AR-9Lsi Project

[meta_noia_fot]

On 6/24/2024 at 10:20 PM, meta_noia_fot said:

Fingers crossed I’ll be A/B’ing these against my -9’s this weekend. 

I utterly jinxed this project. 

After taking the joint tweeter/supertweeter assembly out of the cabinets to do cabinet work, I decided to test the drivers. One supertweeter read open circuit. I only did an aural test before to test the drivers and must have missed the dead supertweeter since it and the upper midrange tweeter are so close. That’s a pro repair I’ve sent off to Vintage AR. No way was I going to disassemble that giant block if I didn’t need to. 

Also, while testing the second crossover I just finished building, I discovered the 10” woofer I just refoamed has a terrible amount of distortion. It’s buzzing but not in a metallic way. There’s no voice coil rub. I can only assume that the off-kilter spider is causing the noise.

The only other problem I’m aware of on the 10” woofer is my mistake: I installed the lip of the foam surround on the front of the cone, not the back. I realized my mistake while working on the second 10” woofer and felt old glue on the back of the cone. This is the only AR woofer I’ve seen that puts the surround lip on the back of the cone. FYI for Tonegen part no. 1-2100330. Still, I think the more likely culprit for my distortion problem is the spider and not the lip of the surround being on the wrong side of the cone. 

I guess I’m buying acetone tomorrow. So fingers crossed I’ll be listening to these….soon-ish….

[meta_noia_fot]

Well with the working parts I have currently, I got one speaker reassembled. I spent a couple of hours listening to music with the LSi in the left channel and the original -9 in the right, swapping back and forth between the two in mono mode to compare their sounds. 

I was surprised at the sound of the LSi, particularly the HR driver. Very high frequencies are less present on the LSi than the -9. This was particularly noticeable with the sounds of cymbals. I used the tone controls on my -9 and found that they sound very similar if the HR control on the -9 is set to -6db (I run my -9’s usually with all tone controls set to -0db). 

Part of me is worried that the HR driver is underperforming as a result of damage. The previous owner had these hooked up to a low power receiver that I worry may have done some damage to the tweeters. I don’t know if that’s a realistic possibility but it’s been in the back of my mind. Luckily for comparison, I’ll have a HR driver with new voice coil soon enough  

I do think the smaller physical space between the HR and UMR drivers makes a difference in clarity for sounds that utilize those two drivers. Although I doubt this is particularly noticeable unless you’re a/b’ing the two speakers. 

The bass between the two is very similar. I need to do more listening to be able to tell a difference. 

Interesting and surprising comparison between the two models. Looking forward to getting the second completed and a/b’ing them in stereo. 

[AR surround]

On 7/3/2024 at 9:18 AM, meta_noia_fot said:

I do think the smaller physical space between the HR and UMR drivers makes a difference in clarity for sounds that utilize those two drivers. Although I doubt this is particularly noticeable unless you’re a/b’ing the two speakers. 

Big speakers require that one sits at least a certain distance from them for a properly 'integrated' sound field.  I have both AR9's and AR90's in a surround sound system.   I found that I needed to have the 90's (surrounds) at about 6 feet from my MLP in order for the sound to be integrated.   Anything placement closer than that resulted in starting to notice the individual drivers doing their thing.   But I have to wonder if integration of the sound between the LMR and the UMR is more important than that between the UMR and the tweeter.

I will be curious about your observations after you A/B the 9's and 9LSi with the repaired driver in the latter; and if moving further away from the speakers equalizes the differences.

[meta_noia_fot]

7 hours ago, AR surround said:

I found that I needed to have the 90's (surrounds) at about 6 feet from my MLP in order for the sound to be integrated.   Anything placement closer than that resulted in starting to notice the individual drivers doing their thing.   But I have to wonder if integration of the sound between the LMR and the UMR is more important than that between the UMR and the tweeter.

