UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Audio (record players, hi-fi etc)

Notices

Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment.

Reply
 
Thread Tools
Old 5th Jan 2017, 7:56 pm   #1
RojDW48
Heptode
 
RojDW48's Avatar
 
Join Date: Jun 2014
Location: Bristol, UK.
Posts: 760
Default Jabez Gough - Welsh wizard?

Along with the 'Davies' cabinet already under discussion I bought this Jabez Gough designed reflecting loudspeaker and I rather like it. It came with the Goodmans driver pictured, which I think was one of the recommended units around 1960. Apparently Jabez sold the plans and buyers fitted their own drivers. It sounded OK but the bass was very feeble. I changed it for the other speaker pictured, which I think is an early Kef B200 (but I could easily be wrong) and that has improved the bass immeasurably. I wonder if any members have experimented with drivers for this design? The cabinet appears to be some form of parallel labyrinth and is a joy for an inveterate fiddler like me as it is easy to extract the angled baffle and try another driver.
Attached Thumbnails
Click image for larger version

Name:	DSC05038.jpg
Views:	186
Size:	39.6 KB
ID:	135424   Click image for larger version

Name:	DSC05039.jpg
Views:	186
Size:	56.9 KB
ID:	135425   Click image for larger version

Name:	DSC05040.jpg
Views:	181
Size:	56.0 KB
ID:	135426   Click image for larger version

Name:	DSC05041.jpg
Views:	169
Size:	59.8 KB
ID:	135427   Click image for larger version

Name:	DSC05042.jpg
Views:	171
Size:	54.2 KB
ID:	135428  

__________________
'....don't go mistaking Paradise for that home across the road!' (Bob Dylan)
RojDW48 is offline   Reply With Quote
Old 5th Jan 2017, 8:11 pm   #2
Hartley118
Heptode
 
Hartley118's Avatar
 
Join Date: Aug 2015
Location: Cambridge, Cambs. UK.
Posts: 687
Default Re: Jabez Gough - Welsh wizard?

Pictured? Not getting pics here.

I seem to remember the Gough speaker getting dramatic publicity in the national press claimed as a previously undiscovered 'miracle' design that broke all previous assumptions.

In practice, I believe it was a folded pipe with a rather distinct bass resonance that was pretty impressive on organ music. Needless to say, the press demonstrations used organ music!

Martin
__________________
BVWS Member
Hartley118 is offline   Reply With Quote
Old 6th Jan 2017, 12:10 am   #3
RojDW48
Heptode
 
RojDW48's Avatar
 
Join Date: Jun 2014
Location: Bristol, UK.
Posts: 760
Default Re: Jabez Gough - Welsh wizard?

I added the pics as a reply because I forgot to add them with the original post and someone more talented (a moderator I assume) has since combined the posts - maybe you looked at that point? Yes there was a lot of fuss made about them at the time and a big demo where one was used to 'fill a concert hall' with sound - it seems to me that any decently designed and made speaker with a good amp and source could do that. Not a miracle but quite nice, even by today's standards. I am hoping that someone might have got a good result with a particular driver with one of these.
__________________
'....don't go mistaking Paradise for that home across the road!' (Bob Dylan)
RojDW48 is offline   Reply With Quote
Old 6th Jan 2017, 7:37 am   #4
Hartley118
Heptode
 
Hartley118's Avatar
 
Join Date: Aug 2015
Location: Cambridge, Cambs. UK.
Posts: 687
Default Re: Jabez Gough - Welsh wizard?

Now I see the pictures. Thanks.

Well, that folded pipe doesn't appear to contain any damping material, so it will have a complex series of prominent resonances to reinforce and colour the sound. I'd expect it to have lots of character!

The Goodmans drive unit looks to have a big high flux magnet, so will have a high efficiency.

You've got a rather rare and rather loud loudspeaker!

Martin
__________________
BVWS Member
Hartley118 is offline   Reply With Quote
Old 6th Jan 2017, 10:27 am   #5
Edward Huggins
Nonode
 
Join Date: Sep 2015
Location: Southwold, Suffolk, UK.
Posts: 2,685
Default Re: Jabez Gough - Welsh wizard?

