Horn Dampening--811B

[Gary L]

In my quest for the optimum performance from my speakers I keep hearing from many that the first thing is to dampen the 811B horns.
I don't hear any ringing but I do listen in the nearfield and have some time to mess around.

Lots of info but what I need to know is where do I concentrate the dampening on the horns? Does it go on the back side behind the baffel, on the front side part that protrudes out, both? What is best.
Also I have heard alot about what to use but would like some advice from those who have found what works and is relatively easy to put on/get off.
Do I mix some tar type concoction, by sticky backed material, spray undercoating or what?
I do not wish to destroy my horns by cutting fins, nor do I want to destroy the looks of them by gooping up the exterior visible portion.
Don't know if others feel this way but at times I like to remove the grills and watch the speakers work while I listen, usually when I am getting loud, just seems to add to the pleasure.

Any help on this subject.

Thank you

Gary

[doclamb]

Gary, I recently refurbished a pair of 19's. To dampen the 811's I used Evamastic, a sound vibration dampening material that comes in 32" x 54" sheets and is .079" thick. I believe it's used to reduce vibration for mechanical ducts. One sheet covers both horns. I purchased the material through McMaster-Carr for $22/sheet shipped. One side of the material sticks to the metal on the horn well enough but it seemed that if you wanted to remove it at a later date, it wouldn't destroy the horn. The material was easy to cut with a utility knife to the shape of the 811 and I applied the mastic to all external surfaces of the horn except where the flange meets the cabinet. There I used double sided weather tape. The results were that when I tapped on the horns prior to mastic it would ring like a bell. After application there was a dull thud and it sounded close to wood. It smoothed out the horn and was definitely worth the $22 and 2 hours of time.

[edgewound]

Another material you can use is Dynamat sheet. It's a sticky-back asphalt sheet loaded with mica for vibration damping. Clean all the surfaces with rubbing alcohol, then cover the inside bells of the outer horn, and the inner flare that lives in the cabinet. It focuses the upper mids and highs from the fatiguing ring that happens at around 1000hz.

There's other brands of the sound deadening sheet, too...you can find a few different types at Parts Express:

http://www.partsexpress.com/webpage.cfm?webpage_id=3&SO=2&&DID=7&CATID=35&ObjectGroup_ID=37

[Mr. Widget]

In my quest for the optimum performance from my speakers I keep hearing from many that the first thing is to dampen the 811B horns.
I don't hear any ringing but I do listen in the nearfield and have some time to mess around.
That's because you listen to your music so loudly that your ears are already ringing!:rotfl:

Sorry... I couldn't help myself. Many times there are "problems" with speakers that we filter out with our onboard computers. After fixing the problem your listening experience should be a bit more open and relaxed... the sound will be slightly more true. The improvement will be subtle but well worth it.


Widget

[Gary L]

Thanks for the links and advice on this. Do either of you have photos of the finished horn so I can see the resulting look?

I have been considering useing the goo they sell for dipping plier handels in to renew the insulation but I am not quite sure of what properties the dampening material needs to have.
A friend used Great Stuff, the insulation in a can for filling cracks and crevices. It looks like $hit but his horns do Thud now instead of ring and sound a bit less shrill then mine.
Some have even mentioned that Rhino Coating stuff they spray as bed liner in PU trucks. I could get this done easy enough and it would look just fine if you think that would work.


That's because you listen to your music so loudly that your ears are already ringing!
Thanks Widget but you might be right!!

Gary

[edgewound]

Hey Gary...
I don't have any pics of a dampened Altec horn, but if you do it like I said in the previous post, you won't see it from the front. You said that you want something reversible and this solution is just that. Once you start spraying stuff on, it's a MUCH bigger chore to remove it if you choose to do so.

Rhino Lining, etc, might work fine, but it's a bitch to cut and peel off, and is for the most part permanent....and pretty expensive. You can get the same type of bedlining material in a spray can at the auto parts store now...if that's what you want to do.

I'd go with the Dynamat type stuff.

[Gary L]

Think you are right Edgewound. I am sitting here right now with some brown paper cutting and fitting the pieces for patterns. Whats behind the baffle doesn't matter how it looks but up front I really want to keep them looking right.

