Dual RL-p15 D2 driver DIY..

[---k---]

Just wondering, what material are you using to judge? Can you possible attempt to discuss a little more how the sound changes. I'm still trying to learn what to listen for and all.

Also, can you post a bigger picture of your Bassis and how much did you end up paying for it?

Interesting how much amp you are using. You've got a lot more than me and it sounds like you are using most of it?

I'm not sure how much gain I am getting from the two subs and the room. I have a real bad problem that I sit in a huge peak and null and can't really move the room around. The more I run RoomEQWiz and the BFD, the closer I think I am to getting it right only to be really unsatisfied when I move to any of the other seats.

I ment to build another corner bass trap this weekend, but didn't get to it.

[steve nn]

Also, can you post a bigger picture of your Bassis and how much did you end up paying for it?

Sure. I bought it when the stereo BASSIS was a $100 off at the end of the year, so Phil gave it to me for $70 off if I recall correctly?

Interesting how much amp you are using. You've got a lot more than me and it sounds like you are using most of it?

A guy can have the drivers reaching full xmas and not even feel or hear them. I don't seem to have any problem clipping my amp now that I have the 6dB bump in headroom across the FR spectrum though. The only time I had any problem with clipping the amp was when I was running the single unit trying to measure SPL capability in a few scenes that I have used over the course of time with no EQ what so ever..

the closer I think I am to getting it right only to be really unsatisfied when I move to any of the other seats.

I'm sorry Ryan. If it's any conciliation, I would have the same problem. I focus in on my seating..lol.. well I do have a NF placement option that's good for all seating when there is a crowd, but I'm not about to move the DIY'ers. Much to heavy! I'll pull the PCi out of the den first. What page in your Thread is your room layout in by the way?

Just wondering, what material are you using to judge? Can you possible attempt to discuss a little more how the sound changes. I'm still trying to learn what to listen for and all.

I started to answer, but I needed to copy to folder. How about we start out with GLADIATOR?

[---k---]

I've seen you say $100 before, but looking at the price list on the Marchand, everything seems much more expensive. What all did you get for $100?

I saw that picture of your amp and Bassis before. I was hoping for a bigger photo.

About the amp, maybe I am confused and confusing terms. When I said that it seemed like you were using a lot of amp, it was because I thought you said that you had your amps all the way up and the receiver at like -3 to 0. This to me would seem like you've basiclly have run out of amp.

I have my amps 85% up, and the receiver at -7. If I turn up the receiver any more, I will clip the BFD.

This is basically my room, it is a little off, but...:

Image not available

I drew this up a while ago using the freebie software on the BHG website. The plants are supposed to represent the speakers. The big long table is my wife's treadmill. The wall behind the loveseat is just a pony wall. At P3 there is a poll in the middle of the room, which basiclly screw me, and doesn't allow me to rearrange the furniture. I got a big spike and null in the bottom seat. The other seats are suprisingly flat. It varies greatly 6" forward and back at the bottom chair. I can eq pretty flat and it sounds good at that seat, but at the other chair and full sofa I think I measured it to be about 3db lower. It was obvious the other night when I was demoing something to my wife. I sat in her seat, and just didn't fell the effect. It was dissapointing. The problem is never quality thoughout the room, it is quantity - I think. Moving the subs to opposite front corners didn't seem to fix the problem. I probably just need to spend more time with a test disc. I usually use RoomEQ, and I don't think I'm getting a good feel. I guess I'm going to need to buy one of those.

I'm going to hear a Contra this coming weekend. Maybe I'll have a better feel for what I should be getting after that.

[ThomasW]

The full blown Bassis kit has been $350 for many, many, years....

If one buys only assembled and tested circuit board that's $90

[---k---]

I'm reading these things too quickly and too late at night. For some reason, I got it in my head that Steve paid $100, which I know is just for the board, but then I saw his photo and was like, that is the whole kit. But, I get it now.

