EVM 12L - cure for 'Ice pick treble' = inductor coil

[bluesfendermanblues]

Hi Guys,

My Dumble clones (#124, ODS and HRM) like to be played through either an open back 1x12 or 2x12 with celestion 12g65.

However, the EVM12L loaded thiele cab I've build, never really sounded as good, due to the excessive top-end of the speaker.

Last night I tried putting an inductor coil of 0.33mH in series with the speaker, which effectively reduces the top-end.....and makes this speaker/cabinet combo sound very close to the 12G65 in 1x12" open back.

The coil is an air coil, that you would use in a 6db cross-over in a PA or monitor speaker. They can be bought at DIY HiFi speaker vendors.

The particular coil used above is a 21 gauge coil (0.7mm dia), but will probably upgrade this to a gauge 18 or 16 (1 mm or 1.3 mm).

[Drumslinger]

bluesfendermanblues,

good to know. what's the DCR, about 1 ohm or less?

Cary

[bluesfendermanblues]

bluesfendermanblues,

good to know. what's the DCR, about 1 ohm or less?

Cary

The DCR is 0.5 ohms and the coil is rated for 100 watt rms, som I guess its underated.

Go for a gauge 16, rated for 300 watt rms. It should put you back around USD 10.

I guess I will put the coil on a switch on the backplate, eventually.

[Structo]

Interesting Claus

So this is sort of like a crossover, but without the added tweeter?

I have two EVM 12L's in parallel (16 ohm spkr for 8 ohm load).

Sometimes I think the fizz I sometimes hear is the speakers themselves.

You may be on to something.

Couldn't a person wind one of these inductors themselves?

Do you know how many turns there is in one?
Would I use one in series with each speaker?

[bluesfendermanblues]

Interesting Claus
So this is sort of like a crossover, but without the added tweeter?
Would I use one in series with each speaker?

Yep, Its half a 12db crossover.......like a snubber capacitor, only on speakers a coil has the same effect as a capacitor has in an amp circuit.

Interesting Claus
Couldn't a person wind one of these inductors themselves?

Not really worth you while, a coil will only set you back USD 10.

Interesting Claus
I have two EVM 12L's in parallel (16 ohm spkr for 8 ohm load).

Would I use one in series with each speaker?

No, since you run two 16 ohms in parallel, you just use a single 0.33mH coil for both.

[CHIP]

Tom, check this out;

http://www.madisound.com/store/product_ ... cts_id=970

[Structo]

Thanks for the link Chip!

No, since you run two 16 ohms in parallel, you just use a single 0.33mH coil for both.

So I would series this one coil in line before the speaker cable splits to each speaker?

I guess for that price I could certainly try it.
I'd just be afraid of losing some of the sparkle or brightness part that does sound good.

[bluesfendermanblues]

Thanks for the link Chip!

No, since you run two 16 ohms in parallel, you just use a single 0.33mH coil for both.

So I would series this one coil in line before the speaker cable splits to each speaker?

Yes

I'd just be afraid of losing some of the sparkle or brightness part that does sound good.

Its not a dramatic change in sound. Its like changing your snubbers from 250p to 330p

[John Edmonds]

I have a EV12L which I use with my Fuchs ODS.
As you say it can be a bit toppy.
I use a "Clearsonic" acoustic screen to calm it down, and it also allows me to crank the amp, even in small venues.
Big advantage is you can remove it if the hall is soacking up the top.

John

[Structo]

Is that like a Plexiglas shield that you put in front of the speaker cab?

Like this?

Kind of spendy! Like around $306?

[img:385:309]http://www.clearsonic.com/assets/guitar/212_6A18.jpg[/img]

[John Edmonds]

yes,
I got it in the UK for about £100...
As you say a bit pricey but only the cost of a cheap pedal.
It's the same one as used by Matt Schofield and many others.

http://www.clearsonic.co.uk/products/acrylics/A2.html

[dmagalhaes]

Try the Eminence Delta Pro 12A. It has a little less top than the EVM-12L. It's probably designed that way for this very reason.

[bluesfendermanblues]

Try the Eminence Delta Pro 12A. It has a little less top than the EVM-12L. It's probably designed that way for this very reason.

How about the old Eminence Kappa EP300? supposed to be the predecessor of the Delta Pro 12A?

[David Root]

I just received a Boogafunk TL806 cabinet with the truck bed liner finish.

What have you guys used as gasket material to seal the back of the speaker basket to the cabinet surface with this hard uneven finish on it? What would you recommend?

I'm thinking about 1mm thick black rubber, I'd have to find some sheet rubber and cut out the gasket. Would foam type be any better?

More on-topic, the speaker I have I got from passfan, it's older, '86, out of a wedge monitor, the OEM version, and it has a paper, not aluminum dome. I would think this would moderate icepick tone, but then he did tell me not to stand directly in front of it either!

[Bob-I]

I just received a Boogafunk TL806 cabinet with the truck bed liner finish.

What have you guys used as gasket material to seal the back of the speaker basket to the cabinet surface with this hard uneven finish on it? What would you recommend?

I'm thinking about 1mm thick black rubber, I'd have to find some sheet rubber and cut out the gasket. Would foam type be any better?

More on-topic, the speaker I have I got from passfan, it's older, '86, out of a wedge monitor, the OEM version, and it has a paper, not aluminum dome. I would think this would moderate icepick tone, but then he did tell me not to stand directly in front of it either!

My re-cones had foam on the back of the speaker that looked much like weatherstripping. You might want to try that.

EVM's never had metal domes that I know of. The metal actually doesn't make the treble as much as you might think, it's just a characteristic of the speaker to have a strong high end.