Full Range Box as Sub

[Dane Boulton]

Hi Guys. I'm running. a temporary PA with two 10inch cabinets a side and I'm looking to add some more bass response. I have a very limited time frame and budget and I'm wondering if I can use two 15inch cabinets with all the HF rolled of on a GEQ as a set of subs. I don't want to use it for the HF as the 10inch boxes are off a superior quality. Will this work at all? How will it sound?

 

[FMEng]

A graphic EQ won't provide enough attenuation of the highs. You need a true low-pass filter. Besides, a 15" woofer in a two-way box typically is not tuned to go that much lower than the 10"

 

[Thetechmanmac]

You won't get as low as if you were using a dedicated sub, but if you are using an amp and it has crossover capabilities try to use that.

 

[Dane Boulton]

Okay. I have a low pass filter no problem. I'm interested to give this a try. I just want to see how much more low end volume I can get.

Thanks for your input guys

 

[techieman33]

Only way to find out is to try it, don't expect to get tons of low end though.

 

[jkowtko]

Okay. I have a low pass filter no problem. I'm interested to give this a try. I just want to see how much more low end volume I can get.

Thanks for your input guys

My guess is that you will get as much bass as if you used the 15" cabinets as your mains.

Just make sure they aren't out of phase with your real mains, otherwise you may cancel out some of the bass. Test the polarity reverse if you have one.

 

[JD]

The problem with standard speakers as subs is that the voice coils are not overhung, so on long excursion most of the coil is outside the gap and only functioning as a resistor. Thus, super low efficiency. Subs use overhung voice coils and as a result their general efficiency is not as high (that and the heavy cone) but more usable voice coil remains in the gap during heavy excursion so they end up being more efficient when cranked and pumping. In a pinch, full range cabs will work, but I would disconnect the horn if possible.

As you can see by the picture, there is a trade-off between having a high efficiency speaker, and having it remain efficient at very low and loud frequencies.
Here's a neat article about subs : http://sound.westhost.com/subcon.htm

 

[avare]

Hi Guys. I'm running. a temporary PA with two 10inch cabinets a side and I'm looking to add some more bass response. I have a very limited time frame and budget and I'm wondering if I can use two 15inch cabinets with all the HF rolled of on a GEQ as a set of subs. I don't want to use it for the HF as the 10inch boxes are off a superior quality. Will this work at all? How will it sound?

What models? That makes a world of difference.

Andre