Dual 1/4 Inch jack speakers - connections advice

Discussion in 'Patchbays' started by Don't Count The Hours, Sep 8, 2015.

  1. Don't Count The Hours

    Don't Count The Hours Active Member

    Hi shameless quest for advice here - if anyone has 2 cents they can donate it would be very much appreciated.

    Got hold of two weighty PA looking speakers with dual 1/4 inch jacks and no knowledge of their spec or their past and my limited knowledge is at a loss for the best way to utilise them... exhibit A attached below (please ignore the amp above it's not working)

    FullSizeRender(1).jpg FullSizeRender.jpg

    The cable above is TS 1/4 inch - RCA phono on the other end as a friend had some but it doesn't help me much as all I currently have for a working amp has standard banana connector inputs...exhibit B...


    I realize there may be a few issues here but basically I just want to find out the best way to connect the speakers to the amp...and if that's not feasible what amp input would most likely be best for the speakers ( I also realize they're very mysterious and unrevealing)

    Many thanks if anyone can take the time out to help!
  2. dvdhawk

    dvdhawk Well-Known Member

    Hello and welcome,

    Without more details I can offer this free, very general, advice:

    A) Don't EVER plug the 2 separate amp channels coming out of the banana plugs into both ¼" inputs of the SAME speaker cabinet.
    That would burn up the amplifier in very short order. Generally speaking it doesn't matter which input you use, but the other is for running another speaker in parallel (whenever possible and/or desirable) *see B below.

    B) Look to see if the speakers have any clue (usually printed near the input connectors) as to their impedance. Some research online may be in order. 8Ω is probably the most common, but it's best not to assume anything. The amplifier will also have a rating for minimum impedance (often printed on the back of the amp near the binding-posts). You will need to be sure that the speakers by themselves, or in combination do not go below the amplifier's minimum. Despite what may seem logical to most novices, running two 8Ω speakers in parallel results in a 4Ω load to the amplifier. IF that is less than the amp is designed to handle, that would also, you guessed it, result in the amplifier going up in smoke - although not as immediately as in A above. Hooking more than two speakers in parallel would not be advisable unless /until you have an understanding of Mr. Ohm's law and how it applies here.

    C) Occasionally when amplifiers die an unpleasant death, through either normal failure or either scenario above, they can take the connected speakers with them to gear heaven.

    D) Virtually every cable that would have an RCA connector at one end, would NOT be a suitable speaker cable. If you unscrew the barrel of the TS ¼" male, you are likely to see either a spiraled or braided shield going to the S (Sleeve) of the TS connector, and a normal insulated conductor going to the Tip (+). Patch cables such as those are perfect for line level signals. The shield is meant to protect the signal from outside interference and give it a path to earth-ground. But a braided shield is a poor conductor of much higher speaker levels.

    E) What you need are proper ¼" unshielded speaker cables. You can either buy them terminated on one end with banana plugs, or if you're at all handy, you can buy one long cable and cut it somewhere in the middle and put on banana plugs yourself, or insert the stripped ends straight to the binding post. In either case, you would then strip the wires on the cut end and put the conductor that corresponds to the Sleeve to the Black binding post, and the Tips to the Red binding post (of the same channel). The conductors are either going to be color-coded, or if it's flat zip/lamp cord, you may notice one of them has ribs moulded into the cable - it will have to have some sort of marking. You should be able to do this visually unless the ¼" male is moulding onto the cable and cannot be opened. In this case, if you (or someone you know) has multi-meter skills, this would be a good time to bust out said skills.

    F) Lastly, you may want to make sure your expectations of those speakers are realistic. I don't have any idea what you would be replacing them with, or comparing them to, but they look very 'entry-level'. And if that's where you're diving in, that's great, I just wouldn't expect miracles.

    Best of luck!
  3. Don't Count The Hours

    Don't Count The Hours Active Member

    Mr Hawk the advice is very much appreciated and helped my understanding of the situation a lot...

