AR 9 Crossover Rebuild

[Stimpy]

6 hours ago, brianw said:

So we have been listening to the AR 9's for a while with the CAP's replaced.  Used Mundorf  MCap Aluminum oil.  Extremely smooth, flat and clean, sometimes to flat.  After a few months of listening we quite often feel like there is a vale in front of the high end.  Often wanting to hear a little more openness, sparkle and air from the top end.  Have adjusted EQ and tend to push the mids / high end up a few DB.  So is this a choice of caps in the upper mid's, and tweeter as I have read several articles both on this board and others referring to different cap  brands producing different  results ?

As far as the bottom end, the two 12 woofers, I am being told to remove the large capacitors, 2500.00 and 470.  Anyone have any thoughts and hookup methods.  

 

I went with Mundorf EVO Oil poly caps for my AR90s as well.  I used the EVO Oils on all the series caps.  I used Axon polys for the parallel caps, except the 350uF.  That's a Mundorf E-Cap and an Axon in parallel.  The tweeter, UMR dome, and LMR woofer also have Mundorf Supreme bypass caps.  A bit of money, but worth it to me.

As DavidR and AR Surround often remind me, I need to complete my AR90 refurb, so I can give my recap a true evaluation.  So far, just QC listening checks, during the crossover rebuilds.  But, I found the Mundorf's very clean, clear and open sounding.  Very good presence too.  The stock crossover sounded muted and veiled in comparison.  Very distorted sounding.  Static crackle type of noise.

As an experiment, when I recapped my AR58S speakers, I used ClarityCap poly caps.  CSA's on the tweeter, and ESA's on the dome midrange.  Shunts were Bennic NPE's with Dayton F&F bypass caps all around.  I wanted something different, and something that I could compare to the Mundorf 90's.  The Clarty's took a long time to break in.  Flat and muted at first.  Very sucked out in the upper mids.  That took weeks to clear up.  Adding the bypass caps helped.  Now, warmer and more mellow than the Mundorf's (and Dayton's that I've tried).  Maybe richer sounding, but not as dynamic.  Good, natural sounding detail.  I still like the Mundorf's better, though the ClarityCaps are very nice.

Oh, finally, I personally recommend leaving both the 470 and 2500 woofers caps.  The 470 cap is part of the woofer 2nd order crossover circuit.  Plus, the 2500 not only bumps the woofer impedance, it's also part of a woofer EQ circuit.  Tweak/remove at your own risk.

[DavidR]

1 hour ago, Stimpy said:

As DavidR and AR Surround often remind me, I need to complete my AR90 refurb, so I can give my recap a true evaluation.

I just might get my 9 cabinets restored, xovers recapped AND my 90's recapped first (bad back and all - hoping the cortisone shots bring relief).

[Stimpy]

9 minutes ago, DavidR said:

I just might get my 9 cabinets restored, xovers recapped AND my 90's recapped first (bad back and all - hoping the cortisone shots bring relief).

Oh be quiet.  And if the AR58S speakers weren't so good, I'd be more motivated to finish the 90s.

Good luck with the shots.  My Doctor won't give me any more.  My last MRI was too bad.  Now, I do my yoga, and keep on limping.

 

[DavidR]

On 12/9/2017 at 8:58 PM, harry398 said:

I just picked up a set of ar90''s

They sounded terrible when I brought them home.   

I recapped them today, what a huge difference.    Now smooth,detailed and just flat out awesome in the living room. 

I used auden poly on tweeter circuit, and plain Dayton NPE everywhere else with .01 poly bypass on mid and mid bass circuit.

The Parts Express NPE caps are made by Solen in Canada. They measure all over the place but within the +/- 10% tolerance.

Madisound is dropping the Bennic NPE and replacing them with MDL.

[AR surround]

I'm still very happy with the Mundorf ECap with Dayton F&F bypass for the 24uF series circuit on the AR9 and AR90 UMR.    However, I did go into the AR90's again this past January to add more series resistance to the tweeter and UMR circuits.  Total possible attenuation resistance for tweeter is now 3.1 ohms vs. 5 ohms stock.   Total possible attenuation resistance for the UMR is now 3.5 ohms vs. 4 ohms stock.   In retrospect, I probably should have just left the attenuation network on the AR90 as stock.

[brianw]

Well,  first thanks everybody for replying so quickly and with so much information, thank you.

