Jay481985 Posted January 22, 2007 Share Posted January 22, 2007 maybe its like a ferrari, at first it was an accident in making the engine sound the way it was and now it is on purpose. Quote Link to comment Share on other sites More sharing options...
WopOnTour Posted March 21, 2007 Share Posted March 21, 2007 OK I've been reading old threads on using Dynamat to add damping to the K400 horn I've purchased a few sheets of Dynamat Xtreme commonly used to add damping to car doors What's the general concensus with respect to HOW to add the dynamat - between the horn and the cabinet like a mounting gasket OR - cover/coat the entire outer surface of the horn itself? BOTH??Appreciate advice that have done this modification themselves Thanks WopOnTour Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 21, 2007 Share Posted March 21, 2007 Naw, don't use it as a gasket. It is the main body of the horn that rings, and that is what you need to cover. Of course, I have the metal horns and I haven't done mine yet. I'm waiting for the time I am thinking I'm not satisfied with my LS and will do it to say, "oh yeah, that really made a big difference!" If I made all the changes at once, what would be the fun of that? Quote Link to comment Share on other sites More sharing options...
Groomlakearea51 Posted March 21, 2007 Share Posted March 21, 2007 Huhm, I recall this topic comes up every once in a while, and was "dissected" not too long ago... In any event, I've both types in K'horns and LS's. On one pair of K-400 K'horns, there was a ringing or "tinniness", sort of a resonance fairly high up. I had read everything last year, and tried the paint method, and even used "rhino liner". Worked ok, but something just did not sound right. Now they sounded "funny"... I had obtained a pair of old ca. early 70's spare 400's recently. They are not too terribly occupied with anything important...., So, I pulled the "offending" 400 (and the other one) out and compared them. The older pair was the same, the casting was a little rougher, and the flange had been visibly sanded flat at the factory. The newer one (the offender...) was more shiny, painted flange, BUT the flange showed uneven wear marks on the paint, but not on the whole flange surface. Huhm.... Swapped out the 400's, replaced the 55 driver to horn gaskets, installed, and it went away.... Went out to the workshop and flat edge checked the "bad boys"; they were not perfect "flat" on the flange mounting face. Belt sander.... Reinstalled, ringing completely gone, cant tell the difference between the 400's and 401's (identical amps, crossovers are all Bob's)..... That being said, when I reinstalled the "rehabilitated", horns, I did them vertical, and carefully cross-tightened (like cylinder heads...) the screws, little bit at a time to make sure that they were drawn flush evenly, then reinstalled the rear brace. Interestingly, that rear brace then did not match up quite correctly, may off about 1/32". Huhm... It's a thought. Maybe its just a matter of "blueprinting" the horns to the board faces more so than having to resort to rope caulking, or using special dampening paint. Another easy way to effectively dampen them would be to use a flange gasket of 1/16" neoprene rubber (like used for very large pipe gaskets, sold by the yard!!). I did that on my LS's several years ago to eliminate some bass reverberations that seemed to be running through the 400's, and used a small piece between the floor of the top bin and the metal support brace. Huhm... Just some thoughts... Quote Link to comment Share on other sites More sharing options...
meagain Posted March 23, 2007 Share Posted March 23, 2007 Didn't yet read this thread so forgive me if this has been brought up.... I have both types here. I've yet to test the ringing issue myself, but if I had to choose, I'd go for the k401. When I unscrewed the drivers to look into the horn, I found the k400 to have burrs, projections, flaws protruding right where the driver screen area is. I grabbed a small file and filed them down so they didn't protrude in front of the driver. Then, looking further down the horn, there are seams (I guess from the mold?), and I just can't imagine these seams being a good thing. They look to be about 1/8" or so. The k-401 is totally smooth at the neck and all inside the horn. Wouldn't smooth horn innerds be a more desireable thing? I would think so. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted March 23, 2007 Share Posted March 23, 2007 meagain To add some info to the differences in build quality....I have a few pairs of the K-400, K-401, and the Speakerlab HD350. The HD350 is identical in size, weigth, and shape as the K-400. However, the build quality of the HD350 is very refined. The cast imperfections that one sees in the K-400 do not exist on the HD350 casted horn. Quote Link to comment Share on other sites More sharing options...
whamo Posted March 23, 2007 Share Posted March 23, 2007 Couldn't you just use a hose clamp and say an inch or so of some radiator hose and tighten that around the horn somewhere to nullify the unwanted resonances to experiment rather than permanately altering the horn? Wouldn't that help? I'm thinking of it like a tuning fork. When it's vibrating and ringing you just grab it and there ya go. But in that theory mounting it to plywood should take care of that. But I don't know maybe it would help. Mark Quote Link to comment Share on other sites More sharing options...
