Augh! I bet they're sounding even more amazing and I'm bummed I wasn't there to listen and assist.
Zilch's AK Design Collaborative - Econowave Speaker
- Thread starter Zilch
- Start date
Augh! I bet they're sounding even more amazing and I'm bummed I wasn't there to listen and assist.
As a start, we generally look to how JBL used a particular woofer in their product(s). In the case of 2214H(-1), two examples come immediately to mind, L100T(3), a tower similar to what you prefer, and 4425, a Studio Monitor with compression driver and horn. Those define a range of known suitable cabinet sizes, and with inquiry, their tunings may also be determined.
http://manuals.harman.com/JBL/HOM/Technical Sheet/L100t3 ts.pdf
http://www.jblproservice.com/pdf/Studio Monitor Series/4425LR.pdf
Jack used his in slightly larger cabinets, upsized Baronets, that he had on hand. To do that, I suspect he modeled them in software such as the free downloadable WinISD or equivalent to determine an appropriate vented alignment. 2214H is by design a vented box driver, and its T/S parameters are in most modeling databases. Though virtually any driver may also be used closed-box, unless the T/S parameters are suited to that alignment, they generally will not produce optimum bass performance.
Kegger
R.I.P. 1/12/1966 - 6/1/2017
Kegger:
Glad to hear you are sorting out the mids.
How did you come to those values?
Rule of thumb? Or some calculator? Or doing the math?
You sure your decimal point is in the right place?
Yah I'm still tweaking/thinking.
But here is the math for a Zobel,
R = 1.25 / x Re
C = Le / R squared
Dave took the readings for the HPM woofer and that's where I started for "test book" values.
Now I'm realizing the Zobel can and was being used as a Frequency shaper as well as impedance.
With a Zobel being used from the calculated values I've now lost bass, or more appropriate gained
frequencies above bass which ends up accomplishing the same thing,
also the HPM woofer reallydoesn't "need" a zobel filter (if it is what the published graph shows anyway) so I'm gonna do some
"altering" and try a larger resistor then what was there and go back to a larger cap but not quite as
large as what was there before to see if I can shape the impeadance a little more proper and get a
bit of the bass back as well. We'll see. :scratch2:
With a Zobel being used from the calculated values I've now lost bass, or more appropriate gained
frequencies above bass which ends up accomplishing the same thing,
doesn't "need" a zobel filter (if it is what the published graph shows anyway) so I'm gonna do some
"altering" and try a larger resistor then what was there and go back to a larger cap but not quite as
large as what was there before to see if I can shape the impeadance a little more proper and get a
bit of the bass back as well. We'll see. :scratch2:
A slightly bigger coil on that woofer (first stage of the LP filter) might be your friend, too. Bigger coil == Lower Q of the lowpass filter == less upper midrange.
Possibly might need a slightly smaller cap (to ground) in that filter, if you wind up significantly changing the coil to larger values. That'll put the "knee" of the curve (rolloff point) back in the right frequency range, but with a lower resonant Q...
Regards,
Gordon.
Kegger
R.I.P. 1/12/1966 - 6/1/2017
Thanks for the suggestions Gordon.
The problem is I'm not wanting to drop off the top end of the woofer further, I'm using a
1.5 mh coil and 8 uf cap, my feeling is if I use a larger coil I won't be able to use a smaller
cap to get my top end back. I think I am pretty close now and just want to attenuate that
upper end of the woofer and not roll it off any earlier. Is there any tricks I may not know of
for accomplishing that?
The zobel seems like a solution that could work here, and if the impedance graph for an
HPM woofer is correct and I use say 12-15ohm resistor and it will attenuate enough then
it looks like it just may work for both impeadance and frequency with a large enough cap?
The problem is I'm not wanting to drop off the top end of the woofer further, I'm using a
1.5 mh coil and 8 uf cap, my feeling is if I use a larger coil I won't be able to use a smaller
cap to get my top end back. I think I am pretty close now and just want to attenuate that
upper end of the woofer and not roll it off any earlier. Is there any tricks I may not know of
for accomplishing that?
The zobel seems like a solution that could work here, and if the impedance graph for an
HPM woofer is correct and I use say 12-15ohm resistor and it will attenuate enough then
it looks like it just may work for both impeadance and frequency with a large enough cap?
jackgiff
Well-Known Member
Hi Sheldon,
Since this thread is about doing it yourself, I didn't just give you all the details about using 2214H's in my EconoWaves. For most guys, searching and discovering is half the fun. But since you are speed limited, let's just cut to the chase.
The cabinet size of 1.6 Cubic feet was in post 594, and concerned a pair of EV Baronet clones that were built a few years ago. They became my next EconoWave project with LE10H woofers. Ignore that value, since the 2214H's were not used in those cabinets.
The 2214H's were used in another pair of EV Baronet clones that were built after the original pairs, and they were built roughly 1.5 times original size. In post 504 I said if my memory was correct, they were about 3 cubic feet in volume. In post 507, the volume was calculated to be roughly 3.18 cubic feet, allowing some fudge factors for various things inside the cabinet. Use that number if you want to duplicate my results.
The cabinets were ported through the front, and were tuned at 38 Hz by two ports 3" in diameter and roughly 6 inches in length. See post 507.
The LE14A and 2214H both liked a low pass frequency of 900 Hz, rather than the 1200 Hz used for most other woofers. For correct crossover values, see post 228, and select the Variant 2. option, which is for the JBL LE14A. Use the values of 2 Mh and 15 Microfarads for the low pass. Use the high pass values as shown on the Crossover option. Also add the two 100 Ohm 20 Watt resistors across the 2214H, as JBL did in the 4425.
