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Fender Bassman 4x10 and 1x15 - What Amp would be optimal?

Discussion in 'Amps and Cabs [BG]' started by GENRLEE, Jul 27, 2012.



    Jul 16, 2012

    I'm a newb here and have seen several posts about amps and wattages and cabs but none specifically for what I am needing. My current rig is a Fender Bassman 250 Head powering a Fender Bassman 4x10 and Bassman 1x15 cab. The cabs are rated at 8ohms. The 4x10 shows 700 Watts (Program) and 350 Watts (Continuous) at 8 ohms. The 1x15 shows 500 Watts (program) and 250 Watts (Continuous).

    The head is just a 250 Watt head. I know I'm not getting the full 250 watts when using both cabs. I'm wanting to upgrade my head to at least a 500 or 600 watt. What would be the best configuration needed for what I'm looking for?

    Please don't use any technical jargon as I don't know what any of it means. :eyebrow: Just simple layman's terms will suffice. Thank you in advance!!

    The style of music I play varies from Blues to Rock to Hard Rock/Classic Rock. If that information helps in any way.


    Jul 16, 2012
    As a reply to the original msg, Recently I played through an Acoustic B600H head and loved it. Did not play through my cabs though but used the 8x10 Acoustic cab that came with the head. The Acoustic shwos it is a 600 watt head at 2 ohms, 450 @ 4 ohms and 250 @ 8 ohms. If using this head on my fender cabs, would I get the 450 watts to both cabs since my each of my cabs are rated at 8 ohms?
  3. Pilgrim

    Pilgrim Supporting Member

    If you don't want any technical jargon, you're never going to learn what you're doing. If you work with electrical equipment, you need to understand it.

    There is a Bassman 250 manual (which you should bookmark) here: http://support.fender.com/manuals/bass_amplifiers/Bassman_250_(2005)_manual.pdf

    If you have two 8 ohm cabs connected, the impedence your amp sees is 4 ohms, which according to the specs on page 8 appears to be the minimum permissable impedence. This is not technical jargon, it's simple information.

    The manual says "POWER OUTPUT: 250W R.M.S. into 4&#937; @ < 0.05 % T.H.D., 100Hz". This means "250 watts into 4 ohms at less than .05 percent total harmonic distortion at 100 Hertz." (You're probably not worried about the distortion spec, but it is to your advantage to learn what it means.)

    In very simple terms, if you connect both of your 8 ohm speakers to create 4 ohms of impedence, you are enabling your amp to output every watt of power possible. Your statement that "I know I'm not getting the full 250 watts when using both cabs" is incorrect.

    If you have efficient cabs (search for "efficient" here on TB, I'm not going to explain it) a 250W head will get very loud. If you upgrade to a 500W head, you can get louder, and you will be pushing those cabs about a hard as is wise. However, by doubling the power of your amplifier, you will only increase the loudness by 3 decibels of volume. See http://www.bittner-audio.com/default.php?page=pow2vol&l=en and even better, check this article at Harmony Central: http://www.harmonycentral.com/docs/DOC-1951.


    Jul 16, 2012
    Sorry for not wanting the technical jargon yet. I do plan on learning more about it. You really don't have to be hateful about it or make your statements seem hateful.

    Although your answer is very informative and I am very appreciative of your knowledge in this area, it doesn't answer my original question.

    What would be the optimum head that I could get to power my existing cabs? Would the Acoustic B600H head be a good match for my existing cab configuration? If not, what would you suggest?
  5. Hold On Now!

    Pilgrim ain't layin' no hate on nobody!

    More in a moment.

    (Just got home!)

  6. Pilgrim

    Pilgrim Supporting Member

    I've done some editing and softened my earlier wording. My goal was to get your attention, and it appears that it worked.

    There are tons of heads out there, and "optimal" is a term that depends entirely on the tastes of the user. If optimal means a head that pushes the cabs harder, then more wattage will do that, but it's not going to make the cabs significantly louder. You can do nearly as much by running your current head at higher volume.

    With the same cabs, if you get a 500W head that you're playing at maximum volume, you will be 3 decibels (db) louder than your current head played at maximum volume.

