The wife is giving me the whole day to work on audio projects. Subject number one for today is a pair of Tannoy Royal Monitors (15' HPDs). They need new surrounds and the HF driver needs adjustment.
The HPD's are common but you don't see many with the blue magnet cover.
The HPD's are common but you don't see many with the blue magnet cover.
Attachments
Can we look forward to more pics as you progress? 
I think the Royals were specific for the canadian market, the blue magnet cover is the only difference.
Since they need new surounds you could recone them with Monitor Gold cones which makes them identical to Golds with the exception of vastly increased power handling due to more modern glue and formers. If I remember correctly they will take 350wrms after a recone.
Since they need new surounds you could recone them with Monitor Gold cones which makes them identical to Golds with the exception of vastly increased power handling due to more modern glue and formers. If I remember correctly they will take 350wrms after a recone.
I've adjusted the HF driver. Maybe it is me, but they seem a bit peaked in the high-mids. Apparently I've got dog like hearing because I'm not getting the very high frequencies I was hoping for. Perhaps this calls for a super tweeter? Otherwise adjustment wasn't as hard as I expected. Now for replacing the surrounds.
I believe these were purchased second-hand from a Canadian. Furthermore they are mounted in large infinite baffle cabinents. I'm tempted to leave out the crossover to make an impromptu rear firing port, but the bass is already pretty wild on these guys.
I don't like new phones. The one on my desk is an old Kellogg ITT I think. In the kitchen I've got a nice Western Electric wall mount that is the same era as the desk phone. They outlasted their owners and will probably outlast me too.
I believe these were purchased second-hand from a Canadian. Furthermore they are mounted in large infinite baffle cabinents. I'm tempted to leave out the crossover to make an impromptu rear firing port, but the bass is already pretty wild on these guys.
I don't like new phones. The one on my desk is an old Kellogg ITT I think. In the kitchen I've got a nice Western Electric wall mount that is the same era as the desk phone. They outlasted their owners and will probably outlast me too.
Attachments
Last edited:
From the speakerbits instructions (very detailed) I have to remove the spider to remove the cone. Problem is the screws for the spider are covered by the magnet. So I removed one magnet. Take note that these are very powerful magnets. Keep anything remotely magnetic away. Otherwise some significant effort may be needed to separate things.
I apparently made a not so great decision. The screws are a wimpy aluminum or zinc and I sheered one off. I think they are supposed to be removed from the nut side instead. I think it is salvageable so I'll keep moving.
I apparently made a not so great decision. The screws are a wimpy aluminum or zinc and I sheered one off. I think they are supposed to be removed from the nut side instead. I think it is salvageable so I'll keep moving.
Attachments
Member
Joined 2003
The enamel is a bit cooked there. If you connect a multimeter you'll know if it's shorted or not, that is assuming you haven't tested the drivers to see if they work.
If the measurements check out, it's probably still okay, however the extreme high voltage resistance that the enamel once carried is likely lost, however that shouldn't be much of a problem for a loudspeaker. If you run your fingernail along the voicecoil and the enamel flakes off, then you're in trouble.
I would also be worried if the magnets in these are AlNiCo, as they loose their charge if the speaker is horribly overdriven.
If the measurements check out, it's probably still okay, however the extreme high voltage resistance that the enamel once carried is likely lost, however that shouldn't be much of a problem for a loudspeaker. If you run your fingernail along the voicecoil and the enamel flakes off, then you're in trouble.
I would also be worried if the magnets in these are AlNiCo, as they loose their charge if the speaker is horribly overdriven.
I have a mess of photos to upload when I get a chance, but I completed the rebuild yesterday. One speaker's HF driver is a bit off and I need to readjust again. The other speaker is just right. Wow. Very nice. Now I understand why these are desire able speakers. The improvement after the rebuild is significant. I'd guess you could complete the job on two speakers in about 16 hrs of effort unless you do this sort of thing everyday.
One thing I tried was to remove the crossover from the cabinent and place it inside. As a result the opening made a good sized rear firing port on the cabinent. The bass was so heavy that I stuffed one of the kids teddy bears in the hole to get it under control.
There's no replacement for displacement. 15 inch speakers are really something.
There's no replacement for displacement. 15 inch speakers are really something.
All Tannoy xovers I've ever looked at (Gold, HPD, K-series) use a modified 2nd order lo pass and a 1st order hi pass plus a notch filter.
To replicate that (more or less) with an analog active xover you will need two bands of parametric eq for each channel on the tweeter.
One band to remove the honkiness which is the result of some loading issues due to the pepperpot compression driver and one band to achieve the necessary boost that these tweeter require just like all other constant directivity horns.
To replicate that (more or less) with an analog active xover you will need two bands of parametric eq for each channel on the tweeter.
One band to remove the honkiness which is the result of some loading issues due to the pepperpot compression driver and one band to achieve the necessary boost that these tweeter require just like all other constant directivity horns.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.