Challenge: Automate turning woofers on/off via theater receiver.

[Knightrider]

Miller:

I have the parts to mirror your project here.  Can you give details on the amplifier and other gear?

[kamiller42]

This forum is gold. I think I have solved my problem after doing a little searching. I setup the TM751 as a relay by having CM15A send RF command. Very good article... http://kbase.x10.com/wiki/Setting_The_CM15A_to_send_RF_Commands

Back to the receiver situation...

I am going to buy the following:
2 SR227 Outlets
1 PF284

My receiver is an Onkyo TX-SR875. Here's the manual with all its connections laid out...
http://63.148.251.135/redirect_service.cfm?type=own_manuals&file=TX-SR805_875_B_En.pdf

One sub will be attached to each SR227. I have 2 Rocket UFW-12 subs.

Is there anything else I should be purchasing?

[Knightrider]

Let's keep our fingers crossed that the X10 PLC will be reliable in reaching the 227's.  Other than that, I see no issues.

[JeffVolp]

Gee, I'm addressing almost the same issue here (a different Onkyo model).  Right now I'm just using a little 2-button keychain remote and a TW751, but I plan to replace the room dimmer switch with a Leviton 2-way model that transmits when it is turned on or off locally.  So, when I turn on the lights, the Onkyo equipment will be powered up too.  And vice versa.

Jeff

[HA Dave]

I discovered X10 when I build my Home Theater. I wanted a little wow factor... and I thought dimming the lights might do it.

I used a Harmony-Logtech remote and an X10 Infrared Mini Controller (IR543). But there are a bunch of ways to set this stuff up... its more just choice than anything else.

[dave w]

Dave,

It would depend on how clean the audio is, what levels were driving it, and which output you used.  I was thinking about driving it with the high end output.  Unless it's very clean, there should be some constant output regardless if it's audible.

Yeah, it might work then. I have never tried to trigger a PF with audio, but just thought any quiet period might make the PF send an OFF.

"kamiller" if you experiment with audio triggering a PF tell us of your findings and outcome.

[kamiller42]

Well, the parts are on order. I won't be able to start this weekend, but probably the weekend after.

KnightRider, I don't think there should be a problem with the 227's receiving signal. They are all on the same electrical circuit. I can check using a TM751 in the receive AC socket and a LM465 in the sub socket. The LM465 should respond.

Which audio signal were you thinking we could monitor?

Dave, I am also curious to see how the PF responds to different audio levels. Turns off when silent, fries when too high?

[dave w]

Dave, I am also curious to see how the PF responds to different audio levels. Turns off when silent, fries when too high?

I think it WILL turn off when silent, as in between songs. Knight thinks it might stay ON depending on the signal input. I doubt "pre-amp" or "Line Out" level will be high enough to get the PF to send an ON. Only testing will tell. I think max input to PF is 18V AC (or DC) for a steady voltage. Audio, as in speaker output direct from amp, might be higher since it is not steady state. But I wouldn't push it too much. You will probably have to "WAG" the voltage the PF might see if you drive it with speaker output. For example 100 watts into an 8 ohm speaker will be nearly 30V of drive to the speaker but that would not be continous.

[JeffVolp]

Having spent a fair amount of time designing audio equipment years ago (1/2KW RMS back in the 70's), I found that speaker voltages are usually quite low.  The only time it gets up into the 10Vpp+ range is when you start pumping out some real power, such as music with heavy bass.  It may be difficult to trigger anything automatically from just the speaker output.

The Onkyo subwoofer is supposed to power down when it is not receiving a signal from the receiver.  However, in the power-down mode, it still seems to consume almost 10W.

Jeff

[kamiller42]

Having spent a fair amount of time designing audio equipment years ago (1/2KW RMS back in the 70's), I found that speaker voltages are usually quite low.  The only time it gets up into the 10Vpp+ range is when you start pumping out some real power, such as music with heavy bass.  It may be difficult to trigger anything automatically from just the speaker output.

The Onkyo subwoofer is supposed to power down when it is not receiving a signal from the receiver.  However, in the power-down mode, it still seems to consume almost 10W.

Interesting. I never measured the volts and amps on a speaker wire or a sub pre-out. So I guess when it comes to high power speakers, it mostly about pushing amps.

My Rocket subs when sleeping are the same when it comes to power consumption. It's between 10 and 15 watts, and I have 2.

[JeffVolp]

One sub will be attached to each SR227. I have 2 Rocket UFW-12 subs.

Wow, those are REALLY nice subwoofers, but they cost almost 10X what the Onkyo cost.

The Onkyo does a pretty good job.  At least it doesn't make the obnoxious sounds the Panasonic did when pushed a little too hard.  I'd like to add a second - maybe that will be my payback after I assemble another hundred XTB-IIRs...

Jeff

[kamiller42]

Yes, they are pretty nice. Too nice for what the owner charged for them. He charged too little and that left him cash strapped, so he made a couple of bad moves which caused the company to close the doors and him in jail. Oops. Shame because the company was able to hire some really good speaker designers. Sadly, some were never fully compensated.

Was my understanding of speaker signals on the wire correct on voltage and amps?

[JeffVolp]

Was my understanding of speaker signals on the wire correct on voltage and amps?

It is all about decibels.  It takes relatively little power for normal listening levels.  But it takes a lot of power (voltage and current) to move the volume of air necessary for thunderous bass.

Voltage and current are relative to the impedance of the speakers.  My quad amplfier (from the 70's) does 10A peak into 4 ohms, or 40V peak, 80Vpp.  But, that is at max volume level just before clipping.  In a home theater, that would be the loudest explosions or low-frequency special effects on a DVD.

Jeff

[kamiller42]

I think we're over thinking on this problem. A friend of mine said something that made say "Duh!" He suggested using an old low power power supply on the outlet at the back of the receiver. Cut the head off and attach to PSC01. Power goes on, power supply goes on, PSC01 sends its command, and all done.

I have an old 6V, 300ma supply I think I will try using with the PSC01.

[JeffVolp]

Sure, if you have a switched outlet, that is an easy way to go.  My Onkyo RC160 doesn't, so that's why I plan to use the room light dimmer to send a command to turn the equipment on.

Jeff