calling all speaker guru's [message #3069] |
Thu, 18 September 2003 15:32 |
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hi all. i have a K100 2X15 blue sparkle kustom bass amp that i fully restored and i have a qustion about speakers.its rated at 50 watts rms and right now i have 2 webber 15's rated at16 ohms and 80 watts each.they seem to go into overdrive at half volume, sounds fuzzy. my question is can i use 2 emminence delta 15's rated at 350 watts rms 8 ohms. would this boost the volume or is it over kill? any comments would be greatly appreciated. thanks.
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Re: calling all speaker guru's [message #3071 is a reply to message #3069] |
Thu, 18 September 2003 23:21 |
ET
Messages: 146 Registered: October 2000 Location: Charlotte NC
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Senior Member |
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speaker guru here....the speakers...yeah...they're the round thingies in the big box under the amp...hey seriously..sounds like the amp is crappin out on ya more than a speaker problem...as you get into those higher wattage drivers, you'll be looking at larger mags, heavier coils (possibly), and I think you'll find that the little kustom amp just can't really push em..which some speaker gurus will tell you can cause added heat in the coil and actually damage a speaker..not starting an argument here..just heard that from some folks....what do I know...I just like the way they look....ET
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Re: calling all speaker guru's [message #3081 is a reply to message #3079] |
Sat, 20 September 2003 01:59 |
QModer
Messages: 413 Registered: June 2003
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Senior Member |
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Agreed you are over driving the germanium transistors in your little 100. I can get the same thing on a 200 if I run it (the volume) at about half way or more up with a bass.
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Re: calling all speaker guru's [message #3085 is a reply to message #3083] |
Sun, 21 September 2003 03:23 |
QModer
Messages: 413 Registered: June 2003
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Senior Member |
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None that I know of LOL. But lots of people like the geramium transistors so much that I've heard that one company may crank them out again just like they used to so that more of the old pedals using them can be reproduced. I kinda like being able to get the grit if I want in myself. Enjoy.
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Re: calling all speaker guru's [message #3088 is a reply to message #3085] |
Mon, 22 September 2003 10:40 |
C4ster
Messages: 686 Registered: June 2001 Location: Mukwonago, WI (Milwaukee...
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Senior Member |
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First off, Germanium transistors cannot be replaced with silicon transistors. They are biased differently and would throw the entire amp out of whack. Secondly, just because the amp's controls are only 1/4 up or less, doesn't mean that your amp is NOT putting out 50 watts. You are just driving the amp with a hotter signal. In '68, there were no onboard electronics on guitars and basses like now. If you have onboard electronics, you will drive your little amp to full output or worse, overload the input and distort there before you reach full output. And finally, make sure you are at 8 ohms or more. measure the resistance and if oyu are greater than 6 ohms resistance, you can be assures the impeadance is 8 ohms. if the resistance is 12 ohms or more, the impedance is 16 ohms. K100's hate anything less than 8 ohms and will distort prematurely.
Conrad
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Re: calling all speaker guru's [message #3089 is a reply to message #3088] |
Mon, 22 September 2003 13:24 |
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hi conrad. thanks for your input. i wiered both 16 ohm speakers in parralel so i would run at 8 ohms. the only other thing i can think of is maybe the problem is that one of my speakers is deffective.i will try to isolate each speaker and see if one of them is no good. i just have to pick up a 16 ohm resistor at radio shack to put across the single speaker.john
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Re: calling all speaker guru's [message #3090 is a reply to message #3089] |
Mon, 22 September 2003 13:48 |
C4ster
Messages: 686 Registered: June 2001 Location: Mukwonago, WI (Milwaukee...
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Senior Member |
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Don't bother with the 16 ohm resistor. It will run just fine on 16 ohms. The resulting output will reduce to about 35 watts at full signal. To really test it would require a scope, signal generator, and meter. There may be something else wrong that could be isolated with a full power test.
Conrad
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Re: calling all speaker guru's [message #3105 is a reply to message #3081] |
Thu, 25 September 2003 08:11 |
stevem
Messages: 4774 Registered: June 2004 Location: NY
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Senior Member |
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HI, to put it simply, if your pilot light is dimming a good amount when you reach the volume level of hearing distortion, I would bet that the amp is OK and is putting out is rated 50 watts RMS. which is not alot for bass even with good speakers.back when I started out with a k100 with the 2 12" cab, playing rock that lasted about a year, then I went to the k200 with the CTS drivered 3-15" cab, that lasted about another year then I traded in the k200 head for k250. That was a big change, but the big improvement was dumping the 3-15 cab for a 2-15" cab loaded with Electrovoice or EVM speakers. 50 watts is a good amount for a studio session, or rehearsal with a light hitting drummer and guitar players with out 4-12" cabs. remember it takes 4 times your current 50 watts to dubble your volume that your ears hear.going from 50 watts to 100 will give you twice the amount of clean head room before the amp goes into distortion. These old amps do not need alot of input signal to drive to full output, you may be just overdriving the preamp into distortion mainly.If you put a Ohm meter across the cabs speaker jack it should read any where from 5.5 to 6.8 ohms for a rated 8 ohm cab. If you then put a voltmeter across the same way but set for A/C volts you should see 20 volts which would be 50 watts RMS and 28 volts for 100 watts peak. The easyest wat to double the sound pressure of a amp which is what you ears hear, is to double the speakers. (IE) MOVE MORE AIR.CTS speakers are rated at about 94 DBs going to a eminence model like their 15" Kappa serise at 102 DBs will give you allmost twice the output at your current amp setting allowing you to back down the amp and clean it up. But in my way of thinking 100 watts RMS is the number to start with for bass, THE MINIMUM.
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