Two-way no compromise on size..

[Juhazi]

AStroop has set exceptional outlines, really - big ones, 2-way, classic/acoustic, moderate bass and spl.

If we do a two-way that goes flat to 35 in a room and sounds good (minimal distortion) we need large drivers. Large midbass starts to boom early so we need a tweeter that can do from 800 up and with low distortion. We are facing a challenging task.

I am perfectly happy with my MarkK ER18DXT low-tuned. They have good output from 35Hz up and decent power response. But they are not big.

For a big 2-way I fancy Gedlee Summa and clones. Some of then have been presented here, and two more. The power response and horizontal radiaton are well controlled and the bass is 15"
- gainphile's S15 Gainphile: S15 - Econowave DSP (dsp)
- HM100 Hifitalo Verkkokauppa - HM-100dB/W (passive)

[LineSource]

"I see no advantage to a horn at LFs. It’s a very poor use of space. Better is just a bunch of closed box monopoles placed about the room.

Horns to me are strictly for the control of directivity and have no real advantages besides that. So they don't make much sense until one reaches the frequency at which they can be effective at directivity control - this is strictly dependent on size you can live with.

Even Don Keele noted some decades ago that horns were a bad choice at LFs when volume and complexity of the enclosure were taken into account. Above 500-1k Hz waveguides are essential for directivity control, but below that they work poorly and are not a good choice. Below 200 Hz in a small room, multiple subs are just about the only choice." Earl Geddes GedLee LLC


A review of the SPL vs. Freq curve for the Jubilee Corner Horn Woofer helps support Dr. Geddes work on multiple sealed woofer room swarms. A sealed or ported woofer also gets the ~5db corner gain and 90 degree controlled directivity. Sealed woofers make sense if digital room equalization and/or digital Xovers are used. A Grand Piano’s low A 27.5Hz is easy to reproduce with low phase shift using a sealed woofer.

Personally, I favor the vocal weight and uniformity from using a 10" midbass over the 100-1200Hz vocal range before going to a 1" SEOS waveguide that reaches to 20Khz. JBL enjoyed decades of success with (18"+10"+horn) studio monitors. Even Mark Levinson's statement speaker the Daniel Hertz M1 uses a cone(12") midbass.

[PeteMcK]

re: "ER18DXT low-tuned. They have good output from 35Hz" - hmmm, we must have a different definition of 'good output', I found my ER18s lacking when low tuned, The CA18RLYs are much better, even though they require a large box.
Part of the challenge here to me seems to be be to go for an older-school approach, where the box is large relative to the speaker size, 2x CA18RLYs would satisfy that...

[tomtom]

just copy and maybe improve JBL Professional :: Recording & Broadcast :: M2 Master Reference Monitor. As improvement i would make it bigger so WG can go lower and there will be place for smooth WG to baffle transtion. This is current SOTA. You dont invent anything better. Also if possible use D2 driver, there isnt better compression driver. If you want big experiment you can make bass response cardiod /leaky enclosure/ and control response even lower. But it want be easy.

[AStroop]

That M2 is a beautiful thing!

Indeed one of the original ideas I had was to do a couple of big sealed bass bins with an 18 in each or a couple of 12's and then have a couple of horns or seos 18's from 600Hz up.. the thing is I have a large room, multiple subs might more difficult to integrate.

Will keep it on the table and do some more searches, while looking over the Jubilee plans. A sealed cab or pretty much ANY cab is easier to build and I guess should be considered right up until I have done the buying....

I really appreciate the feedback and experience.

Cheers
A

[tomtom]

I read whole thread just now. Beyond the Ariel is my system. I try to listen at realistic level /it is not all that loud/ - mainly classical and jazz. The room is 7,5x6,5x3m. Honestly with room as big as yours, the bass problem start so low that i dont see need for multisub. In my room any there isnt any problem til ca. 60hz. In yours it will be ca. 45hz. It is not worth to do multisub. Im rational man - no subjectivist at all but multisub solution has its own set of problems /and also EQ at bass/ and not many people talking about it. I believe that in smaler rooms its only way to do good bass but if you room is trouble free to ca. 60hz it is better to leave it conventional stereo and anechoic flat /no in room flat/. I try to EQ my system at listening position to about 100hz /to eq modes/ and it always mess up localization. I use very simple 2 mic double bass recording to evaluate this. The efect of eq was that sometimes there was bass sound right from speaker /IMO when recording hit EQ spot/ and not from fantom spot where it should be. My speaker are capable of rock solid fantom image and they are absolut indetectable as source of sound so i can clearly hear such effect. Nobody also talk about reasonable way to sum stereo to mono sub signal. What if bass signal on recording has oposite phase you end up with no bass at all. Do you think that same thing happend in room in acoustic domain?

I agree that we need extension to 20hz /and reasonable roll off after/
You dont hear it, is is more like feel something very physical - you feel when choir stand up just before FF as conductor prepare them. It add great deal of realism. Unfortunately not many recording has this subsonic info and many cardiod mikes hasnt subsonic extension /also they tend to use subsonic filter/

My humble suggestion:

Build something like M2 /when you cannot use D2 driver use BMS coax instead/ And make some nearfield stereo subs <50hz very steep XO.

Place everything symetricaly in room.

Also use digital XO. It is not possible to integrate such a system without DSP XO with delay etc...

[Coytee]

Originally Posted by AStroop

Will keep it on the table and do some more searches, while looking over the Jubilee plans.

Here's how they're currently building them. Roy (co-designer) wanted to make it an easier and stronger build. The box itself is essentially the same with the big difference being the "shelves" instead of braces on the inside of the bin.