Unfortunately the space in my house is limited. Old house; small rooms. I was curious so I measured...my main listening position is about 7.5-8' from the front baffle of the -9's. You may be right that a greater distance from the speakers could equalize the differences between the -9 and the LSi's. But my hope and excitement about acquiring and restoring the LSi's is that they would work better in a small space than the -9's. Granted, as I've mentioned in another thread, the -9 sounds better in my small space than any other speaker I own. As another user pointed out, this is due to the design of the drivers as mentioned in the -9 manual. As it stands, I equalize the -9's bass to account for the 100hz bump and 175hz dip that are the result of the close proximity my -9's are to the outside wall (just a few inches). I was hoping I'd do less equalization with the LSi's since that placement should no longer be a problem. That may be true of the bass, but it remains to be seen if I'll need to bump up the HR range of the LSi to match the output of the -9's

I mentioned the physical space between the HR and UMR drivers because that was a revision between the -9 and the LS/LSi series; what AR called the "Dual Dome" driver. I measured here as well. The distance between the centers of the HR and UMR drivers on the -9 is 6". It's 2" on the LS/LSi.

[meta_noia_fot]

I think I'm at a reasonable stopping point on these LSi's for now, and I've spent ~20 hours listening to the LSi's and doing comparisons with the -9's.

I gave up on the Tonegen driver with the cockeyed cone. After trying five different solvents, I still couldn't get the adhesive to budge. It was getting to the point that I was seriously afraid of damaging the cone. I decided to replace that driver with the American-made 10" equivalent, part no. 200033.

As for the HR drivers, one speaker now has a new voice coil from Vintage_AR and the other has a refurbished assembly from @Chris1this1. They sound closely matched to my ear. There may be very slightly higher output from Chris's tweeter, but that could be confirmation bias as I know that he replaced the ferrofluid in that driver.

My initial impression about the high range of the LSi's still stands: highs are less present than on the -9's. A/b'ing back and forth between the two, I think the LSi sounds similar to the -9's with HR tone control set to -3db. It's not an unpleasant difference; in fact, I could see how someone might prefer the tamer highs of the LSi. Maybe when AR made the change from the -9 with tone controls to the LS/LSi without tone controls, they decided on slightly less response for the tweeter.* I do wish I could hear the difference between the LS and the LSi since I believe their crossovers are different on the HR and UMR circuits.

Bass response is very similar between the two. In my small room, the LSi performs better than the -9 without any equalization, which after all was the point of the design of the LS/LSi low range. I don't detect any boominess nor any deficiencies with the LSi compared to the -9.

I can detect very little difference between the two models with regards to the UMR and LMR drivers. Sometimes I feel like there is slightly more clarity in passages that use the -9's LMR vs. the LSi. This feels nitpicky though.

For those curious, my a/b'ing was done with vinyl as the primary source using an AT-VMN750SH cartridge fed into a Luxman LV-105u (170w/ch into 4ohms). Major caveat, of course, is that they are in my small room. Pic of the setup at the end of the post.

Both excellent speakers. The -9 is going to remain in my primary setup after I'm really finished comparing the two. I was really in the bag for the LSi hoping it would beat the -9 overall, but I think I generally prefer the HR of the -9 as well as the flexibility the tone controls provide. The LSi's will fit in nicely in my living room though.

Thanks, as always, to everyone who chimed in or answered questions while I worked on these.

-George

*It's just speculation, but I do think it's interesting comparing the -9 and LSi brochures that are in the library (the LSi brochure is under Special Sections -> AR International -> Brochures). The brochure for the -9 really hypes up how flat the frequency response is across the sonic spectrum while no such boast is made for the LSi.

[Aadams]

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

Adams

[AR surround]

1 hour ago, meta_noia_fot said:

Both excellent speakers. The -9 is going to remain in my primary setup after I'm really finished comparing the two. I was really in the bag for the LSi hoping it would beat the -9 overall, but I think I generally prefer the HR of the -9 as well as the flexibility the tone controls provide. The LSi's will fit in nicely in my living room though.

This is what is known as a "champagne problem."   Really nice job on these units, and I'm glad that you will be enjoying both pairs of speakers.

[frankmarsi]

Congratulations and all the best on a well done restoration.

Consider using in line fuses also.

FM

 

 

 

 

 

 

 

 

997

[meta_noia_fot]

Thanks for the kind words, everyone. And yes, absolutely a champagne problem.