Fitting Mitchell Donuts - Help!! **Now with Pics**

[fox5150]

Hi Guys - I hope you can help...

I know at least one of our esteemed brethren has done this (calling Plan-X!!) so hopefully I will find the answer. I've fitted a new Celestion Gold to my LSS today. Whilst I had the speaker out, I thought I would measure the baffle so that I can get the Mitchell Donut ready - see http://www.thegearpage.net/board/showthread.php?t=470956 if you're not familiar with this.

However, when I took the speaker out, I noticed that the baffle is not flush to the speaker grille, but there is another gap of about 1/2" - 3/4". In the instructions, it says to "plug the gap between the baffle and the grille". Now this is a bit tricky with the LSS as there is not only the gap to contend with, but is also two pieces of wood between the baffle and the grille at the top and the bottom of the circumference (about 4" each). So question is, do I just plug the baffle or extend the foam into the open areas between the baffle and the speaker grille.

Help!

Thanks,

Simon

 

[TimeSignature]

Do you have a picture of what you are talking about?

I have read all 40+ pages of the thread several months ago and even ordered the foam from McMaster! Cut the three inch hole, blah blah. Even bought the 3M adhesive spray (which I actually didnt need.)

I tried the Mitchell Donuts and found that it did nothing except reduce the high end slightly on the highly beam-y Fender supersonic.

Most people say they work so hopefully you'll hear a difference.

 

[fox5150]

Hi - thanks for the reply!

I knew I should have taken pictures when I had the speaker out - bugger...

 

[plan-x]

Gap? The gap was neglegible on my LSC, maybe a 1/4". I was a little worried about it at first, but after close examination I realized the grill frame is screwed in flush to the baffle, all sound has to come thru the inside of the grill frame, not around it, thus putting the foam in the frame will do the job. I used the 3/4" foam, shaped it to fit inside the internal grill frame(also 3/4"), cut it a skosh larger or wedged so it would hold itself inside the frame. It will work, as it does on all my cabs.

They come in 12" squares, if you can place it over the speaker hole flush on the front of the baffle and replace the grill with no problem, then mount it that way with some scotch spray glue. But I don't think there's enough room and the grill will start crushing the foam as the screws are tightened.

Here is the "insert in grill frame" method on my lopoline 2x12. Pig on top. By far the easiest way.

And Jay Mitchell's glue to grill method on my detuned cab.

 

[fox5150]

Thanks for the responses!

I had to get up early this morning as I'm expecting a repairman this morning - and I'm on holiday, doesn't sound fair! I decided to take the speaker out and revisit how I'm going to fit the Mitchell Donut. So the speaker comes out and I get a torch to have a look at the gap between the baffle and the speaker grille. Quite an awkward shape to replicate, so I thought I'd see about taking the front off so that I can use it as a template. This turned into quite a saga! I spotted six screws that looked like they were holding the front panel on so I undid a couple to see what would happen and yep, they were holding the front panel on. Trouble is, to get at the last 3 screws I had to take the amplifier unit out. Anyway, whilst I'm busy cutting out some foam, I thought someone might get a kick out of piccies of a LoneStar Special in pieces!

 

[fox5150]

Well it's fitted now. I'm not going to post my findings yet as from what I've read, there's not that much difference when using it at home. I've got band practice Monday night, so will report back then how it went. In the meantime, more piccies of the install and finished product!

 

[plan-x]

Good job! You had a piece large enough. The way you see if it's working is to walk around the room while playing. You should notice the sound/tone is very even pretty much anywhere you stand. Allowing the same mix from all places, on stage, side stage, in the audience etc. Some are ultra critical of the effect, but from my experience, it does what it is supposed to do pretty well. Rather have it than not.

 

[fox5150]

Fortunately I ordered two 600x600 pieces; one 12mm, one 19mm. It was more economical this way. Also allows me to do any other amps I might buy in the future!

I have noticed the change in my rehearsal room at home and it's quite a significant change. The on-axis sound seems less harsh but still retains the character of the amp. Most importantly, the off-axis sound has changed, for the better. It's certainly not as clear as right in front but the overall dispersal is much more even and gives a truer representation of the on-axis sound than before. I'm quite intrigued to see how effective it is at practice and how the others get on with it.

 

[MusicManJP6]

You guys have me very curious. I read Jay's directions on TGP thread.

This the right stuff?:

http://www.mcmaster.com/#85735k72/=4kph2u

 

[TimeSignature]

Yep, thats it.

 

[fox5150]

You guys have me very curious. I read Jay's directions on TGP thread.

This the right stuff?:

http://www.mcmaster.com/#85735k72/=4kph2u

Before you order it I would check out exactly what you need to do to your cab/combo to fit the donut. I was lucky that I had ordered too much for what I should have needed. Turned out I need about twice what I thought; rather than a 12" x 12" piece, I needed approx 24" x 12".

 

[stephen sawall]

Looks good.

 

[BoogieDown]

Looks good. The only thing that worries me about trying something like this is taking the amp all the way apart (it's easy to put back together. But it just seems likens pita) and that it seems similar to puttiong a blanket over the speakers. Seems a little counterintuitive.

 

[stephen sawall]

It does not sound like putting a blanket over the speaker. It sounds like the speaker of axis and sounds the same all over the room.

 

[TimeSignature]

The Mitchell donuts do apparently tame the highs a bit, a sound similar to throwing a blanket over the amp. You will have to readjust your treble. However, the physics behind the Mitchell donuts are quite different than just throwing a blanket over the speaker. The total end result is different as well.

Check out the super huge thread on speaker directivity and Mitchell donuts.

http://www.thegearpage.net/board/showthread.php?t=470956

 

[stephen sawall]

I was one of the first to do this to my cabs (4 cabs) over a year ago ..... I do not know who came up with the blanket phrase..... But that is not accurate at all. Who ever said this .... I do not think they tried it.

It does not in any way sound like a blanket over the cab to my ears. I did not need to change my tone control settings. It did not change the sound enough to do that for me. Some did .... but not much.

What it does is make the sound the same every place in the room and makes it the same as being off axis from directly in front of the cab.

If you stand by the side of your cab without the donuts ..... this is what it well sound like every place in the room with the donuts on.

The benefit of doing this is no matter where you are on stage the sound is the same. The crowd well here the guitar the same as you no matter where they are in the room. It kills the beaming effect of being directly in front of the cab.