The criteria for loudspeaker choices.

@ricevs: Your comments are always welcomed by me (by the way, I still own the Audible Illusions Modulus 2 pre-amp you "modified" for me about 25 years ago. Modified is an understatement; it is a complete redesign, turning the full-function pre into a phono-only gain stage).

I did just as you suggest, using the GR Research/Rythmik Audio Direct Servo-Feedback OB/Dipole Subwoofer (which you at one point were using in your own loudspeaker design, mated to the planar-magnetic m/t drivers that are no longer available. I forget the name of the company that was making them. Danny Richie of GR Research is now offering his own version of that fantastic p-m tweeter.) in place of the stock woofer in the ET LFT-8b.

The combination of the ET LFT-8 planar-magnetic drivers (180Hz and above) mated with the OB Sub is one way to achieve near-state-of-the-art sound at a peasant-income price. IMO. Far superior to the Infinity RS-Ib’s I used to own.

@rpeluso My specific bad experience was with a PSA PerfectWave Transport ($4000 retail). I had three drive failures in 6 years. I played the unit around 4 to 6 hours per week.

I learned that PSA used the cheapest grade of computer drive (around $10) they could buy. These drives are not designed to spin a disc hour after hour. They are made to spin up a data disc, read the data, and then spin down. The choice of this drive for a $4000 transport is unforgivable in my opinion. They knew better and they simply cheaped out. By the time the third drive failed PSA no longer supported the unit and it became a boat anchor.

Second example is the PSA Power Plant 12. The review by ASR showed that the unit actually makes things worse for the downstream component but the biggest problem was that the "High Current" outlet actually reduces the wattage to the amplifier! But even more troubling was Paul's response, accusing Amir of using the wrong outlet. Paul even demanded an apology. Well, his employees (I won't call them engineers) corrected him and he had to admit that ASR did the test correctly. Did he offer Amir an apology? You guess the answer.

Third example is the PSA DirectStream DAC that uses an FPGA processor instead of a typical DAC chipset. This unit is quite expensive and has tested very poorly by Stereophile and ASR. It is actually one of the noisiest DACs available with very poor bit resolution. I won't go into the reasons for this but it is a perfect example of how a company tells a hyped story and charges a lot of money for a poorly engineered product.

For me, the above is enough to decide that I will avoid the PSA brand with prejudice. For the record, I don't trust Audioquest and several other brands that have put out products that have been demonstrated to actually make the signal worse than much cheaper alternatives.

Lastly, I don't want to start a war here. If owners of PSA products love them and hear wonderous sound quality, more power to them. My only advice is to be careful about the engineering design and build quality.

Thanks for the answer!

@8t-note

Have you actually listened to the DirectStream DAC? There are a lot of people who have including myself. I’ve compared it to ASR’s excellent measuring DACs. I was very obvious to me that there is a lot more to sound than numbers. I don’t have experience with other PSAudio products so I can’t comment.

Well, as the speaker designer at PS Audio, I thought I’d chime in.

I’ve never met Bruce Thigpen at any trade shows but, by all accounts he’s a genuis inventor and did a number of useful planar magnetic patents over the years, some of which are licensed by planar magnetic headphone companies among others.

However, the Eminent Tech speakers make me scratch my head. The crossover used is a total mess with broad overlaps and interference between the drivers (almost like there is no filter on the woofer and/or midrange). Cone breakup from the woofer is left unfiltered out and there is a bunch of interference from the resonances.

Also, sensitivty is almost 5 dB lower than specified (about 77-78 dB) and so it’s among the lowest on the market (even lower than magnapan.

stereophile measurements of LFT-VII showing driver responses with crossover

LFT-16 driver measurements

While the smaller LFT-16 looks intially better, the mid and woofer done integrate currently, even when switching driver polarity.

Also, when you have such a high crossover point to the tweeter, the midrange panel is beaming a lot before handing over to the tweeter and the off axis behavior is poor.

As far as crossover parts go, you guys selling crossover part upgrades as a side business have a biased viewpoint as to what is appropriate and perceptually significant. That being said, we use nice components in the FR5, appropriate for it’s price point, I think.