beely Posted July 14, 2014 Share Posted July 14, 2014 Hi. If I daisy-chain a 4 ohm bass bin to a 4ohm top ie, amp output in to bass bin, out of bass bin in to top, is this wired in series or parallel? My feeling is they are wired in series, thereby creating an 8 ohm load. One of these connected to each of two channel outputs on the amp, wires them in parallel, thereby reducing the load to a still-acceptable 4 ohms. The reason I ask is we have just bought a new amp to power our PA. It's a QSC GX7. The manual is a bit ambiguous regarding speaker connections or at least it is to me. I contacted QSC to ask for advice and the tech guy who got back to me said it was unlikely that they were wired in series, more likely parallel. This would create a 2ohm load which is not so good. It might be the case I didn't explain the set-up very well to him and this was why he reached this conclusion. I will get back in touch with him, but I thought I would give Basschat the opportunity to share its collective wisdom. Cheers for any help or advice. Beely Quote Link to comment Share on other sites More sharing options...
HowieBass Posted July 14, 2014 Share Posted July 14, 2014 Usually when you have two inputs on a speaker it's a parallel connection so taking one output from an amp to the speaker and then linking another speaker to the first puts both cabs in parallel. The amp must not have lower than a 4 ohm load per channel, so that's two cabs in parallel each of 8 ohm. Quote Link to comment Share on other sites More sharing options...
hamfist Posted July 14, 2014 Share Posted July 14, 2014 Yes, HowieBass is right. Cabs and connections like these are virtually always wired in parallel. Quote Link to comment Share on other sites More sharing options...
Dad3353 Posted July 14, 2014 Share Posted July 14, 2014 [quote name='beely' timestamp='1405366850' post='2501325']...Cheers for any help or advice...[/quote] Good evening, Beely... Not enough information to be really useful, I'm afraid. What units are these cabs. (make and model...)..? With no further info to go on, I'd say that these will give a 2 ohm load to the amp. There are, however, sub cabs with built-in crossovers, designed for being connected exactly as described (amp to sub, sub linked to top...). Normally, subs wired this way would have this connection method marked on the back plate. There are also sub cabs using 4-wire speakon cables, which use one pair for subs and the second pair for the tops. Again, this should be clear on the back panel. In case of doubt, take the sockets to be in parallel; that's far more prevalent. Hope this helps. Quote Link to comment Share on other sites More sharing options...
beely Posted July 14, 2014 Author Share Posted July 14, 2014 Hi guys. Thanks for the replies. Basschat is such an education. The bass bins are Peavey Mega Subs which do have a built-in crossover. There are four jack sockets on the back, two are marked "Full range". I would presume these are wired in parallel. The other two sockets are marked "Bi-amp Lo" and "Hi out" These will be the ones connected through the crossover I suppose. The plate on the back is extremely worn so I'm afraid I can't supply any other relevant info. Thanks again. Quote Link to comment Share on other sites More sharing options...
Dad3353 Posted July 14, 2014 Share Posted July 14, 2014 Beely... If you're running these from a normal 'stereo' power amp, I'd connect each channel of the amp to the 'Full-range' jack on a sub and link the 'Hi Out' to its top; job done. The amp will 'see' 4 ohms. Subject to correction, completion and/or contradiction from others; hope this helps. Quote Link to comment Share on other sites More sharing options...
Monckyman Posted July 14, 2014 Share Posted July 14, 2014 Dad has it correctly. 4ohm load wired as suggested above. This gives full range to the subs up to the internal x over frequency (guessing on PV 120hz) and above that gets put out the Hi out socket. On a QSC GX7 that's 1000 watts per side divided over the two cabs so 500 watts each. I have a GX5 and it's a nice sounding versatile amp. Enjoy! Quote Link to comment Share on other sites More sharing options...
beely Posted July 15, 2014 Author Share Posted July 15, 2014 Hi. Once again, thanks for the helpful advice. I had a bit of a sleepless night over this. I'm glad I read your replies before I left for work this morning. They put a bit of a spring into this Postie's step. Monckyman: One of the reasons I was attracted to this amp was indeed the versatility. The variety of input/output options will be very useful I'm sure. Cheers for now, Beely Quote Link to comment Share on other sites More sharing options...
rmorris Posted July 15, 2014 Share Posted July 15, 2014 Have to say I'm confused by the description of the setup. A diagram of some sort would clarify. tbh most good quality modern power amps should be okay with a nominal 2 ohm load but fidelity might be compromised. Quote Link to comment Share on other sites More sharing options...
Dad3353 Posted July 15, 2014 Share Posted July 15, 2014 [quote name='rmorris' timestamp='1405449586' post='2502023'] Have to say I'm confused by the description of the setup. A diagram of some sort would clarify. tbh most good quality modern power amps should be okay with a nominal 2 ohm load but fidelity might be compromised. [/quote] Any good..? [attachment=166826:Peav_PA.png] The amp mentioned only caters for 4 or 8 ohms. At 4 ohms, it is capable of 1000w per channel. That's a lot for that Peavey rig. One shouldn't go overboard with the volume levels. Quote Link to comment Share on other sites More sharing options...
beely Posted July 15, 2014 Author Share Posted July 15, 2014 I was working on a diagram to post but you have it covered perfectly. I based the choice of amp on the (incorrect) assumption I would be running at 8 ohms. Given the recent update to my knowledge, I realise that is not the case so I will indeed need to take great care with the volume settings. The bass speakers are actually 500w Eminence speakers, can't remember the model, but they are a replacement for the original Black Widows which were 8 ohm, 250w. I changed them so they would be the same impedance as the tops. If I had changed the speakers in the tops to 8 ohms to match the bass bins, then we probably wouldn't be having this conversation. Cheers for now, Beely Quote Link to comment Share on other sites More sharing options...
Dad3353 Posted July 15, 2014 Share Posted July 15, 2014 [URL=http://www.smileyvault.com/][IMG]http://www.smileyvault.com/albums/CBSA/smileyvault-cute-big-smiley-animated-041.gif[/IMG][/URL] Quote Link to comment Share on other sites More sharing options...
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