Hum & Buzz in AV Systems

[rickcr42]

www.jensen-transformers.com/an/generic%20seminar.pdf

www.jensen-transformers.com/an/ts_guide.pdf

www.jensen-transformers.com/an/an004.pdf

www.edn.com/archives/1998/060498/12df_03.htm

[Deleted]

Rick
You don't have shares in a steel company do you ?
You singlehandedly seem to be trying to turn back th clock to the general use of trnsformers in audio.. Like Allan, I am more than aware of the unbalance in transformers used in audio. In Telecommuninications 100s of thousands of them were used in Cailho circuits etc.They were finicky in use, and often caused unstable carrier channels etc, causing "hollow sounding " speech. Good riddance to them , I say ! Except of course in very specialised circumstances. A good MC stepup transformer, however, could be one of them.

SandyK

[rickcr42]

if you onlyknew your "turn back the clock" only applies to those who have no idea what TRUE high end audio systems are suing and just how far audio iron has come.

Op-amps as "synthetic" inductors,balanced amplifier chips as "synthetic" balanced transformers,solid state "synthetic" gyrators replacing tone controls,SS Current Mode "synthetic" step up transformers :

ALL to save build cost/product cost and NOT about improved performance if you actually read the available literature and even between the lines of some of the more honest shillers.Never was about what is the best way but what does it cost and how hard is it to optimise and why we get DAC chips with "everything inside the box" becvause even they realised most so called audio engineers had no idea and were mucking things up when left to their own deivces to get the analog section right. ;D

Plus I never heard yet of a transformer going belly up when hit with a mains transient untlike FAR too many products I have owned because the bipolar transistor is a damn delicate piece of work that if compared to the IRON alternative would be the blushing girl to its full grown man

If there is a limitation it is at the bottom end and even that is a plus since most systems can dearly use a low end cutoff point even IF the user has no idea he does and anyone with a true sub will tell you how much clearer everything sounds once they got a proper low cut in system to get rid of the grunge doing no more than wasting power and causing woofer flap so even that cat won't chase the mice down

[Deleted]

If there is a limitation it is at the bottom end and even that is a plus since most systems can dearly use a low end cutoff point even IF the user has no idea he does and anyone with a true sub will tell you how much clearer everything sounds once they got a proper low cut in system to get rid of the grunge doing no more than wasting power and causing woofer flap so even that cat won't chase the mice down

Rick
I presume you are referring to Vinyl based systems ? If so, I agree. If you are using a valve amplifier with output transformer, part of those requirements is already taken care of by the low frequency rolloff of the transformer.
If not, I vehemently disagree ! Are you able to play decent,and recent, high resolution material, such as the Linn downloadable material,with artists such as Claire Martin ? (24/96 or higher)
In material like that, an extended bottom end in the amplification is a definite plus.
As for subwoofers ? YUK ! There are many speakers available these days that go down as far as (or further) than your average subwoofer, and do the job better, without the added audible degradation associated with filter use, and another added stage of amplification. Even Miguel has DCM speakers with a very good low end extension. My speakers come from the same family of speakers.

Plus I never heard yet of a transformer going belly up when hit with a mains transient untlike FAR too many products I have owned because the bipolar transistor is a damn delicate piece of work that if compared to the IRON alternative would be the blushing girl to its full grown man

Isn't that what mains suppressor power boards are designed to prevent ? Recently , I moved house, and hadn't got around to finding my home brew suppressor board and putting it in line.
Little did I know about the new substation they were building further up the street for the new Hornsby shopping centre. Well they "hit" something, and it took out the transformer primary windings in 2 transformers in my Class A PSU box ! The power output devices, in fact, ALL the electronics survived, mainly due to PSU regulation.

SandyK

P.S. I think both our biases are showing ?

[rickcr42]

Rick
I presume you are referring to Vinyl based systems ?

Nope.AUDIO systems in general.There is more power wasted and more system based error caused by power robbing at the "below audible" low end that I fail to see why anyone would want to see "dead flat to 2hz" as if they can actually get that with ANY headphones or with ANY speakers in a real world real room without wrecking the joint IF they had a few thousand watts of power hanging around.

There is a DIY Subwoofer article by JBL on the web that i will dig up that explains in real terms what is involved in powering for REAL bass and what having a low cut means in reality instead of some idea of perfection no one can reach except in the lab on a scope screen.As soon as I remeber where it is I will post it

[Deleted]

Rick
I have read much of that stuff too. But it is just viewpoints from commercial interests designed to help sell their products. There is also plenty of material with opposing views, but not so prominent, because of advertising budgets of big audio companies. ;D
IMHO, with Audio, as in many other fields, there are many different ways "to skin a cat" and end up with a similar result.

BTW, I think you may have replied before I finished fiddling with the previous .
Alex

[rickcr42]

the plans from Audio Magazine :

www.lansingheritage.org/html/jbl/reference/technical/1983-subs.htm

The commercial versions of the subs

www.lansingheritage.org/html/jbl/specs/home-speakers/1983-b380-b460.htm

www.lansingheritage.org/html/jbl/specs/home-speakers/1982-l250-b460.htm

the precursor to the JBL article is one I had (maybe still have) from an earlier "Audio" article with the background and it WAS once online but has been gone for years as far as i can tell (author,I think,is hodges) has more on the subject.In fact i actually built that sucker back then and had it for years but had to give it up the sub being the size of a LARGE refridgerator and heavy as hell to move

[Deleted]

BTW, There are very few things that are more antisocial than subwoofers that artificially augment the low end. Both in cars of soon to be deaf people, that rattle the metal panels of other passing cars, and can be heard coming from > 1/2 a mile away (further at night !)
OR, neighbours with subs that go "boom,boom,boom", without anything else being audible, in adjoining houses, and across the street's houses, even with all the windows and doors shut in the adjoining houses ! Thank God for noise abatement regulations that are slowly being introduced !

SandyK

[rickcr42]

the best bass I have personally ever heard was a transmission line loaded sub and from a horn loaded enclosure but the "throw" meant you could sit right next to it and not hear it yet back up ten feet and it kicked you in the chest then in the corners sounded entirely different again-one of those weird things sound contractors know about but that we muddle through and why so many systems sound like shit even though high dollar value.Matching not just the amp to the speaker but the croissover point,the low end cutoff point,the phasing (not the absolute phase but the "tweener" phase ),room size in relation to the cone and F3 and amp power and shape and.......

You can FORCE bass on a room, even a piss poor cube shaped one,but takes a damn lot of work to get it to sound like part of a "system" rather than a thud and boom box that is more special effect than filling in any missing octaves or making those present more tactile

[XTRProf]

Great projections and counters there. But I'm find it rather amusing to have so much bass power that could literally disturb your neighbours that can results with law suits coming as well as police coming. Of course, if u have an anechoic house like those testing ballistics ammo indoors as in the arms companies, this will not apply. Do u guys feel happy about those boom boxes passing ur place at night r even day?

Yes, I had experienced the ultimate bass seeing Earthquake the movie in subsonic surround that rocks everything including urself when I was taken by my parents to see it many stars back. My god, my little brother down south will fly away if not attached and will sue my as well if possible.

[Deleted]

You can FORCE bass on a room, even a piss poor cube shaped one,but takes a damn lot of work to get it to sound like part of a "system" rather than a thud and boom box that is more special effect than filling in any missing octaves or making those present more tactile

How about we leave this quote as the closing post in this thread ?
I couldn't agree more ! ;D
SandyK

[rickcr42]

And give you the last word ?

not on my watch bubba