Hi everyone I’m a very novice diy speaker builder and having some trouble trying to build some speakers with tannoy drivers.
I did a bit of research and decided on using tannoy 2062 drivers (from the tannoy i8 pa speaker model)
I read that they are very similar to the tannoy sandringham model that goes down to 39hz and also that the sound quality is very good with the classic tannoy sound so thought...brilliant! I’ll try to make something similar.
I’ve got them in 47litre ported enclosure of a floor stander type.
Problem is I’m finding for one, by putting a sine wave test tone through them the frequency drops very quickly below 60hz, and I have to turn the mid down quite a bit to get the bass to come through. Also I can’t “feel” the bass that much and the bass I can feel is quite airy, if that makes sense.
It’s a a 47 litre enclosure with two 5cm diameter x 2.5cm length ports.
This is what I got from a speaker calculator online.
I do have the specs for them if anyone is able to help.
Quite gutted as I’ve spent quite a bit of time on them but just don’t seem to be getting very far with it.
I did a bit of research and decided on using tannoy 2062 drivers (from the tannoy i8 pa speaker model)
I read that they are very similar to the tannoy sandringham model that goes down to 39hz and also that the sound quality is very good with the classic tannoy sound so thought...brilliant! I’ll try to make something similar.
I’ve got them in 47litre ported enclosure of a floor stander type.
Problem is I’m finding for one, by putting a sine wave test tone through them the frequency drops very quickly below 60hz, and I have to turn the mid down quite a bit to get the bass to come through. Also I can’t “feel” the bass that much and the bass I can feel is quite airy, if that makes sense.
It’s a a 47 litre enclosure with two 5cm diameter x 2.5cm length ports.
This is what I got from a speaker calculator online.
I do have the specs for them if anyone is able to help.
Quite gutted as I’ve spent quite a bit of time on them but just don’t seem to be getting very far with it.
Have you measured the T/S parameters, or did you pull them from a website?
It's entirely possible that your drivers differ significantly from their original specs.
Next up, a floor-standing ported box will likely have an aspect ratio that lends some 1/4-wave action. ie, it's not just acting as a Helmholtz Resonator any more, despite the calculator's assumptions.
Your room will also screw up the sound in a wide variety of ways - I've measured 15dB differences between simulation and reality.
There are, however, some things we can do to get you up and running. It'd be useful to have a drawing (or pictures) of the speaker as-built, with dimensions included.
One test you can do is to set off at 20Hz, turn it up so the cone's moving a little, and slowly increase the test frequency. When the cone stops moving, you've found the tuning frequency.
Putting the numbers through Hornresp, it looks like you've got a ~60Hz tuning frequency with ports of those dimensions (assuming a ported box - see my note earlier). If you block one of the ports, the tuning drops to the mid-40s.
Did you simulate with one port, and then install two? If so, no worries, just block one of them from the inside. Or, lengthen both. The latter would be preferable for high-power use.
With regards to the overall tonal balance, what's your crossover circuit?
... and what's your room positioning?
It's entirely possible that the crossover supplied by Tannoy is intended for near-wall use, and if your speakers are further from the wall, they'll need some baffle-step compensation - BSC.
If you've rolled your own crossover, that could be an issue. Crossover design is non-trivial. I use a measurement mic to capture the driver curves, and then import those into a simulator and go through a lot of different circuits before I find something worth building.
Even then, it might not always work out - the simulator doesn't include harmonic distortion etc.
Lots to go on there. Give us as much info as you can - you literally can't tell us too much. Some people get as far into it as recommending different brands of capacitors - we're not there yet (and I suspect I never will be).
Chris
It's entirely possible that your drivers differ significantly from their original specs.
Next up, a floor-standing ported box will likely have an aspect ratio that lends some 1/4-wave action. ie, it's not just acting as a Helmholtz Resonator any more, despite the calculator's assumptions.
Your room will also screw up the sound in a wide variety of ways - I've measured 15dB differences between simulation and reality.
There are, however, some things we can do to get you up and running. It'd be useful to have a drawing (or pictures) of the speaker as-built, with dimensions included.
One test you can do is to set off at 20Hz, turn it up so the cone's moving a little, and slowly increase the test frequency. When the cone stops moving, you've found the tuning frequency.
Putting the numbers through Hornresp, it looks like you've got a ~60Hz tuning frequency with ports of those dimensions (assuming a ported box - see my note earlier). If you block one of the ports, the tuning drops to the mid-40s.
Did you simulate with one port, and then install two? If so, no worries, just block one of them from the inside. Or, lengthen both. The latter would be preferable for high-power use.
With regards to the overall tonal balance, what's your crossover circuit?
... and what's your room positioning?
