At what frequency are you experiencing the resonance ? That Eliptrac horn has a cutoff of 310 Hz. The 802's won't go that low..I personally would try to eliminate the resonance first.It should be an easy fix.
Any thoughts? Experience?
My 811b w/802-8g drivers have a bad resonance at a particular freq. (I have read all about this ringing on all of the forums, insulating coatings etc)
Thinking of replacing them with these 400 Elipitracs (wooden). They are offered as modern upgrades for Khorns. Pretty sure they wouldn't ring.
Eliptrac 400
Love the 802's BTW.
Thanks in advace,
I think its the design inherent "ringing" that many talk about, perhaps in combination with my Mac MA6500 amp.Originally Posted by Altec Best
My cabinets are extremely rigid, and the horns are well fastened and supported. I painted the outside with rubber coating before assly. Maybe much thicker coating?
Suggestions?
Just because people talk about something does not make it true. I do not believe there is ANY 'design inherent ringing".
It's the construction, not the design. You need to add MASS, not just rubber coating. One experiment I did was add modeling clay to the outside of the horn, I have seen sand mixed with adhesive apllied. A solution I saw was a seperate enclosure for the horn, it could be built into the top of the cabinet or seperate...and filling the backside with plaster. That worked well. You have to add enough mass to drop any resonance to below the horn's operating bandwidth.
Your neighbors called. They like your music.
If you can get away with crossing the woofer over higher to around 1,200 or 1,500 hz, I would just get some Mantarays like Model 14 used and be done. Better overall for home environment and wider dispersion. I have both 511/811 and love them but since I got some model 14 Mantarays, I'm MUCH happier in my 14 x 22 foot living room.
Its conical initial expansion is there specifically to reduce distortion/'ringing' for high speech intelligibility.
Yeah, cut the welds out of the vanes and hear it 'pop' due to the warping all that seam welding creates. Adding hard rubber wedges in the vane's gaps and damping/gooping' them like Altec did too late to save the sectoral horns in the marketplace, or at least fill them with a flexible caulking, makes a noteworthy difference, especially when combined with the extra damping
Cutting out the internal brace did similar on the much tweaked 511s I had. Better I found was to add stiffeners to the the horn's exterior to mimic the molded in ridges some other manufacturers had the good sense to do.
GM
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
We resorted to cutting a 511 in half, cleanup the entire inside, and pulling molds. We used fiberglass. We built a number of sets with strategically placed pieces of thin zinc between the fiberglass layers. No vanes, more mass, and cleaner transitions with no burrs. And ultra stiff. We had a few rejects we saved. A new guy was usually told to take it out back and break it up with a hammer.
The most anyone lasted before giving up was 45 minutes, 20 was about average. No one ever did it.
Hardest part was keeping a straight face when he came back in.
I am surprised we never had an employee go bonkers and shoot up the place. OTOH employees usually got in most local shows free since the promoters always owed us money. So there were perks, lots of free music and often beer. A business like that could not survive these days. I miss the 70's.
Your neighbors called. They like your music.
Hah! Good story OG. Love the bonus info we get here.
@OP - I did some measures a couple of years ago comparing some Altec horns. The "ringing" showed up, which I damped out with sandbags. You can see details in this thread.
- Mike
60's were better because cars were faster !!! The 70's were fun but the cars were mostly ugly dogs which kind ruined the era for me. Seems to me that music recording got better every decade. I often wish some of the 60 and 70's music could be recorded on modern equipment but since everyone is either old or dead that's not going to happen---damn shame.
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