The speaker is often the most overlooked part of the signal chain. Unfortunately, that means it’s also the weakest point in most signal chains. This is true especially in the lower end of the amp market. Now, I’ll be the first to admit my own ignorance on just how a magnet, a voice coil, and a paper cone can yield such a drastic aural smorgasbord of options, but the market is flooded with speakers of all sizes and tonal options.
For almost any shortcomings of a stock amp, a change in speaker can often breathe new life into it. In my experience as self-appointed champion of cheap-o amps, I often find stock speakers to be brittle in the high end and lacking in the mid and low range. Once again, I’m not privy to the mechanics of why and how, but that’s how my ears perceive almost every low-budget stock speaker I’ve strummed an E chord through. From a business perspective, I get why amp manufacturers do this, that’s part of getting these amps at their price point to get tools to budding guitarists on a budget. Cheaper speakers also weight less, which cuts down on the freight costs. I get it, I don’t like it, but I get it.
Now for the utility of swapping speakers. The most obvious reason is if an amp sounds too bright, you put in a darker sounding speaker (or the opposite if an amp is dark and muddy sounding). For example, I have a little Crate Palomino V8. It is 5-watts, has a10-inch speaker, it’s EL-84 driven, and almost pure upper mid-range. The stock speaker just had a shrill high end to it, it was downright painful to hear. Instead of giving up on that amp, I threw an Eminence Rajin’ Cajun in it. This speaker is more of an “American” voiced speaker, aka, more low-end, less mid-range, and a smooth high-end. This really balanced the amp out and turned it into one of my go-to amps for low-wattage debauchery.
Speakers can also be used to increase or decrease the volume and headroom of an amp. Speakers have what’s called a sensitivity rating, which, to my best troglodyte comprehension, means how efficiently the speaker converts the wattage it’s being fed into decibel volume. Now, let’s combine this with the way that wattage works with decibels (every time you double the wattage, it increases the volume by 3 decibels). In theory, if your 20-watt amp just isn’t keeping up with that Captain Caveman impersonator you call a drummer, a more efficient speaker can increase the volume in the same way a more powerful amp would into the same speaker. Most cheap stock speakers I’ve experienced have a sensitivity of around 97db. If you swap in a speaker that has a sensitivity of 100db, that will effectively give you the volume of a 40-watt amp. Some speakers even go up to a 103db sensitivity, which would effectively give you the volume of an 80-watt amp. Conversely, if your 80-watt amp is going into a 103db speaker, then a 100db speaker would make it effectively as loud as a 40 watt amp and a 97db speaker would be as loud as a 20 watt amp.
Real life example: I had a Vox AC-15 that just needed to have its tubes cooking to get that sweet spot of compression and breakup. I know 15 tube watts don’t sound like much, but when you have a bar owner telling you their bartenders can’t hear peoples’ drink orders over your precious little riffs, you’d be surprised how loud an AC-15 can get. I took a gamble on a Heppner speaker, which was actually a speaker from an old Hammond organ, plus I scored it on eBay for only $20, AND it’s an alnico magnet! These old speakers were very “inefficient,” which meant a lower volume. If I remember correctly, the sensitivity difference between the stock Warfdale speaker and the Heppner was 97db to 94db. This effectively made it as loud as a 7.5-watt amp, plus the speaker broke up just as smooth as silk. This simple speaker swapping allowed me to let the amp hit its sweet spot on the power amp distortion while appeasing the bar owners’ desire to sell drinks and compensate me for entertaining their patrons.
Opposite real life example: I don’t have any 100-Watt half stacks. It’s just not practical at all for a weekend warrior playing in dive bars. It’s very rare that we play a show where I’m not mic’ing the guitar amps, so I really don’t need a deafening loud amp very often. BUT, for those rare shows that require huge sound without the investment of a half-stack, I enlisted the help of some vintage solid state Peavey with a mid-80’s Bandit 65. Those old Peavey’s are built like tanks and just miles of clean headroom for pedals. The stock Scorpion speaker was a little brittle sounding on the high end, so I knew I wanted to replace it. When researching a suitable replacement, I settled on the Eminence Swamp Thang, which is a heavy duty speaker with power handling for days and a sensitivity of 103db. Let’s compare this with the stock Scorpion that had a sensitivity of 97db. This speaker swap turned the amp into the effective decibel output of a 260 Watt amp! In other words, to achieve the same volume that I’m getting with the Swamp Thang, I would have to have a 260-watt amp going into the stock Scorpion. The one time I’ve been able to crank it to its full potential it started knocking pictures off the walls in my house.
In conclusion, there are more reasons to swap your speakers than “just because everyone uses a Vintage 30!” Different speakers have different tonal color variations that you can use to enhance or tame the characteristics of your amp. Speakers also have different sensitivity ratings, which can be used to increase or decrease the volume of an amp. Experimentation is the best bet here. There are so many speakers on the market, read the reviews, watch the demo videos, and get that screwdriver ready!