Bass -> KPA -> guitar cab => will it kill my cab?

    Hi, I was toying with the idea of getting a cheap bass to use for recording simple bass lines at home, given that the Kemper can work also for bass.
    Only problem, I normally run the KPA into a tube power amp (20W) and then into a 1x12 guitar cabinet. I am wondering if using a bass in this setup (considering that volumes will be moderate anyway, using it at home) might damage the speaker. Or the poweramp, for that matter! Provided I don't play it too loud, of course. What do you say? :)

    Quote from Laimon

    Hi, I was toying with the idea of getting a cheap bass to use for recording simple bass lines at home, given that the Kemper can work also for bass.
    Only problem, I normally run the KPA into a tube power amp (20W) and then into a 1x12 guitar cabinet. I am wondering if using a bass in this setup (considering that volumes will be moderate anyway, using it at home) might damage the speaker. Or the poweramp, for that matter! Provided I don't play it too loud, of course. What do you say? :)


    I'd just record the bass direct. (bass -> Profiler -> DAW)
    going through an extra poweramp, a (guitar!) cab and then a mic can only cause trouble.


    do you always record like that in stead of direct?

    Quote from DonPetersen

    I'd just record the bass direct. (bass -> Profiler -> DAW)
    going through an extra poweramp, a (guitar!) cab and then a mic can only cause trouble.


    do you always record like that in stead of direct?

    No, sorry, I probably was a bit misleading in the first post: sure, I would want a bass for recording purposed, but then I wondered if - to the end of noodling around at home - it would have been ok to hook it up to the guitar cab as I do normally with, well, guitars =P so yeah, my question ultimately didn't have anything to do with recording, that yes, I would do direct from the KPA ;)

    Might not blow it up, but running a bass guitar into a guitar cab is not a good idea. It has more to do with the frequency of sound, since the low end will move the cone in a way that it's not supposed to and could damage it. Agreed, this is a lower wattage amp than the cab, but the low end will move the cone in a way it's not supposed to. Not to mention, it will kill the character of the cabinet in the long run, even if it doesn't tear.


    At best, use it as a short term solution, but I'd strongly recommend getting a bass amp, even a cheap one, to preserve your gear.

    Quote from nightlight

    Might not blow it up, but running a bass guitar into a guitar cab is not a good idea. It has more to do with the frequency of sound, since the low end will move the cone in a way that it's not supposed to and could damage it. Agreed, this is a lower wattage amp than the cab, but the low end will move the cone in a way it's not supposed to. Not to mention, it will kill the character of the cabinet in the long run, even if it doesn't tear.


    At best, use it as a short term solution, but I'd strongly recommend getting a bass amp, even a cheap one, to preserve your gear.


    Is there a frequency warning on guitar speakers? Do not use with frequencies lower than provided by standard tuned 6-string guitars? :P
    Guitar cabinets have been used with bass guitars and synths and whatnot all the time. It's not the frequency that kills them, it's the wattage. Using a bass guitar you are more likely to continuously deliver full wattage because of the constant low frequency content. However, his amp/cab is well within safe range for that to ever be a problem.

    Quote from Laimon

    No, sorry, I probably was a bit misleading in the first post: sure, I would want a bass for recording purposed, but then I wondered if - to the end of noodling around at home - it would have been ok to hook it up to the guitar cab as I do normally with, well, guitars =P so yeah, my question ultimately didn't have anything to do with recording, that yes, I would do direct from the KPA ;)


    alrighty :)

    Quote from Trazan

    Is there a frequency warning on guitar speakers? Do not use with frequencies lower than provided by standard tuned 6-string guitars? :P
    Guitar cabinets have been used with bass guitars and synths and whatnot all the time. It's not the frequency that kills them, it's the wattage. Using a bass guitar you are more likely to continuously deliver full wattage because of the constant low frequency content. However, his amp/cab is well within safe range for that to ever be a problem.


    Thanks trazan, good to hear from someone with a direct experience on the matter :)


    When out of the know, better to be cautious!

    Compiled this information from the net, since I don't have the tech specs on the back of my hand. But this is what I was referring to.


    "Most Bass Guitar speakers have a resonant frequency between 35Hz and 65Hz. Bass speakers have longer cone travel and typically can handle the much higher power required to reproduce bass frequencies at volume levels that can keep up with a typical guitar amplifier. It will work, but you probably won't be able to get a lot of volume out of it before it starts distorting due to cone over-travel.


    Guitar speakers generally have a higher resonant frequency (Fs) and a much lower maximum linear excursion (Xmax) than a bass speaker. The Xmax for a typical guitar speaker is usually in the 0.5 - 1.0 mm whereas a typical bass speaker would be more in the 3 - 5 mm range. The resonant frequency of a guitar speaker is usually in the 70 - 100 Hz range and a bass driver is typically in the 40 - 60 Hz range. This gives the bass bass driver a significant advantage in producing low frequencies.


    The front and rear suspensions are usually different ie more flexible for bass with a linen surround, very often guitar speakers have a paper surround that will soften/fatigue with bass guitar use."


    Like I said, there isn't much danger of the cone bursting. But it will get ruined over time, because it is not designed to move forward and backward as much as it would under the pounding of low frequencies from a bass guitar. This is even more danger with a small speaker cone.

    Another informative web post:


    "One aspect of musical instrument speakers that a lot of people don't know is how they differ from hi-fi speakers.


    Hi-fi speakers are designed such that for the entire travel, the voice coil is within the magnetic field.


    Musical instrument speakers are designed so that the voice coil is past the main part of the magnetic field at the extremes of excursion. This does two things: 1) it protects the speaker from banging into the back of the magnet structure in one direction and from tearing the suspension materials in the other, and 2) it allows for largely uncontrolled current from the amp just at the edges of travel.
    Accoustically, of course, this changes the sound a t extremes of volume (whatever is extreme for that speaker). The crest of the wave is unformed, and flattened out.
    But to the topic at hand, it could be very bad for a guitar speaker/cabinet comination to be subjected to really low frequnecies at a high power (especially if the cabinet is bass reflex or open back), because there is a greater chance of overextending the speaker. It would be a lot more dangerous, but for that coil-out-of-the-magnetic-field construction I mentioned above.
    As for guitar through a bas rig, it would be hard to imagine a way for that to harm the bass speaker.
    My gueass on the main difference between bass speakers and guitar speakers would be one of voicing. Different speakers have different personalities, and I would guess (it's a guess) that MFRs take speakers with a voice for bass, and market them as bass speakers, etc."