Aadams

Nice work. I think you have effectively implemented 2pi placement as depicted in the Allison paper. For the LST the minimum dimension from woofer center to baffle edge is the same or a bit greater than the depth of the cabinet which, as Allison showed, makes it act like it is in the wall when it is against the wall. The AR9 implements the placement shown below to achieve flat bass and extends a bit deeper because of the crossover and dual woofers. Are you using the Crown?

The LSTs are perfect for your listening habits. Excellent choice. The LST gives up little to the 9. Very few recordings play lower than the 3db down point of an LST with optimum placement. From C5 to C8 you are hearing the mids predominantly over tweeters, which are almost exclusively dedicated to high harmonics. When you rebuild the tweeters you will add a feeling of more space and clarity.

Your welcome, but on this topic I am just passing along the help I received over the years from @Pete B,@tysontom, @Steve F and some other member names I can't recall now. PS I am not sure you have enough listening space to hear the real difference between the AR9 and LST, at least not from a single listening position.

Yes, the height is good. I did not know you had so little wall but you are at a good starting point. As long as the cabinet is flat against the wall the woofer will see it as as a baffle extension. Note, you are already so close to the corner you may get a noticeable bass peak. If the right (or left) side of the cabinet is within a woofer diameter of your window wall it will behave as if placed in the corner. If you don't like the bass, you could probably bring the speaker toward you to the wall break and still have enough wall for the baffle, and maybe get smoother response. Your ears will tell you. The gabled ceiling gives the room some good irregular dimensions to minimize room modes. Looking forward to your report. Adams JIC your interested -- this link to the library copy of the Roy Allison engineering paper, "The Influence of Room Boundaries on Loudspeaker Power Output" http://www.classicspeakerpages.net/library/allison/other/technical_articles_by_roy_f/

The arrows are pointing to the opposing walls on the left and right. The LSTs would be flat against the walls. LSTs and Allison speakers were all about reflected sound being dominant over direct sound. When listening to the LST, there is no practical listening position that permits direct sound to predominate. If you read the Allison brochures some of the recommended placements for floor standing Allison 3 ways were opposing walls. The "Allison effect" is about ways to use room gain and speaker placement to optimize bass in full range box speakers. Your LSTs incorporate Allison's work in their cabinet design, which makes the wall become an extension of the speaker baffle if you place them correctly.

Given your limitations for space I think Roy Allison would recommend that you try the placement in this photo. You can do this because they are LSTs. The KLHs are just the right height for LST stands. Rebuilt tweeters from either of the recommended sources are a huge improvement, no matter how well you think they sound now. It appears, there is nothing wrong with the cabinets that Howard's restore a finish won't adequately fix.

They are in a really good, restorable state. Don't forget to replace the FNM 2 fuses with new ones. Old fuses can cause quirky behavior in LSTs and make you question your restoration work. Seeing the back panel, I am going on record saying they have Spragues inside. Every piece of info you will need is spread over the twenty years of posts in this forum and the library.

I am glad they are in the hands of an AR enthusiast. There were only around 1500 pair made. You will do them justice.

Nice work. Have the remaining three been rebuilt in the same way? Do you intend to offer tweeter rebuilds to Classic AR users in the EU?

Gionvanni, Roy Allison agrees with you.

I have been thinking about your progress on this project. Good Job.... And a good objective/subjective review. Adams

The woofer frame appears correct. The refoam job is not correct. The foam surround is not correct. It should be whole with no seam. The surround placement on the spacer ring appears too eccentric. It is not normal in the photo. The glue job is a bit sloppy. If the price is especially attractive they might be worth purchasing for restoration.

If your AR5 tweeter is an untouched original it is not a good reference standard. Rebuilt original tweeters sound nothing like worn out originals. Rebuilt originals restore all the output you are missing, which is substantial, without encroaching on the midrange. I am not saying you should purchase rebuilt tweeters, just that your tired AR5 tweeters are not the correct measuring standard. I listen to 3as with rebuilt original tweeters and 9s almost everyday on the same source. They sound practically identical above 5k, which is significant considering the 9 mid crossover point is 7000hz. The sound of the original tweeter in the AR11 restored by your friend might serve as a better reference point.

I can't understand a word of it, but this recording of 17th century Italian Pop Vocals (Madrigals) is a showpiece for the sound quality of Hi Res Lossless. Totally acoustic, vocals with string and harpsichord accompaniment. Performed against a palpably silent background, the musicianship displayed in the execution of these intricate melodies and harmonies is amazing. It probably helps that all of the singers are Italian. If you stream Irish or Celtic acoustic, you might like this. I know I said the previous post was my final one in the thread.

No intent to discredit. Your mechanical work is quite skillful, but not everyone who visits this site knows or recalls that you are repairing tweeters and modifying speakers to meet personal goals. "Operates to my satisfaction" is not the same as "Operates within factory specs" without verifiable evidence of some kind. I recall your work on the Super tweeter, not the 3/4 inch, but from your writings in this thread and mentions in other threads regarding AR speakers, I mistakenly assumed you must have squeezed in some 3/4 inch experience somewhere that I had missed. Many of the latter posts in this thread reference moribund and dead 3/4 inch tweeters. No posts regarding orange domes after the first page. This thread should have been split into 2 other non-AR threads long ago.