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Warpdrv's Dual Opposed 18" LMS's..... "The XLerators" - Page 11

post #301 of 507
9/2/10 at 7:42am
Quote:
Originally Posted by LTD02 View Post

something got botched with the final response line. it should go from 15hz to 200hz, not from 10hz to about 125hz. the scaling seems right; it just needs to be shifted to the right.

Here ya go:






Bosso
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post #302 of 507
9/2/10 at 8:38am
My heads hurtin' with all this....

Proper gain structure dictates getting the signal up out of the noise, asap, and leave it there (not cutting and subsequent boosting).

After placement decisions have been made (considering response smoothing and elimination of deep nulls), and multiple arrival time or phase issues have been addressed ,........apply the boost needed for a small sealed box. Lop off what ever peaks one encounters w/ the speaker room interface. Done

Slowly increase volume with proper attention to amp clipping and driver bottoming. Have fun
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post #303 of 507
9/2/10 at 8:50am
Thread Starter 
Quote:
Originally Posted by FOH View Post

My heads hurtin' with all this....

Right......
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post #304 of 507
9/2/10 at 8:59am
Penn, please read through my very simplified post again. Your post only holds true if you never re-adjust your levels on the sub after/while adding EQ. When adjusted to the same levels to work with the mains there is no difference.
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post #305 of 507
9/2/10 at 9:14am
FOH, don't forget about input/output ceilings, both digital and analogue at every point. If it was all pro gear you could gloss over them, but in the prosumer world of mixed/non-standard levels the DNR and SNR concerns are a big problem.
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post #306 of 507
9/2/10 at 9:22am
Quote:
Originally Posted by Warpdrv View Post

Maybe I should Add and IB ? Just to make things interesting..... ?

Just above the upper acoustic panels there is attic space.......


Now we are cooking. You know xxx 18's make great IB drivers.

On a serious note though. Looking at the amount of boost that you'd need, you should probably go for a shelving boost with the DCX starting near 25hz or so (you'll have to experiment) and roll in around 6db of boost. Maybe 8 or 9db if 6 isn't quite enough and you are brave. That should get the 15-25hz area more in line with 30-100hz. Below 15hz will still be well down in level but it'll be brought up the same amount. I wouldn't try boosting that stuff enough to get it back in line with the upper bass. After that try to figure out and set-up the limiter in the DCX like I suggested before. Do some reading up. That might be a PITA but I think it would be worth it to keep your drivers and amps out of overload on peaks when using a large amount of low end boost.


What internal volume are your subs anyway?
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post #307 of 507
9/2/10 at 9:33am
Quote:
Originally Posted by FOH View Post

My heads hurtin' with all this....

Quote:
Originally Posted by Warpdrv View Post

Right......


Heheheh. I don't blame you. Some are making this seem tougher than it really is. Bosso summed it up real nice. Thanks, Bosso!

I think one of the best things going for the Bassis, besides what Bosso listed, is that it is an analog component. There is no extra D>A>D process so as mentioned the S/N ratio is very high and response is very extended. Not only this but it is very flexible and super easy to use. Imho, it is more powerful than a DCX for L/T use. I can't wait to get my own.

Quote:
Originally Posted by bossobass View Post

being told why I do things or being incorrectly corrected has just become not something I prefer to do with spare time.

That's a sig worthy quote if I've ever seen one.
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post #308 of 507
9/2/10 at 9:52am
Exactly Scott,

I just Swaped out my DCX for A First of its type According to Phil, Marchand Bassis (Balanced/ 46db)high end Attenuators 9Hz Filter Ecc that I finnished building from scratch and all I can say is that it absolutely blows the DCX out of the water, & that is only Setting up the LT by going off my WinISD/LT model thus far...

I say Go with A Bassis, I am so glad I listned to BOSSO ...
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post #309 of 507
9/2/10 at 10:20am
Thread Starter 
Quote:
Originally Posted by Ricci View Post

Now we are cooking. You know xxx 18's make great IB drivers.


What internal volume are your subs anyway?


Should be roughly about 8.5 cuft all in....
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post #310 of 507
9/2/10 at 10:48am
Quote:
Originally Posted by penngray View Post

Im my simplistic view....

If you cut -12dB at say 50Hz you need 4 times the power to get back to the original unEQed output. Meaning 4000Watts will get you what 500Watts would have given you without the -12dB cut to flatten the curve. This method gives a nice controlled response during high SPL and low SPL moments.

