DavidR
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Posts posted by DavidR
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@baffled_loudspeaker > could it be that the AR90 LMR/UMR and tweeter are wired out-of-phase and the 9 is not ?
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15 hours ago, baffled_loudspeaker said:
There's a second plot with the -91 just for comparison. (The AR-91 also has a different UMR crossover, but it's obviously cost-reduced)
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.
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They look very nice in the picture.
Another possible cleaner is soaking in OxyClean and rinsing. Has worked for me on curtains.
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I'll give a shout-out for Mellotone.
I used it on my Bose 901_II and they look great.
Well made material.
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Nice bike !
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On 8/21/2023 at 1:51 PM, meta_noia_fot said:
@DavidR I haven’t heard the 610’s (or any TSW speaker) but I imagine you’re right about the 91’s mid being better. The mids and tweeters from the 9 series are terrific.
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.
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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.
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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?
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On 7/21/2023 at 12:39 PM, JKent said:
Well, my E-caps came today. First impression: I'm not impressed (let the flames begin 😊). They're NPEs made in Germany with a +/-5% tolerance. I put my bundles together and here's how they measure:
- 56+33+10 "should" be 99uF. These measure 109 and 109.2. So more like 10% off
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.
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5 hours ago, Stimpy said:
Parts Connexion just changed their website. It's now Audio-Connexion. The new site isn't as easy to navigate, and it's more geared to audio equipment, and not parts. Parts Connexion now requires clicking on a link, within Audio-Connexion...! The PC site has been "updated" too, and not for the better. But, at least the same parts brands are there, they just take a little more effort to find...!
Edit: The new AC/PC site is very buggy. I can't even log into my existing account, to double-check the details of a previous parts order...!
Interesting. I wonder if Chris Johnson is still owner/president.
Thanks for the info.
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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 >>>
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10 hours ago, JKent said:
I tested them with my B&K Precision 810C Capacitance Meter. The caps "match" pretty closely, all 10% above rated value. As I said, YMMV but I'm not a fan.
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.
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12 hours ago, JKent said:
I had the same experience when I rebuilt the crossovers in my Snells. Decided to give ECaps a try, since they had been recommended by some here. Mine are all about 10% over. Probably not audible but I expected better. IIRC Dayton electrolytics are usually spot on and cost less. No more ECaps for me.
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.
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Thanks for the try Stimpy...............same issue. I was able to download it to my laptop and was able to view it.
My turn ...
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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.
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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.
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9 hours ago, blanddawg625 said:
Found the specs on the P2200.
Odd that this does not match what is in the Owner's Manual
Screen shot>
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I looked at the Audiovoxx I had in mind and the AR17 versions.
Stimpy nailed it.
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Looks like an AR speaker put out by Audiovoxx/AR.
Just a guess thou.
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19 hours ago, blanddawg625 said:
I am driving them with a restored Yamaha P2200 and Aiyima pre/DAC. The Aiyima is surprisingly quite and has a 2v output so the power is there as the amplifier is rated at 350 watts into 4ohms. I did recap these and replaced all but the 350uf on the lower board.
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
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3 hours ago, blanddawg625 said:
Sorry about the double post, but shouldn't the LMR be in phase with the woofers? This seems to make sense because this 8" driver does play the upper bass, does it not?
It is not. You'd need to ask the designers why it was done the way it is.
LMR is ~200Hz to 1200Hz IIRC
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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.
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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.
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On 7/16/2023 at 12:11 PM, blanddawg625 said:
It is because of the standing waves from the woofers which will resonate throughout the upper regions of the cabinet. The filling is there to stop this from happening.
AR-9 and AR-90 UMR crossover differences
in Acoustic Research
Posted
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.