Modding a Rumble 25 combo..

[moogieotter]

Um. A Fender Rumble broke?

 

[BassBeginer64]

MCM 55-2960
20 bucks
8"
92 dB (meh)
80 watt (160 peak)
Fs 68; frq resp 48-6k (+/- ?dB)
Ive used these, pretty dang thumpy and full range.
/QUOTE]
Hell of a good price and decent specs
Link Removed

 

[AstroSonic]

I know this is an older post but I was searching for speaker upgrades for Rumble 25 which led me to this post. I'm a tinkerer at best, don't know anything about cab size vs. speaker size, ported vs sealed, xmax, cab tuning, etc but I can put a speaker in. I took a chance and went with the Alpha 8A. It didn't sound good at all. It moves a LOT of air out of the port. So much you can hear it. It sounds like when you purse your lips and blow hard. And it's loud. I don't think that's a good speaker for this cab unless I'm doing something wrong. Has anyone tried the Dayton or Alpha 8A with different results? I may try the Dayton...

Others have used the Alpha 8a in the rumble 25 and liked it. Your result suggests that you used the stock tuning: the result is a grossly misaligned cab and poor tone. Most any worthwhile upgrade will require retuning: changing the resonant frequency of the cab by changing the port tubes. You will probably have to get new tubes - just buy some pvc pipe. You'll want to try a modest range of tunings to get the tone you like the most - port lengths of 4-6 inches.

In the meantime you have a decent driver installed. Consider 1) using the cab sealed by stuffing wash rags into the ports, and 2) tuning lower by plugging one of the ports (wash rag). Either of these requires no mod of the cab.

The Dayton also will work quite well with the cab retuned.

 

[Claymore]

You need a driver with more excursion capability (Xmax). The Dayton PA255-8 will perform well in the Rumble 25's 0.8 cf cab, tuned between 50 and 60 Hz. For two 2-inch diameter ports, the length will range from about 4 to 6 inches. There will be low to moderate, mid to upper bass peaking - enough to add some bass richness, but not enough to cause soft, pillowy bass and poor note definition. You should install some acoustic lining, as Linnin suggested. This will add 4 to 5 lbs to the weight, but is still quite reasonable. Relative to the stock Rumble 25, you will get deeper, more articulate bass, smoother mids (due mainly to the acoustic lining), and higher volume (due to greater sensitivity of the Dayton driver).

I realize this thread is ancient but I just bought a Rumble 25 and purchased the Dayton to go with it. Will be tuning it as you suggested but I am new to acoustic lining... Do you have any suggestions or a link to share that would point me in the right direction? I just want to purchase the correct kind of lining. Thanks in advance.