Seaton Sound SubMersive1 - Page 173

Thanks. It's good to see what people come from. Looking forward to some more thoughts and measurements.

Hi Geordon,

Good to hear the upgrade was noticeable, even with PGM 1(IN). The difference between the two curves is specific response EQ. The only case I could see an argument for the different response programs would be if you measured the frequency response of the subs and found that one of the locations contributed minimally down low, but plenty up high. In the vast majority of cases you would want both subs sharing the workload to offer greater headroom.

The difference in maximum playback levels can be no more than 4dB on the dial. Both programs hit max output at the same level at each frequency, they just start with different response curves. You will only see a 3-4dB difference in max playback levels when the content is dominated by energy below ~30Hz.

I look forward to seeing your measurements. Be sure to measure each sub individually and then combined without changing the levels. This is the most telling measurement. The subjective improvement of more than double is very possible with workable locations and not surprising at all. Doubling the power is ideally 6dB, but different locations in the room can easily be 2x more efficient (12dB difference) over certain ranges. If material you are listening to has plenty of energy in a valley in the response of your original subwoofer, it can easily sound 2-6x more powerful.

One hard to communicate concept is that delivering all of the subwoofer range more efficiently and evenly subjectively adds a lot of content and power, as notes and details aren't missed or way too low in level. You might kill some rumbling peak in the room that pegged the SPL meter as you smooth the response, but there is much more info to be heard and overall it is more exciting to listen to.

Even though I've had my SubMersives for over a year, I have done very little music listening due to some nasty room problems (that had nothing to do with bass frequencies). Much of that problem (unfortunately not all) has been dealt with so for the last 3 weeks or so I have listened to more music than in the previous 3 years. I have been using the subs for movies during that time and have been incredibly impressed, particularly since I have owned at least 10 different kinds of subs prior to purchasing the SubMersives.

What I have discovered (that I did not notice on movies) was the ability for the SubMersive(s) to very clearly articulate the various kinds and textures of musical bass notes which really helps to add to real music enjoyment. (I guess an explosion/gunshot/etc doesn't demonstrate that attribute very well!!). The more I listen, the more impressed I am with these subs.

While $2000 is not chump change, in this case, it provides incredibly high value. Certainly one of the top two or three audio purchases I have made in the last 40 years!!!

If anyone out there is considering this sub versus virtually any other sub on the market, run (don't walk) to your telephone and call Mark and buy one (or 4)!!

I have to agree with the music aspect. Since Craig did such a great job of blending my JM Labs and the sub together, music just sounds fantastic. I can't tell where my speakers stop and the sub starts. Although, I must confess, I am an explosion guy as well .

Here are my results with dual Submersive HP's:

(note: all measurements were with the DSP button in the out position and there is no LP filter on the sub)

This first graph is of the subs comparing each sub individually and together:
(BLUE=LEFT SUB, RED=RIGHT SUB, and BLACK=BOTH - NO SMOOTHING)



This graph is of the dual subs together and EQ'd with my SMS-1:
(NO SMOOTHING)



This graph is with my mains mixed in:
(NO SMOOTHING)



This final graph is the same as above but with 1/3 octave smoothing:



Listening impressions:

While the measurement I took to start was pretty good, the frequency response was not as flat as you see with both subs EQ'd together. For music, I notice a heavier bass sound, but it's not a big difference from running just 1 sub. I don't think I've gained much of anything frequency response wise. The subs are still heavily EQ'd, but it is different.

For HT, the story is still different. For HT, I run the subs about 2-3db's hot. There is still a great deal more presence and impact from running dual subs vs. 1. I'm not exactly sure I understand why as the subs are measuring very similarly and the level is set the same. Any deep bass notes seem really shake the floor now. There is a lot more visceral impact than with just 1.

One thing I do notice after being at a friend's house listening to his subs. I do not have very good upper bass. I suppose it's caused by that 65-100Hz dip I have. I need to get that figured out. Anyone have any ideas?

Looks like a combination of a subwoofer location resulting in the 65-100Hz valley. Where are the two locations now? Looking at the measurements and description, it looks as though they are both at the front left & right? I suspect getting one at a different front - back location (ie toward the rear) would help in this regard. I also suspect some tinkering with the distance setting of the subwoofer to play with the sub-speaker integration could help, especially if you can get a location that fills in the upper range.

