# School me on infinite baffle



## jbowers (May 3, 2009)

I'm thinking of going IB on my new build, but there's one question I don't think I've seen answered in the threads I've searched. My new Audi A4 seems buttoned up tight as a bank vault with the rear seats up. Very sturdy metal seat backs that seal up extremely well. How do you overcome this in an IB configuration?


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## mires (Mar 5, 2011)

jbowers said:


> I'm thinking of going IB on my new build, but there's one question I don't think I've seen answered in the threads I've searched. My new Audi A4 seems buttoned up tight as a bank vault with the rear seats up. Very sturdy metal seat backs that seal up extremely well. How do you overcome this in an IB configuration?


You don't overcome it. That is exactly what you want with IB. Consider yourself lucky.


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## jbowers (May 3, 2009)

mires said:


> You don't overcome it. That is exactly what you want with IB. Consider yourself lucky.


Huh. I was concerned with losing too much volume between the cones and the seat backs. In my Jetta I cut and reinforced the rear deck to vent the delicious bass into the cabin, it had a similar configuration but I know that's not an option with IB. Huge difference in volume between seats up and down before I ventilated it. I also won't be able to pour on the extra power without releasing the magic smoke. Am I just over thinking it?


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## mires (Mar 5, 2011)

jbowers said:


> Huh. I was concerned with losing too much volume between the cones and the seat backs. In my Jetta I cut and reinforced the rear deck to vent the delicious bass into the cabin, it had a similar configuration but I know that's not an option with IB. Huge difference in volume between seats up and down before I ventilated it. I also won't be able to pour on the extra power without releasing the magic smoke. Am I just over thinking it?


If I'm understanding you correctly, I think you are overthinking it. IB is basically a large leaky enclosure. You definitely don't want vents in the rear deck like it sounds like you did with your previous vehicle. The goal is to try and seal the trunk off from the cabin as well as you can.


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## req (Aug 4, 2007)

Loudspeaker enclosure - Wikipedia, the free encyclopedia



wikipedia said:


> Infinite baffle[edit]A variation on the 'open baffle' approach is to mount the loudspeaker driver in a very large sealed enclosure, providing minimal 'air spring' restoring force to the cone. This minimizes the change in the driver's resonant frequency caused by the enclosure. Some infinite baffle 'enclosures' have used an adjoining room, basement, or a closet or attic. This is often the case with exotic rotary woofer installations, as they are intended to go to frequencies lower than 20 Hertz and displace large volumes of air. "Infinite baffle" or simply "IB" is also used as a generic term for sealed enclosures of any size, the name being used because of the ability of a sealed enclosure to* prevent any interaction between the forward and rear radiation of a driver at low frequencies.*


utilize the rear deck to mount the speakers. this is the easiest way to do this.




























B6 A4 *Magic Bass*

















use your imagination 

i prefer to mount a piece of wood to the BOTTOM of the rear deck. use rivet nuts to affix captive threads to rear deck, align these with a wood panel. fill any gaps between rear deck and wood panel with gasket material, cut holes for speakers, affix speakers to wood panel with bolts, washers, lock washers, and T-nuts.


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## jbowers (May 3, 2009)

I was hoping to avoid cutting this one up like the Jetta, but that might be an option. Aside from the AE subs, what other high efficiency IB suitable subs should I be looking at?


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## kaigoss69 (Apr 2, 2008)

Ski pass.


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## jbowers (May 3, 2009)

kaigoss69 said:


> Ski pass.


If only the car was so equipped. I've entertained the idea of buying the RS4 Recaros which do have the ski pass (along with the sweet Recaro buckets up front too). Otherwise, I may just cut out the seat back behind the rear center armrest. The idea was to be able to retain trade-in value, but then it's never worth what you want for it anyway.


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## BuickGN (May 29, 2009)

One side of the cone must see the cabin and one must see the trunk. 

The AEs are one of the best all around subs I've ever run. They do everything well. 

I'm running a pair of ID Max15s now and they are great. They sound great, blend easily, can be gentle and detailed, and get absolutely brutal when needed. 

You can do a smaller diameter high excursion sub if you don't want to cut much like the 12 or 13W7 which sound great.


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## jbowers (May 3, 2009)

If I'm remembering the threads correctly, with a smaller trunk a single IB15AU would be appropriate, or a pair of SBP15s, correct? And would it be worth the extra expense of doing the pair of SBPs for the extra power handling and cone area, or are we talking maybe a 3-6 db difference in output? 

I'm so used to thinking in terms of standard enclosures, so you guys with the IB experience are going to have to help me change my way of thinking.


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## BuickGN (May 29, 2009)

The IB15 has less motor strength so it would be best suited for larger trunks or in singles. Since the SBP has more strength, Qtc will not be affected as much by smaller trunks or in multiples. 

In reality I don't think it makes much of a difference. I had a pair of IB15s in my 16 cube trunk and they were great. If you had a really small trunk and wanted a pair the SBP might be the better choice. 

In my opinion it's worth the pair. Not only do you have the potential for double the output with double the power but you cut excursion in half for a given output which is good for SQ. The pair of mine rarely had more than a few mm of travel.


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## jbowers (May 3, 2009)

I can't argue with that logic. Would you say the Apollo option is worth the money as well?


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## iroller (Dec 11, 2010)

Buick GN, I know you have used dyna's would one 12 work in a large trunk IB 68 impala looking for SQ.


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## kappa546 (Apr 11, 2005)

req said:


> Loudspeaker enclosure - Wikipedia, the free encyclopedia
> 
> 
> 
> ...


That's what I did in my jetta. I know exactly what you mean by the hard metal back seats. The rear deck is the only way to go IB in these cars. I'm running a single AE IB15 in the middle of the rear and it just barely fit, no way I could have fit two as the deck narrows to the sides. One is plenty for me though.


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## BuickGN (May 29, 2009)

iroller said:


> Buick GN, I know you have used dyna's would one 12 work in a large trunk IB 68 impala looking for SQ.


I think the Dyn subs are the only Dyns I haven't used, at least in the Esotar line. I've heard a few sets though. 

The 1200 is commonly run IB, I think I've seen more IB than any other way and they sound great. I've seem the older MW190 run IB and in a box as well. Which one do you have in mind?

As for one being enough, output will be similar to the same sub in a sealed box. With a single 12, I can't see there being an audible difference between an average sized trunk and your huge trunk. Maybe with a pair of 15s with a huge Vas but not a single 12.


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## HardCoreDore (Apr 30, 2014)

So Infinity baffle is basically free air? I thought IB involved woofers firing into these disk type things that cover the cones of the woofers. 

