DavidR

It's a slightly different driver; able to reach lower. IIRC its p/n 200028 for the 9 and 90 and 200032 on the 91. There was no need for the notch filter that is on the 9 and 90 models.

They look very nice in the picture. Another possible cleaner is soaking in OxyClean and rinsing. Has worked for me on curtains.

I'll give a shout-out for Mellotone. I used it on my Bose 901_II and they look great. Well made material.

Nice bike !

A few years back we did a side by side comparison. Not both at the same time but Speakers-A and Speakers-B: merely a flip of the switch. Stimpy is correct about the tweeter. It was hard to decide which was better. The TSW was a bit brighter but not in a bad way. It came down to personal preference. My son preferred the 610 tweeter but I preferred the 91s. The 91s blew the mids away of the 610 as I said. The bass was very close but the 91s were a tad better; more deep, rich, and full-bodied sound. The 610s are no slouch.

Great find. I like my 91s, too. Been trying to get my son to take them and replace the TSW610s. The mid in the 91s blow away the cone mid of the 610s.

Most of the NPE caps I've purchased from Parts Express have measured (@1000Hz) quite well EXCEPT the 220uF. Althou still in spec of the +/- 10% tolerance most of them measured 15uF low; some lower some a little higher. I'm still willing to measure your Ecaps caps and send them back free of charge. Some years ago I got some that measured high. Not sure of the value but they were relatively small value caps. I wrote (email) to Mundorf who responded that this particular value had been incorrectly set up on the machine that manufacturers them and that the issue had been corrected. They sent me new ones. Where was the QA department?

It's the meter. They probably did measure 10% high because your particular meter has a pre-selected frequency based on cap size. It measured them at 8.2Hz instead of 1000Hz. We know from Carl's posts and measurements that NPEs rise in capacitance with a decrease in frequency, and conversely, decrease in capacitance with an increase in frequency. Any NPE would do this. Carl also demonstrated that film cap capacitance is barely affected, if at all, by frequency. Perhaps this is why I find that speakers designed with a crossover using NPE sound 'right' with NPE vs dropping film caps in. Ken Kantor always said to replace like with like.

Interesting. I wonder if Chris Johnson is still owner/president. Thanks for the info.

I looked up the manual for your unit on the B&K website. Here is a screen shot and the reason for why they measure high - pre-selected test frequency is too low >>>

Not what I asked. What frequency did you use when doing the test? If you want send them to me and I can measure them and label them and send them back to you free of charge. PM me if interested. Also, if they are 10% high then P.C. will correct the problem. So will Mundorf - free of charge.

Did you test them at 1000 Hz ? You can also request a matched pair for a $1 My LCR always matches what they write for a value on the bag within a tenth of a uF.

Thanks for the try Stimpy...............same issue. I was able to download it to my laptop and was able to view it. My turn ... G.Short BYPASS white paper.docx

Not sure the pdf link is working. All I get is a blank screen. North Creek was owned and started by George E. Short III. He made several lines of capacitors including the bypass caps and a line of speakers. I'm told they were very good caps. He was an audio engineer at Acoustic Research for a period of time.

In case you don't have one here is a pdf of the AR90 Owner's Manual. There is a graph of the frequency response showing the ohms levels. AR90 Owners manual.pdf

Odd that this does not match what is in the Owner's Manual Screen shot>

I looked at the Audiovoxx I had in mind and the AR17 versions. Stimpy nailed it.

Looks like an AR speaker put out by Audiovoxx/AR. Just a guess thou.

I didn't see where this amp is spec'd for 4 ohm operation. I could have missed it. There is a link to the Owners Manual at the bottom of the page. This was a fine amp in its day. Today's current pushing amps do a better job with difficult loads IMO. http://www.advancedaudiorentals.com/products/details/productid/148

It is not. You'd need to ask the designers why it was done the way it is. LMR is ~200Hz to 1200Hz IIRC

The tweeter, UMR and LMR are wired out of phase and the woofers are wired in phased. Just look at the wiring schematic. The series cap (+) is wired to the negative side of the drivers. This is different than the AR9 where all drivers are wired in phase.

What are you driving them with (amp and pre) ? Caps can affect the bass and in my case the LMR recap made a noticeable difference.

Kent, that list looks like a good way to tackle the cap replacement. $9.50 for Mills !!!!!! Wow, they have doubled in price ! I have a few of the Mundorf resistors but have not used any (yet) so I can't comment. I do know of several people who have used them and no complaints. Some may find these write ups on Peter Snell interesting. https://auralhifi.com/pages/snell https://www.stereophile.com/content/snell-type-loudspeaker-peter-snell-1946ndash1984

Snell made some fine speakers. One thing they were known for was bundling caps. This was for two reasons: (1) to reach a particular uF and (2) to attain a particular ESR (equivalent series resistance). You might find that the bundle of caps in one speaker do not match what's in the other.