Celestion HF 1300 expert needed

[bumpy]

After more than a year trying to sell them for about £20 I am now stripping a pair of vintage Radford speakers and selling the parts off separately.

At present I am a bit stuck removing the HF1300. Its seems to be glued in place and I don't want to break anything.

I attach pictures of the front and back and I cant at present even work out if it comes out forwards or backwards. I have removed the screws from the rear bracket, but am loathe to touch the 3 screws on the front. It all seems very solidly in place at present.

PS Seems to be stopping me upload pictures at present - will try again later

[bumpy]

At the file upload manager I just get a little wheel rotating with a ? beside it. Whats happening

[walpurgis]

Definitely need photos.

If they are from Radfords, they may be the 16 ohm metal bodied version and more desirable than the plastic ones.

[bumpy]

Definitely need photos.

If they are from Radfords, they may be the 16 ohm metal bodied version and more desirable than the plastic ones.

They do seem to have metal bodies and the front looks different to all the images on Google ?

Still cant upload pictures There is just the little rotation wheel and ? and the 'add files' button is inactive

[bumpy]

Looks like I need a moderator to help

[spendorman]

Looks like I need a moderator to help

I'm doing nothing at the moment, I can PM you with my email address, you send me the pics, and I can put them up.

[bumpy]

Pictures sent Alex. Thanks so much.

I would still like to resolve this as I have other pictures to post :(

[spendorman]

Just putting pics here as attachments.

2152221523

[spendorman]

They do look like HF1300, but the front grilles seem different to the usual. They are mounted in a similar way to that used on the BBC LS3/6 and early Rogers Export monitors, just that bracket on the back. Just remove the screw in the back of the magnet and the unit should slide out. Avoid straining the connection wires though.

[bumpy]

Thanks again Alex .

The 'glue' holding the tweeters tight seems to be some sort of vintage putty that is now pretty solid but can be broken away gently at its edges. Probably a Radford trade secret :)

[bumpy]

I have removed the brackets. Each driver is marked T314. and both measure about 12 ohms.

Still firmly held, so if we are sure they come out through the front then I will gently chip away at the putty.

[spendorman]

Yes, looking again at your pics, I see what looks a bit like putty. In the LS3/6 and Export monitors, there is thin felt around the inside of the tweeter hole, and that makes a sort of seal. It seems a bit of a shame breaking them, they should sell on ebay, possibly for more that you get for the parts.

It looks like you could remove quite a lot of the visible putty, then perhaps try some white spirit to soften the sealant.

[bumpy]

Sorry, but my 'reply with quote' is not working either????

Yes I'm very sorry to break them up but I even tried E bay at £20. Cost of postage too much I suppose. AND the wife has been giving me grief for them sitting around in the back bedroom for nearly two years. Incidentally the cabinets are solid mahogany and I will sneak them into the back of the shed.

I will take small chippings of the putty and put them in different solvents and see if it softens.

[spendorman]

Apologies for the pic quality, but you can see that the two tweeters are mounted in a similar way in my LS3/6 / Export Monitors. HF1300 tweeter and HF2000 used as supertweeter

https://farm9.staticflickr.com/8480/29302983266_00f1b41b3a_k.jpg (https://flic.kr/p/LDps2q)DSCF9577 (2) (https://flic.kr/p/LDps2q) by A60man (https://www.flickr.com/photos/41679262@N02/), on Flickr

[bumpy]

Thanks Alex, but that pussy cat is a bit of an extreme way to dampen the cabinets :)

[spendorman]

Sorry, but my 'reply with quote' is not working either????

Yes I'm very sorry to break them up but I even tried E bay at £20. Cost of postage too much I suppose. AND the wife has been giving me grief for them sitting around in the back bedroom for nearly two years. Incidentally the cabinets are solid mahogany and I will sneak them into the back of the shed.

I will take small chippings of the putty and put them in different solvents and see if it softens.

If you are going to keep the cabinets, why not keep the units in there too. I reckon that Radford speakers are going to rise in value in the future. Their valve amps are certainly very sought after, transistors ones not so much, but even those have risen in value recently (as long as they are working). I invested in a second hand STA25 III many years ago, was £150, now worth over £1000.

[spendorman]

Thanks Alex, but that pussy cat is a bit of an extreme way to dampen the cabinets :)

Yes, notice her size, she was a big cat! shame she's no longer with us. The HF1300 should come out either from front or back. Either way, as I mentioned, be careful not to strain those wires. I suppose that you could carefully cut away the baffle board, but I suspect that it is fairly thick and tough wood. Masking tape could be used to cover the front of the tweeters.

