I posted over on DIYMA and finally got answers.

I always thought when dealing with sealed or IB systems, output would be excursion vs cone area so it made no sense why people would say that IB is not as loud as sealed. In fact IB has the potential to be louder in the really low frequencies.

Sealed requires more power to hit the same SPL while IB requires much less. So when people saying IB sucks because it can't handle as much power, it's actually a very good thing. It can't handle as much power because the subs are able to hit their full excursion with much less power. The differences seem to be less at higher frequencies and greater at lower frequencies. Since the sealed box acts as a high pass filter, the IB can really stretch it's legs at the lower frequencies with very little power. In order to get the full power potential from IB, a sub sonic filter will be required to avoid damaging the subs. IB is not as idiot proof, much easier to damage subs as I have almost done several times. In fact I got to test the 15s suspension a little harder than I ever wanted the other day while goofing around on a 7hz test tone.

The thread: http://www.diymobileaudio.com/forum/...ib-output.html

I got to thinking about this when I was playing my 2 IB15s up against another guy's pair of 15s in a large sealed box and mine gave up nothing in output. Just another reason I will never go back to sealed in this particular car.

 

HA...I was just talking to my box builder about IB since i need to get that damn gti in my moms car and he told me essentially the same thing.

he said....

Maximum output is the same as sealed because peak output is limited by the same factor; peak linear displacement. So the output potential isn't any lower with drivers mounted IB compared to sealed. The difference is in the response curve. Sealed enclosures will usually have a little more output in the upper-subbass (above 40hz) due to the peak generated by the affect of the enclosure.....however, IB drivers will typically have more output in the lower frequencies (40hz and below) due to the lack of enclosure (a sealed enclosure is essentially a highpass filter(as u said), so if you remove that you improve low frequency response). Mechanical power handling is reduced for a driver mounted IB since it doesn't have the "spring" of the enclosure to aid it mechanically.

simple version:

You dont lose power handling, you lose power requirement. An IB sub is just as loud as sealed assuming the same FR response. What changes is FR, a sealed box raises the midbass (depending on size) making it "louder" but simply EQin for the same FR would make it the same SPL but requiring less power to do so.

 

I wish any local shop knew as much as your guy. A couple guys from work that have heard mine were looking into IB. 3 different shops said there's no such thing, it can't work and if you tried it, it would sound terrible. IB had to be described to them, they didn't know what it was. I plan on taking mine to those shops, ask them about installing an IB setup, let them tell me it won't work and then letting them hear mine without telling them the setup.

 

So just a thought- Doesn't the acceleration matter? A sealed system can use much larger motors and higher power without worrying about reaching xmax. That means it can probably accelerate the cone harder. Wouldn't that affect something?

 

It matters but acceleration will be a constant at the same frequency with the same excursion. If you take two subs with a 20hz tone and drive them to 20mm excursion, they will have the same acceleration. They will be moving the same distance and reversing direction the same number of times per second. If you increase the acceleration on one of them, it will either be playing a higher frequency or it will have more excursion.

A sealed box requires more motor and power to overcome the air spring of the box. IB requires MUCH less power to reach the same excursion because there's no air spring to overcome. I've been modeling sealed vs IB all day and the only difference I can find is on some cases the sealed boxes show a tiny .5-1db bump between 40 and 70hz and level out again while the IB setups show 4-6db more in the lower frequencies at the same power level.

The sealed box acts like a high pass filter so it's harder to hurt the subs from over excursion if you're not using a subsonic filter but IB is just so much more efficient in the low end.

Knowing my subs hit xmax at 20hz at around 150w, it's truly a win-win situation. How many setups do you know of where you can hit xmax on a pair of 15s with 150w each?

If you take my two subs and put one pair in a 6cube box and the other pair in a 15.5cube trunk, at 20hz it takes 500w on the sealed setup to produce the same SPL as the IB setup at 150w. Now after 20hz, the higher power sealed will start getting louder but down low, IB has a ton of efficiency advantages and up high you don't need as much power.

 

I think one reason IB has fallen out of favor with people/shops/manufacturers is the whole power thing. It is easier to sell uneducated people that their sub can handle 3000 watts (peak) and 1500 watts (rms) and then sell them a class "D" amp that can deliver that power without destroying the cars charging system. Marketing!!! Then you can go and brag to your buddies about how many watts you have. I would take an IB setup and 400 watts any day of the week and it would sound tons better and hit just as hard! Now about Aperiodic Membranes....

