'Castle' Microtowers with CHP-70
I've built some 'Castle' Microtowers using nominal 18mm ply (measures 17mm) to the same internal dimensions as the plan, including holey braces
Drivers are CHP-70.
I had some 2.5 inch internal dia. pipe, and at the moment I'm using a 2.5 inch length of that for a port. The port output rises a little around 50Hz and drops off rapidly below about 40Hz.
I would welcome any advice on how to go about tuning the port for these drivers.
I'm listening at low levels for now as they begin to break in, so I'll report on the sound in due course.
I've built some 'Castle' Microtowers using nominal 18mm ply (measures 17mm) to the same internal dimensions as the plan, including holey braces
Drivers are CHP-70.
I had some 2.5 inch internal dia. pipe, and at the moment I'm using a 2.5 inch length of that for a port. The port output rises a little around 50Hz and drops off rapidly below about 40Hz.
I would welcome any advice on how to go about tuning the port for these drivers.
I'm listening at low levels for now as they begin to break in, so I'll report on the sound in due course.
I've built some 'Castle' Microtowers using nominal 18mm ply (measures 17mm) to the same internal dimensions as the plan, including holey braces
Drivers are CHP-70.
I had some 2.5 inch internal dia. pipe, and at the moment I'm using a 2.5 inch length of that for a port. The port output rises a little around 50Hz and drops off rapidly below about 40Hz.
I would welcome any advice on how to go about tuning the port for these drivers.
I'm listening at low levels for now as they begin to break in, so I'll report on the sound in due course.
Hi John
Ah you built them
Do you have some pictures?
Hi John
Ah you built them
Do you have some pictures?
No pics yet, Richard - they are just the bare plywood and they will stay that way until I have finished experimenting with the damping and port tuning.
John
In my quest for prefecshun, and since the plans don't give recommended port dimensions for the CHP-70, I'm hoping that someone can advise me how best to go about tuning the port?
I don't have sophisticated software, just a sound level meter, multimeter, and the means for playing tones of different frequencies.
In my quest for prefecshun, and since the plans don't give recommended port dimensions for the CHP-70, I'm hoping that someone can advise me how best to go about tuning the port?
PM Dave or Scott. Pretty sure the boxes were modeled as TL's. Either way, you'll have to go with a longer port to drop Fb?
jeff
Indeed, and I have plenty of 2.5 in. pipe so it's easy enough to try out different lengths.
I've just seen, btw, that the CHP-70 is back on offer at Blue Planet Acoustic - 23 Euros each, and free shipping in the EU if you spend over 60 Euros.
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If you haven't already PM'd Dave, I've forwarded your query to him. IIRC, when I built the two versions of the towers, the ports for EL70 were 3" ID, while for CHR70 the ID was 2". I'm not sure if Dave rationalized the tuning for round ports of other ID, rectangular slots, or other drivers. of course that's just simple math
.
Well I'm listening to my 'Castle' microTowers with CHP-70s. They give a good open, detailed and spacious sound, and on most jazz they are pretty satisfactory. But on a lot of classical they sound thin and bright - violins in particular can sound quite steely.
They have had probably less than 30 hours fairly gentle playing so perhaps it's too soon to judge? Presumably adjusting the damping won't reduce the brightness? Should I run them in for longer before I think about compensation networks?
They have had probably less than 30 hours fairly gentle playing so perhaps it's too soon to judge? Presumably adjusting the damping won't reduce the brightness? Should I run them in for longer before I think about compensation networks?
Hi Jooners,
Could I ask what amp and source are you using with the CHP's? Silver or copper cables?
Thanks
Mark.
(CHP's need 200 hours of gentle running in)
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