Not unless you want to go vintage from the age of tape.
You need to understand the whole purpose of a tape loop. It was to select an input record it and listen off the playback head of three head machines. Most domestic recorders had heads that were record and playback, so you could not off tape monitor anyway. Few used the tape loop for what it was designed for. It was to spot problems in recording such as fowled head or tape saturation so a whole recording was not ruined.
This is a picture of the tape path of one of my tape machines. All my recorders have at least thee heads. This is the tape path of my Revox A700.
The head on the far left the erase head which wipes the tape clean. The middle head is the record head and receives the signal form the tape out with Eq and record bias added. The head adjacent on the right is the playback head. This sends the signal from the tape after EQ back into the preamp section via the tape in, so the tape can be listened to as it is being recorded.
This ingenious tape loop system came to be used for the insertion of all kinds of equalizers and processors. However once tape machines, especially the three head variety became the preserve of vintage buffs and archivists, the tape loop disappeared with the tape machines.
You can only use equalizers now if you have one of two conditions.
1. Separate pre amp and power amp. Even then the sub will not be equalized unless you connect the preamp to the power amp via a mixer and connect the sub out from the pre amp to the mixer as well.
2. If you have a tape switch bus connected to the system you can equalize analog signals only between the switch bus and the preamp, integrated amp or receiver.