When you get your cabinets designed and built, please let us all see some pictures.
jackgiff
Well-Known Member
Zilch has done an Index for this thread.
Just a reminder that Zilch has done an EconoWave Summary on post number 228, which will be of great value to anyone wanting to just "get the facts, please."
If you want to find parts lists, crossover schematics, ETC, see post 228. It is priceless.
In fact, that post is bookmarked on my computer, so I don't forget.
Just a reminder that Zilch has done an EconoWave Summary on post number 228, which will be of great value to anyone wanting to just "get the facts, please."
If you want to find parts lists, crossover schematics, ETC, see post 228. It is priceless.
In fact, that post is bookmarked on my computer, so I don't forget.
wianieq
Well-Known Member
I got the Selenium 210's and the crossover parts will be here on Tuesday, and I ordered the waveguides a week before last Monday and they still haven't went through my credit card yet(They were out.):thumbsdn:
I want to use a pair of Marantz 7 MKII's for the woofer and cabinet, but I don't know the efficiency rating of the Marantz woofer. I know its a long shot, but does anyone have a clue? I could post some pics later if it would help. Since the bass overwelms the top end quite a bit, I'm wondering if they would be higher than 95db. I ordered the regular 8 ohm crossover parts so if the Marantz are no good I have a pair of LA's and NLA's I could try it on.
Any input? Thanks.
I want to use a pair of Marantz 7 MKII's for the woofer and cabinet, but I don't know the efficiency rating of the Marantz woofer. I know its a long shot, but does anyone have a clue? I could post some pics later if it would help. Since the bass overwelms the top end quite a bit, I'm wondering if they would be higher than 95db. I ordered the regular 8 ohm crossover parts so if the Marantz are no good I have a pair of LA's and NLA's I could try it on.
Any input? Thanks.
jackgiff
Well-Known Member
Which set of crossover parts did you buy? There are two available for the HF compensation, but the difference is two resistors and one capacitor are different values.
If you have ordered crossover parts already, just try them and see if the L-Pad falls within range of matching the tweeter to the woofer. If it doesn't, you need to try the other set of resistors and single compensation capacitor. Or ask for help.
Kegger
R.I.P. 1/12/1966 - 6/1/2017
Zobel
I ended up with 12.5 ohms and 32uf, bass is back and frequency response looks good at the xover area.
More listening now.
I ended up with 12.5 ohms and 32uf, bass is back and frequency response looks good at the xover area.
More listening now.
jackgiff
Well-Known Member
If the Marantz woofers are much greater than 95 db, even with the L-Pads at maximum, the woofers will still sound louder than the tweeters. I have a gut feeling that it will be OK. If not, and the tweets are not loud enough, you may need to order the resistors and compensation cap for the "greater than 95 db" one.
Good luck.
Give 'em a little call on Monday to "Expedite."
[There's apparently been an extraordinary demand for these lately....
]
Kegger
R.I.P. 1/12/1966 - 6/1/2017
Dam I hate sibilance, I think these frickin kimber kaps I put in the high pass section are the
culprits as it wasn't there till I decided to "upgrade" the "quality" of caps in the xover since
I had them here. UGHH!!
Just sitting at my pc not even in the same room as the stereo all I could here is SSSS, SSSSS! AAHHHH!!!
-------------
Time to do more digging, may resort to the giant oil caps I've been stashing away, but man there biggins!!!
culprits as it wasn't there till I decided to "upgrade" the "quality" of caps in the xover since
I had them here. UGHH!!
Just sitting at my pc not even in the same room as the stereo all I could here is SSSS, SSSSS! AAHHHH!!!
-------------
Time to do more digging, may resort to the giant oil caps I've been stashing away, but man there biggins!!!
jackgiff
Well-Known Member
:lmao::lmao::lmao:[There's apparently been an extraordinary demand for these lately....
Thankyou Jack and Zilch.
I did find the L110t3 dimensions by scouting the net; by allowing for 3/4 inch thickness I came up with 3.8 cu feet but what totallty confused me was the 1.6 cu feet that Jack had given.
Also in the l100t3 the Xover is 800Hz but this was for L14A. I have not found cabinet insides drawing, in case there is a sealing off of any of the Cabinet, say for the mid driver, so that the woofer sees less than this. Obviosly the guide and drivers and X-overs eat up some of this. It seems that the L100t use 2214 but the L100t3 used L14A.
Zilch thanks for 4425PDF ptr it looks to be close to the Baronets in configuration.
Found volume to be 1.9 cu ft, much smaller that L110t (exactly 1/2). It also has 2 ports like Jacks speakers. the crossover is 1.2kHz.
So it appears the same woofer has 2 extremes in JBL usage.
I did find the L110t3 dimensions by scouting the net; by allowing for 3/4 inch thickness I came up with 3.8 cu feet but what totallty confused me was the 1.6 cu feet that Jack had given.
Also in the l100t3 the Xover is 800Hz but this was for L14A. I have not found cabinet insides drawing, in case there is a sealing off of any of the Cabinet, say for the mid driver, so that the woofer sees less than this. Obviosly the guide and drivers and X-overs eat up some of this. It seems that the L100t use 2214 but the L100t3 used L14A.
Zilch thanks for 4425PDF ptr it looks to be close to the Baronets in configuration.
Found volume to be 1.9 cu ft, much smaller that L110t (exactly 1/2). It also has 2 ports like Jacks speakers. the crossover is 1.2kHz.
So it appears the same woofer has 2 extremes in JBL usage.
dnewma04
The Healer
are you sure it didn't sound more like bow chicka wow wow....ssssss....sssssss....ahhhh!!?
If so, maybe it was coming from your PC.