So a little further explanation.  ALL the caps in the AR 9 were replaced,  Mundorf  MCap EVO Oil for Tweeter and Upper Midrange.   Used AXON for the Lower Midrange.

TWEETER CIRCUIT  (Mundorf EVO Oil)
The 4 uF, 6uF in the high Tweeter circuit. 
Used EVO Oil 3.3 + 2.7 for the 6uF
Used EVO Oil 3.9  for the 4uF
(Original 6uF had drifted to 27.9.  Original 4uF was 5.7 )

UPPER MID RANGE (Mundorf EVO Oil)
The 8uF,  24uF and 40 uF UMR 
Used EVO OIl 8.2 for the 8uF
Used EVO Oil 15 + 8.2 for the 24 uF
Used EVO OIl  18 + 18 + 3.3 + .68  for the 40uF
( Original 40uF was now 52.7. Original 24 was now 28.4 )

LOWER MIDRANGE  ( AXOM )
The 30uF and 80 uF in LMR 
Used 30uF AXOM for the 30uF
Used 39 + 41 AXOM for the 80 uF
( Original 30 was now 32.1.  Original 80 was now 95.7 ) 

 

Couple of links of interest.
http://www.humblehomemadehifi.com/Cap.html

http://www.humblehomemadehifi.com/download/Humble Homemade Hifi_Cap-Test-Ratings.pdf

http://www.thlaudio.com/solncitmE.htm

NO doubt the sound is WOW clean and amazing, what I am understanding is to get that open airy sparkle I need to jumper the tweeter, UMR and lower midrange with teflon caps, anyone have any thoughts.

Brian

 

 

 

 

[harry398]

On 11/7/2018 at 9:58 PM, DavidR said:

The Parts Express NPE caps are made by MDL (Taiwan). They measure all over the place but within the +/- 10% tolerance.

Madisound is dropping the Bennic NPE and replacing them with MDL.

you may have had some bad batches or thats how they are.

 

all I can say is they are the BEST sounding caps i have tried....and I almost sold the ar9lsi because of those yellow turd caps that were in them   horrible sound.

 

polys?   if in mid circuit, they will be harsh/edgy.   I have tried......some speakers are more sensitive to poly than others, but I will Never put a poly in a mid circuit again.

 

as of now, the ar9 and ar9lsi are neck and neck in sound quality, with slightly different tones.   all dayton npe caps.

 

simply amazing.    Nothing is even close.   And I own 2 x ar3a, ar58s, 3x  ar98ls, ar98lsi, ar50 among others.   All of these are excellent, but not even close  in clarity and total package to the 9 series.    the biggest bargains on top of it..

 

Dayton cheap caps.    awesome.     Everyone can do their own testing and justify/rationalize  their own purchase price.   I tried, the cheapies sound best.

[ra.ra]

18 hours ago, harry398 said:

simply amazing......Dayton cheap caps.......awesome.......Everyone can do their own testing and justify/rationalize  their own purchase price....I tried, the cheapies sound best.

Wow!.....after reading all about the virtues of the costly capacitor brands running into the hundreds of dollars, this is a very strong and refreshing testimonial on behalf of the much-maligned NPE cap, which is probably not all that dissimilar from what the original designers used at the factory. "Different strokes for different folks", I suppose, but it's really good to see an endorsement of a simple and inexpensive solution that resulted in very gratifying results.

On 11/7/2018 at 9:58 PM, DavidR said:

The Parts Express NPE caps ....... They measure all over the place but within the +/- 10% tolerance.

Not sure I understand this statement. If these caps are noted as 10% tolerance and they all measure as such, aren't you getting this product "as advertised"? How can this be construed as "all over the place" if they measure within the stated spec? 

[DavidR]

3 hours ago, ra.ra said:

Not sure I understand this statement. If these caps are noted as 10% tolerance and they all measure as such, aren't you getting this product "as advertised"? How can this be construed as "all over the place" if they measure within the stated spec? 

Yes they were within the 10% tolerence. I still have the readings from some 220uF caps and they measured: 199, 206, 214,231. To me that's all over the place. I had other values with similar results. However, the 250uFs all measured 248uF.

[ra.ra]

5 hours ago, DavidR said:

Yes they were within the 10% tolerence.

