speakers and cables

Why not just use a Y cable on your preamp outs?

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.

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

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. . . .

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.  

@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)

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

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

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.

@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.

@jtcf yes it was a typo, I went to the sub INPUT as shown on the pictures

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?

"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.

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."

this looks also cool (but $ already too high

https://shopgoodwill.com/item/203575181

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?

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 

And yes, my preamp has only one RCA out pair

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!

high pass filter

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

Pic # 2

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

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.

@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.)

@noromance

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

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

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.

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. 

@akg_ca

I am using the high level inputs.

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. .

thanks @rhg3!

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.

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.

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.