Comparison ADM9 (9.1) and Quad Actives

[Labarum]

Has anyone been able to compare the ADM9 (9.1) and with either or both of the Quad Actives, adding (say) a Beresford DAC (£120) to the Quads.

 

Could be an interesting comparison on cost and performance.

 

[darrenwm]

Brian,

 

Would the Beresford be used as a DAC/pre and fed to the analogue unbalanced input of each speaker? And the volume control left somewhere towards max?

 

http://www.quad-hifi.co.uk/images/models/22/large_1.jpg

 

From reading I don't think they'll compare...

 

They're much less powerful.

 

They're seem to be described as powered monitors, and there is no reference to the crossover. As we know the ADM9 are 350w each and have a 4th order L-R.

 

http://www.quad-hifi.co.uk/model.php?sector_id=2&range_id=5&model_id=22&content=3#details

 

The B. DAC has no remote or analogue input.

 

I think the overall package will be less attractive and sound worse.

 

[Labarum]

No analogue input is only an issue if you need it.

 

A remote volume control is very nice, but not essential.

 

Quad has two internal amps per speaker.

 

As to the sound . . . without listening . . .

 

Has anyone heard them side by side?

 

[darrenwm]

If you can get hold of some of those Quads on home demo I'm not far from you and could bring the AVIs to put up against Quad/Beresford.

 

[Labarum]

Edit: I miss-read the opening of the post "If you can get hold . . . " and I can't!

 

I don't own any Quad Actives. I was just looking for a comparison. There is so much talk of the AVIs, I just wondered what the completion might be.

 

----

 

PC-FLAC/Beresford DAC/Quad 77 Integrated Amp/Quart 980s

 

Radio via Virgin Media box into Beresford which is clearer than Quad 77 Tuner fed from Virgin Cable.

(Poor reception area so not worth putting up even my 5 element antenna.)

 

[darrenwm]

I believe that Mr AVI has owned most (older) Quad gear and may be able to advise, but expect a biased response! He's probably less than a hour from you, up in Stroud, and I had to go there for a dem as there are no dealers in Dorset.

 

[spinnerbait70]

Ash

I have read that using 2 subs is usually better than just one. Hence the question arises. How would two of your subs work in the 9.1 set-up? With one of the speakers being a slave I can't get my head around the idea of 2 subs with this system.

 

Brad

 

[darrenwm]

The ADM9 had two sub outputs, but with the ADM9.1 one was sacrificed in place of an additional toslink input.

 

You could still use two subs with a Y adaptor.

 

JC Brum on here has a few pairs of ADM9s and two subs in the main system, IIRC.

 

[Ashley James]

The ADM9.1s powerful though they are, do not need two of the special subs we've designed for them. One is actually more powerful than the ADM9s and it works exceptionally well with them, it really is seamless and easy to set up.

 

Ash

 

[The Computer Audiophile]

Since low frequency sound waves are wider than the space between a person's ears it is impossible to tell what direction the sound is coming from. With this in mind what would be the advantage of two subs? Volume?

 

I just can't see the value of two subs, but I do have an open mind and I'm willing to listen :-)

 

[spinnerbait70]

at least as far as the wallet is concerned. The 9.1s are so different that when you do the math vs a conventional system you want to have as much info as you can in order to compare. I guess I just need to jump in and order the 9.1 package and go from there regarding the lower 2 octaves. I was waiting for the final review from Chris before I plunged but all indications are leading to a positive review.

Regards,

Brad

 

[Ashley James]

Brad

 

All speakers of the same size have almost exactly the same amount of bass if you take them to an Anechoic Chamber and measure them properly. Or if you measure them on a scaffolding tower in a country garden on a quiet day as we did! This is because they all have the same impedance match with air.

 

The port or chosen enclosure is simply a revolting roaring noise centred on one frequency that can delude you into believing you're hearing more bass. You aren't when you measure it, or you are, but not by as much as you think. It's time not amplitude related like the expansion chamber on a racing two stroke or an organ pipe.

 

It's no coincidence that 6" two way speakers that have more bass also have less mid range and are less clear. This is because the bass you think you are hearing isn't. It's time related distortion and it's worse in passive speakers because the amp can't damp them properly. Someone has put a passive crossover in the way and it's resistive so negates the effect of the amp.

 

What this means is that confronted with a decent pair of active speakers whose amps have a damping factor of 10,000 and a considerable amount of headroom (no DC from a clipping low powered one), you're first reaction will be that there's no base at all and the speakers are a tad forward. Then you'll be surprised by the clarity and unusual smoothness (steeper crossover filters than is practical with passive designs) and finally after a period of acclimatisation, you'll realise that the bass is there but more punchy and better defined because we've got rid of the normal overshoot and overhang.