I am a bit of a Perfucktionist with this stuff so it takes me a while to get R done.

Should have just built wood horns while I was building the cabs but thats yet another future project.

Gary

[doclamb]

Gary before I decided to use mastic I did my due diligence on Altec Lansing unofficial site. They have more information if you look up past threads, however most of the cures are non-reversible. Sorry no pictures, but with the mastic in place it's really not noticeable and the dam horns "thunk" like wood. In addition I purchased new foam surrounds that go around the cabinet face at the outer edge of the horn. I purchased them from a nice couple in No. Carolina who do a remarkable job of replicating them [email protected]. for anyone who's interested. These look just like the originals and are highly recommended. $50 shipped for two of them. With the foam inserts in place all you can see is the front of the horn. I don't know about sound improvement although I've read here and at other sites that there are those who have notice a slight improvement. Good luck, Rob

[subwoof]

Back in the 70's I worked afterschool at a dealership that had an outside contractor do undercoating on the jeeps and cargo vans they sold.

The super-tough black plastic they sprayed on the bottom of door panels to prevent small stones from chipping the paint worked like a charm on a pile of 811B's we snagged from a local auditorium's remodeling project.

It was better than the flakey stuff that always fell off the big multicells and it really killed that ring on the horns.

We timed the ring on one horn after it was struck while hanging from a fishing line. 30+ seconds of ring sure made us decide to go to JBL...esp after we had to buy those expensive TEN WATT diaphrams over and over and over...

:cheers:

sub

[Baron030]

Hi Gary L
I don't think the pliers dipping goop would be very effective.
And you said it yourself, the "Great Stuff" looks like $hit.
I'd recommend that you go with a "Constrained-layer" damping material like Dynamat Xtreme. The thin aluminum "Constraining layer" dramatically increases the effectiveness of the damping material. I used this stuff on my car and the results are pretty impressive. So, I know that it will work well on the 811B.
Baron030 :)

[Zilch]

Read what Jean (B&KMan) says here:

http://audioheritage.org/vbulletin/showthread.php?p=90544#post90544

[Storm]

I have a pair of 846U speakers and where the horns are mounted there is wood on the sides and top and bottom, along with foam (not insulation). The foam fits on the sides and top and bottom of the horn. Is this an ample horn dampering or do I need to get inside the cabinet and put stuff directly on top and bottom of the horn?

Thanks.

:p

[Don McRitchie]

No, that foam has negligible impact on damping the horn. It is intended to address diffraction problems caused by HF reflections from the sidewalls of the enclosure that extend beyond the horn mouth.

[Storm]

No, that foam has negligible impact on damping the horn. It is intended to address diffraction problems caused by HF reflections from the sidewalls of the enclosure that extend beyond the horn mouth.

OK...so, Don - what do I use?

Does the Model 19 fix that problem of the horn? Why didnt they address the diffraction on the 19's with foam like they did on the 846u's?

Can you hear the "ring" in the 19's or is that non-existent?

In your opinion, should I sell the 846's and get a pair of 19's?

Thanks.

-Storm

[Gary L]

Hi Storm. I think the ring is inherent in all 811B horns no matter what cabinet they are in. I am not familiar with the 511 horn but suspect it too has the ring.
When I had my original 19s they came with foam inserts around the face and bell of the horns. Best way to describe it, just about the consistency of the foam used on temperpedic beds. It disintegrated after many years and turned to goo.
I have 19 clones now so the inserts made for real 19s won't work for me or for Valencia owners.
I am going to order the dynamat stuff and just consider it another project along the path of audio bliss.
I did want to get away easy and spray them with some form of gunk but think you all here have changed my mind on this approach. I do want them to look good so I cut templates and will make the mat fit in all the right places and out of sight.

Thanks for all the great info.
Off to read what Zilch suggested now.

Gary

[Storm]

A light bulb just switched on in my head!

Ah, I see now...

So, there is just a very slight difference between the Val's, Flameco's, and the 846's in comparison to the Model 19's.

I thought there for a moment that I should grab a pair of 19's and replace my 846's, but if there is still a "ring" in the horn, then I won't bother.

For those who know - does the Model 19 crossover help alleviate the ring? Some have said that the 19's are smoother in sound and not as harsh. But, to be honest - I love that "Live" sound and sometimes the "ring" is too much, but most likely that is from the recording.

