Something stirs in the Undergrowth

Dedicated to those large boxes at one end of the room
User avatar
IslandPink
Amstrad Tower of Power
Posts: 10041
Joined: Tue May 29, 2007 7:01 pm
Location: Denbigh, N.Wales

#886

Post by IslandPink »

Signal generator fixed :bounce:
"Once you find out ... the Circumstances ; then you can go out"
User avatar
slowmotion
Old Hand
Posts: 282
Joined: Fri Aug 21, 2009 4:07 pm
Location: Norway

#887

Post by slowmotion »

Mark, question for you , what is you mean decibel level while listening?
- Jan -
User avatar
IslandPink
Amstrad Tower of Power
Posts: 10041
Joined: Tue May 29, 2007 7:01 pm
Location: Denbigh, N.Wales

#888

Post by IslandPink »

Not measured lately, but I did a while back - I reckon 90dB Max, typically more like 70-80 . Next time I can remember, I'll check again .
"Once you find out ... the Circumstances ; then you can go out"
User avatar
slowmotion
Old Hand
Posts: 282
Joined: Fri Aug 21, 2009 4:07 pm
Location: Norway

#889

Post by slowmotion »

I'm just curious, is all.
I'm at about 80dB.

Trying to figure stuff out...
- Jan -
phivates
New User
Posts: 4
Joined: Sat Dec 21, 2013 5:47 am

#890

Post by phivates »

Sorry I fed the troll. And thanks for the links Lynn.
Romy The Cat
User
Posts: 86
Joined: Tue Jan 28, 2014 10:23 pm
Location: Boston, MA
Contact:

#891

Post by Romy The Cat »

What is unfortunately characteristic that this site, like any other audio sites, populated with two categories of people. First group are the people who know what they want, have sense of identity about themselves, about what they are looking and they are interested is some interaction about the methods to accomplish what they need. They are just a few people at this community and their presence is very distinctive. The rest of the people is a typical audio dirt - the industry losers who never succeed in anything worthy and now they are desperate to fake own eulogy, the lost in life mid-age teenagers who run from site to site and from hand to hand trying to render endless purposeless projects, the assholes overwhelmed with sense of self-importance and because their kids belie that they are idiots they go online and insist to be pedagogical, the absentminded bystanders who are desperate a rise scream about any reasons as they are bored in life and internet is the only entertainment they have. There is nothing new.... I am a nice guy and to the whole second group I do wish what Chris The Salieri suggested in the wonderful movie "Ritzâ€￾: to die with your pathetic little secret. As far as I concern you are already dead to me, always were....
Lynn Olson
User
Posts: 141
Joined: Tue Dec 17, 2013 3:48 am
Location: Northern Colorado, USA

#892

Post by Lynn Olson »

IslandPink wrote:Tone Tubby is so far proving to be promising, but difficult to run-in.

It still sounds closed-in and lacking in mid tone compared to the Jensen P12N that was on the test baffle before - but I've read several reports on the guitar forums that the TT hemp cones & surrounds need a lot (eg. 50hrs) of heavy-duty running-in at 20-30W to get them sounding right.
Glad to hear the signal generator is back on-line. An alternate method is placing the two cones face-to-face, connect the two in series, but with one of them out of phase, and powering with a single 6.3V filament transformer. 6.3Vrms into 16 ohms is 2.5 watts, pretty loud, but connecting the cones out of phase cancels most of the sound while leaving the cones free to move.

I'm a bit concerned about the long run-in time. The two Red TT's I heard on small, flat OB's sounded good right out of the box. There was all the weird TT arcana about non-dipped, single-dipped, and double-dipped cones, and I'm guessing that I heard the most popular single-dipped version, but I'm not sure about that. The dipping process apparently stiffens the center of the cone, which creates a bigger peak in the midrange, which guitarists like.

The Red versions I heard were anything but closed-in sounding. The "blat" on a trumpet solo damn near knocked me out of my chair. It sounded like the trumpet player was only a few feet away, and you know how loud a live trumpet can sound. No pretense of a flat response, but a very different colouration than a Lowther, and missing the whizzer-cone roughness in the 2~5 kHz region.

Tone Tubby tells us very little about the hemp cones that give their speakers their distinctive tone. You'd think with hemp, and stronger, now legal here in Colorado, TT would be a little more forthcoming. Maybe they should move here and use the all-local product.

Side note: News on TV tells us that Colorado expects to clear $180 million in taxes alone on pot sales this year, based on sales since the beginning of the year. There are lots of local jokes about "stoners on the slopes", but in reality, that's how it's been for a long time for the ski and snowboarder crowd.

