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We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
If you want a simple, bulletproof way to send one mixer or interface output to two pairs of DJ studio headphones, choose Rockville RC1DTRS; if you need a compact all-in-one kit that changes your voice and feeds audio into a headset while you stream or game, choose DIANMO A9. I'll be upfront: these two aren't really competitors in the usual sense, and I'll explain that below. But since shoppers keep landing on both when they search for DJ studio headphones and end up torn, I'll treat the question honestly — including the fact that neither one is a set of headphones for exercise, and neither is meant to be.
• Rockville RC1DTRS biggest strength: a purpose-built 1/4" TRS splitter — one male TRS plug into two female TRS outputs, 100% copper conductors, 90% OFC spiral shielding, 26 AWG, 1 ft long.
• Rockville RC1DTRS biggest trade-off: it makes no sound on its own. No drivers, no battery, no voice effects — it's a passive cable, nothing more.
• DIANMO A9 biggest strength: a palm-sized (1.97in x 1.97in, 39 g) voice changer and sound card kit with 7 voice modes, 3 sound modes, a color screen, and a full accessory bundle including headphones and adapters.
• DIANMO A9 biggest trade-off: it's a creative/streaming gadget, not studio monitoring gear. Its audio path is 3.5mm auxiliary and USB, not balanced 1/4" TRS.
• Who each pick is for: Rockville RC1DTRS for the DJ or studio user who needs to split a cue signal to two headsets; DIANMO A9 for the streamer, gamer or content creator who wants voice effects and plug-and-play device switching.
Let's be clear about what this thing is. The Rockville RC1DTRS is a 1-foot splitter cable: a single 1/4" TRS male plug on one end, two 1/4" TRS female jacks on the other. That's the whole product. The value is in how it's built — 100% copper conductors for signal clarity, a 90% OFC spiral shield to reject EMI and RFI, 26 AWG gauge, and a rugged PVC jacket in black with a round profile. Plug-and-play, no power, no setup.
In a DJ context, this is the cable that lets two people monitor the same cue output. One 1/4" feed from a mixer or audio interface goes in, two pairs of DJ studio headphones come out. That's genuinely useful for back-to-back sets, for a producer and an artist sharing a monitoring chain, or for a small studio where you want a second set of ears on the same mix without buying another interface. The snug-fit connectors and the shielding matter here: in a booth or a rack full of gear, RF noise and cable flex are real, and a loose splitter is a quick way to get hum or dropouts.
Who should buy it: anyone with 1/4" TRS gear — mixers, audio interfaces, headphone amps — who needs to duplicate that signal to two outputs. The brand lists compatibility with common interface names and a wide range of 1/4" TRS devices, plus phones and several Amazon Fire tablet generations on the compatible-devices list, though the practical use case is pro audio, not tablets.
Who should skip it: anyone expecting it to be headphones, or to add features. It doesn't amplify, it doesn't convert formats, and it won't turn a 3.5mm jack into a 1/4" one. If your gear is all 3.5mm, this is the wrong cable.
The DIANMO A9 is a completely different animal, and honestly the more interesting product of the two if you're a creator. It's a voice changer and sound card kit built around a tiny square unit — 1.97 inches on each side, 39 grams — with a clip-on design so it rides on a collar or pocket, and a color screen showing real-time status. No drivers needed.
The feature list is where it earns its keep. Seven voice-changing modes (robot, male-to-female, female-to-male, youth, queen, lolita, childlike), each with 10 levels of fine-tuning. Three sound modes — karaoke/KTV, recording studio, and electric — that shape reverb and dynamics for live streaming, dubbing or online karaoke. Connectivity is broad: Android over Type-C, Apple over Lightning, computers, PS4/PS5, Xbox One, with plug-and-play through 3.5mm jacks or OTG. Type-C and Lightning adapters are included so you don't have to hunt for dongles.
Then there's the kit angle. It ships with a charging cable, an audio cable, headphones, and both adapters — an all-in-one box you can open and use immediately for gaming, streaming or calls. Audio input supports auxiliary and microphone; output is TRS; connectivity runs auxiliary and USB.
Who should buy it: gamers doing role-play, streamers who want voice effects without a PC plugin chain, karaoke hosts, short-video creators dubbing audio, and anyone who wants one small box to juggle phone, console and PC audio. Who should skip it: anyone who needs neutral, accurate monitoring. This is a creative tool, not a reference chain — and if you're chasing the kind of thing people describe as transparency mode headphones for exercise, that's a headphone feature this kit doesn't address at all.
• Best for splitting a cue signal to two headsets → Rockville RC1DTRS. One 1/4" TRS in, two 1/4" TRS out, shielded and passive.
• Best for voice effects and streaming → DIANMO A9. Seven voice modes with 10-level tuning and three sound modes.
• Best for studio-grade signal integrity → Rockville RC1DTRS. 100% copper conductors and 90% OFC spiral shielding built specifically for EMI/RFI rejection.
• Best for console and phone compatibility → DIANMO A9. Type-C, Lightning, PC, PS4/PS5 and Xbox One, with adapters included.
• Best for a complete out-of-the-box kit → DIANMO A9. Headphones, cables and adapters all in the box.
• Best for zero setup and zero power → Rockville RC1DTRS. No battery, no drivers, no charging.
• Best for portability → DIANMO A9. 39 g and under two inches square, with a clip-on mount.
• Best for DJ booth monitoring setups → Rockville RC1DTRS. Dual headphone monitoring and DJ cueing are exactly what a 1/4" TRS splitter is for.
If a friend asked me which to buy, I'd want to know what they actually own. If they run a mixer or interface with 1/4" outputs and want two people monitoring at once, I'd tell them to get the Rockville RC1DTRS — it's cheap insurance against a booth problem, and the shielding spec is the right one for the job. If they stream, game or make videos and want voice effects plus a headset in one box, I'd point them to the DIANMO A9. For me personally, buying for a DJ setup, the Rockville wins — but that's because my need is signal routing, not entertainment. And to close the loop on the exercise angle: neither of these is a workout product. If you specifically want transparency mode headphones for exercise, deep bass on ear headphones for exercise, or touch control in ear headphones for exercise, you're shopping in a different category entirely. Check the current price on Amazon before you commit.
Yes — and that's exactly the pairing the Rockville RC1DTRS is built around. It splits one 1/4" TRS signal into two 1/4" TRS outputs, which is what you need for dual headphone monitoring and DJ cueing from a mixer or interface.
You need something to cue the next track privately, and in practice that means headphones. On a 1/4" TRS setup, the RC1DTRS lets two people share that cue feed without unplugging anything.
To hear the incoming track before the audience does, and to beatmatch against what's playing. The RC1DTRS supports that workflow by duplicating the cue output to two pairs of headphones with shielded, low-interference signal.
No. The A9 is a voice changer and sound card kit with 7 voice modes, 3 sound modes and a clip-on 39 g body — it's for streaming, gaming and karaoke. For monitoring and cueing, the Rockville RC1DTRS is the right tool.
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