 

Shops are in business to make money. It is easy to drop in a square box, make a profit, turn a happy customer over and move on to the next guy. It takes a special kind of customer to want to spend the extra money and time to make IB work correctly. As a businessman, I can see why they would shy away from it and turn and burn a higher margin product. People do like to measure the size of their cranks, though... and 3000W does sound good to some. ...and most people who come in are less than educated, or they would not likely be paying retail with so much of a discount offered on the internet anymore.

From my own experience, I would also qualify this by saying that a low quality setup of either would get blown away by a high quality setup of the other. With my "normal" T1, W6 and WX33 drivers played in IB, the high powered sealed crushes them in sound and output. However, none of these "normal" subs were made for IB and I do have a sub made for high powered sealed, so this is about what we should expect.

The AE and FI 15s should be here soon (f'ing backorder) for some better tests. I only ordered one of both - I hope that I don't regret this, but I have enough unused subs laying around.

Maybe I am getting old, but most of this has ceased to matter to me over the last months. If I can hit 130db, then I am happy anymore... and most any setup can do this with a medium effort.

 

I fully agree! IB is soooo much more power efficient down low over sealed. It's almost funny how the fact that it requires much less power to reach the same SPL is deemed a negative. I always see "less power handling" in the con list of an IB setup when it should be "less power required" and on the pro list. The people that have demo'd mine usually want the bass cranked (very few like SQ unfortunately) and most are usually impressed and ask me how much power I'm feeding them. I'll reply with about 250 each and less than 100w for SQ listening and they don't really know what to say.

I've got to hear your Dyn in IB one day. I go back home to the Gulf Coast fairly often, I wonder if it would be possible to get a layover within driving distance?? That's one of those subs that I can't get off my mind. It's almost like I'm going to have to try one, one of these days.

 

I applaud you for getting out and trying different subs. At least when you disagree with me, it's from experience so I can't really say anything negative towards it.

I also don't really crank the bass much anymore. Usually it's only when someone asks me too. In daily driving it gets old quick and I have it at a more SQ oriented level. Just enough to overcome tire noise at speed.

Looking forward to your review of the IB15. I know you will love it. Please try it with a low pass of at least 100hz and a subsonic down to at least 20hz to see what it's really capable of. It's just incredibly musical. If you don't like it, you can sell it for more than you paid and it will likely be gone within hours of putting it up. Is this the IB15 or and SBP15?

 

The SBP. I got a single 15. I have never thought that all the data coming from AE was 100% legit and seemed too self serving, so rather than being a whiny pussy about it, I decided to try one for myself. Right or wrong, nobody needs an armchair quarterback.

The IB3 has an xmax of 30mm compared to the SPB 18mm. I cannot wait to see how that plays out.

These 2 will make 14 subs in my building not being used. I need to sell them and buy 4 post lift.

 

I'll gladly take the SBP15 off your hands if you end up not using it...

 

I reread through that post that you started at DIYMA for a third time. I think that I finally get it. I never thought of SPL as energy dissipation before. I always understood that trapped waves in a box would react with the cone and surround, but never thought of it as energy. That is the best thread of my year, so far. Thanks for the link.

 

No! Mine!!

 

I think it's worth about $500.....

 

Thanks. This subject has bothered me for a while because I never fully understood it. From the best I can gather, the .5-1db boost in the 40-100hz range of a sealed box is from the backwave but could be considered distortion.

I think the IBs got the reputation for not being not as loud because number one, the power requirements are so low and number two since they can't take as much power in the really low frequencies you have to be smart with a subsonic to be able to feed them their full thermal rating across the board. If you ran them like many people without a subsonic set up right, you would have to limit power down low to limit excursion which would limit power across the board in the higher frequencies.

I've got mine set at 20hz/6db but I still get quite a bit of really low stuff, even some 7hz stuff that makes them go crazy. I wish the MS8 offered a 15hz filter so I could step the slope up to a 12 or 18db. I keep it so shallow because it interferes with the lower 30hz stuff as it is. The song "Put on" has a 27hz note and it's not quite as strong with the SS filter. It's in that range the you can feel but barely hear anyway but I like the impact of those lows.

Have you actually ordered the SBP15 yet? If not, the 3 of us should get in on the 4 or more deal.

