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Seismic Quad 18ís

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Bob Faulkner:
hmmm... looking at their specs and the wording that is used to describe the cabinet, this looks like a 4-speaker cabinet with 2-speakers on one pair of wires and the other 2-speakers on another, separate, pair of wires.

CONNECTORS:Two 1/4" and Two Speakon per side

The power ratings shown on their website and on the back of the cabinet appear to point to two independent "pairs" of speakers.

POWER RATING: 2 x 1200 Watts RMS; 2 x 2400 Watts Peak
NOMINAL IMPEDANCE: 2 x 4 Ohms

Looks like the cabinet would need two separate amplifier channels for its full utilization.

The term "Quad-18" is correct; However, it may not mean all 4 speakers work together.

I do NOT trust anything Seismic puts on their website. 

As a side note on speaker cabinets, many (many) years ago, I swapped out a Peavey 18" speaker (from a Peavey 118 sub) with an RCF 18" speaker.  This was so I could run my Crown PowerTech 3 amps in bridge-mode (1500 watts @8ohms) on each cabinet.  The cabinets only had 1/4" inputs (2).  The pressure from the speaker blew the 1/4" cables out every time.  I changed out the 1/4" to Speakon... which resulted in the cables staying in, but the pressure from the driver eventually destroyed the cabinet (blew it apart slowly), over about 2 years. 

There was nothing wrong with the Peavey 118 cabinets; I'm sure it just wasn't designed to handle that level of pressure.

Steve-White:

--- Quote from: Ivan Beaver on February 06, 2024, 08:19:53 AM ---You cannot "flip something out of phase".  You can only flip the polarity.

Yes there is a big difference. "out of phase at one freq will be in phase at other freq".  Out of polarity will be out at all freq.

You need to think in terms of wavelength.  50Hz is roughly 20' long.  6" is nothing at that freq.  At 2Khz, that is a completely different issue.

--- End quote ---

Thanks for this Ivan.  ""out of phase at one freq. will be in phase at other freq".  Out of polarity will be out at all freq."

I used to mix the term phase with polarity.  This puts it real clearly why not to do that as they are in most cases vastly different.

lindsay Dean:
Well they had them set up correctly in the beginning forward-facing The only problem was they didn't  have them forward faced into the dumpster 👍

Steve-White:

--- Quote from: lindsay Dean on February 07, 2024, 02:07:48 PM ---Well they had them set up correctly in the beginning forward-facing The only problem was they didn't  have them forward faced into the dumpster 👍

--- End quote ---

The Bose/Pyle dumpster?  :)

Chris Hindle:

--- Quote from: Steve-White on February 07, 2024, 04:20:06 PM ---The Bose/Pyle dumpster?  :)

--- End quote ---
.... to give a soft landing to Accordions and Banjo's. 8)
Chris.

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