Comparison

7XDXFM 4OP FM Loop Maker vs PO

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

7XDXFM 4OP FM Loop Maker

Create complex FM synthesizer sounds and sequences with this 7-track music production tool. Features include LFO modulation, piano roll editing, and built-in effects like echo and reverb. Sync with other apps via Ableton Link or MIDI, and export your creations.

Highlights
  • 4 operator FM synthesizer
  • 7-track sequencer
  • LFO modulation
  • Piano roll editing
  • Echo and reverb effects
  • Ableton Link and MIDI sync
  • Audio export
Features
Read full description

Welcome to 7XFM - a 4 operator FM synthesizer and 7 track sequencer with Ableton link, recording, and routing for your audio to connect to AUM or Audiobus. With most of the important synthesizer settings found in most FM synthesizers and added modulation. Modulate the operators over time with the LFO, plus dynamics for amplitude and pitch of modulators wherever you add an ACCENT Pick from a range of preset frequencies for carrier and modulators (influenced by Orla DSE/Bohm FM Expander synthesisers) Create those classic FM sounds from punchy Lately Bass to smooth 80s fm pads or crazy chaotic FM sound effects. Keep in Sync with your apps using Ableton Link or MIDI Send MIDI clock or MIDI note as separate channels. This app was influenced by the Korg Volca/Electribe FM synth sequencers as well as TX81z and Orla DSE9 FM synthesizer SEQUENCER The sequencer has 7 channels containing a sequence dedicated to a tone sound. You can create sequences using step edit or bring up the PIANO ROLL for quick step placement. You can just randomly generate steps - either random choice pitches or SELECT NOTES. or shuffle the sequence PIANO ROLL! its easy to create melodies and bass lines fast! Double click step to cycle though octaves or erase across step with finger motion. Mask keys so you can define keys and swipe across bar with finger motion to lay down steps easily. EFFECTS! Each track has echo, reverb and a low pass filter similar to add some spacial atmosphere or emulate an analogue synthesizer. COOL CREATIVE FEATURES! 2nd and 3rd voice generators with detune and transpose by semitomes for fat chorus effects or chorded notes Auto level ducking switchable input from bass metronome or any track Playback timing of notes on sequences - steps triggered either at 4th or 8th timings - a sequence can play slower and last longer equivalent to 512 steps Added a “mutate tone” option that slowly modifies the sound randomly away from original. Added “randomise tone” that completely creates a random tone from fresh. GLOBAL TRANSPOSE! All channels can be transposed simultaneously on the fly to create great layered melodies, and you can choose which ones are ignored (TR LOCK) for things like sound effects. SONG MODE is like a playlist of programs, where you can chain programs from either the current loaded program or imported saved program file. A scene can have any track muted, global transposed, reset counter at start (D.C.) "Da Capo", override step length and control the BEAT ON metronome mode. You can then arm sampling and record the chained programs and export the audio. Save your Songs and they won't be affected by changes in the original programs. EXPORT! You can easily record a perfect loop of whatever is playing and export via AudioCopy or Audioshare as well as email and IOS Folder Export your tones, sequences or whole programs to another device, friend or saved elsewhere SYNC This is compatible with Ableton Link as well as MIDI so you have options for connecting to external hardware or other apps while keeping in time AUDIO ROUTING Output the main audio to other apps such as Audiobus or AUM to allow those apps to record or process your creations EXTERNAL CONTROL Control Mute of tracks with midi keys, volume of track-channel with MIDI CC 176 for channel 1, , 177 - channel 2 etc .. MIDI note input of one track's sound available while sequencer is playing all tracks - selectable tracks controlled by all midi channels (omni) THIS DOESNT ACCEPT MULTIPLE MIDI PER SEQUENCE.

About

PO

Design and edit drum sounds, kits, and patterns for Teenage Engineering's PO-32 Tonic. Transfer your creations to the device via audio. Back up and edit existing sounds, and import/export patches from Microtonic.

