Honestly not sure. I'd comfortably spend $200 per tower on the woofers I think. If it gets me close to a near flat to 30hz goal in a 3~5 ft^3 volume net tower.
Very best,
Just pulled out a GRS 8SW4HE driver and measured it.
DATS with measured T&S:
Near field sweep:
Totally dead from 700hz and up, could hear it go.
But that 400~600 range could be possible? Maybe? Kinda rough?
Crossing with this planar (PT6816-8):
Right around 500hz? 600hz? Doable?
I know the sensitivity doesn't match, but could pad the planar back down to flatten it up.
Very best,
DATS with measured T&S:
Near field sweep:
Totally dead from 700hz and up, could hear it go.
But that 400~600 range could be possible? Maybe? Kinda rough?
Crossing with this planar (PT6816-8):
Right around 500hz? 600hz? Doable?
I know the sensitivity doesn't match, but could pad the planar back down to flatten it up.
Very best,
The work was already done for you the manufacture response graph clearly shows no response to 700 Hz
most of that is dictated by the voice coil inductance around 2.7mH
To have more upper bandwidth it would need to be way lower more than half for a 4 ohm coil.
Perfect example is the 4 ohm SD270A-88 the inductance is down to 1.1 mH which is why it has more bandwidth.
Inductance of voice coil creates a low pass filter in all drivers.
Even in a simple model like WinIsd it will include electro mechanical behavior in the transfer function.
In this case if you entered the inductance in you driver data in WinIsd the transfer function would even show the
highend roll off. Of course the actual real world response is shown with the datasheet or measurement. WinIsd wont predict cone response.
It is only transfer function of the theoretical filter of the driver. I dont think your models showed roll off because inductance ( Le) was
not entered
Anyways -3dB is close to 120 Hz where as a sub 100 to 60 Hz is completely normal crossover.
It simply will not work and as mentioned the inductors would be incredible large and expensive.
wont work, needs midbass driver. Easily fixed with proper woofers for a 2 way
Thanks,
While the manufacturer does publish something, thankfully, I'm used to it being very different when measured when it comes to budget GRS drivers. Fun cheap drivers, but the publications are not close I find. I measure other drivers that are pretty good and they are very close to their published spec. So I just wanted to confirm what the cheap GRS was doing.
Updated in previous post. Pretty similar response. The T&S are a bit different as expected, but not in a useful way. Still, good to know what it is actually doing there.
Agreed with what you're saying, I'm just seeing if it's possible to stretch this little driver to 500~600hz. I could hear it audibly and measured it. If it were indeed possible to cross this driver, two of them at 500~600hz with the planar mid, I would try it. I have them, so why not? I can cut some holes on scrap just to see how it looks on a baffle width.
Very best,
Thanks, interesting!
I was thinking taller, to take advantage of some lovely oak slabs. Planar, 1 woofer in the front, 1 woofer opposed in the rear (dual opposed, cancel vibrations internally), 1 port in the front. Keep a lot of baffle area showing to show off the lovely oak slab under some epoxy.
Very best,
Last edited:
Just a quick whirl in Xsim:
It's not pretty. But it looks functional as a starting point perhaps.
Any glaring mistakes?
Totally doing this wrong?
Ditch this driver?
PT6816-8 x 1
8SW4HE x 2 (in series)
Xsim file attached for play.
Very best,
It's not pretty. But it looks functional as a starting point perhaps.
Any glaring mistakes?
Totally doing this wrong?
Ditch this driver?
PT6816-8 x 1
8SW4HE x 2 (in series)
Xsim file attached for play.
Very best,
For those GRS...even though they have output up to 400-500Hz, you really want them to be pretty flat well past that. Then, even when you incorporate the crossover, they will likely be contributing to the sound some at even 2Khz.
The DSA215's do not go near as low as you want. If you are wanting in the low 30's you need drivers with low Fs.
Two others for you to simulate since your budget is actually not that small. Singles only though, since a pair per side would blow the budget. The advantage here is that these will be a step up in sound quality from the Dayton Classics and other $40 drivers.
RS270
RSS265
(Speaking of budget, PE always has sales on the holidays. If you ended up with a pair of RSS265's (one for each tower) that is not cheap, but you can surely get 12-14% off at Halloween or CyberMonday if you are willing to wait.)
[Off topic (but indirectly related) - I will be building a speaker in the spring with the MarkAudio CHP-90 and a Scan-speak Discover 10" woofer (because I have them on hand). I had seen your build thread and love it and appreciate the comments on the MarkAudio. Your comments and a few other people's convinced me to go with the CHP-90.]
