music frequency

Picking 40Hz means you will loose much of the reproduction of the bottom 7 keys on a piano and organ.

Remember that in general, a speaker that goes to 30Hz at 3db down will reproduce 40Hz notes clearer and more realistically than a speaker that goes to 40Hz at 3 db down.

Zargon...My point is that those seven lowest piano keys rarely get played. A speaker that doesn't try for the lowest frequencies may reproduce higher ones better (not worse as you suggest) because it can use a smaller lighter cone driver, which is not being driven in and out to the ends of its excursion range. If one must compromise, skipping low end extension is a reasonable choice. It depends also on the quality of the bass that is present...is the response smooth or lumpy. The Magnepanar MG1.6 speaker (which I use) quits at 40 Hz, but for most music the bass sounds OK because the response is unusually smooth.

I am not saying that very low frequency capability is worthless: rather I am suggesting that a separate LF driver (called a subwoofer) is better. (That's what I use).

Could not agree more with Eldartford. The same can be said of tuned ports to extend frequency range...often the results are less perfect than can be achieved with a separate dedicated driver (usually from a subwoofer) just for the low end. In the end it is often about compromise. Getting transducers to cover a broader frequency range helps in some sense by eliminating the challenges of cross overs but the downside is that the optimum freq range for that particular driver (size/material) may be exceeded and this usually results in more THD/IMD distortion and significantly less dynamic range.

Discrete transducers appropriately sized for their frequency range and precisely integrated using separate active electronics for each transducer is a solution that some speaker manufacturer's have adopted. A system of this type with large dynamic range and low distortion requires a four way system: subwoofer for 20 to 60 Hz, Woofer for 60 to 400 Hz, Mid range from 400 to 3000 Hz and tweeter from 3K to 20K Hz. The drawback of a system using more transducers and discrete active electronics is higher cost. The advantage is relatively low distortion and high dyanmic range (for a speaker). Nevertheless, harmonic distortion is in the 0.3% range, which is still hundreds of times more distortion than typical digital source and SS circuits.

My comments did not assume a sub, and it didn't sound like Odnok was considering one as well.

Yes, I agree with you there are compromises. One more you didn't mention is that the speaker with the higher cutoff will also probably be more efficient and require less power.

I am using a 4 way speaker (sub built in), where the sub goes to 18Hz. Granted, not a lot going on that low, but it's great to know that if it is present, it will get attended to.

I like this chart from the PSB website. I believe that all frequencies are important. There are orchestra pieces that go down to 16 Hz and some that are only going down to 30 Hz. I believe that there are harmonics above and below the principle tone that are important and anything less is a significant compromise. Add a sub to get that low (integration difficulties assumed).

website:

http://www.psbspeakers.com/audioTopics.php?fpId=8&page_num=1&start=0