That's really the only point I was trying to make. You know far more about this than me, but I'd suggest that if the outer limits of the stated 10% variation are going to be unacceptable, one might want to pay for the "matching" service that several purveyors offer to ensure more consistent measurements. I fully agree that measuring is important, and it is clear to me that your personal criteria for cap selection is far more stringent, nuanced, focused, and particular than are the selections I make for my own humble projects. That's all OK - - no real bone to pick - - but I do sometimes question the expense involved in some of these re-cap "upgrades", which is why I was delighted to see harry398's report from his experience. 

[DavidR]

Parts Connextion is excellent at matching for a dollar per pair. They are within a 10th or so (first decimal place) per pair. Nobody does a better job at matching.

Madisound charges a dollar per cap and will get within 1% of each other (most of the time).

Parts Express does not offer matching.

I'm fussy about having tweeter and mids within 1% of each other - a pointer Carl passed on to me.

[ra.ra]

On 11/13/2018 at 7:50 PM, DavidR said:

Parts Connextion..... Madisound........Parts Express....

All very good sources.... thanx for the tips. FWIW, here's another supplier (also from Canada) that I sometimes like to use. They have several lines of Solen caps you cannot find at other places (most are $$$ expensive....sigh...) as well as everyone's favorite and reliable Dayton caps. While their overall product line is somewhat selective and limited, I particularly like the very affordable LYNK MOX resistors.

https://solen.ca/

[Stimpy]

Sonic Craft offers parts matching too.  Matching tighter than factory tolerances, if desired.  On both NPE's and poly's.  I used them for my last cap order, and had them match all parts.  While I couldn't test them, it made me happier, just the same.

[AR surround]

On 11/8/2018 at 12:13 AM, brianw said:

Well,  first thanks everybody for replying so quickly and with so much information, thank you.

So a little further explanation.  ALL the caps in the AR 9 were replaced,  Mundorf  MCap EVO Oil for Tweeter and Upper Midrange.   Used AXON for the Lower Midrange.

...UPPER MID RANGE (Mundorf EVO Oil)
The 8uF,  24uF and 40 uF UMR 
Used EVO OIl 8.2 for the 8uF
Used EVO Oil 15 + 8.2 for the 24 uF
Used EVO OIl  18 + 18 + 3.3 + .68  for the 40uF
( Original 40uF was now 52.7. Original 24 was now 28.4 )...

...NO doubt the sound is WOW clean and amazing, what I am understanding is to get that open airy sparkle I need to jumper the tweeter, UMR and lower midrange with teflon caps, anyone have any thoughts.

Brian

 

Glad to hear that you are pleased.  Couple of things:

- Are you getting any glare / harshness from the UMR?  How about noise?  Poly caps on the UMR series cap (24uF) were a disaster for me, so I went with Mundorf ECap on that one.

- I used Dayton F&F bypass caps across the poly caps as well as the ECap.   Others have used Vishay and others as bypasses.   DavidR has some info on these.   The F&F bypass across the NPE's took out the last bit of grunge from the sound.

 

[brianw]

HI AR Surround

 

So for the slow reply, caught up in the season and demands on my time.

I get no harshness or glare from the UMR at all.  And seriously no noise, just clean.  I am driving the AR 9's with a Bryston 4B ST  Power AMP with lots of headroom, a conservative 350 Watts per channel.   www.bryston.com 

What I found is everything is so clean that depending on the source the 9's sometimes sound like they have a bit of a vale or blanket over them.  The tweeters are working but I am wondering how well, possibly the efficiency has dropped. As I have sometime boosted the 6K to 16K range by a 1.5 DB in the Marantz Av-7005 preamp  equalizer.

Go with the mundorfs EVo Oil

[brianw]

So my next question is with all the high end electronics ;

2 x Bryston 4B ST Power AMPS
1 X Bryston 3B ST Power Amp
1 x Marantz AV-7005 pre amp
1 x OPO BRP-103

We still find the AR 9's have a lack of openness, or much like a thin blanket over the speakers. This of course varies with source but seems to be present.  

Anyone have any thoughts on bypass capacitors, possible tweeter issues or do we need to make a tweak to the crossover to eliminate that roll off of the upper frequencies. Maybe someone can explain or offer suggestions that would be great.   I have also been told that the Marantz preamp will soften the sound of everything and even though it is a high unit tends to be quoted as a soft sound ??

