Axiom Home Page Forums General Discussion Home Theater M22ti and LARGE setting for DTS

Hi-

I have an HK AVR 520 with a pair of M22ti's for front
speakers and an EP175 subwoofer. When I play DTS encoded
DVD's, I have heard that the LFE channel is 10dB lower
than it should be and that the receiver needs to boost
it separately. However, my HK AVR 520 receiver is only
able to amplify the LFE when the front speakers are
set to LARGE. I typically set the front speakers to
SMALL and then direct the bass+LFE to the subwoofer.
This works fine but not for DTS movie DVD's.

Would setting my M22ti's to LARGE and directing the
bass to them and only the LFE to my EP175 damage my
front speakers at all?

Does anybody with similar equipment have any suggestions
for dealing with this?

In the long run when I am able to upgrade my front
speakers to something that is more obviously LARGE,
would the M60's be clearly considered to be LARGE?

Thanks!

Bruce

Bruce, what you report hearing about a 10db boost in the LFE channel(for certain technical reasons)when processed by the receiver is essentially correct. However, the 520 and all other HT receivers are designed to do this, whether in DD or DTS and whether speakers are set "large" or "small". Why do you say that your 520 "..is only able to amplify the LFE when the front speakers are set to LARGE"? Unless your 520 has a defect on DTS only which I've never heard of before I don't understand the problem.

You have a good sub and it's good procedure to set all speakers as "small"(regardless of how big they are)and the 520 crossover at probably 80hz. The crossover on the sub would then be turned up to the max to get it out of the way of the 520 crossover. This reduces the strain on both the main speakers and the amps in the receiver which drive them.

Hi JohnK-

Thanks for the response!

I had read about a problem with the H/K 520's ability to deal with a DTS LFE problem where the LFE track is 10dB too low on hometheaterforum:

(The thread is titled "DTS LFE problem and H/K 520")
http://www.hometheaterforum.com/htforum/showthread.php?s=ddd9053d100d4a74d76b44f029b27970&threadid=95640&highlight=DTS+AND+LFE+AND+520

In that thread, people speak of how only the LFE track requires a 10dB boost. Apparently the 520 has limited bass management capabilities and is only able to specifically boost the LFE track when the front speakers are set to LARGE. When set to SMALL, the 520 only allows the user to direct both the LFE and the bass to the sub. Boosting the bass (by boosting the sub output) would then end up increasing both the LFE and the bass (below the xover) when the speakers are set to SMALL.

This is all based on readings I've done. I have not been able to measure the system's LFE output on DTS DVD's to confirm that there is this problem. But, it's always fun to keep tweaking these things...

Thanks again!

Bruce

JohnK:
What is the reason to set your floorstanders to "small" and have the sub do the duty for LFE? Is it bad for the speakers to actually play the lower frequencies? If the speakers can play down to 35Hz why not let it play it? The reason for these questions are when I set my speakers to "small" it send all frequencies to what I set it to "60Hz" or lower to the sub. The speakers "seem" to sound better with the setting to "large". Thats why when I listen to music I set my speakers to "large" with the Sub off and no crossover. I like driving my speakers with full range in music mode. Is this bad? I just hate the fact that when I pop in a movie I enable the sub and re-setup the crossover to 60hz and then disable it when I play music.

In reply to:

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If the speakers can play down to 35Hz why not let it play it?

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First you have to realize not all the low bass is in the LFE channel, many times there will be low bass (as low as 20hz) mixed into the main channels too. So if your towers are set to large and they only go down to 35hz you're missing out on that bass. I just cringe when I hear people talking about setting their VP150's or bookshelves to large, because they're definitely missing out on bass that is there in those channels.

Second, you have to realize that the crossover is not a "brick wall", but actually a slope. In fact, the ideal recommendation is that your speakers should be able to play a full octave below the crossover point, since they will still be receiving a signal at those frequencies. That means that for a tower that can play down to 35hz the ideal crossover would be 70hz. Your speaker is still getting a signal well below 70hz, it's just rolled-off as you get lower. So it's not like you're wasting the capabilities of your speakers.

The reason a 80hz x-over is recommended is because even though 70 might be ideal for your towers, it's probably too low for the other speakers in your system. Since most receivers and pre/pros don't support multiple x-over frequencies, it's best to just cross everything over at 80hz. This probably means you're breaking the octave rule mentioned above for your center/surround speakers, but you really don't want to have your x-over any higher than 80hz because bass will start to become directional as you go higher.

