OK, this is probably going to get the same response as my first question about break-in, but...

When I was running a stereo system with M2s and a PSB 6i sub, I tried running with the sub's high pass filter wired between pre-out and amp-in on the receiver. Helped a lot when playing at higher volumes, but I really thought it hurt the imaging noticeably. Not terrible, but not as good as when I had the M2s playing full range.

I wrote it off as a side-effect of having a 12 db/8va passive high pass filter vs. a 24 db/8va active low pass filter in the sub, switched back to full-range on the M2s, then got inspired one night and ordered M60s. Full range, no problem.

Fast forward to the present. Shiny new HK AV receiver with lots of good DSP bits inside. Hook up the M60s, set them to "small" with the sub taking the overflow. Initial default was 100hz cutoff -- didn't like that so much, so split the crossovers and went to 60hz on the mains, 80 hz on the surrounds -- definitely sounded more like I remembered the M60s sounding on the stereo hookup.

I was playing around with the crossover some more tonight, and tried setting the mains back to "large". Holy &%^*, the nice sharp imaging came back (I was playing music at the time). Didn't sound too bad on a couple of DVDs either.

So, here's the question. For you people who run a mix of HT and music, how are you setting the mains ? Small or large ? Does anyone else find that running the mains through the crossover hurts the imaging, or is it just me ?

I don't understand how an LF crossover can really affect imaging, which I *thought* happened mostly up in the KHz range... any ideas ?

Thanks,
JB

P.S. There's that song on the radio again -- "Amazing Grace" sung to the tune of "House of the Rising Sun". What's that all about ?

John, I'm also puzzled by what you report. My understanding is also that imaging depends on midrange and upper frequencies and that strengthening response in the mains below 80Hz or so by setting them large can't affect it significantly since those frequencies are essentially omni-directional. Theory aside, in a system where I use a sub I always set all speakers "small" and it sounds a bit better(no change in imaging, however).

OK, found the first clue. The receiver UI seems to include quite a bit of "if you set this then I automatically change these other settings" logic. I was running in "surround off" mode, which by default bypasses all the DSP processing. If the mains are switched from "Large" to "Small" then the surround mode is switched from "Surround Off" to "Surround Off + DSP", ie the signal starts going through the DSP in order to perform bass management.

Damn computers, I just can't get away from them.

I still wouldn't expect this to make much difference because I was playing the CDs on my DVD player through a coax digital feed so the only effect on the mains content should be the DSP's implementation of the 60 hz high-pass filter which I would expect to be negligible at the frequencies which matter to imaging.

Then again maybe years of abuse have rendered my ears incapable of hearing anything above 80 hz and so I'm getting all my imaging cues from the really LF stuff

One important point is that the better imaging in "Large" only applies when I'm playing in two-channel mode. Once I kick in a surround mode that extends the stereo content out to the surrounds (PL-II, Logic7 or Neo6) the difference between Small and Large is not really noticeable.

In reply to:

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P.S. There's that song on the radio again -- "Amazing Grace" sung to the tune of "House of the Rising Sun". What's that all about?

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Isn't it great? The group that sings that one is The Blind Boys of Alabama. I had the great fortune of seeing them live as surprise guests at a Ben Harper show I saw at the Greek Theater in Berkeley a couple years ago. I highly recommend them if you're into that style of music.

Oh my gosh...this is weird. I've owned my HK 630 for several months now and I just went back to do some large/small testing. The results were shocking! I didn't really do "stereo" testing. Mostly movie tests. 5.1 and 7.1 tests. Okay...bizarro but true. I tested the other night doing tons of A/B stuff with small vs. large. For the most part I focused on the center channel signal.
The test material was Lord of the Rings: Fellowship EE set to DTS-ES Discrete played in 7.1.

For a long time I had my center channel set to 80 Hz. I found that the sound was clear when set to this. But you know, the Axiom VP150 can go lower than 80 Hz...so I thought I'd test it at 60 Hz. My M60s (front mains) were set to 60 Hz...so why not balance the front end Hz cut-off. Seemed to make sense to me. Well...needless to say, the sound DID indeed change. The sound was a little fuller...on the low end. But again, we're talking dialoug...not something that should really be heard in the 60-80 Hz range. What took me a while to catch on to was that when I changed the crossover from 80 Hz to 60 Hz, for some odd reason, the high end of voices were getting cut off. Now, I don't know what the Hz range was...but it was well high enough that going deeper shouldn't change anything. So that's when I said...let's try large. Let's hear what an "untampered" signal sounds like. Whoa...not a huge change...but when you're being maticulous...it's a huge change.

