Speaker Splitter - Need Advice please! (1 Viewer)

[Petetheman]

Hi, I'm looking for some advice on using a (passive?) speaker splitter.


Instead of sending an amplified signal to the splitter and then off to the speakers, my intention is to send the signal straight from the desktop PC's soundcard, straight to the splitter. I'm assuming that the signal coming from the sound card is either unamplifed or very weakly amplifed as you would see in a pre-amp sort of signal. Once going through splitter, it routs as follows:

1) PC front speakers by way of subwoofer which must be where it gets amp
2) Home Receiver/Amp (for watching movies via the TV)
3) Remote transmitter which then sends signal to powered speakers
4) travels 40 feet to upstairs Amp (15x2rms)

This is the unit I'm installing:

Amazon.com: Monster Cable SS4 Multi-Speaker Selector: Electronics

My main concern is that I'm not damaging my amps or speakers by underpowering them or by splitting the signal the way I am doing. My "splittler" (linked above) is supposed to be used with the amplifer in line BEFORE the splitter. I plan to use it in the opposite manner. Does this propose a problem to signal strength?

Also, this particular splitter has "amplifer protection" which is supposed to be turned on whenever multiple speaker outputs are being used. This "protection" can be turned on or off. Can someone explain to me what such protection is needed and what the dangers are. I'm confused. Should I even need to use it considering how I plan to install? I really need some basic information on how speakers and amps are damages by low volume or weak signals. I'm confused on why this occurs and how to prevent it.

Any comments appreciated!

 

[Wayne A. Pflughaupt]

Hi Pete,

That switcher is supposed to go between an amplifier and speakers. The signal from your computer sound card is line level, not speaker level. After all...
...you don't send speaker cables to the input of another amplifier.

What you need is a line level distribution amplifier like this.

Regards,
Wayne A. Pflughaupt

 

[Petetheman]

Thanks for reply.

Line level or speaker level, I'm not sure what the difference is.

Leaving the PC Sound card, the front speakers exit via a 3.5mm stereo cable and then go to the subwoofer which (I assume) provides amplification before the signal carries on to the front speakers. (The rear speakers and the sub woofer speaker come off the sound card also and then go to subwoofer, but they do so with different 3.5mm cables.

What I've been doing is unplugging the front speaker 3.5mm stereo cable whenever I want to send the signal elsewhere. For example, I have some active (powered) speakers that run off a wireless signal. The wireless transmitter also has a 3.5mm jack so when I want to run these speakers off the sound card, I just plug them in INSTEAD OF the front speakers.

Sometimes I like to watch Internet streamed video on my TV, so for audio I unplug the PC front speakers (coming from sound card) and I send them to my home receiver/amplifier. (I have make a transition from 3.5mm to rca, but it's easily done). Then whatever signal is coming off the sound card gets amplified by the home receiver and I listen though speakers that are hooked up to said receiver.

So what's the big deal? I'm just trying to take away the need to physically unplug and replug different cables in and out. With the splitter I already have, why can't I do that? My intention would be to send that PC sound card signal anywhere I want including the PC speakers, the remote speakers, or the home stereo receiver/amplifier. OR, I might like to send it to all those speakers at the same time.

The splitter I'm using has no amplifer. No power. It relies on mechanical switches to make or break the connections to the speakers.

Please tell me what's wrong with using this splitter in this manner and explain why I need something else instead?

Thanks. I admit to being ignorant on this matter, but I'd really like to understand the reasoning behind your suggestion.

Pete

 

[Wayne A. Pflughaupt]

Another issue, line level signals require shielded cable, while speaker level signals do not. Thus the wiring inside the speaker switch will not be shielded. Running line-level signals through it may well result in unwanted noise. (See the article in my signature on DIY cable making for details on what shielded cable is and why it’s important.)

Bottom line, for what you’re wanting to do, you need an active distribution amp like the one I linked above, that’s designed specifically for line-level signals. It won’t add any noise to your systems and there won’t be any signal loss from splitting out the signal. All you have to worry about is transitioning from 3.5 to RCA, but as you noted, that’s no big deal.

Wayne A. Pflughaupt

 

[Petetheman]

Wayne,

First of all, thanks for your time and feedback and thanks for explaining what might be obvious to most.

Ok, I understand what you mean by line level. I actually made this assumption in my OP saying the signal was unamplified or low amplified, sort of like you'd see in a pre-amp signal. Now I understand the correct term is line level.

