7 replies to this topic

[~Spyne~]

I thought it was about time I wrote a little review on the amp which has been at the centre of my system for the last 2 years.
Audison's monster 5-channel amplifier, from their LRx range was an amplifier I chose to power my (originally) 2-way + sub system, after going through a shortlist which included other amplifiers such as the Genesis Profile 5, Zed Leviathan, Helix A6, DLS A7 and Elemental Designs NINe.5
What I wanted was something that had excellent power on the sub-channel - after coming from a JL1000/1, I wasn't prepared to go down to only 300wrms for the sub.
Running 8ohm midbasses, I also wanted something with at least 100wrms on the stereo channels, giving me ~50wrms @ 8ohms.
This pretty much only left me with the Audison and the Zed. At the time I had a 2ohm subwoofer, so the Zed wasn't going to work, not being able to bridge two channels to a 2ohm load.
So I ended up with the Audison and was lucky enough to find one for sale on the forums at a price I was able to afford.

• OUTPUT POWER (RMS) @ 14.4 VDC, THD 1%:
  
• 5 Ch 60Wx2(4Ω) + 170Wx2(4Ω) + 750Wx1(4Ω)
  
• 5 Ch 50Wx2(4Ω) + 160Wx2(4Ω) + 1150Wx1(2Ω)
  
• 5 Ch 50Wx2(4Ω) + 250Wx2(2Ω) + 1030Wx1(2Ω)
  
• S/N ratio (ref. 1W output):
  
• 50 W Channels: 80 dBA
  
• 160 W Channel: 80 dBA
  
• 650 W Channel: 58 dBA
  
• Distorsion-THD(1kHz@4Ω)A,BCh: 0.01, 0.05%
  
• Distorsion-THD(100Hz@4Ω)A,SubCh: 0.5 %
  
• Bandwidth (-3 dB) A,B Ch: 4 ÷ 62k Hz
  
• Bandwidth (-3 dB) Sub Ch: 7 ÷ 800 Hz
  
• S/NRatio(Aweighted@1V) A,B Ch: 105 dB
  
• S/NRatio (A weighted@1V)SubCh: 87 dB
  
• Dampingfactor (1kHz@4Ω)A,BCh: 200
  
• Dampingfactor (100Hz@4Ω)SubCh: 86
  
• Input sensitivity: 0.3 ÷ 5 V
  
• Input impedance: 15k Ω
  
• Speaker-In sensitivity: 1.4 ÷ 24 V
  
• Speaker-In impedance: 5k Ω
  
• Load impedance MIN: 2Chx4Ω + 2Chx2Ω + 1Chx2Ω

Well on to the review...
As far as power goes, there is literally nothing on the market that competes. The Leviathan comes close, but doesn't have the flexibility of powering 2ohm or 1ohm loads on a pair of bridged channels, and if you just use one channel on a Leviathan, the power is significantly less for subwoofer duties than the LRx5.1k.
I did initially have issues with the sub channel, as the output seemed to be much less detailed, controlled and dynamic than I was expecting. I jumped online and did some searching and came across a few posts on other forums with similar issues. A common fix seemed to be running the LPF on the sub channel. Even if running active from a headunit/processor, enabling the LPF on the amp seemed to do something to the signal processing, resulting in slightly increased output and much more 'control' over the subbass. I gave it a try, and while I was very sceptical (logically, it shouldn't make any difference, particularly if running the amp LPF significantly higher than that set at the headunit), I was surprised to hear that it did make a very audible improvement. I had the car at Phatt Audio Concepts for some unrelated work and had Sam give it a go and he also later told me that he heard the same change in sound as I described. Those Italians sure are a weird bunch in how they design their amps!!

Running 8ohm midbasses, I have found the power output from Ch3&4 (Ch-B) to be excellent, and can only imagine with the right 4ohm woofers, you could get some crazy volume out of this.
The power from Ch1&2 (Ch-A) is supposedly 'biased' towards Class-A circuitry, and while I honestly can't say I could hear anything that would indicate a difference between A/B or A-biased, it certainly sounds incredible. It does everything you would expect a reasonably high-end amplifier to do; it amplifies the input signal with accuracy and plenty of power. Sub-bass and mid-bass is linear, dynamic and detailed, while midrange is clear, natural and very detailed. Highs are smooth, natural and extended.
I've now got this amp powering my subwoofer, Crescendo MB3-N midranges and Scanspeaker Illuminator tweeters. It does an excellent job and results over the last 2 years would suggest there's absolutely nothing wrong with what part the amplifier plays in my stereo set-up.

While I don't use any of the onboard crossovers (apart from having the sub-channel LPF activated well above the LPF set at the headunit), there are PLENTY of controls;
Ch-A: Off/HPF 50-5,000Hz
Ch-B: Off/LP/BP/HP 50-5,000Hz
Ch 5: Subsonic Off/20Hz/30Hz, LPF 50-150Hz
There's also bass-boost on the sub-channel and an option to mix Ch-A + Ch-B to feed Ch 5.

Powering up there are no turn on pops (and no pops when turning the amp off) and for those who like fancy lighting, the Audison logo glows a nice blue when the amp is powered. You can also swap the centre plate around to have the Audison logo at the opposite end of the amp if needed, to suit your install.
If I had one criticism, it's that the amplifier does run on the warm side. But that is the price you pay for packing so much power into a relatively small chassis; 22" x 8" x 2.25"
Overall, a fantastic amplifier that has tons of power and makes for an unbeatable one-amplifier solution.



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[peaandham]

Great review Adam, sounds like it was a great amplifier.

[2LOUD2OLD]

fantastic write up Adam and great photos to match too
how weird that LPF on the sub channel is tho

[SAM77H]

Great write up Adam.
Pity audison havent come up with a 7.1k..............

I would just like to add I was happy with both of mine (have owned 2). I felt they were let down by poor support locally and overseas at the time.
Also I never had the noise issues that are mentioned on some sites.

[~Spyne~]

Thanks guys.

Sam, I've never had any noise issues from the amp either, though can't say I recall reading anything about such issues on other forums.
And yes, a 7.1k would be an incredible amplifier!! 2 x 150-175wrms + 2 x 100wrms + 2 x 50wrms + 1 x 750wrms @ 4ohms

[SQXPRT]

The Audison LRx are nice amps.
I'd use one(or three) if I didn't already have the JL's

[muzzy66]

Still not a fan of the outside appearance of these amps, but the inside sure looks nice!

Then again, Audison amps always have been nicely built, even starting with the entry level SRx models.

[Surefire]

Used to own one of these myself back when I had my Mazda SP23. Great amp which I miss, but I'll have a decent home theatre set up in a few months so that will have to do until sometime in the future when I finally have the coin to get into car audio again.