[steve nn]

I'm reading these things too quickly and too late at night...But, I get it now.

Yes it was late. My communication could be a little clearer also. I think many of us go wrong when we take for granted that we're on the same page. 6:30 PM to me is like midnight to most.

I was hoping for a bigger photo.

Ok I can do that.

When I said that it seemed like you were using a lot of amp, it was because I thought you said that you had your amps all the way up and the receiver at like -3 to 0. This to me would seem like you've basiclly have run out of amp.

No way brother. It's like having a 504 hemi under the hood and cruising at 45 mph. Just because it's there, doesn't mean it's being used. I can still go up to +12 on the receiver for that matter, but the input sensitivity/room doesn't require that. Like mentioned before, I never go in the red on the FBQ except when searching out my systems limit, and that's with a single unit. The EP2500 has done as well if not better than the QSC RMX 1450 I used to use with the three CS+'s.

I have my amps 85% up, and the receiver at -7. If I turn up the receiver any more, I will clip the BFD.

Is it amp or is it amps? Aren't you using the single nad?

Ryan> Correct me if I'm wrong, but it seems to me that you have concluded that you must part your subs for the best response and SQ?? No!? Maybe its more of a lack of placement options? Have you tried stacking them where P5 is? I know it's a pony wall and you would still have the love seat to deal with, but have you tried it? Your room does look challenging to be sure. I'm afraid the treadmill might have to go :E . I don't think you can expect to come out flat in all seating options (not going to happen) but you might be able to make some good progress if you, or should I say (your wife) is willing to do what it might take? Getting everything nice and flat is certainly nice but not required for good bass. Depending on your room, headroom and characteristics of your sub, a little curve can serve you quite well.

I'm going to hear a Contra this coming weekend. Maybe I'll have a better feel for what I should be getting after that.

Well maybe! I wouldn't count on it though as nice as the Contra is. You have two nice subs that need to be placed (if it's doable) differently and the dual capability utilized for headroom and slam. In your situation, I would be happy to get good response at 3/4 of your seating. That's just me talking though. You also could build a vented option and pull a driver and try it out. If you liked it, you could go dual, but I would be careful about parting them to far myself. I think that's what I'm going to do next. Not that I feel the need to as far as output is concerned, but more of a desire to have both options. My back is up against the back wall/boundary and both units are collocated along with the BASSIS, so my situation is different.. we do share in our obsession regarding subs though. I'll stop ranting and take that pic.

[steve nn]

Closer crop of the amps

[ThomasW]

Steve,

When did you buy that Bassis? I've never seen that front panel before.....

[steve nn]

I just received it a week or so ago ..I guess it was. It's also half calibrated. What seems different about it?

[steve nn]

Hold It! Maybe your playing on account of the other gear?? :P

[ThomasW]

It's twice the height of any other Marchand product. It's mono, and it's not listed anywhere on the website...

[steve nn]

It's mono

It is Mono. I think it's on their price list though if memory serves me correct?

[ThomasW]

WM8-AA BASSIS fully assembled in cabinet $ 599.00
WM8-EZK EZ Kit with manual and all parts $ 479.00
WM8-KK BASSIS full kit with cabinet, stereo, power supply, etc $ 349.00
WM8-A BASSIS single board fully assembled and tested $ 90.00
WM8-K BASSIS single board kit with manual and all parts $ 70.00
WM8-B BASSIS single bare board with manual $ 20.00
WM8-C BASSIS custom cabinet only $ 60.00

[steve nn]

Yes I just found that. So what am I looking at here then?

[ThomasW]

That's the pricing that's been there for 10yrs. And I don't see what you bought. I have a WM8-KK, it's stereo I paid $349

[steve nn]

Ok my sheet reads WM8-Mono-AA 1/2 frequency calibration.

Supposedly I got a deal, but now I'm starting to wonder. I didn't pay close to what the stereo BASSIS is, but I did pay considerably more than the board.

