My system is as follows:
* Townshend Rock III turntable with Grado MM cardtridge.
* EAR 834P phono stage
* Naim CDP8i CD player
* First Sound passive "preamp"
* Music Reference RM9 tube amplifier
* Mixed cables - DIY solid silver, Cardas speaker cables

The speakers replace my Thiel CS3.6 floor-standers, in roughly the same locations (corners). The room is sub-optimal in that the speakers are in corners that also house bookcases, and there's a baby grand piano between the speakers along the same wall. However, there's no sign yet of any piano-contributed vibration.

I've been listening to lots of stuff: Beatles, Tom Paxton, King's Singers, Lieder (Brahms, Schubert), Wagner, Gilbert & Sullivan, Dave Brubeck, and a mix of CDs and records.

The first impression is of a very delicate and accurate mid-range. The King's Singers have never sounded better. The mid-horns seem solid and unfussy. The treble is clear, but I think a bit recessed, and definitely less audible than with the Thiels. The bass I'm not quite sure about yet. Clearly the power of the woofer is exciting a couple of room modes, and I will need to build some tube traps or something, and possibly alter the room layout a bit (I'm sitting against the back wall, which is probably not ideal). The most obvious effect is on plucked bass lines, and also some coloration on male voices. But except for the notes that are too loud, the bass seems clear and unobtrusive. I don't know if I'm really getting all the extension I was expecting - this may be because of the bookcases, or (and I hope not) it's possible the cabinets leak. I have been unable to detect much port action so far.

The other major change is the increased level of dynamics. I find I have to adjust the volume for every recording separately - I never needed to do that before. Popular recordings with lots of compression need to be turned well down. Classical recordings with wide dynamic range can be turned up and I still get good pianissimo, with exciting climaxes. The bass excitation limits my ability to listen loud - especially with bass or baritone voices.

I should mention my long-suffering wife's responses - she has three (presented in unvarnished form):

1. "They are bigger than you led me to believe"
2. "They are uglier than I thought"
3. "They sound much better than the old speakers."

...so I guess I get to keep them, but I will need to finish the veneering and clean up the wiring etc.

So once again, Wayne - thanks for all your support through the process, and thanks for the design. The project was worthwhile, and has given my music collection a new lease of life. I look forward to more projects - office and garage speakers, and perhaps some room acoustics modifications.

Regards,
tim

• Pictures

Check room wall and bookshelf panels for sympathetic vibrations. This is one of the most troublesome issues I find. Shelves sometimes buzz, and cabinets with closing doors sometimes vibrate door against stop. Do something to preload the panels that make your shelves back walls and see if you can find ones that are making noise. Chances are, you'll find a lot of things in your home that buzz when vibrated. The different woofers and setup may energize them differently and make it more noticeable.

Last night I "installed" four bags of R19 insulation under the piano and in corners. The bass boom is gone, but the treble is now definitely too light, so I've overdone it a bit. I'll keep on experimenting and I plan to take some measurements over the weekend.

The most obvious problem I can detect at present is that the front of the bass cab vibrates a bit, despite two glued-on braces and two cross-braces (above and below the woofer).

Would it be a good idea to put in some kind of compressible bracing between the back of the woofer and the front of the cab? Or should I just add more glued-on pieces to the inside of the front?

If you find room modes are troublesome, you may want to add a couple subwoofers. This may seem counterintuitive, especially if you feel that the bass is strong. But what will happen is bass will be made more smooth as a result. Use CARA and figure out where to place the subs. I have found many cases where the four opposing corners are best, and others where they're not. Of course, your decor will determine what you have to work with too.

I usually suggest the additional woofers be the same as the ones in your sevens. They don't have to be cornerhorns, but they surely can be. If not cornerhorns (with mids and tweeters), then low-pass them very low, below 100Hz. This prevents localization and improves integration, by keeping sound sources acoustically close. Or you can go with a different approach, using woofers like the LAB12 that are tuned for a very deep range. This lets you hit even deeper bass notes while providing smoothing of the overlapping range. You may be able to install subs in cabinets that fit under existing furniture. You can usually find a configuration that models well in CARA and that also fits in nicely with your room decor.

I've got 3 stacks (John Risch cheap 'n dirty bass traps) of R-13 fiberglass that comes in rolls in corners.
That tamed the bass boom in my room: poorly suspended wood floor.

I cut plywood circles for the tops of the stacks and stapled colored burlap to the edges which skirt the rolls down to the floor. Kat likes to sit on the one by the window. After she bakes you a pie you might let the little woman choose the fabric herself.

The thicker the insulation the lower the frequencies absorbed so
your R-13 shouldn't be lightening the treble. Just the opposite. There should be more clarity. I think you're hearing the lesser extension of a horn tweeter compared to your Thiels. Might want to consider a JBL 2405 or other super-tweeter.

Just my buck and a quarter.

Skip

Rooms without raised hardwood floors are usually better. However, if the walls are rigid, then modes aren't well damped. Rooms with rock, concrete or brick walls usually have more modal problems than those with framed drywall construction. Rooms like these can benefit from bass trap panels. Sometimes, things in the room act as resonators, and that causes problems too. Built-in cabinets sometimes resonate or buzz. Large free-standing furniture sometimes resonates. So there are lots of things to look out for.

But in any case, I'll see what it sounds like under the floor. I imagine that if I use Cara to work out room modes, and then when I measure I find something different, it may be because of the sub-floor space?

I have some other things to do as well - explore moving the piano to another part of the room to let the horns do their thing with fewer obstructions; put some kind of absorbent pad under the piano (a Jon Risch-style trap lying on the floor?); and then we'll see where I am.

The room needs to get back to the clean and minimalist look it had before I put all the stuff in there - it is meant to be a peaceful place, not just a listening room...

Any suggestions in the sub-$100 range?