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New member Username: ZagfuchsPost Number: 1 Registered: Jan-13 | I have a buddy that is wondering what his options are for hooking his speakers up. He has a one channel mixer amp that is for running nine 8ohm speakers. He's not really sure how, but the final ohmage right now is reading 4.8, any help would be greatly appreciated. |
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Bronze Member Username: OrnelloPost Number: 44 Registered: Dec-12 | Perhaps more details could be useful. |
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New member Username: ZagfuchsPost Number: 3 Registered: Jan-13 | What details do you need? |
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Bronze Member Username: OrnelloPost Number: 46 Registered: Dec-12 | Gosh, you know, stuff like what speakers and amp are involved. Specifics. |
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New member Username: ZagfuchsPost Number: 4 Registered: Jan-13 | Speakers are nine Bose 301, amp is a Sunn sr6520p, it is a one channel mixer amp that is 2 ohm stable. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 17627 Registered: May-04 | . "any help would be greatly appreciated" Help doing what? What's the end result you want to achieve? 4.8 Ohms is not a completely impossible load. However, it's unlikely the impedance doesn't drop beneath that point at some frequency. So, what does your friend want to do? Raise the overal impedance load to make the system more stable? Or, lower the overal impedance to gain some extra watts? Series/parallel conn}ections of eight speakers can be difficult to compute. Maybe this willl help; http://search.yahoo.com/search;_ylt=Awrj4kGkr.hQrmYA3hRhxrF_?p=series+parallel+s peaker+connection&fr=ush-mail&origin=us.mc1849.mail.yahoo.com&pqstr=parallel+spe aker+connection . |
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Bronze Member Username: OrnelloPost Number: 47 Registered: Dec-12 | I don't think it will fly. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 17631 Registered: May-04 | . Amazing! You don't even know what he wants. Why don't we wait to see if he even comes back? |
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New member Username: ZagfuchsPost Number: 5 Registered: Jan-13 | He wants to make it more stable, right now its set to where the volume is only able to be turned up one notch before its loud enough, not much play room. He thought it should be running at a higher ohmage, so he was wanting to know what kind of options were best to run nine 8 ohm speakers. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 17634 Registered: May-04 | . If he wants the system to be more stable, he needs to either minimize the number of speakers he hangs on a single amp channel or change how he goes about such a connection. A correct and least expensive thing to do would be buy a stereo amp - or another mono amp - and make parallel/series connections which maintain a stable impedance load on the amp's outputs. This is still a make shift, rigged up solution since series connections will direct most of the amplifier's current (amperage) - its "power" - to the first speaker system in line and then what's left will have a disproportionate amount of power directed to its voice coil and so on down the line. Ultimately some speakers are going to have considerably less available power which will create uneven sound distribution if this is a system with speakers placed around a listening space. But it is rather cheap to accomplish, if that's what you're after. The better choice is to have the amp connected to a transformer/autoformer type distribution network. The store you shop in probably has a 25 or 70 Volt distribution system for the numerous speakers located throughout the space. Such transformers are relatively inexpensive. Their downside is they represent a highly inductive load on the amplifier. A good many power amps are not going to survive being fed to a highly resistive and inductive load and you'll destroy the amp by trying. Most amps that are suited to a 70Volt distribution system have less than stellar sound quality. They are intended more for intercom and background music systems and typically run in a class B or class C configuration. The better alternative, IMO, would be a system which uses autoformers. Autoformers can be arranged in several ways depending on the system configuration but their main advantage will be the amp always sees the impedance load you set up with the autoformer's switches. A constant load, however, does not mean an evenly powered system in that each group of speakers will still have to divide the total wattage of the amp between them. Sooner or later you'll run out of adequate power to drive the system and either less speakers per amp or more amps per speaker grouping will be required. But an autoformer based distribution system will ensure the amp's safety in the face of what would otherwise be overwhelming load requirements. Why does you friend have eight speakers connected to a single channel amp? . |
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Bronze Member Username: OrnelloPost Number: 53 Registered: Dec-12 | As I said, it won't fly. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 17643 Registered: May-04 | . But we'd all approve of the job if you did. Transformers/autoformers are how the pro sound guys do the job. Ornello wouldn't know anything about that. http://www.bing.com/search?q=70+volt+sound+distribution&form=AARTDF&pc=MAAR&src=IE-SearchBox Ornello is a poorly informed blowhard who thinks he has all the knowledge and everyone else is stupid if they do not bow to his opinions - the crazy uncle you intentionally avoid at family get togethers. Ignore him. . |
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New member Username: ZagfuchsPost Number: 7 Registered: Jan-13 | Thanks for your help Jan, I'm going to try and explain this to my buddy and see what he says. His setup is two speakers for front left, two for front right, one for front center, two for rear left, and two for rear right. Plus a sub, but that's a different amp. He used to run it on a 5 channel receiver, but it died. The amp he had on hand was the one channel, so that's what he's trying to make work, he's not real big on buying new stuff. Before, each pair in each corner was wired together to 16 ohms on each channel. Now he's running all nine speakers into one channel. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 17649 Registered: May-04 | . Trying to make a mono amp do the job of a 5.1 HT reciever isn't going to require transformers. It requires a new 5.1 HT receiver. |
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Bronze Member Username: OrnelloPost Number: 83 Registered: Dec-12 | If he's unwilling to purchase the appropriate product, he's not going to get what he needs. It's that simple. |