nOrh 9.0 speakers "fixed" by Dennis Murphy!

droliver · « **Reply #20 on:** 3 Jan 2004, 11:08 pm »

I'd be curious as well on a mod available for the SM 6.9 which I own. I just noticed on Audiogon that all the Norh marble drums usually up for sale are gone. I wonder if this thread has stimulated a little run on them? I hope so as I think I'm going to post my 6.9's for sale. They're pretty solid speakers I think & they've always sounded great to me, they're just not my wife's favorite & I've been unable to stand mount them around the kids.

Oh yeah..... It'd be nice to hear from Mike Barnes again around here about this and Norh in general! He always was a very straight shooter with me when I bought & later upgraded some Norh's 3 years ago & I miss the kind of hovering customer service he used to provide on Harmonic Discord & here

MaxCast · « **Reply #21 on:** 4 Jan 2004, 01:29 am »

Thanks for the info, guys. If anyone hears about the 6.9 LMK. I don't have enough $$ for a speaker upgrade so I will have these for a while yet.

If I remember right the xo is on a larger that 5" board so removal of the baffle may be in order.

nathanm · « **Reply #22 on:** 4 Jan 2004, 02:01 am »

I would keep the crossover in a breakout box myself if I were to go with the DIY Murphy crossover. That way you have to fuss inside the cramped dark drum just once. Hardwire the drivers to the binding posts and be done with it. Maybe build a box that doubled as an under-speaker platform.

Ravi · « **Reply #23 on:** 4 Jan 2004, 02:12 am »

Great idea Nathan. Make a nice wooden case for the XO. You could even out the XO's in your audio rack, or between the speakers and the stands.

DeanSheen · « **Reply #24 on:** 4 Jan 2004, 05:24 am »

Quote from: MaxCast

Thanks for the info, guys. If anyone hears about the 6.9 LMK. I don't have enough $$ for a speaker upgrade so I will have these for a while yet.

If I remember right the xo is on a larger that 5" board so removal of the baffle may be in order.

No, you can get the crossover out from the woofer hole no prob. You just have to scrape it loose, takes a little patience and replacement requires some of that spray foam to resecure the XO.

Be careful replacing the woofs though, you can strip out the MDF real easy.

IT would be great if DM would tackle the 6.9 project. I would be willing to pony up some seed money as an incentive for this project. Too bad Hugh is selling these crossovers as a DIY because the design uses the same drivers as the 6.9 and might be a good starting point to re-engineer the 6.9 XO's.

http://www.printedelectronics.com/products/products_aksonics.html

mbarnes · « **Reply #25 on:** 4 Jan 2004, 06:50 am »

I have had several people want me to post my response. I did not read the posts here so I am only responding to the referenced web site.

I would first like to point out that almost all of the mini 9.0s and most of the 9.0s we sold were sold as kits. We sold the cases, crossovers, and wirng but our cusotmers installed the drivers. The fact that one of the drivers was wired out of phase could be the result of someone putting a kit together wrong. Most of the 9.0s we sold were upgrades that we sold at a very special price to people who bought the wood speakers.

Our crossovers were designed by Allen Issakson. He has a master's degree in accoustic design. He is the owner of DACT. He has designed several Vifa drivers. I believe he currently is responsible for QC for Vifa's plant in China. Allen used the LMS system to design the crossovers. We use the CLIO but we use it mostly for testing.

Both the Clio and the LMS system use what is called gating to get an accurate reading. The way gating works is that you measure the distance of the mic from the closest surface. This will give you the time for the first reflection. The system calibrates itself so that it produces a and measures a signal faster than the reflections can be measured.

If you measure a speaker without doing this proceedure, you are measuring the room as well as the speaker. Individually, you will get better results because you are tuning the speaker for the room.

I remember many posts a few years ago where people were reporting very accurate measurements using a calibrated sound meter. I think Tyson posted these.

We got many very good reviews on the 9.0s. TNT said it was the best two way book shelf speaker they had ever tested. The Malaysia Star said about the same thing.

I looked up the Liberty Audio Suite that was used in this test. I do not know much about this. It appears that it works with standard sound cards and that it is available as a free version and a version that costs money. I do not know which version was used in the test. I don't know what the differences are between the free version and the paid version.

Both Allen's LMS system and our systems has its own hardware. It has its own A/D converter and a calibrated mic.

The net is that I really do not know if the new crossover is an improvement or not. I sent this to Yuths and I would like to test the crossover myself. I personally own a pair of 9.0s and I am not opposed to improving them if this is indeed an improvement.

