G Scale Model Train Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
67 Posts
Discussion Starter #1
Hi guys,

I just wondering if you could help me out? Last week I installed a new P5 unit into one of my USAT NW2s using two speakers. I wired them out of phase using the standard Phoenix SP-2.5SQ in the fuel tank, and a smaller SP2.0 under the top radiator grill facing upwards. After testing the loco it sounds fantastic with a really deep body to the sound. The only problem is I'm getting a sort of speaker pop occurring regularly when the revs start to increase. Its like an electrical spike or something but I'm just not really sure. Does anyone know what could cause this? I've tried experimenting with some of the different settings using the computer interface like turning up the track voltage filter but I have had no sucess.

I was just wondering if anyone has had a similar problem? What do you guys suggest?

Thanks for your help,
Gavin
 

·
Premium Member
Joined
·
369 Posts
That is likely the Air pop background sound effect. It is supposed to represent the compressor pop off that would occur when the diesel is idling. You can control this in the software. If you do not like it turn it off or turn the volume for this effect down. You can also adjust the interval.

Jonathan/EMw
 

·
Premium Member
Joined
·
369 Posts
By the way, if you wire the 2 speakers IN PHASE you will get even more bottom end bass to the sound, but will sacrifice a bit of spatial quality. For a sound source like this , in phase is generally better.
Jonathan/EMW
 

·
Registered
Joined
·
67 Posts
Discussion Starter #4
Hi guys,

Thanks for the reply. It's not the the air pop effect as that only comes on when the loco is idling. I also switched this effect off just to make sure and still no difference. It is a definate speaker pop as if the speakers are somehow being overloaded with a smal voltage spike as the revs increase, but I just can't understand what I did differently to my other locos. Any help you can give me would be grea1t

Thanks again,
Gavin
 

·
Super Modulator
Joined
·
20,522 Posts
I'm assuming you are running DC and not DCC.

Does it do this when on rollers?

If so, disconnect the motor leads (assuming you are connected to the rails) and see if it still does it.

Regards, Greg
 

·
Registered
Joined
·
67 Posts
Discussion Starter #8
Greg: I'm running DCC. It does make the noise when on the rollers, but I'll try disconnecting the motor leads to see if that makes a difference.

Thanks again,
Gavin
 

·
Premium Member
Joined
·
5,620 Posts
I'm hoping you have the right power leads hooked to the Board. Track and not motor. later RJD
 

·
Registered
Joined
·
67 Posts
Discussion Starter #12
Thanks Greg, I'll do it this evening and let you guys know.

Thanks,
Gavin
 

·
Registered
Joined
·
67 Posts
Discussion Starter #14
Hi,

Sorry I've been a bit late with a reply but I'm still away on holiday abroad and won't be home till the 24th. My Dad and I are actually on a railfanning trip to California and Nevada, taking in Winterail and some other stops along the way!

I'll let you know how I get on with the P5 when I get back home. Thanks again for your help.

All the best,
Gavin
 

·
Registered
Joined
·
67 Posts
Discussion Starter #15
Hi guys,

I finally got round to looking at the NW2 again.

I tried a few other tests, disconnecting the motor leads from the decoder (thanks Greg!), etc but the noise was stil there, although it really isn't too bad. I tried loading some different sound sets into the P5 just to compare, and it was gone! I guess it must be a feature in the original recording of the ROM file. I was running it outside today and it was almost barely noticeable so I think I'll soon forget about it. It's just quite strange thats all as the quality of the NW2 sounds are amazing!

It was a newer version of the NW2 ROM file that I'm using, has anyone else noticed it?

Anyway, thanks again for all your help guys, much appreciated!

All the best,
Gavin
 
1 - 15 of 15 Posts
Top