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Hello,
I have a new project Hi-Fi using JBL 2226H in bass reflex enclosures + midrange + Beyma CP 21/F tweeters with passive crossovers, Fc will be around 400 Hz and 7 kHz.
My question is about the midrange driver. I think that using a Fostex FF 225K full range isn' t a bad idea. Efficiency is 96 db/watt @ 1m.
What do think about this driver? Thanks
http://img148.imageshack.us/img148/5670/ff225k1xi9.jpg
http://img165.imageshack.us/img165/4594/ff225k2gc9.jpg
This is a fantastic driver though level limited. It will give up the ghost before the other two drivers, though not as soon as the miniscule Xmax would indicate (the coil is almost exactly the same height as the gap). Used as a pure mid the way you are, it should be able to give you plenty of output in the home environment but if you ever wanted to get REALLY loud or fill a big space, you might run out of steam.
But, within that limitation, this is one of the great midranges avaialble now. It's got some design bases upon the JBL LE8T (aluminum dustcap, giant motor, plated pole (I believe, in this case... the JBL certainly had it). The extremely low inductance is a very nice benefit and points to a lightweight single-layer coil and a shorting path.
I think the Fostex looks like a very good mid. However, the 2226 has some issues that I don't understand why you would want to use it with the Fostex.
First, the sensitivity of the 2226 is higher than the mid. That is not a good combination if you intend to use a passive crossover. The mid will not have enough SPL to overcome the higher SPL of the 2226. However, the difference is not huge. Still, not a good match. It is better to have a mid with a higher SPL so that you can pad it down to match the woofer.
Second, the Fs for the Fostex is actually lower than the Fs of the 2226! What made you want a cross over at 700 Hz? Ideally, it would be better to get the low end of a 3-way crossover at or below 400 Hz which is outside the human voice range. I don't think the 2226 buys you anything that you can't get with the Fostex in a good vented enclosure. A 2235H may be a different story, but 2226 is not a good choice, in my opinion.
The other problem is the 2226 is an instrument speaker and generally they do not make a good HiFi woofer, if that is your intent.
Personally, I would not use the 2226 for a HiFi woofer. It's Fs is simply too high and there are much better choices out there that will provide better low end response.
I am not familure with the Beyma CP 21. Isn't that a car speaker? Why would you use a car speaker for home HiFi?
If you haven't already invested in the drivers I would say that there are far, far better choices for HiFi than what you have cited that you should look at. Why not give the Seas Excel line a good look? Not cheap, but excellent drivers nonetheless.
Just what type of enclosure do you have in mind? What are your design goals?
I would back up and start with what it is you want to achieve and then select drivers that fit the need based on that.
If you already have a set of 2226s I would consider trading them for something better suited to your needs. I know this is a JBL forum, but it is important to stand back and ask yourself first what it is you intend to create as an end product of your efforts from a high level. Then devolve the design downward from the top level to the low level details. This is a top-down approach and will be your best way to achieve your goals.
Just my thoughts.
Loren
700 Hz? No I wrote Fc = 400 Hz. The Beyma CP 21/F is a good tweeter Pro for high end Hi-Fi. That's a very good compression driver not very expensive
http://profesional.beyma.com/frameset_ingles.php
http://www.toutlehautparleur.com/twe...1f-p-1518.html
According to JBL, it is a "380 mm (15 in) Low Frequency Transducer", and according to a lot of people, it is one of the best low-frequency driver still available. (with his Japanese competitor,TAD TL-1601).Quote:
Originally Posted by Loren42
Bertrand.
At the time I had connection with a Beyma importer, and they are a good 075 replacement. I have thought about getting a pair off 075s but the bids go way over my head. Back in 1986 when I got the CP21 I couldn't hear the difference between them and JBL 075s.Quote:
Originally Posted by Alfa Corse
I use the JBL 2226 myself for audio and find it a very nice sounding driver. I also use a 1.6khz crossover to my Edgarhorn.Quote:
Originally Posted by Loren42
I just thought since you spoke negatively about the 2226 that I should add a positive note to using them.;)
Regards, Ron
It may be a very fine driver, but it is not going to perform as a low frequency HiFi speaker. You need a sub.Quote:
Originally Posted by bstleve
JBL uses two of them in an 8 cubic foot cabinet tuned to 40 Hz. F3 is at 45 Hz. 35 Hz is -10 db down and will trail off at 24 dB per octave beyond that.