    It has been commented here in many threads that two 4x10 cabs will sound louder than a 4x10 and a single 15. In responses, you may get suggestions to ditch the 15 and get another 4x10. If you can find efficiency specs for your cabs (do a Google search for the specifications) they will be expressed as something like: Sensitivity at 1W/M, 99 db. That means that when 1 watt is applied, the sound level 1 meter from the speaker will be 99 decibels.

    It will be easy to understand that a speaker rated 92 db at 1 watt is not as loud with a given power input as one that's rated 99 db at 1 watt, since decibels are a measure of volume.

    Which is easier to upgrade - cabs or head? Hard to say. You can double your head's power and add 3 db to your volume. You can upgrade your cab to a more efficient one and you may gain more than 3 db with the same input power. A balance of both is a happy place.

    My experience is that although many bass players like heads in the 400-watt and higher range, they really don't use that power because they don't have to push them very hard to get the volume they need. This is OK, as it means that if they have to push the amp really hard for a highly percussive passage, there is reserve power (also called "headroom"). But it's power that's seldom used.

    I hope this helps. it doesn't provide answers, but it may help you evaluate your current system more accurately and help you decide where to spend money.
  7. Now, That is showing nothing but pure LOVE!

    Nothing more to say.




    Jul 16, 2012
    This is the only specs I can locate for the 4x10:
    Ohms: 8 ohms Impedence
    Speakers: 4-10" FenderĀ® Special Design EminenceĀ® 8 ohm, 87.5 watt Speakers, P/N 0068843000,
    1 Compression Driver High Frequency Horn P/N 0048847000
    Features: Attenuator on Horn, Dual, Parallel Wired, 1/4" Jacks, Perforated Metal Speaker Grille, Heavy Duty Spring Loaded Handles, Controls: Horn Attenuator (Rear Panel)

    And this is what I could find on the 1x15:
    Covering: Black Carpet with Black Metal Grille
    Weight: 54 lb. (25 kg)
    Dimensions: Height: 20.75" (52.3 cm),
    Width: 23" (58.4 cm),
    Depth: 14.5" (36.83 cm)
    Power Handling: 500 Watts (Program), 250 Watts (Continuous) Handling Capability

    So not much and not what you were wanting. Sorry. Also let me apologize for me assuming you were being hateful.

    What you're saying is that with my current set up, I wouldn't be gaining much if I went to the Acoustic B600H head, correct? Just around 3dbs?


    Jul 16, 2012
    Solarman. you one funny guy dude! Just had to say that. :)
  10. Pilgrim

    Pilgrim Supporting Member

    Not every manufacturer publishes efficiency specs for their cabs. That sometimes is because they're not very efficient and they don't want to advertise that fact. Hard to tell in these cases, but let's just say that the more efficient speaker cabs will usually make it a point to tell you that.

    One thing that jumps out at me about the 1x15 is that it will handle 500 watts MAXIMUM for short periods (use of the term "program" is an odd one in this case) and it actually will tolerate 250 watts at steady playing volume ("continuous"). So if you had a 500W amp and played that speaker at high volumes continually, you would probably blow that speaker after a while.

    According to the Guitar Center website, that Acoustic head is rated 600 watts at 2 (TWO) ohms, not 4 ohms. Although the website doesn't list the wattage rating at 4 ohms, most amps put out slightly more than 50% as many watts at 4 ohms than at 2.

    So - if you connect your same cabs to that Acoustic head and create a 4 ohm load, my best guess is that it would be putting out about 350 watts. To get the full output of that Acoustic head, you'd have to change both cabs and buy 4 ohm cabs and connect both, creating a 2 ohm load.

    As you can see, checking the tech specs is VERY important to keep from buying something that doesn't perform as you expect it to. With your current cabs, IMO it's not a good investment to buy that specific Acoustic head. It does not achieve your objective.

    Frankly, rather than getting the Acoustic head, I think you'd realize more apparent volume by swapping the 1x15 cab for a 4x10 that matches your other cab. You would have more speaker cone area, which would move more air, which in turn would create more perceived volume.


    Jul 16, 2012
    "So if you had a 500W amp and played that speaker at high volumes continually, you would probably blow that speaker after a while. "

    I wouldn't be playing that 1x15 alone. It is being used in tandem with the 4x10. Wouldn't that distribute the wattage between the two cabs?