If you boost 12dB @ 20Hz, you need 4 times the power at that level. Meaning if you are playing SPL levels taht require 500Watts @ 50Hz then you require 4000Watts @ 20Hz to keep the response flat. With boosting you can go to 4000Watts on the higher frequencies getting more output while you will just clip the lower content.

Boosting gives you more headroom but pushes the amp into clipping much, much faster when there is content down low. The great thing though is that most content is above 20Hz so you are giving the subs that full 4000Watts of power to enjoy max SPL.


conclusions for me. Cutting allows for the best overall response curve no matter what the SPL level is along with less amp clipping. Boosting allows for the most SPL sacrificing response curve and amp clipping/distortion/levels.


Its easy to see why Bosso wants 10,000Watt amps. Boosting 20dB needs a CRAP load of power!!!

That's how I understood it. For what its worth, when I said headroom I was referring to wiggle room before clipping occurred. Sorry about the confusion there.
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post #311 of 507
9/2/10 at 10:55am
Quote:
Originally Posted by Ricci View Post

Maybe 8 or 9db if 6 isn't quite enough and you are brave. That should get the 15-25hz area more in line with 30-100hz. Below 15hz will still be well down in level but it'll be brought up the same amount. I wouldn't try boosting that stuff enough to get it back in line with the upper bass.

I agree

Bosso
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post #312 of 507
9/2/10 at 10:58am
Quote:
Originally Posted by bossobass View Post


The main point here that I agree with is that, contrary to popular belief, based on erroneous posts in the past that bring up auditory masking, equal loudness contours, house curves and the like, below 20Hz does NOT have to be EQ'd to a flat or rising response in room to be appreciated.

Yup. Everyone seems to forget you are not supposed to HEAR the <20hz tone but feel it. In which case the human body does a much better job than our ears do.
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post #313 of 507
9/2/10 at 10:58am
I must say, I'm learning a lot from you guys. Thanks for all the contributions you make.
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post #314 of 507
9/2/10 at 11:05am
Quote:
Originally Posted by bossobass View Post

The main point here that I agree with is that, contrary to popular belief, based on erroneous posts in the past that bring up auditory masking, equal loudness contours, house curves and the like, below 20Hz does NOT have to be EQ'd to a flat or rising response in room to be appreciated.

Where is that a popular belief?
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post #315 of 507
9/2/10 at 11:09am
Quote:
Originally Posted by soho54 View Post

Where is that a popular belief?

I have seen it everywhere in the time that I have been doing the online audio forum thing.

Here is the latest but these threads are a dime a dozen...

http://www.avsforum.com/avs-vb/showthread.php?t=1271826


The ELC in not directly mentioned but in the OP's first post it is worded as "useful" output. Remember, for these people, it's impossible. You need, like, billions of watts ... man. These guys seem to have a selective memory when it comes to sealed subs and that cute little thing call PVG or room gain.
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post #316 of 507
9/2/10 at 11:18am
I don't venture deeply into the other audio forum sections here very often, unless nothing else is going on around here. Those guys can be odd.

I thought it might have been HTS again, or something.
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post #317 of 507
9/2/10 at 1:45pm
Everytime I hear about the Bassis I go back and am tempted to buy it. But looking at this pic ... it just looks imposing as I have no clue what "Qs" vs "Qb" do, and didn't originally as I wanted a device with a Phase control on it.

Curious, I'm currently using 3 PEQ Filters on the DCX and a low shelf boost of 6db at around 25hz IIRC to mimic an L/T and get me pretty flat from 15hz up.

How would one do that with the Bassis?

Sorry to hijack the thread Warp!

Excuse me if that is a dumb Q!
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post #318 of 507
9/2/10 at 2:10pm
Quote:
Originally Posted by pbc View Post

Everytime I hear about the Bassis I go back and am tempted to buy it. But looking at this pic ... it just looks imposing as I have no clue what "Qs" vs "Qb" do, and didn't originally as I wanted a device with a Phase control on it.

One is the system 'Q'. Ie: the final 'Q' of the subwoofer driver + enclosure together. The other is for the net 'Q' of the whole sub system and Bassis device together.

