Linea Research unwanted latency compensation

[EA Support]

EA Support

1 September 2026 at 9:01 am #501359

The way the latency compensation should work – and the way it works in FIR Designer M – (by way of an example) is as follows:

Channel 1: FIR length 2048, FIR delay 256
Channel 2: FIR length 768, FIR delay 50
Channel 3: FIR length 384, FIR delay 32

The largest FIR filter delay is 256, so the other channels are delayed so that their ‘delay’ location is moved to 256.

Channel 1: FIR length 2048, FIR delay 256, no latency compensation
Channel 2: FIR length 768, FIR delay 50, latency compensation 256-50=296
Channel 3: FIR length 384, FIR delay 32, latency compensation 256-32=224

So, the goal is to match the FIR delay locations, and obviously the largest channel FIR delay is the reference.

Note that the FIR filter lengths do no affect the latency compensation.

Also (in FIR Designer M), if the channels each have delay, any common bulk delay is removed. For example, if the channels have

Channel 1: Delay 1ms
Channel 2: Delay 0.3ms
Channel 3: Delay 1.1ms

then 0.3ms is removed from all channels. Bulk delay (for the preset) can always be added back, by the user, to each channel or to the input channel.

In your message (below), you mention that Linea Research delay compensation is using the FIR filter lengths. This doesn’t seem right to me and it’s definitely something for Linea Research to look into.

The SFI file format is text XLM, so you should be able to edit a SFI file with a text editor. The FIR Designer “Filter delay” parameter is written to the file as the “latency” field.

Regards,
EA Support

I have a question, I searched the support forum but apparently no one has encountered the same problem. Also had contact with Linea Research about this problem through the dutch distributor and also Martin Audio (they sell OEM Linea Research). Linea and Martin acknowledged the problem but don’t want to change firmware or anything because of delay-changes in already operational systems worldwide, completely understandable.

Short as possible this is the problem we have:

When loading a fir (.sfi) file generated with FIR Designer, Linea Research amps naturally compensate delay at the outputs that are routed from the same input path (example: input path A routed to output 1 and 2). When output 1 has a fir.sfi loaded, output 2 (no fir.sfi loaded) gets a delay compensation equal to the “Filter length (samples)” in the export tab of FIR Designer. This delay compensation is around 2x longer (depending on the fir-filter design) than the “Filter Delay (samples)”, which is the extra delay added to output 1 when loading the .sfi, and easily verified by SMAART measuring.

Since I found out about this my work-around has always been: every output gets its own input path. This holds for the 4 channel products.
But for the 8 channel (and recently 6 channel) products this is not possible since there are always only 4 input paths. I am in the process of building settings for several Martin Audio 3 way cabinets and these are all done with 8ch amps/4input paths. For a 3 way top cabinet (low mid high), we run into problems because its not possible to FIR “mid and high” and not FIR “low” (3 outputs coming from input A).

I get long unnecessary delay compensation on the low-out, and I have to manually extra compensate for this on the mid high out.
I also tried to load a null fir file in the low out, this doesn’t fix the problem. This is the way Linea Research processing deals with this.
Is there a way to eliminate the compensation in the export, and tell Linea Research not to do this, because in a lot of situations (read all) we never want this compensation. We can delay manually where needed.

Maybe I can edit the .sfi with a text editor or maybe there is a different method of export where Linea Research doesn’t compensate.
I hope you can help me with a solution, would make us so happy 🙂

Thanks, and thanks for the really powerful smart software! Cannot do without it anymore :-).

Cheers!