Is nonlinear distortion of (small) speakers unimportant??

[Doodski]

You'd be flat out "upselling" off a NS-700X or NS-1000X. If someone was looking at some JBLs down the road, you could ruin them forever with a demo of the NS-1000X.

I dunno about that but the JBL Ti series was pretty loud, proud and bright like the NS-X stuff. We never carried anything more than the NS-700X and it was there mostly to appease Yamaha because we had a territory. Peeps had very good success with the Yamaha large and small monitor speakers but I was more of a KEF, Mission and B&W guy because we had territory on those too and they sounded better as in not as Japanesey sounding brash and midrangey.

 

[direstraitsfan98]

I dunno about that but the JBL Ti series was pretty loud, proud and bright like the NS-X stuff. We never carried anything more than the NS-700X and it was there mostly to appease Yamaha because we had a territory. Peeps had very good success with the Yamaha large and small monitor speakers but I was more of a KEF, Mission and B&W guy because we had territory on those too and they sounded better as in not as Japanesey sounding brash and midrangey.

Love those 250Ti's! Very large, very heavy speaker.

 

[Doodski]

Love those 250Ti's! Very large, very heavy speaker.

DittO! I would love a pair of 250Ti. Amazing mid range, great highs and bottom end to die for. We carried them in the day and we where very sorry to see them go at the end. The customers loved them.

 

[andreasmaaan]

Sealed. Acoustic suspension, infinite baffle relatively interchangeable terms.

Funny, I'd never heard "infinite baffle" used in this way before.

 

[restorer-john]

I would love a pair of 250Ti.

Me too.

More expensive than the NS-1000X, I don't remember what they sold for. Here's a May 1984 price list with the L-250 (non Ti).

Oh, and the 6.5" two way toy JBL, the L15 was, wait for it, the entry level speaker in the L series:

And for your enjoyment, the monitor price list...

 

[Doodski]

Me too.

More expensive than the NS-1000X, I don't remember what they sold for. Here's a May 1984 price list with the L-250 (non Ti).

Oh, and the 6.5" two way toy JBL, the L15 was, wait for it, the entry level speaker in the L series:
View attachment 51596
And for your enjoyment, the monitor price list...
View attachment 51597

The entire JBL Ti line at the time was great. I didn't appreciate it and support it as much then as I do now. Efficient, durable, decent finish and great warranty and those pro monitor models where L O U D !

 

[Blumlein 88]

I remember serious hifi guys in the 1960's and to them infinite baffle was mounting drivers in a wall or door with a large closet or entire room on the other side. It wasn't about pressurizing the enclosed space or using it as a compliant air spring. It was in effect a dipole arrangement where the baffle had dimensions that exceeded the lowest response of the driver. Same idea with woofers that vented the back into a large basement. It was intended to operate like a giant dipole baffle.

The tuning and drivers needed were nothing like acoustic suspension designs.

 

[Doodski]

I remember serious hifi guys in the 1960's and to them infinite baffle was mounting drivers in a wall or door with a large closet or entire room on the other side. It wasn't about pressurizing the enclosed space or using it as a compliant air spring. It was in effect a dipole arrangement where the baffle had dimensions that exceeded the lowest response of the driver. Same idea with woofers that vented the back into a large basement. It was intended to operate like a giant dipole baffle.

The tuning and drivers needed were nothing like acoustic suspension designs.

Heck for that matter turn the chimney into a long tuned port fed back into the house >@^_*@<

 

[Blumlein 88]

@RayDunzl has done some real IMD measurements with his speakers.
https://www.audiosciencereview.com/forum/index.php?threads/how-audible-is-distortion.2047/post-55827

One could use Pkane's Distort to create a profile that mimicked speaker distortion profiles by measuring a few static THD and IMD points at different sound levels on your personal speakers. Then test at a more comfortable level how much speaker IMD becomes audible with music. Then go back and see if your real speakers distort audibly or not.

 

[Blumlein 88]

Heck for that matter turn the chimney into a long tuned port fed back into the house >@^_*@<

My mother's best friend had a father in law with just that arrangement. Old house with a fireplace they no longer used. He put a pair of 12 inchers on a double layer plywood baffle covering the old fireplace and let the woofers fire out the back up the chimney. The top of the chimney was covered by coated canvas to weatherproof the back side. The idea being it wouldn't impede sound. Not sure how true that was.

I don't have strong recollections of it other than it had lots of muddy low end. He was more of a HAM and dabbled a little into audio always in mono.

Modern version of the same idea.
https://www.hometheatershack.com/threads/fireplace-ib-build.136818/

Old forum dedicated to the idea. Hear the woofer not the box. Infinite baffled subs.
https://ibsubwoofers.proboards.com/


http://www.cowanaudio.com/ib.html
Seems like this would leak noise from his AC unit into the house.

 

[Doodski]

My mother's best friend had a father in law with just that arrangement. Old house with a fireplace they no longer used. He put a pair of 12 inchers on a double layer plywood baffle covering the old fireplace and let the woofers fire out the back up the chimney. The top of the chimney was covered by coated canvas to weatherproof the back side. The idea being it wouldn't impede sound. Not sure how true that was.

I don't have strong recollections of it other than it had lots of muddy low end. He was more of a HAM and dabbled a little into audio always in mono.

I saw the idea in some old 1950's mechanics or science magazine decades ago. The premise has potential. I suspect lots of power and large woofers would be req'd.