The DSA215's do not go near as low as you want. If you are wanting in the low 30's you need drivers with low Fs.
Two others for you to simulate since your budget is actually not that small. Singles only though, since a pair per side would blow the budget. The advantage here is that these will be a step up in sound quality from the Dayton Classics and other $40 drivers.
RS270
RSS265
(Speaking of budget, PE always has sales on the holidays. If you ended up with a pair of RSS265's (one for each tower) that is not cheap, but you can surely get 12-14% off at Halloween or CyberMonday if you are willing to wait.)
[Off topic (but indirectly related) - I will be building a speaker in the spring with the MarkAudio CHP-90 and a Scan-speak Discover 10" woofer (because I have them on hand). I had seen your build thread and love it and appreciate the comments on the MarkAudio. Your comments and a few other people's convinced me to go with the CHP-90.]
No worries! I'm happy to be told frankly that its bad so I can easily just shelve them again and move on. I bought them a while back, lovely little drivers, but finding that they're only ever going to be subs or blended with full range drivers at much lower frequencies like 100hz and will require low pass filter as no passive crossover will handle it at 80~100hz. I'm ok with hard love! 😀 I appreciate the frankness!
I can now move on back to 8's or 10's woofers.
Very best,
Thanks! I will explore these! I'll focus on lower Fs woofers and see how many I can budget into things. I'm fine with the classics even, just still exploring.
MarkAudio is great. They even measure close to their published spec which is always wild to me. I've yet to try one of their larger drivers, that will be soon, one of those 6~7" ones.
Any opinion on using 2~4x inexpensive woofers compared to 1 more expensive one for this?
Very best,
Thanks, I will look this one up! I haven't done models with the newest drivers yet.
Very best,
Very interesting, thanks for the models, that looks pretty smooth. This is a huge speaker for only getting to 40~50hz though. Hrm. Will have to ponder on this.
I realize I'm asking for a lot to get to 30hz without just integrating a separately powered subwoofer. Maybe it can't be done reasonably well. I know I could just throw in a bunch of woofers and use active DSP to get exactly what I want. But I'm trying to not just use DSP as a crutch, which I'm used to doing, and try to do something passive that will just work on any old system without advanced handling.
I would happily shove 8 woofers into a tower, if it gets me there. I realize it will get less and less flat if I add more woofers. A hard balance to get a flat peak at the port output vs excursion limits on these low xmax woofers at lower power, etc. They likely won't see more than 30 real watts in reality, but I'm trying to plan it around seeing 100w at most. These are not meant to get loud from a distance, the will be in a living room and used for general purpose media at lower volumes. Mainly just gives me a reason to build something lovely with big oak slabs (which my wife loves the look of, so can't turn down the opportunity to build something and it be wanted by the wife!).
I'll explore! Thanks again!
Very best,
Ok, gonna try and organize some potential woofers, not subwoofers (thanks, I needed this over and over!). Just browsing PartsExpress, just looked at drivers in this size range with lower Fs, and ok xmax to see what might be a good fit.
I will happily use 1~4 drivers if it means getting a near flat output to 30hz approximately. If it's closer to 40hz, then I might as well not do large towers or switch design to include an integrated sub. I'd like to not do that though, unless I must. I'd much prefer just to go passive on this one if I can for simplicity for use with any electronics. I may not be able to do this. I'm not sure. Hence the thread! And I appreciate everyone's help so far, it's been great to not get tied up with something that won't work!
+++++++++++++++++++
Questions:
Will it matter a ton if I use 1 to 4 drivers in series/parallel for crossover purposes other than the obvious impedance difference? I don't know the practical needs of other components if I add more woofers. Mainly asking so that I can consider groups of 2~4 drivers to allow more excursion and increase overall sensitivity by having more cone area as this speaker is not going to receive a lot of power, so the more sensitive I can get it, the better. I would even go as far as 8 smaller drivers, if it would help get to that goal (8 x 8" drivers for example, 4 on the front, 4 on the back in opposition but in phase, or even 6.5" drivers x 8, whatever works).