We can still get synthetic marble 9.0s but we can no longer get real marble 9.0s. As I predicted when we started this, the time would come when such speakers would not be able to be built again. Thailand's economy is now coming back. It is one of the fastest growing economies now in Asia. Our original suppliers are finding it hard to find, train and keep craftsman.

We currently have no problems with wood, synthetic marble or MDF. Ceramics are getting harder and harder to get. Our suppliers tell us that they can not get good yields without the cabinets cracking during the baking. This is because they have lost the craftsmen who did this work for us before.

As for the people who bought the 9.0s, you have something that might never be built again. Changing out a crossover or swapping a driver is child's play. Try to get another speaker carved out of stone and then you will see what we accomplished.

DeanSheen · « **Reply #26 on:** 4 Jan 2004, 06:57 am »

Thanks MB, much appreciated.

jackman · « **Reply #27 on:** 4 Jan 2004, 07:03 pm »

Assuming the problems with this speaker were caused by poor DIY assembly is a bit of a stretch, however, that fact can be easily determined by finding out when the owner purchased them. It does not explain, however why the mini 9.0 shares a crossover with the larger 9.0, even though they have different cabinets and different tweeters. I would expect more from a speaker that is touted as "world class" and that sells for several thousand dollars. It also doesn't explain the poor measurements on the 6.9's.

The true proof will be in the "pudding", when the newer crossovers are compared to the older version. I have heard the original version and have always thought the world class drivers and cabinets should have yeilded better sound dispite the positive reviews Michael sites.

Mr. Barnes also contends that the speakers may have been built from a kit and that may have accounted for the crossover problems. I would not consider this plausible rational because it was determined that the polarity on the tweeter was not the only problem with the crossovers. I believe the newer crossover is significantly different than the original one. The original crossover design seems to be the real culprit.

Again, the only thing that really matters is the sound. I look forward to hearing from nOrh owners who choose to try the newer design. Unfortunately, it may prevent me from scooping up some of the great deals on used 9.0's that I have seen! Before I'm accused of slamming nOrh or being antagonistic, let me make it clear that these speakers are amazing looking and use some of the best drivers on the planet along with the most solid enclosures. If the newer crossover sounds as good as some people say, these speakers are truly an amazing bargain.

Cheers!

J

ehider · « **Reply #28 on:** 5 Jan 2004, 08:01 am »

I want to applaud Mr. Barnes for answering this post and giving us some insight to how his crossover was developed.

I must say though that I personally think he should consider the fact that MANY well regarded high end speaker companies have produced excellent measuring speakers which were later determined to need some "tweaking" of their crossovers, even though the speakers measured perfectly!

One great example that comes to mind is Dunlavy speakers. They have to be one of the most "over measured" speakers ever produced. Dunlavy measured soooo many parameters that I think they may have had the tightest QC of any large scale high end speaker company. They used much better facilities and measuring tools than Mr. Barnes and most other small high end speaker companies too! Yet with all their measurements, I know quite a few audio industry insiders who purchased Dunlavys and then improved their crossovers! Some other examples of excellent well regarded speakers which have gone through many crossover "tweaks" (by their designers, not the actual customers) are Hales, Wilson, Avalon, Merlin, Pipedream, Thiel, Vandersteen, Von Schweikert and Talon. That's quite a few big nameswhich add up to over 300 years of combined design experience! Yet ALL OF THESE COMPANY'S DESIGNERS "tweaked" their crossovers through "lessons learned".

Here is my point in a nutshell

an absolutely great speaker is much more than calculations/measurements, great drivers and top flight parts!. (If it was that easy, then a companies like Sony or Pioneer could make great sounding high end speakers by purchasing Scan Speak drivers, do some calculations, verify the final product with calibrated mics then bring those speakers to market and crush the high end with low costs due to economy of scale purchasing/amnufacturing!) IMHO great speakers with true "inner soul" usually occur when the designer goes waaaaaaaay beyond the measurements!

I strongly feel that a competent high end speaker designer should ALWAYS try various crossover iterations that are beyond the "theoretical" perfect measured design. Calculations and verified response measurements are a very good start, but ONLY A START!

Based on what I know, most great speaker designers find the "true soul" of their designs byspending additional tweak time on their "perfect" measured implementations! It's a damn shame that most designers only do this on subsequent model designs, but I strongly suspect this is due to customer and/or dealer feedback, once their speaker is compared to other high quality competitors and small but noticeable issues are pointed out to the designer.

