You need to add in half the surround and subtract the phase plugs. Unless you ar eusing Sd to calculate Vas when measuring the T/S it does not play a role.
dave
8 inch driver with 1 mm Xmax in 150L box is really a waste of material, space, and time. It is like putting car engine to an aircraft carrier. Maybe it would be better to get better drivers.
I think you can get reasonable performance in 40L sealed box. It won't get much below 100Hz, but this driver is limited by Xmax below 200Hz anyway.
Last edited:
Mmd = Mms - (8/3) * density of air * piston radius^3 (Mmd Vs Mms)
You can't calculate Le. You could measure it, but it is not needed for enclosure simulation.
Last edited:
The bad news is these speakers are not suited to Karlson speakers. The large Vas and limited Xmax mean you cannot get to the lower freq. However the Karlsonator is definitely possible because it inherently reduces cone motion. Unfortunately i am not as creative as X so I cannot help you there. You will need X's help to simulate this in a karlsonator
if his suspension is like my stamped frame/ferrite AN8 - then Vas may not be very high 
- but Qt would rise too. I've used a UCX22 12" with Qt ~1.1 and Fs ~110Hz in K12 - no boom - no bass - nice mids - cone was basically locked from suspension aging. Same for a Lafayette SK-58 coax. Some old speakers seem to last forever with regards to staying near new Fs. My AN8 stiffened in a matter of a few years - perhaps its reversible with use and turpentine on the black goop
- but Qt would rise too. I've used a UCX22 12" with Qt ~1.1 and Fs ~110Hz in K12 - no boom - no bass - nice mids - cone was basically locked from suspension aging. Same for a Lafayette SK-58 coax. Some old speakers seem to last forever with regards to staying near new Fs. My AN8 stiffened in a matter of a few years - perhaps its reversible with use and turpentine on the black goop
Thanx.
I can't speak to that, but the olderstamped basket Super 8s i treated had measured T/S so different that they looked like different drivers and i was not all that impressed with their sonics.
dave
Hi guys,
Firstly, I really appreciate everyone chiming in with thoughts and ideas, it's helping me out a lot!
I decided to measure the results of stuffing and EQing to show you all in case you are interested (for science!).
Box capacity: ~55L, port hole tuned to 60Hz
Here is 1/12 smoothed curves before applying any stuffing:
Next is ~250g of stuffing in each box:
Next is stuffed and port hole blocked with thick foam:
So, what's interesting is without any stuffing, the bass is not terrible, and the treble is slightly muted.
After stuffing, the treble improves, and the bass gets weaker, even more so when port hole is stuffed as well.
After applying several EQ presets (19 entries), I have a much even curve:
What do you guys think? Is the treble region what most would consider "ragged"? Is this a limitation of full range drivers with whizzer cones?
The other thing that is interesting is these drivers are very weak in the 200-300Hz range, which is so essential to "full" sounding music. With my presets I am losing 9db to push those frequencies up (by 9db).
Firstly, I really appreciate everyone chiming in with thoughts and ideas, it's helping me out a lot!
I decided to measure the results of stuffing and EQing to show you all in case you are interested (for science!).
Box capacity: ~55L, port hole tuned to 60Hz
Here is 1/12 smoothed curves before applying any stuffing:
Next is ~250g of stuffing in each box:
Next is stuffed and port hole blocked with thick foam:
So, what's interesting is without any stuffing, the bass is not terrible, and the treble is slightly muted.
After stuffing, the treble improves, and the bass gets weaker, even more so when port hole is stuffed as well.
After applying several EQ presets (19 entries), I have a much even curve:
What do you guys think? Is the treble region what most would consider "ragged"? Is this a limitation of full range drivers with whizzer cones?
The other thing that is interesting is these drivers are very weak in the 200-300Hz range, which is so essential to "full" sounding music. With my presets I am losing 9db to push those frequencies up (by 9db).
Doesn't look bad (even un-stuffed).
Where all this measurements done in same position (mic and speakers)?
200-300Hz dip could be because of room (try different positions). Or maybe it is baffle step and then bump below 200Hz?
Stuffing probably helped treble, because port is close to speakers and leaked some high frequencies.
Where all this measurements done in same position (mic and speakers)?
200-300Hz dip could be because of room (try different positions). Or maybe it is baffle step and then bump below 200Hz?
Stuffing probably helped treble, because port is close to speakers and leaked some high frequencies.
Last edited:
My simulation showed 2.5 - 3 dB peak. Did you include stuffing?Questionable statement. Sim:
dave
You can add 200uF capacitor and it will be flat (ignoring room and baffle).
3 dB is not that much when you consider room effects and baffle step.
Simulation with baffle step (baffle dimensions are not exact):
Attachments
Last edited:
Greets!
'Sounds' like everything is as it should be, though a 200-400 Hz dip is usually an eigenmode, so is there a reflective surface [often the floor] around 22-23" from the driver's center?
GM
There is a new Nirvana FR, Classiz 8 Neodymium very sensitivity 97dB and 45-20kHz.
Impedance curve very nice, cone weight 12g.
http://www.commonsenseaudio.com/an8classicneospecs.jpg
Impedance curve very nice, cone weight 12g.
http://www.commonsenseaudio.com/an8classicneospecs.jpg
Not exactly a 'very nice' impedance curve either given the continual ripple exhibited, despite the 20ohm increments on the Y axis scale. Although in fairness, they're hardly alone in using variations on that one. Nobody would sell a widebander if they didn't, & it's nice to have another widebander without a whizzer.
What do you reckon Greg -about 7.25ohm output impedance or series R, sans a horn?
What do you reckon Greg -about 7.25ohm output impedance or series R, sans a horn?
Last edited:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.