Thiel Owners

Long ago and far away, I once heard a pair of 3.5s that took my breath away. The owner had set them up in a very nice room, constructed of plaster on structural brick with 2: 6' pocket doors and openable windows on one side. So, the room was effectively non-resonant and adjustable.
The speakers flanked the fireplace, creating a varied reflective surface. 12' ceiling height. Magnificent.

That pair had dual inputs; I don't remember whether that was standard or a modification. The amps were Phase Linear 400s, top notch in 1980. Each amp drove one speaker, with one channel driving the bass and the other the mid-highs. Same amps, same cables on all 4 circuits. Equalizer affecting only the woofers.

What a trip.  

Oops, the place was correct, so year must have been 1982 and the model must have been the CS3. Who knows where the memories go?  The 3.5 was a major advancement; the amp arrangement would apply, and the results so much better.

tomthiel
Thank You for sharing a bit of history with us today. Agreed, there is nothing finer than a sweet pair of loudspeakers set- up properly for audition.
Happy Listening!

As Oblgny has already suggested the 3.5’s work best with the 12 dB boost compensating for the natural (and superior) sealed box roll off. Allowing the speakers bass extension that only much bigger and more expensive speakers are capable of. Though perhaps without the ultimate loudness those bigger, more expensive speakers can provide. Yes, the 3.5’s don’t dig below 4 Ohms, and the impedance actually rises at the lower frequency range, which should offset to some degree that rather large 12dB drain on the amplification. Still 12 dB is considerable draw. With their shallow cross-overs, under  powering this range can suck power further up into the critical mid range and even beyond. Enough power is required not only for ultimate loudness but for overall linearity and coherence. 

I wonder if anyone has tried the eq options on the full core Roon platform? This might be a modern inexpensive (free?) option/upgrade to the OEM eq? It would at the very least now offer balanced connection options. Furthermore, the full core Roon platform also offers room correction, which might alllow the bass boost to be customized to one’s room rather than to a theortical anechoic model. Such room correction could even offer consideration of different room placement. As in the customary positionig the room correction could negatively effect the all important direct sound to correct the reflected sound. But....if the speakers were placed directly against the back wall, the correction would be more uniform, and proved natural bass boost requiring less amplification demands.

Of course for the pure analog crowd this might be an anathema. I am still wondering how viable it would be to convert 2 single ended stereo OEM eq’s to mono balanced units particularly for those with digital phobias.

I have used a 31 ch. Equalizer, dbx1231, and been able to make some room corrections, of course within reason. These EQ have a balanced out, is that what you are wondering about using 2 EQ? By the way, in my experience, the mid range or higher did not suffer from using an under powered amp, at moderate loudness. 88 dB at 2 watts is plenty for a small room listening to instrumental music.