SBL X-over inductor DCR values

[James]

Postscript

The other thing to note is that higher DCR decreases the acoustic output of the midbass relative to the tweeter, so the overall amplitude and tonal balance will be skewed to begin with. The converse is also true, and significant reduction in DCR will increase the output of the midbass and may give the impression of more fulness. Just another $0.03 to add to your experiments by ear.

James

 

[markt]

James,

I was tempted to order a set of bass inductors with the lowest DCR possible for just those experiments, but then after glueing down those inductors I started to get the fullness I experienced going wide open, (I know, it should be the reverse) so I suspect level has much to do with it, I think level to the bass was slightly lower with extra DCR and with the extra wire and inductor flailing around unsecured giving a sense of leaness.

With this in mind I think providing I can keep the inductor from vibrating at all (I'm really going to town on this one) I can get that fullness without resorting to changing the values, it might just be that the reason some of these large massy foil type inductors sound the way they do (I'm guessing, can you tell?) is because of their sheer bulk lowering self resonance, there is an MLSSA graph on the mundorf website in the foil inductor PDF that shows some comparisons.

Now if I could get an ordinary air core to do that...

 

[markt]

And on to the next...

Received a little white box in the post this morning, the Caddock MP930 resistors for the x-over are here!

1 ohm, 6.8 ohm, 8.2 ohm, 27 ohm, this little lot will cost around £50 per set plus heat sinks for a pair of SBLs (!!!!!) including postage from Canada at Parts Connexion, no fear though, I know what a good fast (very low self inductance) metal film can do in amplifiers.

In they went, one position at a time and a listen in between, the 1 ohm in series with the tweeter first, then the shunt/ground 27R, then the cap connected/ground 6R8 and finally the bass sections only ressy, the 8R2.

Every time, each and every time it was clear that the information had come forward, even closer than before and less smeared than before, wayhay!!!!

Expensive?

Nope.

 

[markt]

Wilkys Brass collars work a treat, talk about zip!

The treble air-core is clamped down with stainless washers to add mass inside its bronze shroud.
The treble caps look to be radiating into one another, in fact they emit virtually nothing, the end caps on the enshrouded supersounds are sheilded with some sort of metalic gunk (I had a look inside one of them) so I took some liberties with positioning, better that they face low power parts than high power ones in the bass section across the board.

The resistors.

Time to make the second one now.

 

[Wilky]

Far canal.......

 

[markt]

Thought you'd like it.

 

[steveinspain]

Mark - still got problems getting online, and hotmail is just not happening, but have now seen theses pictures - As wilky says...!
Just how big are these things, and if they sound as good as they look...

Can't wait !

 

[markt]

Worry not Steve, they fit nicely on the back in the same holes, already listened to it and made comparisons with some mono recordings (only one made so far) one boo boo though, I spaced the input sockets away from the inductor using the old style Naim plugs, if you have the new style ones (with tabs on both sides) then the top neg tag will have to be filed off.