I remember these. Yes, at around that same time there were a range of DIY speaker designs that were very popular. Who remembers the "Paraline" with its single Elac 9" x 5" high flux speaker? There were also designs using a vertical sewer pipe with an inverted cone at the top and an 8" twin cone unit. A long way from the computer-modelled designs of today...
__________________
Edward.
Edward Huggins is offline   Reply With Quote
Old 6th Jan 2017, 1:58 pm   #6
Whaam68
Pentode
 
Join Date: Feb 2007
Location: Luton, Bedfordshire, UK.
Posts: 126
Default Re: Jabez Gough - Welsh wizard?

There is a youtube video of one of these cabinets playing a bit of jazz here:

https://www.youtube.com/watch?v=8cqvKdy08mk

It sounds quite nice on the video.

And an archive site with info about the speakers here:

https://sites.google.com/site/goughs...icture-gallery

An interesting design.

Mike
Whaam68 is offline   Reply With Quote
Old 6th Jan 2017, 8:02 pm   #7
RojDW48
Heptode
 
RojDW48's Avatar
 
Join Date: Jun 2014
Location: Bristol, UK.
Posts: 760
Default Re: Jabez Gough - Welsh wizard?

Thanks Mike - I had spotted those but it is nice to have them in the thread. I was experimenting with different source materials last night. Martin politely predicts it will have plenty of 'character', but it is definitely fair to describe it as 'peaky'. When I popped on a bit of late 60s reggae there was more than enough activity at around 60Hz! When I have found the right driver or drivers I shall experiment with damping. Any suggestions as to suitable materials would be welcome.
__________________
'....don't go mistaking Paradise for that home across the road!' (Bob Dylan)
RojDW48 is offline   Reply With Quote
Old 6th Jan 2017, 10:02 pm   #8
Edward Huggins
Nonode
 
Join Date: Sep 2015
Location: Southwold, Suffolk, UK.
Posts: 2,685
Default Re: Jabez Gough - Welsh wizard?

Maybe try a Lowther drive unit and modify the baffle cut-out to suit. Failing that a DynaAudio or Morel full range driver - but they are very expensive. For damping use clad-on panels.
__________________
Edward.
Edward Huggins is offline   Reply With Quote
Old 7th Jan 2017, 12:52 am   #9
RojDW48
Heptode
 
RojDW48's Avatar
 
Join Date: Jun 2014
Location: Bristol, UK.
Posts: 760
Default Re: Jabez Gough - Welsh wizard?

Phew! that's a bit on the dear side. I have considered the possibility that a really good driver might be the way forward and what I might do is 'borrow' one from one of my Harbeth Mk1 HL monitors to see if this old Welsh bit of innovation can actually bear comparison to other, more conventional, designs. Not sure what you mean by 'clad on panels'?
__________________
'....don't go mistaking Paradise for that home across the road!' (Bob Dylan)
RojDW48 is offline   Reply With Quote
Old 7th Jan 2017, 6:48 am   #10
Dr Wobble
Nonode
 
Dr Wobble's Avatar
 
Join Date: Jul 2009
Location: Sleaford, Lincs. UK.
Posts: 2,236
Default Re: Jabez Gough - Welsh wizard?

The surround in pic 5 looks on the way out, wouldn't crank them up too much.

Andy.
__________________
Curiosity hasn't killed this cat...so far.
Dr Wobble is offline   Reply With Quote
Old 7th Jan 2017, 8:32 am   #11
Whaam68
Pentode
 
Join Date: Feb 2007
Location: Luton, Bedfordshire, UK.
Posts: 126
Default Re: Jabez Gough - Welsh wizard?

