Question on amps...

Discussion in 'Amps and Cabs [BG]' started by Grahams Groove, May 23, 2001.

  1. I ordered a nemesis NC-115P Combo amp earlier tonight off of an online music store and im having a slight problem...hopefully you can help. On the site ( it says that the power rating is "225W @ 4 ohms" but it does not say how many ohms the 15" driver is. So i assumed the driver was 4 ohms. Then i was reading a few reviews, and bassplayer in particular had a review that said the amp was "225 watts RMS into 8 ohms". Then i read a review page by some other guy that said that the amp itself was 225 @ 4 ohms, but that the speaker was an 8 ohm speaker(In this case, how many watts would be going into the speaker????) So my question is, what is it????? I am led to believe that it is 225watts RMS into 8 ohms, because i believe bassplayer reviews all the gear, and thoroughly examines it...but i am still unsure. Can anyone help me out. PLUS, to make it all more exciting, i need to get it figured out by tomorrow, so i can cancel my order in the AM if need be.

  2. What you have is an amp capable of handling a 2nd 8-ohm cabinet. They are quoting you a spec of total wattage at 4 ohms, assuming you might want to run that 2nd cabinet.

    The amp will deliver less power into 8 ohms than it will into 4 ohms. This is a bit deceptive because you have to be running the amp wide open to get full power. You will be clipping and farting before that. You will make more noise with a 2nd cabinet.
  3. Any combo amp that has a external cabinet output and that is rated @ 4 Ohmns will run an 8 Ohm internal speaker. SWRs, Fenders, you name it.

    That way, as long as you don't run anything lower than an 8 Ohm extension cab, you can get the full power @ 4 Ohms without blowing the combo up.

    Power output @ 8 Ohms would be ~ 150W (there's a formula, but i'm no sparky, but generally output @ 4 Ohms is almost twice that of the output @ 8 Ohms).

    From the Eden website:

    Model NC-115
    Price $890.00
    Size 23.75"W x 23.75"H x 16.25"D
    Weight 62 lbs.
    Speakers 1-ES 1560
    Tweeter 1-E2700 Horn
    Power @ 4 Ohms 225 Watts RMS
    Frequency Response 38 hz - 15 khz
    Sensitivity 98 db/SPL

    So there you have it. 225W @ 4Ohms. And here's the speaker inside the Nemesis:

    Model N-115P
    Price $464.00
    Size 23.75"W x 23.75"H x 16.25"D
    Weight 55 lbs.
    Speakers 1-ES 1560
    Tweeter 1-E2700 Horn
    Power Handling/Impedance 200 Watts RMS - 8 ohms
    Frequency Response 38 hz - 15 khz
    Sensitivity 98 db/SPL

    So it is indeed an 8 Ohm speaker.

    Hope that helps! :)
  4. The only thing is, from what ive heard, the amp is wired oddly so that when you add an extension cab, it doubles the ohm load instead of cutting it in half...i know it doesnt sound right, but thats what ive heard...But if you have this amp or somehting, ill totally take your word for it and all...i just want to figure this all out before the order goes through.
    Any second thoughgts?
  5. Oops...ok, what you said makes perfect sense. So this means i would need an extension cab to get the full 225???? Also, then i have a second question. Could i run a 2x10 extension cab rated at 4 ohms? or would i need to do another 8 ohm 15" speaker?? Or if you could, tell me the specs i need to look for in an extension cab to find one that is compatible.
  6. One other question. On the site it says this
    "The extension speaker jack is wired in series, allowing most models to deliver their maximum power to the internal speakers and allowing users to safely add almost any extension cabinet."

    What does that mean?? (wired in series...?)
  7. It is possible to have jacks with internal configurations that put a 2nd cabinet in series with the first cabinet.

    This results in a lesser total power delivery due to the higher impedance. Contact the manufacturer, or RTFM (read the friendly manual) if available on their web site, and find out the exact power requirements. If the main cab is already 4 ohms, you will almost certainly have to run a 2nd cab in series.

    Typically, try to power yourself at least 4x more than the guitar player's amp. At a minimum.
  8. Yup, an extension will take the total power output to 225W. You can run ANY extension cabinet with the combo, provided that it is rated no lower than 8 Ohms (a 4 Ohm extension would bring the total load down to ~3Ohms, which the Nemesis could probably handle, but could possibly blow it).

    The fact that the extension is in series (which means that additional speakers daisy-chain from one another and ADD to the total impedence - eg an 8Ohm extension would make the total load 16Ohms, which the combo can handle, but with a lower total volume) confuses me though - it almost sounds like the native power output of the combo is set @ 4Ohms, regardless of what impedence speaker you use (which is possible, and safeguards against attaching an extension that drops the total load too far).

    Unfortunately I don't own one, just basing this on my experiences with combos and extensions in the past.

    Have you tried calling Eden's customer service (if they have one)?
  9. OK,
    I called eden(nemesis) today and here's what they said. They said that the amp can run 225 @ 4 ohms. So, the guy looked at the manual and said that with the 15" (8 ohm speaker) the amp runs 200 watts RMS and can peak at 125 watts as opposed to haveing something like the 2x10 where you are running 225 RMS. So the only difference is the cone size and a bit of headroom. This makes perfect sense me any ways.
  10. On that last post it should say that it can peak at 225 watts, not 125.
    That make sense to anyone else????
    What do you think would be louder? Keeping the 1 15" speaker pumping alone at 200 watts RMS, or adding say a extension cab of 2x10's, or another 1x15??? (Note:The ext. speaker jack is wired in series, so when you add a ext. cab, it doubles the ohm load making for less wattage being "pumped out"...)
  11. Generally, adding an extension cabinet will add to your overall volume. Obviously if you're connecting in series forever there will be a point at which the headroom of the amp won't be sufficient.

    I'd look at adding a 4 or 8Ohm extension speaker (if the extension is series, then a 4Ohm'er will probably be better - actually you could replace the internal 15" with a 4Ohm 15", and with a 4Ohm extension give you an 8Ohm total load), i'd probably look at a 2x10 (non-tweeter). The 2x10 will give a crisper attack and punch than the 15", the 15" will still provide good lows.

    But, as with anything musical, you *really* need to try it out for yourself - you might find a 15" extension to be the icing, or maybe a 4x10, or...

    The power rating kinda makes sense - 125W @ 8ohms, 225W @ 4ohms, although i'd say the amp would always be delivering into 4ohms, regardless of what speaker(s) are connected. Which, if this is correct, means that you could get the combo re-wired to allow the extension to be connected in parallel, allowing you to run the internal @ 8ohms, the extension @ 8ohms, for a 4ohm total load (thereby getting max power from the amp).

    DISCLAIMER TO THE ABOVE: I don't own a Nemesis combo, nor am I a qualified amp tech. The above observation is just that; an observation based on experiences and some degree of mechanical/electrical skill. I would run this idea past an amp tech before trying odd things. Don't want you to kill the amp now! :D But, FWIW, I hope this helps a bit...