[---k---]

Steve,
I have a very understanding and compromising wife. The compromise we reached before I started was: either a single driver sub in the front corner or two subs in front either under the speakers or TV. I choose to do two subs, so my position options are pretty much limited. I can't put these both in the same spot, just wouldn't fly.

Anyway, I'm not unhappy with the performace. It definitely rocks. At my seat, I have to check my pants. At the other seats, it is pretty darn good. I'm just trying to understand how everything is supposed to work, supposed to feel, supposed to sound, and get the most possible out of these.

[steve nn]

I have a WM8-KK, it's stereo I paid $349

Was your kit put together. I take you had to do so?

[ThomasW]

Mine was a pile of parts...

Sounds like he's got a completely new product and you're one of the first buyers

[steve nn]

Sounds like he's got a completely new product and you're one of the first buyers

Maybe? I did tell him that I wasn't interested in putting it together myself (that's my bass you know) and that I didn't want to pay for the full meal deal either. He talked to me about mono and I felt that would do just fine. The board was a option, but I liked the idea of it coming ready to go in the cabinet for $333 that I can use with other subs I build down the road.

Mine was a pile of parts...

Are you being gracious Thomas?

[ThomasW]

Are you being gracious Thomas?

I got the parts kit where one builds everything, not the EZ kit where the PCB's are assembled and tested

[---k---]

Steve,
Would you like to do a fun experiment? I know you do.

Is there a place in your room where you don't get much room gain down low. Could you put the sub there, plot your frequency response without the Bassis, then use the Bassis to gain as much low end as possible and then plot another freqency response.

I know it would be a lot of work, but I think it would be great knowlodge to have. If you lived closer, I would do it with you using RoomEQ in about 5 minutes.

[steve nn]

I know it would be a lot of work,

No not really. All I would have to do is move myself there instead of the sub and take the readings. The union might have a problem with it, but I'll see what I can come up with? I can tell you beforehand it's going to chew up headroom, but you can actually do it yourself to a good degree using the BFD.

[---k---]

I'm just tring to see how it affects the curve, how much low end you can actually add with a BASSIS, especially below 20hz, where the BFD stops. And yeah, how much you have to turn you amp up. Some of it is just an egghead question.

[steve nn]

Well I hope your able to get to the bottom of your crackling sound your experiencing. I had intended on trying to address your question, but one thing lead to another and things took a different direction. Some of the numbers I'll be sharing are numbers I have been kind of holding on to with plans on a Thread over at AVS. After thinking about it for some time, I came to the conclusion who really gives a crap! I have other thoughts regarding, but respect keeps me from posting more. I like SVS products and always will.. nuff said..

I set out to do something with the sealed design along with being DIY,.. and I feel as though I've achieved what I set out to do. Maybe you can take this as a little pep talk in spurning you on, to keep at it, until you get to the bottom of what ever problem your experiencing?

MASTER and COMMANDER time stamp 11:04 It's when the cannon fires and rolls back at you. When the cannon hits it's stops to keep it from rolling through the other side of the ship, there is a nice LFE effect that if produced correctly gives you the feeling as if you were standing behind the cannon yourself. The dual driver PB12-Ultra/2 did a very good job of presenting it along with great SPL in what my leaky room will give up. I believe it topped out at 104 uncorrected with no eq. The dual sealed 15" RL-p's came in at 106 with a little left in the tank....no eq. I have no doubt I could coax more out of the dual PB12-Ultra's that I had after the /2, but this kind of SPL with retaining proper SQ is pretty darn good. Please take note where I load my subs though..



Image not available

In the LOTR 25 Hz ring drop, I can hit 105dB with a single DIY RL-p unit..



and in the SW II 30 Hz Fly By scene.. I can hit 111 to 112dB. A few days ago for the fun of it I decided to try dual on this scene and they did 116dB easily. 117-118 should be quite doable. The PB12-Ultras being down firing would not do this. Cancellations is all, (4-5dB gain instead of 6) due to being loaded side by side in the space I have to work with... The dual driver Ultra/2 in the 25hz tune was able to do 112dB.