There was just more subtle detail I was hearing in peoples voices. It was as it all should be heard. I tested these sounds with four peoples voices in the movie just to be certain. Bilbo, Gandalf, Galadrial, and Frodo. All utilizing different spectrums of sound. Each one had just a little bit more clarity and soundscape when set to large. Untampered. Now...needless to say this is depressing because my final analysis is that my receiver is compressing the sound in order to run it through the crossover. I'm obviously approaching this from a very analytical standpoint, but I feel when you spend thousands of dollars...you want to get the most of out of that investment.

Now, one might read this and say...if you like the large setting so much, just use that. Ahh...that's the biggest downfall. If you have all speakers set to large it considerably cuts down on subwoofer activity, which is very exciting in movies such as LOTR. So, it's a lose-lose situation, though setting the speakers to small is the best compromise as you get "most" of the sound out your main speakers and much more activity out of your subwoofer. But, compromise just doesn't sit well with me.

Harman Kardon definitly lost points with me when I found this out. I did everything I could think of even down to a factory reset (reboot). Same results.
So, what's my conclusion? I'm receiver shopping. Currently looking at the Denon 3805. Looking for a receiver that won't "mess" with the sound.

Sad It's a sexy looking receiver if anything, but not a pure one.

Don't be too quick to dump on the receiver... I believe I saw exactly the same issue when I was running through the analog high-pass filter in my subwoofer.

I have never heard any specific criticism of the HK signal processing; if anything the HK bass management is felt to be very flexible and to have high sound quality.

We should both try to run the same tests with a competitive receiver before we start thinking bad of HK... right now there is no reason to believe a Denon etc... would be any different. I'm not saying I have another explanation but I don't think we should blame the receivers too quickly.

Then again if you had posted this *before* I picked up my 630 I guess I would have said "yes, dump that piece of junk before it messes up your system any more... and sell it to me"

H/K 525...I have my M50s set to Large with sub for music, and small with a 60 hz cross to the sub for TiVo/movies. I've got QS4s for surrounds, so I set those and the nonexistant center (well, the TV speakers) to cross at 100 Hz. The funny thing with the H/K is that you have to set a subwoofer crossover, too, if you set the bass manager to independant (by input). I had mine set to 60 Hz, from when I just had the 50s. I realized that when I was recalibrating today, and I set it up to 100. Dialog's significantly better now. I think the way it's set up is the sub's crossover setting on the receiver is the maximum cutoff for the sub, so sounds below 60 from the fronts get sent over, and sounds below 100 for the center/surround get sent over. It's very confusing, and not well documented at all.

>>The funny thing with the H/K is that you have to set a subwoofer crossover, too, if you set the bass manager to independant (by input). I had mine set to 60 Hz, from when I just had the 50s. I realized that when I was recalibrating today, and I set it up to 100.

Ahh, that's what "independent" means. I had initially assumed it meant "independent crossover fequencies", realized that wasn't right, but hadn't spent enough time reading the manual to find out what it *did* mean

Different x-over frequencies for different inputs. VERY interesting, this might help with the "music vs. HT" issue as well. Thanks !!

Exactly. I figure it doesn't hurt to run the sub+mains on music, especially if I set them to large. Sure, it's going through some sort of processing, but I can't hear the difference.

>>There was just more subtle detail I was hearing in peoples voices. It was as it all should be heard. I tested these sounds with four peoples voices in the movie just to be certain. Bilbo, Gandalf, Galadrial, and Frodo. All utilizing different spectrums of sound. Each one had just a little bit more clarity and soundscape when set to large. Untampered.

Just had a thought... did you still have the center crossover set to 60 hz when you did this ? If so, maybe the mains were just filling in the "60-80hz hole" -- I bet the VPxxx speakers roll off a bit below 80 so you would get a small "hole" in frequency response between 60 and 80.

Other question for everyone -- in a typical DVD (let's say LOTR) do the mains get DIFFERENT lf content from the LFE channel, or do they just get another copy of the same information. In other words, is the "reduced subwoofer output" from setting the mains to Large just the fact that one copy of the information is lost, ie dropping a few dB which could be negated by raising the sub output level the same amount ?

Or, in simpler words, when we switch from "small" to "large" on the mains should we turn the sub up a bit to compensate for the lost LFE or is it more complicated than that ?

Yup, you can lose info if the sub isn't set to above or equal the highest crossover on all the speakers.

LOTR is a prime example of what setting your speakers to small can do for your bass activity. Again, I spent a lot of time this past weekend just testing the center channel, though I did test all of them on and off. A scene where the hobbits first encounter the ringwraith, where he gets off his horse and crouches down on his hands...there's an incredible hit off bass when his hands hit the tree and leans over the hobbits. And it's only found in one place...the center channel signal. So if the speaker is set to large, you'll never hear it...the Hz signal is too low. But if you set the speaker to small and run it through the sub...whump! It's pretty powerful.

