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AVI DM10 - Active System

On the contrary, whist subjective assessments can result from often quirky personal preferences, I think that objective assessment based on measurements would show AVI to be a clear winner, if only on distortion alone.

This is particularly apparent by the many assessments and testimonials from satisfied users who say that the clarity and outstanding fidelity is immediately striking by comparison with other systems.

JC
 
You interest in AVI is well known. What you and others think of AVI systems and non-AVI systems is not really relevant, except to AVI fans.

Anyway, I am willing to test it out - where can I audition AVI?
 
jcbrum said:
On the contrary, whist subjective assessments can result from often quirky personal preferences, I think that objective assessment based on measurements would show AVI to be a clear winner, if only on distortion alone.
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JC, you really don't want to open this one up again, do you?! AVI have never published a meaningful spec let alone an actual measurement that can be peer-reviewed in all the time I followed the arguments. I've no idea if anything has changed as I've just no interest in it these days, but last time I looked their "350 watt" plate amps were 50-60 watts tops (based on reverse-engineering PSU size, available heatsinking and the claim they were class AB). You can't rewrite physics, not here on pfm anyway! That is just one of many claims that was shot down by people far more technically minded than you or Ash. My advice is to stop digging as I'll happily allow folk to challenge potentially false claims here.
 
Cav, I hope you do listen and report back.
I would still be interested in comparing AVI to other active systems. I've given up trying to make sense of figures (eg. amplifier power ratings and classes) as they don't seem to be terribly objective.
The more I hear about hifi, the more similar I find it to wine!
 
I haven't got the impression that PFM is particularly anti-AVI but more that they can see through the BS spouted by some. I've had email comms with Ash and he is clearly passionate about his kit but some of his comments are simply ridiculous. You get some of this from other companies (they are there to sell kit after all) but not as much as from AVI!
 
JezmondTutu said:
I haven't got the impression that PFM is particularly anti-AVI but more that they can see through the BS spouted by some. I've had email comms with Ash and he is clearly passionate about his kit but some of his comments are simply ridiculous. You get some of this from other companies (they are there to sell kit after all) but not as much as from AVI!
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It isn't. I just get hugely annoyed with exaggerated claims and shill marketing. I actually like AVI products, if they were honestly marketed (i.e. either with real measurements/specs or subjectively) I'd happily reccommend them to anyone looking for a budget audio system. Beneath all the bullshit and hype it is actually very decent stuff.
 
Tony L said:
It isn't. I just get hugely annoyed with exaggerated claims and shill marketing. I actually like AVI products, if they were honestly marketed (i.e. either with real measurements/specs or subjectively) I'd happily reccommend them to anyone looking for a budget audio system. Beneath all the bullshit and hype it is actually very decent stuff.
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Well said Tony and I completely agree!
 
jcbrum said:
This is particularly apparent by the many assessments and testimonials from satisfied users who say that the clarity and outstanding fidelity is immediately striking by comparison with other systems.

JC
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Excellent marketing copy. Gold star for your jotter :p
 
Tony L said:
<moderating>

Marketing guff removed. Facts only please JC.
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It's a shame you did that Tony, it was simply a reply to Cav, directly answering his question about how to get an audition of AVI loudspeakers.

If you won't allow that info, then I can only suggest he uses the AVI forum for info.

Regarding your request for facts and specifications, that is also available, and easily verified.

JC
 
JC, that's fine as long as people fully understand the AVI "forum" is purely a marketing tool and any posts that are critical or demand hard evidence/measurement to back marketing claims are censored/removed.
 
Tony L said:
JC, that's fine as long as people fully understand the AVI "forum" is purely a marketing tool
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Tony, that statement is factually incorrect. It's an open forum, not heavily moderated (like this one), and there for all AVI users and enquirers.

You might have your opinion, but other people will have theirs too.

You ask for facts, and Cav said this
" As to performance, that can either be on measurement or subjective preference. I doubt AVI would win on measurement."

I replied
"On the contrary, whist subjective assessments can result from often quirky personal preferences, I think that objective assessment based on measurements would show AVI to be a clear winner, if only on distortion alone."

Here are the true facts and specifications published by AVI, by Martin Grindrod, AVI's designer and Engineering Director.