I obviously don't know much myself...


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## kaigoss69 (Apr 2, 2008)

Displacement is the key. You can get away with a single 12 or 15 as long as it has enough xmax to generate the volume you want. Not any driver will work, but surprisingly many do. I would stick with what we know works well though - ID Max, JL W7, and AE, for example. I'm running a single ID Max 15 through the ski pass and I could not be happier. 


Sent from my iPad using Tapatalk


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## jbowers (May 3, 2009)

As much as I think the deck mount is probably the better solution, I'm just really averse to cutting that much metal. If I can get the ski pass cut out and make it look OEM, that's probably the best compromise. 

Now I've got to get serious about planning, hopefully I can find something in the classifieds to get started.


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## jbowers (May 3, 2009)

HardCoreDore said:


> So Infinity baffle is basically free air? I thought IB involved woofers firing into these disk type things that cover the cones of the woofers.
> 
> I obviously don't know much myself...


I believe you're thinking about aperiodic membranes, which create kind of a leaky enclosure. What that does is lets the woofer perform as if it's in a much larger enclosure by letting air move through the membrane slowly. I've read up on them and it's something I'd like to try one day, but you either need a lot of patience or a lot of previous experience with these types of setups to get it right. 

Infinite baffle is basically using your entire trunk as an enclosure. It's much more efficient than a traditional enclosure, but you have to be very careful with power levels as it's much easier to kill your sub due to over excursion. With the right setup though, it's fantastic.


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## HardCoreDore (Apr 30, 2014)

jbowers said:


> I believe you're thinking about aperiodic membranes, which create kind of a leaky enclosure. What that does is lets the woofer perform as if it's in a much larger enclosure by letting air move through the membrane slowly. I've read up on them and it's something I'd like to try one day, but you either need a lot of patience or a lot of previous experience with these types of setups to get it right.
> 
> Infinite baffle is basically using your entire trunk as an enclosure. It's much more efficient than a traditional enclosure, but you have to be very careful with power levels as it's much easier to kill your sub due to over excursion. With the right setup though, it's fantastic.


I was thinking about aperiodic membranes. I remember they became really popular in the late 90's competition scene. I've never had a chance to study the design, although I have heard it's a ***** to get right. 

So infinity baffle is basically "free air" I guess. Unless there's a difference their too.


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## 14642 (May 19, 2008)

For infinite baffle, the most important consideration is the amount of power you'll apply and the length of the voice coil (Xmax). You won't have the additional protection from overexcursion that you'd have with a sealed box. 

Compared to the Vas of just about any car audio driver you have to choose from, the trunk is HUGE and isn't going to contribute much to the shape of the rolloff. 

Sealing the trunk is overrated. Completely sealing the trunk is overrated. DO NOT go squirting expanding foam between the body panels, etc. In addition, if you take the trim panel off the top of the rear deck and you see a bunch of holes (usually the metal part of the panel isn't solid), then there's no reason to cut out a bunch of metal around the cone. Subwoofers aren't tweeters. Use lots of dynamat and eliminate all the rattles you can.


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## jbowers (May 3, 2009)

HardCoreDore said:


> I was thinking about aperiodic membranes. I remember they became really popular in the late 90's competition scene. I've never had a chance to study the design, although I have heard it's a ***** to get right.
> 
> So infinity baffle is basically "free air" I guess. Unless there's a difference their too.


A lot of people treat the terms "free air" and "infinite baffle" the same, and I think in the 80s and 90s they were used pretty much interchangeably. When most people say "free air" these days, they're referring to running the speaker with no baffle whatsoever, like this:

X-15 Prototype Free-Air Test on SAZ-3500D - YouTube

Infinite baffle is still an enclosure, it's just that your entire trunk in the case of car audio is the enclosure. The key is making sure the front wave and the back wave of the speaker are sealed off from each other, otherwise they'd cancel each other out.


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## jbowers (May 3, 2009)

Andy Wehmeyer said:


> For infinite baffle, the most important consideration is the amount of power you'll apply and the length of the voice coil (Xmax). You won't have the additional protection from overexcursion that you'd have with a sealed box.
> 
> Compared to the Vas of just about any car audio driver you have to choose from, the trunk is HUGE and isn't going to contribute much to the shape of the rolloff.
> 
> Sealing the trunk is overrated. Completely sealing the trunk is overrated. DO NOT go squirting expanding foam between the body panels, etc. In addition, if you take the trim panel off the top of the rear deck and you see a bunch of holes (usually the metal part of the panel isn't solid), then there's no reason to cut out a bunch of metal around the cone. Subwoofers aren't tweeters. Use lots of dynamat and eliminate all the rattles you can.


That was my general thinking, just sealing with sound deadener and maybe a foam or rubber gasket where the baffle bolts together. My Audi has a factory 8" sub in the rear deck. Let's say I fiberglass an enclosure to the bottom of the deck for a single 15 or a pair of 12s. Providing I'm sealed well enough, should that factory mounting hole vent well enough into the cabin?


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## Hoye0017 (Mar 23, 2010)

This thread made me have to ask a question. Shouldn't IB drivers be identified by there Qts and/or Qms? I never see the drivers Q parameters come up in IB conversations, but it was my understanding that these parameters are critical for IB applications. It's my understanding that Higher Q figures means a higher ability to control the drivers natural resonance and control cone movement to guard against over excursion. Both of which seem like critical concepts in IB applications. 

So am I wrong? Why does it seems like this is never brought up in IB discussion.


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## jbowers (May 3, 2009)

Hoye0017 said:


> This thread made me have to ask a question. Shouldn't IB drivers be identified by there Qts and/or Qms? I never see the drivers Q parameters come up in IB conversations, but it was my understanding that these parameters are critical for IB applications. It's my understanding that Higher Q figures means a higher ability to control the drivers natural resonance and control cone movement to guard against over excursion. Both of which seem like critical concepts in IB applications.
> 
> So am I wrong? Why does it seems like this is never brought up in IB discussion.


In my case, I've already done a lot of research and had more of a question of execution of install than some of the other details behind the concept, and maybe that's why none of the others brought it up. That is a good point for anyone else reading this thread curious about IB applications. 

I'm swerving a little bit because I was in a local shop yesterday and happened across a pair of Focal Access 33a 13" subs for ridiculously cheap. The specs are borderline IB suitable with a QTS of .575. I'm thinking of trying these in the deck and if they don't do what I want them to do I'll build new home theater subs out of them. Couldn't resist them for the price though, they'll find a home.


