JBL 2226H + Fostex FF225K + Beyma CP 21

[Loren42]

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?

Bassbox Pro plots FYI.

Green is the Fostex mid in a .211 cubic foot vented box tuned to 81.24 Hz.

Yellow is the 2226 in a 4.954 cubic foot box tuned to 42 Hz.

Blue is the 2235H tuned to 28 Hz in a 6 cubic foot box just for comparison.

[badman]

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?

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.

Indeed, usually it's done near the crossover frequency, which is pretty easy to achieve when combining these two particular drivers. It simplifies the crossover design by building the compensation in via the sensitivities. It also helps keep system efficiency up.

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.

Big pro 15"s tuned right sound pretty deep. The 10Hz difference isn't a lot, given that they're vented systems and would need a sub for the very bottom content with either driver. Plus, your response comparison gives over an additional foot to the 2235, which could easily extend the 2226 and extra couple Hz, especially if you shifted the tuning a little lower to make a pseudo EBS alignment.

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?

Because an instrument speaker is a very different animal from a controlled midbass like a 2226. They're generally designed to allow breakup and distortion for the sake of 'tone' and high frequency extension, which makes them poorly suited, for the most part, to home hifi. It's a matter of design criteria at the driver level, the 2226 is designed to have low distortion and a flat response curve, which is very much the opposite of most instrument speakers.

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.

Why didn't you bother to check before asking "Why would you use a car driver for home hifi?"

[Loren42]

Why didn't you bother to check before asking "Why would you use a car driver for home hifi?"

Good point. I should have said, "If so, why would you use a car speaker for home HiFi?" My bad.

Tell me how you would do an EBS alignment on the 2226 or 2235? You are not talking about a transmission line are you?

[badman]

Not a transmission line. An EBS alignment is known as an "Extended Bass Shelf". Essentially it trades output above the tuning frequency for a little more extension, tuning the enclosure below the maximally flat tuning, but not so low that it creates a dip. It creates a plateau a couple dB (typically 3) below the reference efficiency. These are often boxes that are 'too big' to allow sufficient gain at a lower frequency to create a shelf without a dip above it. They're not useful for maximum output, but a pair of 2226 shouldn't have any problem with output in a home environment, certainly no moreso than the mid will in this project. Of course, he could just go sealed and EQ them, or use subs. Then the whole point is moot as it'll be rolling off high no matter what higher efficiency driver he uses, as pro drivers are too low Qts for sealed boxes to have any good extension.