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Gold Member Username: MixmastaspigTeam RD, Canada Post Number: 2086 Registered: Sep-05 | Hello, I am looking for a amp to run a 4ohm center speaker as my home receiver (Pioneer VSX-1017TXV-K) is only rated to handle 6-8ohms. I have no idea where I sould begin to look, can anyone provide insight to something decent under $500? Thanks! |
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Gold Member Username: MixmastaspigTeam RD, Canada Post Number: 2087 Registered: Sep-05 | Specs on center channel Max Amp Power: 400 Watts Min Amp Power: 10 Watts Freq Resp +/-3dB (Hz): 34 Hz -- 20 kHz Freq Resp +3dB- 9dB (Hz): 25 Hz -- 20kHz Impedance (Ohms): 4 Ohms SPL in Room1w/1m(dB): 95 dB SPL Anechoic 1w/1m(dB): 91 dB X-Over 150 Hz & 2.7 kHz |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 15063 Registered: May-04 | . A nominal impedance of four Ohms isn't enough information to be useful. Your speakers claim a sensitivity figure of 91dB which is rather high and shouldn't require much of the amplifier. Have you had problems with the receiver shutting down or, are you only concerned the numbers don't match? . |
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Platinum Member Username: NuckPost Number: 15257 Registered: Dec-04 | Are the speakers from the same manufacturer, at least? Like kissin' cousins? |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 4118 Registered: Feb-07 | What's the speaker? I have that same receiver. I suspect it will be fine. |
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Gold Member Username: MixmastaspigTeam RD, Canada Post Number: 2088 Registered: Sep-05 | The speaker would be: http://www.axiomaudio.com/vp180.html @Jan Just concerned really that they do not match. My rears are the Axiom QS8's and they are 6ohm and I've had no issues at all, but 4ohm is a huge leap from 6. @Nuck Lol, kind of . The only speakers that would be out of the loop would be the towers (http://www.fluance.com/fluanes1higf.html) I didn't want to dump a ton and from what I heard in town in my budget (polk and energy) I was willing to risk it online. THey are great for starting but I want the Axiom towers as the http://www.axiomaudio.com/qs8.html are fantastic. Thanks! |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 15064 Registered: May-04 | . You've missed the point that a "nominal" impedance number is rather useless. Any multi-way speaker (more than one driver in the enclosure; 2 way, 3 way, etc.) will have peaks and dips in its impedance plot as you can see here; http://stereophile.com/floorloudspeakers/psb_image_t6_loudspeaker/index2.html At the very least you need to know the minimum impedance point of the plot. A nominal 4 Ohm system can be quite flat and not cause most amplifiers serious problems. A nomimal 6 Ohm speaker can have broad swings which will create issues for many amplifiers. So you're thought process that "4ohm is a huge leap from 6" is incorrect on face value, you simply do not have sufficient knowledge from those two numbers alone to make that assessment. Some manufacturers are more honest about how they spec their products and one manufacturer might be telling you the 4 Ohm spec is the lowest point you must consider while the other its telling you virtually nothing by spec'ing a 6 Ohm nomimal (or average) load which could dip to 3 Ohms at some point. Additional factors include the eletrical phase angle of the system and how that spec interacts with the actual impedance at any frequency, a low impedance accompanying a neutral phase angle isn't as serious as a low impedance coupled to a high phase angle. As I mentioned your speakers claim a fairly high electrical sensitivity which will (if the informaton is correct and it may not be since that spec is quite easy to fudge particularly with 4 Ohm speakers which use "1 watt" as their baseline) require less work from the amplifier to reach normal listening levels. If the amplifier is working less hard to reach a given volume, then the amplifier has more headroom to accomodate more difficult loads. No one single "nominal" spec tells you how your amplifier will react with any given speaker. Therefore, we cannot tell you go buy "this" or "that" and be any more assured of success than you would be if you did the work you're asking of us. Besides, what we suggest might not be what you like. You can, at this point, try several options. You can do nothing until you improve your amplifier first. You seem to have your head set towards buying a new speaker which you think is "fantastic" so that option is probably not going to happen though it is really the most logical route to take in system building. By improving what is in front of the speakers the speakers will naturally show the improvement made upstream. You can do your homework and figure out to the best of your ability how the impedance/phase/sensitivity specs will affect your amplifier's ability to drive a low impedance load. Many years ago amplifier/receiver manufacturers grew weary of covering the damage done to their product by poorly matched speakers. They started telling the consumer not to use certain nominal impedance loads with their amplifiers. Well, this means the amplifier guy can just make lousy amplifiers and blame it on the speaker guy or the amplifier guy can just put a sticker on their product telling the consumer not to be stupid. That doesn't tell you their amplifier won't drive certain speakers just that the amp guy doesn't care to be any more informative than the speaker guy who just says "6 Ohms". Next, you can call the speaker guy and ask for help since you want to buy their product and they really should be willing to give some assistance to a potential client. Or you can do some reading and figure the best you can what will do well with your amp. If you choose the latter, go to the "Speakers" section of the forum and read the threads on speaker impedance. Or you can do nothing to educate yourself and just go buy the stuff you want and then see what happens. If the Pioneer blows up, then you'll be right back to my first suggestion. But IMO your option of buying another amplifier just for the center channel is not that good. Now, maybe you were asking for a whole new receiver and you just didn't place this post in the right section of the forum. If so, then you need to make that correction here and we'll proceed from that point of additional information. In other words, a "receiver" is not called just an "amplifier". That's why there are two separate sections of the forum for the two different products. OK? . . |
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Platinum Member Username: NuckPost Number: 15262 Registered: Dec-04 | http://www.outlawaudio.com/products/2200.html |
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Gold Member Username: MixmastaspigTeam RD, Canada Post Number: 2089 Registered: Sep-05 | @Jan Thanks for the good information. I will read up on what my receiver can do and I don't think I ever mixed up amp or receiver in my questions...I do wish to keep my receiver and just power the center with an external amp. I also never said the center channel is "fantastic" I said my rear surrounds are fantastic. |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 4129 Registered: Feb-07 | "http://www.outlawaudio.com/products/2200.html" I have in fact used that very amp to drive a center channel before. |