Finally, I would also experiment with generally raising the level of the subwoofers. Don't be afraid to raise them up a good deal, as the SPL meter readings for the main channels do not account much for level below 500Hz. Depending on the relative balance of the speakers, you could easily justify a good deal higher level, and the graphs suggest that wouldn't be out of line.

Mark,

I want to first thank you for all of the support you give on these forums. It makes me even happier to own your products.

You are correct, the subs are on the left and right sides of my entertainment center and on the inside of the main speakers:



The submersive in the picture is mine. The borrowed one is located on the right side where the vase is in the pic.

When I had my PB13-Ultra, I tried many locations and orientations. The location where the submersive is, is by far the best measuring and sounding location. As a matter of fact, I sold my BFD I used to use for EQ'ing my PB13-Ultra because I ended up not needing it. I used its on-board single band parametric EQ to get this:



I'm not following you on the location change for the subs. This is a rare opportunity I have, and I want to make the most out of having 2 subs in my room. Where is "toward the rear" mean exactly?

You may not remember this Mark, but I have a more complicated setup than most. I basically have a 2-channel setup that is HT capable. My tube preamp has HT-bypass and I only use the SMS-1 in the music chain. I'm currently using Audyssey room correction in my Onkyo 876 receiver for HT purposes. I don't expect perfection on the HT side, just the music side. The graphs are all based on the music side of things. This means that I have no distance correction available to me.

Am I a lost cause or what?

The SMS-1 has a Phase control on Page 2. It's not exactly the same as a Distance control, but it might very well help with that big dip at 80 Hz, (assuming you're using an 80 Hz crossover.)

Craig

Is there anyone in the St. Louis, MO area that has a submersive and competent to help this novice ensure I have a sound setup of my system?

Thanks Craig. I can't say I'm any sort of professional sub tuner, but I'm not a complete novice (although I feel like one a lot). I did adjust the phase to 90 to get a better looking graph. It worked.

I'm currently using those RCA type high-pass filters. The HPF of the SMS-1 seems to affect the sound a lot more than using my RCA filters. I've tried it several times and I come to the same conclusion each time.

But you can't adjust phase or distance with the SMS on two separately placed subs...

I'm sure Mark was thinking of locating your sub off to the right rear of your room by the couch or something similar, or off to the left mid wall if possible, but I don't think thats something that you can or are willing to do...

I treated both subs as if they are one. I realize that's not ideal, but it's the only choice I really have with the equipment I have.

I don't know how well you remember my room from your one visit Patrick, but I'm pretty much stuck with the front wall or possibly behind my listening position now that my couch is far enough off the wall. Other than that, there is absolutely no room for subs of this size.

I believe Craig was suggesting the phase control could help with the subwoofer-speaker integration for 2ch music. You should probably take a separate measurement of that crossover function as well (through the 2ch preamp input).

Getting one SubMersive HP behind the listening position would likely help with the upper range, and might be worth a try. How close to the couch would the rear sub location be and how far to the front SubMersive?

He would need some significant delay, perhaps 9-10ms.... the rear sub would be directly behind the couch about 1-2ft from LP which by my rough memory I figure is about 10' from the front wall... The DCX would be much nicer for this solution over the SMS...

Agreed that a separate channel would be welcome, but how much that is needed is room and location dependent. 1-2' from the LP vs. 4+ does push those limits as you get into more of a near field condition. Of course some measurements with the sub in the back can determine if it would be worth investigating at all. It is not critical to perfectly match the arrival of each sub to the listening position, but more a matter of getting them to combine usefully. The bigger the difference, and particularly when the near subwoofer is to the side or rear, the more delay is justified. Listening will quickly indicate if it is an issue or not.

Of course a DCX is even less expensive than the SMS-1. If you already have REW functional, the benefits of the SMS-1 diminish greatly, especially where you could use all 3 inputs on the DCX for stereo input and sub input from your surround processor.

Here's an interesting one for you guys. I decided to experiment a little today. I took one of the Submersives and put it behind my listening position. Patrick is right that the sub is directly behind the couch (and LP). The couch is spaced away from the wall just enough to allow the Submersive to sit with the drivers firing along the wall. I am only running 1 Submersive for now.

Here is the measurement with my mains running:



A few things have changed sonically. Please remember that I am a 2-channel guy first. HT just has to be fun, music has to be as perfect as possible. Music has changed significantly. One thing I noticed was adding the 2nd Submersive in between my main speakers seem to dull the overall sound a bit. There seemed to be some added congestion and loss of clarity. I didn't concern myself with the issue as I thought it was just in my head. Well, now I don't. Having the sub behind my LP, my main speakers sound very open. It's like the sound stage is twice as big. There is a lot more clarity and the bass doesn't sound as thick.