    I checked on the Acoustic. It shows 600W @ 2ohms, 450W @ 4 ohms and 250W @ 8 ohms.

    So if I got another 4x10 and in essence created an 8x10 cab with the same 250 watt head, it would have more volume? Thanks a lot for the info!! Very appreciated!! Glad I didn't get the Acoustic even though it seems to be a steal at $249.99 from GC with free shipping.

    One last thing and I'll leave you alone. Do you suggest playing the same "name" brands together as I'm doing now instead of mixing the names? Does it matter?
  12. Here's a suggestion. Go to the stickies. Read up on ohms and cabs. Come back here and reread your thread. :)
  13. Plucky The Bassist

    Plucky The Bassist ZOMG! I'm back from the dead!

    Jul 30, 2010
    Houston, TX
    The more cone space you have, the more efficient the dispersion tends to be, which can add up to more perceived volume. It's a good idea to keep the same cab, but at least the same speaker configuration, to reduce the likelihood of things like phase cancellation.

    I've mixed plenty before and haven't really had any issues. In some cases that are probably beyond your concerns right now, mixing a specific head with a specific cab can lend you a very unique or "classic" tone (i.e. - the Ampeg SVT and SVT810 cab)...I don't see that as a relevant issue for your current quandary though. Mix if you want, but I'd recommend keeping the cabs a matching model or brand if possible. Mixing different head and cab brands is no biggie though, plenty of people do it with great results.
  14. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    All that matters is that you like what you're hearing. Don't be so concerned with eking every little last drop of wattage out of your gear. Chances are nobody's going to let you turn up that loud on a gig anyway ;)

    But I will say that your 115 is a limiting factor in your rig, and whatever you get for a head, you need to use your 115 as a guideline. And when you plug it in, you need to use your ears to determine if you're putting your cab in jeopardy with volume. All this talk of getting full wattage out of your gear is pointless, and you're making way too much out of it. Just go play some heads and get the one you like best.


    Jul 16, 2012
    ok, I lied. Just thought of one more question. My Bassman250 head has 2 1/4 inch speaker outs on the back. I plug each of the cabs into each of the outs. Would it be beneficial or not if I were to connect them in a way that they are chained together and were just running from one of the 1/4 inch outs off the head? Am I making sense? :)


    Jul 16, 2012
    THANKS MUCH JIMMYM!! Will definitely take what you and the other experts here have suggested. You're right about nobody going to let me turn up that loud anyway. The last gig we played, our guitarist said "hey man.. you gotta turn down bro!!" ROFL! So.... I like feeling it though. Want to feel the ground rumble beneath me and that's when I know it's enough. HA!!
  17. Op- listen to what these guys have to say.
    Read the stickies,search out threads on topics you may have questions on.

    LEARN what your equiptment can or can't do!! Learn how to figure out what ohms the cabs you have are and what the total ohms will be when playing more than one cab. Also know what the minimum load you amplifier can take. It can make the difference of running trouble free or blowing speakers or your amplifier!

    You can learn so much by reading some of the older threads on "ohms" "cabs" or even the specific model amplifier you have.

    A 250 watt amplifier with a 410 and 115 can be very loud indeed.

    The more you know about the gear you are using, the better off you will be in obtaining the best sound you can get from that gear.

    Cheers! WG
  18. will33


    May 22, 2006

    I played that exact same rig for about a 3 hour rehearsal at a GC rehearsal space place a couple months ago and came away thinking the cab was a one-note-wonder but the amp was something pretty nice when I played it through other speakers.

    Shows how different folks ears are. Use yours, they know what you like best.

    +1 to the folks here, they giving good help.
  19. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    No benefit to that at all. Those are just in and out jacks for daisy chaining up one cab to another. Just plug one cord into each speaker.

    Anyway, if you're already too loud, just use the amp you have if you like the sound of it. There was a time when 250w was considered earsplitting, and they'd put warnings about hearing damage on amps that had that much wattage.
  20. christw

    christw Get low!

    May 11, 2008
    Dayton OH
    I agree with the advice given in this thread.

    GENRLEE, I can relate to your want for more volume, but how often are you going to use it? In my experience, that's not too often. If your current rig meets your needs, why not let it do just that? ;)

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