Yes, my subs are old enough to drink!
I thought that this would be pretty straightforward but as I read more I realize it is a complicated question so I'm reaching out in hope of some advice.
I have a 21 year old home theater with California Audio Tech speakers. One of the subs started making a clackety sound and when I pulled the cover I found the speaker surround material was crumbling.
There are two 12" subs each in its own cabinet composed of 1" thick MDF measuring (outside) 32" wide by 26" high by 9" deep. I think that gives them a volume of 2.92 ft**3 (30"x24"x7")/(12**3). The boxes are stuffed with some fluffy fill material. I pulled the bad driver to see if I could figure out the brand but it is un-marked other than an embossing on the cage that says "Empire". They are single 4ohm voice coil. I'd like to replace the drivers and would love some advice on options.
pictures below.
Help/Advice deeply appreciated!
Thanks, Bob
p.s.
I'm not sure it is relevant to the question but just in case... there's an Anthem AVM60 with the subwoofer out connected to a Crown XLi3500 serving as the subwoofer amp in parallel mode with one output driving each of the two sub woofers. This is a new amp to me... and if you think this is a stupid choice please let me know. I had an ADA PBA-2000 driving the subs... a thermistor in the slow start circuit blew up. I replaced the thermistor and the amp worked again but the age of the amp was making me nervous, and I wasn't brave enough to recap the thing and that sub was making the clackity sound... which I didn't bother to really look at till after I replaced the amp and it didn't get better 🙁.
I thought that this would be pretty straightforward but as I read more I realize it is a complicated question so I'm reaching out in hope of some advice.
I have a 21 year old home theater with California Audio Tech speakers. One of the subs started making a clackety sound and when I pulled the cover I found the speaker surround material was crumbling.
There are two 12" subs each in its own cabinet composed of 1" thick MDF measuring (outside) 32" wide by 26" high by 9" deep. I think that gives them a volume of 2.92 ft**3 (30"x24"x7")/(12**3). The boxes are stuffed with some fluffy fill material. I pulled the bad driver to see if I could figure out the brand but it is un-marked other than an embossing on the cage that says "Empire". They are single 4ohm voice coil. I'd like to replace the drivers and would love some advice on options.
pictures below.
Help/Advice deeply appreciated!
Thanks, Bob
p.s.
I'm not sure it is relevant to the question but just in case... there's an Anthem AVM60 with the subwoofer out connected to a Crown XLi3500 serving as the subwoofer amp in parallel mode with one output driving each of the two sub woofers. This is a new amp to me... and if you think this is a stupid choice please let me know. I had an ADA PBA-2000 driving the subs... a thermistor in the slow start circuit blew up. I replaced the thermistor and the amp worked again but the age of the amp was making me nervous, and I wasn't brave enough to recap the thing and that sub was making the clackity sound... which I didn't bother to really look at till after I replaced the amp and it didn't get better 🙁.
presume those boxes are sealed?
Most 12"subs nowdays(21 years later that is)are designed for much smaller enclosures 3cf is large most are around .8 to 1.6cf to maintain the flattest response (Qtc .7)
Putting them in a larger vol is ok you will gain a lower F3 but at the expense of power handling and possibly even more distortion if passing xmax, just keep it in mind with how much power you feed them.
Just about any 12" 4ohm at Parts Express will be ok, although some of the high excursion subs physically won't fit with only 7" depth.
Most 12"subs nowdays(21 years later that is)are designed for much smaller enclosures 3cf is large most are around .8 to 1.6cf to maintain the flattest response (Qtc .7)
Putting them in a larger vol is ok you will gain a lower F3 but at the expense of power handling and possibly even more distortion if passing xmax, just keep it in mind with how much power you feed them.
Just about any 12" 4ohm at Parts Express will be ok, although some of the high excursion subs physically won't fit with only 7" depth.
I would also try to replace the surround first, I did that on some 10" JBL woofers and it is not that difficult - I got some generic foam surrounds of correct size and watched a few YouTube videos.
Thanks!
@Harry72. Yes they are sealed. Will a driver with a higher power rating reduce the risks you cite? And/Or should I be looking for the highest xmax that fits in the enclosure to provide more headroom?
@maudio and @pelanj - I didn't realize that I could replace the surrounds. Maybe I will try that. I was worried that having run it for a a little while with the busted surround that I might have done some damage to it. And I was wondering if the state of the art had improved so much in the last 20 years that maybe a modern driver would be the way to go but it sounds like the assumptions about enclosure designs have changed (I wondered about that when I saw the low volumes recommended in the driver specs).
@Harry72. Yes they are sealed. Will a driver with a higher power rating reduce the risks you cite? And/Or should I be looking for the highest xmax that fits in the enclosure to provide more headroom?
@maudio and @pelanj - I didn't realize that I could replace the surrounds. Maybe I will try that. I was worried that having run it for a a little while with the busted surround that I might have done some damage to it. And I was wondering if the state of the art had improved so much in the last 20 years that maybe a modern driver would be the way to go but it sounds like the assumptions about enclosure designs have changed (I wondered about that when I saw the low volumes recommended in the driver specs).
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I just wanted to reply back and say thank you for the advice. I ended up replacing the surround using a kit from simplyspeakers.com. They were very helpful. My repair doesn't have the aesthetics that a more experienced person but it seems to function well. Saved me hundreds of dollars.
I had my 12 inch hpm900 woofers reformed
They are like new now. Voice coils have to be good not ruined by use at high power with no foam surrounds.
They are like new now. Voice coils have to be good not ruined by use at high power with no foam surrounds.