Don't tempt me! I would like to try a valve amp one day, Radfords seem to be well thought of when paired with Tannoys. I'm trying to stop messing with equipment and just listen to music but you guys make it hard for me to kick the habit!
Tannoy Lockwood Academy 2's. First listening impressions and advice sought.
- Thread starter Chas B
- Start date
Tony L
Administrator
Old-school Lockwoods are ‘aperiodic loading’, not ported, e.g. if you look at the pic of mine on the previous page you can make out a fairly thick sheet of felt running across a shelf between the top and bottom halves of the cabinet. As I understand it this means the driver has the freedom and lack of resistance of a large cabinet, but it isn’t designed to boost or hype-up bass response the way a conventional ported cab does. Think of it more as a damped vent. I don’t know how the current cabs are designed, but the bung may well be deliberate if they are continuing the vintage Lockwood loading concept.
These are the Academy 2's but you are right, I have seen pics online of another pair that don't have a port. I wonder if a bit of DIYing has gone on?
I had a listen late last night with the bungs removed, I could here some extra low bass but I don't think it was an improvement as such. The bungs will be going back in...
Thanks Cooky that's interesting. So after reading this I measured the cabinet dimensions myself, they are actually 76.5 x 51 x 36 so approximately 120l but I'm not allowing for the driver and bracing etc. I will have to open them up again and measure the ports.
I had a very enjoyable listening session last night with bungs reinstalled but if there is more to be had from these I am interested in persuing it.
So I've spent most of this evening re-reading various threads relating to the big Tannoys and cabinet designs. I came across the following info and wonder if it is applicable to my HPD315/Academy 2 cabs?
'Monitor Gold 12R in 120l cab - port 10cm diameter X 17.73 long.'
I need to check the port size but from memory it's nowhere near 10cm diameter!
'Monitor Gold 12R in 120l cab - port 10cm diameter X 17.73 long.'
I need to check the port size but from memory it's nowhere near 10cm diameter!
cooky1257
pfm Member
In terms of the response the Monitor Gold is fairly close but not the same as the HPD. That's a 28hz box tuning for a port clear of any enclosure boundaries.
But you have HPD's, that tuning produces an EBS shelf that's too deep, a 32 hz tuning is better in terms of curve, port air speed, and group delay ie a port 100 mm x 119 mm long clear of boundaries.
Having said that, 120L is as big as you need to go with a sealed box and they should already be giving you decent amounts of tight bass and seeing how they've been messed with ( ported)think it worth undoing the 4 nuts and having a look at those drivers, checking polarity etc for piece of mind if nowt else.
But you have HPD's, that tuning produces an EBS shelf that's too deep, a 32 hz tuning is better in terms of curve, port air speed, and group delay ie a port 100 mm x 119 mm long clear of boundaries.
Having said that, 120L is as big as you need to go with a sealed box and they should already be giving you decent amounts of tight bass and seeing how they've been messed with ( ported)think it worth undoing the 4 nuts and having a look at those drivers, checking polarity etc for piece of mind if nowt else.
That's good info, thanks. It's also a good reminder that I shouldn't assume, if polarity is wrong it would explain a lot re. the slightly disappointing bass. Am I right in thinking that this can be checked with a 1.5V battery somehow? Isn't there some weirdness with Tannoy drivers and the driver should move backwards when voltage is applied rather than forwards as you would expect?
cooky1257
pfm Member
It's in the K series studio monitors manual but I wouldn't worry, so long as they both move in the same direction they will be in phase with each other -plenty of pics online showing the wiring colours from xover to driver.
ToTo Man
the band not the dog
If the polarity was wrong in one speaker then you'd get stronger bass with one channel playing than with two. Easy to test this by playing a bass-heavy mono recording and unplugging one speaker from the amp (not while the music's playing of course or you could let out some magic smoke! 
).
).Under no circustances do I ever want to see the magic smoke!
This evening I checked the driver polarity with a 1.5V battery. Both drivers move backwards ie into the basket so all seems good there. Maybe I'm expecting too much? I thought I would get the sort of bass that you feel in your guts, I've used smaller speakers that do that...
Whilst in the cabinets again I checked the port dimensions too, they are 68mm internal diameter by 118mm long so rather small.
This evening I checked the driver polarity with a 1.5V battery. Both drivers move backwards ie into the basket so all seems good there. Maybe I'm expecting too much? I thought I would get the sort of bass that you feel in your guts, I've used smaller speakers that do that...
Whilst in the cabinets again I checked the port dimensions too, they are 68mm internal diameter by 118mm long so rather small.
cooky1257
pfm Member
Looks like they tuned the box to the driver Fs of around 23 hz, port air speed is way too high at 24m/s and the roll off/shelf is severe. if you added second port of the same dimensions then you'd shift cab tuning to 33hz and sort the port chuff and bass response out.Under no circustances do I ever want to see the magic smoke!
This evening I checked the driver polarity with a 1.5V battery. Both drivers move backwards ie into the basket so all seems good there. Maybe I'm expecting too much? I thought I would get the sort of bass that you feel in your guts, I've used smaller speakers that do that...
Whilst in the cabinets again I checked the port dimensions too, they are 68mm internal diameter by 118mm long so rather small.
Graphs to follow.
cooky1257
pfm Member
If you compare the freq response graphs you can see where you may be missing a fair bit of bottom end, compare 1&2 with Graph 3, based on experience with Tannoy Balmorals (120L ported@32 hz) is where I've been there done that, just fab highly recommended. FWIW though I'd only recommend you changing the Academy2 because someone has already modified them and they are no longer as original so you aren't devaluing them further - you can always block 2 ports just as easily as 1!
Thanks again! I'll start looking for some suitable port tubes. With ports is it simply a matter of correct volume eg would one port equivalent to the two smaller ports work in the same way?
Yes it's a shame they've been modified but I might as well make the most of them now. Also very easy to remake a standard front panel if I needed to but hopefully they are keepers... where have I heard that before!
Yes it's a shame they've been modified but I might as well make the most of them now. Also very easy to remake a standard front panel if I needed to but hopefully they are keepers... where have I heard that before!
cooky1257
pfm Member
Modifying an existing hole to 102mm dia is a bit of a pain whereas cutting another @ 72mm or so (to allow for tube walls) with a 118 mm long tube seems easier to me.
If you do decide to cut another baffle then you can certainly go for the 100mm dia x 155mm port, make sure it's at least 150 mm clear of any cab walls and think about front mounting/rebating the driver.
If you do decide to cut another baffle then you can certainly go for the 100mm dia x 155mm port, make sure it's at least 150 mm clear of any cab walls and think about front mounting/rebating the driver.
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