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## kaigoss69 (Apr 2, 2008)

Hoye0017 said:


> This thread made me have to ask a question. Shouldn't IB drivers be identified by there Qts and/or Qms? I never see the drivers Q parameters come up in IB conversations, but it was my understanding that these parameters are critical for IB applications. It's my understanding that Higher Q figures means a higher ability to control the drivers natural resonance and control cone movement to guard against over excursion. Both of which seem like critical concepts in IB applications.
> 
> So am I wrong? Why does it seems like this is never brought up in IB discussion.


I believe the drivers have changed. Low/Medium Qts subs have huge motors now and lots of xmax, and many of them can be successfully used in IB. They also produce tighter bass notes than high Qts drivers, which a lot of people prefer. I believe too much emphasis is/was placed on Vas as well. The "rule" used to be something like 10x Vas for the trunk space. Today we don't pay too much attention to that, and we can get away with much less. The "old" rules are pretty much out of the window. The new rules involve mainly xmax and Fs, and a history of the driver having been used successfully in IB is much more worth than plotting theoretical response curves in WinISD.

Another important factor is the availability of cheap watts and EQ. Even if a driver has a steepish roll-off, the response can be extended through the use of EQ and amp headroom.


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## BuickGN (May 29, 2009)

Hoye0017 said:


> This thread made me have to ask a question. Shouldn't IB drivers be identified by there Qts and/or Qms? I never see the drivers Q parameters come up in IB conversations, but it was my understanding that these parameters are critical for IB applications. It's my understanding that Higher Q figures means a higher ability to control the drivers natural resonance and control cone movement to guard against over excursion. Both of which seem like critical concepts in IB applications.
> 
> So am I wrong? Why does it seems like this is never brought up in IB discussion.


Q is always brought up, maybe not so much lately, but it's been beaten to death. I just don't think it's as important as people make it out to be. Most people use sealed boxes which changes the Q much more and you never hear Q discussed. With most car IB applications Qts = Qtc or very close. Lower Q means better cone control. IB gives better cone control than sealed. I've heard subs with a .2 Qts and they sounded great IB. Admittedly I don't know the Qtc of that system. 

I do think that Q is important in shaping the response obviously but it's absolutely no more important IB than sealed. My personal preference seems to be mid Q setups but that might be coincidence. I think so many people are so used to higher Q setups with subs in too small of a sealed box that they love IB with the typical mid Q flatter response without the boominess and with a quicker punch and better low end. If also seems that lower prices subs can excel without having to overcome the air spring. 

It's been my experience so far, every sub I've tried which has been about 7 has sounded better (to me) IB than sealed. That's why I tell people to use your favorite sealed sub IB and you're probably going to love it.


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## thehatedguy (May 4, 2007)

Don't overlook the JBL WGTi line and the Dayton RS HF line for IB in the car too.


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## theoldguy (Nov 17, 2009)

Home | "Cult of the Infinitely Baffled" Hear The Bass, Not The Box The definitive online resource for Infinite Baffle subwoofer design Established 1999

you just got schooled


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## jbowers (May 3, 2009)

thehatedguy said:


> Don't overlook the JBL WGTi line and the Dayton RS HF line for IB in the car too.


The Daytons sure do look nice, especially for the price. I had an idea that's probably ridiculously complicated and may do nothing, but I'm game for trying. Looking at my deck, the only significant hole is the factory sub mount, otherwise it's pretty much solid metal. Let's say I mount the baffle firing into the rear seatbacks, and mold a duct from in front of the baffle into the factory sub mount location. Too much work? Or should I just cut out the ski pass?

This is what happens when I'm on vacation with too much time on my hands.


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## jbowers (May 3, 2009)

theoldguy said:


> Home | "Cult of the Infinitely Baffled" Hear The Bass, Not The Box The definitive online resource for Infinite Baffle subwoofer design Established 1999
> 
> you just got schooled


Looks like I know what I'm doing for the rest of the day.


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## thehatedguy (May 4, 2007)

The Dayton has parameters that are pretty similar to the other big guys...and some nice copper in the motor. I have had the HF15 in my car for a long time now. I wanted the JBL WGTi15, but my wallet said "no." Though a smart man once told me to buy once, cry once.

I would have to see a picture of your trunk to comment on the install part of things.


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## jbowers (May 3, 2009)

thehatedguy said:


> The Dayton has parameters that are pretty similar to the other big guys...and some nice copper in the motor. I have had the HF15 in my car for a long time now. I wanted the JBL WGTi15, but my wallet said "no." Though a smart man once told me to buy once, cry once.
> 
> I would have to see a picture of your trunk to comment on the install part of things.


I was looking at the Ultimax, which looks like it's got an advantage over the HF in terms of xmax and power handling but a bit smaller sd. I do like the idea of the sleeved pole piece for distortion reduction. 

Ultimax

Resonant Frequency (Fs)19.5 Hz
DC Resistance (Re)3.4 ohms
Voice Coil Inductance (Le)1.31 mH
Mechanical Q (Qms)2.4
Electromagnetic Q (Qes)0.59
Total Q (Qts)0.47
Compliance Equivalent Volume (Vas)7.92 ft.³
Mechanical Compliance of Suspension (Cms)0.24 mm/N
BL Product (BL)14.1 Tm
Diaphragm Mass Inc. Airload (Mms)279.4g
Maximum Linear Excursion (Xmax)19 mm
Surface Area of Cone (Sd)814.6 cm²

HF

Resonant Frequency (Fs)18 Hz
DC Resistance (Re)3.3 ohms
Voice Coil Inductance (Le)1 mH
Mechanical Q (Qms)3.1
Electromagnetic Q (Qes)0.49
Total Q (Qts)0.42
Compliance Equivalent Volume (Vas)9.95 ft.³
Mechanical Compliance of Suspension (Cms)0.28 mm/N
BL Product (BL)14.67 Tm
Diaphragm Mass Inc. Airload (Mms)282.6g
Maximum Linear Excursion (Xmax)14 mm
Surface Area of Cone (Sd)829.6 cm²

I'll take a few trunk pictures today so you have an idea what I'm working with.


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## cajunner (Apr 13, 2007)

jbowers said:


> I was looking at the Ultimax, which looks like it's got an advantage over the HF in terms of xmax and power handling but a bit smaller sd. I do like the idea of the sleeved pole piece for distortion reduction.
> 
> Ultimax
> 
> ...


those two are almost within manufacturer tolerances for the same speaker, except for cone throw.


like, they made one a little smaller around, so the surround could extend an extra 5mm each way.

depending on tuning, either one of these should be pretty nice in IB.


