Weber Beam Blockers

[WhoJamFan]

Anyone else using them?

[C-4]

I use one in a Diezel Einstein combo, which came with a Celestion V-30.

It improved to sound by taming the focused highs eminating from the cone.

[mrmatt1972]

I used to on an amp with a ton of treble and a cab with a single 12 that was very mono-directional. It helped to ease the highs and spread the sound as advertized.

[Pietro]

Made a noticeable difference in my old Super Sonic 60.

[gmann]

I'm using one on my '59 tweed Pro. I've used several of their 10" ones in the past. They work as advertised.

[908SSP]

I make my own for $2 each. Aluminum from Home Depot and speaker dust coil covers from Parts Express. As many as I use I couldn't afford them from Weber.

[Norjef]

Smoke and mirrors, dudes - check out Jay Mitchell's foam donuts instead.

[psychodave]

I got 4 tone bras for free a few years ago and I think they work great. I used them on some G12-T75's and they got rid of the harsh top end. I agree with 908SSP...you can make some for super cheap.

[Madison]

I have two hanging on the wall (to the right of the Fender parking sign), they look cool up there! And no, I don't care for them in front of a speaker.

http://img.photobucket.com/albums/v631/MadisonB/IMG_0011.jpg

[Kyle Ashley]

I had them in my Bogner cubes and took them out. They seemed to tame the spiky highs a bit, but the more I heard them, the more it seemed phasey....so I yanked them.

[solitaire]

They make a difference but they don't operate as claimed. I've been using the medium and large size versions. Donuts are the way to go. ;) - but let's not derail this thread over it, alright.

[neastguy]

I use them and like them...

[epluribus]

Yup, Jay Mitchell's Speaker Directivity thread (http://www.thegearpage.net/board/showthread.php?t=470956&highlight=directivity). Lotta fireworks, lotta science. I have Beam Blockers and they seem to help, but someday I'm going to have to make a Mitchell Foam Donut and A/B the systems. Anyhoo...get a coffee and make sure you have some time... :beer

--Ray

[Dave Orban]

I've used them in my Chieftain for years. Helps a great deal, IMO...

[mojotele]

Madison...Man that looks like a nice place to sit and play! Love it! ... and I want that armless chair!

[Tele Wacker]

This is one gimmick I have never tried.

[8len8]

They work ok for me, but a good alternative is painters tape. Just put an X of tape on the grill in front of the speakers. Has a similar affect.

[walterw]

the gist of the "speaker directivity" (http://www.thegearpage.net/board/showthread.php?t=470956) uber-thread is that beam blockers don't actually work, because the beam doesn't come from the center!

the beam is created by the whole speaker, but only when you're directly in front, so that it's centered on you. in fact, the bigger the speaker, the more it beams, proving that the effect isn't caused by the dust cover.

[schwa]

Not to de-rail the thread, but I had some speakers that were beaming and I made up some of the donuts.

What actually cured the issue was a change of speakers.

[epluribus]

One other rocket science note...when I did mine, I started with a couple of dead CD's and some gaffer's tape. I'd first suggest trying a bunch of stuff out that way before buying something. Personally, I don't think the difference is especially huge. The amp I put mine on sounds awesome in bigger rooms...the place I had it earlier was just too small for 130 watts. Like I say, I still gotta try a donut...

--Ray

[WhoJamFan]

I like the Beam Blockers on a 412 with 80s Celestion gt12-75s and it took the icepicky grind right out of them. I used to have to fight the soundguy about where to place the mic because the center was so bright. Ever since I put the Beam Blockers in, the cab no longer grinds, is easy to mic, and easy to hear on stage.

I don't wanna tape or glue anything to my grill cloth, can't stand the way it looks, so I guess that leaves me out of all the other suggested options. The Beam Blockers don't mess with the grill, and are invisible once installed. There may be more "efficient" things out there, but by no means are these things snake oil. The cabinet absolutely killed before, and now it's even more useable. Not too shabby for less than half the price of a comparable quality new speaker, much less four.

[Cirrus]

the gist of the "speaker directivity" (http://www.thegearpage.net/board/showthread.php?t=470956) uber-thread is that beam blockers don't actually work, because the beam doesn't come from the center!


This seems to be the party line at TGP and while the whole foam donut thing sounds like a very elegant solution, to claim that beam blockers don't work isn't very fair. In my experience they work as advertised, giving you a more consistant sound at various angles from the front of the cab.

