Ok,
been a busy evening here. Here are some figures for the B&W drivers!
Qms 1.69
Qes 1.02
Qts 0.64
Do these make sense? I did it manually and at one point you have to do a back calculation* which did work out OK for me. Hope it makes sense to someone.
Fran
*(back calculation meant to match within 1hz and mine was 1.1Hz so I'm taking it that thats OK)
been a busy evening here. Here are some figures for the B&W drivers!
Qms 1.69
Qes 1.02
Qts 0.64
Do these make sense? I did it manually and at one point you have to do a back calculation* which did work out OK for me. Hope it makes sense to someone.
Fran
*(back calculation meant to match within 1hz and mine was 1.1Hz so I'm taking it that thats OK)
Ok so a revised list with more details:
Qms 1.69
Qes 1.02
Qts 0.64
Fs 45Hz
Vas 53.2litres
I did the calcs using the added weight method from the Rod Elliot site and it seemed to work out ok.
FWIW, there were 2 of these drivers in a sealed box of 50l (tweeter in same box).
Anything else I need to measure?
Fran
Qms 1.69
Qes 1.02
Qts 0.64
Fs 45Hz
Vas 53.2litres
I did the calcs using the added weight method from the Rod Elliot site and it seemed to work out ok.
FWIW, there were 2 of these drivers in a sealed box of 50l (tweeter in same box).
Anything else I need to measure?
Fran
Iain McNeill said:
The TLA for Passive Line Level crossOver
http://www.t-linespeakers.org/tech/filters/passiveHLxo.html
dave
Just wanted to update a bit. The panels are all cut, I've gotten the cabinets assembled to the point where I need to measure and cut the portion of the driver brace that connects the two drivers. Between the weather, holiday, and life in general it's been a no go getting the table saw outdoors to make the cuts, so I've been doing some odds and ends like cleats on the panels, drilling the binding post mounts, and cutting the lining for the cabinet walls. Not being able to use the table saw I had given up on cutting cleats for a bit, until I read the "Plywood Joining" thread in this forum. Someone had suggested using quarter round molding as a cleat in the corners, quite a brilliant suggestion as I had about 24 board feet sitting in my basement. It works like a charm.
With the dreary weather I did get a chance to play around with my sub placement a bit. Finally found a placement that isn't boomy. Got to turn the gain up to about half way and rock out a bit, which is always good.
Twelve more cuts with the table saw and I should be back inquiring about the right way to wire the drivers up.
With the dreary weather I did get a chance to play around with my sub placement a bit. Finally found a placement that isn't boomy. Got to turn the gain up to about half way and rock out a bit, which is always good.
Twelve more cuts with the table saw and I should be back inquiring about the right way to wire the drivers up.
I just wanted to mention that this thread was one of the things that inspired me to go ahead with building my (new) Fonken167 floorstanders with bass support in the bottom section.
Fonken 167 thread
Thanks for all the info here on passive crossovers, etc- I'll report back once I get my biamp setup in a decent case, and playing upstairs with the new speakers.
Cheers
John
Fonken 167 thread
Thanks for all the info here on passive crossovers, etc- I'll report back once I get my biamp setup in a decent case, and playing upstairs with the new speakers.
Cheers
John
VictoriaGuy said:
I really like how they came out. You've got the 167s running full range with the Eastechs coming in at 300hz, correct? Mine are split at 120hz, I have a feeling that I'll be playing around with that figure a bit once I get mine up and running finally.
Thanks for posting, your results gave me the kick in the behind I needed to get started again. After getting the rest of the cuts done and everything cleaned up I was psyching myself out comtemplating the glue up.
I'm finally at the point where the only thing I have left to glue is the top panels for the cabinets. I'd had some trouble getting over my fear of gluing the panels together, I guess I got intimidated thinking it wasn't going to go together well. My cuts actually came out better then I expected, probably the most square and uniform panels that I've done yet. I learned two things when I built the Fonkens, first was the importance of setting up the table saw correctly, the second was knowing when to call it a night. I found that when I quit as soon as I start convincing myself to try and get one more thing done for the evening past what I'd planned to do, I don't make as many stupid mistakes.
Now I've got to figure out how to wire the drivers. When I bought the drivers from Dave he provided me with their measured specs, including Re. Three of the four drivers measured 7.3 ohms, the other 6.9. The drivers have dual voice coils, and they are advertised as being 4 ohm nominal, so I'm assuming the measured numbers are gotten when the 2 coils are wired in series. My amplifier is rated for driving a nominal load of between 4 and 16 ohms in stereo. Should I/would I be ok to wire the two drivers in series, or would that be too low of an impedance to play nice with my amp?
Now I've got to figure out how to wire the drivers. When I bought the drivers from Dave he provided me with their measured specs, including Re. Three of the four drivers measured 7.3 ohms, the other 6.9. The drivers have dual voice coils, and they are advertised as being 4 ohm nominal, so I'm assuming the measured numbers are gotten when the 2 coils are wired in series. My amplifier is rated for driving a nominal load of between 4 and 16 ohms in stereo. Should I/would I be ok to wire the two drivers in series, or would that be too low of an impedance to play nice with my amp?
Yes, i wired them in series to measure them. Wire each driver in series, and then parallel the 2 drivers will give you a 4 ohm loudspeaker.
In the Monsoons they came out of they actually had 2 amplifiers, one driving each 4 ohm voice coil (a clever strategy to get more ommf out of the 12V single rail transformers).
dave
In the Monsoons they came out of they actually had 2 amplifiers, one driving each 4 ohm voice coil (a clever strategy to get more ommf out of the 12V single rail transformers).
dave
10 days after that last post my wife gave birth to our son.
I'd gotten the speakers together to listen to but without any type of finish. Been lsitening to the set up here and there, but not critically 'til recently. Good extension and impact but I'm not thrilled with the imaging when the active XO is in the equation. Placement of instruments isn't real convincing.
Would upgrading the op amps in the XO to the LM4562 be worth a shot?
I'd gotten the speakers together to listen to but without any type of finish. Been lsitening to the set up here and there, but not critically 'til recently. Good extension and impact but I'm not thrilled with the imaging when the active XO is in the equation. Placement of instruments isn't real convincing.
Would upgrading the op amps in the XO to the LM4562 be worth a shot?
Hi JVA,
That's a nice looking driver. How do you feel about its performance? I would be interested in seeing some distortion measurements, I wonder if any are available on the net (just took a look quickly for the moment). Anyway, it's very nice looking - it would make a sharp looking high-end 2 way, though CSS suggests crossing 'low', and FR seems to back that up. Sensativity is a little on the low side, however, I wonder if power compression would be an issue at moderate SPL.
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