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## Beckerson1 (Jul 3, 2012)

jbowers said:


> I was looking at the Ultimax, which looks like it's got an advantage over the HF in terms of xmax and power handling but a bit smaller sd. I do like the idea of the sleeved pole piece for distortion reduction.
> 
> Ultimax
> 
> ...



I looked at both of those. Seeing that Xmax in IB is one of the huge factors I chose the Ultimax. Plus it models quite well sealed.

Bought two 15" Ultimax subs last weekend at the Tent sale at PE.


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## jbowers (May 3, 2009)

cajunner said:


> those two are almost within manufacturer tolerances for the same speaker, except for cone throw.
> 
> 
> like, they made one a little smaller around, so the surround could extend an extra 5mm each way.
> ...


Sweet. I think I'll pull the trigger on a pair of the Ultimax this week. Once I get everything else I'll start a build log and we'll see how these do.


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## jbowers (May 3, 2009)

Beckerson1 said:


> I looked at both of those. Seeing that Xmax in IB is one of the huge factors I chose the Ultimax.
> 
> Bought two 15" Ultimax subs last weekend at the Tent sale at PE.


Noice! I saw your post in another thread about the purchase. What car are you putting yours in?


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## theoldguy (Nov 17, 2009)

jbowers said:


> Looks like I know what I'm doing for the rest of the day.


ya google searches can do that to you


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## jbowers (May 3, 2009)

theoldguy said:


> ya google searches can do that to you


I went down that rabbit hole and then some. Ended up re-reading all of the DIYMA threads I had looked at before and I think I've got a much better grasp of things - in the end it's much simpler than I was making it out to be in my head. 

Now I just have to bit the bullet and start working in this heat.


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## Patrick Bateman (Sep 11, 2006)

jbowers said:


> I was hoping to avoid cutting this one up like the Jetta, but that might be an option. Aside from the AE subs, what other high efficiency IB suitable subs should I be looking at?


Efficiency is overrated.
As long as you have sufficient power, *the sub with the most displacement wins.* Doesn't matter if the efficiency is 95dB or 80dB, displacement is what counts.


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## Beckerson1 (Jul 3, 2012)

jbowers said:


> Noice! I saw your post in another thread about the purchase. What car are you putting yours in?


2006 Civic Si Coupe


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## Patrick Bateman (Sep 11, 2006)

jbowers said:


> In my case, I've already done a lot of research and had more of a question of execution of install than some of the other details behind the concept, and maybe that's why none of the others brought it up. That is a good point for anyone else reading this thread curious about IB applications.
> 
> I'm swerving a little bit because I was in a local shop yesterday and happened across a pair of Focal Access 33a 13" subs for ridiculously cheap. The specs are borderline IB suitable with a QTS of .575. I'm thinking of trying these in the deck and if they don't do what I want them to do I'll build new home theater subs out of them. Couldn't resist them for the price though, they'll find a home.


With a bank of resistors you can get whatever QTS you want, as long as it is higher. (Resistors raise the QES.)

If you don't want to waste power in resistors, you can raise the QMS by adding mass to the cone. Even a fishing weight will do the trick, but I personally like using stuff like polyurethane glue because it strengthens the cone while adding mass.

You could add a layer of fiberglass or carbon fiber also, but that gets tricky because sometimes you'll kill the surround in the process. (Found out the hard way.)


Basically if I was doing an IB sub I would go and buy a cheap ass fifteen or eighteen that's undermotored, with a lot of xmax and a sturdy cone. If you have a driver already and you want to run it IB, I'd think about raising the QMS with a caulk gun full of liquid nails.


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## cajunner (Apr 13, 2007)

Patrick Bateman said:


> With a bank of resistors you can get whatever QTS you want, as long as it is higher. (Resistors raise the QES.)
> 
> If you don't want to waste power in resistors, you can raise the QMS by adding mass to the cone. Even a fishing weight will do the trick, but I personally like using stuff like polyurethane glue because it strengthens the cone while adding mass.
> 
> ...


how many "cheap ass fifteen/eighteen" you know of with high Xmax?

if they have the stroke, they've usually been designed for high power and cost accordingly.

and adding mass to the cone using distributed weight such as a layer of glue, causes the cone to have new structural modes that do not work as well as the original cone, the better option is how most speaker companies do it, and add a mass ring inside the dust cap around the coil, that doesn't change the speaker's tonal character, and simply adds mass.


not chiding or anything, but getting a driver with .57 Qts is already "in the zone" for being a successful IB candidate, and likely needs very little eq to bump up it's fat bottom to sound pretty sweet.


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## Patrick Bateman (Sep 11, 2006)

cajunner said:


> how many "cheap ass fifteen/eighteen" you know of with high Xmax?
> 
> if they have the stroke, they've usually been designed for high power and cost accordingly.


Alpine Type S is your Value Leader. - diyAudio

^^ I made some spreadsheets for this.
Alpine Type R 15" and Stereo Integrity 18" come to mind.
Generally fifteens and eighteens give you the most bass for your money. When it comes down to sheer output per dollar, it's hard to beat a 15 or an 18. This is probably why eighteens are the most popular subwoofer size in the prosound market; dual 18s are the subs you see the most.



cajunner said:


> and adding mass to the cone using distributed weight such as a layer of glue, causes the cone to have new structural modes that do not work as well as the original cone, the better option is how most speaker companies do it, and add a mass ring inside the dust cap around the coil, that doesn't change the speaker's tonal character, and simply adds mass.
> 
> 
> not chiding or anything, but getting a driver with .57 Qts is already "in the zone" for being a successful IB candidate, and likely needs very little eq to bump up it's fat bottom to sound pretty sweet.


It really depends. For about $150 you can get an Alpine Type R 15", and there's really no reason to modify it. OTOH, if you *really* want to go cheap, you can find some fifteens and eighteens from MCM and Power Acoustik and Pyle that are under $100. These drivers will often work better with a stiffened cone, because untreated paper cones really don't hold up well to long term abuse.

I had this problem with the MCM 55-2421; it has a great price, decent power handling, and there are very few subs that work better in a small horn. *But damn is that cone flimsy.* Swirled some liquid nails on the cone, and it changed the params. It also sounded better; methinks stiffening the cone improved things. But it's hard to say, because the params also changed, so the improvement in the sound may have been due to the change in Q.

It was a subtle difference, but the additional strength in the cone is particularly important in a horn, which is mostly what I build.


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## cajunner (Apr 13, 2007)

Patrick Bateman said:


> Alpine Type S is your Value Leader. - diyAudio
> 
> ^^ I made some spreadsheets for this.
> Alpine Type R 15" and Stereo Integrity 18" come to mind.
> ...


in a bass horn, it would probably be more successful, since the horn naturally rolls off the highs that would be affected by uneven cone density and "cone cry" or non-linear behavior and modes.

