Axiom Home Page Forums General Discussion Advice from Axiom Owners General Help, Suggestions, Advice, Discussion

Hi all,

I've been reading posts around the web lately, trying to gather information on possibilities for my home system. It has sort of morphed into an unorthodox set up so am trying to find some creative solutions.

Back in 2006 I ventured into the Axiom world with a nice treat for myself. 4 M80v2s, 1 VP-150, and an EP-350. They are running off a Denon AVR-4306 right now and I have been extremely happy with the purchase since. In the back of my mind I have always been curious about the side effects of running 4 ohm speakers on a receiver specified for 8 ohms, but have seen no issues yet, and I have cranked it quite a few times over the years.

This is where it gets more interesting. I recently came across someone who inherited an Axiom set and just wanted to get rid of it quite cheaply. So I now additionally own more Axiom equipment: 2 M80Tis, 4 QS-8s, and another VP-150. The speakers are in fantastic condition but the grills are a little banged up but not enough to pass on them.

So, this is where I am trying to gather information. One problem I have is placement of all these speakers. I live in a NYC apartment, so space is limited but it's not a shoebox. I think over time I will figure out where to mount and place these speakers. But the larger issue I am trying to sort out is how to power these speakers. One Denon AVR-4306 obviously won't cut it so am now considering dedicated amplifiers, but have never been down that road before. Having these speakers that can handle up to 400 watts each, what kind of powering options should I be considering? I notice that Axiom offers an amplifier. Are these good, other brands to consider? Even the Denon claims 130 watts x 7 into 8 ohms, but what am I really supplying to my speakers now by comparision. Boiled down, what power options should I be thinking about, considering, weighing, reading about?

Any suggestions, thoughts, ideas, and general discussion points are warmly welcomed. Thanks in advance even if you have read this far. :-)

Summary:
M80 v2 4x
M80Ti 2x
QS-8 4x
VP-150 2x

Frank

one option for amps that will give you the same quality you're enjoying now but at a much more interesting price (than audiophile amps) might be pro-amps from Crown Audio or QSC or others.

to get an idea about that, pls see "My HT room" in my sig.

total power in my system is about 8000 Watts (same as my winter baseboard heaters' total).
it means it just loafs along and is ready to reproduce the highest instantaneous peaks without a hint of distortion.

pro-amps usually don't need flat fr.resp. below about 32 Hz, so some of them filter it off. if you need an amp to reproduce those, check closely on the specs before you buy.

in closing, my qsc amps carry a 6 year warranty. :-)

hope this helps.

J.B. - Thanks for the response.

Quick first question. You have the QSC PLX3602 running your 2 M80s, correct. The specification for that amp states 1250W per channel @ 4 ohms if I am reading that correctly. And the M80s max power is 400W. What am I missing? Shouldn't this blow out your speakers?

at first, i wanted to buy a third QSC-GX5, but saw the PLX-3602 at half price, so i bought it.

too much power is "spare power"; mainly for peaks.
as long as you don't hear distortion from the speakers, then all's right.

a better and much faster way to blow out M80's is by using a 50 Watt amp and turning the vol. control to the max.

most of the time, i use less than 10 Watts total,
but i've also used around 2000 Watts a few times when playing high peaks in a very loud passage.
it never sounds like 2000 Watts, because it lasts for such a short moment in time that you don't notice it. this ability for fast peaks is what makes for a very realistic reproduction.
i always listen to music and most movies at "live level"; this demands another type of audio system compared to someone who only wants "background music".

spare power is like a car: you might only need 50 hp to cruise on the highway, but what about passing? this is when you need spare power.


hope it helps. others should be able to give you a better answer.

The analogy sort of makes sense to me but when I compare 400 watt max on the M80 and 1250 watt on the QSC PLX3602, some part of my brain says, "that's not good". :-)

I'll keep reading. I'd like to understand why/how that much spare power is okay.

Thanks again.

Another quick question about using pro-amplifiers. How do you handle the inputs to the amplifier? I see most of them have XLR inputs.

i bought cables with RCA on one end and XLR at the other end.

Any experience with ground loop issues? I notice posts complaining about humming and buzzing noises.

the only noise i hear, with 3 amp fans running, is when everything is quiet then i hear them quite weakly, but the instant there's a sound through the speakers, the noise disappears.

i consider myself lucky because since the 70s when i got an audio system, i never had any hum problem (and no buzzes).

The sad side to Wattage in relation to speakers is that it's not all equal. Ohms law says that W = V * A. So on many of the lower end systems they can juice up the Voltage and get away with close to no Amps to give a very nice Watt's number. Will the speakers work well? No.

I have an Anthem MCA5 that tips the scales at 57lbs and does a reasonable job at powering my speakers. (150w x 5 channels) and all it does it amplify. Your Denon tips the scales at 40lbs and says it can do 130w x 7 channels and has all the other DAC's and components inside. Something doesn't balance out here?

Your question however is what does it need to drive these speakers well? I'd say about 45w of true clean power each channel. The challenge however is to figure out who is selling you smoke, and who is actually delivering you the real thing.

I was shown that numbers don't matter when I first got into audio and went to the big audio shop in Toronto, and they had a 30w Cambridge Audio receiver setup beside a 200w Sony. The Cambridge sounded way better and actually felt louder than the Sony. It also weighed 3 times as much.

You really need to look into the actual spec's of anything that you buy. What is the size of the main capacitor? How much headroom does it have? What is the current pull on the unit?

Now your receiver does at least have Pre-Out's so you can hook up an external amp to the unit. If I were you, I'd skip trying to buy new as your just paying upfront for the depreciation for the next person who owns it. I'd look as to what is availible on the used market at http://www.usaudiomart.com/ and save yourself some coin in the process.