[medium jim]

Steve:

You will get more bass once they have broken in, or so I was told by the dealer I heard them at...he said that even when they were tight, they had nice bass, but when they had about 100 hours or so, they really opened up.  Your post is very consistent to what I stated, for HT or really deep bass that a sub would be advised.   

This is were I depart from the theory that to proper integrate them, set the subs or the X/O at 25hz.  This will work if you have a super fast sub, otherwise I suggest to set the X/O at 60-80hz and loss some of the panel bass for the sake of integration.  It seems to work for me, but as Doug S is correct to say, YMMV. 

Then ask yourself this, how many times are you going to be playing music that has information below say 25hz or even 30? 

I think Wendell or Josh would tell you that they weren't designed to shake floors, but to reproduce the lower regions accurately. 

Jim

[josh358]

At the risk of being labeled "one of those", I second Josh's endorsement of EQ.  At least the Behringer DEQ2496, which does everything in the digital regime.  Even if you leave everything above 200 Hz alone, the ability to smooth out bass response in the room is well worth the price of admission.

Off topic, but one "hidden" ability of the DEQ is the stereo width control.  It lets you go between standard stereo to mono in 10 steps, and I find that listening to orchestral works with the control set at 2 or 3 (in other words, almost mono but not quite) gives an uncanny sense of listening close to the rear of the hall, which can be more realistic than standard stereo - at least in my space.

MGbert

That's interesting. I've also heard that you can do a pretty good from-the-balcony stereo with a mono signal if you add some ambiance, since, of course, in the balcony there isn't much angular separation between the instruments.

I wonder if processing to compensate for interaural crosstalk and HRTF would allow you to eliminate the image smear caused by the lateral displacement of the drivers in line source speakers . . .

[josh358]

I don't have a whole heck of a lot of music that goes really low but last night I put on No Pussyfooting by Fripp and Eno just to see.
At the tail end of the first track the floor should vibrate.
It didn't.
The bass will probably open up a bit more as time goes on but I don't think they'll hit that subsonic region.
I'd need to run line out and set the crossover as low as possible or else it'd muck things up.

That could have something to do with the way they couple to the floor and room rather than with bass extension. If the 20.7's are like the 20.1's, they should be good to about 25 Hz, which is plenty low enough to make the floor shake and below almost all fundamentals. Of course, it's also true that you won't get full bass extension until they've broken in, so it could be that.

[josh358]

Then ask yourself this, how many times are you going to be playing music that has information below say 25hz or even 30? 

I think Wendell or Josh would tell you that they weren't designed to shake floors, but to reproduce the lower regions accurately. 

Jim

A few organ recordings aside, the benefit of that low bass seems to be in ambiance and low frequency noises, rather than the fundamentals.

Good point about the design goals. It's easy to make something that shakes the floor, if you just exaggerate the bass. It's also true that the LF response of any speaker varies tremendously with the room and placement, and that line source dipoles interact very differently with rooms than omnis do, so what works for one won't work for another -- they excite fewer room modes, have different combing, and interact differently with the modes -- nodes become antinodes and vice-versa.  Their strong suite is accuracy. They also couple differently with the floor. If the resonant frequency of the upside-down pendulum motion of the speaker frame is subsonic, as I believe it is, they aren't going to impart much energy to the floor through direct physical coupling, because the motion of the diaphragm is essentially parallel to the floor rather than orthonormal. There will be some of course due to standing waves and acoustical coupling, but even the acoustical coupling will be different. Since the floor acts as a sounding board and transmits low frequency energy directly to the body, this could result in an impression of less bass.

[SteveFord]

I have no complaints about the bass extension, I was just pointing out that both Tonepub and MediumJim were right but were looking at the subject from two different angles.

I'll return to that recording in a month or so and see what we've got.
Right now I've got the mother-in-law camped out in the living room so that's the end of that for a bit. 
You have to be nice to the elderly.

Which reminds me, thank god for solid state gear as these women NEVER turn anything off! 

[Toni Rambold]

25 Hz is equivalent to a wavelength of 45'.
Maybe the maximum amplitude is shaking the backyard dunny ... 

[SteveFord]

My toupe' did wind up in the fireplace, I just figured the dog got ahold of it and tried to bury it in the ashes.
Perhaps you're onto something...

[Toni Rambold]

Sound

Wavelength

[SteveFord]

I was only kidding...

[mg3720]

After I had my 20.7’s for two months, I did an Audyssey Pro calibration.  The Pro version allows custom target curves, but I use the default curve.  After the calibration, Audyssey recommended a 40Hz crossover, but I override the setting to full range and continue to run them that way.  Three months later they have developed a really smooth low end response.  Piano, bass guitar and other bass capable instruments sound even more lifelike.  For music listening, I do not use the F112 subs.  The subs are used only for movie watching. 

I agree – it’s a crazy hobby. 

[berni]

Steve, did you get my drawings?

About the bass response from 20.1 or 20.7. they go well down but the only disadvantage is the lack of dynamic, authority and slam.
 This is well known at planars.

