DavidR
-
Posts
1,809 -
Joined
-
Last visited
Content Type
Profiles
Forums
Events
Posts posted by DavidR
-
-
This is the FRM-1
-
Hey Frank
MicroAcoustics was small producer of quality phono cartridges. They got into the speaker business with those Micro-Statics. I believe their next speaker was the MA FRM-1. A 10 inch woofer of good quality (don't remember the make) and a 5-tweeter array with Peerless tweeters. Almost everything else was on the cheap. They sold very well. A friend of mine gave me his pristine pair. Each speaker had a different type of stuffing and a single electrolytic cap for a crossover. I built a crossover for them and put a Miflex KPCU-1 (all copper cap) in the tweeter cap cascade bundle. I added AR stuffing from some AR94s I parted out. I use them with a tube pre and an Emotiva A-100 headphone/flex amp. Vinyl is real nice to listen to.
The sad part of the story is when they introduced their FRM-3. Bose went after them for copyright infringement as a knock-off of their 301. Happy part is they won in court and their speaker was said to sound better. Sad part is the big corporation with deep pockets and big lawyers put MicroAcoustics into bankruptcy. That was the end.
-
Nice, neat work.
-
Over the years toluene has had its permissible exposure level continually reduced. Not good for your central nervous system, blood, heart, etc. BUT being an aliphatic it smells nice.
-
On 3/11/2024 at 12:28 PM, baffled_loudspeaker said:
The seller used M-3035 adhesive. Do you know what could dilute it?
Also, you're sure there's a masonite ring under the outer edge of the surround on the 12" AR-9 woofer? It's not just bonded to the metal basket?
Thanks again.
Toluene will work well. Wear nitrile gloves. Toluene will pull fat from your body right thru your skin.
Attached is a picture of my AR91 woofer that shows the masonite ring.
-
Yeah, Boston would have worked. Shipping is crazy expensive at the moment.
Let us know if you find out about the glue used.
Be careful not to destroy the masonite ring on the outer edge (under) of the surround. A good sharp exacto blade might cut the glue on the surround edge glued to the cone. Just take your time.
-
See if the person you bought them from remembers what glue he used. Acetone is not a typical diluent for adhesives. I work for a large company that did lots of adhesives. Lacquer thinner, toluene and MEK might be better - BUT it all depends on the glue used. Use a well ventilated area to do any work with those solvents.
Where do you live? If you are close I'd be willing to take that on for you.
-
The metal cased canned cap behind the autotransformer might be a Callins cap. They did not use the same liquid electrolyte as Sprague and probably not the same quality winding material.
These should be checked/tested. I have MkII 10Pi and all the caps were Callins and needed replacing.
Congrats on acquiring a great pair of speakers.
-
On 2/24/2024 at 12:01 PM, Gaston said:
I would love to hear from someone that has done this kind of comparison with AR's with 12" LF driver. I have a pair or AR-3a and AR-11, but I cannot find a friend that has a comparable modern speaker...
B&W 685 S2 data:
I was comparing the B&W 802 to my 9s and 90s. I wouldn't bother to listen to a small two-way speaker.
-
15 hours ago, genek said:
No, I can see how today's 6.5" woofers in a properly designed cabinet might outdo 50-year old 8" woofers.
That is not what I was referring to. Perhaps I misunderstood your comment.
-
1 hour ago, genek said:
No way is a pair of two-ways with 6" woofers going to do it by themselves.
or even 8 inch woofers.
-
6 hours ago, Gaston said:
B&W's had better, tighter, deeper, more pronounced low frequencies... even though the LF driver is smaller, they easily outclassed AR's with bass.
- Surprisingly, AR's mid and higher frequencies reproduction was way way way (that's 3 times
) better than B&W's. The details were incomparable. B&W's sounded muted with some sounds obscured and were incomparably better reproduced and revealed by AR's which sound was full with air and presence.
I have listened to several B&W speakers and Martin Logan. I have the exact opposite opinion of the B&W. I find the tweeters exceptionally clear and precise, the mids are nice but nothing stands out as special and the bass is weak. I have listened to them being driven by a high-end solid state amp (Bryston) and big McIntosh mono tube amps. I was always un-impressed with the B&W bass. The ML were driven by McIntosh 275 tube amp. If you moved an inch off center you'd lose stereo and everything falls apart. On center they are clear but no big wow factor for me.
I always felt the AR upper end needs improvement compared to today's speakers. I find that the male voice (not singing but talking) is poorly reproduced. As for the bass when comparing them to my Bose 901_II > The Bose shake the walls but the AR bass runs down thru the frame of the house. The Bose bass is more baritone and AR is true bass.
My AR speakers for comparison are 9 and 90. Even the bass from my 10 Pi and 91's and son's TSW610 are very deep and well defined.
-
Craig's List in Natick, MA (about 12 west of Boston)
Original 1955 Acoustic Research model 1U in unmolested condition. All original. The U stands for unfinished. Tested and sounds great! The box is not in great condition but if you are familiar with this speaker that is irrelevant as the value is in the drivers. The 755a routinely sells for $2000 and the woofer for $400.
It is hooked up and can be tested before purchase. Removing the drivers can be tricky and I don’t have the time and I don’t want to risk damaging them doing it myself. If you have the time and experience to part this out there is $900 worth of profit for you….
This is an early model with the 7 binding posts, address of 25 Thorndike not 24 and low serial number 1814.
Price is extremely firm! $1500 -
Try this guy > http://www.millersound.net/about.htm
-
I wonder which AR brand owner made these.
-
As a tube amp owner I would think a bass reflex design (ported) with a tube amp which typically have very low damping factor would sound very wooly and flabby with little 'tight' bass sound. For a while I ran AR91 with a solid state amp that had very high damping factor and 10Pi with my tube amp. VERY different bass sound.
Those speakers are not listed on the Aphenos list.
To each his own.
-
Mine are walnut.
-
Will you ship if we arrange for shipping and insurance?
-
I just found a schematic for the 3a Improved. It has all drivers in phase. BUT, it has no info on who made it so can't vouch for it being correct.
-
The schematic I have shows the AR11 tweeter is out-of-phase.
-
I use my stereo receiver and put a 4uF capacitor on the plus side wire that would go to the appropriate driver terminal. It should filter out any low frequencies.
-
FWIW: There is an AR1Wu for sale on Craig's List in Arlington, MA just outside of Boston.
-
I think the cabinets look great with the darker stain.
-
On 10/12/2023 at 5:54 PM, baffled_loudspeaker said:
9 schematic has the tweeter, UMR, and LMR transducers wired in opposite phase from the AR-90
The 90 is wired out of phase. The 9 is wired in phase, same as the woofers.
Just didn't know if that might account for your query re. 90 UMR not the same as the 9 in your 'sweep' - don't really think so but thought I'd throw it out there.
Another question for you: Are the UMRs all p/n 200028 in both sets of speakers? Sometimes they get swapped out for p/n 200032 as used in the 91 and other speakers; and then there's the 200044 UMR/Mid.
)
Steve Feinstein has passed away.
in News
Posted
Steve wrote some of the best and interesting posts here on CSP. He had a lot of insight on many audio topics. So sad.
Sorry for your loss Ella. It's our loss as well.