Multiple Bluetooth speakers simultaneously

Solution 1:

You cannot use the same Bluetooth device profile with more than one deivce at the same time. You won't be able to do what you want to do.

For a listing of all the different profiles, see this Wikipedia entry.

But I can have multiple Bluetooth devices paired to my iPhone. I have a keyobard, a headset and speakers.

Each uses a different profile. Your keyboard is considered an HID (Human Inteface Device) while your headset uses the HSP profile and your audio (speakers) likely uses the A2DP profile.

These profiles are 1-1. Meaning one profile to one device at a time.

If you want stereo get a stereo receiver that supports Bluetooth.