Curiosity regarding Yamaha bass management (1 Viewer)

[Martin Rendall]

Interesting little curiosity. I wonder if anybody can comment on this...

Equipment: Yamaha RX-V1000, Paradigm Studio 100's, and Energy 8" sub.

This question is specific to two channel listening only. That is, in "Effect off" mode.

I've tried various settings for Mains (Large/Small), and LFE/Bass Out" to see what I like the best. I've noticed something which I can't readily explain. I would expect these two settings to sound the same:

Mains - Large

Bass Out - Both (1)

and

Mains - Small

Bass Out - Both (2)

But in fact, they sound slightly different.

Specifically, (1) sounds stronger in the lower midrange (or upper bass) than (2). Why would this be??

I'm hypothesing that in (2) the receiver is sending half the power of the bass frequencies to the mains, and half to the sub, but the sub is failing to fully reproduce the higher frequencies it sees, leaving a "half power hole". But in the case of (1), it sends the full bass power to the mains, and then augments it with more to the sub, so I don't perceive the hole - just better low end bass. Thoughts?

Martin.

 

[Danny Owens]

I have noticed precisly the same thing with my RX-V1. I am using:

Yamaha RX-V1

JBL S-312 fronts

JBL S-center

JBL S-38 Surrounds

JBL S-38 Front Effects

2 JBL S-38's Rear Center

2 Polk Audio PSW 650 subwoofers (2- right and left)

I keep my system at Mains Large and Sub to Both. Even with all these speakers, it is still hollow with speakers set to small.

 

[DonnyD]

Danny, I bet your system is really great. My brother has a pair of the S38 JBL and they sound really good.

I watched some cable yesterday on my system and messed with settings a bit changing speakers from large to small and messing with the sub, etc.

My System:

RX-V1

JBL L100 mains

S-Center

N-28 rears

JBL Sat 2 front effects

Norh 4.1 Prism rear center

SVS 20-39PC sub

On one source, I found that "effect off" sounded really good and then started messing with a lot of settings on my RX-V1. Damn, I was sounding great and very powerful regardless of large or small or sub to both or SW. I detected very little difference in the two and not enough to say which was the best. That being said, those old L100's have kicked the crap outta everything I have lined them up against. Very strong mids and highs with a huge bottom end too.

Have you got into the set mode and messed with your eq any? Some dsp modes change those around a bit.

I have found that the RX-V1 does do some things differently and better than the 2095 Yam it replaced in my system but it takes a lot more tinkering.

BTW: I'm sure you noticed the Norh 4.1 for my rear center. I switched it back and forth with my S center up front and they are very different.... The S Center is more efficient and is louder at a given volume... to calibrate it to the mains, I turn it down to -3db or -4db. It is a very good center with no weaknesses I detect. The Norh Prism center is probably less efficient at this point and I run it at 0db to +2db. You definitely hear a brighter tweet and a little more low end but so far the midrange is not there. They are not broken in yet though and I expect it to change. I have some other Norh products on order to do the HT duties (that is if they are better) while I leave the old L100 as music or two channel duties.

 

[Danny Owens]

Donny,

I didn't think of the eq in the Yammie. I run some Behringer 31 band eq's on all six channels so I just leave the Yammi's eq's flat.

I'll tell you what, those L100's are worth their weight in gold, IMO. A friend of mine agreed to sell me a pair he has had in storage for a few years (dosen't know what he's missing). We haven't agreed on a price.

As far as the bass management goes, if you happen to remember what you did to beef up the mid range when the speakers are set to small, I would certainly like to know. Even though my speakers can handle it, I would like to route all the sub freq's to the subs and get rid of some phase problems that I have between the mains and sub at their common freq's. I have tweeked the subs using a Behringer Feedback Destroyer but I had to gain up a few points to over drive the mains at the problem points. It is definatly not the right way to do it, but it works and the subs don't bottom out.

One other thing that I found out. I watch a lot of DVD concert videos and found the the RX-V1 sound a hell of a lot better with the center channel turned off and run with the phantom center. With movies, I leave it on.

Danny

 

[DonnyD]

Yeah Danny, those L100's are simply a great piece of work and seldom do you find anything that will compare with them. I take it that you haven't got your hands on them yet?

Hope they are ok but at their age, you can expect the foam around the tweets to be gone. I finally and reluctantly changed out the tweets to a titanium model last year and it helped the imaging a bit. I had contacted the JBL vintage division but they had no replacement foams for the tweets even though the tweets were still good. Another suggested upgrade was to put in a crossover but I forget the model of it and never pursued it.

BTW: I bought mine new in 1978 in Athens, Ga. I think I had the first review on audioreview for these old monsters!

I still have my original frames for the grills but had to replace the foam on the grill itself due to age. Found the replacement foam at Radio Shack a few years ago and it matches the original perfectly.

The american black walnut cabs are still in great shape even though they were dragged all over the southeast. I've kept mine looking good with Gillespies wood finish.

In the past few years, I have bought and a/b'ed the L100's with Monitor Audio, Energy, Magnepan, and a few others but the L100's still stood out head and shoulders above the rest IMHO. In any event, the others came and went and the old L's are still here. I do not expect the Norhs to be even close in strength but perhaps will be a little better imaging. Maybe not..... with the L100's track record, who knows? LOL

I too watch a lot of concert dvds and mess around with the dsps to get a better sound. On some, as you pointed out, turning the center off helps a lot. When you hook up the L100's, try them in 2 channel mode on some convert dvds and listen at them shine!

 

[Martin Rendall]

A bit more investigation. Consider (again, for two channel only):

Mains - Large

Bass Out - SWFR (3)

and

Mains - large

Bass Out - MAIN (4)

(3) and (4) don't sound the same. Specifically, (3) leaves a hole in the upper bass/lower midrange. neither choice should actually involve the subwoofer, since the mains are large. So why would this be?? I'm beginning to suspect it's a flaw with Yamaha's bass management.

Matthew,

Would you care to try this test out? You may be surprised...

Martin.

 

[Jim_Stu]

Me too! I think the problem is the excellent quality

of the JBL main speakers.

With my HTR-5280, setting the mains (N38s) to large

sounds better than small. I think the N38s handle

40Hz - 80Hz better than the sub (PB10)! However, it is

a 'bottom firing' sub setting on thick carpet. Therefore, its handicapped.

JRS

 

[Martin Rendall]

Matthew,

Intestesting that you notice no difference between (3) and (4). I totally agree that there shouldn't be one - yet for me, there is! So to recap, with the mains to large, it reasonably shouldn't matter what the LFE/Bass is set to... but I notice a difference (above 90Hz) on my system. I'm not claiming that the sub is on. The difference is in the mains, above 90Hz.

And this effect seems to carry through in the slightly more complex case of (1) and (2) [although I believe that you can reduce (1) and (2) to (3) and (4) with some careful reasoning.

Also, for (1) and (2), with an SPL meter and some careful listening, I've confirmed that setting "Both" does send the bass to both the mains and the sub.

Oh well. I guess I'll just make sure to keep my mains on Large for critical two channel listening.

Thanks,

Martin.