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post #31 of 52 Old 02-22-2013, 11:48 AM
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Originally Posted by j1gold16 View Post

I would consider this a hybrid version of a horn suited for car audio use. Given the size limitations of vehicles, a traditional horn design would not be suitable.

Well getting ready to build one of Bill's AutoTubas using dual 8" and from reviews they are pretty kick ass.
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post #32 of 52 Old 02-22-2013, 12:51 PM - Thread Starter
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Oh?

Do small woofers in horns sound better than larger woofers in bass reflex designs that have a horn-like port using the same size box?
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post #33 of 52 Old 02-22-2013, 01:16 PM
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Originally Posted by j1gold16 View Post

Do small woofers in horns sound better than larger woofers in bass reflex designs that have a horn-like port using the same size box?
A horn requires a certain length and mouth area to function. Simply put, if the driver is too big there's not enough room left in the box for the horn. And where horns are concerned the adage 'if you're not going to do it right don't do it at all' holds true.

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post #34 of 52 Old 02-22-2013, 08:28 PM - Thread Starter
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If I just went with a 4.0 ft^3 sealed enclosure, would I still get that deep base rumble for movies? The JL Audio home subwoofers are sealed and seem to produce pretty good SPL numbers in the lower frequencies.
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post #35 of 52 Old 02-22-2013, 09:42 PM
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"If I just went with a 4.0 ft^3 sealed enclosure, would I still get that deep base rumble for movies?"

yeah, you would do ok to put each w15gti in a 4 cubic foot enclosure sealed.

an inuke 3000dsp will work for both amp and equalization. each channel will produce about 750 watts, which pushes the driver to about its limit in those enclosures.

yours would be an easy build and very capable system. be sure to build the cabinets solid with good bracing and make them air tight.

if you want to purchase flat packs, check out diysoundgroup.com. i think erich is having some 15" cutout baffles made for the 4.0 cubic foot enclosures. they cost a little over a hundred buck delivered and are a cinch to assemble.
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post #36 of 52 Old 02-23-2013, 02:15 AM
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Originally Posted by gtpsuper24 View Post

Well getting ready to build one of Bill's AutoTubas using dual 8" and from reviews they are pretty kick ass.

A good single 12 ported would probably have just as much output take up less room and be easier to build.
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post #37 of 52 Old 02-23-2013, 09:10 AM - Thread Starter
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A good single 12 ported would probably have just as much output take up less room and be easier to build.

That's what I thought. Although, that horn has a coolness factor that can't be matched by a single 12 in a ported enclosure.
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post #38 of 52 Old 02-23-2013, 09:23 AM
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Plans are simple and easy to read. Now if you was comparing a ported box vs a horn enclosure you were trying to design yourself, it probably would be much easier to do the 12" ported. I would say a dual 8" AT would probably out perform a decent 12" ported sub and use less power and sound cleaner doing it.

$60-150 for a pair of compatible woofers, $15 for the plans and then just the price of the MDF and other accessories and you got a great performing system. 12" ported on the other hand could cost you more just for the driver than the entire AT.

I've read from many people that horn/tuba enclosures have the sound quality of a good sealed system but has some of the benefits of a ported as well. Low group delay, low distortion (woofers barely move) and efficient.

http://www.billfitzmaurice.com/autotuba.html
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post #39 of 52 Old 02-23-2013, 10:59 AM - Thread Starter
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I played around with WinISD this morning and came up with two possible designs. I threw horns and transmission lines out as possibilities as I have no experience with those. Each woofer will have its own enclosure so I can place them in different spot in the room. The sealed enclosure I came up with is 4.2 ft^3. The ported enclosure nets to 7.5 ft^3. I would us a 4" Precision Port from parts express. Not sure on the length of those. The middle section is 12" in length but I read somewhere that with the ends it's 17" in length. Regardless, it give me a tuning frequency below 20 Hz. The only issue I see is, with 1,000 watts, port velocity would be 53 m/s. I've read that this should be below 20 m/s. I could use a slot port but I'm not sure if I would flare the ends as I want to add wood veneer to the box and stain it. I'm leaning toward the ported design as it is 10 decibels louder at 15 hz. That would be awesome for movies. How do you think it would sound with music? Help!!!
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post #40 of 52 Old 02-23-2013, 11:48 AM
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Quote:
Originally Posted by gtpsuper24 View Post

Plans are simple and easy to read. Now if you was comparing a ported box vs a horn enclosure you were trying to design yourself, it probably would be much easier to do the 12" ported. I would say a dual 8" AT would probably out perform a decent 12" ported sub and use less power and sound cleaner doing it.

$60-150 for a pair of compatible woofers, $15 for the plans and then just the price of the MDF and other accessories and you got a great performing system. 12" ported on the other hand could cost you more just for the driver than the entire AT.

