Ook,
So the ortho mascot has been helping me all day to damp these Aiwas. I have been yo-yo-ing around the equilibrium point.
I can in fact get a sound that most would probably find awesome, BUT, being the basshead I am I have tried to get to the point where I have a smooth clear sound AND deepest bass. (Instead of settling for trading off the deepest bass).
I nearly went crazy doing this (as could be seen by my last post erheemm
).But I think I have MOSTLY done it. I'll post where I am before I totally lose the plot lol.
Ok, firstly I think something needs to be mentioned and it's something which will hopefully revolutionize damping for everyone. It's
Ludo's (all credit to him, I just continued the Euro Yammy Wings work) theory of
'Differential Damping'.
This theory works by damping the driver strategically based on where it makes most bass and most treble.
Firstly, you will have to perform first stage damping by damping the cup surface and vents.
Now you can use felt against the rear of the driver to tune the sound to your preference balancing it all around the damping equilibrium point.
Take for instance a Yamaha driver, Ludo figured that the driver is pinched in the centre, therefore most bass is produced as you travel to the drivers outer circumference.
And with drivers such as the large Fostexs' this would work in reverse, with bass more in the centre.
So onto the Aiwa. the first stage damping:
Fostex driver > Red felt (from ericj) flush against driver > Thick grey felt (Smeggy's felt) filling the whole cup > fibrefill to fill the grille dome space.
Here are photos (click to enlarge):
Red felt against driver:
Grey Smeggy felt visible from my earlier damping scheme:
.
Now for the differential damping. I wanted to damp it more and retain deepest bass. So I wanted to damp less in the center.
So between the Red felt and Smeggy felt, I added a donut of Moorbrook, thin dense black felt (this is the magic stuff we used to damp a lot of Yamahas).
Here it is:
.
What this had the effect of doing, is damping the upper mids to treble, whilst having not much effect on damping the bass.
Nice, but to me the bass was too wild and loose still. So here is where me and Ludo disagreed (he thinks its unwise to do this), but I shall show you what I did.
If you look closer at the last photo, you will see in the donut hole of Moorbrook, I have put tightly a small disc of Red felt (the tongue of my ortho mascot
), with a small hole (few mm) in that. I called this Progressive Donut damping.
Basically the damping layer gets less dense as you go to the centre. It is not entirely different than what Yamaha employed in the YH-1000 I think.
The hole was to eek a bit of the deepest bass out. technically it should cause lots of backwave problems, and in most of the schemes, yes it does, this scheme just about gets away with it.
Ok that was a long read, hope it helps someone out there in their damping efforts.
I can now say the Aiwa is vv.good. And any tuning from this point will be using the progressive Donut technique. But I dont see much of a need to untill I get the YH-100 for a showdown.
(PS: About that sound that most would find awesome. Just do the same scheme as above, except dont put the small hole in the small Red felt donut piece. OR have no small red piece. And have the Moorbrook be a disc instead of a donut, and put a small hole (2-3mm) in it)
.
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