Hey guys...we need a little rallying here... - Page 132

When I tried 475PB it in a SEOS15 setup with XO below 1400Hz I experienced an increasingly stronger sibilant distortion as the XO-frequency was lowered. I simply could not use it with the SEOS15. With DE250 I have never experienced this behaviour.
For the two setups I used linear phase FIR filter with steep crossover slopes.

At the time of the test I had not the possibility of doing proper measurements but I found an interesting test done on various 1" drivers in a 500Hz JMLC profiled horn. These measurements shows that HD increases below 1,3kHz on the 475PB. Without being shure, I have suspected this increase in distortion below 1300Hz and triggering of eventually higher order modes to cause the problems.

http://perso.orange.fr/francis.audio...son_1pouce.pdf

Due to my experimence I have therefore been very reluctant to recommend the 475PB unless crossed over 1500Hz+... IMO it then sounds better than the DE250.

However, if you (or others) have very good results with the 475PB using it in the sub 1500Hz region, it would definitely be very interesting to find out the root cause of the problems I experienced.

I purchased a used pair of 2226H from the bay and paid around $150 back in August, have the prices changed that much? At that time you could pick up a new woofer from places like guitar center with a 20% off sale for roughly $275. Also I vaguely remember the new prices sky rocketing a few months back, but the used market doubled up too?

Actually up to over $500 at PE.

I haven't used a Radian CD actually. I've just compiled a list of generally well-regarded CDs with exit angles that are within the SEOS's designed range. I guess the 475 should be used with caution based on your tests. That is surprising given that Radian suggests use down to 800hz.

My experience is with the DE250 and 4550 in 1" CDs. Those are definitely the safest choices and reasonably priced. Erich's upcoming offerings sound promising too.


I'm pretty sure sales of 2226H and 2242H have minimal impact on the operations of JBL. My guess is that they realized they were basically losing money by selling these and in some cases cannibalizing the sales of their complete speakers.

They can either sell you a 2242H for $900 or a 2242H with box, aka the 4645C for $1400. I'd guess they have no more than $100 in the box.

I know they pretty much stopped selling all of the high end consumer parts because people were building clones for 1/3-1/4 the price. I think they are happy no longer selling 2226's and 2242's which I'm guessing was the intent of the price hikes. I bet they will move to a model where you have to supply a S/N to prove you are buying the part for replacement duty kind of like the QSC horns.

JBL/Harman's real problem is that they have been left for dead on the consumer lo and mid fi.

PM sent to Erich for a pair of 2226J's. Too good to pass up. Heard Will's (Sir Byrd) 2226/DE250 setup the other day at a local AK get together and was duly impressed.

I was surprised with the 475PB myself, but haven't give up finding the reason for the flaw. If I do I will update with a possible workaround for it.
But for now I would also recommend the safe DE250 or 4550

Erich's CDs definitely look promising... especially the BA with its purpose to be used with the larger SEOS.

Where did you find the info re: Erich's CDs? I've searched several places but keep coming up empty.

For whatever reason, the neodynium differential drive replacements for the 2206 and 2226 are priced lower at Parts Express.

On SEOS foum pages and a brief presentation on diyaudio. An introduction can be found on the first post in this thread.

I'm not so sure the 2265HPL and 2262HPL are on par with the old ferrite versions. They would need to be measured. I know Zilch did an Ewave design with the 2262 but his measurements were heavily gated.

I know that JBL still uses the 2226 and 2242 in their TOTL ScreenArray systems. Of course these systems have little concern for the weight savings of the neo diff drive but I'm certain JBL would use them if it meant better performance.

according to Guido Behringer the 951 is a Radian product but for some unknown reason they don't show it on their web page. The 951 is in general a 950 with a throat insert, reducing the phase plug exit from ~1.5" to the 1,4" throat exit. Guido also confirmed that the phase plug is the same as for 950.

Slightly OT: Whats a good price on used good condition JBL 2226H drivers?

No, you cant have mine! haha Id say around 125-150 if you are lucky, usually see them for around 150-200 on fleabay.

Tytte71,
I am using Radian 475PB in QSC horn as part of econowave delite. Zilch's xo is 1500Hz, and I have not heard any untoward distortion. In fact, I ditched the DE250 I had in there originally because it had pretty obvious tonal aberrations on most music, even after break in. I have heard similar thing on other DE250 speakers. I personally couldn't live with the DE250.

The 475PB does require a good amount of break in before it settles into final mood, maybe 100 hours. Also make sure you account for the resonant impedance peak if you are measuring low freqs with a xo filter.

I do hear slight tonal aberrations sometimes with the 475PB in the QSC horn, but it is a plasticky horn-like sound, so I am attributing it to the thin QSC horn until my thicker plastic SEOS12s arrive. It does not occur all the time, only on certain instruments at random times. I might try to damp the QSC horn just to exonerate the 475. I'm doing some outdoor measurements today, so I will try to do a THD measurement of the 475.