I figure Alpine, even the Type S, to be expensive compared to those MCM/Pyle/Power Acoustik versions, but none of them have real high Xmax, like the Type R and it's equals.

Anyways, I wouldn't suggest lathering up a pair of Focal subs with Liquid nails just to get the Qts a little higher.

just seems like an easy fix with equalization, as you wouldn't need much to correct for .58 Qts, which is already quite high.

I wouldn't be expecting a "dry" hit, just as they are.


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## thehatedguy (May 4, 2007)

There was no Ultimax when i bought my sub.

But to me, they seemed a lot like an IDMax...


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## jbowers (May 3, 2009)

Beckerson1 said:


> 2006 Civic Si Coupe


We'll probably have similar results then. I don't think your trunk is much smaller than mine, at least not enough to matter. This is going to be fun.


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## Patrick Bateman (Sep 11, 2006)

cajunner said:


> in a bass horn, it would probably be more successful, since the horn naturally rolls off the highs that would be affected by uneven cone density and "cone cry" or non-linear behavior and modes.
> 
> I figure Alpine, even the Type S, to be expensive compared to those MCM/Pyle/Power Acoustik versions, but none of them have real high Xmax, like the Type R and it's equals.
> 
> ...


I'm half tempted to do a "before and after" on one of my subs, just to prove it works.

I can't think of any negative effects of adding liquid nails to a sub, except that efficiency will go down. (Note that SPL will *not* go down, because SPL is dictated by xmax, not efficiency.)

As far as "cone cry" goes, liquid nails would likely *improve* that, not worsen it. It's damping.


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## jbowers (May 3, 2009)

Patrick Bateman said:


> Efficiency is overrated.
> As long as you have sufficient power, *the sub with the most displacement wins.* Doesn't matter if the efficiency is 95dB or 80dB, displacement is what counts.


Is the best way to figure that something as easy as sd x xmax?



Patrick Bateman said:


> With a bank of resistors you can get whatever QTS you want, as long as it is higher. (Resistors raise the QES.)
> 
> If you don't want to waste power in resistors, you can raise the QMS by adding mass to the cone. Even a fishing weight will do the trick, but I personally like using stuff like polyurethane glue because it strengthens the cone while adding mass.
> 
> ...


Do you see this as more effective in general than EQ? I have plenty of power on tap, so adding resisters isn't really going to be an issue. You have a link for more information on this?



cajunner said:


> Anyways, I wouldn't suggest lathering up a pair of Focal subs with Liquid nails just to get the Qts a little higher.
> 
> just seems like an easy fix with equalization, as you wouldn't need much to correct for .58 Qts, which is already quite high.
> 
> I wouldn't be expecting a "dry" hit, just as they are.


I've already relegated the Focals to a home theater subwoofer build, I figure it's a better fit with my existing Focal surround setup. I have the feeling I'd end up asploding those in the car with their lower power handling and my tendency to turn up the volume knob. 



thehatedguy said:


> There was no Ultimax when i bought my sub.
> 
> But to me, they seemed a lot like an IDMax...


Heh, I saw someone in another thread say *ULTI*MO, ID*MAX*...*ULTIMAX*. If these perform anything like an IDMax I'll be highly satisfied.


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## jbowers (May 3, 2009)

Patrick Bateman said:


> I'm half tempted to do a "before and after" on one of my subs, just to prove it works.
> 
> I can't think of any negative effects of adding liquid nails to a sub, except that efficiency will go down. (Note that SPL will *not* go down, because SPL is dictated by xmax, not efficiency.)
> 
> As far as "cone cry" goes, liquid nails would likely *improve* that, not worsen it. It's damping.


I wonder about doing something non-permanent for an experiment, say a ring of weatherstripping on the front side of a metal or poly cone that wouldn't be damaged pulling it off.


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## Patrick Bateman (Sep 11, 2006)

jbowers said:


> I wonder about doing something non-permanent for an experiment, say a ring of weatherstripping on the front side of a metal or poly cone that wouldn't be damaged pulling it off.


clay would work! As long as the cone isn't so fragile that the clay will tear it. I use clay weatherstripping from Home Depot


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## jbowers (May 3, 2009)

Patrick Bateman said:


> clay would work! As long as the cone isn't so fragile that the clay will tear it. I use clay weatherstripping from Home Depot


Sounds like I need to invest in a WT3 so I can give this a try.


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## Patrick Bateman (Sep 11, 2006)

jbowers said:


> Sounds like I need to invest in a WT3 so I can give this a try.


WT3 is so good I bought it twice.
(it's tiny, easy to lose. About the size of a thumb drive, and I lose those too!)


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## jbowers (May 3, 2009)

Just looked on PE's site, and apparently it's out of production. Bummer.

*edit* Looks like I'm out of the loop: Dayton Audio DATS Dayton Audio Test System


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## iroller (Dec 11, 2010)

Buick GN, sorry I didn't get back sooner I have Esotar 2


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## Orion525iT (Mar 6, 2011)

Slot loading can lower fs _and_ raise Q, provided the cone can take the abuse. You can "tune" by changing the distance between the cone and the wall of the slot.


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## jbowers (May 3, 2009)

Orion525iT said:


> Slot loading can lower fs _and_ raise Q, provided the cone can take the abuse. You can "tune" by changing the distance between the cone and the wall of the slot.


How close to the cones are we talking here? Let's say I built a second adjustable baffle out of 1"-2" thick plexi, would that be suitable? (I kind of want to be able to display the speaker cones by dropping the seatbacks)


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## Orion525iT (Mar 6, 2011)

jbowers said:


> How close to the cones are we talking here? Let's say I built a second adjustable baffle out of 1"-2" thick plexi, would that be suitable? (I kind of want to be able to display the speaker cones by dropping the seatbacks)


Depends really. The usual suggestion is a slot opening of 1/3 cone area to load the front of the cone. Excursion comes into play. My manifolds are push-pull. So two drivers occupy the same slot. However, my slot opening is ~1/3 the cone area of a _single_ driver. But the subs I am using only have 8.8 mm xmax (one way).

You can load the back of the cone too.


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## BuickGN (May 29, 2009)

It's important to note that Qtc is what ultimately matters, not Qts which I think everyone already knows. I've run a system Q of .42 and it's probably the best sounding I've run and with zero EQ required. I've always preferred mid to lower Q. I don't believe .707 should be the goal, at least not for everyone. 

Being general, going too high is going to give that boomy, slow, sloppy bass where it's hard to go too low even when going IB. I think "too low" needs to be redefined. I loved one system I heard with a .34 Qtc but I can make off plenty I've hated with .9Qtc and I think those high Qtc systems happen a lot more than people think due to space restrictions. 