 

I ordered mine already.

My experience with the non-ib oriented drivers is that they are nowhere near as loud as the sealed driver. However, this is like apples to cars becuase everything was setup near-perfect for the Q and the IB setup is nowhere near perfect.

I don't think that most models are set up for IB, but I could see how it would model out at -.5.

I have do have some thoughts after reflecting on this, but I will post those out on DIYMA so that the smart guys out there can weigh in.

The FI is in the mail. Should be here tomorrow.

I also am collecting my supplies for my test with the FI and SPB:

• DVD-A Test Tone CD
• New-to-me refurb factory radio from OEM Car radio where the CD/DVD works
• Cheap SPL Meter - don't make fun of me, it should work for my test
• Oscilloscope on loan from a friend to accurately measure wattage
• Maybe a day tomorrow where the temp is under 103 and humidity under 80% and I can put the new radio in. It was 109 yesterday - real temperature.
• Less powerful D class amp for the IB subs - I have plenty of AB, but I wanted to go D to D.

 

Looking forward to the results. You'll see how lots of motor strength is not needed for IB. Those Fi subs have less motor strength than the IB15s and especially the SBP15s but I'm sure they sound ok.

I can't wait to show how much more efficient IB is watt for watt and how it will hit the same SPL up high and even more down low.

 

From John at AE:

"All the IB's have the same coil so power handling is the same. Thermally they will have no problem with 500W. However, when used in an infinite baffle, you're going to need only around 100-150W to move them to Xmax down at 20hz. This is one of the big benefits, that you can get loud without all the thermal issues you have in small sealed enclosures. In reality, 200-250W is a good range for the IB woofers."

IB15 vs IDMax http://www.diymobileaudio.com/forum/...omparison.html

IB15 vs Fi and Dayton and IB in general http://www.diymobileaudio.com/forum/...ib358-8-a.html

 

That quote from John is from last year. Does the same apply to the new sub?

Do you know of any threads that have in-car tests and not models and anecdotal observations? ...and not from any particular manufacturer talking about their own stuff? I realize that even few of these exist for long-time used setups, like ported or sealed, but I thought that I would ask. Did I mention that I am an non-trusting dogmatic dinosaur?

I borrowed an oscilloscope and already had some resistors to measure output of my T1500 at every notch on my HU volume. I will probably roll up to 35. I will have real wattage for each test. However, I don't care too much about watt per watt, rather overall driver per driver or setup per setup. I will think of these results in terms of what to do in my next car holistically, and maybe this car if I am blown away. Wattage is just one piece, but anything under having to upgrade stock electrical is not a huge deal for me, although it may be for others.

I bought at T500 for driving around after I measure. This way, that I can set the stage up OK for listening. The T1500 blows past assumed 250 watts too quickly even with the gain all the way down, so while it will provide an excellent SPL test, it will overpower the sub in regular use in regards to the rest of my stuff. I struggled with this using the "normal" subs in there, but I had pairs of them so the wattage was higher.

I suppose that I should seal up a 15" FI Q, instead of my 12", and see how that stacks up with the same cone area, but since I have enough subs and no need for lots of SPL, I will not spend the money or time.

 

One of the above tests had the in car response of the IB15 at 3 different SPL levels basically showing they're extremely flat with no eq and freq response doesn't change as you go up in SPL which is noticeable in mine too. I think it was the IB15 vs IDMax but I may have to search again if that's not it.

 

This response over at DIYMA really explains it well, probably the best post in the thread courtesy of "Sqshoestring":


"I missed this thread. Bikini hit most of this, but the big reason sealed is 'louder' than IB is because people are talking about SPL frequencies. You have Q or tuning of the sub, and then you have frequency played on it. The box pushes Q up and causes a bump in response (likely your .5db), usually right where you want max output. The sub has been tuned to like that spot; the air spring in the box is tuned with the mass of the cone like the frequency a bell rings at. Given most subs are made to suppress a particular frequency from peaking in the response. This makes it easier for the sub to play that frequency, lets say 50Hz. Why 50, well because most subs can play that really loud without needing much xmax. When you go lower you get limited in output by xmax...the sub will never be able to play lower frequency as loud no matter what because it can't displace more air. Pro systems play loud with larger drivers and low xmax because they are cheap and work well that way, they don't care about large boxes....but they never play that low where xmax starts to matter. They use horns to boost low end without need for big xmax.