Ultimately I decided I prefer being able to change how much sound is going into the crowd by angling the cab sideways, so I don't use beam blockers any more.

[tedzepplin]

The "foam" fans enjoy posting that the beam blockers don't work. They work for me. They lessen the beam while retaining a bright, lively sound. I really don't care that someone tells us that highs come from the entire speaker and that beams cannot possibly work. Sorry, they work.

For me, The foam works too - but with different results. The foam makes the amp sound like it is turned sideways. Which is what it's supposed to do - so it's working. It's just that I don't like having the dull sound it gives. I can turn my amp sideways or throw a blanket over it if I want that. But some guitarists like that sound.

[Birddog]

I used them in my Peavey Valveking 212 for a few years. I like them, particularly for gigging.

I don't have them installed on my Fender Twin that I'm currently using, but I probably should.

[Fred Farkus]

One other rocket science note...when I did mine, I started with a couple of dead CD's and some gaffer's tape. I'd first suggest trying a bunch of stuff out that way before buying something. Personally, I don't think the difference is especially huge. The amp I put mine on sounds awesome in bigger rooms...the place I had it earlier was just too small for 130 watts. Like I say, I still gotta try a donut...

--Ray

I tried the CDs and the foam donuts and didn't really like either one. In the end I think I was fixing something that wasn't really broken in the first place. To my ears, both techniques just rolled some highs off without really affecting the directivity very much. The 4x12 was still fairly "beamy" with these changes, just more rolled off overall- but still beamy. Yeah, 4x12s are beamy, grass is green, the sky is blue, etc...

[epluribus]

Yup, I'm 'fraid on this one that after all the science is in, the ears win all. S'pose that makes sense, actually. :)

--Ray

[Fred Farkus]

I was really hoping it would work. In the end, I think hanging a terrycloth towel over the cabinet worked best for providing a gentle high freq roll off (which still did nothing for directivity).

[solitaire]

The "foam" fans enjoy posting that the beam blockers don't work. They work for me. They lessen the beam while retaining a bright, lively sound. I really don't care that someone tells us that highs come from the entire speaker and that beams cannot possibly work. Sorry, they work.

For me, The foam works too - but with different results. The foam makes the amp sound like it is turned sideways. Which is what it's supposed to do - so it's working. It's just that I don't like having the dull sound it gives. I can turn my amp sideways or throw a blanket over it if I want that. But some guitarists like that sound.
Foam fans don't claim the beam blockers don't work, but they don't operate in accordance to how Ted Weber describes them + they have plenty of backdraws, such as phasing and filtering going on.

You just have to adjust the diameter of the hole in the donut to let through the amount of highend you want, so I think you may have grabbed this stick at the wrong end.

Enjoy your playing!

[neastguy]

I'm really surprised that the webers didn't work for so many of you.. I notice a big diff. with beaminess and cutting the highs down... have you stood about 20 feet in front of your amp? maybe if your just standing over your amp you can't tell as well.. just and idea..

[solitaire]

I'm really surprised that the webers didn't work for so many of you.. I notice a big diff. with beaminess and cutting the highs down... have you stood about 20 feet in front of your amp? maybe if your just standing over your amp you can't tell as well.. just and idea..There are obviously various sizes of the BBs and speakers can be brighter/ beamier by nature, so the BBs do filter off some highend. But it doesn't go after the nasty frequencies as mercylessly as for instance the artificial source method do. The BBs mainly absorb highend to a certain degree, but that's more arbitary yet with some gentle touch.

[GenoBluzGtr]

I use them on a Tweed Bassman (on all four speakers). I notice a difference at first. But I have found over the years, that the most affect they have is when you mic the amp. So perhaps, "up close and personal", they have a noticeable affect, however, when just using the amp, unmic'd, to amplify a room, it's less noticeable?

Re-iterate... when I mic my amp, big difference in the sound through the PA. When I don't mic it, not so much a difference to the overall sound.

[Dave_C]

I have always suspected that feeling the need for these devices was a sign that one just has the wrong speaker for their application. I seem to have gravitated to speakers which don't bother me at all when standing on axis. That all said, I find that I really dig the effect of the EC Collins grillcloth.

[tedzepplin]

...they don't operate in accordance to how Ted Weber describes them....

