Based on the information gathered, here’s a summary of some of the best RAAL tweeter bookshelf speakers known for soundstage, imaging, and warmth that you might consider buying used for around $750, sequenced from best to least best:

1. RAAL-requisite Model 140-15D - This is a high-performance ribbon tweeter speaker that offers exceptional soundstage and imaging, with a focus on highs and mids. It’s well-regarded for its immersive quality and can sometimes be found used within your budget.

2. Dynaudio Excite X14 - Known for its warm sound and excellent imaging, this speaker delivers a balanced sound profile that includes lush mids and controlled bass. The Dynaudio brand has a reputation for quality, making these a solid choice.

3. Swans M200 Mk III - These speakers are well-respected for their audio reproduction capabilities, utilizing a ribbon tweeter that provides clarity in the highs and a respectable bass response. They are often praised for their immersive listening experience.

4. ELAC Uni-Fi 2.0 UB52 - Designed by audio engineer Andrew Jones, these speakers are capable of delivering rich sound with a good balance between highs, mids, and bass. They are a bit more conventional compared to the others on this list, but still offer a compelling experience.

5. Q Acoustics 3020i - Although not RAAL tweeters, these speakers boast excellent imaging and warmth, with a slightly warmer sound signature than others. They provide decent bass and an engaging soundstage, making them a good option for those looking for value.

You might find these speakers on platforms like eBay, Craigslist, or Audiogon, where used audio equipment is frequently listed. Always check the condition and seller reviews to ensure you're making a wise purchase.

Sources

Good bookshelf speakers with immersive sound for home theater ...Recommended Components 2023 Edition LoudspeakersOur Top Six $700/Pair Bookshelf Speaker Picks for 2021 - AudioholicsELAC Uni-Fi 2.0 UB52 Bookshelf Speakers (Pair), Black (UB52-BK)The Best Bookshelf Speakers for Stereo and Surround SoundOur Top 3 Audiophile Bookshelf Speakers Under $5k ... - YouTubeBest bookshelf speakers 2025 - MixButton Studios

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