i would suggest these speakers
at a good prices and buy two pairs and a good tweetr in a MTM combo
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=360156392399&_trkparms=tab=Watching
at a good prices and buy two pairs and a good tweetr in a MTM combo
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=360156392399&_trkparms=tab=Watching
Big_Bill said:
How wide is the box?
With my latest experiments i'd consider a Fostex FF85. Run a piece of 4" PVC from behind the tweer cutout all the way to the back of the box. Ream out the tweeter hole as needed to fit the FF85. Open out the back of the box so that the PVC pipe turns into a TL. Stuff with increasing density to the terminus. XO just below (o.71-0.9 x) the baffle-step frequency (4560/box width in inches).
Is the xo between 15" and AV8 active (it should be). You could probably drop the XO between it and the AV8 a bit (75-80 Hz)
dave
re:'When you say "actual", do you mean multi meter actual, or the resistance on the chart curve where it corresponds to the desired frequency points?'
the second - which makes it a bit harder... but because you'll probably have to pad the driver, you might be able to get away with adjusting an L-pad by ear (as long as you're in the ball park in the first place...)
the second - which makes it a bit harder... but because you'll probably have to pad the driver, you might be able to get away with adjusting an L-pad by ear (as long as you're in the ball park in the first place...)
sure... probably best place to start is to post your existing xover..it helps if the driver parameters and freq response curves are available too, but show us what you've got...
bear in mind that others may disagree with my way of doing things (and sometimes for good reason, we all have our limitations
)
P.S. a long weekend is about to start here, so I may be online only intermittently for the next couple of days
bear in mind that others may disagree with my way of doing things (and sometimes for good reason, we all have our limitations
)P.S. a long weekend is about to start here, so I may be online only intermittently for the next couple of days
I'll be here the whole of the LWE, I'm not allowed on the mountain just yet.
( Queens Birthday Long WE is the traditional start to the OZ ski season )
I'd like to see the original XO, it may not be 3-way, but 3.5-way.
i have to go with Dave on this one tho, I've just looked at the FR for the 8inch and I'd be crossing way down 250 or 300Hz
Also second Petes disclaimer, my opinions aren't always
( often/sometimes ) right.
Regards
Ted
( Queens Birthday Long WE is the traditional start to the OZ ski season )
I'd like to see the original XO, it may not be 3-way, but 3.5-way.
i have to go with Dave on this one tho, I've just looked at the FR for the 8inch and I'd be crossing way down 250 or 300Hz
Also second Petes disclaimer, my opinions aren't always
( often/sometimes ) right.
Regards
Ted
Big_Bill, Here’s an outline of how I think you could proceed, assuming you don’t have the capacity to run impedance plots, and want to change the existing crossover as little as possible:
1: Measure resistance of driver to be replaced
2: Select new driver with equal or higher sensitivity than old, Re equal or higher than measured resistance of old, and with flat freq response one octave either side of crossover points min.
3: Zobel the new driver so that it matches the resistance of the old – this will make the impedance and hence response of crossover components predictable
4ut an adjustable L-pad in the circuit and adjust the level of the new driver (after extensive listening – your initial impulse may be to have the new driver too far forward in the mix, but this may become fatiguing)
5: Measure resistance of both arms of the L pad and replace with fixed resistors, but put the top resistance before the crossover components for the mid driver, to allow further tweaking without affecting crossover freq too much. (I can draw diagrams to make this clearer)
don’t forget to ask questions here along the way to clarify anything
Dave’s idea is good too, but needs a new crossover; another alternative is to use a tweeter that will respond down to about 1.5KHz (SEAS 27TBFC/G would do it) and use steep xover slopes, but this would require a new crossover too
1: Measure resistance of driver to be replaced
2: Select new driver with equal or higher sensitivity than old, Re equal or higher than measured resistance of old, and with flat freq response one octave either side of crossover points min.
