Hi All,
My Current Speaker is a 10 inch Dayton RS270 in sealed cabinet driven actively XO @200hz 12db/oct.
Driven from Modwright KWA SE 100 is a Peerless 830883 mid open baffle 200-3000hz 12db/oct. and Fountek Neo 3.0 tweeter XO at 3200 18db/oct.
Planned future improvements: Thinking of building the GR Research H Frame with 2 12’s and the servo amps to replace the RS270’s. XO at about 200hz.
I want to keep the Fountek, but it likes to be crossed over “higher the better”.
Next I was thinking of maybe replacing the Peerless mid, but with what? Especially if I want to go higher than 3khz on the higher end, 200hz-3000+ is a bit of a stretch for that driver. I’d like to not have to go 4 way. I was considering ScanSpeak M18/4631T. 92 db sensitivity and looks like it would go down to 200hz and decent Q for OB. But I was warned about using it past 2khz as the response gets ragged.
I’d like to have a system eff of 91db and need to cover a wide frequency range. Do I need to look at full range drivers or maybe go to a 4 way system?
Would the SS driver be a suitable replacement? Madisound at first said it would be much better than the Peerless until they looked at the FR graph. Advise is appreciated. Thanks Much.
My Current Speaker is a 10 inch Dayton RS270 in sealed cabinet driven actively XO @200hz 12db/oct.
Driven from Modwright KWA SE 100 is a Peerless 830883 mid open baffle 200-3000hz 12db/oct. and Fountek Neo 3.0 tweeter XO at 3200 18db/oct.
Planned future improvements: Thinking of building the GR Research H Frame with 2 12’s and the servo amps to replace the RS270’s. XO at about 200hz.
I want to keep the Fountek, but it likes to be crossed over “higher the better”.
Next I was thinking of maybe replacing the Peerless mid, but with what? Especially if I want to go higher than 3khz on the higher end, 200hz-3000+ is a bit of a stretch for that driver. I’d like to not have to go 4 way. I was considering ScanSpeak M18/4631T. 92 db sensitivity and looks like it would go down to 200hz and decent Q for OB. But I was warned about using it past 2khz as the response gets ragged.
I’d like to have a system eff of 91db and need to cover a wide frequency range. Do I need to look at full range drivers or maybe go to a 4 way system?
Would the SS driver be a suitable replacement? Madisound at first said it would be much better than the Peerless until they looked at the FR graph. Advise is appreciated. Thanks Much.
The new SBAcoustics Satori 5" mid is exactly what you need!
SB Acoustics :: <font color="#FFFF00">NEW!</font> 5" SATORI MR13P-4
You can do LR2 at 3.5khz no problem with the Fountek and the Satori. Don't forget to align the acoustic centers on the baffle which will allow you to get the two drivers closer together to avoid any vertical lobing. Flush mount the Fountek and surface mount the Satori mid a bit over the Fountek's faceplate. The Satori will easily do 200hz 3rd order.
Don't forget to keep the baffle wide to offset losses though or your 91db mid will be more like 85db by the time you get to 200hz.
For greater efficiency, there's also the B&C 6md38 midrange at 95db whose upper response is just as smooth as the Satori but won't make 200hz nor does it have healthy enough xmax for OB use below 250hz.
SB Acoustics :: <font color="#FFFF00">NEW!</font> 5" SATORI MR13P-4
You can do LR2 at 3.5khz no problem with the Fountek and the Satori. Don't forget to align the acoustic centers on the baffle which will allow you to get the two drivers closer together to avoid any vertical lobing. Flush mount the Fountek and surface mount the Satori mid a bit over the Fountek's faceplate. The Satori will easily do 200hz 3rd order.
Don't forget to keep the baffle wide to offset losses though or your 91db mid will be more like 85db by the time you get to 200hz.
For greater efficiency, there's also the B&C 6md38 midrange at 95db whose upper response is just as smooth as the Satori but won't make 200hz nor does it have healthy enough xmax for OB use below 250hz.
Looking at the datasheet now, I think they make a larger version of this driver. I have always loved the way SB/Satori sounds. Good build quality as well. I'll check it out.
Just checked theres a 6.5 in unit that looks like it will work, unless I am missing something.
https://www.madisoundspeakerstore.c...16p-4-6-egyptian-papyrus-cone-midrange-4-ohm/
https://www.madisoundspeakerstore.c...16p-4-6-egyptian-papyrus-cone-midrange-4-ohm/
Yes, the center to center spacing for a 3.5khz cross to the Fountek is too far,...youll get a nasty vertical lobe which is a big issue with ribbons since their vertical directivity is already so narrow. You've got a wavelength of just shy of 4" for 3.5khz so from the edge of the radiating surface of the ribbon to the center of the mid should not exceed 4". With the 6.5" driver you'll be at a bit over 5" with the flanges almost touching.......too far IMO.
