Simple Question after reading the other thread about Mojo's lab calculations on the power handling of the ALFR seperate channels.....

If I remove the binding post connector's on my M60ti dual binding posts how do I calculate the power handling?

The specs are rated at 250 watts RMS / 1000 watts dynamic, well at least the v4's are, maybe the m60ti is different, i couldn't really find anything solid that lists the old specs.

Does the spec change if the woofers are seperated from the mid and tweeter? I'm thinking yes as we all know the woofers take the majority of power to drive the low frequency.


This is more of a thought experiment really as I don't have amps to try anythinh with. In fact i've got 3 pairs of speakers sitting here and not one amplifier or intergrated or reciever to play anything right now. My m2's look really sweet. I like the black oak. It's better than i expected it to be.

The short version: I'd not worry about it. Bi-wiring, as you may already know, the power draw is the same. Bi-amping works as long as both amps have the same gain. Both sides (woofer, mid/tweeter) will consume only the current (power) it needs.

Longer version:
An amps power rating is really a spec of the the amount of current it can supply to all the speakers connected to it ... i.e. the power an amp can supply to two speakers is a lot more than if it was driving 10. So, already the amount of power available to each speaker varies with the number of speakers and time. A speaker is designed to use voltage as its input. It will draw what ever current it needs to do its thing (at that voltage and frequency). Power = voltage * current. The other side of the coin limiting an amp is it's voltage rails. An amp with high voltage rails might drive an 8 ohm speaker to it's full rating but not a 4 ohm speaker. The reverse is also true ... the same power amp with low rails might drive a 4 ohm speaker to it's full rating but not an 8 ohm. Both will result in clipping. The voltage rails are a hard clip. The power limit clip (current) comes into play once you start continuously asking for it. Extreme clipping is, IMO, what kills most speakers.


With 250 watts continuous and 4x dynamic I'd be pretty sure you're safe on the M60ti either way you connect them.
Hope that was the answer you were looking for.

Thanks Rich. That is a good answer to my post. I should've added more to my post I now realize.....

If I was to have whatever number of seperate amplifiers I wanted to put into each channel. L and R woofers and L and R mid/tweet on an m60ti, what amplifier power could the woofers handle versus the tweeters and midrange? (Bi-amping scenario i guess.) (As a footnote i personally dont think bi wiring does much of anything but I think that bi amping does as I think the extra power added to each channel or pair of channels would improve overall headroom if you used the right power amounts and would also improve channel seperation i believe.)

Put another way, the 250 watt RMS spec is for the whole system, woofers midrange and tweeters. If I seperate them does the power handling spec change? The tweeters and midrange will draw what current they need and the woofers will draw what they need. I guess im trying to ask does the same thinking apply that mojo proposed to the ALFR ratings he spewed out. (the trouble maker that he is really.... )

Requoted here from the other thread:
"The triple woofers are 800W, each mid is 75W for a total of 300W and each tweeter is 25W for a total of 100W. Hence 1200W."

Not that im going to do this but I could give each channel its own amplifier to improve headroom and thus overall dynamics. (Keepng in mind Andrews recent video about head room). If thats not the case then why bother with the dual binding posts on the speakers?

I hope im explaining myself better.....

The triple woofers spec is for the HP drivers. The regular woofers are probably 119.63478W each.

250W is for the whole thing.

Axiom put the dual binding posts on there because customers asked to bi-wire and bi-amp. They didn't want to lose sales. It also makes them look more "upscale" for snobby audiophiles.

Don't waste your time.

Good enough for me. So basically put a reasonably powered amp that matches the RMS or close and call it good.

Indeed.

I just noticed the M60s can now be equipped with HP drivers. When did that happen?

The power spec stays the same with HP drivers. So the power is limited by the cross-over?

The HP option on m60's has been there for a quite awhile. As long as i've been surfing around here, so about 2 years. Yeah i noticed that too, the spec doesn't change for HP, doesn't change for m80 either going from non hp to hp. It must be a different spec if they are designed to handle more power, the power spec should change.