3: Zobel the new driver so that it matches the resistance of the old – this will make the impedance and hence response of crossover components predictable
4
ut an adjustable L-pad in the circuit and adjust the level of the new driver (after extensive listening – your initial impulse may be to have the new driver too far forward in the mix, but this may become fatiguing)5: Measure resistance of both arms of the L pad and replace with fixed resistors, but put the top resistance before the crossover components for the mid driver, to allow further tweaking without affecting crossover freq too much. (I can draw diagrams to make this clearer)
don’t forget to ask questions here along the way to clarify anything
Dave’s idea is good too, but needs a new crossover; another alternative is to use a tweeter that will respond down to about 1.5KHz (SEAS 27TBFC/G would do it) and use steep xover slopes, but this would require a new crossover too
Ok, I’ve assumed that there is an existing xover…if not, carte blanche, here’s what I’d do:
First measure the actual resistance of the 15” driver with your multimeter, (subtract the resistance of the leads themselves, on my DMM they’re 0.4 ohms). We’ll use this as the Re for this driver.
A quick sim of the AV8 in WINISD shows that 100-150 Hz would be an OK crossover point for the Adire
For the crossover point of the 15”, use the front baffle width at the height of the AV8, and calculate it as Dave said; I do it metric so use (115/width in metres) for BSC freq.
Plug these numbers in the first order calculator on this page:
http://ccs.exl.info/calc_cr.html#second
which, using Re as the Impedance value (in the low-mid range this is close),
for the AV8 gives C of 193uF at 150 Hz. Change the freq to the BSC freq calculated above to get the L value for your 15”.
Next, scroll down the Zobel calculator and work a Zobel out for the Adire: 50uF and 6.8 ohms.
Using a zobel will let us calculate the high pass section of the xover using Re.
Here, I’m going to assume a 3-way crossed at 1.5kHz to a Seas 27tbfcg
For the low pass section, and so close to that peak, I’d go 3rd order on the AV8:
I get L2: 0.875mH, C3:26uF,L3:0.29mH (you may want to tweak the xover freq a bit to see if you can get standard inductor values available to you, but not too much)
Crossing this low is close to the limit for this tweeter, but it worked for Jay:
http://www.geocities.com/woove99/Spkrbldg/Usher_2way/XO_8945P_TBFCG.gif
you could probably use that schematic for the tweeter changing only the L pad values.
This calculator will help you with that: http://www.sengpielaudio.com/calculator-Lpad.htm
(note the polarity of the tweeter should be reverse for 2nd order)
OK. Take a deep breath, stand back and listen for a few days/weeks/months…then start tweaking…
If you’ve still got a problem with that AV8 peak, you may need to add a notch filter, but that could get messy…
First measure the actual resistance of the 15” driver with your multimeter, (subtract the resistance of the leads themselves, on my DMM they’re 0.4 ohms). We’ll use this as the Re for this driver.
A quick sim of the AV8 in WINISD shows that 100-150 Hz would be an OK crossover point for the Adire
For the crossover point of the 15”, use the front baffle width at the height of the AV8, and calculate it as Dave said; I do it metric so use (115/width in metres) for BSC freq.
Plug these numbers in the first order calculator on this page:
http://ccs.exl.info/calc_cr.html#second
which, using Re as the Impedance value (in the low-mid range this is close),
for the AV8 gives C of 193uF at 150 Hz. Change the freq to the BSC freq calculated above to get the L value for your 15”.
Next, scroll down the Zobel calculator and work a Zobel out for the Adire: 50uF and 6.8 ohms.
Using a zobel will let us calculate the high pass section of the xover using Re.
Here, I’m going to assume a 3-way crossed at 1.5kHz to a Seas 27tbfcg
For the low pass section, and so close to that peak, I’d go 3rd order on the AV8:
I get L2: 0.875mH, C3:26uF,L3:0.29mH (you may want to tweak the xover freq a bit to see if you can get standard inductor values available to you, but not too much)
Crossing this low is close to the limit for this tweeter, but it worked for Jay:
http://www.geocities.com/woove99/Spkrbldg/Usher_2way/XO_8945P_TBFCG.gif
you could probably use that schematic for the tweeter changing only the L pad values.
