Axiom Home Page Forums General Discussion Advice from Axiom Owners Selecting the right amp for the LFR1100

I guess this is as much a question out to Craig who seems to know quite a bit about testing and has listened to the potential of Axiom's LFR1100 v4 speakers.

I will give Deb a call in the week to get a price for the ADA1000 amp, but just going off the list CAD there are quite a few options for the $1500+tax list price of this unit.

I have not tried this amp so I have no real basis to examine how they sound. I have used an Anthem MCA5 and once you get past the ground loop humm the 250w of power does have what it takes to make the LFR's sound good. My lesser Amp/One at estimated 1/2 that power doesn't seem to have the same dynamics.

But I have read on these hallow pages of owners of the LFR's running on Crown XLS amps and did not hear any negative word. From a price perspective two Crown XLS1002 can deliver 350w for around $1000, or even an XLi800 for 300w for $800.

I am gathering that it would make far more sense for me to simply look at two matched stereo amps than try and find a 4 channel option. But even an Emotiva XPA5 can give me the 5x300w at 4ohms for about $1100.

What are others using, and do you feel that you are getting the sound output that you fancy? I have about $1200 to spend hopefully taxes in.. but can scrimp and save a bit more if pushed.

Ask Axiom for the frequency and phase response curves of the LFR serial number you purchased for the SPL range you'll be listening to. Then send these to Emotiva and ask them to evaluate if their XPA5 can remain stable across the SPL and frequency ranges.

Or just skip that and buy the ADA from Axiom. I trust Andrew did his homework.

Please excuse my ignorance.. but what does SPL mean?

Sound Pressure Level.

In the above, I should have said impedance response curve instead of frequency response. You want to find out if the XPA5 can remain stable across that impedance response for all sound pressures of interest.

I gave a phone call out to Axiom and spoke with Deb.

I inquired about the ADA1000 and her take on it was that driving a pair of the large LFR1100 with that amp was not recommended. Maybe for a small pair of Bookshelf like the M3 or M22, but not for the floor standards.

The amp just wont handle the power pull for the large speakers and I really need to look at the ADA1250 at pretty much double the cost. OUCH!

Well, I left it that we'd see what Ian can do or say about this purchase, but at this point it looks like someone else's amp is going into my home.

I am stunned! Is it because the 1100 is highly inductive at low frequencies?

I am double-stunned given the 1100 overview page specifies the ADA-1000 as a good match for the 1100.

Silly people lurking. C'mon Mark. Quit fooling around.

I got the quote back from Deb and it's basically selling at Factory Outlet prices.

She gave the price for the ADA1250 that is 312w@4ohms;. The ADA1000 is 250w@4ohms;

By comparison, I can buy a Crown XLS1002 and get 350w@4ohms; so i will gather it's about in line with the mid level Axiom amp except it's a switching power supply over the Axiom linear toroidal unit. Now according to the video from Andrew, the linear powersupply allows them to upgrade the unit to as many amp boards with the same power design. The Crown does not do this but really do I care. I just want 4 channels so I'd buy two units and on the shelf they go driving the speakers.

So we are back to the unanswerable question of which of those two amps would sound better? Craig?? and opinion??

Matt - I am still officially listed as a dealer for Crown products, and am quite familiar with the XLS line.

I am currently still running the ADA-1000 into the LFR's, even though I added an ADA-1500-4 into the system (planning on using the 1000 for the upstairs theater). The reason I have not swapped the 1500 into the system yet is twofold:

1. It's been a zoo around here with kids home from college, 2016 planning for my financial services company .. etc ...

2. The ADA-1000 is just plain so good I have not been tempted to move it out and the 1500 in.

It's a premium product with a commensurate feel to it, and is hand built. The Crown stuff is basically Behringer quality, made in China gear, and feels like it.

Crown's upper end gear like Macro Tech gets that high end feel, but the lower price stuff doesn't.

The lower price stuff will have fan noise, and is prone to clipping harshly. The ADA-1000 will never make a bad noise, even when pushed.