As someone on this board said, the source is 90% and speakers are 10%, so if you have a bad recording, you will notice. Likewise, the horns that most people dont like - which is the jazz and the classical genre of fans - the highs can be harsh. But, for the rock and roll and classic rock - these speakers kick butt!

I was scanning the altec unoffical site today and did not realize that James Lansing created Altec. And I had no idea that in 1949 - James Lansing committed suicide. Wow, what things we learn whilst parousing the vast internet.

Anyone else think I should replace my Altec 846's with the Model 19's? Any opinions are greatly appreciated.

Hurry...there is a pair in CA right now on eBay. I could take a day trip and go pick them up.

I still want to hear a pair of L200's or L300's. If anyone on this board is in Arizona, I would love to come take a listen.

Thanks a bunch.

Looking forward to continuing this "lively" thread.

:applaud:

[Mr. Widget]

I thought there for a moment that I should grab a pair of 19's and replace my 846's, but if there is still a "ring" in the horn, then I won't bother.

For those who know - does the Model 19 crossover help alleviate the ring? In my opinion the difference between the earlier Altecs and the Model 19 isn't trivial. The EQ crossover and box tuning are a big help.

Can the crossover help the ring? No way... there is no way an active or passive filter can fix the problem... it is a mechanical resonance... it needs to be physically dampened.



I love that "Live" sound and sometimes the "ring" is too much, but most likely that is from the recording.:blink:


Widget

[Storm]

So, should I get 19's and sell my 846's?

Thanks.

-Storm

[Zilch]

.
I use Altec 846u's and will NEVER sell them - they are the BEST!

[Mr. Widget]

So, should I get 19's and sell my 846's?Not if YOU like them...

Between the two, I'd go with the 19s... if I had a broader selection, and I do... I'd look elsewhere entirely.


Widget

[Storm]

Agreed, but while reading Model 19 posts, I am leaning towards them...

I am just trying to get a second opinion on how much "smoother" the sound is than on the 846 series.

I know what I said...I am not going to sell them to pay for drugs, but if Model 19's are better, then I want to know so I can find a pair and buy them.

Thanks for stating the obvious, Zilch.

;)

[mbask]

I know what I said...I am not going to sell them to pay for drugs,

Thanks for stating the obvious, Zilch.

;)[/quote]

HA HA HA HA:rotfl:
Storm.. your are a delight :D
the 19s cost less to manufacture (all things considered )
the "ring" ? ..employ EQ unit of decent quality and adjust 4K until satisfied
OR: clamp two pieces of ridgid type styrofoam at the throat of the horn, inside the cabinet..then you will be "lord of the ring":)

any rings?:p

[Storm]

I will find an Equalizer and do that.

My back of the cabinets are sealed shut, so removing the horns from the front and damping them would be quite difficult.

Now I am on the search for an equalizer....any suggestions??

Yea, once I get an EQ I will be ultimately satisfied and will never consider owning any other speakers...

Yes, I will stop posting "should I...could I...will I" questions regarding the Model 19s.

I greatly appreciate everyone on this board, you guys are awesome!

:applaud:

[mbask]

there was one JBL/Urei EQ on the LA craigslist a week ago i don't remember the model, I think it's been nabbed though

[Mr. Widget]

the "ring" ? ..employ EQ unit of decent quality and adjust 4K until satisfied...Isn't that like painting over the dirt instead of doing the cleaning? Not to mention if you do use a notch filter and cut out the ring you will also be losing a portion of the overtones of many musical instruments.


Widget

[Zilch]

Can the crossover help the ring? No way... there is no way an active or passive filter can fix the problem... it is a mechanical resonance... it needs to be physically dampened."Filter" presumably incudes equalizer.

So, we have determined the "ring" is at 4 kHz, have we?

I should just shut up, rather than sayin' stuff folks don't want to hear here.

Slide over, Giskard, buddy.... :)

[edgewound]

"Filter" presumably incudes equalizer.

So, we have determined the "ring" is at 4 kHz, have we?

I should just shut up, rather than sayin' stuff folks don't want to hear here.