For example: I will build a sealed subwoofer with my RLp18d4 that is a 24" cube or about 170 liters. I get a 'Q' of about .753 with some stuffing. If I wanted I could change that to .5 or 1.2 or anywhere between, all on-the-fly, using the Bassis.
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post #319 of 507
9/2/10 at 2:23pm
So IIRC, in my case my system "Q" was 0.644 before about 3lbs of stuffing (sounds like a turkey).

So I'd set the Qs to 0.6 let's say, and then the Qb to the desired Q? Then adjust the Fs to (in my case) 25hz and apply a 6db boost for the L/T?

Wouldn't one still need a P-EQ though to tame any remaining peaks/dips in the response?

I need an "idiots guide" to the BASSIS!!
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post #320 of 507
9/2/10 at 2:35pm
Thread Starter 
Quote:
Originally Posted by pbc View Post


How would one do that with the Bassis?

Sorry to hijack the thread Warp!

Excuse me if that is a dumb Q!


No worries - I as well am wondering what all the big deal is about with the Bassis as I don't truly understand it either...
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post #321 of 507
9/2/10 at 2:39pm
Quote:
Originally Posted by pbc View Post

So IIRC, in my case my system "Q" was 0.644 before about 3lbs of stuffing (sounds like a turkey).

So I'd set the Qs to 0.6 let's say, and then the Qb to the desired Q? Then adjust the Fs to (in my case) 25hz and apply a 6db boost for the L/T?

Wouldn't one still need a P-EQ though to tame any remaining peaks/dips in the response?

I need an "idiots guide" to the BASSIS!!

Absolutely. Yes, you will still need a PEQ if you want to do anything to peaks or dips. That is not what the Bassis is for. It is pretty much best used for L/T duty but it is great for transforming not so well designed speakers too but I think this audience would not go to the lengths of using a bassis to correct an improperly designed speaker. Heheh.

I don't know a ton about the adjustment of the Fs as that is all user dependent. Bosso might be able to help out on that one. KGveteran has had one in his system for a long time too. I've known of it for some time but I am just now making the transition to sealed.

Could have sworn that there was a guide on using the Bassis somewhere on the net. Did a search just now and couldn't find one. Hmmm.
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post #322 of 507
9/2/10 at 3:59pm




Bosso
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post #323 of 507
9/2/10 at 4:19pm
A Bossobassis manual would be great even though I only have the normal stereo bassis which I don't currently have hooked up.

I get the basics of how to use it but I know I am not using it close to it's full potential, at least I don't think. Right now there are too many other things going on to mess with the system but soon I will get the bassis back in the mix when I build my LMS-U pair.

I think the Bassis would sell much better if it weren't such a head scratcher, maybe the Bossobassis is just what's needed to make it a best seller.
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post #324 of 507
9/2/10 at 7:42pm
i'm not following. a dcx can do all this. are folks confused?

an LT can be applied with three filters.
1. eq the system to a 0.707 (by either lowering or raising spl at the corner)
2. apply a 12db per octave shelf
3. eq the system to whatever final q you want (by either lowering or raising spl at the corner)

in practice, all that is typically required is the shelf filter. it preserves the q of the sub (more or less), but moves the corner much lower in frequency.

maybe this marchand box works some sort of magic, but i'm not seeing how it can possibly compete with a dcx that would seem to be able to provide similar functionality, plus a whole lot more, at a lower pricepoint. i don't have any horses in this race. if the marchand bassis kills the dcx, i'm with phil.
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post #325 of 507
9/2/10 at 7:58pm
Okay - we are getting waaaaay off topic here, even though it is useful info. So, from the top:

If we had to start over, what should be done differently? This is obviously a very large room we're working with, and it's not easy to "get it right," so we're going to need the help of the entire collective here. I realize we all do things a little differently, but a unanimous "Hey, do this" would be very helpful. Also, keep in mind that warp isn't willing to experiment with subwoofer placement, unless something has changed in the last two days. The goal is a relatively flat response with enough ULF content to make us all grin from ear to ear. And obviously, output headroom (no clipping) needs to be a priority, and this man likes to listen LOUD! We already bottomed out a driver during WOTW last week, so that needs to be prevented.

Based on what I've read from you fine folks, I'm certainly in agreement that in this situation independent EQ might not be the best approach; I don't mind EQing all the subs as one. So that's the number one thing I've taken from your comments. Now, what else should be done? And please, dumb it down for us regular folk
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post #326 of 507
9/2/10 at 8:03pm
Quote:
Originally Posted by bossobass View Post

I agree with this, except for the amount of boost applied. I stand by my recommendation of starting with a +12dB L/T boost.