This is why I keep saying paying attention to Qtc is much less important when IB than when sealed. I think we're beginning a new IB era and people are coming around. 

About Fs, I think it's important obviously but why is more attention paid to it when IB when Fsc will always be lower IB. We play right through Fsc all the time with a sealed enclosure and not as often IB. We shoot for a <30hz Fs IB but don't care that the same sub sealed might have an Fsc of 45hz. 

Last, and purely opinion and I don't know why but I've always liked the sound of small box, large motor subs used IB. Is it the damping? Are they just over built?

All of these reasons are why I'm confident that your favorite sealed sub will sound better IB. 

If xmax is too low, add a subsonic until excursion is acceptable. Worst case scenario is you only have the low end extension you had when sealed but you'll retain the awesome efficiency and better damping of IB.


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## Orion525iT (Mar 6, 2011)

BuickGN said:


> It's important to note that Qtc is what ultimately matters, not Qts which I think everyone already knows. I've run a system Q of .42 and it's probably the best sounding I've run and with zero EQ required. I've always preferred mid to lower Q. I don't believe .707 should be the goal, at least not for everyone.
> 
> Being general, going too high is going to give that boomy, slow, sloppy bass where it's hard to go too low even when going IB. I think "too low" needs to be redefined. I loved one system I heard with a .34 Qtc but I can make off plenty I've hated with .9Qtc and I think those high Qtc systems happen a lot more than people think due to space restrictions.


One thing we have left out is cabin gain. A low Qts sub may not look like it has much bottom when IB, because of the roll off. But I think the roll off is actually helpful once cabin gain comes into play. 

FYI, the subs I am using have a Qts of .330. Big high BL motor with tiny cone and not much xmax. But I got multiples .


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## BuickGN (May 29, 2009)

So far I'm loving the ID Max15 IB. I was worried with the 300g Mms at first. I know motor strength will make up for it but I was worried about losing detail. In the <120hz range I feel that I have lost nothing over the IB15s. Well, that I can tell with a week worth of listening. The point being these large heavy semi small box (relatively speaking) subs that were never designed for IB do very well IB. So did my 12W6s, 13W7s, and several others. The one I HATED was my Tempest X. It had nothing past 50hz and was sloppy sounding. Maybe if used for 10-35hz HT material it would be better. 

On the flip side, I believe Erin liked his HT version high Qts IB15s better than his AU .46 Qts version in the same car. Go figure.


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## jbowers (May 3, 2009)

BuickGN said:


> It's important to note that Qtc is what ultimately matters, not Qts which I think everyone already knows. I've run a system Q of .42 and it's probably the best sounding I've run and with zero EQ required. I've always preferred mid to lower Q. I don't believe .707 should be the goal, at least not for everyone.
> 
> Being general, going too high is going to give that boomy, slow, sloppy bass where it's hard to go too low even when going IB. I think "too low" needs to be redefined. I loved one system I heard with a .34 Qtc but I can make off plenty I've hated with .9Qtc and I think those high Qtc systems happen a lot more than people think due to space restrictions.
> 
> ...


I've always gravitated towards the overdamped small box setups generally, but you're right about being too boomy/peaky and needing way too much EQ - not to mention the waste of power. 

I'd love to try my favorite sub IB, but according to Nick Lemons the SI Mag V4s will destroy themselves in anything but a 1.1 cu ft or smaller enclosure. :laugh:
Seems like the thing to do is try a pair of the Ultimax then EQ to taste.


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## BuickGN (May 29, 2009)

Orion525iT said:


> One thing we have left out is cabin gain. A low Qts sub may not look like it has much bottom when IB, because of the roll off. But I think the roll off is actually helpful once cabin gain comes into play.
> 
> FYI, the subs I am using have a Qts of .330. Big high BL motor with tiny cone and not much xmax. But I got multiples .


Forgive me for not looking but by internet is painfully slow at my hotel, what kind of subs do you have and are they running IB? I'm always interested in those out of the norm.


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## BuickGN (May 29, 2009)

jbowers said:


> I've always gravitated towards the overdamped small box setups generally, but you're right about being too boomy/peaky and needing way too much EQ - not to mention the waste of power.
> 
> I'd love to try my favorite sub IB, but according to Nick Lemons the SI Mag V4s will destroy themselves in anything but a 1.1 cu ft or smaller enclosure. :laugh:
> Seems like the thing to do is try a pair of the Ultimax then EQ to taste.


I bet they would work fine. He's probably worried about warranty claims. Just watch excursion and as long as it doesn't get out of control you're fine. 

I would like to hear a review of the ultimax sub. 

Also, a smaller enclosure hurts damping so a very small enclosure would be under damped. That why you get the opposite of tight bass, it becomes boomy.


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## jbowers (May 3, 2009)

BuickGN said:


> I bet they would work fine. He's probably worried about warranty claims. Just watch excursion and as long as it doesn't get out of control you're fine.
> 
> I would like to hear a review of the ultimax sub.
> 
> *Also, a smaller enclosure hurts damping so a very small enclosure would be under damped*. That why you get the opposite of tight bass, it becomes boomy.


This is what happens when I drink and internet. 

I'm hoping to get started next week, so I might just have a review soon.


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## BuickGN (May 29, 2009)

jbowers said:


> This is what happens when I drink and internet.
> 
> I'm hoping to get started next week, so I might just have a review soon.


Lol. The only reason I bring it up is because for a long time everyone thought IB had less cone control. 

I hear you about drinking and internet. I haven't drank since my company Christmas party last year and now that I'm on vacation I stay far from the internet. You think I sound ignorant now, you wouldn't believe what just one beer will do lol. Chances or slim I will be back before this time tomorrow.


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## jbowers (May 3, 2009)

BuickGN said:


> Lol. The only reason I bring it up is because for a long time everyone thought IB had less cone control.
> 
> I hear you about drinking and internet. I haven't drank since my company Christmas party last year and now that I'm on vacation I stay far from the internet. You think I sound ignorant now, you wouldn't believe what just one beer will do lol. Chances or slim I will be back before this time tomorrow.


I'm on vacation too, took a few weeks off while changing jobs. Celebrated by upgrading cars and now I'm going to do all the things I wanted to do on the old one, but better. Also, booze.


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## thehatedguy (May 4, 2007)

If you want to experiment with adding mass, get some washers and tape them to the cone. No need to completely ruin something with Liquid Nails. That way you will have a standard mass to work with if you find a sweet spot.