Another thing to consider is that even though your speakers might be able to go down to 35hz, that doesn't necessarily mean they can play those frequencies as cleanly as a good subwoofer, especially at loud volumes. You would also be demanding more power from the receiver/amp for you mains, which may or may not be a problem. Factor this two things together and you can see that if you like to play at really loud levels (say, reference level DD/DTS or very loud music), you might be more likely to hit the limits of your system when your mains are set to large.

jKohn: Your explaination definitely make sense.
But this is what I noticed. Correct me at anytime if I'm wrong. I set my Rotel to Large. This gives the full range of sound to my speakers which can handle down to at least 35-38db. I do not get a "brick wall" when I set the crossover to none because what I read is that when I set the crossover to none in the Rotel it sends the full range of sound also to the sub. I then set my subs crossover to what I feel sounds the best which I think hovers in the 65hz and then raise the level of the sub to the same level as all the speakers with the sound meter. (A little overkill but it does level it off nice and cleanly). If I used the crossover built into the reciver and used the bypass on the sub and I forgot to turn on the sub then definitely my front speakers would have "hit that wall" to whatever I set it on the crossover if I set it to "small".

The other question I have is why your recommendation of having my receiver set crossover at 70Hz or 80Hz for speakers that go down to 35Hz which is like the Axiom M60. As I said above I noticed my crossover on the sub is around 65hz.
I can tell that going with DD/DTS the system is able to handle it but going from 2 stereo with no sub to all 5.1 channels running I noticed a drop of my volume running 53 to about 65 to get the same level with all speakers driven. Which leaves me to believe I might be purchasing an Anthem power amp to drive my 2 fronts by itself through pre-outs.

Rotel SX-1065 2 x 120w 8ohm / 5 x 100w 8ohm
Fronts: Monitor Audio Silver S6 6 ohm 35 - 30k handling 40 - 120W
Center: B&W CC6 8 ohm 78 - 20k handling 25W-120W
Surrounds: Axiom M22Ti 8 ohm 50 - 22k handling 10W - 200W
Sub: Mirage Bipolar BPS150 22 - 100 150W

In reply to:

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First you have to realize not all the low bass is in the LFE channel, many times there will be low bass (as low as 20hz) mixed into the main channels too. So if your towers are set to large and they only go down to 35hz you're missing out on that bass. I just cringe when I hear people talking about setting their VP150's or bookshelves to large, because they're definitely missing out on bass that is there in those channels.

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And what of receivers that can direct Bass to both the fronts and the sub?

Bruce, if I read your second message correctly, you haven't noticed any problem, just read about one that supposedly exists. I read the 42 posts on the other thread and thought that much of it was confused comment by those who didn't even recognize the difference between LFE and overall bass. Darryl and Lewis seemed more knowledgeable. I suspect that the reason you didn't notice this problem is that it doesn't exist. As I said, as far as I know all HT receivers, including the 520, have the required LFE boost. Some receivers have a LFE REDUCTION control, primarily to compensate for some early DTS productions which had the LFE too hot. Continue to set your speakers "small",get the sub cross out of the way, and don't worry about it.

Sat, I pretty much agree with Jeff's replies to you. If your Rotel allows you to bypass the receiver crossover(I'm not familiar with its bass management options)then yes, a full-range signal would be sent to both the sub and speakers and you'd have to use the sub cross to just reinforce the lowest octave or so. Again, both theory and personal experience tells me that if you have a good sub(and you do)let it have primary responsibility for what it does best(even when the mains have pretty good bass).Take part of the burden off of the speakers and the receiver amp sections driving them by setting everything "small".

I bow to wisdom of the veterans. All input is much appreciated.


Much thanks;
Saturn

In reply to:

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And what of receivers that can direct Bass to both the fronts and the sub?

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Well, the problem with that is that you're essentially doubling those bass frequencies by having both your sub and your mains. If you like the way that sounds, fine; but that's not how the source material was originally mixed to sound, you're basically adding extra bass to the overall mix.

Now some people would say "who cares, I like it that way." I say fine, more power to them; after all audio is supposed to be for enjoyment. But if your goal is to get the most accurate playback possible, I wouldn't recommend it.

Hi JohnK-

Thanks for your response and for reading through those posts...I'll set my speakers back to SMALL!

Bruce

Although many in these forums continue to only suggest one course of action for setting up a subwoofer (turning the mains to small and the sub cross all the way up allowing the receiver to handle the crossover typically around 80hz), i think home users should be given the other options and allow themselves to make the decision on what sounds best.
The "right" way of doing it is the way in which it sounds best to the individual user and no one should be told otherwise.

