tim

* Audible response below 20Hz if I turn up the wick a bit.
* Real response seems to start at about 25Hz - small peak at 26Hz.
* Up another 10dB by 35Hz.
* Up to "average" levels by 46Hz - 15dB above the 35Hz figure.
* Small peaks at 67Hz, 100Hz, 160Hz and 290Hz.
* Response drops at 85-95Hz, 110-150Hz, 230-270Hz.
* Narrow suckouts (down 8-10dB) at 110Hz and 270Hz.

This is with three bags of R-19 - two under the piano and another hiding under a coffee table.

I'm a bit surprised there's not more bass in the 25-45Hz range - is this the result of inadequate corners, perhaps?

I can also hear a certain amount of vibration - not sure of every cause, but I could identify a shelf and a table and some CDs as a start. Also the floor vibrates, and I wonder if I should isolate the speakers from the floor?

• Realtraps test cd link

As I said I haven't done this, but I do put four of the dowels
around the woofer cutout to localize the panel reaction to
the woofer acceleration.

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Regards

• Tweeter : Horn Tweeters

I've turned them around against a different wall and finished the veneering (although they still need finishing). This seems to work better as they have more room to breathe. The treble seems improved, which is a surprise, and the overall balance is better too. As you can see from the picture, they are sitting on my hardwood floor, which is less than ideal.

They don't have any feet or isolation of any kind - any ideas as to what I should do there?

The crossover is still loose, and needs a box, and I plan to remove the shelves and build something more effective for CD storage so the speakers are truly in the corner.

I'm constantly amazed at how much more I'm hearing from all my records. It's hard to stop listening - which is the point, I guess

The increased efficiency is the first and most obvious difference. The second is the increased sense of ease and detail in the mid-range. I am hearing a lot of new information. The difference between CDs and LPs is even greater than before - with LPs clearly preferable.

The corner positioning and perhaps the use of horns seems to lead to a couple of changes - more air movement and sense of being involved in the sound which is a good thing. The precise imaging I was used to is not really present any more. I feel there's a bit of a hole in the soundstage towards the center. But there's a benefit too - the sweet spot is much bigger. I can sit in many places in the room and still enjoy a balanced sound.

There seems to be a shortage of low bass with the Pi Sevens, but very good and clear and unfussy mid-bass. The Thiels use a passive bass radiator which gave quite a lot of bass - especially if the speakers are anywhere near a corner.

The Thiel cabinets are much more rigid than the Pi Seven bass cab - double or triple thickness baffle, lots of internal bracing, smaller panels. I never felt any vibration of the Thiel cabinet, but I can detect vibration on the front of the Pi. I plan to take the drivers out and beef up the internal bracing.

The treble is clearly less than with the Thiels, but it's clean and sweet. I might investigate a super-tweeter, but we'll see. The integration between the treble and mid-range seems to be perfectly seamless from anything more than a couple of feet away.

One reason the Pis work well for me is that my amp is a Music Reference RM9 tube amp that is not really at its best into very low impedances. The Thiels go below 2 ohms at certain frequencies, which in addition to their low efficiency makes them tough to drive. A transistorized amp was better at the bass, but worse at the mid-range. With the Pis I can get a good overall performance with my tube amp.

Let me know if you have any more specific questions - I'm still learning about the speakers and I'm sure my views will continue to evolve.

My net conclusion is that they were well worth the trouble to build, and a very satisfactory improvement on the Thiels. I wish they were smaller.

Regards,
tim

• Some first impressions...