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How to dissect polar patterns and frequency responses for horns.


Droogne

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On 3/2/2018 at 12:52 AM, muel said:

 

Rather off the OP's topic but I tried 4 of their (Universal Music Japan) SHM-CD's and was pretty UNimpressed with their dynamic range... actually on the lower end of the spectrum compared to other versions on the DR database.   Now what I bought weren't exactly typical audiophile albums but some rock CD's that I either didn't have and were on my "buy some day" list or I wanted a better version.  Expensive fail for me.  You might say I don't have a "yen" for anymore.  

 

The "SHM" is just some marketing thing that was invented by the Japanese. You specifically want the Platinum series, otherwise the number of regular SHM releases are probably over 1000 and the mastering on these type of discs is more often compressed with the treble boosted. These are just regular reissues with the "super high material" designation applied to them.

 

The very short lived Platinum series were genuinely flat transfers from either US or UK master tapes and verified by the engineers that people have contacted them about (it is also written in the booklets). These were basically created as archives of master tapes (some other labels are digitizing their analog master tapes like Blue Note and Decca) that the Japanese released on CD and SACD.

 

Sorry didn't see this or your message earlier, my practice has been incredibly busy this year and I haven't had much time for message boards.

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  • 2 months later...

@Chris A

 

Hey

 

Seen a lot of good reviews about the JBL M2 studio monitors, and primarily about their horn. It seems they also boast an extremely good polar control. Have you had the chance to hear them maybe? Or have theoretical comparisons between them? 

 

Thanks

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I've not heard a pair of M2s yet so I can't be of much help on that subject.  I'm sure that they sound superb from 500 Hz up.  But I still wonder why JBL continues to use ported (direct radiating woofer) cabinets on their high end loudspeaker models, and most especially, failing to talk equally about that portion of the spectrum with its non-uniform polars vs. frequency.  I've found that having good polar control below 500 Hz has a disproportionate effect on the sound of the loudspeaker in-room, as well as the cleanness of vocal and speech recognition.  It's as if they are saying, "well, that part is too hard, so we'll just avoid that subject". 

 

It isn't too hard, BTW.  But it is as if JBL continues to push ported woofers, so no one will ask questions.  Danley provides a different solution with their larger Synergy series loudspeakers (multiple entry horns), and so does Klipsch with the Jubilee and their larger behind-the-screen cinema systems based on MWM bins. 

 

It seems to me that multiple entry horn (MEH) designs are tailor made for home hi-fi duty. 

 

Chris

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Well I was thinking the exact same thing. I must say I'm basing a lot on things you told me, but I have been looking a lot at the behind-the-screen models of their cinema line, as well as to the M2, and I did wonder how this direct-radiating model could ever be so superior.. Everyone is raving about it, and I believe that they sound amazing, but why would they leave out the horn loaded bass? It seems like theyre going all out on everything, but neglecting the bass. It is a fact though that the M2 is a studio monitor, and that that could explain the direct firing model no? This way they boast a flat response from 20-20000hz which is something that comes in pretty handy in mastering etc?

 

That aside. It looks like the best part about the M2 can be bought seperately! (https://reconingspeakers.com/product/jbl-m2-horn-lens-5025594/) . This is without a driver, and is not unreasonably priced, which made me curious. Not convinced. But curious. Still want to go 100% for the MEH. 

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Also you're definitely not the only one frustrated by the direct radiating in the M2: "

 

I was quite impressed with the wide dispersion, clarity and neutrality of these speakers when I heard them at an AES Convention a few years ago. Only wished they were not vented. The horn compression driver is an ingenious dual diaphragm design by Alex Voishvillo for extended high frequency coverage and low distortion at high output levels.

Alex Voishvillo, Dual Diaphragm Compression Drivers, AES Convention Paper #8502, NY 2011"

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  • 2 weeks later...

Just a couple of comments. 

They probably skipped the horn loaded bass for a couple of reasons. In order to get low-frequency extension, the cabinets would need to be huge and even then they might still require corner placement. Needless to say the production costs go way up when constructing a horn loaded bass bin. They do achieve low frequency extension by porting the cabinets and the woofer is expensive (techniques were used to limit any compression when driven hard). Each woofer alone costs $600. This is about 4 times the cost of the K-31 or K-33. 

 

For those wanting to purchase the upper horn: good luck. The vendors may list them but not sell them to DIYers. 

 

Personally, I think that the K-510 horn is still a good choice if you are contemplating a two way system with a vented bass bin (and need a tweeter horn of reasonable size). This is especially true if you can cross over to the tweeter above 500Hz or so. The JBL M2 crosses at 800Hz

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The woofer does seems really high quality, thats true. I also thought it was about the frequency extension and size. Does make sense :) As far as I know the retailer I linked, and contacted, did sell them. Doesnt really matter as it doesnt like I'm gonna buy them. I'm happy with the K510 on my LaScalas for now!

 

 

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