Image not available

We'll investigate your question though.

[steve nn]

I'm just tring to see how it affects the curve, how much low end you can actually add with a BASSIS

My BASSIS is 1/2 calibrated, so if I understand this correctly.. I have 12dB of gain available instead of 24dB. I also need to apply the 1/2 calibration to my FS Hz knob which reads 30 to 130. My understanding is although it reads 30 to 130, it's actually 15 to 65. In setting it up, it seems to translate out with my limited understanding of the unit though.

It was about two or three weeks ago that I found the culprit of my 8dB drop at 17Hz from 18Hz. It had everything to do with my room and seating. If I move to the other end of the couch, I only get a 2dB drop. If I move another couple of ft, I actually start to gain. I suppose I could change seating to accommodate, but I've put my wife through so much concerning all my subs that I just don't have it in me to bring it up. She used to cry sometimes looking at what I've done to her nice living-room. We actually use it now (anyway) and over time her understanding has improved.

Here is what I came up for you Ryan and if there is anything you need clarified, just let me know. MV stayed constant, but I increased the the BASSIS 3 6 9 12dB. My starting point was at 0.

[Ilkka]

Hi Steve!

Please tell us more about the BASSIS? Of course boost means the amount of DC gain. Fs is the old resonance frequency. Qb is the new Q and Qs is the old Q. Am I right?

How steep is the 20 Hz cut filter?

How have you determined the Fs and Qs? From the simulation?

For $333 it's not bad at all.

[Ilkka]

Here is what I came up for you Ryan and if there is anything you need clarified, just let me know. MV stayed constant, but I increased the the BASSIS 3 6 9 12dB. My starting point was at 0.

Which frequency did you use?

It's pretty amazing that you can hit same (or little bit more) with a single 15" sealed, that what you did with Ultra/2 (20 Hz tune) or with a single driver Ultra. :T

I can make a set of new graphs if you like?

[---k---]

Yeah, I'm not quite sure what that graph is saying, but I've been a little pre-occupied to ask more questions. What is the EQ on the X-axis? And is your seat the corner loaded, and the other seat to represent the middle of the room?

[steve nn]

Which frequency did you use?

Nice to see you make it over Ilkka,

15hz.. as a afterthought I thought about if this would translate out to the same gain up higher.

It's pretty amazing that you can hit same (or little bit more) with a single 15" sealed, that what you did with Ultra/2 (20 Hz tune) or with a single driver Ultra.

Yeah I was fairly impressed with this also including the Maestro. I wish we would have graphed some lower scenes though. Hey tell me Ilkka? Time stamp 11:04, Master and Commander..what kind of LFE are we looking at here. 20 Hz?

[steve nn]

Yeah, I'm not quite sure what that graph is saying, but I've been a little pre-occupied to ask more questions. What is the EQ on the X-axis? And is your seat the corner loaded, and the other seat to represent the middle of the room?

You asked me to see what kind of bump the BASSIS could provide in a lower FR. 15 Hz being as low as my disk goes, is what I chose to use. The bottom and top line represent two different locations with the same eq (BASSIS) applied in successive 3dB increments..same 15hz tone at the same MV. The bottom of the graph shows the eq applied, but this being a 1/2 calibrated BASSIS, the numbers might be better represented by me choosing 1 through 12?

[Ilkka]

Nice to see you make it over Ilkka,

15hz.. as a afterthought I thought about if this would translate out to the same gain up higher.

Yeah I was fairly impressed with this also including the Maestro. I wish we would have graphed some lower scenes though. Hey tell me Ilkka? Time stamp 11:04, Master and Commander..what kind of LFE are we looking at here. 20 Hz?