Using our agreed logic above (get an amp near the RMS max of what your speakers are rated for) an ADA-1250 would do the trick for me with 225 watts RMS at 8 ohms my m60ti with the upgrade path to either m100 or LFR. Or do I spring for an ada-1500 with my giant room and run that with my m60ti? Should be fine i think....it will supply 325 rms into 8 ohms.

Mojo has been quite on how he came up with that. My recommendation would be to drive each with 2 channels of the same amp. In that case everything works and the issue is moot. Trying to optimize amps to each is kind of impractical and as you say a mental exercise.

if I were to attempt it I'd measure the current that's being drawn by each speaker input at several frequencies and calculate it from there. But it takes some equipment you probably don't have. A function generator and a decent multimeter. You can do it manually or if both of these can be controlled by computer automated. Then guesstimate a nominal impedance from each input graph

I'd pass this by Mojo to see if he thinks this cheat might work ... but you might get away with measuring the DC resistance of each input and use that to get a rough estimate of how the power in would be divided. Not the best way but it might give a good enough result ... by the way the power split is inversely proportional to resistance.

Kodiak,
My guess is if two M60s can fill your room that an ADA1250 will be plenty. Can't imaging anyone getting close to it's max power in ... unless you like to listen from 20' to 30' away or like Mojo wear muffs to sit closer

I've never explored this but here's my thinking on bi-wiring ...
if your speaker wire size is marginal the current draw of the woofer may effect the waveform distorting the higher frequencies. By bi-wiring you can eliminate that distortion.

It is one reason I like to see a wire resistance less than a hundredth of the nominal speaker impedance.

Bi-wiring reduces inter-modulation distortion (IMD). Whether or not you can hear the difference depends on the magnitude which in turn depends on the current, cable and speaker characteristics. I've tried it, couldn't hear the difference at any level, but it doesn't mean it wasn't there or that others can't hear it on their systems.

mojo my guess is if you want to hear it you might have to exaggerate the effect … try listening for it using a wire run with a high resistance… maybe a 100’ of 24ga

Thanks Rich. Im wanting to slowly build up my great room and at some point I will either have m100, LFRs or maybe even m5hp to start with. (Which is why i suggested the ada-1500, will the ada-1500 wreck my m60ti as the RMS is higher than what the m60ti is spec'd for?) I sit back 12 feet and can go as far back as 20 feet with listening position. So my plan is to buy components that will power those options in the future but use them right now with my m60ti. The m60ti will end up doing duty downstairs is the future home theatre. It's a large space. All just plans and thoughts right now. I guess an ada-1250 could travel with the m60ti into the theatre in the future too....

I'm focussed more on getting my bedroom m3 setup dialed in (still on the hunt for a one box fully featured integrated with respctable power and capacitance) and my office m2 desktop setup with headphone station. (I'm thinking the JDS Atom+ and Atom Dac+ that you recommended a while back. Using it as preamp and dac to run my m2s...I will need to buy some type of power amplifier for those too...)

As for bi-wiring comments there, maybe yes things are possibly changed and can be measured but sometime i think alot of the changes that can be measured are unlikely to be able to be heard by humans. Can't hurt to try and experiment with it all though.

There is no harm in going with a 1500 for the M60. Recognize though that the 1500 can, if you turn up the receiver gain enough, totally incinerate your M60. That is not the case with the M5. I don't know about the M60HPv4. The limitation there may be the crossover board.

Before you do anything, I urge you to write to Andrew. Ask him what the rated average and peak power is for M60HPv4. If the rated is at least 400W, I strongly urge you to set aside any dreams of owning ALFRs and going to ADA-1500-2 and M60HPv4.

If you decide you must keep the ALFR option open, ask Andrew what your ADA roadmap possibilities are so that you don't strand your investment.

Thanks Mojo, all good advice. I think I will reach out to Andrew, good idea. I have a feeling the HP versions spec out a bit higher, just a common sense feeling but then again im routinely wrong just when I think I understand somethinga little bit.

As for M60v4hp, interesting purposal. But why not go to an m100 if i'm going to upgrade?

