AVI DM 10 cabinet quality?

[radiorog]

Hi, following other threads on these speakers recently, I'm curious to what people might think of the quality of build in the DM 10's. I don't know much about actives, but I'm guessing having more electronics inside the unit produces more complications to do with the resonances and the such and the sound quality of the speaker. Therefore I'm also guessing that some serious thought needs to go into the design and quality of the cabinets. Surely it must be harder to brace the cabinet adequately?

What's peoples thoughts on the quality here?

Cheers.

 

[davedotco]

Hi, following other threads on these speakers recently, I'm curious to what people might think of the quality of build in the DM 10's. I don't know much about actives, but I'm guessing having more electronics inside the unit produces more complications to do with the resonances and the such and the sound quality of the speaker. Therefore I'm also guessing that some serious thought needs to go into the design and quality of the cabinets. Surely it must be harder to brace the cabinet adequately?

What's peoples thoughts on the quality here?

Cheers.

For that really not to be a problem, building solid cabinets in DM5 or ADM9/10 is really not going to be an issue. Bigger cabinets would be different.

This is why, for hi-fi use, I think the smaller Yamaha HS7 is a better all round speaker than the bigger and more potent HS8, cabinet issues I think.

 

[jcbrum]

Martin Grindrod, AVI's Chief Engineer, is a military class avionics designer, by training, formal qualification, and previous profession.

The ADM electronics use surface mount technology all rigidly mounted on a heavy metal backplane which also acts as a heatsink and chassis. There is no requirement for the electronics to be mounted on the woodwork, which is specifically designed for correct acoustical response. The cabs are filled with acoustical fibre to produce the required damping of the internal air spaces, and the thick metal plate forms most of the backplane of the speaker. They employ lightly loaded front porting.

JC

 

[Morgunner]

My 9 year old ADM9s are still immaculate. Cabinets this size simply don't need extra brasing, thick mdf and modern glues make them bricks. And they are UK built. The DM5s are a clearly "cheaper", having a plastic back plate glued on, so drivers need to be removed to get in. May sound fishy but the truth is we audiophiles have been manipulated for decades to think these things affect sq far more than they do. Wouldn't it be utterly stupid for any serious audio manufacturer to get the electronics just right and then screw it all up with bad cab design and build? Yes, and therefore they don't.

 

[radiorog]

Thanks for your answers.

 

[richardw42]

From a cabinet (not internals) POV the DM10s I had were really well put together and were flawless. Not sure who builds them, I think Timberworx did the ADM40.

 

[davedotco]

From a cabinet (not internals) POV the DM10s I had were really well put together and were flawless. Not sure who builds them, I think Timberworx did the ADM40.

Timberworx.

Good quality, nice veneers but no piano laquer, which rules it out for me.

 

[thewinelake.]

Could one get a piano black lacquer finish applied afterwards?

 

[davedotco]

Could one get a piano black lacquer finish applied afterwards?

You would have to strip out the drive units and tha amp panel, get it painted then re-assemble.

I investgated this put thought it too expensive, £200-300 per enclosure, from someone who's business is refurbishing pianos.

 

[Deleted member 108165]

This is particularly beneficial when the amplifier is mounted to the rear panel as it breaks up the waves that would otherwise bounce off the flat rear panel in a passive speaker and pass partly uneffected straight throught the speaker cone.

Unless you're into transmission line passives of course *biggrin*

 

[spiny norman]

Unless you're into transmission line passives of course *biggrin*

Or any passive speaker that's properly damped and/or uses a cabinet design that's not a simple rectangular box.

Mind you, if that's what the vibration inside the speakers is doing to the amplifier, could you get the same effect by using a passive set-up and shaking your amp in time to the music? Should be easy enough with a NAD D 3020 or a Cyrus integrated or whatever; might be a bit tricky with a pair of Krell monobloks. ;-)

 

[davedotco]

Unless you're into transmission line passives of course *biggrin*

Or any passive speaker that's properly damped and/or uses a cabinet design that's not a simple rectangular box.

Mind you, if that's what the vibration inside the speakers is doing to the amplifier, could you get the same effect by using a passive set-up and shaking your amp in time to the music? Should be easy enough with a NAD D 3020 or a Cyrus integrated or whatever; might be a bit tricky with a pair of Krell monobloks. ;-)

Are in my experience quite microphonic. I have certainly seen examples that 'sing' when a signal is applied, in some cases it is perfectly possible to identify the track being played, you can actually sing along.

Of course transducers usually work both ways so the vibrations inside the cabinet will produce current in the circuit...

