Beam Blockers

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drz400
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Re: Beam Blockers

Post by drz400 »

angelodp wrote:Any of you guys use this device in your amps..... beam blocker.

ange
It prevents me from Mic'ing where I like, Duct tape would work if you want to try it :wink:
Last edited by drz400 on Fri May 01, 2009 3:50 pm, edited 1 time in total.
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Rimy
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Re: Beam Blockers

Post by Rimy »

i had the possibility to try the foam-donut last night in a live situation at a concert with my band.
and i have to say, i didn't like them.
honestly, at home they are great. even if you play your amp very loud.
maybe even in the studio for some recording. but for me definately not for concerts. i couldn't get trough with my sound. not enough bite to it and too muddy with no harmonics on top of the note because they get swallowed from the drummer and the guy on the hamond.
so i went back to the beam blockers.

ralph
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Structo
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Re: Beam Blockers

Post by Structo »

What foam did you use?

Did you have the 3 inch hole in the middle?
Tom

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Rimy
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Re: Beam Blockers

Post by Rimy »

it was a polyfoam i got in a local foam-store.
and yes, i got the 3" hole in the middle.
as i said i prefer the sound with the foam for home or studio use,
but not for live settings with a band.

but thats only my taste.
maybe other like the sound with the foam better, even in live situations.
and for the price of the foam it's worth giving it a go anyway. :)
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Structo
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Re: Beam Blockers

Post by Structo »

The reason I asked what foam you used is because from the Gear Page thread it was stressed by Jay that it had to be open celled acoustic foam.

The McMaster #4 firmness foam was the closest to that at about mid point in that thread. Near the end there was another source mentioned that looked even more promising.

So if it wasn't an open cell acoustic foam with the proper firmness it may not have been an ideal experiment. :wink:
Tom

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Rimy
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Re: Beam Blockers

Post by Rimy »

So if it wasn't an open cell acoustic foam with the proper firmness it may not have been an ideal experiment. Wink
that's posibble.
but as i said, i really liked it. just not in a live situation.
Kregg
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Re: Beam Blockers

Post by Kregg »

Since I play with earplugs it's all the same to me after the sound check.
Being that no two venues are the same, wouldn't it be best to carry a few strips of foam around just in case?
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greiswig
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Re: Beam Blockers

Post by greiswig »

This is probably totally off-base, but I wonder if something like this would work as well or better than foam?

http://www.hartandcooley.com/submittals ... 0Model.pdf

It's a bit thicker than I'd like, but then I didn't look very hard. Just trying to get the concept out there...
-g
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Structo
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Re: Beam Blockers

Post by Structo »

So the idea here is diffuse the sound waves with the grill type cover?

Sort of like an AC vent type thing?

Don't know.

What's that newer amp out now that has the weird speaker grill?
It kind of has that directional thing going on with it.

But one thing that Jay Mitchell seemed to stress was that the high frequencies didn't just come from the center of the cone.
He has the science to back up his claims as well.

He said the highs come off all across the cone surface.

His rational why the typical Weber beam blockers don't do much to block the beaminess of a speaker(s) made a lot of sense when I read it.
I'm not enough of a squint to be able to explain it as well as he though.

I think what the foam does is absorb some of the waves and mix them up enough to where when they come out of the foam you are getting a better mix of frequencies than if it was just the speaker and grill cloth.
Grill cloth can also act to diffuse the frequencies and the basket weave type grill covering was mentioned in that vane as well.

So he is not really blocking the beaminess of the speaker but diffusing the frequencies so that they are even no matter where you stand in relation to where the cone is pointed.
So that it sounds the same whether you are right in front of the speaker or off axis from it.
Most said there was still a bit of beam on axis but overall it was better with the foam.

I think the guys that didn't care for it (if they used the correct foam) were the ones that have had there cab pointed at there face for years and years and were used to setting up the amp that way. Adjusting the EQ so it wasn't too ice picky for them.

The trouble with that approach is that then the people that are off axis to the speaker are going to get a much less clear EQ of the speaker.

In the end, we're talking about whether or not a bunch of alcohol inebriated people are going to notice and say to one another that hey, that guys speaker is not EQ'd right.
Generally a crowd of people that are just there to dance or enjoy the music are much more likely to listen to the overall sound of the group and then make decisions whether or not they like the group and their tone overall.

I went to a few stadium concerts back in the day when I was unfortunately in front of the PA stacks and to say my ears were ice picked to death would be an understatement. But that is more due to very high SPL's and not the beam of a guitar speaker.

I remember this one Alice Cooper concert where me and a buddy were kicked off an area where we weren't supposed to be and the only place we could stand was in front of the stacks. I don't think I could hear a thing for three days, other than the constant ringing in my ears.
:lol:
Tom

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greiswig
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Re: Beam Blockers

Post by greiswig »

See, to me it's not so much about whether inebriated people will notice the difference as whether or not I'm hearing pretty much the same thing that other people in the house are. We do gigs that AREN'T bars, too.

I think the foam does absorb some frequencies, but that's unfortunate. What it absorbs, it doesn't re-radiate. Ideally, it should just be diffusing them such that all points around a hemisphere are hearing an even frequency response. So if I'm on stage and I feel like I need to turn the presence up because I'm not cutting through enough, the guy sitting in the first row won't start bleeding from his ears.

But foam has to introduce its own issues. That's why I was wondering about something like this vent cover, that might more evenly control the diffusion without absorbing frequencies and creating phase cancellations to the same degree. As an added bonus, you'd be the only guitar player on your block with a speaker grille like that! :roll:
-g
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mhuss
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Re: Beam Blockers

Post by mhuss »

I like the idea. Perhaps in a deep-set baffle board so you could keep the cloth (which has the added side benefit of keeping dust bunnies out, lol).

--mark
LeeMo
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Re: Beam Blockers

Post by LeeMo »

I'd remove the butterfly damper first, though. :lol:
It actually could work to diffuse the sound pretty well. Who's gonna try it first?

LeeMo
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jjman
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Re: Beam Blockers

Post by jjman »

Very interesting. I only read the 1st page of the posting on TGP regarding this. I drew what I think he is saying regarding the highs and the donut hole and such. All of the arrows represent only the highs. As we know, the lows are not curtailed by the foam.

[img:600:387]http://home.comcast.net/~jjsant3250/Foam-on-speaker.jpg[/img]
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FunkyE9th
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Re: Beam Blockers

Post by FunkyE9th »

A few weeks ago, I went to see Tommy Castro. He was using a Red Plate amp into what I think is a Super Reverb cab. I have to say, it is one best tones Strat tones I've heard. They had a board/wall a few inches in front of the amp. It's just big enough to cover the cab and put a mic in front of the speaker. It looked like material used for cubicle walls. He sounded really good through the PA. Don't know how it sounded on stage though.
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greiswig
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Re: Beam Blockers

Post by greiswig »

jjman wrote:Very interesting. I only read the 1st page of the posting on TGP regarding this. I drew what I think he is saying regarding the highs and the donut hole and such. All of the arrows represent only the highs. As we know, the lows are not curtailed by the foam.
I think you're pretty much right on what you drew, but I think it's only part of the picture. I think a fair amount of high frequency sound makes it through the foam, but gets diffused (pointed in different directions) as it makes its way out of the foam.

The goofball idea about the vent diffuser is an attempt to try to get around some of the HF loss that the foam generates, and to see if maybe it disperses the frequencies in a more controlled manner with less HF loss overall. But it might actually create some strange phase issues that would make it a worse solution. Only way to know is to try it.
-g
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