+++++++++++++++++++
10" woofers:
RS270-8
Fs 29hz
88.7db sensitivity
6.6mm xmax
https://www.parts-express.com/Dayton-Audio-RS270-8-10-Reference-Woofer-295-357?quantity=1
DC250-8
Fs 24.9hz
88.4db sensitivity
4.5mm xmax
https://www.parts-express.com/Dayton-Audio-DC250-8-10-Classic-Woofer-295-315?quantity=1
SIG225-4
Fs 39hz
91.2db sensitivity
6mm xmax
https://www.parts-express.com/Dayto...nature-Series-Woofer-4-Ohm-295-656?quantity=1
8" woofers:
DC200-8
Fs 30hz
87db sensitivity
4.5mm xmax
https://www.parts-express.com/Dayton-Audio-DC200-8-8-Classic-Woofer-295-310?quantity=1
HiVi M8N
Fs 29hz
86db sensitivity
5.8mm xmax
https://www.parts-express.com/HiVi-M8N-8-Aluminum-Magnesium-Woofer-297-446?quantity=1
DS215-8
Fs 34.3hz
89.9db sensitivity
5.5mm xmax
https://www.parts-express.com/Dayton-Audio-DS215-8-8-Designer-Series-Woofer-295-430?quantity=1
RS225-8
Fs 28.3hz
86.8db sensitivity
7mm xmax
https://www.parts-express.com/Dayton-Audio-RS225-8-8-Reference-Woofer-295-356?quantity=1
I'll model some of these when I get home from work tonight.
++++++++++++++++++++++++++++++++++++++++++++++++++
The alternative, if I cannot get this to work will involve probably an amp with DSP or plate amp with built in DSP and simply run active subwoofers in the towers with a high low pass filter to a wide band driver.
Example wide band drivers:
MarkAudio CHN110
Take it down to 100~120hz with the enclosure
https://www.madisoundspeakerstore.com/approx-6-fullrange/markaudio-chn110-silver-6.75-full-range/
Low pass it with a plate amp between 100~200hz with something like this:
1 x of these plate amps per tower (so need 2).
https://www.parts-express.com/Dayto...-Subwoofer-Plate-Amplifier-300-806?quantity=1
And have that actively power whatever sub drivers I want. Could go sealed. It has a +6db boost at 30hz. I could model that and see if I like the results on some sub drivers. Or go for bass reflex and peak it around 30hz and use that too.
This would be much easier. No crossover. Just involves more electronics and requires pre-amp out from the source, so it would always need an AVR or stereo amp with pre-amp out for subs, etc. I'd probably always have such a thing, but, I just like the idea of not needing it and could work on basic analog. I could also use plate amps that have high level inputs and outputs too, to bypass that electronics need. That would work. It would just require a ton of cables running around. But it is an option...
Very best,
I will happily use 1~4 drivers if it means getting a near flat output to 30hz approximately. If it's closer to 40hz, then I might as well not do large towers or switch design to include an integrated sub. I'd like to not do that though, unless I must. I'd much prefer just to go passive on this one if I can for simplicity for use with any electronics. I may not be able to do this. I'm not sure. Hence the thread! And I appreciate everyone's help so far, it's been great to not get tied up with something that won't work!
+++++++++++++++++++
Questions:
Will it matter a ton if I use 1 to 4 drivers in series/parallel for crossover purposes other than the obvious impedance difference? I don't know the practical needs of other components if I add more woofers. Mainly asking so that I can consider groups of 2~4 drivers to allow more excursion and increase overall sensitivity by having more cone area as this speaker is not going to receive a lot of power, so the more sensitive I can get it, the better. I would even go as far as 8 smaller drivers, if it would help get to that goal (8 x 8" drivers for example, 4 on the front, 4 on the back in opposition but in phase, or even 6.5" drivers x 8, whatever works).
+++++++++++++++++++
10" woofers:
RS270-8
Fs 29hz
88.7db sensitivity
6.6mm xmax
https://www.parts-express.com/Dayton-Audio-RS270-8-10-Reference-Woofer-295-357?quantity=1
DC250-8
Fs 24.9hz
88.4db sensitivity
4.5mm xmax
https://www.parts-express.com/Dayton-Audio-DC250-8-10-Classic-Woofer-295-315?quantity=1
SIG225-4
Fs 39hz
91.2db sensitivity
6mm xmax
https://www.parts-express.com/Dayto...nature-Series-Woofer-4-Ohm-295-656?quantity=1
8" woofers:
DC200-8
Fs 30hz
87db sensitivity
4.5mm xmax
https://www.parts-express.com/Dayton-Audio-DC200-8-8-Classic-Woofer-295-310?quantity=1
HiVi M8N
Fs 29hz
86db sensitivity
5.8mm xmax
https://www.parts-express.com/HiVi-M8N-8-Aluminum-Magnesium-Woofer-297-446?quantity=1
DS215-8
Fs 34.3hz
89.9db sensitivity
5.5mm xmax
https://www.parts-express.com/Dayton-Audio-DS215-8-8-Designer-Series-Woofer-295-430?quantity=1
RS225-8
Fs 28.3hz
86.8db sensitivity
7mm xmax
https://www.parts-express.com/Dayton-Audio-RS225-8-8-Reference-Woofer-295-356?quantity=1
I'll model some of these when I get home from work tonight.