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## jbowers (May 3, 2009)

thehatedguy said:


> If you want to experiment with adding mass, get some washers and tape them to the cone. No need to completely ruin something with Liquid Nails. That way you will have a standard mass to work with if you find a sweet spot.


Something like this would work. I'm tempted to try this on an old Rockford T1 I have laying around, since I don't care what happens to it.


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## thehatedguy (May 4, 2007)

It would be quicker than waiting for the LN to dry...and more importantly, easily repeatable.

And if you didn't want to mess the front of the cone up, you could do everything on the backside of the cone pretty easy.

Then depending on how much you wanted to experiment and tweak, you could get a gross idea on the mass you need with one size washer, and then zero in on a more exact mass with smaller washers.

That and you could distribute the mass evenly around the cone.


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## jbowers (May 3, 2009)

thehatedguy said:


> It would be quicker than waiting for the LN to dry...and more importantly, easily repeatable.
> 
> And if you didn't want to mess the front of the cone up, you could do everything on the backside of the cone pretty easy.
> 
> ...


This is definitely an experiment that needs to be had. When the DATS is back in stock at PE I'll dive into it. I've got drivers with different types of cone material laying around, so I'd be able to see if any of those benefit more or less with adding mass.


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## Patrick Bateman (Sep 11, 2006)

BuickGN said:


> I bet they would work fine. He's probably worried about warranty claims. Just watch excursion and as long as it doesn't get out of control you're fine.
> 
> I would like to hear a review of the ultimax sub.
> 
> Also, a smaller enclosure hurts damping so a very small enclosure would be under damped. That why you get the opposite of tight bass, it becomes boomy.


^^ agree

All of the variations on dipole are insanely hard on a driver, they're basically a manufacturers worst nightmare as far as returns go.

You need a LOT of displacement to make it work. If you like the sound of a sealed 8", you might need as much as 10x the displacement to get a similar level of output with a dipole or cardioid.

It's *really* tough to get enough output, but if you got the power and you got the displacement it can really sound magical.

Probably the best 'bang for the buck' subwoofer that I've ever had was a dipole using a pair of TC Sounds fifteens. Powered it with a 350watt plate amp and that thing could shake the room with no box whatsoever.


Nowadays I definitely prefer cardioid; basically gives you the best of both worlds. (You can make a cardioid using a sealed box *and* a dipole together.)

It's cool to see that Linkwitz is coming around too; his new speaker is cardioid.


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## Patrick Bateman (Sep 11, 2006)

jbowers said:


> This is definitely an experiment that needs to be had. When the DATS is back in stock at PE I'll dive into it. I've got drivers with different types of cone material laying around, so I'd be able to see if any of those benefit more or less with adding mass.


woofertester.com

Not sure if it's the exact same thing, but it sure *looks* similar


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## req (Aug 4, 2007)

Patrick Bateman said:


> I can't think of* any negative effects *of adding liquid nails to a sub, except that efficiency will go down.




ill give you one negative effect - you will ruin the speaker and make it look horrible. lol. unless the cone will never be visible and it is a speaker that is very inexpensive, i would not advise doing this to anyone


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## 14642 (May 19, 2008)

Patrick Bateman said:


> With a bank of resistors you can get whatever QTS you want, as long as it is higher. (Resistors raise the QES.)
> 
> If you don't want to waste power in resistors, you can raise the QMS by adding mass to the cone. Even a fishing weight will do the trick, but I personally like using stuff like polyurethane glue because it strengthens the cone while adding mass.
> 
> ...


Of you could just put anything back there that has enough Xmax for the amount of power you want to use and EQ the response.


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## sqnut (Dec 24, 2009)

thehatedguy said:


> Then depending on how much you wanted to experiment and tweak, you could get a gross idea on the mass you need with one size washer, and then zero in on a more exact mass with smaller washers.
> 
> That and you could distribute the mass evenly around the cone.


That right there is a tweaker's worst nightmare. The back and forth with ever smaller washers would eventually drive you over the edge.


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## jbowers (May 3, 2009)

Patrick Bateman said:


> woofertester.com
> 
> Not sure if it's the exact same thing, but it sure *looks* similar


I'd be willing to bet it's where the PE woofer testers started with a license, then evolved from there.


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## Patrick Bateman (Sep 11, 2006)

req said:


> ill give you one negative effect - you will ruin the speaker and make it look horrible. lol. unless the cone will never be visible and it is a speaker that is very inexpensive, i would not advise doing this to anyone


I suck at cosmetics

I electrocuted a girl with my stereo, good thing it was only 12v, or else I'd be single now


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## jbowers (May 3, 2009)

Andy Wehmeyer said:


> Of you could just put anything back there that has enough Xmax for the amount of power you want to use and EQ the response.


That's what I'm hoping the Ultimaxs will do. I'm sure whenever Audiofrog's subs are ready I'll be destroying my wallet to get those installed. 

Side note, Andy. When I was in a local shop over the weekend the guy behind the counter was shocked that I knew what I was talking about, so he asked me if I'd heard of Audiofrog. He's never been on DIYMA and was under the impression you've got product ready to go. Word is spreading, I think you're going to be surprised how much buzz there is.


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## jbowers (May 3, 2009)

sqnut said:


> That right there is a tweaker's worst nightmare. The back and forth with ever smaller washers would eventually drive you over the edge.


This is DIYMA. For some people that's the entire point.


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## jbowers (May 3, 2009)

Patrick Bateman said:


> I suck at cosmetics
> 
> I electrocuted a girl with my stereo, good thing it was only 12v, or else I'd be single now


Some guys go their entire lives without giving a girl the tingle.


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## Patrick Bateman (Sep 11, 2006)

Andy Wehmeyer said:


> Of you could just put anything back there that has enough Xmax for the amount of power you want to use and EQ the response.


things I'm bad at:

1) cosmetics
2) K.I.S.S.

this is me: snopes.com: NASA Space Pen

But, in all seriousness, my Mom did work on the space program, and these type of stories happened all the time.


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## Patrick Bateman (Sep 11, 2006)

jbowers said:


> Some guys go their entire lives without giving a girl the tingle.


Girls love a guy in a Ford Escort with no door panels and two holes in the floor that he cut to do infinite baffle midbasses. I was a real lady killer. Random zaps from my crappy wiring was just icing on the cake.

And then there was the time the entire electrical system caught on fire while going down the freeway...


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## sqnut (Dec 24, 2009)

jbowers said:


> This is DIYMA. For some people that's the entire point.


Really? My bad. I thought this was the horse breeders forum .