With that in mind, i do not prefer this 'standard' method for setting up a sub and i personally use my mains set to 'large' in the receiver with a reduced sub crossover.
The integration is smooth and the bass is taken up more by the main speakers and less by the subs. Only much lower sounds are enhanced by the sub in the range where the mains do begin to trail off. For me, this works well for both HT and music applications since i'm not big on having the huge sub sound play music but i like a good boom for explosions and thunder.
For an older post on sub crossovers chek out:
link to older post where sub crosses were also discussed

These are your equipment and you should set it up the way it suits your needs.

I followed the recommended setting (small with xover at 80 hz and 0 db on the receiver and 150 hz on the sub) because I did not want to strain my receiver and front speakers playing lower frequencies. I like the sound both in stereo mode and movies. In the evening if the sub tends to be too loud, I just reduce the volume. Although M80's can be set to large, the 12" sub is better equipt to handle this task than the 6.5" drivers of the M80's.

This way I also avoid the need to shift from large to small and vice versa when I play music or watch movies.

I compare it with hauling 200 lbs of bricks. I can use my car and it will definitely work but my pick up truck is better equipt to handle the task. Of course there could be other reasons why I might still want to use my car.

Hi Chesseroo-

Would setting my front speakers to LARGE (I have a pair of M22ti's) cause any damage to either my receiver or speakers? I've always been told to set them to SMALL and to let my subwoofer offload the receiver for driving the bass since it does a better job with the bass anyways.

Thanks!

Bruce

Subs, in answer to your question, setting your M22s to large will not damage them or your receiver. It simply allows the speakers to play their entire range of sound frequencies rather than starting to roll them off at the receivers crossover point (typically 80Hz).
The idea is to produce as wide a range of sound as smoothly as possible (e.g. no 'holes' in the sound frequencies from the absolute lowest to the absolute highest that your ear can hear).
However, given that you own M22s and a sub, i would recommend that you follow the advice to what JohnK and others had suggested (set M22s to small and use the subwoofer as you main speaker for bass).

For larger speakers, the towers, i have a different preference.
I've auditioned the M22s but i settled on buying the M60s instead. The full tower M60s (and of course the M80s and possibly some of the towers below the M60 as well), have a much greater bass extension than the M22s.
Hence, my M60s can play sound frequencies much lower than the M22s without such a large dropoff higher on the sound scale. Because the M60s have this capability, i've tested my preferences for bass by using the subwoofer for sound between 20Hz and 80Hz (approx.) and using the M60s for the sounds in this same range.
I did not like the sound of the subwoofer during music when it was allowed to play those frequencies right up to 80Hz. I preferred the tighter and less pronounced bass of the M60s as did my wife. But of course we still wanted to have some super rumbles during home theatre movie watching so the subwoofer still has its use.
If i have my M60s set to large, and they play sounds lower on the sound scale (e.g. lets say around 35 to 45Hz) before beginning to roll off (a function of their limitations), then THAT is where i would like to have the sub be used as a further extension of the M60s and to add some oomph in that extreme lower end.
So after some tweaking for sound in music primarily, i've now set my M60s to large and then used the crossover dial on the subwoofer to control how much or how little my M60s and subwoofer mix those low end sounds. At the present time my sub cross is set at about 50Hz with the gain (volume) at the 10 oclock mark and i find it integrates very nicely with the M60s.

Of course you can also try this with your M22s but when i played around with this configuration, i did not find that the M22s could produce sound frequencies quite low enough and well enough to make a difference whether i used the small or large settings but i did find their sound style to be very equivalent otherwise to the M60s.

With my M22 for music soundstage was not as good when crossover at 80 or even at 60. You loose the openness of the soundstage. So for music I switch the crossover off on reciever and set the speakers to large. And set my sub to 55Hz since the M22 goes only down to about 50 hz. For movies I switch my crossover of the receiver at 60 and set the speakers for small. A pain in the butt but it gives both modes the best sound quality. Whats 30 seconds to change settings.

I understand your thinking here Saturn in having the music sound a certain way that just doesn't cut it with the sub crossing at 80Hz.

Although my reasons were a bit different, it is easy to see why i've gone with the single setting route. I wanted to find a good crossover integration between my M60s and the EP350 for both applications. I did not want to have to make changes each time i played a dvd or a cd. I'm too impatient.

Have any of you tried using the high level inputs on your subs, then selecting "no subwoofer" on your reciever. This allows you the flexibility of setting the crossover exactly where you want it. You don't have to change anything when you go from movies to music.