Tannoy Chatsworth Gold

[divedeepdog]

A tatty pair off ebay arrived today, one DOA, but a tweak to the 4 pin plug seems to have sorted it (for now)

The cabinets are scratched and show signs of their 50 odd years, but appear solid. I've not had the drivers out yet, all too keen to hear what they can do.

Initial impressions, sat on 3 bean can stands is really nice bass, there's a nice thwack that Eaton's don't match. Think they need another 3" in height for the pinpoint image, tweeter is below ear height.

Plans?
Before I build new cabs, I can refurbish the originals, thankfully older veneer is thicker and will stand a good sanding.

New fabric required, there's a tear in one. I've seen the ebay stuff, any other suppliers?

Thinking of improving the cabinets, thoughts about 12mm front baffle and sitting the driver on the face? Will I gain a few inches volume for internal 'shelves' and/ or battens to add rigidity?

The padding on the back panel is pretty tight against the back of the driver, not something I've noticed on other models?

Lots of other threads here about suggesting leaving the crossovers alone, but I've possibly got an issue with a 4 pin connector, expensive new replacement on the Bay?

Speaker binding posts, I replaced the Eatons, had to drill the holes out to accept them, however, will replacing the golds adversely affect value?

I'll take some pics tomorrow, for interest original advert here;

https://www.ebay.co.uk/itm/TANNOY-VINATGE-CHATSWORTH-SPEAKERS-12-GOLDS-1960S/143596128763?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

 

[divedeepdog]

IMG_6221 by mark leatherland, on Flickr
IMG_6219 by mark leatherland, on Flickr

 

[ToTo Man]

The padding on the back panel is pretty tight against the back of the driver, not something I've noticed on other models?

My Chatsworth and Lancasters both had imprints of the magnet cover in the padding on the back panel, - to be expected given the relatively shallow depth of the cab.

 

[Tony L]

Cabs look saveable. I’m sure someone with woodworking knowledge could advise how to breathe new life into the finish. Shame about the grille, but again there are close equivalents. If it was me I’d just start by restoring as best you can and then get used to them for a few months. I’d do nothing structural to the cabs, nothing to the speakers beyond thoroughly cleaning the crossover switches and speaker connections with Deoxit. Really work those level and roll-off switches with Deoxit as they can tarnish over the years. Beyond that, just enjoy for a while. Adapt to their voice, find out why so many of us like them, or why some oddballs hate them.

 

[divedeepdog]

I may have an idea with the woodwork .
I'm already there with the Eatons @ appreciating what Tannoys do, these move it on again already.

Years with the amazing Avondale Revelations, I don't think I could get more divergent box speakers if I tried. The Revs do that 'Where on earth did that bass come from', Tannoys are revealing what was going off in the studio with overdubs and mixes.

I'll order Detoxit, had a quick play with Rew ,Tear side has a dip @ 1350hz. Working on posting graphs, but advice on anything useful appreciated

 

[divedeepdog]

IMG_6222 by mark leatherland, on Flickr

Measurements taken 30cm away from driver centre.
At least its easy to swap X-overs to see if the dip follows it or driver.
As we're learning from the government, adjusting the scale on the left can alter how things look, again advice on whats reasonable welcomed. I'm not a critical measurist, I haven't tried other speakers beyond integrating the sub.

 

[ToTo Man]

@divedeepdog , I was about to enviously congratulate you on lucking out on a near perfect matched pair of Tannoy drivers... and then I noticed the axis scale and smoothing! I suggest clicking the 'cog' icon at the top right and changing the smoothing to 1/12, and then click the axis button that's adjacent to it and change the scale so that you only have a difference of 60dB between the lowest and highest value. You could also change the min/max frequencies to 20Hz-to-20kHz. This will make the graph easier to read.

 

[divedeepdog]

Any better (to read)
IMG_6225 by mark leatherland, on Flickr

As I said, I've never measured individual speakers, just in the seated position for adjusting the sub. All speakers I've had have dipped @ 70hz, always assumed its a room thing? The difference in bass could also be attributed to location, one speaker's stuck between rack and TV, the other has a bit of space at the side.

 

[ToTo Man]

Yes, better, but your vertical axis scale is still very large and I'm not sure how it's possible to get negative dB readings? What microphone are you using and did you calibrate it using the 'SPL Meter' panel in REW?

Here's an example of one of my measurements using a UMIK-1 microphone. This measurement was taken at my listening seat, hence the large differences in bass response. See how the curves stop at about 55dB? The background noise floor of a typical living room is usually anything between 35dB and 50dB so it's pointless trying to measure at levels lower than this:

The following measurement was taken with the microphone almost touching the grille cloth, trying to eliminate as much of the room as possible:

To determine how well matched a pair of drivers are, you really need to measure both cabinets in the exact same location of the room, and by exact I literally mean within a few mm's of accuracy. This will remove room variance. If this is too much hassle then keep the speakers where they are but measure with the microphone as close to the grille cloth as possible, because this will at least make the treble and mid frequencies comparable, but the bass will probably still show room differences.

