Hey!
So I found this driver that is produced here locally in Russia. Manufacturer recommends a vented enclosure for this particular driver, but I am currently trying to find a good candidate for a tapped horn that will go down to about 18-20Hz.
Brian Steele recently produced another of his great spreadsheets that takes the burden of calculating all the parameters for different folds so i decided to simulate this driver in a SPUD like cabinet.
Here are the results of the model that I am getting so far:
Maximum SPL:
Cone excursion at 96W:
Drawing of the fold:
I contacted the manufacturer to ask for semi-inductance parameters which I deducted from the drawing of an impedance curve stating that i was going to build a tapped horn to which manufacturer replied that building a TH alignment is not recommended since the driver doesn't have a strong motor/magnet system, won't be able to push big masses of the air inside the horn path and that those simulations are probably not an accurate reflection of what will be happening in reality.
TS parameters are as follows:
It is a 12" driver rated at 300W.
I was going to use two of such subwoofer (one driver in each) to complement my K-402 synergy horns. X-over at probably 50-60Hz, maybe even less.
Is it a bad idea or worth a try?
I attached hornresp driver and record data in case anyone wants to help me build a better model.
So I found this driver that is produced here locally in Russia. Manufacturer recommends a vented enclosure for this particular driver, but I am currently trying to find a good candidate for a tapped horn that will go down to about 18-20Hz.
Brian Steele recently produced another of his great spreadsheets that takes the burden of calculating all the parameters for different folds so i decided to simulate this driver in a SPUD like cabinet.
Here are the results of the model that I am getting so far:
Maximum SPL:
Cone excursion at 96W:
Drawing of the fold:
I contacted the manufacturer to ask for semi-inductance parameters which I deducted from the drawing of an impedance curve stating that i was going to build a tapped horn to which manufacturer replied that building a TH alignment is not recommended since the driver doesn't have a strong motor/magnet system, won't be able to push big masses of the air inside the horn path and that those simulations are probably not an accurate reflection of what will be happening in reality.
TS parameters are as follows:
It is a 12" driver rated at 300W.
I was going to use two of such subwoofer (one driver in each) to complement my K-402 synergy horns. X-over at probably 50-60Hz, maybe even less.
Is it a bad idea or worth a try?
I attached hornresp driver and record data in case anyone wants to help me build a better model.
The simulation's response does not look like a "bad idea" if the SPL capability in the 30-40 Hz range will be adequate for you. Considering the new Klipsch Jubilee uses only a single bass reflex/horn loaded 12" below a K402 crossed around 350 Hz, 2x12" TH covering 18-60 Hz should be fine, if the drivers are decent, and match the TS parameters you used.
I stopped work on that workbook before fully debugging it, so check everything over very carefully before committing the design to wood L)
Things to look out for are the horn's volume in the sim compared to the net volume of the enclosure, for example (it should always be less, but not a LOT less - within 10% for example).
Also, make sure than add filling to your sim.
And compare what you're getting to other alignments, e.g. a simple vented box, or a series-tuned 6th order BP, or my favourite at the moment - offset-driver TL.
From the specs, the driver looks fine for TH duty IMO.
Things to look out for are the horn's volume in the sim compared to the net volume of the enclosure, for example (it should always be less, but not a LOT less - within 10% for example).
Also, make sure than add filling to your sim.
And compare what you're getting to other alignments, e.g. a simple vented box, or a series-tuned 6th order BP, or my favourite at the moment - offset-driver TL.
From the specs, the driver looks fine for TH duty IMO.
Please pardon my ignorant question, i am just wondering about the purpose of the 18 hz tuning.....
Is it for home cinema application?
Looking at the max spl chart, i wonder if it would be worth investigating a slightly higher tuning between 18-25 hz.
In the current design the excursion limited max spl droops down to 108 dB at 25 hz. It is 7-9 dB below the peak at 18 hz, and the plateau starting at 37-38 Hz. Wouldn't it make more sense to up the tuning a little bit, and sacrifice a couple of dBs of the bottom peak to fill up that valley and gain 3-4 dB across the 20-37 Hz band at max spl?
If done right, the result would be more flat overall max spl, more headroom 20-40 Hz and a negligible shift in f3......
