Hello all
Running into something that I don't understand
Driver A - 600wrms 8" 18.8mm xmax
Driver B - 200wrms 8" 13.5mm xmax
Test box 18L 34Hz external port
500w signal. Upper trace is driver A and lower is driver B. I don't know how to read this excursion plot. I was expecting driver B to be flapping like crazy with that much power, but it seems comfortable
Is WinISD nuts?
Running into something that I don't understand
Driver A - 600wrms 8" 18.8mm xmax
Driver B - 200wrms 8" 13.5mm xmax
Test box 18L 34Hz external port
500w signal. Upper trace is driver A and lower is driver B. I don't know how to read this excursion plot. I was expecting driver B to be flapping like crazy with that much power, but it seems comfortable
Is WinISD nuts?
Attachments
Driver A
Driver B
I am working on a stereo sub setup with a 500wrms x2 4R amp. Trying to choose between these two drivers for max 18L enclosure and a boost curve centred around 60Hz, flat at 30hz and f3 below 30hz for my particular use
Driver B is more attractive due to even showing working to my targets in a 10L box
I am designing the sub box and port as a speaker stands for the main speakers
If you put 500 Watts into a driver that is only rated to handle 200 Watts you will simply get a burned up voice coil. You might look at the plot of Maximum SPL for each design. You will find this shows where the drivers hit either the Xmax or power limit. By not telling anyone what manufacturer and model number drivers you are looking at you limit the help you will be able to get.
Unfortunately the Text Driver A and Driver B don't appear any different than other text until I hovered the cursor over them. If you entered the Xmax and the maximum power for each driver into the software it should calculate an accurate max SPL plot.
I have entered Pe as 600 for driver A and 200 for Driver B. Still simulating 18L @34hz with 500w signal. This is the max SPL plot. Lowest is driver B, middle driver A and top is the control Dayton Ultimax 8 in its different 30L @32 Hz box
30L is getting out of my targets for space. The Ultimax also seems way louder in its box, but also flapping the way I would expect driver B to
30L is getting out of my targets for space. The Ultimax also seems way louder in its box, but also flapping the way I would expect driver B to
One of these drivers is Dual Voice Coil
Depending how you enter Data
and set Re to 2.8 ohms
And assign series or parallel coils
BL will drastically change by auto calculation.
Without getting sum check errors
BL will be 8 not 6 like the data sheet.
The driver unloads as usual
when there is no sum check errors
BL is closer to 8
500 watts 18L 34 Hz
shown below
keep in mind the driver has a huge magnet stack and basket
the actual box will need to be larger since the driver displaces
so much volume.
Depending how you enter Data
and set Re to 2.8 ohms
And assign series or parallel coils
BL will drastically change by auto calculation.
Without getting sum check errors
BL will be 8 not 6 like the data sheet.
The driver unloads as usual
when there is no sum check errors
BL is closer to 8
500 watts 18L 34 Hz
shown below
keep in mind the driver has a huge magnet stack and basket
the actual box will need to be larger since the driver displaces
so much volume.
Last edited:
Dragon
Which program are you using? Did you have to create a profile for the ZXi? I am using the current version of WinISD. I have last used this years ago when these high excursion low sensitivity drivers first appeared in Australia back in the late 90s with the JL Audio brand. Even then, I had things not turning out like the modelling simulation. I wonder if the program has limitations with extreme drivers
Another Issue could be that the SLS8 is underspeced power handling to place it in its marketing tier. I can well understand the positives in building a "cheap but strong" reputation
With the DVC ZXi8, I added the Re and entered it as single coil 4R nominal driver. I was under the assumption that the TS parameters were with both coils and not for an individual coil. I am unclear about this aspect of data entry. Regardless, this is not the driver in question, it's the SLS8 that's not behaving like a 200watter in simulation. It's SVC and only 200w. I don't know what's going on with this, but seems like I could throw my 1000w at it, and it laps it up
Manual data entry from datasheet in WinISD
For DVC drivers, should the printed numbers be entered and 2vc selected and parallel or series selected? Example, when the datasheet lists Re 2.8+2.8, should just 2.8 be entered and everything else entered as is? I added the Re and chose single coil
Box volume
I assumed that the box volume entered in the box tab in WinISD did not include driver and port displacement. That after modelling, I would then add the driver displacement, port displacement, brace displacement, amp and them figure for material wall thickness to work out cutting dimensions. I need help correcting any misconceptions I may have about this process. I want to do these babies justice 🙂
The model is assuming 17L of volume
and will show behavior in that volume.
Consider this Net volume.
The comment was more towards,
in the real world if you were.
building the box, the actual real box
would need to be larger.
In real world construction.
We still are aiming for net volume as modeled.
But the driver, bracing and port
all have displacement.
So additional volume is needed for Gross Volume.
You figure out the volume of the port, braces and driver
then add that to Net Volume.
Likewise, always use inside dimensions of the enclosure.
Just as a example, not exact numbers, just example.
You modeled with 17 liters.
Driver displacement 1.2 liters
Bracing .5 liters
Port .8 liters
17 + 1.2 + .5 + .8 = 19.5 Liters
The actual enclosure needs to be
19.5 Liters Gross
to perform as 17 Liters Net.