Slide over, Giskard, buddy.... :)

I think one would find that if one removes the horn from the enclosure and flicks the bell with a finger or screw driver....whatever...one will find that the ring is at about 1KHz when compared to a sine wave from a sweep generator.

An EQ with enough applied cut at 4KHz will, as paraphrasing Mr. Widget..."screw things up". You'll simply take out too much music.

[mbask]

Do we want the ring of a trumpet?
yes "enough" can be too much. as i stated "adjust until satisfied"


Widget.. does "cleaning" mean that dirt goes to another planet?
Your analogy seems at odds with your apparent technical command.

[Storm]

:rockon2:


RIGHT ON!


FUNNY STUFF, MBASK !
:nutz:

[edgewound]

Do we want the ring of a trumpet?


If it's in the interest of accurately reproducing the recording...yes, I do.:yes:

[mbask]

I think one would find that if one removes the horn from the enclosure and flicks the bell with a finger or screw driver....whatever...one will find that the ring is at about 1KHz when compared to a sine wave from a sweep generator.

An EQ with enough applied cut at 4KHz will, as paraphrasing Mr. Widget..."screw things up". You'll simply take out too much music.

I'm getting 3.6KHz horn fastened to the cabinet.
and if you listen to "Rush: Moving Pictures" 4k @ -6 seems to do it:)

[Mr. Widget]

Widget.. does "cleaning" mean that dirt goes to another planet?
Your analogy seems at odds with your apparent technical command.:blink:

Years ago for a summer job I had the opportunity to paint student rental housing... I was not paid to clean the cobwebs and pizza etc., just slapped the paint over it... the idea was that was good enough for the tenants.

The point is that bailing wire, duct tape, and chewing gum may get you home, but it isn't the same as fixing the problem. And then, I mentioned the unintended consequences of using the EQ as a Band-Aid...

...or did I miss something blindingly obvious? My wife complains that I can never find anything in the refrigerator.:blah:


Widget

[Mr. Widget]

...and if you listen to "Rush: Moving Pictures" 4k @ -6 seems to do it:)Oh! I was thinking you were using these things for playing music... go ahead and EQ away... and tame that annoying singer too while your at it!:applaud:


Widget

[Storm]

What are you talking about?

RUSH IS THE BEST DAMN BAND AROUND!

What do you listen to - pixie ballerina crap?

;)

[mbask]

Oh! I was thinking you were using these things for playing music... go ahead and EQ away... and tame that annoying singer too while your at it!:applaud:


Widget

He's also the Bass player, and keyboardist.:D

[Mr. Widget]

What are you talking about?

RUSH IS THE BEST DAMN BAND AROUND!

What do you listen to - pixie ballerina crap?

;)Thank God there are lesser bands...

BTW: I couldn't find anything by the Pixie Ballerinas.:(


Widget

[Storm]

I was only poking fun. Do you know how to laugh?

Try it sometime....

:)

[Steve Schell]

One way to damp an aluminum horn is to place several ziplock bags full of sand on top of it. This is fairly effective while making no change to the horn. Sandbags could be lashed to both top and bottom if needed, and behind the lips in front.

I have had great luck in damping aluminum turntable platters with a loaded vinyl sheet called Black Hole. It is available from Speaker City here:

http://speakercity.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=SC&Category_Code=damping

Although they refer to it as a dampening material, thankfully no moisture is involved :^). The self adhesive on this stuff is very aggressive, so I doubt if it could be pulled loose from the horn without lifting some paint.

[Tom Brennan]

I've damped 511 horns very nicely by pressing rolls of non-hardening modeling clay into the "lips", both top and bottom. I presume the same would work with 811s.

Cutting the vane welds and filling the kerfs with rubber also damps the horn, late model 511s came like that from the plant.

Note that the bolting of the horn to the baffle also damps it.

In any event I wonder if the driver produces enough energy to excite ringing or if we just imagine we can hear it, I suspect there's a big difference between striking the horn with a metal tool and running sound through it.

I now listen to a set of Heathkit AS-21s (9844s in furniture cabinets) and I decided to just leave the damned things alone and listen to them, no mods or tweaking. And I enjoy them very much.