It's entirely possible that the crossover supplied by Tannoy is intended for near-wall use, and if your speakers are further from the wall, they'll need some baffle-step compensation - BSC.
If you've rolled your own crossover, that could be an issue. Crossover design is non-trivial. I use a measurement mic to capture the driver curves, and then import those into a simulator and go through a lot of different circuits before I find something worth building.
Even then, it might not always work out - the simulator doesn't include harmonic distortion etc.
Lots to go on there. Give us as much info as you can - you literally can't tell us too much. Some people get as far into it as recommending different brands of capacitors - we're not there yet (and I suspect I never will be).
Chris
I couldn’t find the specs anywhere online, luckily enough a guy that’s also building a pair done some measurements and sent them to me. (He’s building a 100L enclosure which would be way to big for my living room so my build will have to be different)
What he sent me is...
D 175mm
Re 4.762 ohms
Fs 94.17 hz
Zm 30.94 ohms
Bl 6.731 n/a
Qms 3.896
Qes 0.7087
Qts 0.5996
Vas 20.37 L
L10k 0.3383 mh
N0 2.289 %
Dpspl 95.7 1w/1m
Ms 11.39 grams
Cms 0.251 mm/n
Dimensions of the cab is...
W 28cm
H 79cm
D 30cm
19mm chipboard
Driver centred 10cm down from top
First port 10 cm below driver then second 8cm below that.
Your tip on finding the tuning frequency is good, I’ll try this.
I did try with one port but they didn’t seem to go very low listening to music, with two (but it worked out to be very short ports) I seemed to have lower bass with music.
I didn’t try a frequency sweep with one port. Only the two. Then realised the bass drops very quick after 60hz.
Haven’t tried blocking one and doing a sweep yet.
Crossover is the original that came out of the i8 speaker.
I did ask on another forum about upgrading the xover but was told the xover is good.
I have learned that these drivers are better used as mids with a sub but if I can...I’d like to just have these.
Thanks for the reply.
What he sent me is...
D 175mm
Re 4.762 ohms
Fs 94.17 hz
Zm 30.94 ohms
Bl 6.731 n/a
Qms 3.896
Qes 0.7087
Qts 0.5996
Vas 20.37 L
L10k 0.3383 mh
N0 2.289 %
Dpspl 95.7 1w/1m
Ms 11.39 grams
Cms 0.251 mm/n
Dimensions of the cab is...
W 28cm
H 79cm
D 30cm
19mm chipboard
Driver centred 10cm down from top
First port 10 cm below driver then second 8cm below that.
Your tip on finding the tuning frequency is good, I’ll try this.
I did try with one port but they didn’t seem to go very low listening to music, with two (but it worked out to be very short ports) I seemed to have lower bass with music.
I didn’t try a frequency sweep with one port. Only the two. Then realised the bass drops very quick after 60hz.
Haven’t tried blocking one and doing a sweep yet.
Crossover is the original that came out of the i8 speaker.
I did ask on another forum about upgrading the xover but was told the xover is good.
I have learned that these drivers are better used as mids with a sub but if I can...I’d like to just have these.
Thanks for the reply.
Assuming the data provided and the box / vent dimensions provided, the speaker is tuned to about 68Hz, and like other vented boxes will unload 24dB/octave below that (i.e. output below about 60Hz will fall away quite steeply and the driver excursion will rapidly increase).
It's basically given you a relatively flat alignment to as low as the driver is theoretically able to manage -about 0.707x Fs. This Tannoy unit has a high resonant frequency; the middling Q allows it to be used lower, but that only goes so far, and about 60Hz is actually quite respectable for a unit with an Fs of 94Hz in a conventional Helmholtz type box. You can tune it lower by increasing the vent length (or blocking one of the vents) but you'll lose gain (output) as a result, so it may actually end up having less in the way of usable bass response than it did before. It's possible to squeeze more LF out of it using a QW type enclosure (the current dimensions + vent locations aren't really such that will generate any usable eigenmodes that will help in this regard), but it would need a significantly larger enclosure in terms of height & volume. Sorry, can't beat the laws if physics I'm afraid.
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If this is the correct manual for the Drivers used, it does seem to suggest wall mounted or close to with the Tannoy OEM brackets.
https://warehousesound.com/r/tannoyI8manual.pdf
Is the Sandringham cabinet larger than your build?
The sandringham is a floorstander that’s only 39litre but claims to go down to 39hz also.
To be fair this driver is said to be very similar, not the exact same. Also the sandringham isn’t a basic ported enclosure. I think it’s an onken petite type, not sure if this can make a difference?
I don’t mind losing gain as they can go very loud as it is.
To be fair this driver is said to be very similar, not the exact same. Also the sandringham isn’t a basic ported enclosure. I think it’s an onken petite type, not sure if this can make a difference?
