Axiom Home Page Forums General Discussion Stereo M80TI Amplification

I'm just purchased a pair of M80ti's with the intention of using them both for music and movie playing and was trying to determine what size/type of amp I should buy. I see these speakers operate from 10 to 400 amp range but don't know what I need. My room is about 12 feet by 17 feet and I like to have the option to play music loudly from time to time. Any suggestions/guidlines ?

Thanks

HELLO,

I put in a request to Alan, a little while ago...To do a definitive piece on the M80's. Much has been written here about them, but I would still enjoy reading a complete post outlining the thinking behind the two tweeters and mid's, the best A/V receivers for them, and how they deliver more bass, etc.
With so many posts inquiring about them it seems like a good idea.

LT

I think Axiom has powered the M80s with up to 1,000 watts during testing. I imagine as much power as you can afford is the correct answer. If I were going that route and wanted loud I'd go with monoblocks.

My M80's and all the axiom set are powered by the 3805. In HT, they go to higher volumes than is comfortable to listen to.

In stereo go up REALLY loud.

I do not know what reciever you have, but if you have decent amplification, you may not need any additional amplification. Test them before buying anything additional.


Oh and BTW, the M80's sound Verrrrry sweet. You are in for a treat.

I have a Nad C370, in 4 ohms i believe it delivers around 180 wpc. It will go louder than I would ever want to listen. You dont need ALOT of power for the 80's. But i believe that you would be much happier if you got something that is capable of deliving the power that they crave to be driven with 10 watts would definetly not be enough to fully enjoy these speakers though.

Thanks for the reply. I'll be anxious to see what he say.

Thanks, I can't wait to get them. Actually I don't even have an amplifier so I want to get started on the right foot.

Hopefully, he will have time for a "refresher course post" for us. From what I understand he's a busy guy.

Is an amp really needed? Are you going to go with seperates or use that amp on your reciever? Most have found that an Denon 3803 or 3805 will drive the Axioms really well. Unless you have listening levels that are REALLY high, why the amp, that is unless you like the seperates sound. As you can tell, I am not a huge fan of amps.

When people answer this question they usually refer to how loud you intend to play your music. I found that with my M80's more power is better, even when not playing at high volume. I've posted this before so excuse the repeat info for the regulars.

I started with an Outlaw audio 1050, which is rated at 65W x 5. Most people say the 65W rating is very conservative and compares to most other manufacturers 80w ratings, I can't verify this. Anyway, the M80's sounded good, I thought, with this receiver. Then I borrowed a 2 channel 150w Threshold amp, wow huge difference, even at moderate volume. More punch, A LOT more bass. I ended up purchasing a used Aragon 4004 2 x 200W for $600, an older amp but very highly regarded. Sounds great, yes it will crank very loud, but I don't listen to it that loud very often, the wife has something to say about that. Lots of overhead, it can step up and deliver dynamic material, very tight and powerful bass, as well as detailed mids and high's.

I use a Rotel RB 1080 to run my M80s.It is rated @ 300 watts @ 4 ohm and it sure does make the 80s sing.Whether you deciede on a good reciever or quality seperates you will be quite happy with the choice of Axioms.

As you can tell I do like my seperates .

I'm just begining to re educate myself after a long time away from the a/v world so my terminology is off . I really would like to stay away from a dedicated amp just for the m80ti's. What I would like to do is find a nice a/v receiver that will drive the m80ti's enough to listen to my music and play movies. I'm begining to lean towards the Denon 3805 rightnow.


Thanks!!

I was looking at the 3805's stats and they have ratings for 8 ohms at 120w and 6 ohms at 160w. What would the wattage be for the 4 ohms m80ti's 240w?.

Thanks!!

What's not to like about amps should be the real question.

I would doubt it would double the watts into 4 ohm.I would guess it should put out around 180 @ 4.You could talk to Denon a find out for sure.

