GM,
They believe they can make a new connection to the voice coil to avoid the need to change the coil, cone, surround & spider assembly. If it turns out they can't, I'll have to weigh having both speakers reworked at the same time. New ones are $128 each& I haven't located any used Hemptone FR8 speakers.
I gather that over driving them causes the problem. I don't know if that's the case with these used modified speakers.
I'm keeping my fingers crossed.
Frank
They believe they can make a new connection to the voice coil to avoid the need to change the coil, cone, surround & spider assembly. If it turns out they can't, I'll have to weigh having both speakers reworked at the same time. New ones are $128 each& I haven't located any used Hemptone FR8 speakers.
I gather that over driving them causes the problem. I don't know if that's the case with these used modified speakers.
I'm keeping my fingers crossed.
Frank
Wharfedale Super 12 CS/AL MLTL design musings
Sorry, don’t have time to write any tutorials, but there’s MJK’s collected works as well as Bob Brines and some others as well as all the various postings by me, Scott[moose], bjorno, et al.
With no experience with this driver and not even sure I’ve ever auditioned one [the big sand filled construction corner reflex with the mid/HF ‘tophat’ is the only one I recall ATM], not sure why at least of these didn’t perform well unless you mean bass ‘shy’.
Regardless, the little info I have implies a very low Qt motor with a high Vas compliance, so either a high output impedance amp or at least a PP one with variable DF [bass boost tone control] is required, hence a large cab, especially if not in a corner.
If very low PP or SS driven, then it will probably mean up to 15+ dB of BSC with a HF by-pass cap to flatten it out from ~30 – 12 kHz and require a capped off super tweeter up around 36 kHz if you want some top end ‘air’ for those that can still perceive it.
Anyway, in your loft, the ~10.4 ft^3 cab tuned to ~30 Hz is my SWAG and if nothing else should give an adequate amount of tuning flexibility; otherwise it’ll take measured driver and room acoustic specs to pare it down as much as practical to get the max practical efficiency to ~30 Hz.
Assuming a ~38” seated ear height:
L = 60”
CSA = 300”^2 [~17.32” square or ~22” x ~13.63” if rectangular]
Zdriver = 24.43”
Zport = near/at the bottom
Dport = 6”
Lport = ~0.75” as a 1st approximation
All dims i.d. and approximate. Line the top, one side and back wall down around halfway with 1” acoustic fiberglass or similar insulation initially. If polyfil stuffing, then ~10 oz loosely filling the same area.
GM
Sorry, don’t have time to write any tutorials, but there’s MJK’s collected works as well as Bob Brines and some others as well as all the various postings by me, Scott[moose], bjorno, et al.
With no experience with this driver and not even sure I’ve ever auditioned one [the big sand filled construction corner reflex with the mid/HF ‘tophat’ is the only one I recall ATM], not sure why at least of these didn’t perform well unless you mean bass ‘shy’.
Regardless, the little info I have implies a very low Qt motor with a high Vas compliance, so either a high output impedance amp or at least a PP one with variable DF [bass boost tone control] is required, hence a large cab, especially if not in a corner.
If very low PP or SS driven, then it will probably mean up to 15+ dB of BSC with a HF by-pass cap to flatten it out from ~30 – 12 kHz and require a capped off super tweeter up around 36 kHz if you want some top end ‘air’ for those that can still perceive it.
Anyway, in your loft, the ~10.4 ft^3 cab tuned to ~30 Hz is my SWAG and if nothing else should give an adequate amount of tuning flexibility; otherwise it’ll take measured driver and room acoustic specs to pare it down as much as practical to get the max practical efficiency to ~30 Hz.
Assuming a ~38” seated ear height:
L = 60”
CSA = 300”^2 [~17.32” square or ~22” x ~13.63” if rectangular]
Zdriver = 24.43”
Zport = near/at the bottom
Dport = 6”
Lport = ~0.75” as a 1st approximation
All dims i.d. and approximate. Line the top, one side and back wall down around halfway with 1” acoustic fiberglass or similar insulation initially. If polyfil stuffing, then ~10 oz loosely filling the same area.
GM
- Status
- Not open for further replies.