Far as DVC subwoofers and entering into Winisd.
Every data sheet can be different.
I usually specify 2 coils in the WinIsd Driver DataBase
and change Re so when BL auto calculates
it matches the data sheet.
Its better if data sheet specifies if parallel
or series coils used for measurement.
So sometimes you need to change series/parallel
option. then check BL when it auto calculates.
I double or half RE so BL auto calculates
and matches data sheet BL
I am of course also using WinIsd.
I use older version.
all the equation/math is the same.
Newer version they just changed the
graphics and how the tabs work.
It annoys me, so I use older version.
and will show behavior in that volume.
Consider this Net volume.
The comment was more towards,
in the real world if you were.
building the box, the actual real box
would need to be larger.
In real world construction.
We still are aiming for net volume as modeled.
But the driver, bracing and port
all have displacement.
So additional volume is needed for Gross Volume.
You figure out the volume of the port, braces and driver
then add that to Net Volume.
Likewise, always use inside dimensions of the enclosure.
Just as a example, not exact numbers, just example.
You modeled with 17 liters.
Driver displacement 1.2 liters
Bracing .5 liters
Port .8 liters
17 + 1.2 + .5 + .8 = 19.5 Liters
The actual enclosure needs to be
19.5 Liters Gross
to perform as 17 Liters Net.
Far as DVC subwoofers and entering into Winisd.
Every data sheet can be different.
I usually specify 2 coils in the WinIsd Driver DataBase
and change Re so when BL auto calculates
it matches the data sheet.
Its better if data sheet specifies if parallel
or series coils used for measurement.
So sometimes you need to change series/parallel
option. then check BL when it auto calculates.
I double or half RE so BL auto calculates
and matches data sheet BL
I am of course also using WinIsd.
I use older version.
all the equation/math is the same.
Newer version they just changed the
graphics and how the tabs work.
It annoys me, so I use older version.
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If you have the time, may I please request a comparison of results with the SLS8. I think I might learn something on how to interpret the results from your analysis. I am aiming for max 18L net volume with 34hz port. The box is sitar shaped without any flat surfaces and 20mm wall thickness. Sitar body is the sub 18L. Sitar neck will hide folded external port
Your box on the UM8 is way too big. It really should not be in a box larger than 15 ltrs as you have found out why. Also, much more than 200W, and it makes mechanical noises. The xmax = xmech and the cone will smack the frame. It really is a sealed box woofer though, as ported will allow too much xmax.
As others have said, you can' just throw 500W into a 200W thermally rated voice coil, even if the suspension will take it, for more than a few milliseconds.
As others have said, you can' just throw 500W into a 200W thermally rated voice coil, even if the suspension will take it, for more than a few milliseconds.
See, this is what I am talking about regarding my misconceptions. I have been under the impression that WinISD would have algorithms for the power drawn from the amp to reach lengths of excursion at varying frequency and assumed that the program was showing that the driver was in safe zone dynamically
Appreciate your confirmation regarding the UM8. I don't have the experience and expertise to make that call from the simulation, just felt that it was overworking crazy. I really am trying to find very small drivers that can run in a tiny box and use power handling and excursion to meet my targets of 30hz at 0 and F3 below 30hz
Very intrigued by the SLC8. I am making stereo subs that cross at around 300-400hz and sit under the mains as speaker stands, hoping to end up with a system with huge dynamic range ability in the bass guitar zone to take the load of the woofers in the two ways at my listening levels. Just worried about its 200w rating. I'll also be using this speaker set to DJ reggae at small parties and things, so do not want to rely on just my room modes for help and sealed boxes and such. For the effort and expense that I am going to. I would like to build that low extension and high'ish SPL performance into a small box. The 8" diameter drivers are attractive, but I am prepared to go up to 10" if I can still retain that performance with no larger than 20L net volume for the sub. My test 10" 400wrms DVC version is already here, but I still want a smaller driver than that If I can
Currently, I am using a pair of Logitech Z623 subs at home and also take them away for small parties. It did fine, reinforcing a pair of 15" Samson two ways in an outdoor setting wedding reception. The dance floor stage was a roofed concrete porch, so must have helped a bit, but the bass was present and clear for the party of about 200 folks sitting around. They are only rated 140w each, so I should have an upgrade with the SLS8s, but if I can bag a lot more performance in the package then so much better
Basically main objectives for this project
1 - Music dynamic range performance at home
2 - Home theatre
3 - Takeaway for small parties
Amp is IRS2092 based 500wrms 0.5%THD @4R x 2 with integrated PSU
Smallest form factor vs high output for space available at home and transportation. Aesthetics is also a massive massive priority for me
Below is ZXi8.2, 18L, 34hz port, 500w input
vs
SLC8 10L, 34hz port, 200w input
Dark trace is SLC8. I can draw a pretty line and make a pretty box, but honestly I don't know how to interpret this modelling data to know how much more prodigious clean output will I get with the larger and more expensive ZXi8.2 boxes. Hope I have entered the ZXi8.2 coil data correctly