[Mr. Widget]

I now listen to a set of Heathkit AS-21s (9844s in furniture cabinets) and I decided to just leave the damned things alone and listen to them, no mods or tweaking. And I enjoy them very much.That is probably the best advice I have seen on this forum in a very long time!:thmbsup:


Widget

[Storm]

Could it be just like all other tweeters and mids...that the engineers intended for the "ring" to be there. They were artists in their own right, so why wouldn't they want that "ring" to be evident?

Horns are in a league all their own, they can play by their own rules!

:)

[Gary L]

This has all come around and back to my original statement.
I don't hear any ringing at all from my horns that are bolted fast to the baffle. I just have some time to play around and an extra set of horns so I thought I would play.

One thing we have touched on and it does puzzle me. 511 and 811 horns have been around a long time and I would think if ALTEC thought there was a problem with ringing they would have addressed it. Could it be we are just armchair quarterbacking here?

For you Storm. I don't think you are going to be happy until you answer the 846 Vs 19 question with your own ears. Go find some 19s to listen to so you have the info in your head. I do like them better then 846s but thats my opinion. You need your own opinion on them.
To take a line from a song " Love the one your with "!
If you hear some 19s and like them better then I guess a divorce is in the making. There is not a thing wrong with 846s, I just think 19s sound a little nicer but you need to decide this for yourself.
I play all my music flat and with tone controls defeated, but again, thats my preference. NO ONE HERE CAN TELL ME HOW MY EARS HEAR!!!!!

Gary

[Zilch]

Could it be just like all other tweeters and mids...that the engineers intended for the "ring" to be there. They were artists in their own right, so why wouldn't they want that "ring" to be evident?
Take yer meds, Storm.

It's ignorant prattle you're posting here....

[Storm]

Yer? - what are ya from tha sauth (south)? ... even better, Berkley CA!

:p

Come'on Zilch - why do you have to chime in with your rude comments like that?

For your information, I am not babbling meaninglessly. I am only making a valid point that just like artists, these engineers could have purposely incorporated the "ring" into the horn.

I know, lets use your time machine and go back and ask them!

:banghead:

Leave everyone alone, please. Thank you.

:D

----------

I agree, we are over analyzing the horns. Just like any sports commentator over analyzes any great athlete.

We need to all just sit back and enjoy what we have and be grateful.

Gary - your'e right, if there was a "ringing" problem, I am sure Altec would have fixed it right away. And, I am listening to my 846's right now and I think we make ourselves hear what we want to hear. When I take the ringing out of my mind, I do not hear it.

Like I said before, I think the problem exists to those who want to make it exist and for those who listen to high pitched music like opera, classical, and jazz.

-----------------

[Zilch]

Come'on Zilch - why do you have to chime in with your rude comments like that?Because the underlying premise of this site is information, not fiction, and when you post a load of poo that stinks the place up, I'm gonna call you on it.

And you, with your avowed contempt for the science and technology of loudspeaker design, are certainly in NO position to be speculating as to the intent of the engineers accomplishing it.

There is a vast literature available for your perusal on the evolution of the art. Unfortunately, it largely comprises, uhmmm, "boring and stupid" graphs apparently well beyond your comprehension.


Ignorance is lack of knowledge. Stupidity is denial of reality in the presence of knowledge and wisdom.Allow me therefore to correct my earlier assertion:

It's STUPID prattle you're posting, is what....

[Storm]

Okay...so no one can have a casual argument on this site, it has to be about graphs, charts, tables, and information?

Is it past your comprehension that the best graph in the world is your own EARS?

If you don't like what I post, why bother responding to it...click that "x" and get off the page - simple.

:blah:

[edgewound]

Yer? - what are ya from tha sauth (south)? ... even better, Berkley CA!

:p

Come'on Zilch - why do you have to chime in with your rude comments like that?


Who's being rude? I think you bashed Widget, too.





For your information, I am not babbling meaninglessly. I am only making a valid point that just like artists, these engineers could have purposely incorporated the "ring" into the horn.

I know, lets use your time machine and go back and ask them!



Cutting the vane welds and filling the kerfs with rubber also damps the horn, late model 511s came like that from the plant.


I think Tom contributed a good post on that. No need for the time machine....it's called proof.



:banghead:

Leave everyone alone, please. Thank you.

