Guy's
Has anyone been able to quite down the "Sounder" sound decoder from MRC? Even after setting all sounds to zero they are still too loud, at least to me. This is especially true when using the "Sounder" with improved speakers.
Is there an electronics wizard among us who can provide guidence on a fix for this?
Thanks, Chris
Chris,
The only thing I have been able to do is turn the tunable pot on the decoder. Look for a silver disc with a slot for a very small screw driver. With the system on the track, turn the pot until the sound is reduced.
Good luck
Bob.
Bob,
Thanks, it looks like some MRC decoders have this pot. My Athearn Genesis F-3 for example has it. The "Sounder" does not. I was wondering if one of our electronics guy's would know how to put a pot in series with the speaker, maybe with a capacitor.
I was wondering about the same thing. I think you would just install the pot in a speaker wire.
Maybe.
Rotor
Jake: How often does the train go by? Elwood: So often you won't even notice ...
I temporarily got around it by replacing the 1" speaker with a 1/2" one with enclosure. (This is in the B unit of an A-B FT set.) I may end up moving this one into a narrow-bodied road or switching diesel where I'd only use a 1/2" speaker anyway...but I'm surprised they don't have some way to control the sound better.
(For those that don't have a sounder, the volume control CV only gives you the choices of 0,1,2 and 3. As best I can tell, 0 is about 50-60% full volume, which is maybe twice as loud as a Soundtraxx decoder at full power. 3 is about as loud as a real engine!! The sound quality thru the attached 1" speaker is very good, but it's just real real loud. )
What it sounds (no pun intended) like to me is the speaker is being overdriven. If it's too loud regardless of setting, try a higher impedence speaker.
Is the sound Clear? or does it crackle? If the latter then your problem is most likely a poor speaker/amp match. The amp (on the decoder) is only able to deliver so much power. If it's been overloaded with a too low impedence speaker the amp will clip. While you'll hear it more at the higher frequencies (horn, bell, etc) the whole experience will be an annoying one, including the engine rumble sounds.
If it's clear, and just too loud and you want to try a pot,
Jeff and wjstix,
What would a good starting point be? For example, 1 to 10 k ohm variable potentiometer or another value?
Would it be polarity sensitive? What about power consumption and heat load?
Thanks for all the good input from everyone.
Chris
A 1K 1 watt pot should be good. If you really want fine tune volume control you could also go with a multi turn pot. I don't have time right now to look but I think ALL ELECTRONICS has what you want.
No, they are not polarity sensitive. Simply a resistor (either carbon or wire wound) with a wiper is all they are.
davidmbedard wrote: There is one fool-proof way to quiet an MRC decoder........it involves a beer and a hammer.David B
There is one fool-proof way to quiet an MRC decoder........it involves a beer and a hammer.
David B
Rotorranch wrote: davidmbedard wrote: There is one fool-proof way to quiet an MRC decoder........it involves a beer and a hammer.David BRotor
Kinda silly to take a hammer to something because it works too well.
You want to be a little careful here since you can burn out the amplifier on some sound units by using the wrong resistance value. The following describes an "L Pad".
If you can disconnect one speaker lead, then you can measure the resistance of the speaker using an ohmmeter. This will not be exact, but close enough for our purpose. Common speaker impedances (resistance) are 4, 8, 16, 32, and 100 ohms and so forth.
Obtain a small potentiometer about 1 ½ times this value, and connect it in place of the speaker. Connect the speaker from one end of the pot to the center wiper on the pot. Set the pot to center range and fire it up. Now you can vary from full volume to zero volume.
For me the answer is simple. Don't like sound all that much anyway. I just removed the MRC decoders and replaced them with another brand. Very simple, very quiet.
Bob
I ended up moving it over to an SD unit that would only fit a 1/2" speaker and enclosure. With the volume on 1 it sounds 'just right' now. I like the Soundtraxx LC decoders for early EMD units but I don't like their single-chime airhorn, the MRC one was much better...and for early EMD units the "blat" horn really is more accurate.
O well.