Also the 6.5" mid is going to start to beam with poor off axis response around 2.3khz so you'll have inconsistent horizontal and vertical directivity at the crossover point which results in pretty uneven power response.
In other words, 5" or smaller........
Also the 6.5" mid is going to start to beam with poor off axis response around 2.3khz so you'll have inconsistent horizontal and vertical directivity at the crossover point which results in pretty uneven power response.
In other words, 5" or smaller........
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Actually, per Jim Griffin (linearray white paper) ribbons don't have a center like a dome does since sound emits from the full length of the element. That eases CTC spacing considerably with ribbons.
HTH
Jim
If you are running an OB mid check the dipole null and roll off. Chances are you are going to loose constant directivity well below a 3.5K x-o point, esp if you baffle is wide enough to support a 200 hz woofer x-o.
In retrospect It looks like a 4-way if you want to keep the Neo-3. ABC dipole can do these simulations.
If you are using a DSP then you can boost the mid LF roll off, but check max SPL
In retrospect It looks like a 4-way if you want to keep the Neo-3. ABC dipole can do these simulations.
If you are using a DSP then you can boost the mid LF roll off, but check max SPL
Thanks Jim. I remember reading this in a post from you over at HTGuide a few years back when the Statements were coming to light. I did mention the edge of the ribbon element and used those dimensions in my suggestions.
P.S. Don't tell anyone but I think Ribbons make the best tweeters! Lol
This is very interesting and i agree with everything said. However, why is it that "hi end" speaker fabricators don't observe this rule? Is there another tradeoff?
The baffle width is 12 inch. It gets down to 200 hz no problem. There seems to be strong energy in the 300-400 hz region. overall system response is good from what I can measure with my Omnimic. So if i go 4 way and i want to cover 200-over 3khz, then I am guessing a 6-7 inch driver and a 3-4 inch upper mid to the ribbon? Also I assume I should keep the lower/upper mid from the same manufacturer for best blending? As always your advise is appreciated. i am a beginner and have much to learn and appreciate your patience.
I'm not sure what "hi end" fabricators you're referring to so I really can't comment on what they do. I can tell you that accomplished crossover designers I've been friends with over the years don't stress nearly as much about driver spacing as DIY folks do. They've simply said you won't hear minor differences and I've found that to be true.
I'm not a crossover guy, Curt is. When I'm designing a cabinet for one of my projects, I observe the one wave length rule with the closer the better as my guideline.
BTW, if you don't know who Jim Griffin is, he's a PHD engineer that is extremely active in DIY. He became very interested in linearray design in the early 2000's and was the behind the scene guy for the basic design layouts for Selah Audio. I think Jim is still teaching at a college in Kentucky. He's a brilliant guy with tons of DIY audio knowledge. Jim may frequent this forum, not sure. I haven't been active here for several years so he may be well known.
Jim
Better is subjective. If you want to maintain an open back mid response then a cone upper mid would be better than a dome.
One compromise would be to design a close back mid chamber to avoid some of the dipole issues.
Thanks Jim for the info. Good to know who the heavy hitters are Lol!!
John, by better I meant driver sound quality.
Closed back mid chamber? then it wouldn't be open baffle anymore (if I use only a single mid) unless you are referring to put a back on one of the 2 mids if I decide to go 4 way.
John, by better I meant driver sound quality.
Closed back mid chamber? then it wouldn't be open baffle anymore (if I use only a single mid) unless you are referring to put a back on one of the 2 mids if I decide to go 4 way.
The Satori drivers are a new class of special with extremely smooth and wide band response. I wouldn't hesitate using the 5" midwoofer from 250hz to 3.5khz open baffle. Four way is just waaaay to complicated to track phase properly and too many XO components to muddle up the detail and dynamics......you'd have to go active and that's a whole nother ball of wax IMO as the digital AD-DA filters are each adding their own special cold signature to what should be as much analog as possible.
Those 12" GR woofers should play clean to 400hz if you have any doubts about the 5" mid. Just look at the Jamo 909 to get an idea of what's possible with a small midrange driver if you're in doubt.
Those 12" GR woofers should play clean to 400hz if you have any doubts about the 5" mid. Just look at the Jamo 909 to get an idea of what's possible with a small midrange driver if you're in doubt.
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Im going passive on the upper end and servo amp XO on the bass. OK, I like the idea of using that driver. In the past I have used the SB29 and it is one of my favorites. seems easier to work with than the Fountek. I understand the 4 way is difficult. So 3.5k is the highest you would bring the satori? I just want to make sure that range for the fountek is proper.
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