    And yes not expecting wonders from them just need something loud for an event..I'll search out some ¼" unshielded speaker cable. Thanks again.
  4. Boswell

    Boswell Moderator Distinguished Member

    From your photo, those look like Allan-Gordon loudspeakers. A-G ceased producing hardware many years ago, but it looks from a quick internet search as though they may still operate rehearsal rooms in Walthamstow under the name of Allan Gordon Studios.

    You need 1/4" (6.35mm) TS plug to banana plug loudspeaker cables. This sort of thing. BTW, it's easy to change one of the jack sockets on the back of the speaker to a Speakcon connector. That opens up many more sorts of speaker cables.
    Don't Count The Hours likes this.
  5. Don't Count The Hours

    Don't Count The Hours Active Member

    Lovely, thanks Boswell - interesting to know their background if that's correct...1/4 jack to banana plugs seem to mostly be from other countries on ebay so will try and attach my own. Thanks for the help both much appreciated.
  6. Don't Count The Hours

    Don't Count The Hours Active Member

    Hello again - when Hawk says unshielded...does that mean shielded won't work or as line level will just be bad quality? I can only find shielded on the high street...
  7. pcrecord

    pcrecord Don't you want the best recording like I do ? Well-Known Member

    From PA to Speaker cables don't need shielding because of their high power. Don't you ever use a guitar cable as PA-Speaker cable. The size of the wires in a guitar cable are so small they'd probable burn at high volume of a PA... Shielding is important when the cable transport a low level signal, like a mic, a guitar or even Line level (record level) like a tape deck or cd player.

    You can make your own speaker cable with 14 or 12 gauge stranded cables (like lamp wire but bigger) the size would depend on how many watts the PA can produce.
    Don't Count The Hours likes this.
  8. Don't Count The Hours

    Don't Count The Hours Active Member

    Thanks for the reply pcrecord...Sorry might have got confused with line-level talk...

    Point was the shielded vs unshielded and if shielded would actually work or not.

    The below 1/4 inch to 1/4 inch speaker (shielded) cable is what I can get in the shops here cut in half, seperate and put directly into the amp - would this work in theory?

    Thanks again all.
  9. Boswell

    Boswell Moderator Distinguished Member

    You should ask for "speaker cable". If you look at the photo in the Ebay listing I linked to, the wire in that is thick, stranded copper cable with a plastic cover. Two conductors with their plastic insulating covers run side-by-side, and that's the connection for one loudspeaker. Maplin has over a dozen different speaker cables listed in their on-line store.

    If you can wire one end of this type of cable to a TS jack plug, at the other end you can get away with using stripped conductor ends screwed down under the binding posts (which also serve as the 4mm banana plug connectors). Make sure you get the polarity the same on both leads.
    Don't Count The Hours likes this.
  10. dvdhawk

    dvdhawk Well-Known Member

    Did you intend to put in a link to a shielded speaker cable?

    Speaker cables are not generally shielded except in very specific cases to cut down on extreme cases of crosstalk and in the presence of strong radio interference. But to be clear in addition to a shield (either foil wrapped with a drain-wire, spiraled wire shield, or braided shield) this cable would have 2 conductors, preferably 14 or heavier gauge wire ( also counter-intuitively heavier gauge = a smaller number ) .

    An instrument cable will technically function as a speaker cable, but VERY poorly. We'll let the fine folks at ProCo with their Speaker Cable Q&A have a run at the details, as I'm sure they'll do a better job explaining it. Even with proper speaker cables - the longer the cable, the higher the loss. Compound that with the wrong type of wire and you quickly lose a large portion of the output of the amp.

