Sub best at high crossover?


I am wondering, is my ears deceiving me, or is the Velodyne DD-18 actually sounding better, when I defeat the crossover (by setting it to max, 199hz), and turn the volume some steps down? This is in a fairly large room, with the sub well positioned, augmenting full range speakers. I hope others will share experience.
Ag insider logo xs@2xo_holter
Never trust YOUR ears or really, what is the point of this forum? Even if the suggestions here result in your hifi setup becoming an impractical pain in the ass and sounding like dog meat to you, you could be making some sort of aural mistake resulting in fun for you, but an utter lack of "geek credibility" among the Brain Trust...let this be a warning. Also, unless a "class field trip" to your house is organized, nobody around here will have a clue what your room sounds like. I'm sure this response was helpful. You're welcome.
The only real way to validate what your are hearing is to do a room response. there could be some suckout that the full range of the sub is complementing, or you might find that there is a huge hump in the upper mass response that you like, but you could refine the crossover and level once you know exactly what it is doing.
Hey, if it sounds good to you, then by all mean, continue on. The only problems I see are in two areas.

The first is that at some point (or frequency), bass becomes directional. In other words, you can hear the sub woofer, or that the bass is coming from a particular location in the room.

The second is that I believe that subs generally perform better when they don't have to cover a wide frequency range. I believe that the subs that I've used sounded better (faster and tighter) and were more accurate when they only had to cover up to around 50 or 60hz than they did when the had to cover up to 100hz or more.

Still, like I said, you're the only one that you have to satisfy, so more power to ya.
It could be the DD18 room compensation software, or maybe your power amp works happier with higher crossover point.
If you're asking what would explain your observation:

Your sub is providing smoother response up to 200hz than your mains are. IME, that will usually be the case for a well set-up subwoofer. No mystery there

Marty
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You're no longer using it as a, "SUB." 200Hz is close to a piano's Middle C(264Hz). BUT- As long as it makes you happy..... You may find this of interest: (http://greenboy.us/fEARful/frequencytables.htm)
What is your preamp source? If its a home theater processor then have you may have selected a crossover point in the setup menu in the processor. Taking the sub's crossover out makes sense because two crossovers in series can interact which causes problems in most cases. My Velodyne has a toggle switch which can completely remove it when fed via a HT preamp/processor.

If you are using a stereo preamp then taking the crossover out in the subwoofer would typically result in too much bass from my experience with my Velodyne 18" subwoofer. But if you like it that way enjoy.

I believe that you need to take measurements to setup a subwoofer correctly and then fine tune via listening. Just my two cents worth.
Thanks for response.
Wolf_garcia - I usually do trust my ears, thanks, but sometimes I am not quite sure, especially when the case is not so clear, plus it goes against the accepted rules...so thats why I am asking.
Tonyangel - agree, directionality and too wide range may be problems, but I don´t hear much of them at 199hz in my room. Instead the music has more dimensionality, depth especially, and sounds a bit more relaxed.
Emailists - yes there is a mid-room suckout, which is part of why I use the sub. I have measured, this is not a case of upper bass hump that I like. I run it at 199hz but turn it down, ok? The effect is mainly what it does to the rest of the spectrum.
Imhififan - yes, the sub´s equalizing is the suspect. A slight tension and flatness to the music. Subtle, though.
Martykl - I have the same result with different pairs of speakers. I had Dynaudio Consequence, some of the best there is regarding bass. So I don´t think it is because the sub does 200hz and below better than the main speakers (ok, from 30 or so, but this is not the main thing).
Bob_reynolds - yes, logically 35 or 45 or so would sound best with the speakers I´ve used. Only it doesn´t. At 199 the music feels "freer", more "here". Note, I never cut the low end from the main speakers, never liked that type of connection.
Rodman99999 - interesting link, but according to the table an 18 inch driver only becomes "undeniably directional" above 903hz. I am not quite there! It is perhaps slightly more directional, but that is less of a problem than the electronic glaze when I use the crossover.
Dms1 - too loud if taking out the crossover, yes, simple remedy, turn it down! I have it on 4 or 5 or so! (The preamp is the Aesthetix Io Eclipse).
So thanks all, although I remain a bit curious why other owners haven´t discovered this - if you have the chance, try it out!
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I never said anything about directionality. My reason for the post was the frequency ranges being overlapped. That site has chart, indicating ranges/octaves. Happy listening!
I never did trust speaker manufacturers' frequency response specs. They always embellish real world bottom end performance. Nothin like throwin a hammer in the mix to get some attention.
My post was supposed to be silly, and any other interpretation is strictly prohibited. I use test CD warble tones to see what my room is doing to the sound and then I mostly ignore that, but it is interesting to see where your main speakers actually stop producing useful bass, and where the sub goes. That IS useful information in setting the frequency point in the sub relative to the mains, but final tweeking is up to my wax filled and frequency challanged earballs.
I can see where having your balls in your ears, might present multiple problems.
The ideal situation has one setting the subwoofer to be coming in at the lowest possible frequency that works to provide the needed support. At higher frequencies, the subwoofer is working closer to the point where it is out of its element and your ear might be confused by the conflicting localization cues (the lower the frequency, the lesser your ability to localize the source of the sound). But, if, for example, you have a suck out at some frequency between say 150 and 200 hz because of floor-bounce cancellation of your woofers on the main speakers (a very common issue), the subwoofer might be filling in for that problem. To the extent the subwoofer can cure problems higher up in frequency than it is normally intended to help, I say stick with the higher crossover. It is MUCH more important to cure problems in the lower midrange than to have ideal subwoofer support at lower frequencies--the midrange takes priority.
I just encountered a similar experience. Crossing over my sub at 80Hz (used to be 35Hz) with sub built-in room correction. Very amazed it smoothly integrates with my floorstanders. Also in a relatively large room.
Here are my considerations so far.