 

You'll also be perplexed by your local and friendly agent refusing to sell you a subwoofer (which will work better than they do with passive speakers because the 9.1 drivers aren't booming) until you've gotten used to your purchase and made sure that you actually need one.

 

With sincere apologies to Chris for using this Forum as an advertorial, I do hope I haven't overstepped the mark.

 

Ashley

 

[The Computer Audiophile]

Hi Ashley - No worries here. The more information the better. As long as the Computer Audiophile readers know you have a vested interest in the success of your products there should be no issues whatsoever. Plus I like to think the readers around here are a bit above average in the intelligence department and they would see right through any manufacturer spouting nonsense. That is a general comment, not aimed at you of course :-)

 

[Ashley James]

Chris

 

That's extremely kind of you and very decent of you not to have aimed the comments at me because I do spout an awful lot of nonsense, though I try not too!

 

Ash

 

[nathan0001]

Hi all,

I have heard and read a lot of good things about the ADM 9.1's, but can't help thinking that the AVI website is just pushing things a little too far ! For example, "The ADM9s change everything because they improve on any two-way passive loudspeaker made ". This is quite a bold claim !! I have read a few reviewers refer to the Proac Response 1SC's as their new "reference" small speaker. Could the AVI possibly better these stunning little speakers? Or how about some Sonus Faber Guarneri Memento? AVI imply that being active means being better, but there is a lot more to it than that according to most manufacturers. The engineering of the enclosure and the drive units clearly being a major factor.

 

And why do AVI quote power output figures for the amps in these speakers but don't state how it's measured?? Most manufacturers quote figures in the region 20 - 20,000hz - I am guessing the reason that AVI don't state the frequency range is because it is measures at 1khz only ?? What is the real 20-20000hz output figure ??

 

Or perhaps I'm just being difficult !!

 

Many thanks!

Nathan.

 

[The Computer Audiophile]

Hi Nathan - Welcome to Computer Audiophile. I think your questions are very valid and I hope Ashley can address them. AVI is a very science & numbers based company, so hopefully we'll get an answer or two shortly.

 

I am willing to bet the bold claim you mention above is not to be taken literally, rather it's a statement of how much AVI believes in its product. I'm giving them the benefit of the doubt for now :-)

 

[Ashley James]

Nathan

 

I can understand anyone who isn't technical doubting our claims, but they aren't as reckless as they might imagine.

 

There are massive advantages in active loudspeakers over passive, but not every designer realises them, so there are lots of indifferent active speakers out there, just as there are passive ones.

 

Ours benefit from the latest and the best drive units made, in that the bass driver extends to a higher frequency than they normally do, which means the crossover can be well below its roll off and conform to classic theory. These are 24dB Linkwitz Riley filters and since the behaviour of the drive unit isn't significantly adding to what they are doing, not only is phase behaviour better, but they are also steeper than practical with passive designs. Normally the output from the tweeter is audible from behind the bass/mid driver down to surprisingly low frequencies and if you turn the volume up on passive speakers they quickly sound nasal and congested by comparison. ADM9.1s are much cleaner for this and other reasons.

 

Passive crossovers add about 1% distortion and active ones about 0.001%, their resistive element reduces the ability of the Amp to damp the cone with the result that you get more overshoot and overhang and boomy bass is the obvious symptom but there is a lack of mid clarity too.

 

Amplifier power output is simply Volts multiplied by Amps equalling Watts, there are no tricks. The massive advantage that the ADM9.1s have is that we know exactly how much current the bass driver draws and that it's nothing like what any stand alone amp we might design is likely to have to cope with. Therefore we can make low current, high voltage amplifiers with much lower distortion than a stand alone amp and these give better sound quality. But that's not all, because the bass amp only has to cover up to 3.4 kHz, it will have less intermodulation distortion too and the same goes for the tweeter one.

 

These benefits alone are massive, but there are more; If you buy a DAC of equivalent performance, a remote controlled preamplifier, a pair of electronic crossovers, 1 x 75 wpc tweeter amplifier, 1 x 250 wpc Bass amplifier and a pair of two way speakers all in separate enclosures, you're going to have to pay up to ten times as much! Metal boxes are the most expensive part of a system. To us it seemed absurd to put a modern DAC and preamp in separated boxes when the two together only required a PCB about the size of two playing cards side by side.

