Moosh Bronsun Posted June 16, 2020 Share Posted June 16, 2020 So my Heresys are sounding really good and I decided to add my cheap HT sub as I had before. Whats weird is that with the sub plugged in all my preamp outputs are send a summed signal. When I play a test track with panning, both channels are summed and sent to both speakers. Weird. So after unhooking everything And reconnecting I have discovered that the Y adaptor summing the left and right signal to mono which then plugs into the sub is the cause. I have no idea how it’s sending back a summer signal to both sets of outputs. Bizarre! So my question is: how is this possible and could it be a faulty adaptor? If I run one of the channels into the sub (no Y adaptor in the chain) it’s fine. If the Y is in the chain but the sub is off then it’s fine. Thoughts?? Quote Link to comment Share on other sites More sharing options...
baron167 Posted June 17, 2020 Share Posted June 17, 2020 What's your sub Y adapter being plugged into exactly? What inputs does your sub have?Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Moosh Bronsun Posted June 17, 2020 Author Share Posted June 17, 2020 (edited) 19 minutes ago, baron167 said: What's your sub Y adapter being plugged into exactly? What inputs does your sub have? Sent from my iPhone using Tapatalk The Y sums the stereo RCA and is plugged directly in to the sub. The sub is a basic home theater sub that has just a LFE in. Edited June 17, 2020 by Moosh Bronsun Quote Link to comment Share on other sites More sharing options...
baron167 Posted June 17, 2020 Share Posted June 17, 2020 The Y sums the stereo RCA and is plugged directly in to the sub. The sub is a basic home theater sub that has just a LFE in.Yes, but what stereo RCA out of what? Your stereo amp preamp out? And that's not what the LFE input is for on the sub. Probably should stop and disconnect before it causes permanent damage.Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Islander Posted June 17, 2020 Share Posted June 17, 2020 LFE In on the sub is just fine. Are you using a receiver and does it have a Sub Out or LFE Out socket? Y adapters are rarely needed, except in an unusual configuration. The Sub channel is often summed L+R already, but if you take it from either the Main Left or Main Right pre-amp outputs, you can’t also use the Speaker Out for that channel. Also, a sub is a sub, cheap or not. Even the very expensive subs are often marked Home Theatre Subwoofer on the box. It should have either a Sub In or an LFE In. Either one should work fine. 1 Quote Link to comment Share on other sites More sharing options...
Moosh Bronsun Posted June 17, 2020 Author Share Posted June 17, 2020 @baron167 @Islander Sorry, I didn’t mention. I’m sending to the sub from stereo outs on my line stage. Then I was using a Y adapter into the sub. Quote Link to comment Share on other sites More sharing options...
Edgar Posted June 17, 2020 Share Posted June 17, 2020 The various outputs are probably connected in parallel, so when you short one pair together, you short all pairs together. http://silentsky.net/wordpress/archives/624 Quote Link to comment Share on other sites More sharing options...
Moosh Bronsun Posted June 17, 2020 Author Share Posted June 17, 2020 42 minutes ago, Edgar said: The various outputs are probably connected in parallel, so when you short one pair together, you short all pairs together. http://silentsky.net/wordpress/archives/624 Ahhhhh, so that sounds like what I had happening. So is there a cable to do what the linked article specifies? Quote Link to comment Share on other sites More sharing options...
Moosh Bronsun Posted June 17, 2020 Author Share Posted June 17, 2020 Seems like a D.I. Box would work Quote Link to comment Share on other sites More sharing options...
Edgar Posted June 17, 2020 Share Posted June 17, 2020 9 hours ago, Moosh Bronsun said: Ahhhhh, so that sounds like what I had happening. So is there a cable to do what the linked article specifies? Search for "stereo to mono adapter with resistors". There are some, but they're not cheap. 1 Quote Link to comment Share on other sites More sharing options...
Marvel Posted June 17, 2020 Share Posted June 17, 2020 If you are up to it you could make one very inexpensively. Quote Link to comment Share on other sites More sharing options...
babadono Posted June 17, 2020 Share Posted June 17, 2020 Not to be a d*%k but of course a Y adapter shorts TWO OUTPUTS together. That is not what Y adapters are for. They are to feed TWO INPUTS with one output. I use them on the inputs of my RSW-15 subs. This helps insure the auto on feature works even at relatively low input levels. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted June 17, 2020 Share Posted June 17, 2020 13 minutes ago, babadono said: Not to be a d*%k but of course a Y adapter shorts TWO OUTPUTS together. The word BUT negates or cancels everything that goes before it. LOL 1 Quote Link to comment Share on other sites More sharing options...
Marvel Posted June 17, 2020 Share Posted June 17, 2020 You can put a 10k resistor on the hot side of each channel, tied onto another 10K and send to the sub. The 20 k across the two legs will maintain your stereo signal. Quote Link to comment Share on other sites More sharing options...
Moosh Bronsun Posted June 17, 2020 Author Share Posted June 17, 2020 16 minutes ago, babadono said: Not to be a d*%k but of course a Y adapter shorts TWO OUTPUTS together. That is not what Y adapters are for. They are to feed TWO INPUTS with one output. I use them on the inputs of my RSW-15 subs. This helps insure the auto on feature works even at relatively low input levels. Well not to be a d*ck but the cable I purchased does not specifically state whether it splits or sums a signal. Either is what a Y cable can do. The can feed TWO INPUTS or feed TWO OUTPUTS. Quote Link to comment Share on other sites More sharing options...
babadono Posted June 17, 2020 Share Posted June 17, 2020 If you wish to sum two outputs without one interfering with the other you need a mixer. This can be as simple as an adapter with resistors as Edgar suggested all the way up to the most elaborate mixing console in the world. The modified cable (cheapest) route introduces a small error into the summed signal because the input it is feeding is not a summing junction. Whether you can hear the error is debatable. Quote Link to comment Share on other sites More sharing options...
Marvel Posted June 17, 2020 Share Posted June 17, 2020 See above ^^^ 🙄 Quote Link to comment Share on other sites More sharing options...
Moosh Bronsun Posted June 17, 2020 Author Share Posted June 17, 2020 45 minutes ago, Marvel said: If you are up to it you could make one very inexpensively. Looking into this now. Seems straight forward but I haven't soldered in 10,000 years. In fact I just dug out my pen and I think I am out of solder. DRATS It will cost more to DIY but I may go that route anyway because I am not all that smart but like to learn. Quote Link to comment Share on other sites More sharing options...
babadono Posted June 17, 2020 Share Posted June 17, 2020 4 minutes ago, Moosh Bronsun said: Well not to be a d*ck but the cable I purchased does not specifically state whether it splits or sums a signal. Either is what a Y cable can do. The can feed TWO INPUTS or feed TWO OUTPUTS. Nope. It can feed TWO INPUTS or SHORT TWO OUTPUTS TOGETHER as you have found out. Quote Link to comment Share on other sites More sharing options...
Marvel Posted June 17, 2020 Share Posted June 17, 2020 Just now, Moosh Bronsun said: It will cost more to DIY but I may go that route anyway because I am not all that smart but like to learn. 1/4 watt resistors would be more than adequate. I would be so crude as to rip apart a couple cheap cables, solder everything together and wrap with tape. If it does what you want you could tidy it up, but that's just me. Quote Link to comment Share on other sites More sharing options...
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