My nutty right-wing friends told me at the RMAF show that Colorado was becoming a "socialist hellhole" like California (they get their news from Glenn Beck websites), and I laughed in their face. Coloradans love to make money. It's a state founded by Gold Rush miners, and still feels that way. There's more small businesses here than I've seen anywhere outside of Hong Kong.
User avatar
IslandPink
Amstrad Tower of Power
Posts: 10041
Joined: Tue May 29, 2007 7:01 pm
Location: Denbigh, N.Wales

#893

Post by IslandPink »

Yeh, it's a bit frustrating , as James and I discussed the pros and cons of the Reds vs. the 60W 'Blacks' and 16 ohm vs. 8 ohm for a while before settling on the 8 ohm Blacks. There was a small advantage in terms of low-end response and flatness. I remember your comments about the trumpet sound, plus the very positive comments on the Lowther America site. Interesting you say the good results came 'out of the box' .
The Blacks are 'double-dipped' , by the way , but have slightly less of a midrange peak than the reds , at least on the measured plots.
Maybe if things don't work out I can do a deal with Denis Cornell to get a pair of Reds in exchange, for some reasonable 'consideration'.

As I write , one driver still rumbling away upstairs at 25Hz and about 8W :D
"Once you find out ... the Circumstances ; then you can go out"
User avatar
Paul Barker
Social Sevices have been notified
Posts: 8875
Joined: Mon May 21, 2007 9:42 pm

#894

Post by Paul Barker »

Lynn Olson wrote:An alternate method is placing the two cones face-to-face, connect the two in series, but with one of them out of phase, and powering with a single 6.3V filament transformer. 6.3Vrms into 16 ohms is 2.5 watts, pretty loud, but connecting the cones out of phase cancels most of the sound while leaving the cones free to move..
That's a very useful tip.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
phivates
New User
Posts: 4
Joined: Sat Dec 21, 2013 5:47 am

#895

Post by phivates »

There's a third category: troll
steve s
Shed dweller
Posts: 2829
Joined: Wed May 30, 2007 6:19 pm
Location: east yorks

#896

Post by steve s »

Lynn Olson wrote:An alternate method is placing the two cones face-to-face, connect the two in series, but with one of them out of phase, and powering with a single 6.3V filament transformer. 6.3Vrms into 16 ohms is 2.5 watts, pretty loud, but connecting the cones out of phase cancels most of the sound while leaving the cones free to move..
But but but.. Surely running in speakers is about getting them to break up, they need an air load, not cancellation

Running in lowthers a few years ago, the long back horns i used at the time give the driver a load,and they were soon sounding smooth..(well for lowthers) whereas running them in on open baffles later on was a long drawn out affair. My view is that speakers need to be run in at all frequencies to ensue they end up with smooth beakup accross the cone
The tube manual is quite like a telephone book. The number of it perfect. It is useful to make it possible to speak with a girl. But we can't see her beautiful face from the telephone number
User avatar
IslandPink
Amstrad Tower of Power
Posts: 10041
Joined: Tue May 29, 2007 7:01 pm
Location: Denbigh, N.Wales

#897

Post by IslandPink »

I take your point, Steve, though I had been thinking the mixed-frequency effects would happen with music , as I've been playing a fair bit in between the deliberate run-in upstairs.
Maybe I'll grit my teeth and try a few higher frequencies with the signal generator - though not at 8W !
"Once you find out ... the Circumstances ; then you can go out"
Lynn Olson
User
Posts: 141
Joined: Tue Dec 17, 2013 3:48 am
Location: Northern Colorado, USA

#898

Post by Lynn Olson »

I guess it depends if you want to soften the surround + spider or the whole cone assembly. The 50/60 Hz business is plenty good enough for the surround + spider.

Since direct-radiator drivers are constant-acceleration devices, excursion increases at a rate of 12 dB/octave as frequency decreases. To move the surround + spider as far as possible, lower frequencies are desirable; higher frequencies create acceleration more than displacement.

But some break-in processes might involve acceleration stresses re-shaping the fibers in the cone (and glues). This is where white or pink noise are useful, since they are broadband and stimulate all frequencies. (White noise has equal energy per Hz, and sounds tipped-up, while pink noise has equal energy per octave, and sounds flat.)

Since analog pink and white noise sources are a nuisance to track down, you can use a computer with a pink or white noise track and cycle it over and over again. That's what I used on the new Audio-GD SA-2 for the month of January. The thing sounded great for the first hour, and promptly went downhill after that, so I engaged the white-noise track on the computer, and left it going 24/7. After 200 hours, the sparkle and immediacy returned, and after 600 hours, it was sounding really, really good, with the the vivid tone colors fo the Burr-Brown/TI PCM-1704 fully in evidence. It just took a very, very long time.

One of the less welcome aspects of complex analog transistor electronics can be an extremely long break-in time ... while tube electronics come "on song" in a matter of minutes or hours. I'm pretty sure it's all the dielectrics that are changing over time, and circuit boards are notoriously low-quality dielectric (compared to Teflon or polypropylene). Transistor circuits also use lots and lots of electrolytic capacitors as bypasses in power supplies and local device decoupling.

