PS3 sound to home stereo via fm wireless

Willy,

 

looks workable... use a small fm radio as a receiver, then....

 

Consider a powered subwoofer under the layout.  Low frequencies are not directional so it will sound like it's right there.... and you can listen to railroad tunes at the same time!

 

Ed

thanks ed...any impedence matching issues?

If you use a crossover you can just amplify the low end frequencies; if thats what you want to do. I'm guessing 200 Hz and below.

 

I'm not sure of the fidelity of the sound files when you play it louder with a decent stereo system. 

 

As eddiem said you can't tell where the sound is coming from on the low end.

 

I agree that some low thunder may be nice.

anybody know if the sound files contain the low frequencies? my loco is a gp35 -2  ps3 guilford rail system.

Some amplified subwoofers even have a low pass filter built in

 

ed

Your talking about connecting that to the PS-2/3 Engine speaker correct?  I don't know what kind of power draw that would cause.  The MTH speakers are 4ohm.  The 5V circuit that drives the audio amp also powers all the microcontrollers and feeds power to the micro processor 3.3V power supply.  So you may not want to risk it.  The audio amp is sensitive and if you blow it you will have a board repair required.  G

Did't Scrapiron try something similar (am not certain of the actual process he used) with tying his engine sounds into the stereo and a sub under the layout?

 

Perhaps he'll see this and comment..

yes..connect directly to the speaker or some sort of low signal device between the loco speaker leads and the fm wireless input. i would think the input signal at the fm wireless transmitter would be fairly minimal.

I think this is new territory, so let us know how it works out.  G

The input appears to be hi impedance, so should not load down the speaker but you will need to be careful with the audio levels so as to not over drive the transmitter.

The input of that device is surely high impedance, won't affect the load on the PS3 amp.

 As for the low frequency content it is probably better than you would think. I connected my MTH Firehouse audio to an external amp and speaker and the low frequency response is outstanding! This is a very good idea, be sure to use a high quality sub woofer.  

Over driving the transmitter is a concern.when i am running my loco[ actually a 4 engine MU/lashup, 2 powered, 2 unpowered] i often run labor rev up at nearly full volume and am quite satisfied with the sounds and volume level from 200 hz up as it rolls around the track. My question.. is there a device that would lower the input to the FM transmitter to safe levels and allow the higher volumes i normally use now?

If you give me a link to the .mth soundset file for your loco, I can extract the audio from it for you so you can see what it sounds like.  Little side project I've been working on.

went to mth page but not sure where to find the specific file. here is the link to mth for my loco.  http://www.mthtrains.com/content/20-20200-2

Looks like I jumped the gun on this.  I pulled down the soundset, but the engine sounds are encoded differently than what I've been working on.  The PS2 and older PS3 files I've been using for analysis have all had ADPCM data at various sampling rates for audio.  I'm able to pull some ambient, effects, and crew chat audio from the file for your engine (ADPCM), but the audio encoded for the engine sounds is different from what I've seen before.   I'm intrigued now so will keep cracking at it

-shelby

thanks for the research. to elaborate further on this topic it sounds like i need a cross over from the loco speaker leads to the FM transmitter which would pass low frequencies only. jeff mentioned mentioned this in a reply. are they avail? could i diy one? i have plenty of room in an unpowered unit for components.

The transmitter inputs will have high impedance so shouldn't load the speaker.  You'll probably need a pair of resistors to attenuate the signal level going into the transmitter.  I'd guess you need something like 3x to 5x attenuation.  So, for example, I'd start with a 470 ohm and a 1k ohm resistor which would be a 3x attenuator.  Even if you only use one speaker in "Mono" mode in the receiver, I'd drive both the L and R inputs together due to the way broadcast FM stereo is encoded.

willy,

 

You don't need to take up more space in the loco with filters.  Transmit full frequency audio and use a low pass filter at the subwoofer (if you use a subwoofer AND a filter is not put in)

 

Ed

ed..when i crank the volume from dcs handheld remote as i often due won't it overload the FM transmitter input?

willy,

 

As Stan said "You'll probably need a pair of resistors to attenuate the signal level going into the transmitter."  Use these to lower the signal feeding the transmitter.  The right values will keep the transmitter from distorting the transmitted signal. Then,

 

"crank it up!"

 

Ed

I did more bit pickin' and looks like its 24bit PCM @ 11025Hz sample rate.  Sounds much better than the earlier PS3 and PS2 ADPCM stuff.  I need to throw a tool together to extract everything, but do these samples sound correct pitch-wise for startup and shutdown sequences?  Should give you an idea of the quality of audio available.

http://forkineye.com/wp-conten...5-chunk1-startup.mp3

http://forkineye.com/wp-conten...-chunk2-shutdown.mp3

 

sporadic..those are correct!

Good to know, thanks!  I'll see if I can't pull the rest of the running sounds out tomorrow.

I did something similar with Bluetooth audio Tx/Rx once. I seem to recall that the Bluetooth device had a better frequency response than the FM modulator.

 

Most recordings do contain lower frequencies, but they tend to be rolled off a bit higher than would be optimal due to the small speakers we use I would imagine.

 

Lookup Braven Bluetooth speakers. battery powered and portable. Perfect for a layout. The problem becomes mixing in a multi engine environment.