Axiom Home Page Forums General Discussion Stereo Passive LFR1100's and what to expect

I'm having trouble understanding what the DSP1 I purchased recently is doing. My expectation was that the sound would be almost holographic but with definition in the imaging width spread. I don't hear that. I get the depth and width within the bounds of the speakers but no extension beyond. I've heard stereo sound when the speakers are out of phase and that gives that holographic effect (with no bass)

I note too, that the balance control on my preamp does not completely pan left and right and there seems to be bleed from each channel.

I have my LFR1100's 15 inches from the back wall (actually 3 large 7 feet high glass windows) and about 6 feet apart and a listening distance of 10 feet toed in about 10 degrees. I have the boundary switch to off as the sparse information page on the speakers suggests for the speaker positioning I have.

Also for interest's sake I swapped the rear and front amps over and noticed the rear amp's sound has no mid or low Bass when through the front drivers. I guess by design.
Can someone explain the (Power?) button on the Axion DSR1 does as it does not shut the unit off when it is assumed to off (button out). It will go off if switching off at the rear.

I realise the design used phase changes for fool the ear but as far as I have it, I'm a little disappointed.

What advice does anyone have?
Axiom seems impossible to contact these days for information and their product documentation stinks.

I can't speak for everyone else but mine really opened up using the 3/5 ratio back wall to side wall. Both measurements are to front side middle of the tweeter. I have mine toed in where they are firing just to the left and right of the MLP not directly at it. Every room is going to be different but this is the general idea. Mine are pretty much invisible and the soundstage and imaging is incredible. Certain songs you'd think all of the surround channels were playing. The dsp separates the front and the back speakers in the passive 1100s so the sound doesn't cancel each other out or cause weird wave effects. I'm sure others on here can be much more specific but that's the general idea. I would continue adjusting the speakers or maybe even your MLP if you can. 6 feet apart at 10 feet listening distance feels like the speakers might need to be a littler farther apart if you have room and not get too close to the side walls.

Thanks. I'll experiment with placements then.

I’ve only played with actiives but suspect that the passives are similar. In the HT, which is currently a very lively room (no carpet/treatment), I find the setup to be extremely sensitive to placement.

About a year ago I did an at-home comparison of the LFR660s* and the M80s and came to the conclusion that there wasn't enough of a performance boost to the LFRs to warrant the added expense and complexity. I think it may have been a set-up/placement issue and I wish I had spent more time playing around with placement.

(*I just noticed they no longer show the LFR660, anyone know what was behind that?)

I wonder why Axiom doesn't include a calibration chip and microphone with the DSP; similar to Audyssey or YPAO. Then they could tell you that you hit the proper band or you have to tweak more.

So I did some measurements to understand what the DSP does. Place an SPL meter 6 inches at front and rear at mid midrange drivers. Used inter station white noise as a signal source and set the front side SPL to 0dB.
Measuring the rear drivers I got
setting
2 Near -2dB
1 Near 0dB
Off +2dB
1 Far +3dB approx
2 Far +5dB
The front and rear amps are not matched.
Front is a Forte Model 3 202 WPC 8 ohms 275 at 4 ohms
Rear is a Bryston 3B pro 100 WPC 8 ohms 200 at 4 ohms
Note the Bryston seems to have better sensitivity and appears to be louder for the same input.

I can't tell if there is any change made in the Bass responses as I would expect for room boundary bass compensation.
Perhaps the old speaker placement scenario is expected to be used to tame rear wall bass extenuation.
I wish Axiom would explain how the DSP works but the company seems too busy absorbing Bryston to care.

A few things:

1. The LFR-1100 has been in production for over 8 years. The purchase of Bryston has nothing to do with an explanation of the DSP.

2. Your amps need to have the identical gain in order to get the proper sound quality and holographic image.

3. The rear of the speakers have no bass, and the DSP recognizes this. Swapping to the front the DSP as intended to the rear will result in no bass.

4. What are your room dimensions?

Point 1. Then over 8 years you would expect to receive a better written user manual. I have the impression that Axiom is short staffed and have little time to spare in dealing with the likes of me trying to understand their product.
2 I'm working on that disparity. Note my findings on the near/far switch settings.
3 Yes I noticed that swapping the rear amp to the front lacked bass.
4 21' by 31' by 8' high. Speakers are on the 21' wall 2 feet in from the side walls

I sat at the MLP and had someone change the settings between near, far, neutral. I ended up with neutral setting but I have a larger room and not confined by space limitations. I would assume most people would be either near or neutral based on room constraints.

Correction: My room is 13' by 22' not 31' x 21' as above. Must be going Sydlexic. Speakers are on the 13' wall.

Try moving them (measured from side wall to center of front tweeter) 3 foot from side walls, and 22 inches from back wall (measured from wall to front center of tweeter) and try MLP at about 8 feet. Put DSP on near 1. Try toe in so right speaker passes to the right of your right shoulder and same for left side(passes to the left of your left shoulder). See if that opens up soundstage and imaging.

From the manual:

The location of your new Axiom LFR1100 speakers will significantly affect the sound quality you experience in your particular room so take care to position them correctly. Since the LFR1100 is an omnidirectional speaker with active drivers located in both the front and rear of the cabinet you will want to keep some space all around your LFR1100s. Around twelve inches (300mm) would be considered the neutral position. If you need to place them closer to or further from the wall or corner than this your DSP box does have a switch on the rear panel labeled “Boundary Compensation”. Around 8” (200mm) from the wall would be “Near 1” and 6” (150mm) or closer would be “Near 2”. If you are more than 24” (600mm) from the wall “Far 1” should be used and more than 48” (1200mm) would be “Far 2”. Th e “Boundary Compensation” switch can also be used to adjust for highly reflective or highly damped rooms. A highly reflective room may be more suited to the switch being in one of the “Near” positions and a highly damped room one of the “Far” positions. Ultimately it is best to try various positions in your room and go with what you feel delivers the best performance.

This pretty much covers how the boundary compensation switch should be used based on distance from the rear wall. There no other adjustments possible to the DSP and this is on purpose. The DSP programming has been exhaustively adjusted for optimal sound power response of the loudspeakers.

As craigsub has mentioned, you MUST have amplifiers with identical gain, otherwise the levels to the front and back sections of the LFR1100s will not be as intended and the interaction between the sections can certainly throw off correct imaging and soundstaging.

Thanks,

Andrew

Here is a link to the owner's manual ... https://axiom-manuals.s3.amazonaws.com/LFR1100.pdf

Here is a link that shows exactly what the DSP does - if one knows how to read it. Happy to call you to explain a lot of this to you ... https://www.axiomaudio.com/pub/media/catalog/product/l/f/lfr1100-sp-lw.jpg

I went from M80 to a pair of LFR1100 passive about 8 years ago, so I bought into the technology when it first hit the market. The points I make were what I found and may not be valid for everyone.

The speakers are room sensitive in when I originally got the speakers I was running them in my front room on the main floor that is 12'x14' and they sounded very impressive like you were standing in the same room as the artist performing. But 2 years later I moved them downstairs to my basement to a purpose built room 15'x18', the sound seemed to degrade to the point I thought that something was missing.

I played around with several different configurations, sound treatments but nothing seemed to fix it. Then I started to think it was something with the source. When I changed the pre-amp to an Anthem (had tried a Pioneer, Marantz & Integra prior) The Anthem was like switching on the light switch and the speakers came to life and started to give the sound that I remember from when they were upstairs.

I have since traded those speakers in for a set of the Active LFR1100 with a pair of ADA1500 amps to drive them.