Demise of bass quality in Main speakers


When I was shopping for new speakers in addition it became quite clear that modern day main speakers are being made with smaller bass drivers. And to get larger bass drivers you have to go up to alot more expensive models and still they or on the small side.

The Industry came up with a solution for bass challenged main speakers - buy two subwoofers to solve the problems of the modern age main speaker. And subwoofers now being sold in pairs have 8 inch or 10 inch driver sizes, which are still not big enough unless you spend a lot more money.

I bought a subwoofer with a 12 inch driver 20 years ago, thankfully. When I looked at the newer subwoofers the speaker manufacturer told me that he gets many comments stating that the fullness and rumble ability of modern day subwoofers have been substantially diminished, and he agreed. Isn’t this what subwoofers are all about. Why would I need a subwoofer for better define the lower base area. Fortunately I bought very nice main speakers which had a range spec down to 20 Hz and the bass driver size is 8 inches but I had to pay more to get this larger size.

Why do people put up with this? Put larger bass drivers in Main speakers and then you won’t have as many people complaining about Poor bass quality. Doesn’t this make sense?

emergingsoul

I have always felt that, ‘there is no replacement for displacement’ such that the larger the woofer, the better the bass. But I recently read an account by Roger Russell of McIntosh who, in consulting Rudy Bozak and others designed a two-piece speaker (McIntosh XRT-20) that included a 24-tweeter column and a dual 12” woofer (in a separate cabinet). Further experimentation led him to drop the woofer and stick with just the column of tweeters, focusing on the characteristics of the drivers and their ability, like pistons, to drive the bass. By careful arrangement in the column, he was able to produce magnificent bass without the use of a big (woofer) driver. He has a website that details his experiments, experiences, and the results. From what I see in the market, McIntosh has continued his contributions, and Tekton may have improved upon them.

My main Tower speakers have built in sub woofers and the speakers are 8 inches wide, and they also have gain control I also have two sub woofers with DSP I've used REW to dial everything in and I must say, the sound stage, inner detail, dynamics no matter what music I'm listening is absolutely captivating  From single female voice only to Daft Punk 

To reproduce the bottom octave accurately and musically is expensive and can be difficult in a bad room. If it's an audio only system I would opt for a 12" or 15" sealed, self powered sub like an Hsu, ULS-15 MK2 Subwoofer and two is always better than one to even the bass out in the room. Anything smaller IMO is a bass module, not a true sub-woofer. 

I have had Avangarde Duos since 2006-7, and only I after I added a pair of 15 inch subs, with DSP, changed to a big Koetso stone, and fully isolated the table with the biggest Minus K did I achieve bass that matched the quality of the midrange- horns runs straight from Lamm ML2s without a crossover.

@ghdprentice     You are certainly correct in saying that bass speaker engineering has improved greatly in the last 20 or 30 years.  But that would be a reason for building larger bass speakers, not smaller.

In principle, leaving aside engineering issues, a big unit will deliver more bass than a smaller one.  This is why in earlier times 12 inch units were commonplace although as you say 'boomy' - read 'distorted'.

But there are engineering reasons why two smaller bass drivers work better than one big one.  I bought KEF 801s when they were launched.  These had a single bass driver of 15 inches.  But a few years after KEF launched the 802 with two 12 inch units and not so long after that they discontinued the 801.

As you say, to obtain quality bass you need high driver throw, speed and accuracy.  This is mainly achieved by minimising the mass of the cone and other moving parts whilst maximising its stiffness.  This latter is crucial as flexure will create distortion,  It is axiomatic that, all other things being equal, this is more easily achieved in a smaller diameter unit.  Indeed I suspect the flexure of the cone increases as the square of its diameter.

By the way, you say your 8 inch units 'go down' to 24Hz.  But what is the output down there relative to the mid-range?  I'll warrant it's at least 10dB down.