Is this the Weber description you are referring to? Are you saying that the Beam Blockers don't diffuse the high frequencies evenly in all directions?
http://www.webervst.com/blocker.html

"The Beam Blocker is a simple device that is installed between the speaker and the baffle. The dome shaped diffuser prevents point-source high frequencies from beaming directly out of the cabinet to create that ice pick sound. Instead, they are diffused evenly in all directions to blend with the lower frequencies which tend to radiate in a wider pattern. The Beam Blocker allows you to make use of speakers that have a tendency to be beamy, harsh, or generally unusable due to their extreme high frequency response. The idea of using a diffuser is not new. Many performers including SRV were known to have applied a patch of duct tape on the grill cloth directly inline with the center of the speaker to block the beaminess. The Beam Blocker performs that same function while diffusing the high frequencies evenly in all directions."

[WhoJamFan]

Just coming off an interesting week of touring and had a golden opportunity to listen to my 412 cab as the headliners we brought out from England used them. The venue was less than ideal and normally would have been much more of a nightmare, but the sound was very good, even, and consistant. I walked all around the cab and the audience, I found the sound never got harsh, or really changed when I moved around. I noticed when I was playing, I could hear the sound evenly as I used my wireless to go up to the tables.

I did not hear the same results with the other guitarists speaker cabinet.

[ultra]

I have used them for years and like what they do.

[Stu Blue]

Is this the Weber description you are referring to? Are you saying that the Beam Blockers don't diffuse the high frequencies evenly in all directions?
http://www.webervst.com/blocker.html

"The Beam Blocker is a simple device that is installed between the speaker and the baffle. The dome shaped diffuser prevents point-source high frequencies from beaming directly out of the cabinet to create that ice pick sound. Instead, they are diffused evenly in all directions to blend with the lower frequencies which tend to radiate in a wider pattern. The Beam Blocker allows you to make use of speakers that have a tendency to be beamy, harsh, or generally unusable due to their extreme high frequency response. The idea of using a diffuser is not new. Many performers including SRV were known to have applied a patch of duct tape on the grill cloth directly inline with the center of the speaker to block the beaminess. The Beam Blocker performs that same function while diffusing the high frequencies evenly in all directions."

There is no "point source" of the treble beam... Weber clearly doesn't understand how speakers work... in fact his beam blockers actually make the directivity measurably worse as the sound waves work around them. Reducing the total treble output is not the same thing as changing the directivity.....

Science is science... be careful or you'll wind up in magic mojo land. You ( and many others) fail to distinguish between overall tone and directivity. Anything you put in front of a speaker (including the cloth) will change the tone thru various phase cancellations... but that doesn't change the directivity of the speaker... the shorter frequencies will still appear to be louder in a narrow beam as you move across the axis. All frequencies are radiated by all parts of the cone.... as you move off axis, there is a different distance from one edge of the cone compared to the other so the same frequencies arrive at different times (out of phase) and cancel each other out... so you get less treble off axis.

EDIT Just to be clear, in reality, the treble beam comes from the edge. All frequencies shorter than the diameter of the cone will "beam".

[semi-hollowbody]

Smoke and mirrors, dudes - check out Jay Mitchell's foam donuts instead.
THIS!!
I had beam blockers on my drri, clasic 30, and my HRDX...they improved the sound tremendously...no more ice pick in my face, I could walk around the amp, lower or raise the amp, and the tone remained the same...sounded great...

but then I read all the facts and saw all the pie charts and bar graphs explaining how the beam blockers are crap and dont work, so I removed them and burned them...I no longer am duped by these piles of crap, but man I sure do miss the great tone I was getting with them...:(



Weber clearly doesn't understand how speakers work...

I know...no wonder EVERYONE HATES weber speakers...;)whenever I play through my DRRI (upgraded with a weber) despite the fact I LOVE how it sounds compared to the stock jensen it had, I remind myself that scientificly it sounds like shit...so I dont let my ears decieve me...;)



sorry for al the sarcasm...
weber dont know speakers...
Fender dont know amps...
lol...whats next, boss dont know pedals...

[Stu Blue]

THIS!!
I had beam blockers on my drri, clasic 30, and my HRDX...they improved the sound tremendously...no more ice pick in my face, I could walk around the amp, lower or raise the amp, and the tone remained the same...sounded great...

but then I read all the facts and saw all the pie charts and bar graphs explaining how the beam blockers are crap and dont work, so I removed them and burned them...I no longer am duped by these piles of crap, but man I sure do miss the great tone I was getting with them...:(


Yes indeed. Life is so perfect in magic mojo land. All that money you spent gave you a much better tone than us dumb scientific sheep. Of course you can be sure no-one exploited your ignorance to make a fast buck out of you......:sarcasm

[tedzepplin]

Science is science... be careful
Have you tried using the Beam Blockers? Have you compared them side by side with the foam? I mean actually compare them - not just on paper.

