# My graphs - advice appreciated



## Guest (Aug 28, 2008)

Any advice appreciated. If you think I should do something different and remeasure, I can do that. This is the best location for my sub based on experimentation (front corner for SVS and behind my seat for MBM).

Basically, I'm curious if I should equalize and/or get bass traps.

SVS PB10
HSU MBM 12
Treatments for reflection points (no bass traps)
I calibrated MBM and SVS using receiver test tone

Both subs (no mains), 80 receiver crossover; SVS crossed at 50hz










Both subs (no mains), 100 receiver crossover; SVS crossed at 50hz










Both subs (no mains), 150 receiver crossover; SVS crossed at 50hz


----------



## Guest (Aug 28, 2008)

Waterfalls (to see if you think i need treatments/eq)

Both subs (no mains), 150 hz crossover


----------



## Guest (Aug 28, 2008)

These two graphs are SVS only (no MBM or mains)

80 hz, no internal crossover










100hz, no internal crossover










sorry, didn't do a 150hz with svs only

waterfall of svs only crossed at 100 hz










vs. waterfall of both subs crossed at 100 hz


----------



## Guest (Aug 28, 2008)

my dedicated HT room  it's only 11 x9 feet. but it's my baby (ignore my DYI screen and speaker heights and black grill on my gray svs, still fiddling around/experimenting with stuff)


----------



## Guest (Aug 28, 2008)

graphs updated


----------



## Guest (Aug 28, 2008)

so, i'm wondering if i should keep the MBM-12 or if I should just go with a better sub (and get rid of the SVS) and return the MBM. 

I've heard an Epik sub and it sounded much better than my SVS (in a worse room too). So I'm looking at the Epik Castle and I'm interested in the MFW-15 as well. But not sure if one of those subs would be better than the SVS/MBM-12 combo I have. I do have a small room, so not sure how much the nearfield placement benefits of the MBM-12 come into play - I'm sitting only about 6 feet from the from the front of my SVS, so I think the tactile benefits (and the benefits of being close to midbass reproduction) might be there if I just go with one great sub instead of the combo. I don't know. It's time consuming and expensive to buy/return subs to test them out because of the shipping costs and lag between ordering and receiving (though HSU was superfast).

red: svs with mbm 80 hz xo on receiver, 50hz xo on SVS
blue: svs no internal crossover, 80 hz on receiver










red: svs with mbm 100 hz xo on receiver, 50hz xo on SVS
blue: svs no internal crossover, 100 hz on receiver










decisions, decisions


----------



## Guest (Aug 28, 2008)

anyone?

bueller?

am i a leper?


----------



## weverb (Aug 15, 2008)

union1411 said:


> anyone?
> 
> bueller?
> 
> am i a leper?


I know how you feel some times. It takes awhile for the experts to chime in. As for keeping the MBM. We can't answer that for you. Looking at your graph of just the SVS, you may not need one. Have you looked at applying Wayne's hard knee curve to your graph's? Do you have any type of BFD? There is a good chance you do not need the MBM. It will take some tweaking with a BFD to get there. If you are not interested in pursing/applying a BFD, then keep the MBM. It is obviously helping the range it was designed to.


----------



## HomeTRNut (May 30, 2008)

Well said, weverb...

union1411, I would think that your current set-up sounds amazing in your space....


----------



## brucek (Apr 11, 2006)

> anyone?


I don't personally buy into the mid bass module theory, so I'm a poor one to ask...... but I thought weverb said it best:

_As for keeping the MBM. We can't answer that for you. Looking at your graph of just the SVS, you may not need one._

brucek


----------



## Guest (Aug 28, 2008)

thanks for the responses. i'm gonna do some serious listening of the SVS alone compared to the combo (using blu rays that have great audio like Die Hard 4, Cloverfield, etc) and move the SVS around and see if the $500 for the MBM is worth it.

so, what about treatments or eq? so far does it look like i need them?


----------



## Wayne A. Pflughaupt (Apr 13, 2006)

union1411 said:


> Basically, I'm curious if I should equalize and/or get bass traps.


The answer is "yes." 

It looks like you have about a 5-6 dB drop between 20-40 Hz - an equalizer could help that. An EQ could also help craft a house curve.

As you probably know, what bass traps do is truncate low frequency decay times. Yours actually look pretty good for an "untrapped" room. That 60 Hz thing is nothing to worry about, probably noise from an electric mnotor of some kind - fridge, A/C, etc.