Is it the scene where Russel yells "On the up-roll, fire!"?

If yes, here is the graph. The loudest part is around 30 Hz, but pretty much material down to 20 Hz and even below.

(between the dashes)

Image not available

BTW, (Image not available) is a nice sub killer I found today. From "Ice Age" when the icebergs collide at the very beginning. Looks like a killer 3.5 Hz scene! Who wants to try it at RL, without subsonic-filter of course?

[---k---]

Okay, with that and re-reading it, it makes sense. You were able to take 15hz from 68db all the way up to 74db at 15hz. That it pretty impressive. Do you have any idea what that did to the rest of your frequency response? I guess that is what I was thinking about. How does adding a ton of boost at 15hz mess with the rest of the graph? I'm also wondering what it does in the time domain. Everyone talks about avoiding adding a lot of boost, because you can induce ringing. But, I don't think that LT does this, I think that is the great thing about it. Don't quote me on that.

So did you have to continuely turn up your amp? I guess I'm not entirely clear on how you took your measurements (my fault, not yours). Can you walk me through it.

I may make pretty graphs with REQW or ETF, but that doesn't mean I've got this all down yet. Still trying to learn.

[steve nn]

because you can induce ringing

No most of that comes with applying to much boost along with being to narrow.

So did you have to continuely turn up your amp?

No. Maybe if you re-read what I wrote knowing MV stands for Master Volume it'll make better sense. I applied all the (12dB avalible) gain with the BASSIS.

Ilkka> I knew I could count on you. What I need is right when the cannon hits the stops, not the shot itself. I know I have a few other questions to answer, but I want to see if you can get the stops/time down exactly. nice job

Still trying to learn.

Trust me Ryan, I go through that all the time. Look back in this Thread. Thomas had to straighten me out more than once. Ilkka knows to much for his own good at times to. :lol: ;x(

[Ilkka]

Ilkka> I knew I could count on you. What I need is right when the cannon hits the stops, not the shot itself. I know I have a few other questions to answer, but I want to see if you can get the stops/time down exactly. nice job

That is a little bit harder, since there are so many "booms" on top of each other. But I managed to separate it and it looks like a 30 Hz scene. Of course since it's not a sine wave, it's not only at 30 Hz. Loudest at 30 Hz, but yet pretty strong down to 15 Hz.

BTW, the SW II Fly By scene isn't a 30 Hz scene, more like 30-50 Hz.

Image not available

[steve nn]

but yet pretty strong down to 15 Hz.

From the feel of this scene I figured it had some low content. Anyhoo it's my favorite bass scene in the whole movie. Done with conviction, it really feeds the need. Thanks Ilkka

I can make a set of new graphs if you like?

That's nice of you to offer. Maybe that would be good considering my graphs are a little lacking and in keeping with tradition. You could add the single and dual DIY RL-p to the mix along with a FR plot graph.

How steep is the 20 Hz cut filter?

As steep as it gets. With it engaged, I believe there is no bass below 20??? I'll double check and be sure though.

For $333 it's not bad at all.

Considering the FBQ2496 costs around $150, some might argue that point, but what is there to choose from and it being a specialized piece of gear (hand made here in the USA) I felt it was worth it. It seems to be a quality unit and does exactly as billed.

[Ilkka]

From the feel of this scene I figured it had some low content. Anyhoo it's my favorite bass scene in the whole movie. Done with conviction, it really feeds the need. Thanks Ilkka

Definitely. One of the best one I have heard.

That's nice of you to offer. Maybe that would be good considering my graphs are a little lacking and in keeping with tradition. You could add the single and dual DIY RL-p to the mix along with a FR plot graph.

Sounds good.

As steep as it gets. With it engaged, I believe there is no bass below 20??? I'll double check and be sure though.

An analog filter always has a slope. It can't be a brick wall.

