MX51S Mini Mix 2 Four-Channel Stereo Line Mixer Black

While upgrading my gaming/AV setup, I ran into various audio issues that, after many purchases, tests, returns, and cables plugged in and unplugged, eventually boiled down to me having 2 analog audio signals that needed to feed into a single analog input on my speaker system and be able to play simultaneously. Now, the cheap and dirty way to handle this is to grab a $5 headphone splitter and hook it up backwards. However, because a headphone splitter is not powered, this will attenuate the signal strength from both sources, and can even cause hardware failures if there is a spike or surge. I'm not an electrical circuits expert so I will let you research that kind of thing yourself, but the bottom line is that a powered mixer is the best way to get 2 independent signals to feed into a single input without losing strength (a switcher would be a simpler option if you don't need both sources to play audio simultaneously). This Rolls MX51S proved to be exactly what I needed: A compact powered mixer with independent volume controls, RCA output, and at least 2 RCA inputs. This mixer actually has 4 inputs, but one is XLR mono for a microphone. The mixer has a very quality construction with a powder coated metal case, solidly attached input and output jacks, and very nice potentiometer knobs with a detent at the 12:00 (gain = 1) position. The mixer actually provides a mild amplifier capability if you turn the knobs past 12:00, but some people report clipping at max gain. This is hardly a drawback, as a unit this small with mixing capabilities really isn't meant to be used as a serious amp. I just set my overall system volume loud enough that a gain of 1 is more than I will ever need, and I keep the input volumes turned down. The mixer works excellently. I can play both sources at the same time with fully independent volume control, something that I didn't have in my system prior to my upgrades, so even though I hadn't originally planned to use a mixer with my setup, I am very glad that it eventually became necessary, because I now have much greater versatility. The mixer is very compact and fits nicely off to the side in one of the shelves of my AV cabinet. Many other mixers are much larger and although they probably work well too, I don't have the space or need for that kind of thing. I did run into one interesting issue while using this mixer. Both sources that I have fed into it are analog signals from DAC's. I went through 5 different DAC's before getting a setup that actually worked correctly all the time. One of them, an Insignia purchased from Best Buy, started causing loud popping and clicking to come out of my speakers after the optical source was turned off...but only when it was connected to this mixer. If I plugged it directly into my sound system, bypassing/disconnecting the mixer, it was fine. HOWEVER, with the DAC's I eventually settled on (one a FiiO D3 and one an eSYNiC), this problem does not occur at all, so I'm guessing that some combination of poor grounding and signal interference created a "perfect storm" between the Insignia and the Rolls mixer. In any case, the issue no longer occurs, and I don't think the mixer is to blame at all. Overall, I am very impressed and pleased with the mixer. It does exactly what I need, does it very well, and all for a bargain price.

If you're looking for a quality, compact stereo mixer to combine multiple audio sources and output to a single pair of headphones or speakers, this device works perfectly. Measuring roughly 5 inches by 3 inches, its construction is solid and surprisingly made in the USA. All of the ports feature a nice and tight fit and the knobs are silky smooth. It's powered by a power adapter which is included. It has four separate channel inputs and two output options. Channel 1 is an XLR input with phantom power option (which you can turn on/off). Channel 2 input is via RCA or 3.5mm. Channels 3 and 4's input are RCA. Output is via RCA or 3.5mm. There are more than enough ways you can set this up depending on your devices and needs. If you need to use 3.5mm, either as an input or output, you can simply buy a 3.5mm to RCA cable adapter. Some reviews complain about static, hissing, or lowered volume; I have not encountered any of these issues under normal use. As long as you are using quality cables and your source output devices aren't cheap, no audio issues should be encountered. I can easily control each channel's volume independently with no loss in audio quality. Turning the knob all the way down will completely mute the source and turning it up has more than ample volume (although this may vary a bit depending on the quality of your output device). The only actual hissing I can hear (using headphones) is when you get near max volume on the knob when all other channels are silent. At the volumes you encounter the hissing at, you would blow your eardrums out. Under normal use, you don't hear it at all. There are obviously several ways you can hook this up. For reference, I am using it to connect the audio from my PC and the audio from my game consoles (PS4 and Switch) and have it all output to my headphones. In my case, the game consoles are hooked up to a Denon A/V receiver and I am using the headphone output from it to connect to the stereo mixer. For the PC audio, I am simply using the front 3.5mm output and have it connected to the stereo mixer. From the stereo mixer, I have the output audio plug into an external headphone amplifier which then finally outputs it to my headphones. My headphone amplifier definitely helps with overall volume, but even without it, the stereo mixer has plenty of power to output enough volume even to my higher ohm headphones from Sennheiser and AKG. Even hitting about halfway on the knob gets too loud and about a quarter of the way is good enough for normal use. With this particular setup, I can now get game sounds and if needed, I can stream music from my PC at the same time. Or I can use voice chat on the PC instead of using Playstation's party chat or the Nintendo Switch's currently horrible (non-existent) chat system. And of course if I just want one audio source, then I can simply turn down the knob on the stereo mixer to mute it completely. All in all, this is an excellent compact stereo mixer which makes life easier if you have a setup requiring multiple audio sources outputting to a single headphone/speaker setup at the same time. It works well as somewhat of an audio switcher as well without actually having to switch inputs or cables around. If this sounds like what you need, I wouldn't hesitate to recommend this product.