 

There is no question in my mind that the ADM9.1s will do exactly as we claim because, quite apart from my biased view, we are building up an enormous portfolio of testimonials to substantiate our claims. I'll go even further and predict that within a year or two, the vast majority of hi fi systems will be clones. In our opinion It makes no sense to continue to produce piles of separate boxes when the benefits of doing it as we have are so overwhelming. I'm sure that other manufacturers would have done it years ago if traditional hi fi enthusiasts weren't such stick in the muds. Unlike us, they probably realised that traditionalists would go on the offensive!

 

We did originally claim that they'd better passive two way speakers, but now it's beginning to look as though people find them more pleasant to listen to than three way floor standers, our dedicated sub easily provides the required bas and because there is no lower crossover and an inaudible upper one, the sound is nearly as detailed but a great deal smoother.

We're of the opinion that there is currently an accelerated exodus from hi fi as people discover the merits of a nice looking home computer combined with TV. We say this because many of our customers are selling far more expensive hi end systems to buy them. The big surprise for us and them is that I think all have reported an improvement.

 

I apologise profusely for such a strong sales pitch Chris and I thank you from the heart for allowing me to present my case on this excellent Forum. Others have been less charitable and ADM9.1s are more controversial than they should be because IMO, the last thirty years of hi fi has been polluted by a substantial dose of subjective BS, loads of pseudo scientific claptrap has been spouted and massive changes in sound quality have been ascribed to things as idiotic as mains cables. IMO this has caused neurosis, it's confused and it's stifled progress, so when we come along with a good idea that anyone with a scientific background would see as perfectly possible, we come under attack from those with limited engineering knowledge and an unhealthy belief in the "alternative approach".

 

Good on yer Nathan! Give em a whirl you'll be pleasantly surprised.

 

Ashley (at his most bullish!)

 

Much of what I've said is well established and understood technology, so it's worth searching around the net for more general information on the subject.

 

 

 

[shenzi]

Too add to Ashley's remarks, Boothroyd-Stuart's Meridian range has pioneered the active approach for more than 20 years and the designers have made similar arguments. AVI are going one step further. I think a lot of manufacturers will struggle to keep up as they don't have the experience with both amplifiers and speakers (let alone DACs).

 

I've been active (sort of) for ages - I use a single cone driver which gives some of the benefits of the active speaker but, of course, has limitations of its own. I enjoy reading Ashley's comments and getting a regular fix of scientific fresh air lacking from other online forums.

 

[Ashley James]

I believe that Active speakers were born of necessity. Horns give a very uneven amplitude response and nearly forty years ago, big horn loaded studio monitors were used by all. These were mostly passive, but a company called White produced a sort of electronic crossover that could be adjusted to smooth the amplitude response. In the early seventies Rock Groups decided they could earn more money by doing outdoor concerts and variations on these Monitors were pressed into service. They comprised 2 x 15" bass drivers and a big horn and they sound dreadful! Two Australians David Martin and Billy Woodman (ex chief engineer Goodmans and colleague of Laurie Fincham of Kef) had just founded two companies, Dave to make PA for this application and Billy (ATC) to make very high power drive units and they were joined by Tim Isaac from Turbosound.

 

Billy Woodman designed a massively powerful 12" mid driver, Dave designed a short horn for twin 15" and Tim designed some colossal power amps using the new Mosfet transistors and, more importantly, a modern electronic crossover to make this three way system Active. The result was louder and far better sounding because it got the horn out of the mid band. I think Supertramp were the first big name to buy them and everyone else soon did too. Billy Woodman was very much a hi fi man and he'd produced the World's first 1" fabric domed tweeter at Goodmans (Peerless also announced one at the same time), he so liked what it did that he designed a 3" version for the mid range of a three way system and it may never have achieved much if Roger Quested, Adam Faith's studio manager (Dick James Music) hadn't approached Billy to improve their old horn monitors. A dome monitor system was built with an Isaac (ATC) crossover and it caused a revolution. Over the next ten years, most of the UK's major studios bought ATC monitors as did others all around the world including Hollywood, our own BBC and even big Japanese ones. I joined ATC in '85 part time and full time in '87 and had a hand in all this.

 

Needless to say AES papers were presented and it influenced B&W, Meridian and even Linn to produce active speakers and, had circumstances been different, I think they would moved into the mainstream then. Meridian's were the most successful, the others not too good and too expensive. The early eighties was when hi fi lost out to TV's and in particular VCRs. It was also a time when the subjective drivel started to take over and make it more difficult for products to win through on technical and true sonic merit. Terms like "musically involving" still rankle with me today.

 

Hope this is of interest.

