Was there a 2" fiberglass bat between the boxes in the M19 box? Or perhaps some other type of pad / resonance trap?
It is mentioned in the service information of the manual. I was just going to line the upper box with insulation.
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Was there a 2" fiberglass bat between the boxes in the M19 box? Or perhaps some other type of pad / resonance trap?
It is mentioned in the service information of the manual. I was just going to line the upper box with insulation.
Don't recall seeing one and if I interpreted the assembly notes correctly, none was called for: Vintage Altec Lansing Model 19 Cabinet Plans
GM
Thanks GM,
I checked the plans, but they were not clear. That's kind of what brought up the question. I have never seen inside an original un-disturbed box. The plans call for lining the top sides and back of the upper horn box with 1 1/2" fiber glass stapled down.
The "service information" on page 2 of the manual says "the horn/driver assembly is accessible when the acoustic damper pad is removed" upon second read, I think it may be referring to a fiber glass bat stapled to the inside of the top box around the horn mounting bolts. That is not called out in the plans either?
as I understand the horn mounting, it is screwed in from the inside of the top box, I do not think they were talking about the "foam" fitted to the outside front of the horn box, but not sure on that either.
I still think originally there may have been a pad between the two boxes acting like a resonance trap? It is not mentioned in the plans though. I seem to remember reading that the some of the Altec cabinets were built by subcontractors. Maybe the drivers were installed at the factory and the pad installed at that time?
My M19s have no pad and all the pictures of 19s I have seen apart I have never seen one.
All I can say is that I had a DIYer's relationship with the local distributor that among other things allowed me to audition any new/whatever speakers, components and neither the sales prototypes nor the few I was exposed to early on had them, though over time I noticed the scrim to hide the stuffing disappeared in later units bought/sold by CMC Stereo as did at least some of the horn foam inserts.
Regardless, the cab acoustically is a crude dual chamber reflex, so not sure I'd want to damp down what little mid bass boost it offers, though I always damp the horn for any HIFI app to a greater or lesser extent depending on how/where it's mounted.
GM
Good info GM,
I will just do a nice job dampening the upper box and horn. Nice to know some of you guys were listening back in '76. Now I don't feel so old.:)
Some of us a lot longer.......... :Wince:
GM
They're referring to the foam damper that surrounds the front of the horn. Most 19's are missing them at this point, new ones can be sourced. When the foam is in plac it covers the mounting flange and screws holding the 811 in the cabinet. You have to remove the foam to remove the horn/driver.
Replacement foam for Altec Lansing 19 horns For Sale - Canuck Audio Mart
http://www.hostboard.com/forums/hbmc...2016/05/14.jpg
Thanks Bowtie
I guess I needed to know the horn was face mounted from the outside for that to make sense.
Sheesh I'm a rookie.
After 50 years of using Altecs I'm still learning...Quote:
Originally Posted by Nickd