Considering the FBQ2496 costs around $150, some might argue that point, but what is there to choose from and it being a specialized piece of gear (hand made here in the USA) I felt it was worth it. It seems to be a quality unit and does exactly as billed.

You can't do the same with FBQ2496, near but not the same. Also keeping everything analog is the way to go. BTW, are those controls variable or do they have "steps"?

[Dennis H]

Rather than buy the Bassis plus the FBQ, you can get a DEQ2496 that will combine both their functions plus much more for about $300. One of the coolest features, that I seldom see mentioned on the DIY boards is the dynamic EQ. You can tune the sub so it's flat well below 20Hz but, if the level gets too high, it will gradually phase in a filter to cut the stuff below 20Hz. Nice way to get maximum extension and still avoid bottoming the drivers. Kinda like a limiter (which it also has) but it's frequency specific -- just cut the really low stuff when it gets too loud.

[Ilkka]

Rather than buy the Bassis plus the FBQ, you can get a DEQ2496 that will combine both their functions plus much more for about $300. One of the coolest features, that I seldom see mentioned on the DIY boards is the dynamic EQ. You can tune the sub so it's flat well below 20Hz but, if the level gets too high, it will gradually phase in a filter to cut the stuff below 20Hz. Nice way to get maximum extension and still avoid bottoming the drivers. Kinda like a limiter (which it also has) but it's frequency specific -- just cut the really low stuff when it gets too loud.

Yeah, the normal BFD is so much more popular. Cheap but not very versatile.

How about this? http://www.behringer.com/DCX2496/index.cfm?lang=ENG Is it better than the DEQ2496 and what are the differences?

[steve nn]

Rather than buy the Bassis plus the FBQ, you can get a DEQ2496 that will combine both their functions plus much more for about $300. One of the coolest features, that I seldom see mentioned on the DIY boards is the dynamic EQ. You can tune the sub so it's flat well below 20Hz but, if the level gets too high, it will gradually phase in a filter to cut the stuff below 20Hz. Nice way to get maximum extension and still avoid bottoming the drivers. Kinda like a limiter (which it also has) but it's frequency specific -- just cut the really low stuff when it gets too loud.

I believe that's the second time you have made comment on the DEQ2496 Dennis. You seem to highly regard it and for reasons well stated...you know it well. If I would of had your input earlier, I very well might of went that rout?? Since I run dual collocated, headroom isn't really a issue, but admittedly I'll always opt for more...it almost always improves SQ.

are those controls variable

Yes.

It can't be a brick wall.

No not a brick wall, but a pretty good size chunk of concrete.. I'll be more precise when things (WAF) are easier to measure.

[ThomasW]

How about this? http://www.behringer.com/DCX2496/index.cfm?lang=ENG Is it better than the DEQ2496 and what are the differences?

The DCX2496 and DEQ2496 are different animals. Think of the DEQ as the Swiss Army knife of audio. And actually that's going to be the title of a tread soon to be started describing this device.... :T

I'd get writer's cramp listing everything the DEQ2496 does, here are some of the functions most people will understand

1 ) SPL meter with optional A/C weighting, peak indicator
2 ) VU meter with optional A/C weighting
3 ) Peak/RMS meter
4 ) Pink noise generator
5 ) 61 band RTA
6 ) Mic pre-amp with phantom power
7 ) 31 band graphic EQ
8 ) 10 band parametric EQ
9 ) Compressor/Expander-Peak limiter
10 ) Auto equalization
11 ) 64 user preset memories
12 ) Feedback Destroyer
13 ) Gain offset
14 ) Digital delay
15 ) Dynamic EQ
16 ) Midi interface

Now within these functions are many more features..

I just received my DEQ today, I'm sure Dennis will let us know the things I left out .... :wink:

[steve nn]

Being that my BASSIS is half calibrated, would you think that the Qb setting knob is half calibrated also Thomas? It reads .25 to 1.0 I was finally able to get to the bottom of the higher FR harshness that I had been experiencing on some material along with gaining 5dB of input sensitivity.