[stratotastic]

It would really be nice for someone to do some sound testing and post it. For example, have mics in various spots around a room then use the speaker bare, with beam blockers, and with donuts, and compare the results. Seems like it wouldn't be super difficult to do if you had this stuff already on hand and the means to do it. Not sure why it's even worth discussing otherwise as a bunch of guys giving opinions like "I think it sounds good" or "I don't hear a difference" really doesn't mean anything. :dunno

[Stu Blue]

People, can you all please take it on board that changing the tone of a speaker by placing anything in front of it, does nothing to change the directivity of the speaker, which is solely governed purely by the size of the cone, with all frequencies shorter than the diameter becoming more beamy. All 12 inch speakers beam equally, you just notice it more on bright speakers.

Jay Mitchell's "doughnut" will even out the directivity by reducing the on-axis treble quite noticably... probably too much for some (like me). It's the only thing available that honestly changes the directivity of a speaker (and he gave the design to us for free so god only knows why people want to argue about it).

[rburkard]

Using them requires you to be very careful with your mic placement. If someone angles the mic too close to the center of the speaker you will be in for a great surprise. Your tone will suck bad time. I had my bad experience with them already.
Rene

[dspellman]

This seems to be the party line at TGP and while the whole foam donut thing sounds like a very elegant solution, to claim that beam blockers don't work isn't very fair. In my experience they work as advertised, giving you a more consistant sound at various angles from the front of the cab.

Walterw's bang on; the beaming doesn't really come from the center of the speaker. The physics are the physics.

For anyone that's interested, there's a formula that will predict at what frequency dispersion will begin narrowing significantly, and on a 12" speaker that's gonna start happening around 1300Hz. The larger the speaker, the lower the frequency at which beaming begins.

Beam blockers work, sort of. They've been everything from X's of duct tape to old CDs over the speakers to things like the Weber that you pay for to cabinets like this THD that have blockers built in:

http://i18.photobucket.com/albums/b149/dspellman/Picture2-10.png

The issue is not whether they work, but whether there's a better solution. Turns out there ARE better solutions, and one was designed by an audio engineer (the rest of these beam blockers are just manufactured copies of the old "X" of duct tape, essentially). Beam blockers as we know them do strange and unwonderful things to the overall frequency response. The foam donuts work. Period. Without screwing with the sound overall. I will guarantee that anyone extolling the virtues of one of the various non-foam-donut beam blockers has never A/B'd the two. Though now I'm betting we'll get a few posters who will claim otherwise <G>. The real problem is that (far as I'm aware) you simply can't buy the foam donuts anywhere, while you can try the various beam blockers (both production and kludges) easily and inexpensively.

[scolfax]

I don't know anything about foam doughnuts but I put a Weber beam blocker in my Hot Rod Deluxe and it tamed the icepick highs and didn't cost a ton. Was not "strange and unwonderful" in my experience.

[billstets]

I used to have beam blockers and dumped them long before the Jay Mitchell thread surfaced. They may have tamed the highs a little bit, but they also introduced this weird almost muddy sound, like the notes were smeared. I believe this is the phase issue that has been discussed. I will never go back to them.

[tedzepplin]

I will guarantee that anyone extolling the virtues of one of the various non-foam-donut beam blockers has never A/B'd the two. Though now I'm betting we'll get a few posters who will claim otherwise <G>.

I've tried Beam Blockers and Foam. Has anyone else tried both?

[tedzepplin]

(and he gave the design to us for free so god only knows why people want to argue about it).

But have you ever tried Beam Blockers? Did it lessen the Beam for you?

[tele_jas]

I used them in one of my Dr. Z amps a few years ago.. I got them to disperse the "beam" from killing the audience (and sound man). When I got them, they did the job GREAT! The Sound man even said "you can turn up if you want"!?!?... But they increased my stage volume significantly, and not just for me - my whole band was now asking me to turn down. I was far stage right and the other guitarist, far stage left, was asking me to turn down.

I ended up taking out the BB's and started using a plexi-glass shield and have never looked back.