What surprises me is how fooled I am that the bass is coming from my main speakers. It's amazing really. However, there is a hint that the bass is not in front of me. It seems more like it's around me, but still sourced from the front. I wonder if some time delay would "correct" this? Regardless, the bass for music is incredibly defined. Upright bass sounds so clear, I can hear the individual strings vibrating back and forth. I can hear more of the body of the instrument as well. It's VERY good!

I can also hear that I no longer have that dip in the upper bass. This may be part of the reason why the bass is so much more defined. I can't be sure if it's that or the fact the the sub is so close to me. I may never know...

Sitting here, I still can't believe how fooled I am that the bass is coming from the front, middle of the sound stage. I would NEVER guess that the sub is behind me 2' away.

I'm going to run through some movies and see how that goes...

I have my sub in the back of the room next to my main listening position. When I listen to 2ch music, the bass sounds like it is coming from the front of the room. I am fooled as well as it seems to be coming from in front of me. I guess mine would not be behind my listening position but next to it. I have it in a corner with the amp facing the wall and one driver in the corner and the other facing into the room.

Still, in the back of the room none the less. Craig and Dennis did a great job with this. I noticed that the music had more weight to it but in my mind I was not convinced the sub was on because it was not blasting. I even emailed them saying that I can't hear the sub. But when I put my hand on the cone I can feel it moving. I bet if I were to play music for someone who did not know, they would not guess the sub was on. Combined with my 1027be's I have a very complete musical system .

Exactly. If the 2 subs are up front and equidistant to the LP, then a single phase control to time align them with the speakers could potentially correct the dip at the crossover, (assuming the crossover is at or near to 80 Hz.)

If they're equidistant to the LP, then they shouldn't need time alignment with each other.

Craig

Very useful and interesting differences in line with what I have found in so many rooms. It does look like a DCX-2496 would be a great option for you as well. I don't know if you have noted this yourself, but if you sit in your listening position while a slow measurement sweep is run, in many rooms the apparent origin can "swim" around the room... even from a single subwoofer location! The reality is that the acoustic interactions with the room greatly dominate such issues. As one sub gets much closer you can get into time of arrival differences with the mains (dependent on the mains used as well) which can make for a slight pull to the rear on percussive bass. A little delay or additional low passing of the rear sub (which adds group delay) helps this perception effect. In your case of getting better upper bass from the rear sub, some delay would be the preferred solution.

Before we get into further analysis, was the measurement above taken through the 2ch preamp? Was this both L&R speakers or just one channel?

I would be interested in seeing the individual subwoofer responses at the listening position, measured directly through the SMS-1, first with the EQ disabled. 3 measurements: front sub, rear sub, combination. Don't touch the levels between measurements. Finally, which DSP program are you using (IN-1/OUT-2)?

Mark,

I have noticed a few things with the sub behind the LP. First, if I turn my head to the side, I can hear the sub itself. Looking straight ahead I don't. However, this is not always the case. At lower listening volumes, I can't hear the sub itself even if I lean over the back of my couch. It seems the issue is more evident at higher volumes. I understand using a lower x-over point and/or delay would help this.

Overall, everything I've listened to music wise sounds fantastic. I listened to as wide a variety of music as I could think of this afternoon. Everything I played sounded really great and "better" than what I've grown used to. The bass is very defined and articulate. Each bass note is just obvious and clear. The only music I played that I could tell the sub was behind me was The Black Eyed Peas. I was playing it rather loudly to exercise the sub a bit. It still sounded good, but I'll have to fix this issue. 95% of everything I listened to today, the sub's location was not detectable. So this may end up being my sub's new location with some tweaks.

Movies are different. My single Submersive in my rather large room does well enough to be entertaining. Dual Submersives is a big step up in visceral excitement. I'd say having a single Submersive near the LP is 80% of what duals brought to my normal front wall location. However, instead of just the floor and room flexing, I get a back massage as well. I don't know that I like that. What was sort of cool was how in Iron Man 2, loud explosions seemed to come as a wave from front to back. Sound wise the location behind the LP was not obvious. I'm certainly getting a lot more bang for my buck with a near field location with the Submersive.

For the sake of experimenting with the subs, I'm willing to do anything you ask Mark. Yes all of the measurements were still using my 2-channel preamp into the SMS-1 . I did have both the L&R mains running as well. I have not tried the front sub mixed with the rear sub as of yet. I EQ'd the SMS-1 for just the one sub behind the LP. As I have such a large room, I only use DSP program 2 (button out).

