Something stirs in the Undergrowth

Dedicated to those large boxes at one end of the room
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IslandPink
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#226 Edgar

Post by IslandPink »

Well, you know, your comments on Bruce's system from 2003 stayed with me. Also , every article or comment on forums that I've read from Bruce gives me confidence. He's a guy who understands both the theory and the practice of horn speaker systems . If you dig into the article I linked, and read about the crossover slopes - for instance ; he was building them first with 1st-order slopes because it was easy. Then someone helped him do 2nd or 3rd-order slopes and he tried some of those... but when he listened, and then played the speakers to the 'club' with the steeper crossovers, he didn't like the sound and other people didn't respond as positively . So, he went back to 1st-order slopes. Later, he understood from a theoretical point of view why it works better - but like a good scientist, he believed the evidence first, not the theory .

Hey, even Romy the Cat thinks Bruce is a good bloke - puts him in a club of two, along with Romy !

What you heard for the bass was probably one of his 'monolith' 40Hz horns . There's an article somewhere on those. It's a truncated exponential with one ( maybe two ) fold, I think, firing onto the floor to get the flor gain . Down at that freq, Tractrix isn't so important - there's all sorts of room-modes going on anyway .

The 'Tapped horns' are a new innovation that gives you a smaller package with most of the horn bass attributes - it was the crucial thing that made me realise a 4-way was possible in my room. With these, I can also go up to 130-150Hz , so that allows me to get a slightly better bass/mid horn starting at 110-120Hz instead of the 100Hz horns Bruce used, where he was using 12" or 15" guitar speakers ( EV15M ? ) to get a little lower .
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Paul Barker
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#227

Post by Paul Barker »

I did read that article when it was published and read all Bruces stuff after vsac.

But to actually implement the concept is a big task, which you are obviously well on the way to achieving.

The only other system which held a cnadle to it was Josh's GM100's and that was probably down to his speakers also, he had welded some metal front firing horns which were similarly well integrated .

The sound of the GM100 was pretty well the same as the 212 But I suspect there was something very special about Josh's unusual looking speakers. They were all metal, and on the last day it was quite a job for them carrying them out.
Image

they had to borrow power from the next room as the power from their room alone tripped the fuse at turn on. there was also a line behind which everyone had to stand if I remember rightly.

The Fostex implementations which were prevalent all sounded lifeless and rolled off at the top. Nowadays I see most people are using super tweeters.

I think life is the best word to describe Dr Edgar's stuff it breathed life. After hearing it's sparkle I may aswell have come home, nothing else to say.

The other thing going on was Alen wright was trying to claim he had invented something in a lecture and when he played the actual thing it didn't sound any different to any other reasonable quality push pull amp.

There was a prop forward wearing a frock with oversplashed makeup and dangly ear apparel whose 845 amp blew me away. I was the best sounding amp I heard. I can't remember who the company were but it was a two individual team. I hasten to add it wasn't Steve Bench but the amp was so good it may be they know each other.
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#228

Post by pre65 »

Paul Barker wrote:
There was a prop forward wearing a frock with oversplashed makeup and dangly ear apparel whose 845 amp blew me away. I was the best sounding amp I heard.
There's hope for DTB then. :wink:
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#229 Re: Edgar

Post by chris661 »

IslandPink wrote:<snip>

The 'Tapped horns' are a new innovation that gives you a smaller package with most of the horn bass attributes - it was the crucial thing that made me realise a 4-way was possible in my room. With these, I can also go up to 130-150Hz , so that allows me to get a slightly better bass/mid horn starting at 110-120Hz instead of the 100Hz horns Bruce used, where he was using 12" or 15" guitar speakers ( EV15M ? ) to get a little lower .
Yes, the problem with tapped horns is the limited bandwidth - a rule of thumb is two octaves.

It's all compromise, but they make ideal subwoofers for 80-20Hz.

Any more listening impressions of the TH you built?
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IslandPink
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#230 Re: Edgar

Post by IslandPink »

chris661 wrote:Any more listening impressions of the TH you built?
Not really Chris .
Been working away on the finish/cosmetics on the first one, in-between starting the bass/mid horns . Also, I need to try an amp with lower output impedance , as the 300B amp only has about 1.8R Zout, which alters the response of the tapped horn . Really I should get one of those T-amps , because I can use one for the TV ultimately. If I make an effort to finish the Passlabs F4, I still need to rig up a preamp to drive it. Too many jobs at the moment !