Guest " " Posted March 23, 2007 Share Posted March 23, 2007 " I'm thinking of it like a tuning fork. When it's vibrating and ringing you just grab it and there ya go. But in that theory mounting it to plywood should take care of that. " Yes, properly mounted to include the driver base clamp. Quote Link to comment Share on other sites More sharing options...
meagain Posted March 27, 2007 Share Posted March 27, 2007 Somewhere here recently, BEC suggested trying rubberbands around the horn. I've not forgotten that suggestion as I thought it interesting. Like, the wide rubberbands that come with broccoli or asparagus. Unscrewing the driver and sliding a ton of these around the horn. Can double, triple them up. I 'think' this makes sense and is a good idea? IDK But it sure would be cheap and easly removed with scissors. Thoughts? Quote Link to comment Share on other sites More sharing options...
Jay481985 Posted March 29, 2007 Share Posted March 29, 2007 what about clay, or elmer glue with sand mixed in, or strapping tape? Quote Link to comment Share on other sites More sharing options...
WopOnTour Posted March 29, 2007 Share Posted March 29, 2007 So based on what I've read here so far I'm going to remove the horn and make sure the front flange mounting is a precise flush fit, and seal with putty Then I'm going to add the Dynamat sheets to the outside of the large bell portions of the horn (using the roller) and finally I'll use a large roll of 2mm soft rubber tape I found to add a few wraps up'n'down the round pipe/neck portions of the horn, replace the seals (cleaning out any internal flash at the seams) and carefully tighten the drivers equally. Then remount paying attention to making sure the mounting is secure. We'll see... WOT Quote Link to comment Share on other sites More sharing options...
Groomlakearea51 Posted March 29, 2007 Share Posted March 29, 2007 I'm going to remove the horn and make sure the front flange mounting is a precise flush fit, and seal with putty I would not seal it with putty... It will harden, likely crack and leak over time, and be a mess later; IMHO use a 1/32" thick piece of neoprene as a gasket to take up any "slack" on the motor board face... Another "blueprinting" trick is to "plane" that motor board face with say about 1/128" depth with a good planer, or a sanding block with say about 180 grit. Just enough to give your gasket a fresh face and some "grip". Please Post the results on what you find on the flange face; I'm personally very interested about that flange surface and it's "straightness" or "plane". I'm also wondering about the throat centerline being "perfectly" perpendicular to the flange. Could maybe be a key to the unexplained resonance that some have, while other's don't. Quote Link to comment Share on other sites More sharing options...
DrWho Posted March 30, 2007 Share Posted March 30, 2007 Somewhere here recently, BEC suggested trying rubberbands around the horn. I've not forgotten that suggestion as I thought it interesting. Like, the wide rubberbands that come with broccoli or asparagus. Unscrewing the driver and sliding a ton of these around the horn. Can double, triple them up. I 'think' this makes sense and is a good idea? IDK But it sure would be cheap and easly removed with scissors. Thoughts? You must really like asparagus.... [+o(] Quote Link to comment Share on other sites More sharing options...
Groomlakearea51 Posted March 30, 2007 Share Posted March 30, 2007 Old tire innertube? Wash it well, cut it round and round until its a single 1/2" wide strip, but about 20' long... wrap it around, cut of the excess, and secure it at the driver end with a cable tie/wire tie wrap? You could also start at the driver end and double up layers towards the middle of the throat. Quote Link to comment Share on other sites More sharing options...
Groomlakearea51 Posted March 30, 2007 Share Posted March 30, 2007 There is another possible dampening option; Find a "soft" dive weight, about 3 or 4 pounds or so.... they are in soft "pouches". Place it, to start with, about 1/3 of the way up the horn towards the throat. Put a rubber grommet between the rear brace bolt and the horn to isolate it further. That will kill it off. I tested it temporarily taped to a spare 400, and it does not "ring" anymore. Cheap ($2.00 maybe), quick, and can obviously be easily removed. Even slapped a couple on my 400's around the house just to see how it works. Can't really hear any difference because my ears are too old and probably worn out from gunfire, screams of pain from my kids, etc. and being hit in the head way too much when I was an idiot (still am, but learned to duck...), but... I think I detected a slight bit more "smoothness" in the LaScala's. Used a "known quantity" vocal track to test that. Quote Link to comment Share on other sites More sharing options...
IndyKlipschFan Posted April 7, 2019 Share Posted April 7, 2019 On 1/12/2007 at 10:48 AM, BEC said: From PWK's IEEE paper describing his "new" K-400 horn. Bob Crites Meaning after a tight screwing in there was no ring! Good to know. 2 Quote Link to comment Share on other sites More sharing options...
codewritinfool Posted October 3, 2019 Share Posted October 3, 2019 On 4/6/2019 at 7:39 PM, IndyKlipschFan said: Meaning after a tight screwing in there was no ring! Good to know. Wow. Get Dr. Freud on the line... Quote Link to comment Share on other sites More sharing options...
JohnA Posted October 5, 2019 Share Posted October 5, 2019 LMAO!!!!! 1 Quote Link to comment Share on other sites More sharing options...
MookieStl Posted October 5, 2019 Share Posted October 5, 2019 courtesy of @Tarheel worth reposting 1 2 Quote Link to comment Share on other sites More sharing options...
WMcD Posted October 9, 2019 Share Posted October 9, 2019 Maybe someone should try this on the inside and outside of the horn. Pick a color. 2 Quote Link to comment Share on other sites More sharing options...
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