The Eminence LAB12 I purchased sometime back in 2008 and have been abusing in my home theatre setup ever since finally had the coil slap the magnet a few too many times. One final POP! during Spiderman no way home this past weekend and it went into fart noise mode.
It bottomed out occasionally ever since being installed in the Besta cabinet. It turns out that little bit of power limit that shows in the model was in fact dangerous and movies would hit that 30Hz spot hard. From my initial analysis on that page I thought “this shouldn’t be a problem”
That was in fact a problem it seems. The old 200W plate amp shouldn’t have been able to over power the woofer, but it did. Likely I was clipping it a bit when it bottomed the woofer. Funny thing about clipping a subwoofer amp, it’s not as noticeable as it is on a full range speaker. That distortion is easily hidden by all the rattling things all over the room at that point.
And now for the replacement, dropping in with the same diameter hole and 8 machine screw threaded inserts to match to the 3.4 cube box tuned to 22Hz. I spent way too much time agonizing over different models to make a decision.
The red line is the GRS 12SW-4HE, the orange is the RSS HF sub that shows a very slight advantage. The yellow trace is the MX12-22 which appears to like a smaller box and / or a little higher tuning. I also modeled the Ultimax II, which looked very similar so I didn’t end up saving it.
All of them work without that over-excursion threat in this box. The GRS is maxing out at 108.5dB @ 250W, the RSS at 111.6dB @ 400W and the MX12 at 115.5dB @900W. Using my same 200W plate amp, those SPL advantages disappear.
I couldn’t help but go with a GRS. Based on the cost and specs this should by all counts be a downgrade. Even though other options like the RSS or the MX12-22 all model well, they don’t have much of an advantage over the GRS unless I also pump at least twice the power into them. The remaining variables are if the GRS specs are reasonably accurate, and if there is a distortion difference in the higher end drivers. I have an 8" version of that GRS and it’s specs do measure close enough to published values to make the modeling good. About the distortion, I’m sure there is a difference but doubt it’s large enough to matter in my application. Ultimately the GRS was about 1/3 the price for similar performance so it won! It arrives today and should be back in service very quickly.
If you are ever interested… I have a new/unused Lab12 sitting on the shelf that I would sell you for a very fair price. Zero tax or shipping cost if we both end up at InDIYana this Spring
I’ll be curious to know if you think one GRS will be enough for your room. I gave our son my two LAB12s after some old plate amps dumped 40+ VDC on his GRS 12s. I think two of the GRS were more than enough for his smallish living room. He tells me the LAB12s with an 800W/ch QSC amp can shake the entire house.
That was definitely a concern with the cheap woofer. Ultimately I’m not a huge purist for my HT setup, I’m slightly ashamed to admit that I’m still using the super cheap Dayton book shelves for the R/L mains. Nasty for distortion and not for critical music listening, but after the Yamaha APO adjustment they’re perfectly acceptable to me. The 3X cost of the RSS was just too much to justify. Down the road when I do a proper 5 channel DIY re-build it may be time to upgrade the sub driver and amp.
It’s up and running! Did some sine wave abuse to make sure it was working properly, and it does the job. I don’t have a lead to watch the signal with a scope, but I did hear a decent amount of distortion when pushing 30Hz uncomfortably loud. I was likely clipping the amp as well as pushing Xmax too far. In it’s home position it works well. When that down-firing port kicks in hard at 22Hz the whole dang living room floor is shaking, mission accomplished!
For future nerdery, I have an RSS 10" to compare for distortion. I’ll do a close mic sweep at a decent SPL between the two woofers and see if driver distortion is a factor. A bit of apples vs. oranges but could be interesting.
It definitely is for normal people. Folks on a message board like this are not normal people, so a couple of them or more cone would be great. I’m satisfied though, but I’m sure I’ll hit it’s limits on occasion with a loud action movie.
Seems like your amp is the weak spot. I don’t have any experiance with that driver but have killed its GRS little brother it really didnt do well when pushed to its limits.
I would be interested in the Lab 12 if you don’t have any plans of reconing it.
