LED will only light on short peaks in the music that exceeds the max allowable level.










Attached files Line level tool[1].pdf

[maxall777]

Thanks alot for the long post I will also try the inline volume control.