The box and IB will be roughly similar in max output at lower frequencies limited by xmax, but the box will require more power to reach xmax as well as more EQ boost to get as flat a response as the IB. It also fills your trunk.

Why go with more cone area IB? More output to start with, but on top of that xmax is a huge problem it makes the sub distort. Sure you can get expensive subs that do not distort at big xmax, if you want to, but they tend to have worse specs for IB including inductance, inefficient, expensive, low qts that gives more rolloff on the bottom, etc. They can work, but if you put a baffle in why not fill it up with the largest you can fit there is no negative in that excepting a couple inches more motor height. Plus odds are you get a driver with a lower Fs that will play lower, it will have more output, more output at less xmax/distortion, just because it is larger. I went beyond that and ran cheaper 15s because I could fit them but figure I didn't need the output of a big xmax 15 in a pair (say the AE IB15 I really liked). Even these pyles showed over 1" of travel in a test before I mounted them, on a 170rms amp and sine tones. So I figure if I use half that it should be pretty low distortion, indeed output is large on my scale at .5" excursion. On the other hand if you want to get something around 20Hz you need to move some air so going overboard is good for that. Quote:
Originally Posted by BuickGN
It's obviously not a true IB in a car. Opening the trunk on a couple of my setups like the 12w6 and Tempest X resulted in a big loss of bass. With the IB15s, there's hardly a difference. The one thing I never tried was with the doors and windows closed, hitting the trunk release. I always had the doors open when I hit the trunk. Not sure if the rear wave could cause cancellation or not in that scenario.

Mostly it depends on the Vas of the subs. If you are approaching Vas with your trunk it will start to act like a box and roll off the bottom, push up the Q. You will hear it when you open the trunk. If you model a sub at vas (say your trunk is roughly total vas) and then at 10X vas you should see the difference you hear. My 15s are 5cf vas and 15cf trunk, so I am at 1.5X vas. If I model that and compare to 100cf I am losing 1dB at 20Hz and the rest is the same. I can't really hear that difference considering not many notes hit 20hz or hit it strong enough to be fully aware of it. But if I change 20Hz on my EQ it certainly makes a difference with a lot of music. Next on the EQ is 31Hz so it might affect response up to that not sure. It is hard to hear a tone under about 25Hz in my car but I do feel it. Trunk open is no or only slight difference but some stuff in the trunk will start to roll it off.

When I had quad infinity 12s in my car IB it would get really loud at 50-60Hz. I had to EQ and double xover to cut it down near flat. They had Fs 24 and qts .46 (kind of low for IB) and that caused a rolloff on the bottom. I only had 420rms on them and if I didn't EQ and turned the low pass to 80 they would near blow me out of the car at 50. So you can make a SPL type IB system, or close to it, if you use the right subs. These 15s have near the same specs as the AE IB15s and need nearly no EQ to play flat, very impressive bottom maybe the best I have had in a car. But my goal was SQ low as I could get, pretty flat not needing big EQ, would go loud enough to feel it. I have taken out a 500rms amp and put in a 350rms, jury still out but it is not bad this way for my use I don't need to shake the roof of the car really and it overwhelms the mid/highs. Also when I had the 12s in I used a PEQ on them finally to get some control, did not have the 16 band right away. It was awesome I could make those subs sound any way I liked and am seriously considering putting it back in. It worked better than the 16band no doubt, for the subs. The 16 only has 20/31/50/80Hz in the sub range, so I would very highly recommend a PEQ on IB subs if you like to change how they respond. I used an old alpine that only worked under 200Hz. But these pyles sound so nice I'm not in a hurry to find a place to mount the PEQ again"

 

Almost forgot, the IB12 on the Klippel 3rd party testing by Matt at Image Dynamics: http://www.diymobileaudio.com/forum/...-ib12-8-a.html

 

A layover in Omaha (epply) would be 10-15 min away or possibly KC, 2 1/2 hours (3 now with the flooding).

 

I thought IB installs were just too difficult. Having to seal everything up, every little hole, just seem like a huge hassle. With the small airspace requirements of most of todays subs, the space saving is minimal. And lets be honest, if you are running 2 15" subs, you are not saving that much space over conventional sealed boxes, just opening up the driver to potential harm.