Everything you describe about my PC card and the way the speakers are amplified sounds totally correct.

Your words in BOLD.

It’s designed to go between an amplifier (like your home theater receiver) and multiple speakers, to enable the use of more speakers than you would normally use. As you may know, connecting too many speakers to an amplifier can blow it. A speaker switch like this one will have all kinds of high-powered resistors wired into it to maintain an 8-ohm load (i.e., make the amplifier “think” it only has one set of speakers connected instead of four). Do you really want all that extraneous crap in your signal chain?


Good question. First a little update. Since my last post I've actually soldered my own "adapter" cables so that I can connect everything to match the speaker wire inputs of the splitter I'm using. No banna clips. I just put the bare wire into the output speaker terminal on the back of the unit and did the same with the input.

INPUT: Front speaker 3.5mm stereo output of PC going to splitter
OUT1: Adapted 3.5mm going to PC speakers
OUT2: Adapted RCA cable set going to home receiver
OUT3: Adapted 3.5mm going to remote unit which, in turn, sends wirelessly to active speakers.

As I said, I used all these configurations before but I was manually unplugging and replugging each output each time I wanted to redirect the signal. The point is, now that I'm using the splitter the sound quality of the signal is the still good and unchanged. It's at least as good as a nice clear FM radio station. Now the real test I guess will be the long wire that goes upstairs and then meets up with it's own amp. I don't have the amp so I can't test that yet, but maybe I'll have some signal noise.

So if you are concerned about signal quality, it's not an issue. However, if using this kind of splitter will some how damage my speakers or the seperate amps that they are using then I am concerned. However, if the signal quality sounds fine, then what are the technical reasons for why I should be concerned?

I openly admit to not understanding what resistors are used by the splitter I'm using (linked in my OP). It does have an "amplifier protection" button you are supposed to leave engaged when multiple speakers are being used and when the input is amplified. There's no technical explanation in the manual as to what it does. I can discern no difference in signal strength or quality when I push it in or out, but I'm not sure if it matters given that no amplification is going INTO the splitter. Please share if you have knowledge on what this button does.

So to answer your question about "all that extraneous crap", I guess it doesn't matter to me so long as the signal quality is good (which it is) and so long as my amps and speakers aren't being damaged.

But putting that aside - for merely practical considerations, take a look at the back of this unit and note that it has spring-loaded terminals, like you see on the back of many home theater receivers for speaker wire connections. You might want to think about how you’re going to connect your 3.5mm cables to that...

Excellent point. In my case I had some old adapters laying around and I do know how to solder, so I took care of it watching TV last night.

Another issue, line level signals require shielded cable, while speaker level signals do not. (See the article in my signature on DIY cable making for details on what shielded cable is and why it’s important.) Thus the wiring inside the speaker switch will not be shielded. Running line-level signals through it may well result in unwanted noise.

Bottom line, for what you’re wanting to do, you need an active distribution amp like the one I linked above, that’s designed specifically for line-level signals. It won’t add any noise to your systems and there won’t be any signal loss from splitting out the signal. All you have to worry about is transitioning from 3.5 to RCA, but as you noted, that’s no big deal.


Wow, very nice article on soldering. I picked up a few tips and ideas for sure. I didn't read a lot on why it was important so shield cables, but as you say above, it must be your concern for unwanted noise which brings me back to my previous point. If I'm not getting any noise.. if the signal quality is the same as it was when not using the splitter.. then why the need for more heavier shielding and why the need for a splitter that's different from the one I'm using? How can a signal with good sound quality do damage to speakers and amps? Even if I can't hear the difference, is there something a "speaker level" splitter can do to a line level signal that would damage amps or speakers further down stream? If you have a link or an technical explanation for this I'd like to learn.

Sorry for the long post. I'm trying to be clear and I'm obviously not well versed on the fundamentals. I really do appreciate your advice and I'm doing my best to understand.

Pete.

 

[Wayne A. Pflughaupt]

I’ve never seen one of these things with a switch like that. My best guess is that it kicks in all those resistors to maintain an 8-ohm load to the amp when multiple speakers are being used. If that’s true, then bypassing it would give a straight-through connection when using only two speakers, bypassing all that stuff for a more pure signal path.