:D


That's uncalled for, too. Zilch studies alot of this stuff, empirically.
----------



I agree, we are over analyzing the horns. Just like any sports commentator over analyzes any great athlete.


There isn't a hell of alot to analyze. This is subject is common knowledge among experienced users, and you're getting the knowledge for virtually free.

We need to all just sit back and enjoy what we have and be grateful.

See my preceeding comment. Most of us here are grateful for Lansing Heritage



Gary - your'e right, if there was a "ringing" problem, I am sure Altec would have fixed it right away. And, I am listening to my 846's right now and I think we make ourselves hear what we want to hear. When I take the ringing out of my mind, I do not hear it.

Like I said before, I think the problem exists to those who want to make it exist and for those who listen to high pitched music like opera, classical, and jazz.


With all due respect, and not intending to start, or fan, a flame war...that statement makes about as much sense as comparing the performance of a Ferrari Enzo to that of a Yugo and thinking that the difference is all in your head.

[grumpy]

Cordiality and tolerance are generally free.
Respect is earned.

-grumpy

[Zilch]

Is it past your comprehension that the best graph in the world is your own EARS?Minutes ago, you, yourself, identified the inherent shortcoming of that approach:


And, I am listening to my 846's right now and I think we make ourselves hear what we want to hear. When I take the ringing out of my mind, I do not hear it. Thus, only OBJECTIVE criteria can resolve these issues, and engineers dedicate themselves to that discipline.

Then, in summary,
Like I said before, I think the problem exists to those who want to make it exist and for those who listen to high pitched music like opera, classical, and jazz.Akin, somewhat, to being better able to imagine life-size performers with stacked L100's? Prattle.


Zilch----Get off your high horse. Storm was just speculating, kind'a thinking out loud to us.I'm genuinely sorry, Tom. While this is in "anything goes" DIY, the thread is a serious inquiry into a matter of interest to many readers coming here for reliable information such as you posted above.

In which context, there should be no harm in clearly identifying, in contrast, meritless pap as being exactly and only that.... :yes:

[Tom Brennan]

"While this is in "Anything goes" DIY, the thread is a serious inquiry into a matter of interest to many readers coming here for reliable information such as you posted above."


Which is one reason why, on second thought, I deleted my comment.

Regards

[moldyoldy]

Even with more than 8 categories to post in, there's still only 2 trains of thought;

A. Myth, Magic, and The Best of BS.

B. Science and Technology

Problem is, those in group A don't like their title, yet are either unwilling or unable to complete the homework required to competently participate in group B, and assume their magic can compensate for any shortcomings.

News Flash for group A; Magic only works when science ain't around (check your history books for proof). Spout some BS in the presence of science and be prepared to learn and be humbled, or get cut off at the knees.

[edgewound]

News Flash for group A; Magic only works when science ain't around (check your history books for proof). Spout some BS in the presence of science and be prepared to learn and be humbled, or get cut off at the knees.

While this may be true...it's still up to all of us to keep the place friendly and cordial....respectful.

Tho we do plummet into a little fun now and then.;) :duel:

[moldyoldy]

True on all counts, Edge.

Didn't mean to be smug, though there's something about smugness that seems to accompany 'knowing you're right', and having proof of it. Another human frailty.

I think the hardest part of qualifying for group B is the ability to admit to self that your latest project didn't turn out as well as you'd hoped, isn't the hottest thing on the block, and would embarrass you if your peers heard it. Once you've been-there-done-that, you can apply what you learned to the next one.

[Mr. Widget]

I think the hardest part of qualifying for group B is the ability to admit to self that your latest project didn't turn out as well as you'd hoped, isn't the hottest thing on the block, and would embarrass you if your peers heard it.You think?

Scientists do that regularly... look, "my experiment to prove X blew up, but I invented Y." Unfortunately it'll be a generation before anyone can figure out what to do with Y, but here it is!


Widget

[Tom Loizeaux]

Years ago, when I was first setting up my Altec Valencias, I heard about horn ringing so I cut a piece of clear vinyl tubing, sliced it down the length and slid it over the rear edge of the center vertical fin in the 811 sectorial horn.
I don't know how effective it was but it may have reduced some ringing - and it also probably reduced the beaming a little too.
They're still in there and those Valencias sound pretty nice.