To get the most from waterfall readings, you might want to add the mains and extend the graph's upper limit out to 300 Hz or so, since bass traps (if you get them) can improve decay up that high. It's best to keep your output levels 40-50 dB above the noise floor, and the graph's floor should be a good reflection of the room's ambient noise floor. A 45 dB lower graph limit is fine for frequency response readings, but kind of high for a waterfall, since most domestic rooms have ambient levels at least 10-15sd dB lower.

As far as subs go, you might want to add the SVS model that Sonnie had to your short list. Forget the model, but it had two 12" drivers; I'm sure he could tell you what it was.

Regards,
Wayne


----------



## Guest (Aug 29, 2008)

thanks for responses again. i will fiddle with the waterfalls again with new settings.

i made more measurements tonight with SVS only (no MBM). 

80db sweep; 80 xo; and this time the mic was placed much closer to where the person's head would be, using tripod. and no audyssey whatsoever (left Multi-EQ on last night by accident).

left seat and right seat. pretty amazing what this little sub can do. now i just need to sit down and A/B the combo and svs only. my impression the past using the combo with the MBM is that the midbass is more textured, so the sound quality is richer than with SVS only, of course that could be placebo.


----------



## Guest (Aug 29, 2008)

SVS-only and placed in right corner. same receiver settings as above. me likey.


----------



## weverb (Aug 15, 2008)

What are your plans now for the MBM?


----------



## Guest (Aug 29, 2008)

weverb said:


> What are your plans now for the MBM?


Returning it. 

I did some listening of SVS alone last night on Die Hard 4 lossless (I've memorized it by now) and compared to the combo with MBM. I get the same tactile response with just the SVS and the midbass sounds pretty much identical - at one point I actually thought the SVS alone sounded better during a certain scene with gunshots, but that could be explained by the fact that it's a little harder to calibrate two subs than one. Either way, for my room, because it's so small perhaps, the MBM just doesn't offer $500 of value for me. 

Now I'm looking at possibly replacing the SVS with the Epik Castle or MFW-15. 

I love the sound of the Epik sub I heard before and that was just the Caliber. And Castle goes significantly lwoer than my SVS, which is nice because with my leather seats and small room I get alot of tactile response in my booty  I'd be the first to buy buttkickers but I simply do not need them in my setup. 

As for the MFW-15, according to craigsub on avs in that huge thread, he said he loves its midbass slam but i believe he implied that the castle is better for going lower - don't quote me on that though; i have to reread the thread.

Kinda silly that i'm considering upgrading my sub for that small of a room, but it's my mancave and i appreciate good subs when done right.


----------



## weverb (Aug 15, 2008)

union1411 said:


> Kinda silly that i'm considering upgrading my sub for that small of a room, but it's my mancave and i appreciate good subs when done right.


It's never silly. :bigsmile:


----------



## etcarroll (Mar 17, 2008)

Perfectly understandable.

I was at a GTG and watched the shootout in Open Range on a system with a pair of MWF-15s that Mark Seaton had calibrated. The individual shots could be felt in the chest. It's the experience that made me dload REW and finally begin tweaking my SVS PB12+2 once and for all.

But I'm thinking it may be time for something newer.



union1411 said:


> Returning it.
> 
> I did some listening of SVS alone last night on Die Hard 4 lossless (I've memorized it by now) and compared to the combo with MBM. I get the same tactile response with just the SVS and the midbass sounds pretty much identical - at one point I actually thought the SVS alone sounded better during a certain scene with gunshots, but that could be explained by the fact that it's a little harder to calibrate two subs than one. Either way, for my room, because it's so small perhaps, the MBM just doesn't offer $500 of value for me.
> 
> ...


----------



## Guest (Aug 30, 2008)

Ok I might have spoken too soon about the MBM. I realized I had not calibrated it correctly. So tonight I did (like this: MBM to speakers, then SVS with internal x/o to MBM, then the combo with internal xo to speakers).

Result (hearing-wise, not REW): wow. Much better than the SVS alone, especially with gunshots, etc. A lot more tactile. SVS is tactile in my room, but this is another level of tactile. Will try more movies and run REW again - bye bye weekend  

Even though MBM combo now sounds a lot better, still not sure if I'm better off getting one very good sub and dismissing these two. No way to know unless I buy a new sub and compare  I love being single. Or maybe this is why I'm single. hmmmmmm


----------



## Guest (Aug 31, 2008)

did some more measurements

as i suspected from watching movies, Dynamic Eq (not to be confused with Dynamic Volume) via Audssey is boosting the bass. and i was careful to check the SPL level when switching back forth from dynamic so the sweep would still be at 80db. left the mains on



No Dynamic Eq












With Dynamic EQ


----------



## Guest (Aug 31, 2008)

graph looks prettier when i cross to 120 hz. less sharp dips in the 60-90hz range. i wonder if that's because i'm using the mbm-12. Dynamic EQ is on in this graph.