The ADA-1000 will still be going strong in 10 years. The Crown will likely be your third or 4th amp in ten years.

For overall feel, it is somewhat like purchasing close to Bryston quality for a fraction of the cost.

That was my personal purchase decision - your decision and thoughts may differ from mine.

Craig. I get your thoughts. The Crown amps are made to a budget and as for how well they will last, only time can tell.

I would believe that the ADA1000 with 4 channels costing about the same as the larger Crown XLS1502, I will give up loudness potential of the crown for better life and maybe a cleaner sound matching as Andrew has made both the speakers, DSP and Amp so they better sound good together.

The word from Deb was that the ADA1000 cannot drive the LFR1100s to their full potential. I don't know what this is based on. I right now don't have a Pre-Amp as I sold the one that I bought last year as i was having more difficulty getting it to work, and to be honest, if you ignored the humm at no output, the sound to me didn't come across any better than the Pioneer AV receiver. Now it did have far better crossover support and with some percerviance it may have been better that I could get. But my thought was that I may be far better off waiting and saving for 2-3 years and buy something more newer with better support when Atmos and DTSX gets more firmly finalized in the market. Home by then that the CAD will bounce back we can afford something nice.

I don't know what having more volume will do for me. I listen in a 2100cu' room and to be honest don't get above -20db that often, and have never gone over -10fb on the receiver ever. I do have the two EP500's so I don't know if there is any way with my Pioneer to set a 40hz cross over.

So as I would want to get going on this... Do you think that the ADA1250 at over double the cost will give me anything substantially more than the ADA1000.

Your help is very much appreciated.

Matt especially if you don't go loud the extra wattage would help your LFE from the speaker. It wouldn't go to the loudness it would be directed to the 40hz crossover.

brendo. i fail to understand what you are saying.

I understand how an amp works and understand that the wattage goes into driving the magnets on the speaker coils that produce sound. Different sounds require different amounts of power.

A louder sound needs more wattage as it needs to displace the speaker cone more.

A complex sound also can need more wattage as every time you change the direction of travel of the speaker cone, you need to use that power to overcome velocity and momentum.

I also get that the octive of the sound also plays a roll in wattage as you are moving air to generate that sound wave.


I guess what you need to figure out is what would be the maximum power required by this speaker to play any and all my music at 90db at 3m? Then from that I could then figure out what is the maximum volume you could get from these LFR's with this amp.

What Deb has indicated is that to play everything and get to maximum potential volume (total cone travel), that the ADA1000 doesn't have enough power inside of it to achieve that but the extra 65 watts the ADA1250 has (or is it more current inside the amp too) would have the ability to achieve this.

Matt ... The difference between the two amps is this: The 1250 can deliver one more dB in SPL than can the 1000.

Based on the 93 dB in room Sensitivity rating of the LFR-1100's, here is a comparison in max output from a single LFR-1100:

LFR-1100 plus ADA-1000-4: 117 dB
LFR-1100 plus ADA-1250-4: 118 dB
LFR-1100 plus ADA-1500-4: 118.75 dB

If you didn't have the EP500's, we would be having a conversation about woofer control and greater current capability of the ADA-1250/1500, but with your system, the ADA-1000-4 and a pair of LFR-1100's will actually hit peaks of 120 dB at 1 meter.

That's front row rock concert loud. That's "I am going to need a hearing aid" loud.

The aspect of the ADA-1000 that I really like is it has this NAD like ability to never distort. Dynamic headroom is outstanding.

If money was no object, I would never hesitate to pull the trigger on an ADA-1500. But for the money, the ADA-1000 is an incredible value.

It's one of those products that has great specs while playing far above its specs and its price.

Mines been flawless, never once gave me issues.
Trigger is instantaneous.
I like having it during movie playback, no clipping when not using subs.

Hey Matt, if it would help, would you like to make the drive over to Vaughan to listen to my LFRs driven by the ADA1500? Or would that just make things worse?

