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New Atlas Gp40 Sound Quality

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  • Member since
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  • From: Westford MA
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New Atlas Gp40 Sound Quality
Posted by Tophias on Thursday, January 4, 2024 9:03 AM

I recently purchased 2 of the latest released GP40's from Atlas, DCC w/sound. The decoder is a Loksound V5. To me, the overall quality of the sound is not very good. It's very high frequency focused and pretty much all I hear at all speeds is the whine of the turbos; not much of the actual prime mover. It's a completely different sound from all my Tsunami equipped locomotives. I want to get your comments regarding the sound file as well as the quality of the speaker. Can improvements be made? Thnx all!

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Posted by tstage on Thursday, January 4, 2024 10:21 AM

I can't answer your question about that particular sound file.  However, the treble and bass can be adjusted on newer/upgraded Lok5 decoders, which I did recently with a Lok5 decoder I was testing before planning to install it into a Proto 2000 E7A.

If your Atlas GP40 does not use an "OEM" sound file (made specifically by Loksound for Atlas), it should be possible to enhance the primer mover sound.  You may also be able to lower the individual turbo whine to a more tolerable level.

Lastly, if you are handy, you could swap out the manufacturer's speaker for a Scale Sound Systems (SSS) speaker.  Here's a link to one specifically for the Atlas Master GP40 speaker:

https://www.scalesoundsystems.com/product-page/atlas-master-gp38-40-2

JT is a sound engineer by trade and he tests and 3D-prints his own baffles for all his speakers.  They sound absolutely terrific.

HTH,

Tom

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

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Posted by Tophias on Thursday, January 4, 2024 10:38 AM

Thnx for the info Tom. Just wondering, his web site mentions no modification is necessary. Do you think this means he also wires a JT (or whatever the correct term is)  plug to it or is that my job?

Regards, Chris

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Posted by tstage on Thursday, January 4, 2024 11:18 AM

You're welcome, Chris.

All the speakers I've purchased from SSS don't come with any JST plug or wire - just the speaker.  If your speaker is connected via a JST connector/plug, you would only need to unsolder the old speaker and install the new one.

Tom

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

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Posted by Tophias on Thursday, January 4, 2024 1:38 PM

Yeah, I guess my mind was taking "plug & play" to the extreme. Though I would think twice about a hardwire full decoder install job, un-soldering two wires and re-soldering  to the new speaker is within my humble capabilities. 
Regards, Chris 

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Posted by tstage on Thursday, January 4, 2024 2:01 PM

Chris,

If, after adjusting individual volume and treble/bass levels, you decide to order the SSS speaker for your Atlas GP-40, let me know what you think of it.  I have yet to be disappointed with any of JT's speaker/baffle combos.

Tom

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

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Posted by jjdamnit on Thursday, January 4, 2024 2:55 PM

Hello All,

Before performing transplant surgery I would try adjusting the sound parameters; Trebble and Bass.

I have recently begun replacing my non-sound Digitrax decoders with Digitrax sound decoders with Original Equipment Manufacturers (OEM) speakers.

Apparently the first-generation of these OEM decoder/speaker combinations had fidelity issues.

The second-generation decoder/speaker combinations, in my observation, don't have fidelity problems.

That being said, I reduced the overall sound output to 75% so I don't overdrive the speaker.

I've been satisfied with the results and the volume isn't overpowering.

Hope this helps.

Post Script: If I had not been satisfied with manipulating the overall sound quality I would have upgraded to Scale Sound Systems (SSS) speakers. H.T.H. J.J.D.I.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

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Posted by OldEngineman on Thursday, January 4, 2024 9:26 PM

Tophias --

Do you have any other sound-equipped EMD engines that had turbochargers (GP40, SD40, etc.)?

If so, do those locos (with different decoders) sound different?

WHY I'm asking:

What you describe, is pretty much how the big engines sounded when you were running them. One heard "the turbo" as much as the "diesel" attached to it...just as you mentioned above.