    Sir Boswell can surely point you in the direction of other local/regional vendors other than Thomann who have proper speaker cables ¼" TS to ¼" TS. I don't see any already fitted with banana plugs at one end and ¼" TS at the other end listed at Thomann, but Maplin sells banana plugs they say are "ideal for a pair of speaker leads".
    Don't Count The Hours likes this.
  11. Don't Count The Hours

    Don't Count The Hours Active Member

    Thanks for the patience I did mean to link the below...the label says shielded which is what confused me so is this not suitable to cut in half and strip the ends?

  12. pcrecord

    pcrecord Don't you want the best recording like I do ? Well-Known Member

    I checked your link.. I find it a lack of seriousness to not specify the gauge of the wire.. According to the size to the connector ratio.. I don't think it's more than 16. Would be ok for low level PA but not for high wattage.. Anyway I'm just guessing because they don't say..

    Something like this would be a more serious choice :
    Try their cable finder : http://www.sweetwater.com/shop/cables/finder.php

    BTW I'm no sweetwater seller.. just find they are a good reference ;)
    Don't Count The Hours likes this.
  13. Don't Count The Hours

    Don't Count The Hours Active Member

    Yes they're bottom of the range tbh but I'm just trying to get something sorted that works for the moment and cheap as I'm not even sure the speakers work at this point.

    Terrible picture apologies but the label says 'fully shielded low noise cable' and 'designed specifically for speaker use' which confused me...

  14. pcrecord

    pcrecord Don't you want the best recording like I do ? Well-Known Member

    Well you seem to have made your mind and since the PA doesn't seem to develop a lot of Wattage, you should be ok..
    Don't Count The Hours likes this.
  15. Don't Count The Hours

    Don't Count The Hours Active Member

    If this one will 'do the job' for the minute then I'll get it tomorrow, cut in half and strip the ends - just wanted to clarify the shielded thing...will update.

    Thanks again for the patience and advice - was at a total loss yesterday.
  16. dvdhawk

    dvdhawk Well-Known Member

    I can see why that would be confusing.

    If you decide to go that route I'll be curious to hear what you find, in terms of a shield, when you cut the cable in half. It's certainly possible it's shielded, but I believe it's as likely that the packaging is incorrect - losing something in translation.

    For wire reference, the 1.5mm cores they refer to equal somewhere between 14AWG and 15AWG if they're referring to diameter - and between 15AWG and 16AWG if they're giving the area of the cross-section.

    Again, I wish you the best!
  17. Boswell

    Boswell Moderator Distinguished Member

    The link you gave is for a 6m length of cable. If your intention is to cut this in half, strip the cut ends and wire them to the binding post terminals on the amplifier, then 3m for each speaker lead feels restrictively short. You seem sold on this particular cable, so I would get two cables and cut the jack plugs off one end of each so at least you have 6m apiece to play with when positioning your speakers.
  18. DonnyThompson

    DonnyThompson Distinguished Member

    If you plan on cutting the cable, make sure you keep track of your +/- ... You may want to consider marking one side of the cable's outer coating with a silver colored permanent maker or something, so you know which is which.

  19. dvdhawk

    dvdhawk Well-Known Member

    And while we're throwing out alternatives, if this is a first step toward possibly buying other amps or speakers, you may consider buying the ¼" to SpeakOn cables and removing the SpeakOn connectors for now. (easily removed and/or reinstalled with a screwdriver) The SpeakOn is a vastly better connector than ¼" phone jacks and doesn't require any soldering. It will cost a little more, but it will money better spent if you can swing it.
    pcrecord likes this.
  20. Boswell

    Boswell Moderator Distinguished Member

    That's a great idea of Hawk's. Furthermore, it promotes the step I mentioned earlier about changing one of the jack sockets on the rear of the speakers to a Speakon connector. My memory of doing this years ago on a set of A-G speakers is that (surprisingly) the Speakon connector fitted in the same size hole as the jack socket. You choose the slave jack socket (not the one with the wires going off to the crossover network) and unsolder the wires from it, then replace it with the Speakon connector, and finally re-solder the wires to the Speakon connector terminals.

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