First of all, it would be nice if more users of well-placed DD-18 subs (or similar) in fairly large rooms would chime in with their actual listening experiences in this debate.

What I hear in a situation with a good system and room, is a detrimental effect due to engaging the crossover in the sub. In many other situations, this may instead be a big plus, overcoming the minuses.

In my situation, I am not so much using the sub for what it does to the bass, since I have full-range speakers anyway, but more for what it does to the overall musical impression. The DD-18 helps my main speakers to "throw" the music at me and establish a depth perspective. It is the first of many subs I've used that I really liked. I had a Sunfire sub that was amazing although it danced along the floor and distorted a lot, and then, a Bowers and Wilkins that could never be woken from the big sleep. I next changed to a pair of REL Strata 3 that were quite good, but one DD-18 was even better.

This discussion concerns sub setup for augmenting speakers in fairly large rooms. My impression is, that if the positional and analog setup is good enough, it is best to "defeat" the crossover and the associated electronics. However, there is some give and take at this point, my best electronic presets with the DD18 sound very good also.
Since no-one has posted a DD-18 listening experience similar to mine, I wonder if it is partly caused by local circumstances, like the bass suckout in the middle of my room, and also because the effect is subtle, there is a give and take. I have my sub's presets set to 1 = crossover 199hz (defeat), 2 = 100hz, 3 = 80hz, 4 = 70 and so on down to 40 or so. These were set up through calibration. The flexibility of the sub is a big plus. The bass perhaps sounds more correct when I use lower crossovers. I've often felt that the standard 80hz sounds just fine, with most LPs. As I've said, this is much the rule through quite different pairs of speakers (they all run full-range, since this works best in my room - I learned that from my REL subs). So this idea of not using the crossover, and rather turn the volume 30 - 50 percent down compared to the presets, is something I've found out after some years of using the presets. Obviously this only works if the speakers are doing quite well in the bass. There is probably a price to pay in overlap speakers/bass but for me it is less than the problem of the equalizer in the sub, which somehow brings me closer to digital, and I am allergic to that.
O holter, this thread is getting silly. You've received rational advice and if it feels good do it advice. What is it you're looking for? I personally use a pair of Velodyne HGS-15s with an SMS-1 bass manager in a medium size room, so my experience is not the same as yours. I like to be unaware of the sub or any other speaker as the source of music. If it's an authoritative answer you seek, why not just go with the THX recommended 80 Hz; if it's an explanation for your perception, why not engage in magical thinking as so many other audiophiles do?

db
Impossible to question what your hearing or your taste in fidelity. I'm confused as to what your seeking here.

I owned a DD 18 and now two DD 12plus. I've never tried running them or any other subwoofer system full out. I mistakenly ran the DD 18 at 80Hz which bloated that region from the first moments. A touch of #1 preset put it right back in the groove.

Your speaker manufacture is rather vague regarding the frequency response of your speakers other than to say they have response down to 35Hz +/-? and that they are a ported bass reflex in design. Hardly what I would call full range, but thats me.

If your speakers are down -6dB or more at 35Hz and considering your rooms acoustical nature then supplementing that region would make sense.
Vicdamone, IIRC it used to be common practice to use the 3 dB down point when quoting frequency response limits. But that may no longer be the practice and it may never have been universal. Frequency response tends to drop like a rock below the 3 db down point.

db
Dbphd, that's my experience. Even if a speaker system actually measures reasonable output at 25Hz the room usually requires gain in that region.

I've gone round and round with some folks on Bass forums regarding their electric Bass cabinets which generally begin rolling off at 40-50Hz. While low E is about 41Hz there are fundamental overtones that reach well below and even further from a Double Bass.
Dbphd - I fail to see what is silly about asking about other users' experiences, or what this has to do with magical thinking. As others here have commented, there are often several ways to do it, much depends on the room, etc. And do you find it totally impossible that the equalizer has a negative effect?
OK folks, I am back in the fold. That is, I've changed speakers, I now have bipoles that go lower down in frequency, and have found that the sub now sounds best with the crossover at 40 hz or so. There is a plus and a minus, and what is most important varies with the situation.
Hello Holter.

I'm experimenting with sub placement and settings myself, coming from one REL Storm III and now running two very heavy DIY 12" Rythmik subs that sport many setup controls, and I also use a measurement mic, REW software and an external board.

Lately I'm experimenting with Dr Earl Geddes approach for setting up multiple subs (you can google it typing in that phrase), and I'm very happy with the results so far. This appproach calls for yhe use of at least two subs, one of which runs purposedly in overlap with the mains. I let mine go up to 110 Hz and limit the lower extension. The other sub takes care of the lowest frequencies. The final goal of Geddes approach is to achieve a smooth room frequency response, and while I'm far from done yet, I see it's working.

Worth reading, in my opinion. And the measuring equipment is sooo helpful to make decisions quickly, to later listen and decide with your ears.
Thanks for interesting info, Lewinskih01. I had two RELs once but never tried the setup you describe. Perhaps others here have experience?
An update from me.
I am back to a conventional setup, the sub closer to the wall, crossover at 50 or so, with my new full range Audiokinesis speakers. It sounds best at phase 90.
Although in some contexts the Velodyne DD18 sounds best on low volume with no crossover and no EQ, this seems to be quite special contexts. In my case, to get the timing and depth added value (more than the bass effect as such), it worked best with the sub front a foot or so in front of the speakers. This was not very practical in our combined living / listening room, however.
My purpose with this thread is only learning - all options should be considered. The DD18 is a good sub, able to contribute in different ways.