When you are at fine tuning stage try mechanical damping, works for most boxes, but more so with bass reflex imo.
Basically with speakers in final position cut a length of wood (or metal rod etc), and position between centre of back of speaker and adjacent wall.
Mileage varies, but definitely one to try. Also there is a school of thought to use the bear minimum of damping with a br enclosure.
Basically with speakers in final position cut a length of wood (or metal rod etc), and position between centre of back of speaker and adjacent wall.
Mileage varies, but definitely one to try. Also there is a school of thought to use the bear minimum of damping with a br enclosure.
Hi, guys.
Looking at Sreten's drawing, I wonder if that much bracing is needed in a small cabinet like mine. It's going to be around 36.5 liters, bracing not included (approx. 25x30x50cm). I will add some top-bottom and front-back bracing, though. It will need some re-calculation.
Do I need to screw all the braces to the cabinet, or is just glueing sufficient? I can imagine glue stretching somewhat (and maybe breaking?), while screws are much more firm. Besides that, It would be impossible to screw all braces into the baffle, since that is designed to be able to come off, in case it needs to.
Thanks.
Looking at Sreten's drawing, I wonder if that much bracing is needed in a small cabinet like mine. It's going to be around 36.5 liters, bracing not included (approx. 25x30x50cm). I will add some top-bottom and front-back bracing, though. It will need some re-calculation.
Do I need to screw all the braces to the cabinet, or is just glueing sufficient? I can imagine glue stretching somewhat (and maybe breaking?), while screws are much more firm. Besides that, It would be impossible to screw all braces into the baffle, since that is designed to be able to come off, in case it needs to.
Thanks.
Hi,
a partition running from top to bottom and side to side glued and screwed into place may suffice for a cabinet of this size. The partition should have two very large holes cut in it to form a spectacle shape. If the partition is placed off centre and possibly off vertical it will result in all the unsuppoted panels being of different shapes and sizes giving rise to a very wide range of much smaller panel resonances.
Adding a little bit of damping could well result in a very dead cabinet.
Arrange for one of your spectacle openings to be directly behind the driver/s to allow terminal connections etc.
Using the above method will result in the largest unsupported panels being the back and front. Consider using very thick material for these, try 30 to 40 mm thick.
The external size is now very much bigger than your 36litres, possibly over 50litres.
a partition running from top to bottom and side to side glued and screwed into place may suffice for a cabinet of this size. The partition should have two very large holes cut in it to form a spectacle shape. If the partition is placed off centre and possibly off vertical it will result in all the unsuppoted panels being of different shapes and sizes giving rise to a very wide range of much smaller panel resonances.
Adding a little bit of damping could well result in a very dead cabinet.
Arrange for one of your spectacle openings to be directly behind the driver/s to allow terminal connections etc.
Using the above method will result in the largest unsupported panels being the back and front. Consider using very thick material for these, try 30 to 40 mm thick.
The external size is now very much bigger than your 36litres, possibly over 50litres.
Hi,
Glueing the braces will be fine, adding screws is pointless.
The number "8" frame described by AT is good for thin, tall,
and deep cabinet designs, not so good for bluffer shaped
boxes. If the box is very tall 3 holes are better than 2.
IMO the boxes are quite large and the bracing is needed.
Variations of the bracing is possible. Use an 8 frame offset
forward + the original back brace @ 0.4 x hieght and join
them. Use 2" for the front baffle braces and join these to
the baffle not the cabinet, or other variations.
Massively thick baffles and backs reduce the actual volume to
percieved volume too much IMO, bracing is much better IMO.
🙂/sreten.
Glueing the braces will be fine, adding screws is pointless.
The number "8" frame described by AT is good for thin, tall,
and deep cabinet designs, not so good for bluffer shaped
boxes. If the box is very tall 3 holes are better than 2.
IMO the boxes are quite large and the bracing is needed.
Variations of the bracing is possible. Use an 8 frame offset
forward + the original back brace @ 0.4 x hieght and join
them. Use 2" for the front baffle braces and join these to
the baffle not the cabinet, or other variations.
Massively thick baffles and backs reduce the actual volume to
percieved volume too much IMO, bracing is much better IMO.
🙂/sreten.
Hi, people.
Due to circumstances and other things, I've still not started rebuilding the Tannoys... But I still have the designs and plans for an improvement on them.
Since my last post, I've moved twice and now I'm in the posession of a pretty nice listening environment, with a reasonably flat frequency response at my listening position. Last night I gave the Stratfords another testdrive, and despite their apalling cabinet state, they sound truly amazing, somewhat reminiscent of some high-end studio monitors I've worked with over the last couple of years. Not so much low end (rolls of at around 55Hz, true to spec, in contrast to the 40Hz I stated earlier in a poor room), not so much low end 'punch', but loads of detail and clarity. Very, very nice. There is however a slight cabinet resonance at around 200Hz - the lower vocal range and some upper bass suffers in terms of definition. I think, if I am to build a new cabinet, this is one major issue to tackle. Eventually, a decent sealed subwoofer per channel to support them, and I will be a happy audiophile 🙂
I've re-read this topic and there is a lot to learn from it. Inspired by PA speakers, the Dynaudio "Focus" line of loudspeakers and some KEF and Tannoy models, I thought it might be a good idea to make the cabinets slightly trapezoid, though that is more complex to cut and build. But I think it will do a lot to tame cabinet resonances. Any thoughts on that? I "just" need to find a way to calculate the volume of a trapezoid...
Does anyone know where I can find some info on flared ports and how they differ in calculating dimensions as opposed to straight ports?
Thanks!
Due to circumstances and other things, I've still not started rebuilding the Tannoys... But I still have the designs and plans for an improvement on them.
Since my last post, I've moved twice and now I'm in the posession of a pretty nice listening environment, with a reasonably flat frequency response at my listening position. Last night I gave the Stratfords another testdrive, and despite their apalling cabinet state, they sound truly amazing, somewhat reminiscent of some high-end studio monitors I've worked with over the last couple of years. Not so much low end (rolls of at around 55Hz, true to spec, in contrast to the 40Hz I stated earlier in a poor room), not so much low end 'punch', but loads of detail and clarity. Very, very nice. There is however a slight cabinet resonance at around 200Hz - the lower vocal range and some upper bass suffers in terms of definition. I think, if I am to build a new cabinet, this is one major issue to tackle. Eventually, a decent sealed subwoofer per channel to support them, and I will be a happy audiophile 🙂
I've re-read this topic and there is a lot to learn from it. Inspired by PA speakers, the Dynaudio "Focus" line of loudspeakers and some KEF and Tannoy models, I thought it might be a good idea to make the cabinets slightly trapezoid, though that is more complex to cut and build. But I think it will do a lot to tame cabinet resonances. Any thoughts on that? I "just" need to find a way to calculate the volume of a trapezoid...
Does anyone know where I can find some info on flared ports and how they differ in calculating dimensions as opposed to straight ports?
Thanks!
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