Spectron contains advanced controls to help you get
the optimal performance for your setup. Since Spectron contains
several modules within its 64-bit internal DSP chain, there are several
places where you can control its internal buffer sizes. In general, the default
values should give good performance on most systems, but there are some aspects
of host applications that are not detectable by plug-ins. Read this section
for instructions on how to optimize Spectron for your particular setup.
RTAS only: If you are using the RTAS version of Spectron inside Pro Tools, then the first option you should set is Spectron's "RTAS buffer size" found in the General options tab. You should set this to the same value you've set the "H/W Buffer Size" in Pro Tools, under Setups / Playback Engine. If you are experiencing high CPU usage, you should increase both the Pro Tools "H/W Buffer Size" and Spectron's "RTAS buffer size" for a significant improvement. Note that larger "RTAS buffer sizes" will introduce more latency into Spectron's output. You can also set Spectron's "RTAS buffer size" to 32 to introduce no additional latency, at the cost of higher CPU usage.
All plug-in formats: The Spectron Engine requires a fixed buffer size, equal to the number of bands set in the Spectron Engine Options tab. In most cases you won't need to worry about this requirement of the Spectron Engine, but if you are using Spectron at low latencies you may notice high CPU usage or stuttering/dropouts. If this happens, you can increase your host application's latency or buffer size to improve Spectron's performance. If this is not possible or simply not preferable, you can also decrease the number of bands Spectron uses to get better performance.
To find out how many bands should work well with your setup, first you should have an idea of what kinds of buffers your host application is sending. You can use Spectron's Buffer Size Viewer to do this. Once you know what size buffers your host application is sending, try the following:
1) Set Spectron's number of bands to the number that's closest to your host application buffer size.
2) Open a CPU meter. Many host applications have a CPU meter built-in, but if you're running Windows XP you can also press Ctrl+Shift+ESC and select the Performance tab. Note that CPU meters are usually somewhat inaccurate, but we're just looking for relative changes in CPU usage.
3) Start playing audio through spectron. As the audio plays, try adjusting the number of bands and see what effect it has on CPU consumption. Buffer sizes near the host application buffer size are a good starting point, but the best choice depends on many aspects of your system and host application which are beyond Spectron's control.
Using these tips you should be able to find settings that make Spectron work well with your setup. For more tips about Spectron usage, check the Support section of the iZotope web site:
http://www.izotope.com/products/audio/support/spectron.html
As we learn more about how Spectron interacts with various host applications, we'll update these pages with the latest info.