Hopefully, all of these discussions will motivate Mr. Barnes to compare other crossover circuit implementations (such as Murphy's) to his stock implementation. More importantly I hope he spends additional development time considering other circuit iterations of his crossover and understand how he can find additional soul in his speaker offerings.

WerTicus · « **Reply #29 on:** 5 Jan 2004, 10:42 am »

i can pick another fault with the new x over design...

its still a passive xover!

why not bi amp the thing its only at two way

Jay S · « **Reply #30 on:** 6 Jan 2004, 01:07 pm »

Michael,

I am glad you took a look at Dennis Murphy's site. Please do try out his XO design and let us know what you think.

For those of you interested, www.soniccraft.com sells very high quality XO parts. Jeff Glowacki can build an XO. Btw, I costed out the cost of the parts for Dennis Murphy's design using Soniccap XOs, Mills resistors and Alpha Core inductors... comes out to about $81.90 (using the nearest available value if exact ones not available).

Jay S · « **Reply #31 on:** 6 Feb 2004, 01:12 am »

Hi all,

Has anyone had a chance to try the new XO design? I'd love to hear your thoughts on how it compares to the stock XO. I imagine that the difference will not be subtle.

Cheers,

- Jay

jackman · « **Reply #32 on:** 6 Feb 2004, 01:50 am »

Dennis was offering a "test" crossover that he had put together for people who wanted to see if they liked the new crossover. I think you only have to pay shipping to and from Maryland. If I had a pair of 9.0's, I'd jump at this offer. Plus, I imagine seeing the crossover configuration will be a real bonus to people who are trying to put together their own.

Dennis recently designed some new crossovers for a pair of ribbon monitors I have and they sound amazing. Although he doesn't do this for a living (or take any money for his designs), he is a musician (violinist) and has a good ear for great sound, and, fortunately, the ability to design great sounding speakers. You should give him a call and get on the trial list for the upgraded 9.0 crossovers. Hopefully, nOrh will give them a listen. I'd be shocked if they weren't a large step up from the existing xovers.

Jack

Xi-Trum · « **Reply #33 on:** 8 Feb 2004, 02:46 am »

How and where can I contact Dennis? Thanx.

jackman · « **Reply #34 on:** 8 Feb 2004, 03:14 am »

Hi Xi,

Go to Murphyblaster.com. Dennis is a really cool guy who does this for the love of audio. He's a no-nonsense guy who is very modest and really helpful. I look forward to your impressions of the new crossovers.

Jack

Audi-O · « **Reply #35 on:** 8 Feb 2004, 04:44 am »

Hey Jack, how ya been? It appears you like Dennis's work.

I still have yet to hear your little ribbon monitors. Did you get the others built?

Did Dennis design the x-overs in your 1801s?

jackman · « **Reply #36 on:** 8 Feb 2004, 04:49 am »

Hi Ron,

Yes, Dennis did the Xovers in the 1801's. The ribbon monitors sound very good. There is a lack of vertical dispersion because the tweets are ribbons. You can get around this by having several ribbons in a line array, plus some smaller ribbons like the Arum Cantus seem to have better vertical dispersion than the larger Silver Flutes, however these tweeters sound very good and the speakers overall sound very good. I have them both and will bring them to your place soon. My CD player is at the Doctor getting a checkup, but you have to hear it when it returns.

I hope to get together soon. Have lots of new music that I'd love to hear on that beautiful Naim system of yours.

Jack

hrbngr · « **Reply #37 on:** 16 Feb 2004, 04:01 pm »

hello,

just wanted to post that it was my marble 9s and mini9s that Dennis tested. I would have already installed a set of crossovers, but in the process of testing, two of the metal backplate rings became "unglued" from the speakers. i am still trying to get some epoxy to fix the problem. I then hope to put the new crossovers in--especially in the Marble9s.

I can say that the speakers sounded quite a bit better w/the re-designed crossover, however, i am not enough of an expert to tell you how it sounded better except for noting that the new crossover seemed to improve the vocals and midrange in clarity, and also widened the soundstage.

i really need to get those speakers fixed so i can listen to Marble 9.1s!!!

Jay S · « **Reply #38 on:** 16 Feb 2004, 04:38 pm »

Thanks for the post/update. This is an exciting project and hope you can get your speakers up and running again soon! Do keep us in the loop.

hrbngr · « **Reply #39 on:** 19 Feb 2004, 01:14 am »

Jay S,

I will keep you updated. I do have two pairs of Marble 9s so I will be able to A/B compare them. Thanks for the info on soniccraft.com. I spoke w/Jeff and will order the parts from him later this week.

I still need to address the epoxy issue for the mounting rings, but i hope to do so this week as well.