++++++++++++++++++++++++++++++++++++++++++++++++++
The alternative, if I cannot get this to work will involve probably an amp with DSP or plate amp with built in DSP and simply run active subwoofers in the towers with a high low pass filter to a wide band driver.
Example wide band drivers:
MarkAudio CHN110
Take it down to 100~120hz with the enclosure
https://www.madisoundspeakerstore.com/approx-6-fullrange/markaudio-chn110-silver-6.75-full-range/
Low pass it with a plate amp between 100~200hz with something like this:
1 x of these plate amps per tower (so need 2).
https://www.parts-express.com/Dayto...-Subwoofer-Plate-Amplifier-300-806?quantity=1
And have that actively power whatever sub drivers I want. Could go sealed. It has a +6db boost at 30hz. I could model that and see if I like the results on some sub drivers. Or go for bass reflex and peak it around 30hz and use that too.
This would be much easier. No crossover. Just involves more electronics and requires pre-amp out from the source, so it would always need an AVR or stereo amp with pre-amp out for subs, etc. I'd probably always have such a thing, but, I just like the idea of not needing it and could work on basic analog. I could also use plate amps that have high level inputs and outputs too, to bypass that electronics need. That would work. It would just require a ton of cables running around. But it is an option...
Very best,
Last edited:
So, thinking about it at work instead of working 🙂whistle:☕) I guess I could do both of these things to make a complete full range tower.
Planar wideband crossed to a woofer at 600~700hz with a 2 way passive crossover. I'll just match similar woofer sensitivity to the planar. Single driver can probably work here, 2 if I need more sensitivity. It just needs to get down to 100~120hz, but could go lower like 60~80hz range even. Though probably 100hz to be realistic and keep it sealed so there's no phase mess to deal with.
Then put subwoofer drivers in with their own plate amp (or external amp, more likely) and low pass filter built in. Can push this to 25hz or so instead.
2 way tower with integrated active subs in each one.
Very best,
Planar wideband crossed to a woofer at 600~700hz with a 2 way passive crossover. I'll just match similar woofer sensitivity to the planar. Single driver can probably work here, 2 if I need more sensitivity. It just needs to get down to 100~120hz, but could go lower like 60~80hz range even. Though probably 100hz to be realistic and keep it sealed so there's no phase mess to deal with.
Then put subwoofer drivers in with their own plate amp (or external amp, more likely) and low pass filter built in. Can push this to 25hz or so instead.
2 way tower with integrated active subs in each one.
Very best,
Hrm,
So maybe pair these in a 2 way around 700hz:
https://www.parts-express.com/GRS-PT6816-8-8-Planar-Slim-Tweeter-8-Ohm-272-128?quantity=1
https://www.parts-express.com/Dayto...Power-Midbass-Driver-8-Ohm-295-636?quantity=1
Take that to about 100hz sealed. Then integrate active subs in the same enclosure with its own low pass filter to avoid needing huge passive crossovers and stuff.
And then the rest of the tower can be sub drivers and active powered separate with its own low pass filter. Either plate amps or separate outboard amp, either way, simple. Sort of answers all the problems.
It's not the same as a wide band planar on its own and woofers, but it's close.
Very best,
So maybe pair these in a 2 way around 700hz:
https://www.parts-express.com/GRS-PT6816-8-8-Planar-Slim-Tweeter-8-Ohm-272-128?quantity=1
https://www.parts-express.com/Dayto...Power-Midbass-Driver-8-Ohm-295-636?quantity=1
Take that to about 100hz sealed. Then integrate active subs in the same enclosure with its own low pass filter to avoid needing huge passive crossovers and stuff.
And then the rest of the tower can be sub drivers and active powered separate with its own low pass filter. Either plate amps or separate outboard amp, either way, simple. Sort of answers all the problems.
It's not the same as a wide band planar on its own and woofers, but it's close.
Very best,