 

Reeeaaallllllyyy.....and what do you think those small boxes do to the frequency response???? You don't need to seal every little hole, just most of them and all big holes. Lets see.....a single baffle board vs at least a 2-3 ft^3 box for 2 15" subs. We are talking having a trunk vs not AND better sound AND less power needed to make the sound....how is a small enclosure better again???

 

You don't have to seal every little hole, just the large ones and it takes about 30 minutes to seal everything. The baffle takes less time than a sealed box to build. You have to figure out how you want to attach it to the car and how you want to build the baffle since there are several good ways. None of it is hard at all. Figuring out how you're going to install a 3-way front set or even fitting an aftermarket 6.5" in the doors is just as hard if not harder than going IB.

So you're saying a 15" 7" deep sub like this is taking up more space than your typical sealed or ported box?



How is the sub exposed to any more danger than subs in a sealed or ported box? The cones are protected behind the seats instead of the normal rear facing boxes with unprotected cones and all that's exposed is a cast aluminum frame and magnet, neither of which are easily damaged.

Subs in small boxes require at least twice the power for the same output. Any given sub in IB will require around half the power to get just as loud so power requirements are way lower. Put it up against a sub in a small sealed box and the difference becomes even greater.

Let's not forget, IB just about always has better SQ all else being equal, requires half the power, will dig deeper and won't get into resonances in the upper frequencies like sealed will. Then you have space savings. You take up about as much trunk space as a single 10" in a small box.

No compare that picture of my two 15s and let's look at some other TL installs from 6.5" to 15"...

 

IHC and others. I really want to go IB due to space and such. I do like to feel the bass but I think SQ is where I would like to be. More so than SPL anyways. My question is I am at a stand-off as to which woofer to get. I have seen the numbers but it is french to me. I know the Dayton is the less of the 3 when compared to AE and FI. But is it half as good? because the Dayton is $127 and the FI is @ $200 and the AE is over $300. Any help or suggestions will be listened to.

 

Usually when it comes to audio, if you pay twice as much you might get a product that's 10% better. Maybe not that bad but rarely will twice the price equal twice as good or even 50% better.

The specs are important but even better is knowing someone who has tried the sub you're looking at and know it will sound good IB.

I did the 12W6 against the advice of many and it was just about the best setup I've ever heard in IB.

I did the Tempest X knowing it's roots as a home theater sub and even though many said it would sound good, it sounded like the stereotype many people give large subs. Bad transient response, overwhelming low end with no high end punch. Just lazy and "slow" sounding. I'm sure it was great for what it was designed for which is home theater and the 10-50hz range with tons of air space.

The AE IB15s with somewhat similar specs to the Tempest are THE best sounding sub I've heard. They go against the large sub stereo type with bass so tight and quick that you would think there are a pair of high end 8s or 10s back there but with effortless low end. And by low end, I mean they reproduce frequencies with ease that my sealed setup could not produce at all. The fact that they combine all of this together is what makes them so nice.

I don't know what the Dayton would sound like in an IB. I hate to say it but sometimes you're stuck listening to others' reviews and just trying stuff out for yourself. Make sure the people giving advice have actually heard the sub in question and are not just repeating what they've heard on the internet and guessing. Listening to people like this even on a very good car audio forum is what made me almost miss out on the 12W6 IB but I decided to go against the majority since I got the feeling they had no first hand experience and I am very glad I did.

Since IB subs will xmax very easily in the low frequencies with little power it's always a good idea to have a fair amount of excursion available or use multiple large subs. I prefer as much cone area as you can stuff in there over tons of xmax. At moderate listening levels you can't see the 15s move, even on the low frequencies. About the only time I crank it to the point of being able to see them move is when people ask me to. With such little excursion, they're more linear and have less distortion. This is especially beneficial on cheaper subs that tend to have lots of distortion with lots of excursion. You can level the playing field somewhat with a couple large cheap subs that don't have to move much over a more expensive sub that has to work harder.

 

And I'm like !!!

 

Not likely that you will find somebody who has used the Dayton, Fi and AE. I ordered the AE and Fi to try out, but who knows when the AE will come. I don't even know if you can order the AEs right now.

If you are going to spend twice as much money, it needs to be for a specific purpose IMO. Twice as much money on a generic sub probably has a poor ROI, but twice as much for something that matches exactly what you are trying to do is fine.

