What would we know? This is a "a subjective forum with utterly clueless posters" according to the MD.
...active ones with DSP which deal most elegantly with all the phase and crossover issues that the head salesperson on that 'other' forum would prefer to otherwise gloss over....
There's no crossover to the sub so intermod distortion is unaffected by its presence.
I would suggest boom problems are quite rare with AVI actives.
I also don't share your confidence in the ability of DSP to deal with all the crossover issues.
Main: SqueezeBox Classic>AVI ADM40
Second: SqueezeBox Touch>AVI ADM9RSS
(also posted on Avi forum)
Well, I got a box through the post today...
Yep, the Avi sub.Opened it... 2 minsplugged in...1 min.
It's surprisingly small. Slightly wider than my BK, but shorter and narrower.It's a good weight...meaning I can carry it pretty easily
So, it's been on for a couple of hours now.Impressions and comparisons...
Difficult this as both are excellent subs.The Avi sub seems more Hi-fi. There is less overhang on bass notes...tighter. It reminds me of my old MJA pro 50, but bigger and more capable of high SPLs...that one was excellent and tight though, within limits.It definitely suits the speakers 100%, no impression of there "being" a sub. But then I got that with the BK also.One thing I noticed with both subs, and moreso with the Avi,is that it has what must be a psychological effect of reducing any boom.When I first set up my 9RS I got boom. I did sort it out with positioning, but always got the impression that they were on the brink, like they were trying too hard in the bass...certainly with my collection of dub-bass like electronica.Nothing major mind you, but the addition of the sub actually seems to make the whole thing more evenly balanced.
I have only tried with music, but my impression is that the BK will go a little deeper, albeit with not quite as high quality.So, for the ADMs and music, the Avi sub is a clear choice.
I can't comment on films as this is an audio only setup, although there is a TV there for the moment, that isn't used...so I may give it a whirl at some point.
One thing that puzzles me is why the sub is not marketed separately. It would make a fine, high quality sub for any speakers. And although BK have some great subs, the Avi would definitely compete on quality with similarly priced and more expensive subs in the market...Velodynes and suchlike.
I would still recommend the BK at its pricepoint. It is still an excellent sub, and is fantastic for movies, and pretty darn good for music. But if price difference is not a major issue and you want the best from the speakers, then the Avi would be the one to buy, especially if music is the main priority (remembering I haven't tested it for movies).
If anyone is interested, I have the crossover at 60Hz (it was at 100Hz when it arrived!) and the gain is at around 11 o'clock.
Good review SIR
I would opinion that the boom with the AVI's minus the sub, would be due intermodulation distortion reaching fairly high levels with the bass/mid driver having to handle both midrange and bass at the same time, especially when the level goes high.
Despite having been stated otherwise on that 'other' forum, there are definite technical advantages to three way speaker systems, over two ways in that regard - especially active ones with DSP which deal most elegantly with all the phase and crossover issues that the head salesperson on that 'other' forum would prefer to otherwise gloss over.
Also, no matter how good a driver it is, their are limits in terms of excursion, and one cannot beat the laws of physics.
For movie use, have you heard any of the digital drive high end Velodynes, like the DD15 or the DD18 for example - or another high end US sub, JL Audio Fathom.
I think for movie use, one would find them extremely difficult to beat with anything that is manufactured in the UK.
99.9% of speakers that boom is to do with port tuning frequency exciting the room modes. The same speaker can boom in one room and be bass shy in another its nothing to do with the output of the speaker. If you think you have a boomy speaker go and take them to the middle of your garden and play them there. Then tell me they boom.
Good point - I agree - i tend to forget though, as I don't have speakers with bass relfex ports, and the bass response of mine can be tailored to room positon/placement by dip switches attenuating the bass output. And no, I don't have issues with bass boom...
Well yes, it's pretty rich coming from someone who is a business entreprenuer and salesman, with no tertiary audio or electrical engineering training whatsoever to the very best of my knowledge.
Surely the sub doesn't run full range? Or are you saying the speakers run full range, regardless of whether the sub is connected or not, and the sub has a simple low pass filter?
