Marantz HD770 Re-Foam Help

[ahk26]

A friend of mine asked me to help him re-foam his Marantz HD-770’s. He had sent the woofers somewhere awhile back and was quoted $150 to repair them and said no so they were sent back to him. I agreed to help him but when I got them home I noticed that one of the woofers does not have a dust cap but it is shimmed like the other repair guy was ready to replace it (I have re-foamed several sets of speakers but never had to replace a dust cap before). My question is first does a regular dust cap work but just get installed in an inverted position? If not is there a special dust cap for this model and any idea where to get one? Lastly I understand the shims are to keep the cone aligned but when I install the new dust cap do I just pull the shims out and glue the dust cap in? Thanks in advance for any help you can give me (secretly I am hoping my friend will sell me these HD’s sometime, he is using them as part of a surround sound system that is not worthy of these awesome vintage speakers!)

 

[MarkAnderson]

My question is first does a regular dust cap work but just get installed in an inverted position? If not is there a special dust cap for this model and any idea where to get one? Lastly I understand the shims are to keep the cone aligned but when I install the new dust cap do I just pull the shims out and glue the dust cap in? Thanks in advance for any help you can give me (secretly I am hoping my friend will sell me these HD’s sometime, he is using them as part of a surround sound system that is not worthy of these awesome vintage speakers!)

You may be able to get the correct style caps from a JBL reconer or such. Some of their woofers used inverted caps...

Or, you could use a standard cap with the glue flange removed...

Or, you could use a standard cap mounted the standard way (depending on how anal your are about cosmetics, originality and all that)...

The shims must come out before the new cap is glued on.