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Posted by Tophias on Thursday, January 4, 2024 10:04 PM

Old Engine, my observations are based on my comparisons to my inventory of model locomotives with Tsunami decoders and my hearing of actual prototype gp40's and sd40's up close in yard switching. What I'm hearing from the Loksound models is way more turbo and much less diesel.

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Posted by Tophias on Friday, February 23, 2024 7:07 PM

So, I've decided to "bite the bullet" and ordered a SSS speaker. I have no doubts about  the quality of JT's quality. My reservations have to do about my abilities (hands and eyes and experience) regarding opening up a diesel locomotive. That said, I got the shell off of the Atlas GP40 so I'm off and running. I'll let you know in a couple of weeks how it goes.

Regards, Chris 

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Posted by Doughless on Saturday, February 24, 2024 6:49 PM

Tophias

I recently purchased 2 of the latest released GP40's from Atlas, DCC w/sound. The decoder is a Loksound V5. To me, the overall quality of the sound is not very good. It's very high frequency focused and pretty much all I hear at all speeds is the whine of the turbos; not much of the actual prime mover. It's a completely different sound from all my Tsunami equipped locomotives. I want to get your comments regarding the sound file as well as the quality of the speaker. Can improvements be made? Thnx all!

 

The sound quality of newer Atlas locos seem to be all over the place.  I just purchased 2 new Gold GP38s and the sound is very low. From the factory. 

I set the sound higher.  I made sure to set CV 63 to its highest level.  Then had to set CV 31 to 16 then 32 to 1 to then raise CV 259 (prime mover) to its highest level.  It helped quite a bit.

The new PM setting tends to drown out the horn...as is typical with LokSound.  Loksound has always been pretty poor when it comes to being able to set the horn significantly louder than the prime mover, just never enough difference in the volume, IMO.   So I set the PM CV back down to about 90 to be able to have the difference between horn and PM seem more prototypical.

But yes, the turbo sound is awful, IMO.  Both Lok and Soundtraxx say that the sound file is a straight recording, can't be changed, but the absence of real-loco bass sounds that our little speakers can't produce to offset the turbo is noticeable...so all I hear is the turbo.  Which is why my entire fleet has been converted to locos with nonturbo PMs.  I freelance, so that gives me the liberty I guess.

Please let us know if the SSS speaker made a difference.

- Douglas

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Posted by Tophias on Sunday, February 25, 2024 5:28 AM

One important comment I failed to make since I started this discussion is a few weeks ago is I discovered I could replace the LokSound decoder easily (even for me) just by removing the dynamic brake fan cover and pulling out the decoder. I purchased a 21 pin ST Economi and put it in. Easy peasy. The sound file is quite different (again my opinion) from the LokSound with more PM sound. Yes, it also exhibits turbo sound but both the PM and turbo seem more in balance with what I am used to hearing in both the model and prototype worlds.  Overall, the more I listen to the ST decoder in this Atlas the more I believe my issue isn't with the Lok decoder but with the Atlas cheap speaker.  And yes, I will keep the Lok decoder safe and use it along with a decoder buddy when I get the nerve up to convert and old DC locomotive to DCC.

Regards, Chris

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Posted by Tophias on Wednesday, March 6, 2024 10:07 PM

tstage

Chris,

If, after adjusting individual volume and treble/bass levels, you decide to order the SSS speaker for your Atlas GP-40, let me know what you think of it.  I have yet to be disappointed with any of JT's speaker/baffle combos.

Tom

 

So Tom (and all), sorry it's taken me a bit longer to get back to you with my results. Just been busy with life. Anyway, I've installed two of SSS direct replacement Rectify Series speakers into two of the three GP40's I purchased.  The improvement is remarkable. They exceed my expectations.  Really easy to do even for a clutz like me.  I couldn't be more pleased. The bass response is remarkable. The third loco I'm having a problem getting the shell off. The other two weren't too bad but for some reason this one is being stubborn.  I'm bringing to "my guy" Friday to ask for him to get it off. I'll just break handrails or something if I keep at it.

Regards, Chris 

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