The good news is that, based on the Tannoy drivers I have measured myself, you are unlikely to find significant variations in the frequencies produced by the bass cone (i.e. 20Hz-1kHz), most of the differences come from the tweeter (i.e. 1kHz-20kHz).

From the graphs you've posted, it looks like you'd improve the matching by either increasing the Energy knob on the Green speaker, decreasing the Energy knob on the Purple speaker, or, if the difference in level is also present in the bass frequencies, then a better solution may be to adjust the Balance control on your amp to bring the overall level of the Purple speaker down to match the Green one.

In order to determine which solution is best, you really need to repeat the measurements with both speakers in the exact same spot to remove the room being a possible cause of the variation.

 

[divedeepdog]

I've got Velodyne mic, looks the same as the UMIK-1, but not calibrated . The purpose is to eliminate any glaring problems and learn a bit along the way. Bit awkward on the bean can stands, I should look through the off-cuts pile and build some stands while the weather's favourable, probably more productive use of time.

Knee jerk reaction is buy new and replace, but Tony's mantra of keep original, make good whats there is wise. Contact cleaner on the way, small step at a time

 

[Tony L]

FWIW I tried the close-mic approach and I don’t trust it at all. I deliberately positioned the stand so it was easily repeatable either side with the stand feet hard against the front, offset by a specific number of mm to visually centre the mic etc (it’s a good quality stand so stays put when its carried). Even so I just didn’t trust the measurements as a) due to the Tannoy’s directionality and how the horn works the sound just isn’t aligned at that distance, and b) I suspect I was also getting a reflection from the stand and mic.

Far better to measure at a metre or more leaving the mic stand where it is and to shift the speakers. Maybe measure right in the centre of the room as that way any reflections are the longest time away possible. It doesn’t matter what the measurement looks like, just that they are close to one another. I use packing tape on the carpet for this sort of thing so I can position the speakers accurately. Also mark the position of the ‘other’ speaker so you have it in the same place for each measurement, i.e. you aren’t altering the room acoustic at all, and be in the same place yourself. That should produce a reasonably accurate picture.

Finally using just one speaker in this position try both crossovers, i.e. if there is a discrepancy (there will be, because Tannoy), it will help you identify its origin, i.e. it is pointless going down the rabbit hole of compression driver alignment if you have a dirty switch or wildly off-spec capacitor somewhere. For this it tends to be easier just to swap the whole back door over if that is where the crossover is fitted.

 

[divedeepdog]

Bit of progress yesterday, veneer wet to raise the grain and scratches between sanding.
IMG_6325 by mark leatherland, on Flickr

Has anyone removed the front baffle? Its looks like its screwed on from the inside, is the wooden 'picture frame' attached to the baffle only? It would make replacing the fabric much easier if it comes out together.

 

[divedeepdog]

Mystery over. Wooden frame screwed from behind covering baffle screws.
IMG_6328 by mark leatherland, on Flickr

Looking for fabric now.

 

[cooky1257]

The original stuff was either Tygan or Vynair glued to the baffle, it was great to use as you could tighten it up with a hairdryer on hot.
Trouble is whatever the fabric replacement, you are stuck with it for listening if you repeat the existing mounting method. I suppose you could mount it onto the frame instead and just tidy up the old glue/baffles to look presentable.
FWIW the cabs I'm converting to Balmorals came with the (very attractive)heavy oatmeal type stuff sold by a well known eBay seller and it definitely isn't transparent despite assurances.

 

[calorgas]

It's a shame that the Sid Chaplin / retrospecialist stuff isn't available in large sizes anymore, that's what I'd used for the grilles on the 12" Gold ply cabs I had. Can't say for sure that it was 100% acoustically transparent but it didn't seem to make any obvious difference when on (and looked great to me).

I tried some cheap-ish 'vintage style' grille material (from Hong Kong iirc, marketed as replacements for Fender/Marshall units) and that's so thin that it's almost visually transparent as well as acoustically transparent. Disappointing it's so thin really, as it's otherwise not bad looking although nowhere near a match for original Tannoy material.

 

[divedeepdog]

I may go new baffle and removable grill, leave the originals as they are? The bolts for the drivers are hanging on by a splinter.

I suspect new cabs are in the future.

 

[Tigerjones]

Thoroughly enjoyed the Chatsworths I owned, great speakers and lovely looking. Shame the wife didn't agree. Sure they'll be cracking once you've given them some love.

 

[divedeepdog]

I prefer them visually to the Eatons I've got, bigger speakers, but same footprint, and of course they sound better.
I've ordered this:
http://rover.ebay.com/rover/1/710-5...0001&campid=5338728743&icep_item=272314895189

I'll assess when it arrives how transparent it is. I had cork baffle and removable grill in mind, but Frank's comments elsewhere has got me wondering again.

If my woodyard is open I'll redo the baffles, 1 fabric is intact and you never know another may come up on ebay. I suspect removing the fabric will destroy it anyway.