Cheers to everyone and a Happy, Healthy New Year.

Brian

 

 

 

 

[ar_pro]

We still find the AR 9's have a lack of openness, or much like a thin blanket over the speakers. This of course varies with source but seems to be present.

Does your Oppo player have a volume control that would allow you to connect it directly to your amplifier without using the Marantz AV preamp?

A passive preamp, or no preamplifier can sometimes provide that last little bit of clarity. 

[Stimpy]

20 hours ago, brianw said:

We still find the AR 9's have a lack of openness, or much like a thin blanket over the speakers. This of course varies with source but seems to be present.  

Anyone have any thoughts on bypass capacitors, possible tweeter issues or do we need to make a tweak to the crossover to eliminate that roll off of the upper frequencies.

Personally, I think your speaker issues, are more to do with system equipment, than with capacitor or speaker problems.  Let me explain.

Years ago, in another life, I worked in audio.  Specifically, I worked at the largest independent CD replication pressing plant in the world.  Over 30 pressing lines.  We manufactured CD, CD-Rom, DVD, and xBox discs.  While there, I worked 6 years manning the master cutting lathes, and another 9 years in the audio mastering departments. The mastering area had 2 almost identical audio suites.  The same size and layout, with matching gear and Tannoy monitors.  The only differences were in the power amps (not sure how that happened).  My suite used a Hafler P500 amp, and the other suite used a Bryston 4B amp.

Well one day, the other engineer was out.  So I was working in both suites; doing master transfers, transcoding PQ Subcode TOC metadata, and listening to QC Test Press samples.  In running back and forth between rooms, I started noticing sound differences between the systems.  Weird, as I wasn't expecting that.  The Hafler suite sounded warm and natural.  Upper mid and treble response was open and clear, with nice bloom and air.  The Bryston room, while maybe more accurate in sound, sounded "off".  Flat and a bit lifeless.  The treble was very bland and dry.  No bloom at all, not like with the Hafler.  The treble almost seemed sucked-out, since it was so closed in.

Adding bypass caps might help with your issue.  They do help add some sparkle.  I've personally used Dayton Film & Foil bypass caps.  With the EVO Oils, on my 90's, I added Auricaps, to the 2 treble caps.  My 90's do not sound veiled, or lack openness.  But, I also use a Hafler D500 amp!  I'm truly not knocking your Bryston, though I'd suggest trying to audition another amp with your 9's.  There might not be a need to tear into them?

Good luck.

[DavidR]

On 1/18/2019 at 10:39 PM, brianw said:

We still find the AR 9's have a lack of openness, or much like a thin blanket over the speakers. This of course varies with source but seems to be present.  

Dried ferro-fluid comes to mind and I think AR_Pro might be on to something. I find the Pre makes just as big of a difference in sound as an amp - some times more so.

On 11/8/2018 at 12:13 AM, brianw said:

what I am understanding is to get that open airy sparkle I need to jumper the tweeter, UMR and lower midrange with teflon caps, anyone have any thoughts.

Brian

I've never tried teflon but it is supposed to be the 'best' film. They are expensive even for small value caps. I have read that polySTYRENE compliment polyPROPYLENE very nicely. JBL used to use small value PS with a PP base cap in their higher end speakers. I bought a pair of 5000pF 600V  RTE polystyrene for my nines and will put them on the 6uF or the 4uF cap. I chose Clarity CSA with AudioCap Theta bypass caps for the tweeter and Clarity CSA + Cornell-Dublier 940C bypass caps for the mid series cap. This combo worked out nicely on my 91s.

On 1/19/2019 at 4:28 PM, Stimpy said:

I've personally used Dayton Film & Foil bypass caps.  With the EVO Oils, on my 90's, I added Auricaps, to the 2 treble caps.  My 90's do not sound veiled, or lack openness. 

So you have your 90s up and operational? ?

[Stimpy]

20 minutes ago, DavidR said:

So you have your 90s up and operational? ?

Well, they are standing up...!  Now, define operational?  

[DavidR]

op·er·a·tion·al

[ˌäpəˈrāSH(ə)n(ə)l]

 

 

ADJECTIVE

1. in or ready for use.

   "the new laboratory is fully operational"

   synonyms:

   up and running · running · working · functioning · operative · in operation · in use · in action · going · in working order · workable · serviceable · functional · usable · viable · ready for action · prepared

[Stimpy]

Synonyms for operational:  serviceable. 