!2 Ohms resistance is just about right for the 16 Ohm HF1300

[struth]

memory says they are fitted with a gasket that usually goes hard and grips solid. Usual method is to fit an oversized screw in on of holes and pull/push and it should free up

[bumpy]

The putty is unaffected by all normal household solvents, so I am chipping it away slowly, being VERY careful around the wires - could be at this some time :)

[spendorman]

Perhaps try a little WD40.

Those front metal grilles puzzle me a bit, even the old GEC tweeter from which I think the HF1300 is derived, have "normal" looking grilles.

http://soundup.ru/images/stories/archive/Classic/speakers/gec-genalex-fr-bcs-1851-8-aluminum-cone-speaker-1852-tweeter/gec-genalex-fr-bcs-1851-8-cone-1852-tweeter-8.jpg

http://soundup.ru/images/stories/archive/Classic/speakers/gec-genalex-fr-bcs-1851-8-aluminum-cone-speaker-1852-tweeter/gec-genalex-fr-bcs-1851-8-cone-1852-tweeter-7.jpg

[spendorman]

I might be wrong about the HF1300 being derived from the GEC tweeter, because here in post No. 3 it says that the GEC tweeter was a rebranded Celestion HF1300

http://www.diyaudio.com/forums/full-range/103246-gec-metal-cone-speakers-kelly-ribbon-tweeters.html

The poster says that he worked at GEC Hirst Research Labs where the GEC Metal Cone speaker was developed. Coincidentally, I worked a few miles from there, at GEC Marconi, but that was from the 80's to about 2004.

[bumpy]

Those front metal grilles puzzle me a bit

Yes that remains a mystery - I cant find a comparable image on Google.

Strange.

[bumpy]

Yes that remains a mystery - I cant find a comparable image on Google.

Strange.

Here's a close up

[spendorman]

I presume that these are the Radford bookshelf speakers? My friend has a pair, when I next speak to him I will ask what the HF1300 grilles look like. He also has other speakers with 1300's. I must have about 12 pairs of speakers that use the HF1300, eg. several pairs of Spendor BC1, BC2, Rogers LS3/6, Home made using EMI 14x9" 5" mid, HF1300 and Coles 4001g, several pairs of B&W DM1, DM2, a DM3, that uses the 1400 (1300 with a bigger magnet), home made using KEF B200, HF1300 and Coles, several pairs of Celestion Ditton 15 (uses the cheaper 1300 with small magnet), and probably some other speakers that I have forgotten about/

[bumpy]

Google image search found this :)

https://i.ebayimg.com/images/g/Q2MAAOxy4fVTDeWr/s-l300.jpg

[spendorman]

Google image search found this :)

https://i.ebayimg.com/images/g/Q2MAAOxy4fVTDeWr/s-l300.jpg

That looks like it would suitable for my 28 year old Volvo, except the 5 stud fixing!

[bumpy]

I presume that these are the Radford bookshelf speakers? My friend has a pair, when I next speak to him I will ask what the HF1300 grilles look like. He also has other speakers with 1300's. I must have about 12 pairs of speakers that use the HF1300, eg. several pairs of Spendor BC1, BC2, Rogers LS3/6, Home made using EMI 14x9" 5" mid, HF1300 and Coles 4001g, several pairs of B&W DM1, DM2, a DM3, that uses the 1400 (1300 with a bigger magnet), home made usihf KEF B200, HF130 and Coles, seveal pairs of Celestion Ditton 15 (uses the cheaper 1300 with smalled magnet), and probably some other speakers that I have forgotten about/

Thanks Alex. The speakers are simply called Radford BLS.

if its of any help the series capacitor attached to the tweeter is an 8uF electrolytic made by Plessey and dated 1964.

[spendorman]

"BLS", presumably Bookshelf Loud Speaker. I have emailed your 1300 grille image to my friend. I guess that he'd take yours if you ever went near Sheffield where he lives.

[walpurgis]

It doesn't look exactly like an HF1300, because it isn't one. It's a T314 as marked. Obviously it is related to the HF1300. There were other closely related tweeters from Celestion too.

[walpurgis]

As I say. There were other related tweeters. Here are my T718's.

http://i64.tinypic.com/260q652.jpg

I've never seen another pair. Note the short throat in front of the diffuser/phase corrector.

[Edward]

I use to have Radford speakers for ages, sounded fantastic but gave them to a mate years ago when I got some Harbeths. The Radfords had 3 drivers but can't recall what model they were. About 1.2m high, tall slim things with solid wood cabs. From what I understand they are still around but unused. Are they worth getting back or am I just asking for trouble?

[walpurgis]

Radford turned out several designs. If my memory serves me, those that had three drivers often used all Goodmans drive units. There was also one using Goodmans bass drivers and tweeters, with a largish dome mid unit, which I think was a German job.

If they are still functional, they could be worth having back. But they won't live up to comparison to Harbeths.

