AR90 vs. Boston Acoustics T1030 vs. AR Holographic Imaging M6

[Dan Mui]

I finally decided to write my experience with my current three pairs of speakers. I am not audiophile but a serious listener. Most of my music is from the 70’s soft rock to classical acoustic music. They are all driven by two Sony STR-DA7100es Class D amplifiers and 2 Denon DVD-2900 players.

1. Acoustic Research AR90 bought new in early 1982. I replaced all 6 drivers (4-10” & 2-8”) with foam surrounds. One 10” driver needed to be replaced by supposing AR driver from then A-B Tech after a couple years of coil rubbing (after new surround). I added Optimus Linaeum tweeters on top to get better highs (40-1389).

2. Boston Acoustics T1030 bought used in 2018 late summer in excellent condition. I was planning to get KEF Reference Model 3 (or KEF similar) but none were available. I read the glorious Audio Magazine review for the BA T1030 and a pair was locally available. All new surrounds done in 2016 or so by previous owner. I added Optimus Linaeum tweeters (40-1389) as well. I still want to get a pair of KEF just to try out eventually.

3. AR Holographic Imaging M6 in fair condition. I replaced all 4-8” (210mm) woofers with rubber instead of the original foam. Repainted with 7 to 8 layers of spread paint in light flat Black (more like dark charcoal grey) for the cabinets. I think the bass comes from a band-pass design similar to KEF in the late 80’s.

Sound Quality:

Of the three pairs, the most balance sound comes from my AR90 with the Linaeum tweeters. Without the Optimus Linaeum tweeters, the sound is somewhat recessed and confined within the cabinets. It also lacks depth by itself without the Linaeum tweeters. Being a dipole, the tweeters also produce wide dispersion of high frequencies. The bass can go low but not very tight. I believe that this is because they can reproduce lower frequency well and is distracting it from the tightness. An increase in overall volume would help to tighten up the bass noticeably. AR90 has the advantage of being a 4-way design to achieve the most balance sound. The 8” lower midrange seems to achieve that goal well. Midrange appears to be a bit cloudier than both AR HI M6 & BA T1030. All in all, they are still very good speakers. However, they are not the most accurate speakers of the three above.

BA T1030 are the most accurate speakers to my ears. They are similar to the AR90 but seem to be even more natural with piano and vocals (somewhat less accented). Their

bass are strong, tight but not as low as the AR90. Vocals are very good & a bit less accented & less bright than the AR90. The seller/owner has a pair of older Harbeth 40 for music. He demonstrated them to me after the sale. Vocals were even better and more solid than the T1030 but the musical instruments sometime became too “dark”. I am sure that they sounded more correct and accurate but they sounded sometimes less “attractive” than the T1030. I sometime can hear a bit of plastic (plastic vs. paper woofers) sound coming out from the T1030 woofers when driven louder.

AR HI M6s are truly holographic speakers. I can’t say whether they are correct in the sense of space and imaging but they do the trick very well. They sound nearly without the speaker box boundary. Bass is very strong and tight but not as low as the AR 90. I would say that the lower bass limit is similar to the BA T1030. Midrange is clean & clear but sound a tiny bit like a speaker phone. The band-pass design crosses over at 150 Hz for the 2-8” woofers (in each cabinet). Maybe it is because the lower crossover frequency, I hear an upper bass discontinuity. It is not noticeable when playing by themselves, but since they are parked next to my AR 90, the discontinuity is evident. Switching them back & forth can pin point that rather easily. I also hear a tiny bit of metallic sound coming out from the tweeters. These are “bright” enough that I don’t need to add the linaeum tweeters. If the recording is recorded without aggressive brightness, I can tolerate them but just about the maximum limit. However, I listen to my AR 90 more because they are easier to listen to for a longer period of time. This is also very similar to Boston T1030 without listening fatigue.

Other speakers that I had were Martin Logan CLS (driven by ARC amplifier D90), Carver Amazing Speakers (ARC amplifier D90) and Polk Audio SDA-1c.

Thank you!

Dan

[Stimpy]

Welcome Dan,

I enjoyed your comparison and write up.  But, I know from experience, you also need to consider recapping your AR90s, to bring them up to date.  Many here, myself included, have found failed capacitors in our AR9s and AR90s.  Capacitors that tested grossly out of spec.  I bet after a recap, the few negative performance aspects that you've noted on your 90s, would largely disappear.  Electrolytic or poly caps are acceptable.  Match the capacitance as closely as possible, while voltages can be higher, without issue (other than the cap size can increase, the higher the voltage).

Thanks again.

[Dan Mui]

Stimpy,

That is always in my mind (for last few years) but the Linaeum tweeters really help.  They outperform both AR90 & T1030 tweeters abd best with acoustic music.

[Dan Mui]

Stimpy,

Thank You!

[briodo]

Agree with Stimpy, the cap degradation impacts the sound in ways it is hard to describe.  15 years ago I was ready to sell my AR9's due to poor sound quality.  Then I found this forum.  They are back to my favorites.

While adding a tweeter can help with a specific frequency band, there is a lot of excitement in the bands covered by the upper and lower midranges, which is where things can become what I would call muddy.  The cap replacement ensures they are back to original spec.