Highlights
  • Shape 16 sounds with 21 synth parameters
  • Program 16-step patterns with accents
  • Send kits, sounds, or patterns via audio
  • Back up and decode PO-32 data dumps
  • Import/export Microtonic patches
  • Local library with tags and favorites
Features
Read full description

PO-PatchStudio designs drum sounds, kits and patterns for Teenage Engineering's PO-32 Tonic, then sends them to your Pocket Operator over sound. Free, with no ads and no account. The PO-32 has no USB data connection. It loads new sounds the way an old modem does, by listening through its microphone. So this app does the fiddly part on a proper screen: build a kit, hold your phone next to the PO-32 and press play. WHAT YOU CAN DO - Shape all 16 sounds with the full set of 21 synth parameters, plus both ends of the morph - Program 16-step patterns on the pads, with accents, and hear them before you send - Send a whole kit, a single sound or a pattern to the PO-32 over audio - Back up your PO-32: record its data dump through the microphone and the app decodes it into a kit you can edit - Import Microtonic .mtdrum and .mtpreset patches, including files from older versions of Microtonic, and export your sounds back out - Keep kits, sounds and patterns in a local library with tags and favourites WORKS WITH - PO-32 Tonic - Also sends drum sounds to the PO-35 Speak's built-in Tonic channel HOW TRANSFER WORKS Put the PO-32 in receive mode (press acc + sound), turn your phone's volume up and play the transfer into the PO-32's mic. To back up, start recording in the app, then hold write and press sound on the PO-32. Previews come from an open-source recreation of the PO-32's synth, so they sound close to the hardware but not identical. Once a sound is on the PO-32, it plays through the device's own engine. A NOTE FROM ME I'm a solo developer and a PO-32 owner. PO-PatchStudio stands on the open-source libpo32 library by Eric Lewis and years of reverse-engineering by the Pocket Operator community, which is why it's free. If something is missing or broken, tell me. Not affiliated with or endorsed by Teenage Engineering AB or NuEdge Development AB. Pocket Operator, PO-32 and Tonic are trademarks of Teenage Engineering AB. Microtonic is a trademark of NuEdge Development AB.

Screenshots

7XDXFM 4OP FM Loop Maker4 screens
PO4 screens

Verdict

The call

The clearest difference is review sentiment: PO at 100% against 7XDXFM 4OP FM Loop Maker's 50%. PO also leads on price (Free vs $1.99) and rating (5.0 vs 4.0). 7XDXFM 4OP FM Loop Maker's advantage is in-app purchases (none vs 3) and ratings volume (6 vs 1). On ads, device support and iOS requirement there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

PO is free to download; 7XDXFM 4OP FM Loop Maker costs $1.99 up front. PO sells 3 one-off in-app purchases. 7XDXFM 4OP FM Loop Maker asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

PO holds the better App Store score, 5.0 against 4.0. That said, the two scores are not equally well evidenced: 7XDXFM 4OP FM Loop Maker has 6 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 50% of 7XDXFM 4OP FM Loop Maker's written reviews are positive against 100% of PO's.

UpkeepUpdate frequency

7XDXFM 4OP FM Loop Maker ships an update every 5 days, PO every 2 days. The most recent releases landed on October 24, 2026 and October 25, 2026 respectively.

Scorecard7 real differences · 3 level
7XDXFM 4OP FM Loop Maker versus PO: the parameters behind the verdict, then further details
Parameter7XDXFM 4OP FM Loop MakerPO
Price$1.99Free — better
Rating4.0 (6 ratings)5.0 (1 ratings) — better
Positive reviews50.0% of reviews100.0% of reviews — better
Number of ratings6 — better1
Update frequencyEvery 5 daysEvery 2 days — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaidFree — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.615.0 — better
Further details — not scored
Size14 MB14 MB
Age rating4+4+
DeveloperRob WilmotPhoton Consulting Limited

Customer experience

7XDXFM 4OP FM Loop Maker

All ratings6 ratings
Positive66.7%
Neutral33.3%
Negative0.0%
Written reviews4 reviews
Positive50.0%
Neutral50.0%
Negative0.0%

PO

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

7XDXFM 4OP FM Loop Maker

No in-app purchases

3 purchases

PO

One-time3
  • Tip: Thanks$5.00
  • Tip: Big Thanks$10.00
  • Tip: Huge Thanks$20.00

Questions

Is 7XDXFM 4OP FM Loop Maker free?
7XDXFM 4OP FM Loop Maker costs $1.99, with no in-app purchases.
Is PO free?
PO is free to download, with in-app purchases available.
Which has better reviews, 7XDXFM 4OP FM Loop Maker or PO?
PO is rated higher. 7XDXFM 4OP FM Loop Maker averages 4.0 out of 5 from 6 ratings, while PO averages 5.0 from 1 ratings.
Do 7XDXFM 4OP FM Loop Maker or PO have ads?
Neither 7XDXFM 4OP FM Loop Maker nor PO shows ads.
Which is updated more often, 7XDXFM 4OP FM Loop Maker or PO?
7XDXFM 4OP FM Loop Maker ships an update every 5 days, and PO every 2 days. Most recently, 7XDXFM 4OP FM Loop Maker was updated on October 24, 2026 and PO on October 25, 2026.

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