----------



## Guest (Aug 31, 2008)

should I turn off Audyssey entirely when measuring? is that the best way to reveal what my room's problems are? well, since i have Audyssey in my receiver, then i would think i should turn it on because i'm using these graphs to see if i need extra EQ (like BFD or 8033 or whatever) and/or treatments. correct?


this is my graph with Audyssey on (120 hz xo; using mains and MBM-12; no Dynamic EQ)











and this is with all Audyssey off


----------



## Guest (Aug 31, 2008)

Wayne A. Pflughaupt said:


> It's best to keep your output levels 40-50 dB above the noise floor, and the graph's floor should be a good reflection of the room's ambient noise floor. A 45 dB lower graph limit is fine for frequency response readings, but kind of high for a waterfall, since most domestic rooms have ambient levels at least 10-15sd dB lower.



Thanks but I'm curious about the fact that my SPL reading on REW is around 57 db when there is no signal through my receiver - like right now while everything is idle. So, isn't 57db my noise floor? I live in NYC 


this is my waterfall with no Audyssey on. Mains and MBM-12 are on. apologies if graph isn't set correctly. these waterfalls are finicky. 

35db floor you recommended











i have no idea if this means traps will make a significant difference or not.


this is the 45db floor


----------



## Wayne A. Pflughaupt (Apr 13, 2006)

> Thanks but I'm curious about the fact that my SPL reading on REW is around 57 db when there is no signal through my receiver - like right now while everything is idle. So, isn't 57db my noise floor? I live in NYC


Keep in mind that the meter in C weighting has fairly flat response down to about 40 Hz. Also keep in mind that it can only register _one figure,_ and that will be the frequency that is the loudest.

Take a look at your graph, especially the highlighted 50+ Hz area:







​

Notice that the 50+ Hz signal is not decaying, like the rest of the signal is. I'll bet if you re-frame the waterfall with a 600 or 1000 ms window, you'll see that it doesn't decay there, either. In other words, its a steady-state signal that's not coming from your HT system (notice the way it "emerges" from between two peaks). 

What it is is background noise from some other source - which in NYC could be just about anything.  _That's_ what your SPL meter is registering - notice it's at or above the 57 dB figure you registered...



> i have no idea if this means traps will make a significant difference or not.


If you use enough of them, bass traps will deliver a faster rate of decay, as these graphs show:



















That said, your waterfall doesn't look bad, with everything above 50 Hz pretty much fully decay'd by 300 ms. That's nearly twice as fast as the top (no bass traps) picture above.

Regards,
Wayne


----------



## Guest (Aug 31, 2008)

thanks for the reply

also, by staring at the graph for a while, i think i understand it more now. in my first graph at 300ms, above 100 hz, basically nothing is above 50 decibels. so that seems pretty good to me. bass traps are pricey - and i don't want to ever do DIY again after i buily my screen - so i think i'll hold off on them for a little while. i'm probably better off spending the $$ upgrading my svs than buying bass traps at the moment.


----------



## JohnM (Apr 11, 2006)

union1411 said:


> did some more measurements
> 
> as i suspected from watching movies, Dynamic Eq (not to be confused with Dynamic Volume) via Audssey is boosting the bass. and i was careful to check the SPL level when switching back forth from dynamic so the sweep would still be at 80db. left the mains on


You will not be able to get a representative measurement from any "dynamic" features using a swept sine, the nature of the signal is very different from anything a dynamic feature might be configured to process, different sweep lengths and end frequencies (and hence different rates of frequency change during the sweep) could give very different results. A better idea might be to use the RTA graph with the Periodic Pink Noise test signal, that would give you a view of the dynamic response with a signal that has content across the band.


----------



## Guest (Sep 2, 2008)

Thanks. Does your post apply to regular Audyssey settings as well? In other words, running REW and leaving Audyssey on but turning Dynamic EQ off.


----------



## brucek (Apr 11, 2006)

> Does your post apply to regular Audyssey settings as well?


No, the Audyssey filters will be similar to a BFD EQ filter. It isn't dependant on the sweep.

brucek


----------