I plan to use 475 with a 12" driver (10.25 working diameter) which hits 90 degree directivity at 1330Hz. My raw driver measurement of 475 in QSC horn seems to begin its rolloff at 2kHz. Should it play lower than that before starting to rolloff? I'll have to double check that measurement.

i agree. my only concern is whether they use lossy diaphrams or remain pistonic over the audible range. Maybe we could get a group buy going on some TruExtents for the BAs.

If you're going to go beyond Erich's bargains and on to ebay, why not the more sensible 2206 and half the box size?

There are quite a few right now:

http://www.ebay.com/sch/i.html?_nkw=...at=0&_from=R40

Unusual for a 12" in having -6 dB/45 deg at ~1200 Hz; I like the idea of getting as much of the sound as reasonably possible form the CD.

So far your obeservations and experience correlates perfectly with mine. As I mentioned, the sibilance was present when crossing over lower than 1400Hz. I also prefered 475PB over det DE250 when crossing over 1500Hz+.
...and I never claimed the DE250 to be perfect, which is why I want SEOS for my Radian 951. But the DE250 is IMO a decent reasonable priced wideband performer. If you don't like the DE250, try BMS 4550 which also can be crossed over low (only if you experience the same problems as I with 475).
I do also share your experience with the QSC WG... the harshness or whatever we should call it was gone with the SEOS. I never tried to dampen the QSC plastic and I doubt it will be a revealing experiment.

Regarding the 2k roll-off; what you see is not the actual roll-of, but a non-linear FR with its peak maxima at 2kHz. I believe you also observe a relatively steep increase in output below some ~3-3,5kHz?

I would appreciate to see your measurements and hear your experience when trying it with SEOS12 at lower XO frequency

+1

UPDATE:

About 1.5 weeks ago I was told that customs cleared the stuff and they hoped we'd have everything today.

Turns out US customs cleared everything.......but there were 2 small cartons that didn't have the proper marks from the original order.......or something like that. So we had to contact that manufacturer and get the correct paperwork sent over.

I guess that happened two days ago. Yesterday I got a phone call from US Customs to make sure I am who I say I am......again. I've talked to them about 7 times so far, but each time it's only a couple minutes. Got another call from them today around 2:00 letting me know that everything checked out okay and it is 100% in the clear. I received that invoice with all the customs clearance fees, duty fees, bond fees, handling fees, entry fees, ISF fees....bla bla bla......... $5,344.05.


They've had this container about 1 week longer than expected (not really their fault I guess). They made sure to note:

"Also please note: the last free storage day is Monday 6/04, thank you."


So I'll be rushing to the bank tomorrow to wire the money to them. Not sure how much they charge for storage, and I don't want to find out! DHL now steps in for the DIY community to bring everything here to Cincinnati. My guess is that it will be on the road Monday and here fairly quick after that.




Once this is all said and done, I'll be very relieved and then go into more detail how all of this went. I'm so glad this part of the project is almost done.

I wouldn't hold your breath on that. The Truextents, I believe, are only available in a 4" phragm and only for JBL. It happens to also fit the Radian 950 which uses a JBL sized diaphragm.

BTW, it seems that 18Sound has come out with a 4" Be dome Polymer surround phragm, 1.5" exit driver that appears to be taking dead aim at JBL and TAD. http://www.eighteensound.com/index.a...simple&pid=321

Most of the euro pro sound companies don't mess with 4" diaphragms. I wonder if this is using a Truextent diaphragm from the start. It says polymer surround and Be diaphragm which is what Truextent uses. It also has its binding posts in the typical JBL locations.

I have no idea what the price will be but I bet it will be an awesome performer. If the price is not too bad it could be a real contender for big time DIY projects.

One other thing. I know a Truextent dealer that is competitive in price if anyone is interested.

I have a pair of 950s... they are 2" throats.

That's a lot of fees. It's like that old saturday night live skit where the concierge charges for everything, even talking. Charge! Charge! Charge!


I bet.

Do you know the exit angle of the Beyma CP380m? I am using that with the SEOS 12 in a current build. Am I in the designs range?

Holy carp, that is a lot of $$. Guess that will be about a 25% bump in prices. Remind me not to get into the import business!

I think it is 16'30". I'm finding that for the neo version (CP385ND) so I'm not 100% sure it is the same for the ferrite version. If it is that, it is within the design range IMO. You should be able to contact Beyma to get an answer. If it is off of that by much I'd go with either a DE250 or 4550.


No kidding. Erich should contact Art Vandelay Industries for some guidance.

I already have them. What's the angle of the waveguide?

IIRC ~13deg. Jzagaja can confirm. The DE250 and 4550 are both within a few degrees of that.