Just a thought but at the time this cabinet was designed amps would have all had tone controls. If you have an amp/preamp with them I'd try the drivers it came with some bass lift applied. Similarly are the Goodmans 15ohm? If so they may need matching to an amp with a 15 ohm output impedence. Might be interesting to try valve vs solid state? Suggestions I've seen for damping these were fibreglass roll stuffed under the driver or damping one side only of the line under the driver. Good luck!
Mike
Whaam68 is offline   Reply With Quote
Old 7th Jan 2017, 9:05 am   #12
Edward Huggins
Nonode
 
Join Date: Sep 2015
Location: Southwold, Suffolk, UK.
Posts: 2,685
Default Re: Jabez Gough - Welsh wizard?

Quote:
Originally Posted by RojDW48 View Post
Phew! that's a bit on the dear side. I have considered the possibility that a really good driver might be the way forward and what I might do is 'borrow' one from one of my Harbeth Mk1 HL monitors to see if this old Welsh bit of innovation can actually bear comparison to other, more conventional, designs. Not sure what you mean by 'clad on panels'?
It's possible to use self adhesive, high density panels (used for car noise deadening), which I thought might be an easier solution rather than wool or loose materials. You will need a large full-range driver or one with tweeters across the axis, but these are very hard to obaian now. When this cabinet was designed, 12" full range units, some using a whizzer cone, were far more readily available. I liked them for what they were, as they eliminated insertion loss caused by cross-overs.
__________________
Edward.
Edward Huggins is offline   Reply With Quote
Old 7th Jan 2017, 3:23 pm   #13
RojDW48
Heptode
 
RojDW48's Avatar
 
Join Date: Jun 2014
Location: Bristol, UK.
Posts: 760
Default Re: Jabez Gough - Welsh wizard?

You are right Andy - the suspension is a bit tired. I have identified that driver as a fairly ancient Celestion - it doesn't have enough mid range performance to be much use in the end but it did serve to prove that the cab is capable of sufficient 'bottom'

Mike, the pre-amp is a Radford SC24 with lots of tone controls and the amp is a Radford Rennaisance STA35 so there is plenty of scope for compensation. I did play around with the old Goodmans but it was a bit of a lost cause.

Thanks for the clarification Edward. I used to have a nice little Goodmans Axiette with a whizzer cone, which might well have been the very thing but I must have given it away or incorporated it into another project because I can't find it anywhere.
__________________
'....don't go mistaking Paradise for that home across the road!' (Bob Dylan)
RojDW48 is offline   Reply With Quote
Old 7th Jan 2017, 4:22 pm   #14
Edward Huggins
Nonode
 
Join Date: Sep 2015
Location: Southwold, Suffolk, UK.
Posts: 2,685
Default Re: Jabez Gough - Welsh wizard?

One option is to set a 3" Dome tweeter on a slim aluminium sub-baffle across the axis of the 12" Celestion, use a good Solon 2.2uF cap as the High Pass filter.
Or another low(ish) cost option, go buy a 4 ohm car audio speaker. Those 9" x6" units have very high power handling, low cone resonant frequency and a concentric tweeter (inc. crossover.)
__________________
Edward.
Edward Huggins is offline   Reply With Quote
Old 7th Jan 2017, 4:42 pm   #15
Hartley118
Heptode
 
Hartley118's Avatar
 
Join Date: Aug 2015
Location: Cambridge, Cambs. UK.
Posts: 687
Default Re: Jabez Gough - Welsh wizard?

I wouldn't expect you to be too troubled by flexural panel resonances - with the dual open ended pipes, the internal pressures won't be very great compared with a closed box or reflex design and it looks to be a pretty rigid structure. The main colorations will arise from the air column resonances in the folded pipes, much like organ pipe resonances. You'll get a comprehensive range of harmonically related resonances, the lowest frequency resonance being where the pipe length is a quarter wavelength. That may account for the strong 60 Hz performance - generally good for disco, but a bit high in frequency for reggae bass!

Then of course you have the pipe cross-mode resonances, fairly well spread in frequency if the pipe is tapered, but prominent like a fat drainpipe if it has parallel sides. To control the air column resonances, a soft absorbent cushion in each of the open ends should help because the opening is the point of maximum sound 'particle velocity' where an absorbent has maximum effect. For the cross- mode resonances, an absorbent curtain hung down the middle of each pipe would be effective (particle velocity is a maximum away from the pipe walls). Of course, damping these resonances will make the character rather less exciting, but it should sound more realistic on a wider range of music material.