I will do the measurements you are asking for either tomorrow or Saturday morning. I have a pretty busy day planned tomorrow, so I may not have time. When you say you want the measurements "through" the SMS-1, are you saying you want to see it's measurements on screen or do you want them from REW? Type slowly to make sure I understand your request properly and I'll make it happen.

One last comment. I've been listening to music while typing this all out. I'm telling you in all honesty, the bass sounds just fantastic. It really is a big improvement and it's not subtle. I also just realized that I still have great bass at low volumes. It doesn't die off when the volume gets low. If you can try your Submersive closer to your LP, TRY IT!

Or just buy more of them

By the way, very nice looking room!

Thanks for the compliment. Most people don't like my room treatments. They do look a lot nicer in person though...

Mark:

I believe I have completed what you asked for. Here are the results:
(RED=REAR SUB, BLUE=FRONT SUB, and BLACK=BOTH)



And the same graph with 1/3 octave smoothing:



I think it's obvious that I'm getting a near perfect response from the sub in the rear behind the LP. The room interaction seems to be absolutely minimal. I really only have to add a little EQ to blend my mains. I am using very little EQ as well.

I also did a little playing around and I was able to lower my LP filter to 70Hz without losing anything in the 80Hz region. I could even go as low as 60Hz, but then I'd have to boost 80Hz a touch to improve the measurement. Lower the LP filter for the sub really improved my being able to tell the sub is behind me. Even when playing loud, it's really hard to detect the sub behind me even when turning my head sideways.

Listening right now with "fresh ears" as I like to call it, the bass sound from running just the rear sub is just awesome. The sound quality is fantastic. I'm also not detecting any need for further time alignment. As a matter of fact, I don't want to change anything. I think this is the best bass sound quality I've ever had. What a dumb thing to figure out after all of these years! I can't begin to tell you guys how glad I am that I tried what I thought was a dumb idea.

Mark, it appears my room was hurting the performance of your sub. The bass sounds so good now, I find myself thinking: "wow, that sounds fantastic!" more than I ever have before.

Let me know if there are any other experiments I should try. This is a rare opportunity Warpdrv has given me. I want to make certain I make the most of it!

Looking good Terry, makes me feel better to see that sub actually getting used properly, wasn't nearly using it's potential in my bedroom that's for certain.

Looks like lowering the LP filter has benefits in your case, just goes to show - ya gotta let the room decide what your going to be crossing over with to your mains after seeing measurements of the different xo freqs. Rather then blindly just choosing a XO.

Hey guys,

Without paging through the whole thread, did any of you add a SubM to your existing (other) sub setup?

I currently have the CHT CS-18.T (separate 18" enclosures run by Dayton SA1000 W amp).

I'm thinking about adding a SubM HP to these later this year among a few other possibilities. I think 3 subs in my room would be stellar.

Is it better to match what you have? Or just make sure you have a sub that will have at least the same extension of your current setup?

I like how everyone compares subs to the SubM, so I thought why not get what is the gold standard?

Very true. The room seems to dictate a lot. There is a lot of benefits to finding that magical spot for your sub. I never would have thought behind the LP would work for me.

For the record, the last time I ran Audyssey on my receiver, it came up with the right speaker distances for all of them including the sub. I re-ran Audyssey tonight, and it assigned my sub behind the LP at 5' and the main speakers at 13'.

Amen, brother! That's some sage advice right there! And the *ONLY* way to know this stuff is with measurements. My system sounds SOOOO much better since I acquired the ability to measure it. Once you can "see" what's going on in your room with your frequency response and your time domain response, you can address the *REAL* problems in your room. You can have the flattest reproducers of bass on the planet, but if you can't utilize that flatness in your room, it's worthless.

TJHUB, congrats on making the effort.

Craig

I agree as well.

I'm also glad I made the effort. It seems as it was really worth it. I almost can't wait to get some more listening time this weekend. I'm also starting to wonder what the 2nd Submersive would sound like behind my LP. I'll bet that'll approach freakin' SCARY!

gee craig, as long as you are giving away submersives, i'm not that far from you... edit: oops, i see it was warp who donated the sub...

fwiw, i have mine (only one here ) behind the listening position as well, nearfield... seems to work well for me...

Chris, I am in the same boat. One submersive near field next to the listening position. For me, it has worked out pretty good.