[Edward]

Thanks Geoff. I may well see what's what on the old Radfords. Yes loved the Harbeths but sold them off for silly low money. Big regret there.


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[walpurgis]

I seem to recall seeing early Peerless dome tweeters in some as well. Their speakers were assembled near where I worked many (many) years ago and I'd pop in now and then to buy odds and ends, usually Decca drive units. (used to drop by Lockwood (Tannoy) too, when they were in Harrow).

[bumpy]

It doesn't look exactly like an HF1300, because it isn't one. It's a T314 as marked. Obviously it is related to the HF1300. There were other closely related tweeters from Celestion too.

Thanks Geoff, that solves the mystery. It looks like Radford commissioned their own version of the HF1300 namely the T134 - certainly they still refer to it as an HF1300 on the rear nameplate. What would be certain is that Radford would not have commissioned a driver that sounded worse than the original HF1300.

When its out of its mounting I will take more pictures. Can anyone suggest a site where I can lodge the pictures, and a potted description, for prosperity (Radford, Celestion etc)? It would be a shame to loose this history.

[walpurgis]

Can anyone suggest a site where I can lodge the pictures, and a potted description, for prosperity (Radford, Celestion etc)? It would be a shame to loose this history.

Here? In the 'Past Masters' section.

[spendorman]

I believe all the 1300's had A "T" number, I have never followed them, even the HF1400 has a "T" number. Later today, I might look to see if the T number appears on HF2000.

Regarding as site to recording the history, as Geoff says "Here? In the 'Past Masters' section." But you might consider the Yahoo Radford group as well.

[spendorman]

Just looked at three of my HF2000's, none of them have any number on the back, however, a search on the internet, resulted in finding these with a T number:

2153121532

[walpurgis]

The PA horn tweeters are also 'T' designated as per T1360 model. It seems a universal thing I think. The 'T' no doubt denoting 'Tweeter'!

http://i68.tinypic.com/n4gmt4.png

[spendorman]

I'll look out a HF1400, see is there is a T number on that

[TazSob]

Found this on the web about early Radfords https://www.vintage-radio.net/forum/showthread.php?t=55859

Post #10 is from a chap that worked at Radford in the 60's

[spendorman]

I sent your photo of the strange HF1300 grille to my friend that has some similar Radfords, he said that he can't see the metal grilles on his as there doesn't seem to be an easy way to remove the front cloth without damage. He also has a pair of Radford baffles containing B139 and HF1300's, those have the normal HF1300 metal grilles.

[bumpy]

I sent your photo of the strange HF1300 grille to my friend that has some similar Radfords, he said that he can't see the metal grilles on his as there doesn't seem to be an easy way to remove the front cloth without damage. He also has a pair of Radford baffles containing B139 and HF1300's, those have the normal HF1300 metal grilles.

Looks like Radford decided to not use the front plate to mount the drivers (presumably for sonic reasons), so they removed the whole assembly shown in the attached picture and replaced it with the more simple grille. They then anchored the drivers using the rear bracket and putty. I have to say that the tweeter assembly in place seems totally inner to vibrations when tapped.

http://voicecoil.free.fr/images/Resize%20of%20Resize%20of%20P1040033.JPG

[spendorman]

From memory, the dome in you picture does not look like domes in 1300's that I have taken apart.

They looked more like this:

https://images.duckduckgo.com/iu/?u=http%3A%2F%2Fvoicecoil.free.fr%2Fimages%2Fhf130 0%2FResize%2520of%2520P1040344.JPG&f=1

[walpurgis]

From memory, the dome in you picture does not look like domes in 1300's that I have taken apart.

They looked more like this:

https://images.duckduckgo.com/iu/?u=http%3A%2F%2Fvoicecoil.free.fr%2Fimages%2Fhf130 0%2FResize%2520of%2520P1040344.JPG&f=1

That is correct. The HF1300 phenolic diaphragm is more or less conical and sits closely behind the phase correction grille which is also conical in profile.

[bumpy]

From memory, the dome in you picture does not look like domes in 1300's that I have taken apart.

They looked more like this:

https://images.duckduckgo.com/iu/?u=http%3A%2F%2Fvoicecoil.free.fr%2Fimages%2Fhf130 0%2FResize%2520of%2520P1040344.JPG&f=1

I thought it looked a bit odd :) Serves me right for lifting images from Google that are wrongly labelled.

[bumpy]

That is correct. The HF1300 phenolic diaphragm is more or less conical and sits closely behind the phase correction grille which is also conical in profile.

Interesting you called the diaphragm phenolic - what colour does it normally look?

[spendorman]

I'd be interested to know what that picture of yours is of.

The front of the HF1300 dome/ cone is usually painted black, some silver painted though.

I think, but can't fully remember, that the back is a brown phenolic colour.