Also, can you expound on this...." I strongly urge you to set aside any dreams of owning ALFRs and going to ADA-1500-2 and M60HPv4." I don't think I understand, why would a squash my dreams of having ALFRs?! ( Keep the dream alive brother man!)

Don't worry about the ADA1500. I kind of doubt you'd turn it up beyond what an ADA1250 or even a ADA1000 could produce. It would be LOUD.
Mojo, Do the ADA's protect against clipping in anyway?

Assuming that answer is no ...
You'd probably pop the M60 on a ADA1250 before an ADA1500 because the 1250 (or 1000) would start clipping sooner ...

We can't assume the HP drivers in the M60 will result in higher power/SPL. The crossover may not be designed for it. If you want higher power and SPL, you may have to move up. But, I'd bet, within its power and frequency spec, the M60HP is more linear than the M80.

As for the M100, the M60 is more linear. I've said it many times before and I'll say it again. I like the M5 bookshelf better than the M100. The M100 goes louder, forms larger images and soundstage, sounds more real but it also gets in the way of itself when it comes to imaging. The M5 is invisible and I didn't even have to try. So is the M2 and M3. But the M100 is not - not in any of my rooms. Sure, I may be encountering "position error" but I can only spend so many hundreds of hours trying to find the right position! So now that I know the M60 comes in HP, I presume it sounds as good as the M5 and it comes within its own "stand". It goes lower too.

I suppose it depends what's important to you. Acoustic invisibility, or lack of audible resonances, is paramount to me.

As for the ALFRs, unless you plan on throwing dance parties, you don't need them. The passive Axioms are that good.

The ADAs self-protect by transiently muting when their temp or power specs are exceeded. It's pretty cool. Not offensive at all.

The 1250 or 1500 would fry the M60ti. The ADAs protect themselves; not the load.

Ok, that makes more sense now Mojo. Really it does. And I DO remember you saying it over and over again that the m60 is more linear than the m100. Great comparison of m60v4hp to m5 in terms of power spec/handling and that it comes with a "stand" and plays lower. All very good points. Thanks. Really good food for thought. So I guess the question remains, does the m60v4hp disappear as well as the m5hp given the differences but closer to it than all the other towers. That could be the ticket for my space.....I really enjoy it when the speakers just vanish into space, its so cool, albeit in a limited way with the m60ti.....plus a couple of subs if needed, it's rather large and voluminous in here. ....... Theres definately room to add some more large waves in here and not have them be a problem I think. The m3 does it easily and the disappearing act is wider and easier to remain in while moving around. Havent tried m2 yet. Theyre just here staring at me.

Also, that is strong endorsement of the passive speakers versus the ALFR, wow.

The M60 appears more linear to me than the M5 so that's a good indication it ought to disappear as well. Then again, the published curves are for the standard M60. I have no idea what the M60HP curves look like. All it takes is some cabinet vibration of the right amplitude and bandwidth and BLAM! the speakers become visible.

With the M3 and M2 (and M5), try dropping them 6" below ear level. I am really curious to know what difference it might make for you.

So the oak is sweet, eh?

Like i said, my m60ti do disappear and it's really cool. It's a must have for me.


I'll ttry that but i have no yammie for about another week or so. Still waiting on my za-1000 to arrive at work, yammie is filling in there temporarily.

And yes, the black oak is much nicer than i than i anticiapted. It's really stout looking and will jive well with my desk and office zone with all the black screens and computer stuff etc.

When the new Axiom subs are introduced, I might trade in my 800v4 black vinyl oak for real black oak. It's a big decision for me because Ian built that sub, wrote the 'nad tickler/gut punch DSP code for it and then tested in the chamber. He built custom artwork for the amp panel with the 'nad tickler/gut punch lettering. He then dragged Andrew onto the factory floor for driver signing. It's real special. Every time I turn it on, I give it a little pat and a wink.

I'm telling you, you don't need ALFRs but you do need an 800.

Oh man.....you cant let that go....its one of a kind!!!

But if you do, rest assured the black oak is really nice. Classic is another way to describe it. The pair i have are b stock but ive looked all over them from every angle and i cant see anything wrong with them, theyre basically perfect.