If you are going to do IB, then get an IB driver. If you must use a non-IB sub, then 15" would probably be best.

 

IHC.. what are the dimensions of that wood piece? Or what do u recommend? I'm about to try it.

 

I don't believe he has the dimensions. Best way is to just find a large piece of cardboard and cut it until it fits in there nicely and bam..there's your template.

Use 3/4" MDF and double it up. If you're using 1 sub, it's easy to mount the baffle to the rear cross bars behind the rear seat and call it day with the sub mounted between them. Check out Neibur3 (jerry) install for pics. With 2 subs....I don't think this is possible

 

Here's a few pictures.

From inside, I should have rotated the picture before uploading it. I used a flash, the material is black and matches the interior perfectly but not with the flash on.

An older pic of the subs with no cloth to hide them before I removed the plastic to open up the hole a little more:

Here's the long top bolt I used to hold the entire assembly in place since I didn't have a helper. I left it there as added support. The top brackets are hidden by the cross braces.





As I was putting the carpet back in, I forgot to put the top piece of carpet in and the sides were not screwed down yet so they're a little crooked. The "vanity" cover is also off that hides the subs. The car just got rained on as well. It's usually dirty but not this dirty.

 

Is the wood rectangle or custom shape? Any measurements?

Also, I wonder if it it is necessary to use MDF since there is no enclosure..?

And I wonder about removing the back cover of the seat. Is it possible? I have not looked at it that closely with the seat out.

 

It's mostly rectangle with the top corners angled down to match the car. There's no one size fits all. If you use a single sub that will fit between the braces, it's easier to attach the baffle to these braces. If you run two subs, I can't see any other way but to attach the baffle to the chassis and the baffle will be slightly larger.Really all you have to do is get close and then seal it up after it's installed.

The seat helps to keep a lot of noise out of the car. I ran it with the seat out for the first week to keep an eye on excursion. Road noise was noticeable. After putting the seat back in, I couldn't tell a difference in output of the subs but I could hear a good decrease in road noise. Even with the trunk sealed off and seat in place but without the trunk carpet installed, there was more road noise. I can only assume it was getting through the cones of the subs but that's only a guess. I added a little additional vibration mat and sound barrier in the trunk along with the factory carpet and it helped. The factory put sound barrier on the back side of the factory trunk carpet so they knew that noise can enter the car through the trunk. This is why I wouldn't remove any seat components.

With the armrest up, the sub bass gets through ok. If you play your subs up higher like I do, around 90hz, the armrest does block some of the upper frequencies. If you cut them off around 50hz, it doesn't make a big difference with the armrest open or closed.

You need a material that's going to damp vibrations. MDF is pretty dense and does a good job. You want a minimum of 1.5" thickness. While I don't listen to mine that loud very often, when I decide to crank it, a pair of 15s with 1,670cm2 of surface area moving 2" will put the baffle to the test. And of course, the trunk has to be sealed from the cabin or you will get cancellation.

 

So for your IB setup you used two 3/4" mdf boards and stuck them together? Did you cut your holes for your subs through the boards the same size?

 

Luckily these subs had very "easy" dimensions so I had the baffle made before they arrived. I did one with a 14" holes that the subs front mounted to and the other with 15.5" holes that went around the subs. Additional bracing was added later on.

 

For the love of all TL's alike... GAWD WASH THAT CAR!!!...LOL! Just messing with you... Nice work!

My only rookie question is, any cancellation of sound with the 2 15s side by side firing fwd and only 1/4 of each woofer from free flowing space in front when all installed? I am sure others ask the same wquestion. Just seems to be "muzzled" if you catch what I am saying.

 

Lol. It was under covered parking and the runoff from the rain was right on the rear of my car. It rained just enough to cover the car in mud.

No problems with the subs close to the seats. There's about 2" from the subs to the seat back. If they're run from 50-60hz and down, there's very little difference with the armrest up or down. I like to run them higher, at 90hz and it does block some of the higher frequencies with the armrest up.

I've run them with no rear seat for a week and there's no audible difference between no seat and the armrest down. I've even run them up to 2,200hz and they played female vocals like that just fine. Bass is sharp and tight when needed but also VERY low and powerful when needed. Right now they blend so well with my midbass that it's hard to tell what's coming from what speaker.

 

Did you just use screws to hold the two mdfs together or was there any adhesive involved?