 

Ashley

 

[nathan0001]

Ashley,

Many thanks for such a detailed response. I am not the most technical of people but I still believe that power output is more than just volts multiplied by amps for amplifiers. For example, most mini systems / car hifi systems seem to quote power outputs at 1khz, and rather high distortion levels, and not at the 20-20000hz that most "top" hifi manufacturers tend to. How are the ADM 9.1's measured ?? What frequency range ?? Is there anyone else out there that has the knowledge to comment on how amplifier outputs are measured?

 

I have also been lucky enough to hear a pair of Proac Response 1SC's ( that is why I mention those in my earlier post ) and they sounded simply amazing. I am sure that Stewart Tyler ( he was Proac's designer, though may not be now ) could come up with an equally convincing argument for the design of their speakers, and so I guess I will just need to hear a pair of ADM 9.1s myself..........

 

I just can't help but be a little suspicious because of those amplifier output figures not looking quite right to me. And I have always read that high current is what amps need, not low current !!?

 

I hope you can shed some more light on this for myself and others .

 

Regards,

Nathan

 

[Ashley James]

Nathan

There is nothing the least bit suspicious about the power ratings and an amplifier only needs to produce as much current as the speaker can ask for, which in the case of this active speaker is dictated by the minimum impedance of the driver, in this case 5.4 ohms.

 

Passive crossovers are different and many speakers have a nominal impedance of 4 ohms and drop far lower. Each time the impedance halves, the amp must produce twice the power and if it can't it might be damaged, therefore stand alone amps have to be designed to cope with this at greater cost and with higher distortion.

 

If you read back through my first answer you'll see that I talk about the substantial amount of distortion produced by passive crossovers and the limitations imposed on them by the components available to designers. What this means in simple terms is that in passive speakers, crossovers are quite obtrusive and in active ones, they are by comparison, inaudible - hence a big improvement in smoothness and clarity.

 

Trust me, there are no catches, it's just a better way to do it and it would have found favour years ago if it wasn't for the upgrade path. People like to buy a seriously expensive system a piece at a time and you can't do that with ADM9.1s, you have to just fit, forget and start collecting music!

 

I think if you read through what I've said a few times, it'll begin to make sense.

 

Ashley

 

[radar2886]

Nathan, as someone who has had the ADM9s over a year, I can confidently say that there is nothing wrong with amplifiers. I have heard people on other forums ask about the power rating, and honestly I do not understand the obsession. I will say that they are the cleanest speakers I have owned. They can play extremly load without distorting and I can honestly say that my ears and my neighbors give out long before the speakers.

 

 

[DavidJPettifor]

[best Homer Simpson voice]Hmm, ADM 9.1s...[/best Homer Simpson voice]

 

If only (sigh). Well it's good to dream!

 

--

djp

 

[darrenwm]

I haven't measured the amps personally, but my subjective impression is that there is more than sufficient power!

 

I have owned many amps and loudspeakers in the past 10 yrs, and could always hear if an amp was not powerful enough, because the sonic character of the system would change as the volume was increased. Typically the sound would become strident with a lower-powered amplifier.

 

With the ADM9.1 you can turn it up and up and the sound is totally consistent. Because the active configuration is much more efficient one can achieve high SPLs with a amplifier that would be relatively modest into a passive loudspeaker.

 

[Labarum]

I fear the matter is 'orribbly complicated. The loudspeaker is not a pure resistive load - without a crossover it would be (mostly) and inductive load (ie the the amplifier is looking at a coil of wire in a magnet), but with a crossover some capacitors are involved (conductive plates held close together, but not touching, so they store a charge of electricity). This complex load presents a different impedance (that's resistance to an alternative current) depending on frequency. At some frequencies the impedance might go extremely low, placing great strains on the amplifier as it attempts to develop power into a near short circuit. The speaker may have electrical resonances at certain frequencies, but is is yet more complicated than that, for the speaker and it's box are also a mechanical system with mechanical (sound) resonances - these mechanical effects interact with the electrical effects, and the mathematics can get quite amazing. An active speaker reduces some of the complications and ties the amplifier and the loudspeaker closer together. The engineer is able to optimise the compromises better over the whole system and is able to design the amplifier to work with one known loudspeaker.

 

I have only begun the scratch the surface of the complexity, which I do not fully understand myself, and have probably given you a load of half truths in an attempt to say something in not too technical language.

 

But there you go.

 

And yes, the power bandwidth of the amplifier is important. Some say it should be as wide as possible going from DC right up into the radio frequencies (because there are effects that make a difference outside the audible range), and some say it is better to limit the power bandwidth of the amp to the audible range.