There's not much dielectric in a loudspeaker, just the interwinding capacitance of the voice coil windings, and the layers of insulating varnish that separate them. A few picofarads at most, and the effect of a few pF at speaker impedances is going to be very small.

I'm kind of dubious about the wire itself needing any running-in. It takes real power to re-anneal copper, even at the crystal-grain level. A few watts ain't gonna do it.

To the extent the Tone Tubby is needing running-in, it's most probably at the mechanical level, not dielectric or re-structuring the grains in the copper wiring. LF drive will reform the surround + spider, and HF drive (preferably broadband) will alter the cone (and glues) through acceleration.

IslandPink, I feel some culpability in starting this whole Tone Tubby thing. Thom Mackris was considering picking up the Bastanis product line, and I mentioned to him the entry-level model he had sounded very different than the high-end model we both heard at the RMAF show. It turns out the entry-level model uses a generic Eminence driver, while the fancy one uses a modified guitar speaker, purportedly of East European origin and with lots of time-consuming cone treatments.

I wasn't sure if I bought the whole "made in the Black Forest by elves" sales pitch, but I was pretty sure you could do better than a generic Eminence driver. Thom plays electric guitar and suggested the new wonder-cone Tone Tubby. A couple FedEx days later, two of the red wonders arrived (and boy, are they glossy red), and Thom replaced the drivers in the entry-level Bastanis. (All thought of actually selling Bastanis had long fled our winter-crazed minds.)

By golly, the red Tone Tubbies sounded good! Way better than the cheapo Eminence (but that isn't saying much). But it has to be kept in mind that Bastanis uses these 12" drivers as midranges, not bass drivers. There's a closed-box bass module that comes in around 220~240 Hz or so, and a funky phenolic-diaphragm horn tweeter around 5 kHz. Like a Klipschorn, there are pretty obvious trouble regions, in this case between 200 and 500 Hz, where the bass module is rolling off and the OB is stealing LF energy from the 12" midrange. The high Q of the Tone Tubby helps here, of course, giving it extra energy in that region.

Some time later, the US agent for Lowther hears about what Thom and I were doing, and he and Nelson Pass came up with their bi-amplified open-baffle Lowther + Tone Tubby setup they start using at shows. This was after Thom declined the Bastanis repping for the Western region of the USA, sent the speakers back, and sold the original pair of Red Tone Tubbies to local guitarists.

A couple years ago I saw and heard the Lowther/TT/Pass setup at the regional Dallas show. It was actually a little worse than that. The Lowther USA guy spotted me wandering through the halls, pulled me into their demo room, and wouldn't let me leave until I had re-balanced the high/low EQ settings for their setup. That was the first time I had seen or heard the Nelson Pass confection. I adjusted the thing so it was more-or-less flat, with a moderate bass emphasis. No measurement gear, just twiddling knobs and guessing on a collection of LP's brought to the show.

I have no idea what kind of sound Nelson Pass likes. Zero. I may have messed up the intended show sound. It was incredibly bright and screechy when I first walked in, so it did need adjusting of some kind. What is the Lowther/TT/Pass setup intended to sound like? I don't know.
User avatar
IslandPink
Amstrad Tower of Power
Posts: 10041
Joined: Tue May 29, 2007 7:01 pm
Location: Denbigh, N.Wales

#899

Post by IslandPink »

It's an odd situation for sure - and your enthusiasm for the TT reds was only part of the picture. I trialed this OB with a cheap Jensen P12N to begin with .
The TT Black sounds so different it seems like it needs different time-alignment ! The differences are in the lower-midrange area, not bass/upper-bass, where the TT is fine .
I would think the TT/Lowther combo would still need a notch filter for the TT , for the 3-4k area, unless you ramped it down fast. The Jensen responded very nicely to that . I have that in place, and can edit as I want, but the TT Black just sounds muddy in the 500-1500Hz region so far.

ps. Nelson's taste ought to be OK, based on what I know of building the F4 and hearing the F5 many times.

It's a shame there are so few drivers in this band that are available and suited to OB . Exotics such as the Fertin are not the right Qts . I keep coming back to the Supravox to be honest ( wish I hadn't sold them ! ) . Also, it's a shame the 285GMF is not replicated by their alnico versions - which have rather different characteristics .

Meanwhile - I think I found the best budget output valves for the Ariels - better than KR300B's , at about £25/pair !
http://www.audio-talk.co.uk/phpBB2/view ... &start=165
"Once you find out ... the Circumstances ; then you can go out"
User avatar
Paul Barker
Social Sevices have been notified
Posts: 8875
Joined: Mon May 21, 2007 9:42 pm

#900

Post by Paul Barker »

IslandPink wrote:. I keep coming back to the Supravox to be honest ( wish I hadn't sold them ! ) .
+1 :cry: :cry: :cry:
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
Post Reply