 

[steve_1979]

Hi, following other threads on these speakers recently, I'm curious to what people might think of the quality of build in the DM 10's.

They're a bit plain looking as they're just square boxes with a grill and badge. They're well made though and have good quality vaneers. No complaints there.

The metal rear panels have what look like good quality sockets on them. These are panel rather then board mounted too. The benefit of panel rather then board mounting is its more reliable and if anything does go wrong it's likely to be easier and cheaper to repair.

I don't know much about actives, but I'm guessing having more electronics inside the unit produces more complications to do with the resonances and the such and the sound quality of the speaker.

One of the rarely mentioned benefits of active speakers (this includes most actives not just AVI ones) is that they have the amplifier mounted inside the enclosure. The irregular shape of the internal amplifer helps to break up standing waves which improves the sound quality. This is particularly beneficial when the amplifier is mounted to the rear panel as it breaks up the waves that would otherwise bounce off the flat rear panel in a passive speaker and pass partly uneffected straight throught the speaker cone.

 

[steve_1979]

Mind you, if that's what the vibration inside the speakers is doing to the amplifier, could you get the same effect by using a passive set-up and shaking your amp in time to the music?

It's easy enough to test for yourself if you want to see how microphonic amplifiers are.

Just give your amplifier a firm tap while playing music. Can you hear any difference? No? It's nothing to worry about then.

 

[spiny norman]

It's easy enough to test for yourself if you want to see how microphonic amplifiers are.

Just give your amplifier a firm tap while playing music. Can you hear any difference? No? It's nothing to worry about then.

I'll take the ddc version, thanks. There's a difference between the effect of a firm tap and that of continued vibration, even if I am fairly confident a lecture on guided missile systems is already being prepped for deployment as we speak. ;-)

 

[davedotco]

I was talking about passive crossovers.

It first came to my attention when servicing a set of vintage Tannoy Monitor Golds(or maybe Reds). I was fitting them into new enclosures and failed to connect the 4 pin connector and cable that takes the bass and treble signal, from the crossover to the two way drive unit.

Applying a music signal, the crossover in it's own little (hard plastic) enclosure could easily be heard singing along. This was the most obvious example I have heard but many other designs do something similar, but less obvious.

 

[steve_1979]

...even if I am fairly confident a lecture on guided missile systems is already being prepped for deployment as we speak. ;-)

Well since you brought it up (and I'd hate to disappoint you ) for anyone reading this comment who was wondering what spiny is referring to.

Martin Grindrod, the designer at AVI, used to design the electronic guidance systems which are used in guided missiles. So it's safe to assume he's an expert at designing elecronics which aren't adversely influenced by vibrations.

 

[steve_1979]

I was talking about passive crossovers.

Ha!

*biggrin*

 

[steve_1979]

Are in my experience quite microphonic.

I put it to the test once and tried very hard to get an amplifer to react to vibrations. No matter what I did* I could not get the sound to change.

* this included hitting it hard with a rubber mallet as well as picking it up with both hands and vigorously shaking it! And before you ask. Yes I know. I'm bonkers. *wacko*

 

[spiny norman]

I was talking about passive crossovers.

hat happens when you start a sentence in the heading and continue it in the body of the message while apparently responding to something you've quoted.

 

[davedotco]

I was talking about passive crossovers.

hat happens when you start a sentence in the heading and continue it in the body of the message while apparently responding to something you've quoted.

*biggrin**biggrin**biggrin**good*

 

[spiny norman]

*biggrin**biggrin**biggrin**good*

*biggrin*

 

[spiny norman]

Well since you brought it up (and I'd hate to disappoint you ) for anyone reading this comment who was wondering what spiny is referring to.

Martin Grindrod, the designer at AVI, used to design the electronic guidance systems which are used in guided missiles. So it's safe to assume he's an expert at designing elecronics which aren't adversely influenced by vibrations.

You never disappoint when it comes to your knowledge of the Gospel.

I guess that also means he'll be great when it comes to speakers able to destroy your house with pin-point accuracy from hundreds of miles away, then? Or did the results of his avionics designs surprise him as much as those of the speakers he apparently never actually listens to when he's designing them (at least according to the low-budget PT Barnum) ?

 

[bluedroog]

I love the build of the enclosures in my Event Opals, cast from metal they're as solid as you'd like and then some. In addition they are curved.

 

[steve_1979]

I love the build of the enclosures in my Event Opals, cast from metal they're as solid as you'd like and then some. In addition they are curved.

I know what you mean. The design of the Opals enclosure is one of the best that I've ever seen.