 

[Blumlein 88]

More IMD measures by Ray.
https://www.audiosciencereview.com/...ds/distortion-in-loudspeakers.1297/post-33698
Both on his LSR 308s and ML electrostats.

 

[restorer-john]

My understanding is a bit different to that, FWIW.
Infinite baffle, at least historically, meant isolating the back wave by an essentially infinite physical barrier -- e.g., a wall. The next best thing is a very large sealed box.

I stand corrected.

It appears Yamaha Australia used the term infinite baffle for a sealed cabinet when Yamaha Japan itself (I just looked at the full range of individual brochures for each model) use either acoustic suspension for sealed, or bass reflex for a tuned/ported cabinet.

I wonder at what point does a speaker transition from a large acoustic suspension design to an infinite baffle where significant efforts to prevent reflections from the back of the cone are taken (massively packed damping, large cabinets etc)? As both an acoustic suspension and an infinite baffle both have a volume of trapped air behind the cone...

 

[Hiten]

Sorry for offtopic.
I have seen measurements of vintage amplifier here. Of good quality they pretty much hold on to specifications. Except some power supply noise. But regarding speakers; do quality speakers from yesteryears keep same performance quality ?
Regards

 

[restorer-john]

To be honest, the reviews on ASR somewhat of a joke. The way Amir treats his measurements as gospel, his hostile towards valid criticisms of his tests, his dismissal of said valid critisims, and the sensationalist nature of a lot of his conclusions when it comes to products. Myself, I see it as not very genuine. I think I'm in the minority here in thinking this though.

Whatever. There's still a lot of good to be had from here, and being here, so I usually set all of that aside. It's easy to turn a blind eye from it. And even if I wanted to voice my lone voice of dissent, it would just get drowned out by 500 parrots all screeching the same thing.

As long as the technical reviews are interactive, with any and all members being able to comment, it won't change.

You've got one man making the measurements and depending on whether the device tests well or poorly, comments and the thread direction go from worshiping the product to a complete and utter pile-on demolition of a brand. It's funny to watch sometimes.

If the technical reviews were presented as professionally written, objective, locked thread reports and a separate discussion thread on the review was fully interactive, the reviews could stand alone without being filled up with garbage. If the review has errors or measurement mistakes, they are corrected and duly noted in the review thread itself. The discussion threads can go off on whatever tangent they want and arguments can happen there. It would be a cleaner user-experience IMO. Eventually, the discussion threads will run out of steam and become dormant, but the review threads will still stand, hopefully with quality reports, and minor updates, notes or errata, and be a useful reference.

I can see Amir needs to defend his methods and measurements, even in the face of criticism, be it valid or not. It's also not remotely a sign of weakness to admit you are wrong sometimes. But he also can see his genuine hard work get watered down by hijacked threads and petty infighting. Must get frustrating.

That said, I agree with much of your post and thanks for having the guts to post it.

 

[Doodski]

Sorry for offtopic.
I have seen measurements of vintage amplifier here. Of good quality they pretty much hold on to specifications. Except some power supply noise. But regarding speakers; do quality speakers from yesteryears keep same performance quality ?
Regards

Pretty much yes. I like the various older KEF Reference series, have owned a large set and after 20 years or more they still sounded fantastic.

 

[restorer-john]

do quality speakers from yesteryears keep same performance quality ?

Some do, some don't. Not a universal yes or no unfortunately. I've had wonderful speakers where the butyl/rubber surrounds have changed their characteristics, spiders that have hardened up and doped fabric surrounds that have gone so hard on midranges that the speakers were a write off. We've all seen collapsed suspensions on large vertically mounted drivers and even tweeters can suffer changes to their performance as ferrofluid dries out/goes sticky etc.

Voice coils can and do de-laminate and in moist (humid) areas, cabinets can change their sound, especially biscuit board and MDF ported cabinets.

Much as I love a lot of vintage gear, I wouldn't be spending big dollars on speakers from "yesteryear". If they are cheap, by all means, but paying top dollar for a pair of Yamaha NS-1000Ms (for example) is a silly idea.

 

[pma]

Focal was making very nice speaker drivers

https://site.diy-loudspeakers.com/d...tasheets/161-very-old-focal-driver-datasheets
https://site.diy-loudspeakers.com/i...ry_old_focal_drivers/FOCAL_MIDRANGE_7V313.pdf

They started to disappear about 15 - 20 years ago ...

JM Lab Utopia, Wilson Audio Maxx - my favorite big speakers.

 

[restorer-john]

Focal was making very nice speaker drivers

What happened to Focal? Did they get bought out? I saw some newish low-mid range models at a local store a while back and got excited, until I looked hard at them- they were really cheaply made.

 

[Doodski]

Some do, some don't. Not a universal yes or no unfortunately. I've had wonderful speakers where the butyl/rubber surrounds have changed their characteristics, spiders that have hardened up and doped fabric surrounds that have gone so hard on midranges that the speakers were a write off. We've all seen collapsed suspensions on large vertically mounted drivers and even tweeters can suffer changes to their performance as ferrofluid dries out/goes sticky etc.

Voice coils can and do de-laminate and in moist (humid) areas, cabinets can change their sound, especially biscuit board and MDF ported cabinets.

Much as I love a lot of vintage gear, I wouldn't be spending big dollars on speakers from "yesteryear". If they are cheap, by all means, but paying top dollar for a pair of Yamaha NS-1000Ms (for example) is a silly idea.

In your experience how long does ferro fluid generally last before it degrades?