I don’t mind losing gain as they can go very loud as it is.
Yeah, I'm afraid you're probably getting all you'll get out of some 8" PA speakers with an Fs in the mid-90s. They'll be optimised for >100Hz, and in the intended application subwoofers would be mandatory if any bass is required. You could manage singer + guitar with those, but that's about it.
In terms of where to go next, I guess that's up to you. I can make a few suggestions, though:
- Put them in smallish sealed boxes, and add a subwoofer
- Build bigger cabinets that allow more LF reinforcement
- Swap out the drivers for something more suitable.
The first one would be where I'd go. You'd be able to use a fairly small sealed box and possibly hide the subwoofer, leading to a visually compact setup with more low-frequency potential than the Tannoy drivers alone could manage.
The second option would be a simple solution (2-channel HiFi amp, etc etc), but doesn't seem like a viable option given the mention of space constraints.
The third option would take some digging around to find something more suitable, but would probably allow you to use your existing cabinets (possibly with modifications) and achieve satisfying performance.
It's worth keeping Hoffman's Iron Law in mind: small size, low bass, efficient - pick any two. The Tannoy drivers are fairly small, and very efficient, so low bass has suffered. A typical HiFi driver might have 10dB less sensitivity, but would probably have much more low-frequency extension, which is what you appear to be looking for.
Chris
In terms of where to go next, I guess that's up to you. I can make a few suggestions, though:
- Put them in smallish sealed boxes, and add a subwoofer
- Build bigger cabinets that allow more LF reinforcement
- Swap out the drivers for something more suitable.
The first one would be where I'd go. You'd be able to use a fairly small sealed box and possibly hide the subwoofer, leading to a visually compact setup with more low-frequency potential than the Tannoy drivers alone could manage.
The second option would be a simple solution (2-channel HiFi amp, etc etc), but doesn't seem like a viable option given the mention of space constraints.
The third option would take some digging around to find something more suitable, but would probably allow you to use your existing cabinets (possibly with modifications) and achieve satisfying performance.
It's worth keeping Hoffman's Iron Law in mind: small size, low bass, efficient - pick any two. The Tannoy drivers are fairly small, and very efficient, so low bass has suffered. A typical HiFi driver might have 10dB less sensitivity, but would probably have much more low-frequency extension, which is what you appear to be looking for.
Chris
Thanks chris, I think I’m going to have to sell the drivers on. The enclosures arnt pretty, just knocked up as testing cabs. The dream is to have just one set of floor standers that I’ve made that can push those lower frequency’s.
I do have some 10” tannoy monitor golds but they’re locked away till we get a bigger place as they’re a bit too wide so ideally did want the same tannoy sound, just in a slightly smaller/thinner package.
I do have some 10” tannoy monitor golds but they’re locked away till we get a bigger place as they’re a bit too wide so ideally did want the same tannoy sound, just in a slightly smaller/thinner package.
Just a thought on the subwoofer option...
If the drivers original tannoy spec is to be in a 16.6L cab ported giving a range of 85hz-22khz, could I add a sub to the enclosure concealed inside in a separate chamber?
That way I could have all the low end I’d like but with the clean look of one driver and still have the “tannoy sound” going on.
On a quick search there is a band pass box design where the subwoofer is concealed
If the drivers original tannoy spec is to be in a 16.6L cab ported giving a range of 85hz-22khz, could I add a sub to the enclosure concealed inside in a separate chamber?
That way I could have all the low end I’d like but with the clean look of one driver and still have the “tannoy sound” going on.
On a quick search there is a band pass box design where the subwoofer is concealed
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I was looking to do something similar with the drivers out of T12.
I am pretty sure that the Pro versions of the drivers exchange less bass response for more efficiency (ceratinly the one i was looking at). The driver you have comes out of a box that claims F(-3) of 85 Hz.
As well i have found that the hifi offerings from Tannoy try to get way lower bass out of the drivers than i would feel comfortable with. AFAIC for deep bass w a Tannoy you need a helper woofer.
I strongly suspect that your driver is quite distinct from those used in Sandringham.
dave
What kit did he use to get the parameters? The stuff us guys use at home does not collapse the T/S vectors in the same place as the typical factory software and i have found that the factory numbers are more reliable at getting a box right on 1st crack.
The numbers you have are certainly better than nothing as a starting point.
dace
Yes Hart Audio do the 12" version bass assisted!
An externally hosted image should be here but it was not working when we last tested it.
Sims based on these numbers. I could not (quickly) find any vented box i was happy with, the shown sim would require a long high ratio slot vent to tame the peak near roll-off. Then an estiated F(-10) in the low 50s.
dave
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