Simboticus-

That's an awesome Aragon amp, huh? Very nice choice. I think their older pieces are worth every penny. I've been running an Aragon setup but I've been keeping my eyes on Ebay and Audiogon for an Aragon amp when the time is right. Poor man's Krell, as they say.

-Kevin

In reply to:

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I was looking at the 3805's stats and they have ratings for 8 ohms at 120w and 6 ohms at 160w. What would the wattage be for the 4 ohms m80ti's 240w?.

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Yes, 240W. A 4 ohm speaker will draw double the power of an 8 ohm speaker.

Oops... Wid already answered. Sorry for the repeat.

My vote would be for the HK 7300. If AVR's were 4X4 off road trucks and you chained the 3805 and 7300 together, the 7300 would pull the axles out from under the 3805. (yes, I'm a redneck) One call has it for $1350 right now. Or, you could took take a leap of faith and go digital. The HK DPR 2005 is running about $900.

From what I have seen and read most amps will not double the power into 4 Ohms.In a perfect world they should but most do not.My Rotel is 200 @ 8 and 300 @ 4.This is most typical of the amps I have seen.About a 50% boost in power.Granted there are some that will double the power but I suspect they cost some serious $$$$$$$$$ to do it.

The ability of an amp to double its power output under twice the speaker load likely depends on the amplifiers internal source impedence (ie. the amps effective internal resistance from the power plug to the speaker output) or current limiting hardware they have put in place to protect internals from excesively high current.

Just a theory though. I have no data on reciever source impedences to support it.

sjanes,

It depends on how much current the amp can supply. Once the amp reaches it's maximum current output capability, it's done. This is the most important specification in an amp, from a power only perspective (not considering the audio stuff like THD, etc.). You can calculate the maximum true power output if you know what the amp's maximum output current capability is.

To find the current, we first start with what we know. We know the resistance of the speaker and the max power output of the amp. We do not know what the current is at the max power setting. We can easily calculate it, though. Ohm's Law. Works every time.

power = current * voltage (P=IE)

We can't calculate it using that formula since there are 2 unknown values, voltage and current.

Voltage = current * resistance (E=IR), so we can substitute this in place of the currrent value in the power formula above.

power = current * (current * resistance) (or P = I*I*R, which is P=I^2R)

Doing a little algebra, we get current = the square root of power/resistance. ( I=SQRT(P/R) )

current = SQRT( 120W / 8 ohms) or the square root of 15, which is 3.8 amps. So, into an 8 ohm speaker, the amp will put out 3.8 amps. Now we know the voltage at the output the max current was measured at.

voltage = current * resistance (E=IR)

So, the voltage at max power is 3.8 amps * 8 ohms, which is 30.98 volts.

We can now determine what the current requirements at max power will be with a 4 ohm load.

current = voltage / resistance (I=E/R)

The current requirement of a 4 ohm load on a 30.98 volt source at max power will be 30.98 volts / 4 ohms, or 7.46 amps.

If the amp has a maximum current capability of 7.2 amps, it will "run out of gas" at 223 amps with a 4 ohm load.

That's why a high current amp is important. Current puts the "oomph" behind the voltage.

I've heard Wid's setup and with the Rotel amps its just plain sweet. I purchased the Axioms after listening to his setup.

My recomendation is for you to go with a nice A/V reveiver like the denon 3805 or the 3803. Hook up your system and IF you feel something is lacking, then go with an amp. I too had the Outlaw 1050 and once I hooked up my system to a Denon 3803, there was a major sound differance. Not sure if that was because of amplification or due to the interial chips but it was noticable. If you feel that the denon is not driving your system well, you can always turn to the Outlaw Mono blocks to power your fronts. They are not much $$.

For those that question my need for an amp, I have to tell you that for me there is not that need right now. I know that there are some that feel more power the better but again for me I have not hit that area where I wonder how loud my system can go. I also wonder if this is an arms race for some, or a listening quality experience.

Thanks Spiroh,I appreciate the compliment.