[Ilkka]

Being that my BASSIS is half calibrated, would you think that the Qb setting knob is half calibrated also Thomas? It reads .25 to 1.0 I was finally able to get to the bottom of the higher FR harshness that I had been experiencing on some material along with gaining 5dB of input sensitivity.

Steve,

I don't think it's "half calibrated". Like you self said, sheet reads ""WM8-Mono-AA 1/2 frequency calibration"

So I think it means "half frequency", meaning that frequency range (Fs) is only half of what is says. Only 15-65 Hz instead of 30-130 Hz. But I don't think it also applies to other settings, like Qb and Qs? If you look at the front panel, that little sticker says "Hz/2", but nothing else.

This is something you should ask them pretty fast, since it's crucial in order to achieve good performance.

Let's assume that only Fs is halved. I simulated your sub and when using 3.65 cu ft it has a Qs of 0.55 (maybe even less when accounting the filling), Fs at 40 Hz. When I look at the picture you pasted, it seems that Qs is set to 1.0 and Fs is around 30 Hz (60 Hz/2). Qb (new Q) is around 0.6.

These settings wouldn't be correct and I doubt you are getting the best possible performance with them.

Of course first we have to be certain what that "1/2 frequency calibration" means. I would shoot them with an e-mail ASAP. Then we can continue with the settings. We can even measure your exact Qs and Fs by doing a NF measurement. How would you like that?

[steve nn]

But I don't think it also applies to other settings, like Qb and Qs?

Hey Ilkka..yes, you very well might be right. We had a conversation on the phone prior to me purchasing the unit and admittedly I didn't understand (or remember) all that he (Phil) was referring to when the discussion took place. It seams as though I do remember perceiving the 1/2 calibration referred to the boost setting also?? I'll be sure to give him another call this Monday and go over this now that I have a little better understanding and get these questions answered.

These settings wouldn't be correct and I doubt you are getting the best possible performance with them.

I have no doubt about this at all. It's hard for me to understand the best way to go about getting the best out of this coupled with the FBQ. What I did was set the Qb setting to 1.0 Yesterday along with bypassing the FBQ. I viewed a few scenes afterwards and then recalibrated. This gave me a bass presentation that seamed very close to the vented designs I've experienced in the past along with nailing that high pitched/harshness I've been experiencing on some material with the new units. It really opened them up! I also took the driver out of one of the units and added about a pound of poly to the back of it along with the pound of fiberglass that already lines the walls. In the other unit I have the acoustic foam with no poly. I'm now going to add about a pound of poly to the back of that unit and measure along with listen for FR differences. As things stand now they both sound the same from the limited listening I've been able to do and come in the same in calibrating them individually.

I simulated your sub and when using 3.65 cu ft it has a Qs of 0.55

You figure each of these are coming in at around 3.8 after factoring for bracing, extra baffle panels and the driver.. maybe closer to 3.9 cu ft.

We can even measure your exact Qs and Fs by doing a NF measurement.

Anything that'll move me forward in my bass qwest would be much appreciated. It was you who recommended these drivers to me in the beginning.. after yesterday, I'm especially glad I listened! These things are a hoot! Of course SPL is a big factore and always will be, but SQ is just as important. Once I get that totally dialed in, these will be my final bass producers. :rofl: :rofl: :rofl:

[Jack Gilvey]

Sounds like he's got a completely new product and you're one of the first buyers

Yeah, cool! It used to be that a mono Bassis would have the same chassis as the stereo. Nice price, too. Does the DEQ2496 have shelving boost?

I'm pretty sure that the "Hz/2" merely halves the Fs, making the range 15-65Hz, this was the option decribed to me. I can't imagine why it would be "half-calibrated" any other way, halving the boost, Q, etc., I don't see the purpose of that.