Extension cab question/s...

[Eatapeach1965]

I’m sure I may have not understood correctly,but...

I want to add an extension cab to my Fender Rumble 500 2x10 combo.

Initially, I wanted to do a 15”, but then read some where there can be issues when the cans aren’t matched- speaker wise.
I really want to have the 15 compliment the 2x10’s. Though another 2x10 would push a little more air and still stay punchy.
I was under the impression it’s a common thing to do.

Thanks.

 

[Old Garage-Bander]

As was more the case in the old daze, diameter by itself no longer determines how a driver will sound.
There are tens in the right cab can go lower than 15s.
15s in the right cab can provide all the punch you need.
The key being "in the right cab."

There is no guarantee that just adding a 15 will compliment a pair of tens.
It can, but it's trial and error for the most part.

Hopefully some folks who have paired up a 15 (Rumble I assume) with a Rumble 500 combo will come by and comment on their experience. I know there is a lot of love for stacking a Rumble Rumble 2x10 cabs.

 

[Wasnex]

I’m sure I may have not understood correctly,but...

I want to add an extension cab to my Fender Rumble 500 2x10 combo.

Initially, I wanted to do a 15”, but then read some where there can be issues when the cans aren’t matched- speaker wise.
I really want to have the 15 compliment the 2x10’s. Though another 2x10 would push a little more air and still stay punchy.
I was under the impression it’s a common thing to do.

Thanks.

Mixing dissimilar cabinets is common but it may not provide optimal results unless the cabinets are designed to work together. If the two cabinets have significantly different phase or group delay characteristics you end up with uneven frequency response and shifting polar patterns. Phase and group delay variances can occur between two dissimilar designs with the same size drivers as well as two designs with different size drivers.

You also have to be concerned with each cabinets efficiency, power handling, and impedance. If you pair an 8 ohm 410 with an 8 ohm 15 and drive the cabinets with 400 watts total, the 15 will get 200 watts and each of the 10s will get 50 watts. If the 410 has an efficiency of 103 db/1 watt and the 15 has an efficiency of 95 db/1 watt, the 15 is not going to contribute much. If the 410 is a 4 ohm cabinet you get a little more even distribution of power between the individual drivers. Each 10 will get 100 watts and the 15 will get 200 watts. Unfortunately this will further increase the volume difference between the 410 and 15.

IMHO, It fine to mix and match. Just make sure the pairing sounds good and you are not exceeding the power limits of one of the cabs.

 

[BassmanPaul]

You have to make sure that the cabinets you use are wired with the same polarity. If not they’ll fight all night long.

 

[Eatapeach1965]

Thanks for the replies...

I have made sure the ratings all around are within spec.

So I’m debating To pair with my Rumble 500 with the 2/10 or the 1/15....
The 2/10 would have 5” more of speaker and remain punchy...and it’ll fit perfectly under the combo. A nice uniform stack. I’m leaning that way unless I get a good deal in a 15” cab.

 

[Old Garage-Bander]

Thanks for the replies...

I have made sure the ratings all around are within spec.

So I’m debating To pair with my Rumble 500 with the 2/10 or the 1/15....
The 2/10 would have 5” more of speaker and remain punchy...and it’ll fit perfectly under the combo. A nice uniform stack. I’m leaning that way unless I get a good deal in a 15” cab.

You can't just say you have 5" more of speaker by using the linear diameter measurements.
You really need to measure or calculate the cone surface area since that is what determines how much air is potentially being moved. (All other factors being equal.)

If you disregard the depth of the cone, because we don't have that information and just go with the area of a circle, based on given speaker diameter, which is pi times the radius squared, then one ten inch speaker is 3.14 X 25 = about 78.5 sq in, times 2 speakers is about 157 sq in for both tens together. The area of a 15" circle is about 176.7 sq in.

You can see that a 1x15 will have a larger opening than the total of both tens. That's before you account for the rest of the cone surface geometry, which will likely be even larger with a 15 than it is with a 10, if the cone is deeper, thus making the single 15 surface area bigger still in comparison to the pair of tens.
Assuming my math checks out.

 

[zon6c-f]

Use your ears. If it sounds good to you it IS good