Whats the skinny on the new subs? Newer and improved DSP code? Even beefier drivers and amps? I've always fancied 2 subs playing in stereo as something id like to try. Maybe the new subs will come out in the future when im ready to throw down for my great room setup.

Nad tickler....nice. coochy koo.

No need to be without an amp. Here's your chance to try tubes. From Amazon. With the standard Power supply, you'll get 80W/channel.

SUCA AUDIO HiFi Bluetooth 5.0 Amplifier, 6K4 Vacuum Tube Power Amplifier, 2 Channel 160W+160W Home Stereo Receiver Digital Audio Amp for Home Passive Speaker, Bookshelf - with Power Supply https://a.co/d/bgQw5BJ

The new subs will come with an app.

Oh sweet. Thats awesome, variable phase adjust etc like the app I saw with the svs subs. That will be really cool.


I'm leery of trying the really cheap stuff. I was looking at maybe Reisong a10 as recommended by 2x6. Now might be the right time.

The cheaper one may be better. Try both. Punt them back if they suck.

I think Rich had the best answer a few pages back in the speaker only pulls the amount of current needed at any point in time. Wrapping your head around the RMS max is a bit of a fools game in speakers are never played at RMS max. buy that i am saying that in listening to music on your speakers, I don't know of anyone who would want to be listening to a constant tone that will generate the RMS max condition. Music is a constant changing sound output that some parts that are load may be using far less power than other parts that are seemingly quieter but more complex requiring more power to create.

I recently moved from a set of passive LFR being run by an ADA1000 that at no point did i experience any feeling that the output was being compressed or distorted by running out of power. The new Active LFR are getting powered by two 5 channel ADA1500 and I can not personally that I am hearing the night and day improvement from regular listening volumes. The Active can get louder than my old ones. I have set my Pre to limit the volume to -15db. Working on the concept that sound volume doubles every 10db, I know full well that I could if I wanted to get the speakers to be 8 times louder than what I have it limited to and maybe it is at those levels that the 1500 would shine well about the 1000 that I had, and my experience is contained in just not listening to music loud enough.

If you're having a dance party you just need loud and reasonable fidelity ... no one is going to care about imaging, stage, or other such non-sense ... ahhhh, IMHO

Nope no dance parties. Just me myself and I when tbe house is empty and crank it up and enjoy. I do enjoy to listen to it loud once in a while but it breaks up when it gets loud right now. The amp runs out of juice. It gets messy.

When the time comes I should just get both, passive lfr and standard passives and compare.

In the meantime sounds like an ADA 1000 will do it.

I just realized I’ll have a chance to try all my axioms with the za-1000, when it finally arrives. It’s coming to my house. It’s basically an Ada-1000 as an integrated amp. .

Congrats on the actives ... I have the same configuration not because I thought I'd need 1500s but because Axiom had a deal on that package I could not pass up. There is no way I'd ever use even 1/2 that power ... even for a party unless perhaps if I was to setup outside for listeners 25-100' down the road ....

Of course there is the self fulfilling use case ... if you enjoyed them at 1/2 volume and lost your hearing ... you might need to go a little louder the next time

I'll bet you at least a beer that the ADA1000 will do it ....

I think you're absolutley right Rich. I'll still give you a beer for participation.

An ADA-1500-5 is being sold second hand.

$1800. It’s still got 3 years warranty.

Stupid captain obvious question here….

If I get a 5 channel but only need / want 2 will the amplifier still deliver 2 channel specs ? I think the answer is yes.
Any negatives here to having 5 channels?

Could be good for future upgrades, like going to a 5.1 or 5.2.

Thoughts gentlemen?

Here’s the ad.

https://www.canuckaudiomart.com/details/649867540-axiom-ada-1500-5/

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Yes it will give you the 2 Chan specs if your not using the other 3

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The 3 other amps will still be on (when not in stand-by) creating ~40 watts more heat than the 2 Chan version

I think that's a ridiculously good price for the amp.
Agree with rrlev on the power consumption though.