[SteveFord]

Yes I did get them, thanks! 
I was writing you and then got called away.

I never expected the 20.7s to be subwoofers. 
Where Eno's synthesizer drops real low the speakers fell silent but I know that there's another 30 seconds worth of material on the album. 
It will be a while before I have any real time on them as the mother-in-law camps out in the dining room so she can watch her spanish soap operas on a laptop in the dining room.
No, I can't ditch her at a dog track. 

[SteveFord]

The women folk are gone today so I can blast some tunes without driving them crazy.
The amount of bass output from these speakers is considerably more than the 3.7s have and it was a bit much.
I anticipate that the bass output will only increase as break in proceeds. 

Here's some cross-polination from The Bass Place:

MediumJim suggested that I post this chart to demonstrate a different way to tame too much bass (as opposed to bass traps):
This chart is for the deHavilland UltraVerve 3 when mated up with VTL 300 DeLuxe monoblocks:

Cap                  100 hz                       50 hz                     30 hz
.01 uf               -4 db                         -8 db                      - 12 db
.02 uf               -1.2 db                      -4 db                       - 7 db
.033 uf              -.07db                      -2 db                       -4 db
.047 uf              -.02 db                     -1 db                       -2 db

This shows the difference from the stock preamp coupling caps which are 1.5 uf.
You can go the opposite way, too, of course.
Calculations courtesy of Kara Chaffee at deHavilland.

I just replaced the .047 caps which worked perfectly with the 3.7s with .033s and it's back to sounding much more like it. 
The sound is know consistent from top to bottom without the speakers overwhelming the room with their bass output.
I was pretty sure the .033s would work and I'm happy to say that is the combo.
Maybe the ladies will take in dinner and a movie...

I promise to keep my fat little fingers to myself now.

[jimdgoulding]

Sound

Wavelength

Toni, hi.  That's a nice system you have there.  Your turntable I take it is newish but your amps and speakers are SOTA from the day.  Harry pearson would be proud.  Happy trails and good listening.

[medium jim]

Steve:

Do you find the 20.7's as easy to drive as the 3.6's? 

Jim

[SteveFord]

I asked Wendell if they were more efficient than the 3.7s but he says that they're not.
They certainly seem louder to me at any given volume setting which has to be due to the larger surface area/increased midrange and bass output.

This was really noticeable when I was trying out different output caps in the preamp - when I had .047s in there I would listen with the volume control set at around 8:00.
I went down to the .033s which was fine and then the volume control was set at around 9:30 or so and then (of course) I had to take everything apart again and put in the .02s.
When I did that I had to crank the volume knob up to 12:00 and it knocked the bass down too much so it was back to the .033s. 
You won't know how something will sound until you try it.
When I expand the living room I'll probably be going right back to the .047s which is where I started from!

I'd say the answer is yes, if you've got enough power for the 3.6/7s you're fine with the 20.7s. 

If Thunderbrick's bird hasn't given him a case of terminal salmonella maybe he can let us know his findings when he went from the 1.7s to the 20.1s?

[medium jim]

Steve:

Great post, I think some read too much into the Db ratings and expect a speaker with a higher Db rating to be louder, but if one compares a small  91db speaker against a large 86db speaker that the less efficient one may actually load the room better and be perceived to be louder.

Jim

[kevin360]

I'd say the answer is yes, if you've got enough power for the 3.6/7s you're fine with the 20.7s. 

I think this statement needs to be qualified a little, because I doubt one would invest in the 20.7s and then redirect the bottom end to a pair of subs. That's precisely what I'm doing with a pair of 3.7s. The result is that I was able to replace a behemoth of an amp with a 150wpc valve amp. The tube amp sounds better, but I doubt it would be up to the challenge of driving my 3.7s full-range. Were I to make the switch to the 20.7s, I'd be in the market for another amp. Of that, I am quite certain.

[medium jim]

I think this statement needs to be qualified a little, because I doubt one would invest in the 20.7s and then redirect the bottom end to a pair of subs. That's precisely what I'm doing with a pair of 3.7s. The result is that I was able to replace a behemoth of an amp with a 150wpc valve amp. The tube amp sounds better, but I doubt it would be up to the challenge of driving my 3.7s full-range. Were I to make the switch to the 20.7s, I'd be in the market for another amp. Of that, I am quite certain.

Kevin:

You might be surprised and I would almost bet that you could live with the 20.7's with a mere 150wpc of tube bliss.  Off the top of my head, I believe the VAC's have 3db of dynamic headroom, so they can hit 300wpc for short bursts.  Then there is the way larger panels will energize the room vs the slightly smaller 3.6's that will compensate nicely.

Jim

[mg3720]

I experimented with my 3.7’s and a pair of McIntosh MC275SE tube amps.  I ran each amp in parallel mode making the output 150 watts each.  They drove them just fine, even beyond my normal listening level.  But, it was not a formal test of ability, just an experiment.  I even tried my 20.7’s full range with the McIntosh amps. I got the amps for my 1.7’s for a dedicated two channel setup.