This calculator will help you with that: http://www.sengpielaudio.com/calculator-Lpad.htm
(note the polarity of the tweeter should be reverse for 2nd order)
OK. Take a deep breath, stand back and listen for a few days/weeks/months…then start tweaking…
If you’ve still got a problem with that AV8 peak, you may need to add a notch filter, but that could get messy…
Ralph Waters has some NOS Coral domes for sale at a ridiculously low price.
http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=260394983718
Of course you would need to completely rework the cross-over, but with a steeper slope it may be possible to use this unit as low as 800Hz.
I'd sent a message to Ralph and ask him for his opinion
http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=260394983718
Of course you would need to completely rework the cross-over, but with a steeper slope it may be possible to use this unit as low as 800Hz.
I'd sent a message to Ralph and ask him for his opinion
How did this speaker design and driver selection come to be? You got any pictures?
The right combination of drivers in the right size enclosure is key to everything working together and sounding fantastic. Any chance you would cut the top part of the enclosure off, the part where the mid and tweeter are, and make it narrower? The wide 22" baffle will cause baffle step issues for the midrange and tweeter frequencies.
After perusing this thread a few times it seems to me you need to adjust your crossover points and add a mid driver. The 15" should handle just the sub frequencies up to about 70hz or so. The 8" from there up to at most 300hz which gives you more options for a midrange driver. The 1" tweeter crossed much higher where the midrange leaves off.
It is very desirable to have a midrange that covers from the 200hz range to as high as possible like say 6k or higher so there are no crossovers in that most critical frequecy range as our ears are most sensitive to the coloration they add.
The right combination of drivers in the right size enclosure is key to everything working together and sounding fantastic. Any chance you would cut the top part of the enclosure off, the part where the mid and tweeter are, and make it narrower? The wide 22" baffle will cause baffle step issues for the midrange and tweeter frequencies.
After perusing this thread a few times it seems to me you need to adjust your crossover points and add a mid driver. The 15" should handle just the sub frequencies up to about 70hz or so. The 8" from there up to at most 300hz which gives you more options for a midrange driver. The 1" tweeter crossed much higher where the midrange leaves off.
It is very desirable to have a midrange that covers from the 200hz range to as high as possible like say 6k or higher so there are no crossovers in that most critical frequecy range as our ears are most sensitive to the coloration they add.
901Fixer said:
Well it was a project I did with my father’s best friend. I was only 18 years old (I am now 36) and my father had just died. My father’s friend whom I barely knew came up with the project, I now think as a bonding gesture.
He was a carpenter and had an idea for a set of speakers with no parallel baffles (equilateral triangles). We both built a set. I now know they were designed poorly from the start! I had a set of my father’s 15” Tru-Sonic drivers reconed and repapered at the “Speaker Doctor” here in Charlotte NC. And wanted to build a set around them. Somehow we determined they needed 9 cubic feet of sealed air space sealed, they where over six feet tall! The rest of the drivers were all sealed back. They were put in storage soon after completion, as they were huge and sounded like crap!
I was cleaning out my storage bin, which had grown out of control. That’s when I ran across them. I couldn’t bring my self to throw them away as they remind me of my father, and that time of my life.
I felt I had to do something with them, so I cut the cabinets down to 40.5” tall and bought some inexpensive Pyle PPA 15’s to replace the old TRU-Sonics. I thought the Pyle would do all right for one hundred hertz and bellow. The tech at Pyle said they would work best for me at 2.5 cubic feet sealed, so I partitioned the cabinet internally for that driver. I had inductor’s wound by “Chokes Unlimited” at 12.7 Mh and placed them in line with the 15” driver’s. A new friend I met recently sold me two Adire Audio AV8’s for twenty-five dollars apiece. I partitioned the cabinet internally at 1.5 cubic feet sealed for the AV8 per advice here and on AV Forum. That left ten inches at the top of the cabinet, which is where I mounted the (circa 1990’s) 3.5” Pyle closed back midrange and the 1” soft dome tweeter.
I am looking for any help I can get. The 3.5-sealed back Pyle is a real turd! Should I replace just the 3.5 with a quality upper mid or should I replace the tweeter for one with a lower frequency response and remove the upper mid? Where should this rig be crossed over? What type of crossover would be best? What would those crossover component values be? How should they be assembled? I am only familiar and or comfortable with my understanding of first order band passes.
Any help would be greatly appreciated!
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