That actually might work out well for you, since you don't need to maintain an 8-ohm load in this situation. If you can get what you need with the switch bypassed, then do it that way.

Regards,
Wayne A. Pflughaupt

 

[Petetheman]

Wayne,

I feel guilty I've dragged this out so long. Thanks for your patience.

Sorry – I know there’s a lot there - I should have directed you to the bottom of the first post:

No problem. Your article is a good resource I'll explore further, but so far I've been guilty of only skimming through parts of it.


This particular cable is a balanced mic cable. You can probably get away with a marginal shield with balanced audio signals because it’s a protocol with outstanding noise rejection properties. Not so with the unbalanced signals we typically use for home audio. or us, the shield is what makes or breaks noise rejection properties, so it must be substantial and robust.

Ok, I think it's finally sinking in. So the symptom for not-enough-shielding is noise? As long as I don't hear distortion noise I guess I can assume it's okay. I'll use the same test criteria when I get the long run output installed.

(responding to long upstairs wire...)
Just make sure you use shielded cable, not speaker cable, and you should be fine.

Okay, I was gonna just use 14 gauge speaker wire (which is already in place) but I'll do as you advise and fish through something shielded. Is plain old typical RCA cable good enough or should I look for something with heavier shielding?

Damage is not an issue (notice I haven’t mentioned it in my previous posts). I would think the resistors would drag down (reduce) the output signal level, but if it’s working for you, and you’re not getting any extraneous noise, and you don’t mind dealing with the unusual connections, then you’re fine.

Sorry. I didn't mean to suggest you said damage would occur. That was just my own ignorance trying to understand your reasoning. I'm glad to hear I might be able to use the splitter after all. I was hoping I wouldn't have to buy something new and I really wanted to have switches (buttons) so I could turn the outputs on or off. I guess the real test will be the signal quality of the yet-to-be-installed output with the long run of cable.


I’ve never seen one of these things with a switch like that. My best guess is that it kicks in all those resistors to maintain an 8-ohm load to the amp when multiple speakers are being used. If that’s true, then bypassing it would give a straight-through connection when using only two speakers, bypassing all that stuff for a more pure signal path.

That actually might work out well for you, since you don't need to maintain an 8-ohm load in this situation. If you can get what you need with the switch bypassed, then do it that way.

Ok thanks for the explanation about the button. Doesn't seem to effect anything, but a straight-through connection seems to be the logical choice, so I'll just leave the button un-activated.

Let me push my luck and touch on two other issues...

For my adapters, I used a "Y" cable (3.5mm x 2 RCA) and discarded the RCA ends. Obviously there were two separately shielded leads coming off. After stripping one of the leads, I could see a bare wire conductor running along (much like in romex). Being bare, I assumed it was negative. Then, there was another inner shielded conductor which actually appeared to be a smaller gauge. The casing of this shield was red. I stripped that too and assumed it was the positive conductor. Do I have the polarity right?

Ok, regarding the line level signal I send to the home stereo receiver from the PC sound card... My wife and kids sometimes leave the amp on but with little or no volume. I've heard that this can damage the speakers or amp. Is this so? Is there some kind of passive cross over I can put inline to block very low volumes from coming through and hurting the speakers? Or, am I once again being paranoid about potential damage?

Wow, thanks again Wayne. I think I'm good to go now thanks to you. I can't explain how much I appreciate people like you who offer their time and patience to help total strangers like me.

Pete

 

[Wayne A. Pflughaupt]

Happy to help, Pete.

By the way, if you can bold text, you can just as easily put it in a quote box: quote /quote (just add brackets). Even better, there’s a handy icon above the text box field (between the envelope and the smiley face) that will do it for you.



You can get these jacks in 1/4”, 3.5 mm, or RCA versions; you could use the 3.5 mm at the computer end (these 3.5’s aren’t hard to solder), and then use a single stereo cable between the wall and splitter box – cool, huh? At the other end, you could use a couple of RCA jacks mounted to the wall plate (or buy a wall plate with RCAs already installed). That would let you use a typical pair of stereo RCA cables between the wall and component. IOW, this option would let you dispense with the various adapters, splitters, etc. altogether.