Tom

[loach71]

I use some of the newer (rubber based as opposed to the old asphalt stuff) spray-on auto undercoating material to damp my metal midrange horns - like JBL 2345s. I first bead blasted the horns to get all the old goop off them - and get down to bare aluminum. After masking off the horn interior, I applied 4 medium coats of the undercoating.

After it was totally dry I removed the masking and spray painted all the surfaces of the horns matte black.

The horns do sound better - less "honky" - and the RTA / calibrated mike showed a cleaner response curve (around 1KHz to 2.5 KHz) than that delivered before the treatment.

Is this treatment the holy grail for metal horns? Probably not - but for the cost it seems worthwhile. Maybe the improvement is partially due to the placebo effect but I do like the results.

[Mr. Widget]

Is this treatment the holy grail for metal horns? Probably not - but for the cost it seems worthwhile. Maybe the improvement is partially due to the placebo effect but I do like the results.Yeah, the placebo effect that happens when you see a peak vanish on a frequency plot.:D

I'm sorry... I really don't want to be rude. I agree with those that suggest that listening is key, but the measurements are also pretty helpful at times.

...and to those that are running their horns stock... what the hell, they sold them that way. Enjoy them, but if you want, there have been several potentially useful tweaks shared on this thread.


Widget

[loach71]

Yeah, the placebo effect that happens when you see a peak vanish on a frequency plot.:D

I'm sorry... I really don't want to be rude. I agree with those that suggest that listening is key, but the measurements are also pretty helpful at times.

...and to those that are running their horns stock... what the hell, they sold them that way. Enjoy them, but if you want, there have been several potentially useful tweaks shared on this thread.


Widget

Agreed.

Sometimes one must become a "meter-reader" because psycho-acoustics are so damned flaky. No rudeness perceived - empiricism is needed in audio.

[mbask]

100% transparency cannot be achieved without an unacceptable loss in pertinent musical information
after lots of attempts late last night, I stand corrected
I'm leaving mine alone, they'er still the best.

anybody up for shots o Yagermeister:cheers:
35% non placebic :D

[Gary L]

I am on my way Mbask, Yeager could do wonders for some here but like my horns, I just enjoy it!

SO, Has anyone charted the sound that comes from 811Bs, ring or not, before dampening and after dampening?

I have to admit some of the charts and graphs tend to be over my head but I also have to admit they speak volumes to others.

I never go against real knowledge or science but often need some of it explained in laymans terms.
I am very thankfull that many intelligent individuals here are willing to take the time and explain some of this stuff in ways I can understand.

At times I do wish I had some Pop Corn to go with the Yeager so I could just sit back and read while I listen to the ringing in my ears.:applaud:

Is there any scientific info on before and after dampening 811B horns?
Does anyone have photos to show what they did to produce the results?

Thanks.

Gary

[Shane Shuster]

Has anyone charted the sound that comes from 811Bs, ring or not, before dampening and after dampening?
Gary
I had 511Bs that I damped using putty. They were mounted using the front baffle and from the rear. The frequency plot was so close as to be identical. Same with taking out the bug screen.

If you don't have them screwed down I would recommend that instead of messing with putty, dynamat, ect. Its easier and cleaner. I think guys hit the horn with their hand or an allen wrench and imagine the ring is worse than it is. I think its a scapegoat for the horn/driver combo's limitations.

If you do want to damp it you can kill the ring best by focusing on the middle of the upper and lower mouth lip.

[Mr. Widget]

I had 511Bs that I damped using putty. They were mounted using the front baffle and from the rear. The frequency plot was so close as to be identical. Same with taking out the bug screen.I don't know what you were using to generate your FR plot, but I have discovered that when comparing different amplifiers, the FR plot that I got using CLIO to measure the outputs of the speakers will not change at all at times and very, very little at other times... even when zoomed in enough to readily see 0.25dB changes and yet the sound is distinctly different.


If you don't have them screwed down I would recommend that instead of messing with putty, dynamat, ect. Its easier and cleaner. I think guys hit the horn with their hand or an allen wrench and imagine the ring is worse than it is. I think its a scapegoat for the horn/driver combo's limitations.
I agree. Baffle mounting any horn will affect it's performance... typically for the better. This is partly due to effectively adding mass and reducing the resonant frequency, but also it aids in the acoustic coupling to the room. I do think that dampening these horns is a good idea, but the effects are subtle as there are other "horn/driver combo's limitations"


Widget

[Steve Gonzales]

"Filter" presumably incudes equalizer.