This is where the dilema comes in. Large is the full spectrum of quality sound, no compression (my thinking of what's happening) for the mains. Set to small...and you get more bass activity.

BTW, my crossover is disabled on my subwoofer. It's only taking in what the receiver gives it.

I would be interested if another H/K owner would run this test and see if they yield similar results. The test was mainly between (on the center channel) speakers set to 1) Small crossed over at 80 Hz, 2) Small crossed over at 60 Hz, and 3) Speaker to Large.

As I stated before...these test mostly were checking dialogue. Which, as far as I know, generally resides in the 1000-5000 Hz range...which should have nothing to do with 60 or 80 Hz cutoff.

Any thoughts...?

>>...there's an incredible hit off bass when his hands hit the tree and leans over the hobbits. And it's only found in one place...the center channel signal

Interesting. I didn't think the DVDs were supposed to be encoded that way. Question for you -- in the subwoofer "speaker" settings it looks as if only some of the options include the LFE channel in the text string that you pick. I assumed that was just to save space on the screen, ie "you always get the LFE channel but I don't have room to spell it out on every option" but now I'm starting to wonder if some of the crossover options do not LFE to the sub and only route LF content from the mains, center and surround. If that were the case then setting a speaker to "Large" would drastically affect what you get on the sub -- not a problem with the receiver, just "too many options".

I don't actually... um... HAVE a center channel speaker (although I'm gonna order one real soon, honest) so I might not be able to do this test. I will read up on the crossover settings some more, particularly this "does the LFE channel always go to the sub ?" issue. I suspect that the settings are the problem, not anything inherently wrong with the receiver (or so I hope).

JB

I like to run my M60s at large with the LFE sent to both the mains and the sub. Works for me. All "small" settings sounded pretty thin - and not at all acceptable for music. My $.02.

Well, you've got a newer generation of receivers, but the only place I see LFE+x is when the speakers are set to large, and you can change it to LFE. When they're small, I think it's assumed.

You're right. The 630 works the same way -- I was working from memory and mixed up the "Sub" and "LFE" settings. There does not seem to be any way to accidentally stop LFE content from going to the sub except by setting it to "None".

The interesting thing is that the 630 seems to let you send LF content from the mains to the sub even though the mains are set to "Large", but does not offer the same capability for the Center channel -- ie if you set Center to "large" then there is no center channel content going to the sub. Not sure why mains are treated differently (maybe for stereo ?)... but until reading posts in this thread I had always assumed that center speakers would always be "small" anyways.

The crossover treatment for the LFE channel is interesting. LFE can be low-pass filtered, but it shares a filter with one of the other speaker channels (ie you pick L+R or Center or Surround etc... and it uses the same crossover frequency as those speakers). This explains a lot, and tells me that I probably have some really stupid settings today and am losing some LFE content as a result.

None of this explains why running "Large" on the center channel gave Misfit Toy clearer dialog. I also don't understand why a deep bass slam would be encoded onto only the center channel and not onto LFE. I guess if either of those two changed then Misfit Toy would be happy again

If you run all speakers large, you truely are working in 5.1 (or 4.1 in your case)...the sub is ONLY getting the LFE channel signal that the designer designated for the subwoofer. In rare cases, it seems mostly with DTS movies, that low frequencies get sent to channels such as the surrounds and center channel. I assume this to be because movie theaters are equipped with speakers that can handle the full spectrum more efficiently. But home theater isn't designed that way, which is where the small speaker setting comes in. The subwoofers only job is to handle the low end. Basically the ideal setup is to cutoff your surrounding speakers for you subwoofer to take over the low end omnidirectional Hz range. Meaning you wouldn't know what direction the bass is coming from anyway, so why not send it to the speaker that can handle it.

What this means in an envirnment where all the speakers are set to small is...the subwoofer is getting it's LFE signal, or .1, from the DVD...PLUS all the low end frequencies that are channeled to it by the crossover in the receiver. Eqauting to a lot more low end activity than if all speakers were set to large BUT still getting all the sound we were intended to hear in the theater. So, speakers set to small is really the best way to get maximum impact out of your home theater.

Also, I sent and email and have called Harman Kardon seeking answers regarding what is/maybe really going on when the speakers are set to small on their receivers. They didn't have an answer for me when I called, so he told me to send an email and he'll pass it along to the technicians.

Hey, what's the email address on that? I'd like to ask about the delay settings...

I think it's one of the help desk reps, not a general email. But his address is graskin@harman.com.