I was setting up a small PA system for a fellowship hall area in our church and I wanted to combine the line inputs from the cordless microphone receiver and the audio from a television. This mixer is exactly what I needed to join these two signals into a single input on the amplifier. Previously the microphone signal went to the RCA inputs of one amplifier input while the TV audio went into the RCA inputs of a different amplifier input. Only one or the other could be input at a time, so a presenter who had a video with sound to show on the TV (through the HDMI TV input) had to switch the amplifier input from the microphone to the TV to show the video with sound through the PA into the room. Now they can start and stop the video without switching and can even add their own comments with the microphones while the video is showing. Among the possibilities is that we can have Karaoke in the room which several people are thinking about. The mixer is solidly built and it was easy to set the two volume levels for our inputs. The mixer operates very cleanly without noise when adjusting the volume levels. I appreciate that there are still two inputs available after using the RCA inputs on channel 3 & 4 for the microphone and TV audio. Channel 2 has either RCA input or 1/8" stereo input, so it is a logical choice to use for an iPod input at some point. Channel 1 only has an XLR input with switchable phantom power so we could use that for a wired microphone at some time if we want. It would be a very useful input for a DJ arrangement (maybe for a Karaoke night?) although we aren't using it at this time.

Update: So after owning this for four years, a while back I figured out the source of the buzzing noise I referred to in my initial review. Turns out, if your sources are set to different volumes it causes this feedback. The buzzing is faint but it's like nails on a chalkboard to me. It's frustrating that the very point of having this mixer is to manually adjust the volume of different sources on the fly to their varying needs, but when they don't line up there's distortion? It kind of defeats the point of having the mixer. Maybe mine is defective, but who knows? Let me start this by saying it's a fantastic unit for its size (super compact). I use this with my computer desk which I have 3 inputs I want to blend: PC, Mac, and Game Consoles. It does mostly what I want it to with the exception of a few things: The first channel (the most powerful one) is dedicated to a mic, I think it would have been nice if the aux input shared this channel rather than the 2nd channel in case you don't use a mic with your setup. There is a noticeable buzz when I get to 1/5 volume on the input with my PC. I thought it might just be that channel but I switched my PC to other sources and the problem persisted. I've tried all kinds of combinations of lowering my pc volume to cranking the volume as high as possible on my PC and the problem persists. It's really odd that this is only a problem on my PC and not on my Mac or any other input. I don't have this problem when I directly connect to my speakers (bypassing the mixer) from my PC. The previous problem is even worse on the front-mounted headphone/aux jack. The buzz from my PC is so bad that I have a hard time using it. My last gripe is that there is no master volume nob. It would be nice to adjust all sources on the fly. I spent a lot of time on the bad but I do want to stress this is a great compact unit. For many, this might be the perfect solution. While it is a great product, I'm left wondering if I spent a bit for money on a nicer mixer if I would have had any of my issues.

