Seamless Loop SFX: ElevenLabs Sound Effects v2 vs Mirelo SFX 2.0

Pick ElevenLabs Sound Effects v2 when the sound has to loop: it has a loop switch and takes fractional durations. Pick Mirelo SFX 2.0 when you want one uncompressed WAV of up to 30 seconds delivered in a single request.

Both models are live on HiAPI. Open ElevenLabs Sound Effects v2 to write a description, set a length and switch loop on; open Mirelo SFX 2.0 for one whole WAV from a description. New accounts get 200 credits on sign-up.

The rows that matter for looping

Game ambience, stream backdrops and app room tone all play on repeat, so the decision comes down to these eight rows:

loop shapes the join between the first and last moment of the clip; it does not stretch the audio. Request 10 seconds with duration_seconds: 10 and switch loop on; both settings take effect. Mirelo SFX 2.0 has no such switch. It puts the control in a whole-second length from 1 to 30 and a 2,000-character description, which suits a stretch you play once rather than repeat.

For a longer bed, ElevenLabs tops out at 22 seconds per clip ($0.0638), so anything longer is two or three clips butted together. Mirelo SFX 2.0 reaches 30 seconds in one request, with no seam to splice yourself.

The full format and per-second comparison lives in Mirelo SFX 2.0 vs ElevenLabs Sound Effects v2. This piece stays on looping and long ambience.

One machine-room description, one run each

The same description on both, 10 seconds requested: duration_seconds: 10 with loop on for ElevenLabs, duration: 10 for Mirelo.

Steady industrial machine room hum: low rotating fan drone, faint electrical buzz and a distant metallic resonance, even level from start to end, seamless loop, no music, no voices.

One description, generated once on each; the ElevenLabs take used loop=true and prompt_influence 0.4.

Use this prompt → The link fills the description only, so set duration_seconds to 10 when it opens, then switch loop on yourself. On the Mirelo side, run the same description with duration at 10.

Both arrive at 10.000 seconds, and the difference sits in the spec sheet: one stereo MP3 that drops straight into a timeline, one 48 kHz mono WAV. To check the join, put the player on repeat and listen at the seam.

A second pair: a 1-second UI cue, one run each

Short cues are what these models get batched for most: button feedback, pickups, notification arrivals. One one-second description, generated once on each:

Crisp UI confirmation tone: two quick glassy notes rising, clean digital sound, short and dry, no reverb tail, no music, for an app success state.

One description, generated once on each; the ElevenLabs take used prompt_influence 0.5 with loop off.

Use this prompt → The link fills the description only, so set duration_seconds to 1 when it opens and leave loop off.

At the one-second mark the gap is price: $0.0029 against $0.0215. Batching a whole interface set multiplies that difference into how many versions you can audition.

Which one for which job

• Level ambience in a game → ElevenLabs Sound Effects v2, where loop hands the join to the model, so there is no crossfade to build downstream.
• A stream backdrop that runs all session → ElevenLabs Sound Effects v2, whose fractional lengths let you match a 12.5-second window exactly.
• App room tone that sits there all day → ElevenLabs Sound Effects v2, at $0.0029 a second, so a long bed stays small.
• Short UI feedback → ElevenLabs Sound Effects v2, $0.0029 for one second, with the 22-second ceiling far out of reach.
• Film foley, played once → Mirelo SFX 2.0, whose 48 kHz mono WAV goes straight into the session, in whole seconds that match a cut.
• One 20–30 second ambience bed → Mirelo SFX 2.0, generated whole in a single request.

What does switching cost?

Very little. Both models run on POST https://api.hiapi.ai/v1/tasks with the same API key, and both return through GET https://api.hiapi.ai/v1/tasks/{taskId}. Two things change:

• model: elevenlabs/sound-effects-v2 or mirelo-sfx-2.0.
• input: the length field is named differently. ElevenLabs uses duration_seconds from 0.5 to 22 and accepts fractions; Mirelo SFX 2.0 uses duration from 1 to 30 in whole seconds.

A pipeline already sending duration_seconds to Mirelo needs that number rounded and the loop parameter dropped. Going the other way, send the requested seconds in duration_seconds and switch loop on explicitly.

FAQ

Does turning loop on change the length? No. Loop only shapes the join, and the clip is as long as the value you put in duration_seconds, so 10 gives you 10.000 seconds.

Can Mirelo SFX 2.0 produce a looping clip? It has no loop switch and returns one continuous WAV. To repeat it in an engine, crossfade the ends on the playback side.

How do I cover a 60-second bed? Three 22-second clips end to end on ElevenLabs Sound Effects v2, or two 30-second clips on Mirelo SFX 2.0.

Run one looping bed

Copy the machine-room description above and generate it on ElevenLabs Sound Effects v2 at 10 seconds for $0.029, on repeat, listening at the seam; then run the same 10 seconds on Mirelo SFX 2.0 for $0.215 and play the two back to back before you pick how your player handles the loop.