The OP said: "If anyone is interested, I have the crossover at 60Hz (it was at 100Hz when it arrived!) and the gain is at around 11 o'clock."
Neither, the speakers run 'full range', and the sub has a variable (not simple) low pass filter, controllable both for level and frequency response, so that it may operate below the main speakers, and yet take account of room response too. Crossover distortion is therefore avoided.
The AVI volume control, controls the signal level to the main speakers, and the sub signal, in synchronisation.
Thanks for clarifying that.... it sounds an excellent arrangement...
actually it doesn't sound like an excellent arrangement. it sounds more like a lost opportunity or ommision. in every other active sub-sat system I'm aware of there is a lowpass (to the sub) - highpass (to the mains) filtering applied. this makes much sense to cut off low frequency content from reaching the mains woofers. 6.5' drivers are not meant to handle low bass. if they do then system THD in low bass rises significantly, especially at highish SPLs.
I was realy amused when I found out that AVIs don't use any highpass filtering on their mains. since they are already active and controling unit is implemented in one of the mains I would have imagined that by slightly modifying the xover it's silly easy to implement high pass for when the ADMs are used in sub-sat system. for instance there could be a sub out activated by a flick of a switch. when that's done the internal xover network would become 3-way. the lowest frequency content would have already been filtered out for the sub so a simple LFE input would only be necessary.
in most other sub-sat solutions I'm aware of the sub receives full frequency signal and sends highpassed portion to the sats. in either case you gat a true 3-way system whereas in case of AVIs sub-sat as it is now it's more like 2.5 system.
Giro, InTheGroove, Digit, ClassicOne, MG12
and the sub has a variable (not simple) low pass filter, controllable both for level and frequency response
actually this is a simple low pass filter for a sub in that way every other sub on the market will be supplied with at least similar solution to help blend the sub with the rest of the spaeker system. variable lowpass filter and gain control are an absolute minimum in a competent sub so as you see AVIs here don't do any extra work over what's required.
some more capable subs would have parametric EQ implemented to help smooth out rooom nodes. some even more capable subs would be DSP controlled in order to virtually eliminate room nodes. this is what could be caled "not simple" xover.
fortunately vast number of electrical engineers do share JMac's confidence in DSP controlled speakers. thanks to DSP more speakers appear on the market which despite the fact they are multiway jobs they show school-book step response behaviour. this is only achievable for a single full range driver speaker or a multi-driver speaker with perfectly time-aligned drivers. you could achieve similar performance with an analog xover (passive or active) too but doing these things in digital makes the whole job much easier and the end results are virtually free from variations induced by quality of analog components.
on top of that you get full control over speaker frequency response limited only by capabilities of used drivers and unmatched control over driver movement which is proved in impuse response test by means of better suppresed driver ringing. and if you could get DSP speakers with digital inputs and digital power amps (like in case of Grimm Audio's LS1s) you get the benefit of keeping the signal in digital domain as long as it's virually possible, which will always be a good thing.
what's not to like about DSP contolled speakers?
Dont digital filters have their own problems?
Which might lead one to suppose that AVI have decided against it for a good reason.
This is quite true, The Dark One has spoken at length about it.
However, in my experience, few of the hi-fi subs that I have seen and used apply high pass filtering to the main speakers. There was a thread on here recently where someone wanted just that, in order to improve the power handling of his main speakers.
I had a look around and ended up suggesting the Adam subs which have an 85hz filter for the mains. This may still be common in some models but the more obvious brands I tried did not have it.
We do so many shows in a row,
And these towns all look the same,
We just pass the time in our hotel room
And wander 'round backstage,
Till the lights come up, and we hear that crowd,
And we remember why we came.
I thought the adm40's did have a high pass filter set at 100hz when you use them with the avi sub.
HiFi. Arcam cd92,a85,p85 bi-amping Ma rx6, kimber silver streak & 8tc cables and r/a mains.
A/V. panasonic plasma, sony av amp. mordaunt short premier, rel q150 sub.
The only fully dsp speakers I have heard were meridians 8000's i think, and I must say I found them a bit meh!
© 2014 Haymarket Publishing