Help need with speaker

[omie]

I just ordered a Eminence Legend CB158 from USspeakers for a 1x15 ported cabinet. Approx 3.1 cubic feet.

I installed the speaker and at low volumes I'm getting a persistent static-y rumble... at med volumes the speaker is overdriving and at high volumes the speaker is cleaner but extremely mid heavy. I checked to make sure that the wiring was good, center tap is positive, 14 gauge speaker wire appears to be sound.. there is some oxidation on the 1/4" jack but the plug has rubbed it clean where it contacts... I could be mistaken, but.. i've checked and checked.... Any troubleshooting ideas?

Also, I've tried this with 2 amps and both amps are working fine thru my 2x12 cabinet but both amps sound terrible thru the new speaker/cab. I don't have the first clue of what I'm doing so I can't tell if its me or if I got a bad speaker.


Thanks

o

[Rick Auricchio]

Was the cabinet designed to use that speaker? If not, it's a crapshoot just dropping a speaker into an existing cab.

[craig.p]

Cab volume looks reasonable. Maybe the porting is not. Could be the 3-way mating of that cab and that porting and that driver has created a "boom box." Check the many threads on WinISD. Maybe one of the FAQs has info on it. Use it to model what you have, and you'll have your answer.

[will33]

Static sound usually means a bad wire connection somewhere. Does the cab have a tweeter? If so, make sure you didn't accidently hook it up to one of the tweeter wires. It is possible the thing got dropped during shipping and has voice coil rub in which case it is simply bad and needs to be sent back. While you're not playing it, gently push in and out on the cone and see if you can hear any little scraping sounds coming from inside the speaker.

[omie]

So the persistent static-y rumble can be caused by a bad cab/speaker match?

Basically, I drove a 2 hour round trip to pick up 2 empty 1x15 "bass cabs" only to determine that they were PA cabs. The port on these cabs is an approx 5 x 23 slot.


They were basically give-aways and I decided that at least the speaker grills, casters, recessed handles, 1/4 jack and metal corners could be useful. I spoke with usspeakers and ordered 1 legend, to try out the cabs with the thought that I would buy a decent speaker and try to build a cab if these cabs would not work.

[will33]

Are the high frequency horns mounted in there? Are they wired correctly? Do they work?

[Eric Moesle]

So you just blindly dropped that model speaker into an existing ported box that was not designed around that speaker?

There is your likely problem. It just doesn't work that way.

[will33]

Listen for the scraping sounds I talked about on the 15" speaker itself. If you don't hear any, test the speaker with a battery, it should jump. If it does, it's good and the problem is elsewhere in the cabinet. It's a PA cab, I'm wondering if you've got it wired to the crossover wrong or if there is a big hole in the cab where the tweeter is supposed to be.

[will33]

Originally Posted by Eric Moesle

So you just blindly dropped that model speaker into an existing ported box that was not designed around that speaker?

There is your likely problem. It just doesn't work that way.

Quite true, but, that legend is one of the friendliest there is for just dropping in cabs, it'll work acceptably down to 3cu.ft. and he has the option of sealing it if need be. Don't know what this thing is tuned to. If they used to be PA cabs they might be missing some other components = big holes in box. Some pics would certainly help this one.

[omie]

Yes, I did discuss the volume of the box with usspeakers... And then dropped it in, but again I ask... Is the low volume static/rumble a result of the cab/speaker combo.... The 9volt to + works as described.

[billfitzmaurice]

Originally Posted by Eric Moesle

So you just blindly dropped that model speaker into an existing ported box that was not designed around that speaker?

There is your likely problem. It just doesn't work that way.

+1. Not only will a poor box/driver match not sound good it also may result in a blown driver.

[will33]

These used to be PA cabs right? They have at least a high frequency horn if not also a mid driver right? Do they still have the crossover in them? Is your 15 wired up to a crossover that might be bad? Are all the holes in the cab other than the port plugged with something? A tweeter? Handles? Does your 15 make scraping sounds?

A lot of questions in this thread already you're not answering. Get this sorted out before you damage your speaker and maybe also your amp. That driver will work in that cab size as long as it's not tuned too high.

[1958Bassman]

Originally Posted by will33

Listen for the scraping sounds I talked about on the 15" speaker itself. If you don't hear any, test the speaker with a battery, it should jump. If it does, it's good and the problem is elsewhere in the cabinet. It's a PA cab, I'm wondering if you've got it wired to the crossover wrong or if there is a big hole in the cab where the tweeter is supposed to be.

The battery test is unlikely to make the cone 'jump' if it has the pleated surround. It should make a scratching or clicking sound but that's about all it's good for and means it works but has nothing to do with whether the speaker is good, or not.

If it's wired through the crossover, it will never produce any bass if the crossover has any kind of high pass or bandpass filter.

[omie]

There is no crossover in the cab, a simple quarter inch jack to the speaker is all.

I'll take pictures a little later and just say thanks to everyone for their input.