You all know what a guitar amplifier is. Big, intimidating stacks of speakers and dials, designed for some nice loud guitar playing. But do they work as well for other people's guitars; i.e., can a big powerful block of music-playing kit double as a home speaker for recorded music?It may seem like a stupid question, but the more I thought about it, the more I realized that speakers and amps are the same thing... kinda. And for people who don't have the money to buy a guitar amp and a home speaker, could buying the former kill two birds with one stone? I had to find out.Now, I’m not talking about a guitar amp-esque speaker made by a brand traditionally known for its amps (and before these new Bluetooth speaker things became so jolly well lucrative), such as the Marshall Stanmore IV or the Orange Box. No, I’m talking about a real power-speaker designed for guitars, with jacks and dials galore and no Bluetooth in sight.Specifically, I’m talking about my Line 6 Spider IV amp, which I have owned for at least half of my life, thus far.Now, I know Line 6 has a mixed reputation, making it an odd choice to incorporate into a home sound system. Its speakers aren't even for serious guitarists — they're for edgy 14-year-olds without much cash who just want goofy levels of distortion. In my defense, when I bought it, I was an edge 14-year-old without much cash, who just wanted goofy levels of distortion. And it still works fine for what I need.For the tech-heads among you, my Spider IV offers 75W of power. For the purposes of this article, you should know it has a 3.5mm and a 6.35mm input, and I played music from my turntable as well as some Edifier speakers (the same set-up as in my recent article about setting up a new turntable, so an Edifier M90 and Sony PS-LX310BT). The amp was getting incorporated into an existing hi-fi system, not replacing it.The other important point of context before we get started is that I had to make a conscious effort to turn off my brain before undergoing these experiments. In many parts of my rational brain, I could tell that a guitar amp wouldn't function smoothly as a speaker; they're not designed to hit a wide range of frequencies, just the ones guitars play at, and they're not intended to be connected to a chain of other players. If I switched off the scientific part of my cranium, I could just mess around with wires, have some fun, and see what happened.Turning my amp into a subwoofer(Image credit: Future)With my first experiment, I decided to start small: I’d see if my amp could function as a subwoofer for my Edifier M90s. I wanted to use its wattage just to give me some extra 'oomph', even though it’s not a bass amp.First, I used a 3.5mm to 3.5mm cable to connect the M90s, from their Sub Out port, to the amp’s smaller input… and nothing happened. I couldn’t hear a peep from the Line 6, though oddly, the amp’s volume control adjusted the output from the speakers.Next, I took the risky move of using a 3.5mm to 6.35mm to connect the Sub Out port to the amp’s primary input — risky because I was using an unbalanced stereo cable across devices really not meant for this use, and I wasn’t sure what was going to happen.I turned the Line 6’s dials all the way down, plugged the cable in, and popped on some Morgan Wallen before slowly turning the volume up.The resulting speaker sound is best described as ‘rhythmic, distorted pulses’: I was getting something, but it sounded more like asthmatic coughs than music. The amp was clearly connected, and outputting something, but it was just rhythmic fuzz. I suppose that's the Line 6 effect.I spent quite a while fiddling with the dials, but it was impossible to reduce the drive, while also retaining enough volume for the amp to be audible when I wasn’t putting my ear to it. So it wasn't good for most music, but turn the volume up while listening to a rock track, and the pulses sounded like the strums of a really keen rhythm guitarist trying to play along. This was pretty nostalgic for me, because when I bought the Line 6, that's basically exactly what I was doing.I tried the same experiment with my turntable, which was connected to the Edifiers via Bluetooth, and found the same result, albeit watered-down. How about as a giant aux speaker?(Image credit: Future)Perhaps I was trying to run before I could walk? For my next experiment, I decided to make things a bit more simple. I connected the iPad I was using as a music player, to a USB-C to 3.5mm converter, and then plugged in the aforementioned 3.5mm to 6.35mm cable which led to the guitar amp’s primary input.I could hear music! I mean, if you could call it that. The Line 6 not being a bass amp became patently clear here, because I was basically just getting treble. It was surreal; I've tested speakers and earbuds with barely any bass, but never any with literally no low frequencies to speak of. Plus, a weird phase effect was causing noticeable oscillations in the music, providing a powerful attack but fast fade. It was most audible in Post Malone’s voice (I’d moved on to Post Malone at this point) – it sounded like he’d learnt Mongolian Throat Singing.The resulting sound was odd, and didn't match even the affordable Tribit Stormbox Micro 3 I use in the shower, but at least the guitar amp gave me some control over it: I could use the dials to add a bit of warmth, and some fuzz to mask the lack of bass.Then I had a brainwave: I returned to the 3.5mm to 3.5mm cable from the first section, and music sounded much better. There was finally some bass (not much), and Malone was back to his regular singing voice. It was the closest to a speaker I'd managed to bring the amp.It wasn’t perfect, though: Line 6 amps can sound quite tinny, and I felt like I was listening to music on some cheap earbuds you get free with a flight… just 75W ones that'd annoy the downstairs neighbor.Let's add some drive(Image credit: Future)Obviously, the thing missing from my set-up was more things, so I whacked out a Pigtronix Fat Drive to add to the mix. You can probably tell what this does; it’s obviously a vital addition to an amp which is slated for offering nothing but drive.Here’s how the set-up looked now: a USB-C to 3.5mm converter plugged into my iPad, leading to a 3.5mm to 6.35mm cable, which was plugged into the Fat Drive pedal, which was connected to another 6.35mm to 6.35mm cable, which led into my amp. That music was getting quite a few air miles before being played. You can probably imagine what more drive did to already-too-distorted music; it sounded like it was playing from behind a waterfall. Add to that the phase effect that playing music from the 6.35mm port provided, and it was even more of a write-off than before.I wasn't expecting sudden audio clarity, though. As with the rest of this piece, it was just a fun experiment to try.Unfortunately, there was a casualty to this experiment: my Fat Drive pedal conked out the day after the test, and I’ve not been able to revive it. I don’t blame my tests, as much as the several years of misuse and poor management prior to them, but I’d still like to pour one out for the Pigtronix.Lessons learnt(Image credit: Future)Obviously, I didn’t go into this experiment thinking that a guitar amplifier would make for a genuine home speaker alternative. That’s like thinking a pottery kiln is a good microwave replacement; it technically does the same thing, but things are going to get a little crunchy.But I was hoping it'd turn into a fun, albeit messy, party speaker in a pinch, in case I had people over and suddenly wanted room-filling sound. Sure, I could buy such a device, but given how expensive tech is (and how much space that'd take if I already own an amp), who needs that?I always knew, too, that some useful features would be missing. My amp doesn't allow for a wireless connection, for example, and it's far from being portable.The solution is already out there: recent Bluetooth speakers released under the Fender name (though made by by a different company called Riffsound) had an XLR port that doubles as a 6.35mm jack, so you can plug a guitar and use it as an amp, even though it's technically a speaker.Given how many guitar companies now make consumer tech (Marshall, Fender, Orange; Yamaha does too but it's an everything-music company really), it'd be great to see this kind of feature again. Or, at the very least, some way of blurring the borders between amp and speaker. Not all of us have the space or money for both.