Grindrod wrote:
There seem to be some posters that have real trouble accepting the claims made by Ashley I thought I would just post some facts since I actually made the measurements and did the analysis [AVI ADM9]:
Regarding distortion in crossovers:
I measured a typical 2 Way 2nd order LR crossover designed for a crossover frequency of 3.5kHz using a number of different inductors, using the drive units as loads at 10W the electrical harmonic distortion was typically 1% (-40db) for the iron cored inductor samples and 3% (-30dB)for the ferrite cored samples which was a suprise! Measurement frequencies were 1 octave either side of the crossover frequency. I did not use an aircored sample because it was highly resistive (0.8ohms) compared to the drive unit impedance which in itself introduces response anamolies of the order of 10% (-20db) which , since the drive unit signal is in error compared to the input in the passband of the filters,it can legitimately be called distortion. In practice response anomolies are measured with all the inductor types due to their resistance. (This is particularily noticable in 3 way designs where the lower crossover point requires large values of inductance)
By contrast the active filters used in the ADM9s have distortion typically -96dB at the frequencies used above, this means that the active filters in the ADM9s are very much more than 1000 better than the passive crossover.
The mid-band distortion of the ADM9 amplifiers is typically –96dB so even including the amplifier the distortion in the voltage received at the drive units will be better than 50dB lower than a perfect amplifier driving a passive crossover.
Regarding damping factor:
The amplifiers in the ADM9 are optimised for the loads that they see, the output impedance is typically 1mohm mid band, there are two short cables (9”) direct to the drive units.
Now consider a typical passive system, firstly, in order to ensure the amplifier is stable into a wide range of loads it will have some form of output coupling, either a damped inductor or series resistor. Also the typical output imedance is much higher than the ADM9 amplifier since the ADM9 circuit produces an exceptionally low output impedance. Typically the amplifier alone may have an output impedance from 50mohms to 0.5ohms in some cases. Add to that the connector and cable losses, typically 50mohms for 3m of 2.5mm2 cable, and then the crossover losses which may typically be 0.3ohms at DC then the source impedance seen by the bass driver will typically be 0.4ohms to 0.9ohms compared to the couple of milliohms seen by the bass driver in the ADM9.
An important point to make is that in the passive system from a decade either side of the crossover (i.e., 350Hz for the bass driver in the example above) the source impedance rises significantly as the crossover frequency is approached. It is a common mistake to visualise things happening close in around the crossover frequency but in practice things start happening at least a decade away!
I hope this goes some way towards showing that the claims made, not just ADM9s but active speakers in general, are real and factual, correctly designed there are huge advantages in terms of drive unit control and distortion, all this is measurable and is not just ‘an opinion’
I hope this helps in putting this one to bed!
Martin

JC
 
I love the smell of advertorial in the afternoon.

jcbrum said:
Tony, that statement is factually incorrect. It's an open forum, not heavily moderated (like this one), and there for all AVI users and enquirers.
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BS
 
JC, it's just marketing bullshit aimed at non-technical people, people who don't understand crossover distortion is only one very small part of the whole picture (e.g. one radically lower in significance than trying to get bass out of tiny drivers in tiny ported boxes). It is also not relevant to the point I put. Ask him to show actual measurement data to back the outlandish power output claims made for the 5, 9 or 10 amp pack. That will shut him up as you, I and he know damn well he can't!

PS On reflection please don't! Against my better judgement I had a quick read of the What HiFi forum and AVI bullshit is still in full flow. I really don't want it here on pfm. I understand Ash is on a mission prior to flogging the company, but I don't need the hype spreading here. Hopefully the next owners concentrate on the product and choose a far more dignified and credible marketing approach.
 
Tony L said:
PS On reflection please don't!
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Fair enough, with your attitude it's a ball-ache anyway. All the info is readily and freely available elsewhere.


Tony L said:
Against my better judgement I had a quick read of the What HiFi forum and AVI bullshit is still in full flow. I really don't want it here on pfm.
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Try the several Facebook groups as well. AVI is very popular modern equipment.


Tony L said:
I understand Ash is on a mission prior to flogging the company, but I don't need the hype spreading here. Hopefully the next owners concentrate on the product and choose a far more dignified and credible marketing approach.
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Ash isn't "flogging the company", he's over 70 now and is simply implementing a phase of normal retirement with a focus on increasing his time spent in caring for his family and his classic car collection. AVI is a very valuable company and has attracted interest from new commercial investors. Professional users are very keen on AVI.


JC
 
No skin off my nose either way, Still. Looks like Romulus (OP) will be able to get the info he seeks. Just not here. It's a shame for PF really.

JC
 
Advertorials are of no benefit to pfm. On the contrary, they degrade the site.
 
jcbrum said:
No skin off my nose either way, Still. Looks like Romulus (OP) will be able to get the info he seeks. Just not here. It's a shame for PF really.
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John, you came in a shat up the thread first by trolling and then with spamming sales guff, so please don't be whinging about people challenging you or the reputation AVI have on any forum where folk who actually understand audio technology right down to a bits, bytes, acoustic and electronic level reside. It is a huge shame as the kit is genuinely better than the bullshit that surrounds it, yet every time they are mentioned in you come with the same old pitch.
 
Tony, you've got a bee in your bonnet about Ashley and AVI, as everyone can see, and for no reason at all really.

You perhaps need to get out a bit more. Hope your foot gets better soon.

JC
 
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