Bosso

Last night after installing my new Bassis, playing Infected Mushroom CD I started with +8db boost but ended up bumping it up to +14db thus far , as Bosso so rightly points out this is where Big power amps are A must...

The Bassis uses only High quality Components also has the ability to be customised to your requirements such AS 7Hz cut or whatever instead of the stock 20Hz by simply swapping out 3 Polypropylene Film Capasitors,
per WM-8 board (For 7.4Hz cut - 0.27uf caps 50V)

Cheers...
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post #327 of 507
9/2/10 at 8:05pm
Thread Starter 
Quote:
Originally Posted by Nuance View Post

Okay - we are getting waaaaay off topic here, even though it is useful info. So, from the top:

If we had to start over, what should be done differently? This is obviously a very large room we're working with, and it's not easy to "get it right," so we're going to need the help of the entire collective here. I realize we all do things a little differently, but a unanimous "Hey, do this" would be very helpful. Also, keep in mind that warp isn't willing to experiment with subwoofer placement, unless something has changed in the last two days. The goal is a relatively flat response with enough ULF content to make us all grin from ear to ear. And obviously, output headroom (no clipping) needs to be a priority, and this man likes to listen LOUD! We already bottomed out a driver during WOTW last week, so that needs to be prevented.


Lets just hold the phone until we do some measuring again....

I don't need to continue down all these roads about this or that....
Please feel free to start another thread about the Bassis vs the DCX - for right now, I'm listening and I'm happy with what I have, and I'm not pushing the limits until I get some more definite measurements. But I will say right now - its loud, shakes the hell out of this place and it sounds awesome and I got plenty of low bass with the low end boost I applied. And until I see different with measurements I'm going to sit here with a huge freakin grin on my face

I really appreciate all your help thus far, it has been priceless in direction.

Warp
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post #328 of 507
9/2/10 at 8:13pm
Quote:
Originally Posted by Scott Simonian View Post



The ELC in not directly mentioned but in the OP's first post it is worded as "useful" output. Remember, for these people, it's impossible. You need, like, billions of watts ... man. These guys seem to have a selective memory when it comes to sealed subs and that cute little thing call PVG or room gain.

Have you seen how much 'pressure' an open cylinder holds? Do you guys see that thing called a fireplace, connected to a chimney to like.... the outdoors?

What about that huge bay window, as well as the two other windows on that wall.... the O/P's room is a resonant floor over a basement, and the one wall that seperates the main room with the subs and the kitchen / dining area has huge openings, plus it's like 20 feet to the top of the stairs.

There is no 'sealing' that area at all. The house is pretty open with hallways to the garage area, upstairs and the basement.

What you have is a huge box with openings and chambers that act as hemholtz resonators.

I think that Warp has an awesome room, he's done damn near everything he can to get great response over a few seats. ( without resorting to moving the subs to different locations )
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post #329 of 507
9/2/10 at 8:39pm
Quote:
Originally Posted by michael hurd View Post

Have you seen how much 'pressure' an open cylinder holds? Do you guys see that thing called a fireplace, connected to a chimney to like.... the outdoors?

What about that huge bay window, as well as the two other windows on that wall.... the O/P's room is a resonant floor over a basement, and the one wall that seperates the main room with the subs and the kitchen / dining area has huge openings, plus it's like 20 feet to the top of the stairs.

There is no 'sealing' that area at all. The house is pretty open with hallways to the garage area, upstairs and the basement.

What you have is a huge box with openings and chambers that act as hemholtz resonators.

I think that Warp has an awesome room, he's done damn near everything he can to get great response over a few seats. ( without resorting to moving the subs to different locations )

My comment regarding ELC was in no way directed towards Warp and his room. It was a reply to Soho54's comment. Obviously, Warp does not benefit from any free gain.
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post #330 of 507
9/2/10 at 8:55pm
"Okay - we are getting waaaaay off topic here, even though it is useful info."

"I don't need to continue down all these roads about this or that...."

sorry guys, your work just inspired a sidebar conversation about different methods for optimizing the bass (eq and LT). at least two options that were presented were the marchand and the dcx. we are all on the same page, whatever works, works.
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