I've read from many people that horn/tuba enclosures have the sound quality of a good sealed system but has some of the benefits of a ported as well. Low group delay, low distortion (woofers barely move) and efficient.

http://www.billfitzmaurice.com/autotuba.html

I have seen the Alpine Type R sell for as low as $99 new, I just picked up 4 15's $300 plus shipping. That's 75 a piece. Know one has any idea what type of real world SPL a Auto tuba produces. The Alpine will over a 130DB's depending on the car and install.
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post #41 of 52 Old 02-23-2013, 02:14 PM
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"How do you think it would sound with music? Help!!!"

it will sound good. two 4" ports would be closer to what most folks would use in order to keep air velocity lower (as you pointed out).

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post #42 of 52 Old 02-25-2013, 10:50 AM
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I have used PWK for car audio enclosures for the last 5-6 years. They perform and measure as he predicts as long as the information given to him is correct. I started using him because I wanted to try a ported enclosure and had not ever built one. The blueprints provided were very easy to use for assembly. Now he does provide plans for home audio mains as well as subs but has said at least once that he does not have much experience trying below 20 hertz.

He does claim to give you the best performance for what you are asking for based on woofer used and vehicle cabin gain and that the enclosure is very vehicle woofer specific. I disagree as I have tried several of the designs with different woofers and vehicles and had excellent results. I have tried a couple of other "designers in the car audio world and none so far have given what Pete offers. What I have ended up with is usually a ported enclosure tuned to 30-35 hertz with zero attention to excursion for whatever power level I am using. So I give Pete Kudo's for that!

He does say his software is his own design and is not using an off the shelf freeware or purchased product.

I do recommend him to kids (I have a 20 year old as well as 16 year old nephew), mine and their friends, because it is just easier and the performance is always better than a prefab or what I have seen come out of local shops. Of course the same can be said as I have purchased the THT and had excellent results from that and thereby feel comfortable recommending that as well as this website forum for home theater projects.

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post #43 of 52 Old 02-25-2013, 05:26 PM
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Quote:
Originally Posted by j1gold16 View Post

I played around with WinISD this morning and came up with two possible designs. I threw horns and transmission lines out as possibilities as I have no experience with those. Each woofer will have its own enclosure so I can place them in different spot in the room. The sealed enclosure I came up with is 4.2 ft^3. The ported enclosure nets to 7.5 ft^3. I would us a 4" Precision Port from parts express. Not sure on the length of those. The middle section is 12" in length but I read somewhere that with the ends it's 17" in length. Regardless, it give me a tuning frequency below 20 Hz. The only issue I see is, with 1,000 watts, port velocity would be 53 m/s. I've read that this should be below 20 m/s. I could use a slot port but I'm not sure if I would flare the ends as I want to add wood veneer to the box and stain it. I'm leaning toward the ported design as it is 10 decibels louder at 15 hz. That would be awesome for movies. How do you think it would sound with music? Help!!!

Hey J1!! cool subs, I agree with you about the coolness factor for a 15... Now, I went a little too fast through your post but you didn't list any room dimensions right? Other people are right in mentioning the listening space and the various room peaks you may encounter depending on your seating location... If you have that room size let us know, maybe 1 sub will do! I would go ported with a slot port (just more port area to play with..)

Cubdenno is right about PWK, nothing wrong in having someone factor in all your variables in his own software to have a more precise model. Now, I'm more of a DIY guy and have always made my enclosures, started when I was 12 and probably have made way more ported than sealed... Sealed is just not my way of thinking, you are just wasting the back side of the cone!! not efficient... Better sounding? Not all the time. Less space? depends on the sub..

What kind of music do you listen to? a 15Hz response is just asking for room rattles instead of music reproduction (not that that is cool or not)... If you listen to Pipe organ music then maybe go down to 20... I know I love it when the lady at church hit's the low notes on the pipes even on church music smile.gif ... The wife can't hear it, everybody else seems like, "What? that's just the organ right?" (think that the pipes are there for decoration...)
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post #44 of 52 Old 02-25-2013, 05:58 PM
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What kind of music do you listen to? a 15Hz response is just asking for room rattles instead of music reproduction (not that that is cool or not)... If you listen to Pipe organ music then maybe go down to 20...
This is predominantly a HT forum, and if you do a little research, then there is often considerable SFX energy down into single digits. Some people here have systems that can go very, very loud and deep. If I was doing a music only system I wouldn't bother much <30Hz.
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post #45 of 52 Old 02-28-2013, 05:58 PM - Thread Starter
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Hey J1!! cool subs, I agree with you about the coolness factor for a 15... Now, I went a little too fast through your post but you didn't list any room dimensions right? Other people are right in mentioning the listening space and the various room peaks you may encounter depending on your seating location... If you have that room size let us know, maybe 1 sub will do! I would go ported with a slot port (just more port area to play with..)

