Plenty of ultra low bass, but nothing from 40-100hz?

[tuna]

Im in the process of acquiring some cabinets that were built by somebody to house Eminence Magnums. The previous owner said that the boxes did a great job of producing ultra low end down around 20-30hz but not much in the usable frequencies between 40 and 100hz. Might anybody have any suggestions on a different driver that might help in a situation like this? The boxes were designed for dual 15" Eminence Magnums. What would cause the sound to go super low but thats it? Im acquiring the boxes at a great price and Im hoping to turn them into something I can use for outdoor events but I need to figure out a driver to use and a way to solve the super low sound problem. Any ideas?

[sine143]

maybe he put is lopass where his hipass should have gone

[Bill Fitzmaurice]

Im in the process of acquiring some cabinets that were built by somebody to house Eminence Magnums. The previous owner said that the boxes did a great job of producing ultra low end down around 20-30hz but not much in the usable frequencies between 40 and 100hz.

Magnums are not capable of doing much below 40Hz, in any cabinet, so the previous owner is mistaken.

[tuna]

I saw this was moved to the everything else forum. I just wanted to be clear that the cabinets Im talking about are modified Tuba 60 cabinets. They were built to be 36" square.


So the builder/previous owner was mistaken about something. But what could cause this result? The owner said the subs were moving air, windows and glassses were rattling but not much audible sound was coming out. How is that possible? He said he used an RTA mic to confirm the low low frequency sound (outside our hearing range?.

[Grant Bunter]

I saw this was moved to the everything else forum. I just wanted to be clear that the cabinets Im talking about are modified Tuba 60 cabinets. They were built to be 36" square.


So the builder/previous owner was mistaken about something. But what could cause this result? The owner said the subs were moving air, windows and glassses were rattling but not much audible sound was coming out. How is that possible? He said he used an RTA mic to confirm the low low frequency sound (outside our hearing range?.

What was the nature of the modifications?
How old are the cabs?

[Bill Fitzmaurice]

I saw this was moved to the everything else forum. I just wanted to be clear that the cabinets Im talking about are modified Tuba 60 cabinets. They were built to be 36" square.

Then it's not a T60. The Magnum is not a suitable driver for the T60 either. Based on those two points I would not buy them.

He said he used an RTA mic to confirm the low low frequency sound (outside our hearing range?.

If he doesn't know how to follow the instructions in the T60 plans I wouldn't count on him following the instructions on how to RTA response.

[sine143]

maybe they are the Tuba 36 then? the predecessor to the t60. I dont even know if the magnums were recomended in there. and regardless, it should still do just fine above 40 hz.

[Boyd]

I'd be questioning acquiring these cabs - sounds like you could be opening the proverbial 'can of worms'.

Having eaten 'can of worms' for dinner on too many occasions, IMHO it's rarely worth the hassle unless you have first hand performance experience with them.

[tuna]

Here is a link to the ad which include a picture.
http://sandiego.craigslist.org/csd/msg/3976447436.html

The price was free so I just would have to buy new drivers. The question is which ones.

[Radian]

The question is which ones.

Those are T36. Big ones too, at their full design width.

Original owner probably loaded them with Magnum HO's instead of LF's and low passed them at 80Hz.

Snagg'em up, series load'em with 3015LF's and low pass them at ~45 Hz using a 12-18 dB / oct Butterworth.

...Proceed to destroy the neighborhood.

[MissileCrisis]

The question is which ones.

Those are T36. Big ones too, at their full design width.

Original owner probably loaded them with Magnum HO's instead of LF's and low passed them at 80Hz.

Snagg'em up, series load'em with 3015LF's and low pass them at ~45 Hz using a 12-18 dB / oct Butterworth.

...Proceed to destroy the neighborhood.

+1 If you have no problem moving those monsters they should match close to a T60 IIRC. Someone can drag up a chart. I can't remember if they Vplate but that might be something worth looking into. I joined the forum after they were phased out but I would recommend loading them with whatever the premium drivers were at the time. You should have one hell of a PA when you're done but I'd make sure whatever drivers you do buy also work in one of Bill's other designs (i'm thinking lab 15's if they'll work, because T60's are awesome and they replaced the T36), that way if/when the cabs bite the dust or somehow don't work out you still have useful drivers, rather than ones that only fit the "free" cabs.

[Bas Gooiker]

I think 3015lf and Kappa pro's would be the recommended drivers.

[Bill Fitzmaurice]

I think 3015lf and Kappa pro's would be the recommended drivers.

If they're T36 the 3015LF or Definimax 4015LF are recommended. But there's no way any speaker will be loud from 20-30Hz and not at 40-100Hz, that can only happen via the user totally messing up the electronics. And the T36 didn't go below 30Hz either.

[doncolga]

I think 3015lf and Kappa pro's would be the recommended drivers.

If they're T36 the 3015LF or Definimax 4015LF are recommended. But there's no way any speaker will be loud from 20-30Hz and not at 40-100Hz, that can only happen via the user totally messing up the electronics. And the T36 didn't go below 30Hz either.

That's the first thing I thought from the OP.

[eshadeol]

OMG , Bill , please continue to stay alive, open minded, and informative. Your knowledge of the trade is highly valued by somebody such as myself who doesn't have the time or energy to seek out the book knowledge and retain what I read. Unless its in layman's terms and concise. I'm of the kinesthetic intelligence learning ability. We see with politicians who do seek extra fulfillment by testosterone driven brains and pleasures we all know, haven't been the types of people to learn by doing. = Career politician ruined by extra marital affair.lol. I'm not a bedside police officer , but please, not on taxpayer time.

Most importantly- stay healthy - stay WISE !