[walterw]

Geometrically, the beam blocker is a dome shape aimed inward toward the center of a cone. If the sound waves emanating from the surface of the cone travel in a direction perpendicular to the plane of the cone, the vector will intercept the BB dome wiithin a range of acute angles depending on where you measure the vector. Seems to me the sound waves short enough to be affected by the BB (highs) would reflect away and outward. Some would miss and travel past it, and only a small percentage of the waves coming off the dust cap would interact as that is an outward facing domed surface. Seems like this actually would "mix up" and disperse the sound waves pretty well, which is consistent with Ted Weber's claim. I can also see how it could introduce unusual phasing effects.

I have not tried them myself. I did try the old CD and did not notice a tremendous change. I think having the domed surface is important.
read some of the pertinent thread;

the treble doesn't emanate "perpendicular" from a given spot, it emanates in all directions from the whole speaker.

the beam is created by the whole speaker, including the part that isn't blocked by the thing in the middle, but only when all of the speaker is the same distance from your ears, i.e., when you're directly in front of it.

the blockers cause some phase smearing stuff that can reduce the treble a bit.

[tedzepplin]

It would really be nice for someone to do some sound testing and post it. For example, have mics in various spots around a room then use the speaker bare, with beam blockers, and with donuts, and compare the results. Seems like it wouldn't be super difficult to do if you had this stuff already on hand and the means to do it. Not sure why it's even worth discussing otherwise as a bunch of guys giving opinions like "I think it sounds good" or "I don't hear a difference" really doesn't mean anything. :dunno
Ofy8Jz-HxBo

[Prairie Dawg]

Ooh. I now have a headache. That was painful.

[pula58]

great comparison demo tedzepplin!

[rhythmrocker]

Ofy8Jz-HxBo

Too bad it wasn't recorded in 3D and
too bad we weren't there to hear it live and
too bad we are only hearing what the mic picked up, albeit badly,

I thought you had more sense than this man, comeon.

I used to use Weber beam blockers - now foam baby.

[tedzepplin]

u_BaO7Mg3oQ

[BEACHBUM]

I make my own for $2 each. Aluminum from Home Depot and speaker dust coil covers from Parts Express. As many as I use I couldn't afford them from Weber.

I tried what SRV used to do and it works. All you need is some duct tape and the insensitivity to not care what it looks like.

[Norjef]

Used to use BeamBlockers - soundmen way downwind still whined about "death-ray".
Then I tried foam on same cabs, amps (and bands) - no more whinin - really....and cheap !! Simply makes off and on axis tone more consistent and predictable.

[WhoJamFan]

Science? Like Solid state amps sound better than tubes, and replacing everything on your guitar with brass will give you way more tone and sustain, and up until recently, that wireless units sound better than cables? You want to talk about how things can't be so because of science, well, I'd rather just ACTUALLY play things live with a band in the ever changing situation of different venues sonic properties and make a decision based on real world experience.

I find something that works for me and I share that on a public forum and all of the sudden I believe in fairies and convince myself I'm hearing something I'm not?-wow-like I'm gonna go hang myself now-haha. So all of us who use them are wrong?

Horsefeathers!

The issue isn't are the claims scientifically provable verbatim and to your interpretation of them, the issue and topic is simply do they or don't they make an ice pick speaker situation diminish to the point of making it worth it to employ them. "Does anybody use them?" The answer to that has been yes, although others have found different means to achieve their desired result, or disliked the byproduct of it to remove them. This was a thread about folks who have actually tried them and use them, not a slam session on Weber and the people who use their products. If you have indeed tried them, then you have an opinion, if you have not tried them, than your answer has no value in a discussion that asks if anybody is using them. If you have a problem with what a product is advertized to do, and the scientific improbabilities of it, than start your own thread about that and go to town. Everytime a thread about these comes up it's always the reference to the guy with the foam discs and the rocket scientists going ballistic over the nuts and bolts of it, but what you rarely get is some actual information about how it sounds and does it work.

Getting nit picky is really kind of fruitless in an industry where things are commonly called something they are actually not. This is widely accepted-like Tremolo on a guitar is actually a manual vibrato unit, and a treble bleed circuit in a Tele is actually a treble bypass, and the coil tap was actually a single coil that had lead wires that allowed you to "tap" into the pickup in various places to get more sounds out of it, not a wire that grounded out 1 coil of a humbucker to give it a single coil sound. I could go on but I think we get the picture here.

