speaker protection relay suitability

I have a 2 different speaker protection boards from ebay and would like some advice about the suitability of the relays used.


Relay used:

http://en.hfapi.cn:8080/Uploads/PDF/HF105F-1_en.pdf

http://images.100y.com.tw/pdf_file/29-SLA-12VDC-SL-C.pdf

1. Is the rating of these relays sufficient for speaker protection purposes?

My amp will be modulus 86 i.e. a lm3886 gainclone. At this stage my supply rails will be ±35 V but am considering a unwinding my transformer to lower this closer to ±30 V. Both relays are rated at 28VDC.

2. Will using these relays put any distortion in the signal path? The whole point of the modulus 86 is low distortion. Is this an issue?

3. Do I even need speaker protection for particular this amp? lm3886 nested in an opamp. Is it likely to fail? My speakers are really expensive for me.


Maybe the solution is to get a different relay with the same footprint as the ones listed.

Thanks for your input.
 
I don't like relays like that. I did some measurement with the contact resistance, which is - I feel- th most important. Omron G8P had the contact resistance about 10mohm, the G2RL2 with 2 contact parallel had 2,5mohm. So I use G2RL2.
Another idea, that I shorting the loudspeaker terminal, in case of the relay release, because it save the speaker if one of the relay contact welded together by the DC voltage.

Sajti