Bass amp instead of subwoofer with helix

[bendagostino8]

So for a while now I've been playing my guitar into my helix into two powered pa speakers and a small subwoofer. Unfortunately the subwoofer broke and my overall tone isn't as great without it. What I was wondering is if I send the output of my second pa speaker to a bass combo amp instead of a subwoofer would that sound decent?

[tomgaydos]

PA mains plugged into a bass amp will not sound nearly as good as with a subwoofer. Both the mains and the bass amp are going to be reproducing all of the frequencies and it'll be muddy. Replace the sub or get a 15" combo. 

I play through a PA with 2 QSC K8 mains and a KSub 212 and it easily handles a low B. Depending on what your mains are, I'd probably just replace or fix the sub.

[waymda]

It really depends on the bass combo, how you set it up and how much volume you need. Why not just try it?

 

I'm assuming the send is not powered - that'll blow the amp.

[DunedinDragon]

It's not going to have the same low frequency cutoff as a sub.  It will just reproduce the entire signal it receives so who knows if it will work for you outside of trying it.  Generally speaking guitars have very little representation at the the frequencies isolated to a subwoofer.  That's mostly for frequencies below 125 hz which is the low bass strings and kick drums, toms, etc.

[datacommando]

On 5/1/2024 at 1:10 AM, bendagostino8 said:

So for a while now I've been playing my guitar into my helix into two powered pa speakers and a small subwoofer. Unfortunately the subwoofer broke and my overall tone isn't as great without it. What I was wondering is if I send the output of my second pa speaker to a bass combo amp instead of a subwoofer would that sound decent?

Hi,

I would think that if you were using a system that employed a sub woofer then it must have been controlled by a crossover. There are some crossovers that use 80Hz as a standard, but others may be 150Hz. It is an area of much debate. Do you know at what frequencies the sub should be working on?
 

Also, as you said that this rig was a powered PA system I think you would be better off replacing the defective sub, as the whole thing was probably designed to work in unison and come close to a full range system. 
 

You didn’t mention the scenario in which you are using this set up? If it’s for gigging, and making a living, it may be time for an update on your PA system.

 

For reference, here are the frequencies for guitar in E Standard:

• 82.41 Hz Low E (6th string)
• 110.00 Hz A (5th string)
• 146.83 Hz D (4th string)
• 196.00 Hz G (3rd string)
• 246.94 Hz B (2nd string)
• 329.63 Hz High E (1st string)

Here are the basic range of frequencies for a bass guitar.

• 41.203 Hz E
• 55.00 Hz A
• 73.416 Hz D
• 97.999 Hz G

Hope this helps/makes sense.

[Schmalle]

To use a bass amp as a subwoofer you could split the signal for the bass amp (low frequencies) and the PA speakers (everything above low frequencies) using the split block in Crossover mode with a frequency around 80...180Hz. Main L/R for the PA speakers and a Send for the bass amp.

[DunedinDragon]

On 5/1/2024 at 7:49 AM, Schmalle said:

To use a bass amp as a subwoofer you could split the signal for the bass amp (low frequencies) and the PA speakers (everything above low frequencies) using the split block in Crossover mode with a frequency around 80...180Hz. Main L/R for the PA speakers and a Send for the bass amp.

Depending on what type of sub he was using it may not be a simple forward facing speaker like an amp.  Usually there some form of baffle or venting that allows the low frequencies to do what they do best and permeate in a 180 degree fashion as well as helping accentuate the lowest frequencies, so just boosting the low frequencies through a simple speaker might not have the same effect he was getting with his other subs.  But who knows, it may be enough if it's just guitar anyway.

[DunedinDragon]

On 5/1/2024 at 7:18 AM, datacommando said:

I would think that if you were using a system that employed a sub woofer then it must have been controlled by a crossover. There are some crossovers that use 80Hz as a standard, but others may be 150Hz. It is an area of much debate. Do you know at what frequencies the sub should be working on?

I'm not sure about the studio subs as I don't use them, but most live subs these days allow you to adjust the cutoff frequency to accommodate what's best for your mains.  Or in some cases the mains allow you to limit the frequencies coming from the sub to match their preferred ranges.