So, when Ted Weber came out with the Beam Blocker, is was something for people who had that beam of death speaker to use to combat the situation. I don't think he was trying claim he had a magical device that defies the laws of physics and science. He probably looked at an old Jennings VOXAC30 combo and saw the wood come down in front of the cone like a BB does, and went from there. Who knows, but to say Ted Weber didn't know anything about speakers is about as ignorant as saying Vox didn't know anything about electric guitar amplifiers.

While these are not for everybody, plenty of people like them and use them. I for one, am happy with how I sound all over the stage, through the monitors and mains, and when it gets recorded live by someone in the audience. I just played an outdoor hotrod and chopper show a few hours ago and was happy with my sound. Didn't need a slide rule, table of elements, or a persniketty professor to make sure all my electrons were lined up in a row.

Great video TEDZEPPELIN, now folks have something signifigantly to go on when dealing with the death beam issue.

[hywelg]

but what you rarely get is some actual information about how it sounds and does it work.



Jay Mitchell donuts do exactly what he says and proved they do. I tried them and they work. They are very cheap to implement.

What it boils down to is whether, when you eq your amp on stage you stand in the beam and like that sound. IF you are used to standing above and/or off to the side and you eq it standing at that position then the beam may well be a problem for the audience.

Tedzepelins test is not representative of the situation outlined above, where the guitarist is above or off to the side of the beam. His video does indicate a loss of highs, which is exactly what Jay Mitchell says will happen, the foam has killed the beam. Indeed you get a small drop off of high end off axis (again Jay Mitchell states this will happen) as well, but you do know that it is consistent over the whole spread of the sound so you can re-eq the amp standing wherever you like and know its what everyone else is hearing also. To my ears both the cd and the beam blocker had an unwelcome effect on the lows. Duct tape was marginally better, ¾" foam was too much ½" foam was the best of the bunch. Of course what we can't hear is how horrible the actual live sound was on axis. It might have been OK but I have been to enough gigs to know that when its horrible you have to move somewhere else. The Peter Greier Video is a better illustration of the effect, though I would like to have heard what the effect was like stood above the amp like the player.

Now I haven't a/b'd these foam donuts with a Weber BB, but I have talked to other guitarists (pros with way better ears then me) who tried WBB's and didn't like the effects. I am simply relating my experience with the JM Donuts, which I have in all my speaker cabs and have put into some of my mates cabs as well.

So, all the people who have been posting about the donuts and have been accused of derailing the thread, you are right to do so. They are telling those minded to buy Weber beam blockers that there is a better, cheaper way of reducing the beam effect. Perfectly legitimate IMO.

[tedzepplin]

Now I haven't a/b'd these foam donuts with a Weber BB....

That's part of the problem. Some people are overly confident that something they have never tried cannot work.

[Jef Bardsley]

That's part of the problem. Some people are overly confident that something they have never tried cannot work.
:rimshot


Despite all the cautionary tales of old, no one has ever sailed off the edge of the world.

[Rockerduck]

duct tape still works for me. I don't care what other musicians think. I care what the audience thinks, and the guy paying me. Beam Blockers work, cd's work, donuts work. To be clear, I use the amps provided me at shows, and monitors. I carry duct tape and cut a piece off and put it there myself. 40 yrs. and still works.

[Stu Blue]

That's part of the problem. Some people are overly confident that something they have never tried cannot work.

Science is science... be careful or you'll wind up in magic mojo land. You ( and many others) fail to distinguish between overall tone and directivity. Anything you put in front of a speaker (including the cloth) will change the tone thru various phase cancellations... but that doesn't change the directivity of the speaker... the shorter frequencies will still appear to be louder in a narrow beam as you move across the axis. All frequencies are radiated by all part of the cone.... as you move off axis, there is a different distance from one edge of the cone compared to the other so the same frequencies arrive at different times (out of phase) and cancel each other out... so you get less treble off axis.

EDIT: Jay Mitchells' doughnut does cut the treble, but it reduces the treble from the edge and the hole in the centre acts as a virtual small speaker speading the higher frequencies more evenly. It is the ONLY device available that also changes the DIRECTIVITY of the speaker to a more even spread... everything else merely cuts the top which fools many people into believing the directivity has changed when it hasn't. The frequency that beams is entirely determined by size of the cone... all 12 inch speakers beam equally, they just vary in tone NO MATTER WHAT YOU THINK YOU HEAR. This can/has been measured... so don't argue about it... learn something instead.

[oldman22]

In my Marshall 1936 they rattled. So I returned it.