Why do most home 2 way systems have 6.5" woofer?

[jcebedo11]

Why not use a bigger woofer just like professional cinema/concert speakers. If you go to JBL site, they even have two way speakers that have 15"!! woofers/midrange. A lot of cinemas probably use these speakers and I don't hear any dispersion problems. Larger woofers can be of higher sensitivity and lower distortion. I have owned 2 ways that vary between 6.5" and 8" woofers. For example Dynaudio Contour 1.3 vs Mackie HR824. I actually prefer the sound of the Mackie which has a larger 8" woofer/mid. I don't really hear any midrange advantage of the Dynaudio. Maybe I just dont have golden ears like some people.

 

[sergeauckland]

Possibly because most people then wouldn't buy them as their partners would object.

S.

 

[Lorenzo74]

Why not use a bigger woofer just like professional cinema/concert speakers. If you go to JBL site, they even have two way speakers that have 15"!! woofers/midrange. A lot of cinemas probably use these speakers and I don't hear any dispersion problems. Larger woofers can be of higher sensitivity and lower distortion. I have owned 2 ways that vary between 6.5" and 8" woofers. For example Dynaudio Contour 1.3 vs Mackie HR824. I actually prefer the sound of the Mackie which has a larger 8" woofer/mid. I don't really hear any midrange advantage of the Dynaudio. Maybe I just dont have golden ears like some people.

Check waterfall and resonances, it’s not only a matter of dispersion. If you have a 2way with 8inch you have to cross very low (<1.5kHz..?) for the reason above. The. You need a pretty good waveguide (not trivial) and a good 1inch tweeter capable to play low. Also you need big (expensive) inductors and caps on both drivers.
So if you don’t need high SPL, not necessary at the bottom of audio-band, there is actually no advantages to gor for >6.5” in a bookshelf speaker.
On the contrary, when High SPL is needed, check PA speakers, 8inch and waveguide tweeter is the standard.
hope this helped
Best

 

[Mimeyar]

Bigger woofers are more expensive. Larger speakers are more expensive to produce and ship so bookshelf speakers have a price advantage. The audiophile market prefers tall and slim over wide in terms of appearance. Thin speakers are easier to place into small gaps and most of these speakers will be going into corners of bad rooms.

So professional speakers tend to be wide with large woofers and audiophile speakers tend to be tall and slim with multiple smaller woofers in a vertical array.

 

[Wayne A. Pflughaupt]

My understanding is, with larger woofers the upper frequencies (mids) don’t disperse well but tend to “beam.”

As a result, a larger woofer in a 2-way requires the high freq driver to operate down to a lower frequency. With most 6-1/2” two-ways, the tweeter crosses over in the 3-4 kHz range. By comparison, those 15” JBLs you’re talking about, the compression drivers in speakers of that type typically operate down to 1.5 or even 1 kHz.

Requiring the high freq driver to operate to a low frequency means it must be able to handle a lot of power. Thus, look at the size of the magnet for a typical compression driver.

With the Mackie HR824 speaker, the tweeter operates down to 1.9 kHz. As you can see here, that tweeter also has a large, heavy-duty magnet.

Back in the mid-to-late 1980s, a speaker company called Genesis Physics offered two-way speakers with 8” and even 10” woofers. Their tweeters operated down to 1.5 kHz, and once again, you can see that their magnets are huge.

Of course, that doesn’t necessarily explain why you don’t see more home speakers with 8” woofers. Obviously it can be done. My guess is that the tweeters they require are an added expense that the manufacturers can’t justify, as it’s not hard to design a speaker with a 6-1/2” woofer that can get as low as an 8” woofer, or close enough to it.

Regards,
Wayne A. Pflughaupt

 

[AnalogSteph]

A 6.5" / 1" two-way with bass reflex historically proved to be a decent compromise between level handling (bigger = better), driver dispersion matching (smaller = better) as well as complexity, size and cost in typical hi-fi use.

Combining an 8" + 1" traditionally would not have been a good idea as it would have been nigh impossible to cross them over in a sensible manner (basically by the point dispersion is halfway even, the tweeter is crossed awfully low and will start to distort rather too much). This combination only became viable at all through the use of waveguides for the tweeter, at which point I would not be surprised if evenness of dispersion actually beat the non-waveguide 6.5" / 1 " combo in the Dynaudios. Comparing these two basically is apples and oranges.

The biggest woofers I've seen in a 2-way with dome tweeter would have to be 10", e.g. Genelec 1032C. This is entirely possible with a waveguide, but dispersion does narrow a fair bit as a result, and wider dispersion is traditionally preferred in hi-fi speakers (for ease of positioning, I guess). It is generally more advantageous to be going with a 3-way design at this point, not the least due to reduced midrange distortion - 2-ways tend to peak right around where our hearing is most sensitive.

Hi-fi speakers tend to prioritize quality over quantity of sound. PA is a different world, where large high-efficiency drivers and the idiosyncrasies of horns are worth putting up with in the interest of higher output levels.

 

[EJ3]

A 6.5" / 1" two-way with bass reflex historically proved to be a decent compromise between level handling (bigger = better), driver dispersion matching (smaller = better) as well as complexity, size and cost in typical hi-fi use.

Combining an 8" + 1" traditionally would not have been a good idea as it would have been nigh impossible to cross them over in a sensible manner (basically by the point dispersion is halfway even, the tweeter is crossed awfully low and will start to distort rather too much). This combination only became viable at all through the use of waveguides for the tweeter, at which point I would not be surprised if evenness of dispersion actually beat the non-waveguide 6.5" / 1 " combo in the Dynaudios. Comparing these two basically is apples and oranges.

The biggest woofers I've seen in a 2-way with dome tweeter would have to be 10", e.g. Genelec 1032C. This is entirely possible with a waveguide, but dispersion does narrow a fair bit as a result, and wider dispersion is traditionally preferred in hi-fi speakers (for ease of positioning, I guess). It is generally more advantageous to be going with a 3-way design at this point, not the least due to reduced midrange distortion - 2-ways tend to peak right around where our hearing is most sensitive.

Hi-fi speakers tend to prioritize quality over quantity of sound. PA is a different world, where large high-efficiency drivers and the idiosyncrasies of horns are worth putting up with in the interest of higher output levels.

Your 3rd paragraph seems to indicate that a good 8" design is the point that is better than the expense to do a good 10" design (due to a good three-way being a possibly better design for the money). To me that indicates differently than your second paragraph, that a 6.5 is optimum. It seems to me that a good 8" design would be optimum. I have never had the significant other have any more of an issue with that size than with 6.5" designs (it's the same-they are all too big). But, when done right, I feel that the 8" two-way has the potential to have the best balance of response, imaging and economy (of both space & price). However the concentration of research seems to have made the 8" the void, so very few (if any) have been done right.