Best Sounding Adapter - Making RCA into Banana or Spade? Thanks!

Maybe I'm thick, Drinking my first cup of coffee today with Boz Skaggs, but I think we need more info what you're trying to do.

Jerry

If for speakers, bare wire is best. 

The cable will connect an integrated amp (banana or spade) to a subwoofer (RCA).   The cable is RCA both ends.  I want to avoid cutting off the RCA at one end and so use a banana / spade adapter. Thank you for your help :-)

STOP. 

You can't run a power signal to a line level input.  You'll break something. 

Many subwoofers can use the amplified signal but they have circuitry to deal with it.  The RCA on your sub is for a line level signal--not amplied.  Banan plugs are used for amplified signals. RCA for line level.  That is to prevent just the thing you are suggeting doing.

Most recievers have a "sub out" RCA.  this is for home theatre.

I don't use subs for music but I know REL subs are designed to handle the amplfied signal (and then send it on to the main speakers).

Jerry

You could get a line out converter if you want to take speaker level signal; Or a line out attenuator, fixed or variable, if you want to take signal from line level. Try Amazon or Crutchfield.

Since I'm the one that said "stop" and you may be wondering if @lanx0003 knows what he is talking about (hey, we're just 2 randos on the internet, right) I should say that I fully agree with what he says.  there are also actually DIY options to build your own connection but the line out adapters are not expensive.  I'd build my own only if I thought I could build a better one (which I almost always do believe, but many DIYers don't; they are trying to save $). 

Jerry

Why not just just use  RCAv Y connectors from the integrated to the sub?

In my case, I was doing that from the beginning. However, it turns out the amp pumps too much power into my sub. You can tell right away because it leaves no room for volume adjustment on the sub, and it doesn't sound right—it just rumbles. That's when you need the aforementioned attenuator.

The use of Line out Converters (LOCs) is well established in autosound, as factory head units lack preamp outputs. I use a Stinger LOC in one of my systems to hook up a pair of subs that lack speaker level inputs. While other options may exist, this is surely one.  Why doesn’t OP say exactly what they are working with and what they are trying to do with it?

I'm not a subwoofer guy. Is there a sub with RCA inputs on the market that is designed to be connected to speaker output connections (that's a lot of current for an RCA type)? I would recommend that you send an email to the sub maker include all the information on your amplifier, make, model, power output, speaker impedance, type of terminations, etc. There is a possibility, and I hesitate to mention it for liability reasons ;) but is your sub a powered unit specifically designed to use the tape monitor outputs on your amp, or a line-level output? Perhaps if you give the forum information on make and model of sub and amp, someone here has saved the instruction book, or go to hifi engine for user and service manuals. The amount of current in a line-level, or RCA circuit compared to the current from a speaker output from an amplifier, is like the difference between a yard sprinkler and Niagara Falls. Niagara Falls, very dangerous, lawn sprinkle safe for kids and dogs. Please contact the sub maker or the place of purchase.

To do this, you need a "preamp out" section on the back of your amp.  Otherwise it is a no go.

Line level converters are super simple to build even with super basic soldering skills. Get a little plastic box off Amazon, a set of speaker binding posts (4 total), a set of female rca connectors (2ea), 1K 1/4 watt resistor (2ea) and 10K 1/4w resistor (2ea) and a pinch of wire. Drill your holes in the case, mount your rca and binding posts, then solder the 1K resistor across ground to + on the rca. Next wire the - binding post to the ground rca, then finally connect the 10K resistor from + binding post to + rca connector. Taaadaaa, you built a fantastic line level converters. Basic binding posts and rca will give great results, but upgrading to WBT or my favorite being KLE connectors, you’ll get even better performance. All in all, basic setup should be $30 and an hour of time. When I ran converters, I even did away with the binding posts and just hot glued the speaker cables into the case and wired straight to the rca.

Also on these, since it’s all 1/4w resistors, there is no extra power draw from your amplifier so unless you’re running a flea watt amp, there’s no worries about headroom. And if you need to lower the signal even further, just up the value of the + leg resistor from 10K to 15K, 20K etc until you get the value where your sub blends using 40-50% volume. I tried loading a photo but it's not wanting to cooperate. Sorry.

Hope this helps,

-Lloyd

No dialogue here.

All I hear are crickets😂

In my car stereo days, we referred to these genercially as "high-to-low-level adapters".  Speaker level in.  Line level out.  Depending on your level of persnicketiness, you can find these at a variety of price ranges.

Another consideration here is that you have a single RCA cable and your amp has left AND right channels.  While bass is generally summed to both channels, you can take your pick of left OR right. You may want to look for a "summing" adapter if you want to make sure you capture all the bass information.  Probably overthinking this a bit, but just throwing it out there IF it matters to you.

As far as termination on the amp end is concerned, it may depend on you amp.  IF your amp has speaker A and B connections, then connecting to speaker B will give you a wide range of connection options.  IF your amp has speaker A only, then. you will be joining other speaker connections which may make the connections more challenging.  If you are using bananas, for example, adding more bananas is certainly above my pay grade.  But, generally, raw wire is best, but takes a little more time a patience to get it right.

Thank you to everyone who has kindly shared their thoughts - much appreciated!
I’m certainly learning and appreciate the insights and caution too. My rig is:

Integrated Amp - Unison Research "Unico" (Gen. 1 with the IR remote).
It has speaker outputs and a "Tape" RCA output.

Home Theater / Audio Tower Speakers - Definitive Technology BP2000.
Bipolar, so same speakers back and front, plus a 13" 300W sub-woofer.
Each tower has three pairs of binding posts - ’Low,’ ’Medium’ and ’High.’
The ’Low’ / sub woofer also has the RCA input option.

Currently I use one set of speaker cables from the integrated amp to the ’Middle’ binding posts of each speaker. Then jumper cables from the ’Middle’ to the ’Low’ and ’High.’

Q1. Can the "Tape" RCA output connect directly to the sub-woofer RCA input?

Q2. If "Yes" to Q1, is this typically better sounding than the jumper cable set up?

Q3. Does bi-wiring or tri-wiring speakers sound better than all the above?

Thank you in advance for your thoughts! :-)

If I accurately understand your question, you wish to connect an RCA (line level) to permit use of speakers terminated with banana plugs. May I suggest using a Fosi Audio TB10D? I purchased the unit on Amazon for under $70. It is a simple mini power amp equipped with volume, treble, bass control, and a 32V/5A power supply. I have a JVC VHS/DVD player and  inserted the RCA connectors and speaker banana plugs into the TB10D to power a set of 4 ohm MartinLogan towers.       

@vinylfun 

Let me take a shot at your questions:

Q1: the tape out is a fixed output, meaning that it does not change with volume.  Yes, it could connect to your sub, but it would be rather tedious to adjust the volume on the sub each time you adjusted the volume on the amp.

Q2: answered with Q1?

Q3: This group is all over the place on the subject of bi-wiring.

Looks like we're circling back to a high quality high-> low adapter?