Wow--some great advice/info in several posts of this thread regarding fixing the resonance problems you're experiencing with your home-made cabs (adding bracing, using rubber, etc.). One of many testaments to how great the people here (and this forum) are. You might also want to consider trying your GPA refurbished 604's back in the original Heathkit AS - 101 cabinets that they were in when you bought them. As I mentioned in one of your previous threads (and also in a reply to one of the PM's you sent me), I used to own a pair of AS 101's. I played those speakers at volume levels ranging from extremely low to (what I consider to be) extremely high with all sorts or program material (music, movies, television--spoken word, etc.) and never once had any problems with cabinet resonance. Those Heathkit AS 101 cabinets are solid as a rock -- many prefer them to Valencia cabs although I've owned Valencias as well and never had any resonance problems with my Valencia cabs either (846A). Unfortunately, from your description of how bad your drivers sounded in those cabs, whoever modified your Heathkit AS 101 cabinets apparently didn't really know what they were doing and they seem to be horribly tuned at this point. Rather than turn those cabs into dog houses (although there are a lot of homeless dogs that would no doubt appreciate them), you might want to consider fixing the modifications that were done to them. If they were mine, I'd give them another shot -- nothing to lose but some time and potentially a lot to gain. I'd first remove the two "shelves" that someone added to them (possibly a failed attempt at dbr tuning?). Then I'd reduce the port size--from your photos and the port dimensions you posted in a previous thread the ports are most likely way too big. No wonder the drivers sounded horrible with those cabs tuned that way. You've experimented with different port sizes with your new home-made cabs (trial and error) to get them tuned optimally, I would suggest you try the same thing with the AS 101 cabs. If you want to go with the same empirical method, after you've removed the two shelves, just block off some (most?) of the port from inside the cab with a piece of wood "tacked" into place--experimenting to determine how much of the port blocked off sounds best. Once you find the ultimate sounding port size, screw the wood that you're using to block some of the port permanently/securely into place inside the cabinet. Or, build an "adjust-o-port" like you attempted at one point with your home-made cabs.... Tuned properly, those Heathkits should get WAY better bass response than the smaller home made cabs (I never had to add much bass EQ to my factory tuned AS 101's and they got GREAT bass response), so you'll most likely have to re-adjust your EQ or they'll sound like they're too boomy (too much bass) when they're properly tuned because in one of your previous threads you mentioned you had to add a lot of bass EQ for the duplexes to sound good in the smaller home made cabs (I would recommend that you reduce the bass EQ you're adding before you start experimenting to find the optimal port size). Switching from the home-made cabs to the (properly tuned) Heathkit cabs may also give you more accurate sound reproduction/cleaner more powerful sound and better/deeper bass because the cabs will be doing a lot of the work for you--the (properly tuned) cabs will be providing a much better bass response--which is preferable to having to add lots of bass EQ to compensate for small(er) cabinets. Let the Heathkit cabs do the work rather than adding a lot of bass EQ to compensate for the smaller home-made cabinets and you should have much more realistic sound with much less strain on the woofers which allows them to go louder/deeper and sound cleaner..... I'm not recommending that you don't fix/brace your home made cabs, I'm just recommending that you consider fixing the failed modifications that were done on your Heathkit cabs. If you do, I predict that you'll find they sound way better than the smaller home made cabs, and at that point you may decide not to fix the home made cabs (or maybe fix them for a future project)...... Just my opinion as a former owner of AS 101's--I LOVED the way those (rock solid) cabs sounded--and I know what kind of phenomenal bass and mids can come out of them with an Altec 15 installed (granted, a different Altec 15 and crossover), when the cabs are properly tuned.....Originally Posted by cradeldorf
Bookmarks