I've never written an Amazon review, however I must say this is the best piece of tech I have ever purchased. My most annoying dilemma was playing my Xbox while listening to podcasts and discord on my PC, but I always had to have an earbud underneath my headphone... No longer. This device is perfect to hook up your Xbox and PC and have it come right to a single pair of headphones with separate volume controls for each source. Absolutely no static or anything coming from the device. 10/10, works EXACTLY how it was expected. NOTE: Remember that you must convert all audio signals to RCA outputs if you desire to use this mixer properly. Which means if you intend on using this with a PC, you will need a 3.5mm jack to RCA, and if you want it from your Xbox, you'll need an Optical to RCA converter, which is not a cable... All in all, though, it is difficult to find a mixer that allows for stereo audio, while not being an over-the-top piece of hardware.

It isn't always that I am this happy about an improvement to my technological set-up. First off, I will list my situation and how this solved it. I live in a military barracks, so I only have one room. This means, I can only have one speaker set, and as an avid gamer I need many connections to that one speaker set. I was originally just using a simple splitter, but, suddenly, I needed an input control device between my inputs and my speaker when I introduced a nintendo switch into my gaming console collection. The switch, sadly to say, is completely unreliable soundwise without some sort of an amplifier inbetween it and the speakers. Therefore, I decided to take a leap of faith and hope that I would be able to amplify the sound of the switch using the dials on this device, which was the main reason I bought this unit. In that regard, it worked absolutely wonderfully, although if anyone reads this review and decides this will work for their setup, I must warn that you should also buy the kript ground isolator as well as the switch has a terrible feedback loop. I was able to aux from the switch to the kript GI to an RCA cable (Switch>3.5mm Aux cable>Kript GI>RCA connector>mixer) to this line mixer and the sound is absolutely phenomenal. I will mention that you should be very careful when considering the device, as the 4 knobs only work for 3 RCA inputs and 1 XLR input. If you are not using an XLR capable input, you will get nothing out of the fourth knob (technically the first). In this regard, I speculate the device is mostly intended as a very portable line mixer for taking to music gigs and attaching all of your instruments to the same amp/speaker set. However, as noted above, this works absolutely perfectly for my set-up and was well worth the money.

This is a great little mixer. I'm using 2 of them in conjunction with Amazon Eco Dot units in my office and bedroom. In both of these cases, the Dot is plugged into stereo input 4 while the source (XM radio in the office, TV in the bedroom) is plugged into stereo input 3. This lets me vary the volume of the entertainment source while leaving the Echo at a constant volume so I can hear responses to questions regardless of the volume level for the other source. The mixer is extremely sturdy and well constructed and runs cool to the touch even though I leave it on continuously. It was simple to set up and operate, there's plenty of room on the top panel to label the input knobs (using my P-Touch label maker) and it is very quiet. While I didn't use measurement instruments, I can not detect any added noise, hiss, or other interference, and the dynamic range appears to be unaffected - no clipping or distortion is audible. The only oddity is that all of the input knobs have detents just to the right of the 12 o clock position (almost straight up). This makes it easy to match the level of two inputs in that position but seems kind of arbitrary to me. Also, the default for phantom power is on; while I haven't plugged a microphone into the unit, this seems like a risky setting. If a dynamic microphone is plugged into this input and there are any shielding issues with the cable, you'll likely hear crackling noises as the microphone is moved around and the cable flexes. Moving the jumper to the off position should solve the problem. All in all, this is a great little mixer. Solid, quiet, great build quality, and reasonably priced. I own 2 of them now and would not hesitate to buy more.

This thing performs very well. Granted, I just came from a "rolls MX44S Mini Mix IV 1/4 and 1/8 Mixer" (which I returned), and that thing sucked. This unit does what the last unit did not: it works. There isn't any big distortion or noise when mixing two channels. I can turn the volume up pretty high with no discernible distortion. I have not yet tested mixing 3 or 4 channels together, but two works well so far. The only reason I didn't give this device five stars is one quirk: when the two channels you are mixing are not set to the exact same volume level, a small amount of noise/hissing is introduced. I don't think this is super noticable when there is actual sound being played by one of the signals, but when the inputs are silent, the hissing is noticeable. When they are set to the same volume, there is no noise and it is perfectly silent. This is independent of the actual volume level you are using - they just need to be at the same level. This doesn't affect my usage, since I keep them at the same volume level. I will do some more testing and possibly update this review.