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## jbowers (May 3, 2009)

Patrick Bateman said:


> Girls love a guy in a Ford Escort with no door panels and two holes in the floor that he cut to do infinite baffle midbasses. I was a real lady killer. Random zaps from my crappy wiring was just icing on the cake.
> 
> And then there was the time the entire electrical system caught on fire while going down the freeway...


Watched a customer's car burn to the ground in the shop parking lot once. There was such a rat's nest of electrical tape and wire nuts under the dash the installer refused to touch the car, and to prove his point it caught on fire while we were arguing with the customer. 



sqnut said:


> Really? My bad. I thought this was the horse breeders forum .


Oh, you must have been in the Amish sub-forum


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## Patrick Bateman (Sep 11, 2006)

jbowers said:


> Watched a customer's car burn to the ground in the shop parking lot once. There was such a rat's nest of electrical tape and wire nuts under the dash the installer refused to touch the car, and to prove his point it caught on fire while we were arguing with the customer.












For the life of me I can't figure out why anyone would get into a Lamborghini or a Ferrari these days. When my electrical system caught on fire it was scary, but the car was still capable of making it home. A small electrical fire in a carbon fiber car could be fatal, due to all of the composites in the car.


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## jbowers (May 3, 2009)

Patrick Bateman said:


> For the life of me I can't figure out why anyone would get into a Lamborghini or a Ferrari these days. When my electrical system caught on fire it was scary, but the car was still capable of making it home. A small electrical fire in a carbon fiber car could be fatal, due to all of the composites in the car.


I'm guessing the people who can afford these cars live a lifestyle that makes them believe nothing bad can ever happen to them. I'm surprised that with all the German cars I've owned I've never had a total loss. Jenky old 911, 280E, SL600, ML430, GTI, Jetta and now the A4...knock on wood. Pretty much all of them were notorious for electrical issues, as in if it has a plug it will fail.


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## 99dx (Jun 7, 2007)

Does it matter what side of the "wall" the woofer faces? I'm thinking of mounting a sub in the rear deck and have the sub firing into the trunk allowing for less magnet hanging down into the trunk and tucked up into the factory hole.


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## Patrick Bateman (Sep 11, 2006)

99dx said:


> Does it matter what side of the "wall" the woofer faces? I'm thinking of mounting a sub in the rear deck and have the sub firing into the trunk allowing for less magnet hanging down into the trunk and tucked up into the factory hole.


Acoustically, it doesn't matter, as long as you flip the polarity when you flip the woofer, but I would think that flipping it would be a thief magnet and would also look odd. What's the motivation to do it?


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## 99dx (Jun 7, 2007)

Patrick Bateman said:


> Acoustically, it doesn't matter, as long as you flip the polarity when you flip the woofer, but I would think that flipping it would be a thief magnet and would also look odd. What's the motivation to do it?


Just trying to save space. It's a new honda accord and I love the trunk and how large it is. There is a stock sub in it already but it is lacking to say the least. I have a dayton reference hanging around and thought I could install it upside down with the magnet tight up to the grill and wouldn't have to worry about excursion. I would have to build a small box structure to fit up against the back deck lid, but I'm thinking it would be less intrusive than the magnet.


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## Patrick Bateman (Sep 11, 2006)

99dx said:


> Just trying to save space. It's a new honda accord and I love the trunk and how large it is. There is a stock sub in it already but it is lacking to say the least. I have a dayton reference hanging around and thought I could install it upside down with the magnet tight up to the grill and wouldn't have to worry about excursion.


If you go IB you'll want lots and lots of displacement.
I'm talking about a couple of twelves *at least*.

When you put a driver in a very large box you're trading output at low frequency for output higher up. IE, less output at 60hz and more output at 30hz.

Due to that, a small sub in an IB is going to sound anemic.


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## 99dx (Jun 7, 2007)

Thats what I thought from reading through the thread. I'm not comfortable slicing up a new car or building something to extreme. I thought I might be able to improve on the stock sub with something a bit more beefy. Anemic is a good word to describe what came stock.


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## Patrick Bateman (Sep 11, 2006)

99dx said:


> Thats what I thought from reading through the thread. I'm not comfortable slicing up a new car or building something to extreme. I thought I might be able to improve on the stock sub with something a bit more beefy. Anemic is a good word to describe what came stock.


Yep, same problem with my Genesis.

I think it basically breaks down like this:

If you can do IB, and you have a pass-through and space for a couple of twelves, that's a good option.

If you want to do IB, but you don't have the space for a couple of twelves, I'd think long and hard about a sealed box, a bandpass, or a vented box. An IB with a single eight or a single ten won't have much 'weight.'


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## gijoe (Mar 25, 2008)

I had 2 IDQ 10's IB for a long time and they did ok. I went to 3 IDQ 10's and it was better. Now I'm running 2 AE SBP 15's and it's much better. The SPL they produce is plenty with the cones barely moving. My point is, 2 10's is doable for a nice, mild, bass. But they will run out of excursion pretty fast IB. I personally wouldn't do IB with anything less than 2 10's.


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## Patrick Bateman (Sep 11, 2006)

gijoe said:


> I had 2 IDQ 10's IB for a long time and they did ok. I went to 3 IDQ 10's and it was better. Now I'm running 2 AE SBP 15's and it's much better. The SPL they produce is plenty with the cones barely moving. My point is, 2 10's is doable for a nice, mild, bass. But they will run out of excursion pretty fast IB. I personally wouldn't do IB with anything less than 2 10's.


That's been my experience too.

It's one of the reasons that manifold setups like the Tymphany LAT are so interesting; basically maximize displacement versus foot print.


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## yogegoy (Feb 11, 2011)

Patrick Bateman said:


> A small electrical fire in a carbon fiber car could be fatal, due to all of the composites in the car.


This is the Porsche Carrera that *Paul Walker* died in. Now I feel depressed, you should have used a correct image of a vehicle electrical fire. RIP Paul Walker


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## Patrick Bateman (Sep 11, 2006)

yogegoy said:


> This is the Porsche Carrera that *Paul Walker* died in. Now I feel depressed, you should have used a correct image of a vehicle electrical fire. RIP Paul Walker


Driver was my coworker


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## BuickGN (May 29, 2009)

If you're running out of excursion IB, a HP filter is a good option. Apply the filter to roughly match a sealed box's response and you will be able to crank the volume just as you would sealed. You lose some low end but no worse than you would with the same subs sealed and you retain the advantages of IB. 

There's a no reason a single 10" shouldn't do just as well IB as sealed.


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## yogegoy (Feb 11, 2011)

Patrick Bateman said:


> Driver was my coworker


Is the shop still operational? *RIP Paul Walker and Roger Rodas*.:angel:


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