That works.  

[cd0nc]

I just finished putting mostly films caps in my AR9LS speakers whilst doing the LSI mod, having done a lot of reading this time, at least compared to when I did my AR90s.

After finishing one of the pair, I compared the modded and pre-modded. I couldn't tell much difference aside from the brighter top-end. When both were complete, they initially sounded very bright (louder in the top end) and sibilant. This seems to have died down somewhat with several hours run-in (or I've gotten used to it). One of my ears is ringing on and off from the medication I'm on, so I might not be in the best place to pass judgement yet anyway.

I also compared the 9's to the 98LS which I too had modded to LSI specs. I used NPEs for the 98s, aside from a single 3uf Solen film on the HR. They sounded very, very similar aside from lack of bass extension and the 9's having a louder (for want of a better word) mid to top end. The 98s sounded less sibilant, perhaps due to not having a film cap on the dome UMR. The 3uf Solen HR 98LSI HR is OK to my ears but the 3uf Jenzen crosscap on the 9LSI HR is questionable until I get to the source of the sibilance. 

I've heard varying reports of ESR in NPEs putting resistance in the circuit so perhaps this is why the 9s are louder. Unfortunately I only have a basic capacitor meter so I can't confirm this.

I can say that the Unicon caps in the 9LS's were almost all totally within spec, perhaps aside from the largest (470uf)capacitor. The values were basically spot on, more so than the replacements! I also wasn't put off by the initial LS sound after I did the refoam work either. I think it is important to check values before replacing, if I had not bought replacements before checking, I likely would have left them alone a little longer.

Personally, I don't think film caps have made an improvement to the sound in my case. Although they don't sound any worse, I personally won't be getting excited about buying film caps in the future. 

Having put mostly Bennic NPEs and a couple of Carli mylars for just the UMR and LMR shunt in my AR90s, I think they are currently the least fatiguing combination to my ears. Perhaps any distortion/resistance matches how they were designed to sound originally, which I imagine was driven by the human ear, rather than specification sheets and computer simulations.

It should be noted that I haven't tried more expensive film or bypass caps so my opinion might change one day. Resistor type and coil orientations are also apparently up for debate.

I can see the appeal of film caps, as I technically shouldn't have to do much to my crossovers for a while. If you like tweaking components, have enough money and time to do so, then it's likely good fun changing out caps until you reach a combination which suit your own ears the best.

Before / After - 9LS / 9LSI

[DavidR]

On 1/20/2019 at 1:44 PM, cd0nc said:

I can say that the Unicon caps in the 9LS's were almost all totally within spec, perhaps aside from the largest (470uf)capacitor. The values were basically spot on, more so than the replacements!

Amazing considering their age.

Did you measure them at 1kHz?

[harry398]

The unicorns may test on the gauge well, but their sound isnt always as good as new dayton NPE.  I have done 6 sets in that series.  The sound is the ultimate test.

I have a set of ar9ls I just picked up, and slapped drivers in it, moved some polyfil around and slapped a 3.3 ohm resister in the mid circuit, and its damn good, but I can hear old caps.......

The LS series is nearly the best sounding, flattest curve and most detail of all AR speakers, once you do enough mods to get them right.   The Bass detail in My ar9lsi is incredible, blows away the ar9 in that respect. 

My AR9lsi is now about perfect.   I will also say STIMPY is spot on with amps affecting sound.   My ar9lsi gave me headaches......from hating them when I got them, to now being superior to the ar9 in detail and overall presentation to the AR9.  Thats right, after I switched from the carver tfm 42 (which works great with my AR9) to a carver 4.0, the AR9lsi is now about perfection............   The soundstage in the ar9lsi is Incredible.   wide and full.  They were dark and and boomy with the tfm 42, NOT with the carver 4.0.    AMPS change the sound.

 

alot of work, experimenting on that speaker.  

 

As for veiled AR9's......mine arent, not at all.   something is wrong.   They are open and clear.   The AR9 is clearer than the AR9lsi, now only marginally, but they are the clearest speaker I have owned.  They also go a tickle lower in bass freq than the AR9lsi

Making changes sometimes takes you forward, other times backward........so Brian, revert back a few steps....if you care to find the problem and definitely change the amp to form a baseline.

 

Happy New Year to all.........enjoy the music.