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Help with over powering amp to cabs..

M

MBFrog

Feb 18, 2011
15
0
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#1
Ok posting here for some advice or fixes if anyone has or have had this issue, I will do my best to explain in 100 words or less!

I am getting some interested results from time to time and it varies.. now I have always changed batteries where needed once a month and cables checked every show.. so thats not an issue.. on the Carvin amp I am unable to turn up past 2 without sounding loud as heck and then it sounds like over powering the cabs.. ya know that amost busted speaker sound.. kinda like a bad fart.. and I dont like it..

Gear used with issues on sound:
Spector Basses with EMG-HZs w/ active/passive pickups
Carvin B1500 solid state amp
Output Pwr
8ohms 700w
4ohms 1250w
2ohms 1900w
Input Impedance: >200K
Hartke HyDrive cabs 410 -1000w / 115 - 500w @ 8 ohms impedance ea.
Both cabs indepently connect through speakon thus making 4 ohms, Carvin runs 1250w @ 4 ohms (done the daisy chain too no change)

Pedals:
Digitech BP200 which adds maybe 50w used at 65% vol and the chorus and reverb effects used with that are at 20% yet there is an Ashdown cab imulator effect I am using which has no power setting.. but dont know if that is the cause.

Boss Overdrive at 1/4 power and 1/10 overdrive blanced at 3rd tic, high/low at 12 o'clock

Tuner then a Noise Gate set at the 1 o'clock - for that bbzzz crap.. it works.

I have done the unplug and plug in trials.. still same - I know there is no way I am overpowering 1500w of combined cabs with 1300w of 4 ohm power.. or am I ? This is just for live sound.

if you understand and got advice.. let me know and thanks.

and yes thats more than 100 words..

the only fix I have heard was "go buy a Hartke Kilo amp for those cabs" which might be true but then again it was a Sam Ash saleman saying that too LOL
 
#2
I'm guessing your "500w" 115 is causing the distortion, although it could be both cabs. Speaker distortion is caused when a speaker reaches its excursion limit. The excursion limit is usually a much smaller number than the 'power handling' number, which is usually the thermal limit of a speaker. So, you're exceeding the xmax of the speaker or the point at which it can produce sound cleanly.

by feeding a single 15 the same power you're sending to 4 10 inch speaker, you're asking it to do 4x the work. It will be a very sad speaker very soon.
 
#3
Yep, that amp is easily capable of frying your speakers. Stack the 15 on top so you can better hear it when it complains. Check all your speakers independently, without using any effects, to see if you've already damaged one.

Volume knobs aren't representative of the power used, ie: half way up does not mean half power at all. You're likely setting some of your pedals too hot, which is overdriving the amp. That will make it so you don't have much wiggle room in the volume knob as you describe, and make the amp put out a lot more power than you think it is.
 
#7
MBFrog said:
Ok posting here for some advice or fixes if anyone has or have had this issue, I will do my best to explain in 100 words or less!

I am getting some interested results from time to time and it varies.. now I have always changed batteries where needed once a month and cables checked every show.. so thats not an issue.. on the Carvin amp I am unable to turn up past 2 without sounding loud as heck and then it sounds like over powering the cabs.. ya know that amost busted speaker sound.. kinda like a bad fart.. and I dont like it..

Gear used with issues on sound:
Spector Basses with EMG-HZs w/ active/passive pickups
Carvin B1500 solid state amp
Output Pwr
8ohms 700w
4ohms 1250w
2ohms 1900w
Input Impedance: >200K
Hartke HyDrive cabs 410 -1000w / 115 - 500w @ 8 ohms impedance ea.
Both cabs indepently connect through speakon thus making 4 ohms, Carvin runs 1250w @ 4 ohms (done the daisy chain too no change)

Pedals:
Digitech BP200 which adds maybe 50w used at 65% vol and the chorus and reverb effects used with that are at 20% yet there is an Ashdown cab imulator effect I am using which has no power setting.. but dont know if that is the cause.

Boss Overdrive at 1/4 power and 1/10 overdrive blanced at 3rd tic, high/low at 12 o'clock

Tuner then a Noise Gate set at the 1 o'clock - for that bbzzz crap.. it works.

I have done the unplug and plug in trials.. still same - I know there is no way I am overpowering 1500w of combined cabs with 1300w of 4 ohm power.. or am I ? This is just for live sound.

if you understand and got advice.. let me know and thanks.

and yes thats more than 100 words..

the only fix I have heard was "go buy a Hartke Kilo amp for those cabs" which might be true but then again it was a Sam Ash saleman saying that too LOL
Click to expand...

Bolding mine, obviously. There's your problem. You don't have 1500W of cabs. You have 1000 watts of cab. And that only if the 15" cab's power rating isn't exaggerated, which most of them are. Power is split evenly between cabs. At 100 watts, each cab gets 50 watts, at 200 watts, each cab gets 100 and so on. If you get to 1000 watts, it means each cab is getting 500 watts. That's the rated maximum of the 15" cab.

In reality, it probably starts farting out with far less power than that due to excursion. The rated power handling is probably the thermal limit, the point at which the voice coil will melt. Most speakers hit their maximum excursion at far lower power than they hit their thermal limit. Basically, the cone can't travel any further. That's what makes that "dying speaker" noise.

This is one of the reasons, but not the only reason, that lots of people on here recommend that you use matching cabs.
 
#8
^ thank you Satori - pfft nice of the specs on the manual to inform the buyer and user of such.. but your point seems valid and after I did some research from the prior post of FB'ers I have found a 410 to match and will be trading the 115 for it Sat.. again I will post my results.. it appears my initial gut theory before asking for advice has be validated here.

Frog
 
#13
I doubt very much that you've lost any bottom end. Bigger speakers don't necessarily put out more low end than smaller speakers, so it may be a case of "hearing with your eyes". But otherwise, with 8 10's, you should be capable of ruling the world.
 

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