LDS Cab in 4 or 8 ohms

#23
Morris Mulberry said:
Hey everyone! This is my first post on TalkBass and I was hoping all you guys and gals could give me some advice. I’m going to order a cab from LDS. It’s going to be a vertically aligned 212 with a 6.5 mid driver rated at 900w. I’m thinking of pairing it with either a GK MB500 (350w/500w) or a 700RB-ll (320w/480w). What I’m trying to decide is if I should get the cab in 8 or 4 ohms. If I understand correctly an amp can put out transient peaks up to twice its output...? Should that happen at 4 ohms with either amp I’d be over the cabs rated power. At 8 ohms I’d be alright. I don’t plan on getting another cab so future expansion isn’t a consideration. I just want to get the most “safe” power out of my head without damaging the cab. Thanks for your help!
Click to expand...
Key to this is your cab is rated at RMS watts, not peak watts. Peak watts are typically instantaneous, and not constant. You can get much more technical about RMS watts but basically the manufacturer is saying that it can take that RMS load on a constant (or at least somewhat constant) basis without damaging the speaker (unless you do something dumb like boost the bass EQ way up). Peaks of twice that power wont hurt it because everything has a chance to cool off in between the momentary peaks. If his 900-watt rating is in RMS watts, then it can handle 1800-watt momentary peaks.

As others have said, if this is going to be your only cabinet, then the 4 ohm version will get the most power to your cab. If you think you might want to get another cab later to add to it, then you should get the 8 ohm cab. That way you can add a second 8 ohm cab to get to your 4 ohm minimum load. If you put two 4 ohm cabs on the amp, that would equal a 2 ohm load. The heat from the amp trying to send that much power out over a 2 ohm load would melt things internally and release the "magic-smoke" unless it has a really good thermal protection circuit that cuts the power off entirely before that happens.
 
  • Like
Reactions: soflbass and BadExample
#25
Here is my old LDS 2126 that Don made for me in 2010. 3012LFs and an 18Sound 6.5 mid.

LDS_2126-1200_9724.jpg

Photograph Copyright © Jeffrey P. Scott 2010 All rights reserved.

LDS_2126-1200_9731.jpg

Photograph Copyright © Jeffrey P. Scott 2010 All rights reserved.

In 2009 he nade this cabinet, same mid driver with a pair of Ciare 8" neo drivers.
LDS-286_1280_8331a.jpg

Photograph Copyright © Jeffrey P. Scott 2009 All rights reserved.

LDS-286_1280_8337.jpg

Photograph Copyright © Jeffrey P. Scott 2009 All rights reserved.

I sold that one too, but to make up for the loss of those two great LDS cabs Don built me a pair of, even nicer, 1106 cabinets in 2014, with 3010LFs and Faital 6.5" mids. Wonderful cabinets. :)

Rig-1200_0085a.jpg

Photograph Copyright © Jeffrey P. Scott 2014 All rights reserved.

Rig-1200_0089.jpg

Photograph Copyright © Jeffrey P. Scott 2014 All rights reserved.
 
  • Like
Reactions: emjazz
You must log in or register to reply here.
Top Bottom
Back