So, we have determined the "ring" is at 4 kHz, have we?

I should just shut up, rather than sayin' stuff folks don't want to hear here.

Slide over, Giskard, buddy.... :) Naw, don't go and do that Zilch. I appreciate the science and the measurements you share ,although it hasn't seemed that way in the past. Any serious speaker system that JBL, or any other company has ever produced, was engineered/R&D'ed within strict science based guidelines, and wouldn't be anything near as good without those calculations/principles. I want you to know that my arguement in the past has been for a balance here on the site in regards to how much importance is placed on raw data over how something actually sounds in someone's system at home. Numbers don't always tell the whole story and ears can't always be used to get the most out of a system. I feel the need to go the record with this because I want you and everyone else to know that I respect and admire what you do here. I don't want to be thrown in the "anti-science crowd" because there is a HUGE difference between the aforementioned balance and the complete lack of respect for science demonstrated in certain posts within this thread. I hope you recognize that. Thank you Zilch, for what you do for the benefit of this Forum, Regards, Steve Gonzales

[Shane Shuster]

I don't know what you were using to generate your FR plot, but I have discovered that when comparing different amplifiers, the FR plot that I got using CLIO to measure the outputs of the speakers will not change at all at times and very, very little at other times... even when zoomed in enough to readily see 0.25dB changes and yet the sound is distinctly different.
Widget
I don't use anything as precise as you. I usually listen, then measure, then listen again. With the bug screen I didn't hear a difference, then measured, saw no change. Dampening the horn I thought maybe I heard a difference, then measured, no change. Listened again and thought I heard a difference. I left them damped for 4 months then decided to take the putty off. I did not hear a difference with the putty off, the new mod effect must have worn off over the months.

I think its a small enough difference that if you want to hear it you will, and if you don't, you won't. I'd take the cheap and easy way out.:)

But if you have the horn just laying on a bass cabinet with books propping up the back, it would help to damp the horn.

[Steve Schell]

This business of ringing horns reminds me of the similar controversy over compression driver rear caps and their removal or lining with foam or felt.

I once measured a bunch of JBL 2440 drivers on a 2350 horn with and without the rear caps in place. There was virtually zero difference in the response curves with the caps on or off. I have always preferred the sound of compression drivers with the rear caps removed however, so either I'm nuts or the FR measurements are missing something that I am hearing. I think it is the latter.

It is probably the same situation with cast metal horns. One fellow described to me an AES paper that he had read that discussed pre-echo in cast metal horns; I have not seen the paper. Apparently when driver energy hits the throat, the resulting vibration can travel through the metal horn and radiate from the mouth well ahead of the corresponding sound waves in the air column. This creates some confusing information for our brains to unravel, yet this artifact would probably be many dB down and not easily seen in conventional measurements.

[hapy._.face]

At higher volume levels- the ringing of the 811B is real and audible. Granted, they were never intended for higher volume level playing in the first place.

The ringing is not audible by itself but there is a bell sound to all the music coming out of it- like a harsh reverb. It's annoying.

Another thing to consider is the vibrations from the other drivers in the same cabinet impacting the horn. I prefer to mount (not sit) the horn outside of the cabinet.

All of the above mentioned ideas are great for sound isolation, but it won't make them stop vibrating. To do that- you need mass. A sand filled balloon in the scoop of the horn's front is ugly but very effective. I suppose one of those notepads might do the trick, too. Perhaps even concrete..(?)

When you eliminate the ring- you have yourself a pretty nice horn. They do 800Hz much better with some weight in them; I like them just fine for my purposes.

[loach71]

100% transparency cannot be achieved without an unacceptable loss in pertinent musical information
after lots of attempts late last night, I stand corrected
I'm leaving mine alone, they'er still the best.

anybody up for shots o Yagermeister:cheers:
35% non placebic :D

Make mine single malt scotch...
Jagermeister reminds me of Buckley's cough syrup!
:cooked: