speakers and cables


this is about me being a loser and problem creator.

I finally got a 2nd subwoofer and I was excited to hook it up. Well, not too excited. I knew it would be a pain to hook it up. I was excited to hear it. I spent over 90 minutes connecting the speaker wires to my power amp. When I turned it on, the left channel was gone. It blew the fuse. I disconnected everything, replaced the fuse, hooked it up again. It worked for 10 seconds, blew the fuse again.

The way I hooked them up was I went from the sub speaker out from both subwoofers, rolled the left and right side wires together so I had 4 wires that I connected to the left and right plus and minus channels - speaker binders on the power amp. What are my options? My preamp has no sub out. Nor my amp.

Stupid question: should I just go from left to left on one sub and right to right on the other sub?

grislybutter

The way I hooked them up was I went from the sub speaker out from both subwoofers, rolled the left and right side wires together so I had 4 wires that I connected to the left and right plus and minus channels - speaker binders on the power amp. 

Uh, what?  I’m blowing a fuse just trying to figure out what you were trying to do and why it took 90 minutes.

I believe it's irrelevant to the question why it took me 90 minutes.

But if wondering about it is amusing to you, wonder away.

Yes, I think that “ left to left on one sub and right to right on the other sub?” will work better. I’m doing that with an extra pair of RCA outputs on my preamp to my left and right sub.

https://audiocurious.com/high-level-input-vs-low-level-input/
https://theaterdiy.com/subwoofer-high-level-inputs-vs-rca/P

 

Have you considered using the hi level inputs in the subwoofer? Read the links. .

 

Use the speakon cable to connect the amplifier to the high level inputs on subs.

Wire the red and yellow wires to the positive speaker post and the black wire to the negative post. Repeat for the other channel. 

An external high pass filter maybe?  I bought a M&K external high pass,around 30 years ago, give or take, and I don't recall it costing an arm an leg.

Anyway, in a nutshell (if I've got this right from memory) your RCA outs from preamp will go into highpass/from high pass L & R RCA out to amp and also L&R RCA out to subwoofer.  I do not remember at what frequency mine was preset to roll the bass off to the sub.  Mine has a treble level adjustment (speakers) and bass level adjustment (sub).

Besides allowing you to use RCA cables to hook up sub, other benefits are freeing the amp up from as much bass as it was  powering before, which also frees up the speakers from trying to reproduce as much bass as they were before. 

I remember at the time immediately hearing things sound much more dynamic with the smaller stereo tube amp (Cary SLA70) I was using at the time.

I also remember a dealer basically turning up his nose at the notion of using one.  "Another crappy box," he told me.  But he didn't use the term 'crappy.'

I quit using it when I became a 'purity of signal' snob and also because I bought bigger amps and they seemed dynamic enough without it, and also because I had acquired equipment with truly balanced circuits that I wanted to use and the M&K high pass only has RCA ins and outs.

Like everything, pros and cons.  But long story short--that would probably solve the blowing fuses issue you are having.

 

Can't you go from the R & L amp outs to the subs and subs usually have outs for the main speakers.

@noromance

that’s what I did, as shown on pics. Should I just wire left to left, right to right as on picture #2?

@immatthewj

 

most everything I have is crappy (except for my TT and bookshelf speakers). Just one RCA out from preamp. I can use a splitter

no sub out from amp

I can’t buy another component, I have to make what I have work.

It’s a 45 year old amp with the tightest binding posts. (That’s why it took 90 minutes, to group and isolate naked wires in 1/20 inches of spaces.)

I can’t buy another component, I have to make what I have work.

I gotcha; I totally understand.  

But I am going to ask anyway if I am understanding this correctly:

Just one RCA out from preamp.

You are saying just one pair of RCAs (L&R) out from the preamp (going to the amp), correct?

That's what I interpreted, anyway, when you said you had no sub out in your preamp.  I understand what you were saying about not buying another component, but I'll clarify what I was saying anyway:

the highpass filter goes between the pre and the amp.  In other words, that one pair of RCAs out to the amp now goes IN to the highpass filter.  (Highpaass filter then rolls off the bass, but I am not sure at what frequency).  There are two pairs of RCA outs in the highpass filter, and the pair with the bass connects to the subs (although in my case it was sub as in singular), and then the pair with the remaining treble goes to the amp.

 

Grizzly, even though I know what you said and I respect that and I understand, since a pic is theoretically worth a lot of words, here is what my high pass looks like. I am only posting this as it may clarify my explanation. And A’gon may not let it be posted . . . I’ve never had a lot of luck posting links here.

https://www.ebay.com/itm/116023312749

To post a clickable link: On the toolbar just to the right of the emoji click the chain link, put the link in the URL window. If you want to name the link, put the name in the Display Text box then click ok.

https://www.ebay.com/itm/116023312749

It worked!! Thanks, @dill !!! I am diagnoseably computer illiterate, but now, thanks to you, a tad bit less. That’s the second thing I’ve learned in the last ten minutes!

On edit:  that is transformational!

thanks @immatthewj that makes sense.

I do have this

except that it does not work https://outlawaudio.com/products/icbm.html

I bought it for $120 and it came busted and I can’t send it back. (Being poor stings twice - when you can’t buy things and then when you finally buy something cheap and shady and get scammed) But why should I complain, having two subwoofers is not a basic need smiley

And yes, my preamp has only one RCA out pair

Hmmm, I guess "Outlaw" was an appropriate name for it.

Did you get your subs working yet, via speaker wires to sub and out of sub?

I just re-read your OP, and out of curiosity, what is your second sub?

And your original (first) sub?

And also, since I am ASSUMING that your original single sub was hooked up and operating via speaker wire connections, is it at all possible that a problem is existing with the second sub that is causing the fuse to blow?

this looks also cool (but $ already too high

Okay, so that’s a low pass filter, which, if I’ve got this right and your sub is the same as mine, is the adjustable part that sets where the frequency that the sub reproduces will be cut off at..

"A low-pass filter (LPF) is a circuit that only passes signals below its cutoff frequency while attenuating all signals above it. It is the complement of a high-pass filter, which only passes signals above its cutoff frequency and attenuates all signals below it."

"I hooked them up was I went from the SUB SPEAKER OUT from both subwoofers"

You want to go to the sub INPUT not the output. Unless that was a misprint in your original post, using the output on the subs would blow a fuse.You would be directing the sub amps back into your stereo amplifier.

Grizzly, I am confused (but that doesn’t take much) picture 1.

I’ve never hooked my sub up via speaker wire, but I save all my manuals, so I just went to my M&K sub manual and looked at it, and it appears as if they are saying to hook up as you show in picture 2.

Left + & - out of amp goes into left + and - i "from sub" inputs in subwoofer.

Right + & - out of amp goes into right + & - "from sub" inputs in the sub.

At the sub, in my manual, it shows two sets of (one for L and the other for R) TO SPEAKER outs.

I am not understanding how you wired it in pic one.

I could scan the diagram in my manual and attach it to a reply if that would help?

But on edit: being computer illiterate, I don’t see how to include an attachment on this site?

 

@immatthewj I understand your description. It makes sense. What I did was duplicating the output (that I used to have for ONE sub). I should just treat the subs and the speakers, as left and right channels. 

I tried. Few bucks of fuses are not the end of the World. I will try your suggestion tomorrow.

Grizzly, let me add two more things:

what I described in my last post was a diagram showing how to use only ONE sub.  However, I truly do not think that it would change if you were using two subs, except that you would not use both left and right ins and outs from one sub--in other words left sub would use only left in and only left out/and then the same for the right sub to right speaker.  Sorry because I know that this is way more than obvious, but I felt the need just in case.

The second thing is my manual shows a second option with speaker wire, BUT this is for amps or receivers that feature an OUTPUT 1 (for speaker wires) and ALSO an OUTPUT 2 (for speaker wires).

I am going to assume that you do not have that (I don't think I've ever owned anything that had that) but just in case:  that diagram shows OUTPUT 1 (speaker wires)  hooked to L & R speakers as per the usual way, and it shows OUTPUT 2 (speaker wires) hooking to the speaker wire inputs in the sub.  And note that in this configuration, the speaker wire outputs from the sub are NOT being utilized.  And again, this diagram is for only ONE sub, but if two were being utilized, obviously one sub would connect to L and the other to R. (Even though I know how obvious that is.)  So I am pretty sure you don't have two sets of speaker wire OUTs in your amp, but in the way way way off chance that you do, there is also that option.

Few bucks of fuses are not the end of the World.

Hopefully you have not been using fuses that are orange, purple, or blue?

@immatthewj 

you are very thorough and kind and helpful. I have exactly what is on the photo I included.

It's this model. 

https://www.polkaudio.com/en-us/product/home-speakers/subwoofers/psw-10/112479-new.html

it has RCA in, LFE inputs too. (And they sound great to my ear)

Just did this with my new (to me), no frills, Don Sachs integrated.  +1 noromance, Pic 2.  Worked like a champ.  Pic 2 preseves any notion of stereo for the subs.  In my case, one sub didn't have Hi-power inputs so I had to use a speaker to line-level converter.  EZ PZ.  

Griz, I am intrigued by those Polks. My M&K is ancient . . . it was the piece of gear that started me down this road to hell. I think that was near the end of ’93, either that or very early in ’94. M&K (apparently at least at that  time) didn’t believe in fancy power cords. Hardwired from the amp section is not much more than lamp cord with a two blade plug. I have no doubt that my sub is the weakest piece of my system, and it has been for some time. As I typed, I am intrigued by those Polks.

I do need to correct something I typed about the high pass filter. At least the one I put a link to a picture of. I said it rolled off the bass to the sub. That was incorrect--a low pass filter would roll off the bass to the sub. That high pass sends the full signal from the the preamp out to the sub, where the frequency is then adjusted at the low pass that is integral to the sub.

(I got curious so I dug out the high pass filter instructions.) So what the high pass filter therefore must do (although I cannot find this spelled out) is to roll off the bass FROM the preamp TO the amplifier (and therefore the speakers). But, I am not sure at what the frequency cut off is that it allows to the amplifier. But the idea is to provide a cleaner separation of bass between the speakers and the sub(s).

Oops! So I’ll insert an edit: I just did some searches only to satisfy my own curiosity, and evidently that particular high pass filter is set to allow 80hZ and up FROM the preamp To the amp (and therefore the speakers).

Not that this is applicable to you; however, since I typed it and got it wrong but can no longer edit, I just felt the need to correct that part. Ramble on. . . .

 

 

 

 

thanks @akgwhiz!

@immatthewj I am sufficiently confused as I try to visualize it with my limited options but at least I am positive you know how it works on your end. My setup - if my Outlaw had worked I think it would be

                                                         sub (RCA)
                                                        /
source -> preamp - bass manager
                                                        \
                                                          amplifier
                                                                         \
                                                                          bookshelf speakers

I didn’t read every post but if not already recommended, why not use rca splitters from your single rca output then let the internal amplifiers in your powered subs do the work? Parden please, if I am somehow missing the issue.

@mitch2 yes I did mention the splitter. How many splitters would I need for two subs?

The purpose of having both channel inputs on the sub is so that they can be summed to mono. If you are using the two subs adjacent to your left and right main speakers, you could consider left channel to left sub and right channel to right sub. If they are not adjacent to the mains, you should run both channels to the subs and sum to mono.

Regarding blowing fuses, I suspect the fiddly insertion of all those wires into your power amp resulted in a loose strand that was shorting to the adjacent connector. Have a close look. You might be better to make a y connector, assuming you are using standard speaker wire. A short length of wire, then solder the mains and sub leads pos to pos and neg to neg, using shrink wrap or electrical tape to insulate the connections. There is very little current flow into the high level sub inputs, soyou are not overloading the single y connector wire to the amp. Hope this helps.

@audio_guy_uofw

yes it helps thank you. I have about 5 millimeters between the speaker binders and my speaker wires are thick. I could look for thinner speaker wires. 

I sold my beloved Marantz amp for this reason, impossible speaker binders, swapping speakers was an afternoon long activity. 

I am giving it one last try, hopefully it will leave the fuse alone.

How many splitters would I need for two subs?

You need a splitter for each channel, so two in your case.  I linked AudioQuest splitters but if you check lower down the linked Amazon page, you will find no-name brands for about half the AQ version.

The splitter plugs into your rca output and then you run one rca cable per channel to the amplifier powering your main speakers and one rca cable to the low level input of each powered sub.  This approach would give you stereo imaging for your subs, i.e., one sub for each channel, which is a common approach when running two subs.  In that case I would position one sub somewhat near each main speaker. 

Summing the sub signal is a typical approach used when running only one sub, and sometimes when running a swarm of subs (more that two) throughout the room.  

@mitch2 ok so in dummy terms, red to red, white to white from the preamp?

A single line to each sub?

@deep_333

beautiful! thank you! smooth and buttery :) I owe you a beer.

And you can actually write with a pen nicely, I give up after three words, it just looks like I had a stroke.  

@grislybutter

Yes or, if you prefer, left preamp out to left amplifier input and left subwoofer line-level input, and right preamp out to right amp input and right sub line-level input.  Good luck.

I thought from your earlier posts you had a preamp output to your power amp, and could use a Y cable to split into outputs for amp and subs. 

@immatthewj I am sufficiently confused as I try to visualize it with my limited options but at least I am positive you know how it works on your end. My setup - if my Outlaw had worked I think it would be

Sorry, @grislybutter , for the confusion. Although I understand and respect that this is not an option you presently want to consider, I still feel compelled to do a better job of explaining it.

Okay, your L & R RCAs outs FROM preamp would go TO the L & R RCA ins in the high pass filter.

The high pass filter would have TWO PAIRS of RCA OUTs.

The high pass filter would send the full frequency signal to the subwoofer via the pair of RCAs designated subwoofer,

however, the high pass would only send an 80 hZ and up signal out of the pair of RCAs designated speakers, and these RCAs would connect to your amp. So if you think about it, now your amp is only reproducing 80 and up, and therefore your speakers are only trying to reproduce 80 and up.

Back at the sub, which is getting a full frequency signal from the high pass filter, the user would probably set the adjustment (and this would be the low pass filter that one would adjust on the sub) to 80 or 85 hZ to start with. So what one would be doing, in theory if it was a clean chop off of frequencies, is having the sub reproduce everything exactly under 80 hZ and having the speakers reproduce everything exactly above 80 hZ. In a perfect world, there would be no overlap between the sub and the speakers. (And also, even in a less than perfect world, both the amp and the speakers are now free of the work of trying to reproduce frequency below 80 hZ which should free them up to do a better job on the higher frequencies.)

But they tell me it is not a perfect world, and it is not a clean EXACT cut off at 80 hZ and therefore the adjustment at the sub (the low pass filter) needs to be played with and tweaked a bit, usually starting at around 85 hZ.

Hopefully I was able to clarify that & clear up any confusion I may have created.

However, much simpler, as @mitch2 just said, would be an RCA ’Y’ splitter at each RCA out of your preamp (L & R). From left one RCA would go to left RCA IN of your amp and also to the RAC IN of your left subwoofer/and then the same for the right.

 

 

@mashif my bad - I do have an out from my preamp. I call preamp out from integrated amps - but you are right. So yes, that’s a good suggestion

 

@immatthewj thanks for the clarification. It wasn't your fault, I am easily confused. Your explanations are always very thorough.

I am looking up Y splitters now on Amazon.

@immatthewj thanks for the clarification. It wasn't your fault, I am easily confused. Your explanations are always very thorough.

I am looking up Y splitters now on Amazon.

@grislybutter , I've actually used 'Y' splitters for something I was doing with my HT setup (way back in the days of Dolby Prologic when I had a HT set up) and I don't know why I didn't mention that before.  Something about 'Y' splitters from preamp seems intrinsically impure to me, but thinking about it, it cannot be as impure as "another crappy box" (with a pair of pots) and an extra pair of interconnects that were not there before.

And also, just out of curiosity I feel compelled to ask, did you try speaker wire out to sub and then out to speaker on both the left and right side?  (In other words, treating each sub/speaker as an extension of each other?)  Just wondering if you did and how it went. . . .

@immatthewj I have the same feeling about Y splitters, not very audiophile-ish. But - also cheaper than a box.

I have not tried "serializing" subs and speakers. I want the signal to go from my amp directly to the speakers to somehow justify my semi-decent Morrow Audio speaker cables. (In the same time, at my level, speaker cables don't matter)

 

Oh, I forgot to mention that it's electrically equivalent (per sub company chief product guy) to do the same wiring from the speaker terminals to the subs if that's logistically easier.  Less wire, less clutter in rack.   

https://www.transparentcable.com/products/rca-y

https://soundapproach.com/wireworld-luna-8-luiy-audio-y-adapter-cable-single.html