Edit: nice transducer specs btw..... 😃
Is it for home cinema application?
Looking at the max spl chart, i wonder if it would be worth investigating a slightly higher tuning between 18-25 hz.
In the current design the excursion limited max spl droops down to 108 dB at 25 hz. It is 7-9 dB below the peak at 18 hz, and the plateau starting at 37-38 Hz. Wouldn't it make more sense to up the tuning a little bit, and sacrifice a couple of dBs of the bottom peak to fill up that valley and gain 3-4 dB across the 20-37 Hz band at max spl?
If done right, the result would be more flat overall max spl, more headroom 20-40 Hz and a negligible shift in f3......
Edit: nice transducer specs btw..... 😃
True if accurate enough, but the fact that the manufacturer didn't consider it electrically 'strong' enough suggests they're not accurate, but the 'burning' question for me is how semi-inductance dropped Qes, Qts down to 0.19!
Probably manufacturer knows more about the driver than it is present in the official specs 🙂
I have a room with these big speakers that are god to about 30Hz. So building a sub that goes to only about 25Hz is kinda silly, so i wanted even more extensions. It is 50/50 music and home cinema. I was looking for an alternative to TangBand drivers that are used in TH_SPUD, but found out that the driver in question here is capable of similar max SPL, just like a pair of Tang Bands.
Eventually, I plan on building 4 tapped horns and install them in a DBA arrangement, so that longitudal modes are cancelled.
Well, shortening the horn path to about 4,5meters make the graph a bit less spikey:
But it is only 1-1.5dB difference.
Semi inductance params were deducted from the impedance graph supplied in the datasheet. The data was present down to about 20Hz. I had to extrapolate the data down to about 10Hz after digitizing the image to table data. So accuracy of it is questionable.
Another option is to use Alpine SWR-12D2. The response is more spikey, but it is has higher xmax (20mm!?) and similar sensitivity in the band i am interested in (20-60Hz). Spikes in the response can easily be EQed. And TS parameters are more trustworthy. No?
Alpine SWR-12D2 in a 100 X 100Cm SPUD box, XO at 45Hz, subsonic at 16, 41V:
I have a room with these big speakers that are god to about 30Hz. So building a sub that goes to only about 25Hz is kinda silly, so i wanted even more extensions. It is 50/50 music and home cinema. I was looking for an alternative to TangBand drivers that are used in TH_SPUD, but found out that the driver in question here is capable of similar max SPL, just like a pair of Tang Bands.
Eventually, I plan on building 4 tapped horns and install them in a DBA arrangement, so that longitudal modes are cancelled.
Will do, Brian. Thanks for letting me know. SPUD kind of fold is the easiest way to get very low tuning in a box, IMO, that can be used as a raiser in home setting.
Well, shortening the horn path to about 4,5meters make the graph a bit less spikey:
But it is only 1-1.5dB difference.
Semi inductance params were deducted from the impedance graph supplied in the datasheet. The data was present down to about 20Hz. I had to extrapolate the data down to about 10Hz after digitizing the image to table data. So accuracy of it is questionable.
Another option is to use Alpine SWR-12D2. The response is more spikey, but it is has higher xmax (20mm!?) and similar sensitivity in the band i am interested in (20-60Hz). Spikes in the response can easily be EQed. And TS parameters are more trustworthy. No?
Alpine SWR-12D2 in a 100 X 100Cm SPUD box, XO at 45Hz, subsonic at 16, 41V:
Guess I'll have to learn about it as it apparently didn't exist back in my active DIY days, though did read somewhere recently that < ~3 mH wasn't enough of an issue, so with this being at the outer limits of drivers I was exposed to..........
Indeed, I assume you're aware of DSL's bigger 'Super Spud' [DTS 10] that was a kit at one time and some folks used the Alpine driver for reasons I no longer remember (higher power handling?) and AVS apparently no longer has a thread search to find it: https://www.avsforum.com/threads/danley-dts-10-super-spud-diy-kit.1189404/
As for spiking, HR has no inherent acoustic damping considerations, so much more muted if you compare to actual measurements and IIRC there's been some actual T/S measurements posted online.