Regards,
Wayne A. Pflughaupt

 

[Petetheman]

Wayne,


Okay, assume I use the 3-conductor cable you linked to (instead of 4 wire cable). Because it only has one shield/bare/negative wire, my first thought would have been to splice that shield wire (via solder or some kind of wire nut) in order to make speaker leads Right (+/-) and Left (+/-). The reason you are suggesting soldering the 1/4" jack and then using the RCA adapter is to avoid the hassle of splicing that shield wire myself. That's a good idea, but I'll check the costs of the jacks and make a decision.

Remember that on the speaker-level-splitter than I'm inappropriately using, the inputs and the outputs accept only bare wire or those banana style clips. If I do the 1/4 to RCA cable method I may have to take it a step further and solder on banana clips in which case, so it might be more work than just splicing and soldering from the start. I'll think about it.

To be clear, for my half-ass soldering project I wasn't using solder made jacks. I was cutting up older Y adapters I had on hand, with the RCA side being the scrap side:

Newegg.com - Computer Parts, PC Components, Laptop Computers, Digital Cameras and more!

If I decide to cheap out and use this method along with the good cable you linked to, do you think I'm in danger of a lot of bad shielding problems? (I've got more time than money, or maybe just it's just a stubbornness to make use of what I've got on hand.)

For my purposes, I'll pass on the clean look with the quick change switch plates. I actually did solder on a made-for-soldering female 3.5mm stereo jack. You are sure right about them not being worth the trouble. At least when I chop an old "Y" adapter I can cut off the RCA ends and work with 2 sets of 2-wire cables. However, your 1/4" method might end up being the way to go. Like I said, I'll think on it.

Thanks again Wayne.

Pete

 

[Wayne A. Pflughaupt]

The wall plate method was assuming you were making the 40 ft. run in-wall, but that was presumptuous on my part. If you’re not running the wiring in-wall, then in-line jacks and plugs with the splitters/adapters would certainly be the way to fly. But if you are running in-wall, and don’t already have all the splitters and adapters, the wall plate method may be cheaper than buying them. You can get the panel-mount 3.5 mm and RCA jacks at Radio Shack, if you can’t find them at Parts Express.

Regards,
Wayne A. Pflughaupt

 

[Petetheman]

Wayne,



Ah, ok. Maybe I will go that way.

I just recently got the amp (for long run). I used the speaker wire already in the wall to connect the amp (with a soldered RCA jack) to the splitter downstairs. You were absolutely right. LINE NOISE. Buzz/hum. I'll place my order for the cable today.

Wow, what can I say? You've been a tremendous help. Thank you for ALL your patience and solid advice. Thanks to you I've not only found a good solution for this project, but I've gained some good fundamental audio knowledge along the way. I'll spend some more time with your articles while I wait for the cable to arrive.

Sincerely,

Pete

 

[Wayne A. Pflughaupt]

Good thing you have some time to burn, you’ll need it wading through all that! As you can imagine Reader’s Digest wouldn’t hire me...

Good luck with the project!

Regards,
Wayne A. Pflughaupt

 

[Petetheman]

Wayne,

Hey, I don't know if you're checking this thread, but I ran into a bit of a snag. I got the cable you suggested from partsexpress. It's gonna be much longer than 40'. Considering my project, how long can I run this type of cable and still maintain a decent audio signal? Is 100' too long?

http://www.parts-express.com/pe/psho...number=100-246

Thanks,

Pete

 

[Wayne A. Pflughaupt]

The only significant issue with a long cable run is that there may be a slight drop in signal strength. IOW, the signal level might be a bit lower compared to if the component was local and connected with 6-ft. cables. That's nothing that the volume control can't take care of, just like when you have a CD that's not recorded as "hot" as another.

Regards,
Wayne A. Pflughaupt

 

[Petetheman]

Wayne,

That's it. All done. All good. The 40' run turned out to be about 85' instead, but once installed all line noise is gone. Great suggestion on the cable.

I noticed a little line noise on run going to the home stereo receiver so I went ahead and rewired that too. I know you said it shouldn't matter and you were right. AFTER installing the new shielded cable I still have noise which means it's coming from elsewhere. I'll go back and check all the connections this weekend.

The other suggestions you made were also valuable. For example, I used the wall plate version of the RCA jacks to bring the cable in. Soldering was easy.

Long story short, your advice was excellent and time saving. You not only helped me to the right thing, you helped me to use the hardware I had rather than insisting I go buy something else you were more familiar with. That shows a higher level of skill on your part. Much appreciated!



Have a good one!

Pete