That's fine for sound reinforcement, but not really desirable for a home stereo 3-way system.
As an example of what I mean, there is a guy (TLSGuy) on Audioholics that just designed a box for an 8" JL Audio woofer with a Fs of 25.24. Box is a vented enclosure, 2.4 cubic feet, with an Fb of 21 Hz and an F3 of 22.2 Hz.
That's 3 dB down from flat at 22.2 Hz compared to 3 dB down from flat at 45 Hz for the JBL. The JBL is a whole octave higher.
I would not want to use the JL Audio driver to drive a theater or concert, but in a normal house the JL Audio woofer will deliver serious bottom end!
You can use the 2226, but you then need to think about a sub to fill out the lost bottom end. If I had a choice between adding a sub or a 3-way system that already had the extended low end, I would pick the latter because it will almost always sound better and be better phase coherent.
That is why I use the 2235H for my woofer in my 3-ways.
Don't get me wrong. I like JBL drivers and the 2226 is a very fine driver, indeed. However, with the Fs at 40 Hz it is more of a mid bass driver and not a true HiFi woofer.Quote:
Originally Posted by spkrman57
It's not that I am dissing the 2226, but saying that there are better drivers out there for home HiFi woofers in that price class. In particular, the Fostex midrange that the original poster cited has a lower Fs.
The JBL 2226 is one of the best 15" low frequency driver and this diver can work fine in a high end Hi Fi system. 140 liters for the enclosure and 42 Hz tuning frequency is perfect.
Let' s talk about the midrange, do you know an other 8" loudspeaker working good in 400 Hz to 7000 Hz range?
i have a JBL D216 that seems to do this range pretty well...
(in an old Ampex suitcase combo)
pretty old, don't know how available they (or their 'decendents') are...
Well, I've used the 2226 in a few home applications and it is a very capable 15" woofer. This woofer has been used by JBL in cinema applications for years so you can draw some conclusions from that too.
Where to begin.... you're frankly wrong on most everything. First, it's generally considered desirable to have more woofer sensitivity. That allows you to do bafflestep compensation without padding the mid/tweet.Quote:
Originally Posted by Loren42
Second, the 2226 is not an instrument speaker, it's a pro midwoofer. It will give 'thump' better than most other quality drivers, which is desirable both in home and pro settings.
The beyma is a slot tweeter, usually used in pro monitoring and home hifi.
Short version is, you should do your homework better, you gave a long post without even bothering to fact check and were flat out wrong on a couple big points.
How do you do baffle step compensation with a woofer that has a higher SPL than the mid? I would guess that it might be effective if the crossover point was close to the step response?Quote:
Originally Posted by badman
I agree that it might be one tool in the tool box for matching a system, but there are many other tools in the tool box that one would employ, not the least of which is the crossover and there is nothing wrong with padding a midrange (if it isn't excessive). You wouldn't want to pad a woofer for obvious reasons.
In the case cited I also stated that 1 dB isn't that big of a deal. You did not mention that.
I also stated that it was only my opinion that the 2226 was not the best choice if you wanted extended low end. Again, I was only stating my opinion based on the premise that 40 Hz Fs was a little high for low frequency response.
I am fine with a differing opinion on that since personal taste is a freedom of choice.
I did misquote when I stated the 2226 was an instrument speaker. Actually, it is a pro sound speaker, but the semantics are unimportant and why does it even matter to your argument?
Lastly, I asked if the Beyma was used in car audio. That was why I followed the sentence with a question mark. That is different that stating that it was, which I did not.
It's a matter of personal choice and if it fits the need, then go for it.Quote:
Originally Posted by Alfa Corse
Quote:
Originally Posted by Alfa Corse
No! And that is the problem. There are very few quality mid drivers that offer a wide range like that and restricting the group to 8" pretty much eliminates any other potential contenders.
Possibly this driver might work from Seas, but the SPL is too low. You would need two in parallel or go to an active crossover system to match the 2226.
The only other contender that I know about would be the Dynaudio D-76AF. Not easy to find them and they are only a 3" dome. The Dynaudio only goes to 5 kHz anyway, so not good enough. However, it does span the range of the human voice so uyou can get the crossover points outside of that span.