So, as you say, there's lots of scope for experiment! I suspect you'll get far more control over coloration with this use of absorbent materials than by changing the driver. However, I'd expect a driver with a strong top response to give you the best balanced sound because of all the LF reinforcement from Mr Gough's pipes.

Martin
__________________
BVWS Member
Hartley118 is offline   Reply With Quote
Old 7th Jan 2017, 7:52 pm   #16
RojDW48
Heptode
 
RojDW48's Avatar
 
Join Date: Jun 2014
Location: Bristol, UK.
Posts: 760
Default Re: Jabez Gough - Welsh wizard?

I mocked up another baffle and fitted a Kef B160 (SP1366) which smoothed out many more wrinkles than I had hoped, to be honest. I also stuffed the ends of the pipe with some cushion filler, as suggested by Martin. There is a much nicer balance now between mid range and bass. The SP1366 is a curious thing - there appears to be space for a tweeter in the centre of the cone. All I could find out on the net was that deeply confused people are searching for tweeters which might fit in the several versions of the B160! Has anyone used these little drivers and fitted tweeters? What does the fact that there is a hole full of fresh air through the centre of this driver do to its performance? Does it have to be fitted with a tweeter?

Alternatively, I rather like Edward's suggestion of a decent car speaker with all the bells and whistles included - any recommendations?
__________________
'....don't go mistaking Paradise for that home across the road!' (Bob Dylan)
RojDW48 is offline   Reply With Quote
Old 12th Jan 2017, 12:18 am   #17
RojDW48
Heptode
 
RojDW48's Avatar
 
Join Date: Jun 2014
Location: Bristol, UK.
Posts: 760
Default Re: Jabez Gough - Welsh wizard?

I have now set up the speaker with the aforementioned Kef B160 and a T27 fed by an old 70s RS x-over and it's making a rather nice noise. I plugged the hole in the magnet with some blu-tak (Burning Spear's bassman was producing cone excursions that were beginning to look like actual trips to the seaside!) and that seems to have calmed things down nicely.

I know it's outside our metier but it would be nice to know if anyone has experience of good multi-element car audio drivers in a domestic setting. It's all a bit crowded behind that little baffle just now.
__________________
'....don't go mistaking Paradise for that home across the road!' (Bob Dylan)
RojDW48 is offline   Reply With Quote
Old 12th Jan 2017, 5:31 am   #18
Dr Wobble
Nonode
 
Dr Wobble's Avatar
 
Join Date: Jul 2009
Location: Sleaford, Lincs. UK.
Posts: 2,236
Default Re: Jabez Gough - Welsh wizard?

I have a NOS Goodman's axiom 8, full range speaker I think, if any use to you Roger if you want to give it a whirl.

Andy.
__________________
Curiosity hasn't killed this cat...so far.
Dr Wobble is offline   Reply With Quote
Old 12th Jan 2017, 9:25 am   #19
Edward Huggins
Nonode
 
Join Date: Sep 2015
Location: Southwold, Suffolk, UK.
Posts: 2,685
Default Re: Jabez Gough - Welsh wizard?

That's a very, very nice speaker (and NOS!) but probably best suited to a standard reflex design.
__________________
Edward.
Edward Huggins is offline   Reply With Quote
Old 12th Jan 2017, 2:29 pm   #20
RojDW48
Heptode
 
RojDW48's Avatar
 
Join Date: Jun 2014
Location: Bristol, UK.
Posts: 760
Default Re: Jabez Gough - Welsh wizard?

That's an outstanding offer Andy! PM sent.
__________________
'....don't go mistaking Paradise for that home across the road!' (Bob Dylan)
RojDW48 is offline   Reply With Quote
Reply

Thread Tools



All times are GMT. The time now is 5:26 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at http://www.vintage-radio.net.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright ©2002 - 2017, Paul Stenning.