[bumpy]

I'd be interested to know what that picture of yours is of.

The front of the HF1300 dome/ cone is usually painted black, some silver painted though.

I think, but can't fully remember, that the back is a brown phenolic colour.

Here's the link to where the picture came from

http://www.ebay.co.uk/itm/REPLACEMENT-DIAPHRAGM-tweeter-CELESTION-HF1300-DITTON-25-4-OHM-and-many-more-/221975710586

I only asked about the colour of the dome as mine is silver. Did they ever make a metallic dome in addition to the phenolic?

[spendorman]

Here's the link to where the picture came from

http://www.ebay.co.uk/itm/REPLACEMENT-DIAPHRAGM-tweeter-CELESTION-HF1300-DITTON-25-4-OHM-and-many-more-/221975710586

I only asked about the colour of the dome as mine is silver. Did they ever make a metallic dome in addition to the phenolic?

All explained, I think, that ebay listing is for a non standard replacement diaphragm.

Don't think the HF1300 was ever produced with a metal diaphragm

[bumpy]

Thanks

Another question - were the early HF1300s fitted with alnico magnets?

[spendorman]

Thanks

Another question - were the early HF1300s fitted with alnico magnets?

Depends on what one means by early, the ones used in Ditton 10, Ditton 15, County etc. had a smaller ceramic magnet, and were lower impedance 4 Ohm, like these:

https://images.duckduckgo.com/iu/?u=http%3A%2F%2Fimg.canuckaudiomart.com%2Fuploads% 2Flarge%2F389748-celestion_hf1300_tweetersspeakers4_ohms.jpg&f=1

To me, the really interesting one is the HF1400, has a bigger magnet than any of the others, used in some BBC speakers and B&W DM3. I would like to obtain more information on them. I have a pair of DM3's and a spare pair of HF1400's. I am tempted to try the 1400's in my LS3/6's, I suspect that they would be a bit more sensitive, but that is easily adjusted using the taps on the autotransformer.

[SPS]

Depends on what one means by early, the ones used in Ditton 10, Ditton 15, County etc. had a smaller ceramic magnet, and were lower impedance 4 Ohm, like these:

https://images.duckduckgo.com/iu/?u=http%3A%2F%2Fimg.canuckaudiomart.com%2Fuploads% 2Flarge%2F389748-celestion_hf1300_tweetersspeakers4_ohms.jpg&f=1

To me, the really interesting one is the HF1400, has a bigger magnet than any of the others, used in some BBC speakers and B&W DM3. I would like to obtain more information on them. I have a pair of DM3's and a spare pair of HF1400's. I am tempted to try the 1400's in my LS3/6's, I suspect that they would be a bit more sensitive, but that is easily adjusted using the taps on the autotransformer.

I have a pair of very large magnet version in a LS5/1a... where these the 1400 ?

[spendorman]

Just looking here

http://www.markhennessy.co.uk/rogers/others.htm

Seems like the LS5/5 used the HF1400

Yours, seem to have 2 x HF1300

[SPS]

Just looking here

http://www.markhennessy.co.uk/rogers/others.htm

Seems like the LS5/5 used the HF1400

Yours, seem to have 2 x HF1300

Thanks for linking that it's an interesting read
The difference in size and efficiency is staggering between the 70's versions I have and these early sixtys bbc 'specials'
I also have a pair of the gec versions which sound very nice and are still quite efficient
Thanks

[walpurgis]

Yes. Those were the days. None of yer nasty ferrofluid nonsense back then :).

Even by modern standards, the HF1300 tweeter is quite remarkable. Its ability to show transparency and render detail through the upper mid and into the treble region is outstanding. It reproduces ambience superbly.

It can show a touch of hardness and is tonally awkward to integrate with other drivers.

I built these around 1980, they worked rather well. 6 1/2 inch Audax bass/mid if I recall.

http://i68.tinypic.com/2qd9bu8.jpg

The HF1300 tweeters came from Denys Trickett. Anybody remember him?

[bumpy]

I suppose my question should have been "Were HF1300s ever supplied with alnico magnets?"

[walpurgis]

I suppose my question should have been "Were HF1300s ever supplied with alnico magnets?"

Yes. I have a 16 ohm pair.

[spendorman]

"Denys Trickett. Anybody remember him?"

Yes, never met him though, remember that one had to go up stairs to his place.

[bumpy]

Yes. I have a 16 ohm pair.

Cool.
Is there any way of knowing?

[spendorman]

I believe unless the tweeter magnets look like this:

https://images.duckduckgo.com/iu/?u=http%3A%2F%2Fimg.canuckaudiomart.com%2Fuploads% 2Flarge%2F389748-celestion_hf1300_tweetersspeakers4_ohms.jpg&f=1

They are all Alnico.