I'm still having trouble rubbing two coins together to get the cash outlay for an ADA1000.

but if you are inviting me over as you just won a Powerball draw and happen to have any extra 3k laying around fun money that you'd like to give me ;-)

I will keep your offer in mind for march or april when the weather is not so frigid and driving up to the great white north of Vaughn is a bit easier for me. I'd love to hear someone else's LFR setup so I can gage if I have screwed up my setup or am on track.

Sorry Matt, I don't play lotteries nor do I have stacks of extra cash cluttering up my home! Happy to set up a listening session in spring though!

So. I can't listen to my LFRs anymore. I sold my Anthem amp so I am now missing that important piece that makes sound come out of them.

I guess I will have to see if I can get a workable number for the ADA1000 from Deb. Otherwise I guess I am stuck with Crown or something else inside my $1400 budget.

I have been thinking and if I can't get the ADA1000, looking at the impedance vs frequency graph, there are two lines. I am thinking that the second higher line is the rear speakers as they don't have the larger 6.5" drivers and are two way vs three way crossovers.

If that is the case, then the rear speakers will be easily driven by a much smaller or less powerful amp than what is required to drive the fronts. I already have some smaller amps that really don't have the guts to drive the fronts, but might be perfect to drive the rear set. So a $1400 budget for a 2 channel amp is far more easy that trying to spend that amount for 4 channels worth of equal power (if that power is really not needed).

This thread can now be closed.

I took the plunge and bought the ADA1000-4 at a bit more than was budgeted but still in my reach. Now I have to wait the 3-4 weeks for it to get made and shipped out to me. I know it will sound great and should have zero issues with the rest of my equipment. No humm's and enough power to bring a smile to my face.

Now I have asked and am waiting on the answer:

The ADA line of amps that Axiom sell are modular in the sense that they can be upgraded to add more channels at a later date as these are just amp boards that connect to the common linear power supply. On the spec sheet, they talk about "Max Output per Channel XX Channels Driven".

Now does that mean when the extra boards are installed, that is the maximum power that can be driven output regardless of the load on each channel?

For instance, if I have the ADA1000-5 and use it to drive 4 surround channels and a center, the center would have far more load requirement than the surrounds. Now would the center channel be able to deliver the Max 250w@4ohms as the surround channels will never require anywhere close to that amount of power.. or just because there are 5 amp modules inside the ADA1000, your maximum will be 200w@4ohms.

Guess this is an Andrew question as he designed this amp and will likely know.

As an additional question, what happens with the amp and it's output power when you have different resistance speakers hooked up. Like with my example, if you have 4 QS8 speakers @8ohms and a VP180 speaker @4ohms. What power would you get for the VP180? as it says all 4 of the QS8s would get max 125w

Yes, I bought the 1500-4 amp and forgot about the center channel. I also have the LFRs and the center channel in the DSP box, but I tried hooking the center channel up with an Outlaw mono through the DSP with the Axiom amp and I get a hiss in the system. So I bypass the DSP with the center and no hiss.

I guess the different gains are a no no with that. I hate to send the amp back for one channel but I might have to.

The problem is the Axiom DSP and I hate to say it... but it's badly designed. It can really only work with an Axiom AMP because of the way they implemented the floating ground on the unit. Your Outlaw mono probably has a more standard Direct Grounded Output design that is used in most of the major amp units on the market. I wonder if anyone has tried to hook up the Axiom DSP to a Bryson amp to see if it works. I don't know if it's a design thing with A/B type amps, but not with class D or Hybrid designs out there. It rather sucks.

I'm interested in this thread. I currently have M22 fronts, VP150 center and QS8 rears. I run a Denon AVR-991 and when in movie mode I have a Dayton HPSA-1000r amp running a big SVS tube sub. Been thinking of cranking up the power to the components and let the dogs eat. Been looking at hundreds of different posts in different forums on 5 channel amps and stacks of single channel amps. Just thought I'd check in here and see what people are using.