I also need to get some more 18mm MDF for the second unit .

I'll get there eventually, but my progress is never linear .
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#231

Post by chrisby »

Paul Barker wrote:I did read that article when it was published and read all Bruces stuff after vsac.

But to actually implement the concept is a big task, which you are obviously well on the way to achieving.

The only other system which held a cnadle to it was Josh's GM100's and that was probably down to his speakers also, he had welded some metal front firing horns which were similarly well integrated .

The sound of the GM100 was pretty well the same as the 212 But I suspect there was something very special about Josh's unusual looking speakers. They were all metal, and on the last day it was quite a job for them carrying them out.
Image


indeed, they were fun fitting back into the U-Haul trailer along with the amps

they had to borrow power from the next room as the power from their room alone tripped the fuse at turn on. there was also a line behind which everyone had to stand if I remember rightly.
as if the smell of ozone upon entering the room wasn't warning enough that "these aren't your grampa's SETs"
The Fostex implementations which were prevalent all sounded lifeless and rolled off at the top. Nowadays I see most people are using super tweeters.

I think life is the best word to describe Dr Edgar's stuff it breathed life. After hearing it's sparkle I may aswell have come home, nothing else to say.

The other thing going on was Alen wright was trying to claim he had invented something in a lecture and when he played the actual thing it didn't sound any different to any other reasonable quality push pull amp.
funny, I had a different impression on hearing the amp driving Terry Cain's Abbys during a presentation in one of the boardrooms, with a Stellavox as source, IIRC - in other words it worked for me

There was a prop forward wearing a frock with oversplashed makeup and dangly ear apparel whose 845 amp blew me away. I was the best sounding amp I heard. I can't remember who the company were but it was a two individual team. I hasten to add it wasn't Steve Bench but the amp was so good it may be they know each other.
DeHavilland, driving highly modified Lowther based Rethm2s?


yes, that was a silly good combination


Image
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Paul Barker
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#232

Post by Paul Barker »

Chrisby thanks for filling in the details. We must have passed by like ships in the night those three days.

Has there been anything like it since?
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#233

Post by chrisby »

Paul Barker wrote:Chrisby thanks for filling in the details. We must have passed by like ships in the night those three days.

Has there been anything like it since?
There was another VSAC in Vancouver WA in 2008, but while it was a nicer venue, and just as many good and crazy folks presenting and attending, somehow for me the magic was diminished.

The RMAF are a bit far for me to travel and from coverage I've seen trend more to the "carriage trade", and less to frugal / DIY plebes . :wink:
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#234 Update

Post by IslandPink »

Had a bit of a rubbish week , not much progress, but here's latest pic -
"White monolith with horn segments"
That's the first tapped horn almost finished ( just needs final fettling of surface and spray coats ) . Found a paint yesterday that's ideal to match the Azurahorns . It's a satin white radiator paint, in spray can . Sorted !
Note, the front edge of the base panel ( 25mm ply ) is not chequered - that's aliasing from the camera in low-res mode.

Behind you can see two side-pieces of the bass/mid horn .

Re. VSAC, found a great photo yesterday that features amps by Josh Stippich and some amazing horns by Steve Schell ( or at least his cogent drivers ) :

http://www.audioheritage.org/vbulletin/ ... ures/page6
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andrew Ivimey
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#235

Post by andrew Ivimey »

ummmm ?
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#236

Post by andrew Ivimey »

this?!!! - should fit in!
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#237 Re: Update

Post by Mike H »

Flippin' 'eck :shock:

IslandPink wrote:Had a bit of a rubbish week , not much progress
I have lots of those .. Image


 
 
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Paul Barker
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#238

Post by Paul Barker »

Those metal horns Josh had at VSAC were great sounding also.

When you know a small amount of metal working knowledge you have to don your cap to the huge amount of skill knowledge and experience that is electron luv.
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#239

Post by dave dove »

You lot are getting silly ;)

looking forward

dave
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al newall
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#240

Post by al newall »

andrew Ivimey wrote:this?!!! - should fit in!
If thats what it takes to get close to real music.
I may as well give up now and take up knitting or summat.
Much to learn there is.
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