Room dimensions are approximately 20' x 35' x 10'. There is a vaulted ceiling that is approximately 14' at the peak. The living room, kitchen, and dining area are all in one. Also, I don't think I mentioned the amp I will be using. I've decided to use the Crown XLS 2500 in conjunction with a MiniDSP. I'm still back and forth on whether to go sealed or ported. I am concerned about the lows not being loud enough for home theater use but I tend to forget that these will have 3 times the cone area and 5 times the power of my current setup. I can always turn up the amp and reduce the higher sub frequencies via EQ if I choose to go sealed so I get a flat room response. I am enlisting the help of my uncle who is a cabinet maker and I don't want to waste a lot of his time having him help me build sealed and ported enclosures. My recent bad experience with sealed enclosures makes me hesitant, yet some of the best subs on the market utilize a sealed design. There is a desire to experience that sub 20 Hz rumble when watching movies. Can this be obtained with a sealed design with the woofer and amp selection I laid out or is ported my only option? There is also a mediocre desire to keep the subwoofer down in size (I have to keep the girl happy; sorry guys).
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post #46 of 52 Old 09-12-2013, 03:08 PM
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Don't know if you decided to use Pete or not. I will say that I have used his services for car audio a couple of times and he had been spot on. I have the abilities to model and design for myself. what he came up with did exceed my own. He has the ability to model areas that most of us simply can't. I have seen him use front and rear loaded horns, bp (4th, 6th, and even 8th), simple ported or even sealed. Whatever best suits the customers requirements and space.

Now I will say that I have not or would use him for my crossover designs but for sub enclosures he his hard to beat.
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post #47 of 52 Old 09-13-2013, 01:31 PM
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Just an FYI, I ordered a box design for my car from PWK - built per spec and it did not sound even close to what I have designed myself. I was extremely disappointed, not only did I buy the design, but I wasted a lot of my time building it.
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post #48 of 52 Old 09-13-2013, 08:51 PM
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Just an FYI, I ordered a box design for my car from PWK - built per spec and it did not sound even close to what I have designed myself. I was extremely disappointed, not only did I buy the design, but I wasted a lot of my time building it.

Would love more specifics. Such as seeing the design, what subwoofers used, what vehicle and what you asked for. Don't need to see the entire design, just the 3d version, and basic hxwxd dimensions.

Also what is lacking?

Sub bass in a car is so easy that I often find it hard to have cruddy low end in a car. I have usually found something wrong elsewhere. Even a bad design unless it is a one note wonder usually sounds good.

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post #49 of 52 Old 09-14-2013, 01:40 PM
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Sub bass in a car is so easy that I often find it hard to have cruddy low end in a car. I have usually found something wrong elsewhere. Even a bad design unless it is a one note wonder usually sounds good.

Sealed sub and eq is the best IMO. Not sure why many seek out odd ball designs. I had planned on going with the Autotuba but the Exodus Shiva X2's in 2cuft sealed enclosures with 800watts each is pure awesome, great midbass and deep tactile bass. Simple and easy.
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post #50 of 52 Old 09-16-2013, 08:15 AM
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Sealed sub and eq is the best IMO. Not sure why many seek out odd ball designs. I had planned on going with the Autotuba but the Exodus Shiva X2's in 2cuft sealed enclosures with 800watts each is pure awesome, great midbass and deep tactile bass. Simple and easy.

Yeah sealed is truly the easiest and most forgiving with the exception of a simple baffle board mount (Car IB).

Going with a more exotic enclosure can yield some serious performance gains in output. That's why you use them. For most car audio people (I am saying the 16-25 year olds, its about output. Pure and simple. How loud am I and am I louder than my buddies?

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post #51 of 52 Old 09-16-2013, 08:37 AM
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Quote:
Originally Posted by gtpsuper24 View Post

Sealed sub and eq is the best IMO. Not sure why many seek out odd ball designs. I had planned on going with the Autotuba but the Exodus Shiva X2's in 2cuft sealed enclosures with 800watts each is pure awesome, great midbass and deep tactile bass. Simple and easy.
And expensive. Like all of my designs, the AT capitalizes on the sweat equity of the builder. It only needs a $35 driver and a 50 watt amp to give excellent results. Not that there's anything wrong with using large, expensive drivers with big amps, that's just as valid a method of getting what you want. But it's not the only method.

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post #52 of 52 Old 09-16-2013, 07:03 PM
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I built the single 8" McM auto tuba for my son, and he's very proud of the tiny amp he can use compared to his friends who mostly have 12s in their cars. It was very easy to build and would take about the same space as two sealed 10s or 12s. It's the one shown on Bill's product page actually (pats self on back)
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