False Info?

I went to my local dealer JL dealer and asked the guy working there how much a sealed box for 2 12W6v2s would be.  He said first of all I recommend you use a ported box because it is more efficient, louder, has better sound quality, and has more bass extention.  I understand that a ported box requires less power and has more SPL, but doesn't a sealed box have better SQ?  And I thought that ported boxes didn't extend the frequency of a sub.  Am I right or was that guy really telling the truth?

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That's my opinion. Take it, leave it, or correct me.

Actually thats wrong, a ported box can be made to sound better than a sealed box, it all depends on the woofer and box design.  Once you figure out how to build ported box's proper with the correct specs, you will never want to go back to sealed.

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2003 Chevy Avalanche,Eclipse CD7000,Morel Elate 5,Adire Extremis,Alpine PDX-4.150, 15" TC-3000, 2 Alpine PDX-1.1000, 470Amp HO Alt.

But then why in SQ comps do they use sealed boxes?

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That's my opinion. Take it, leave it, or correct me.

Because vented enclosures are HUGE, compared to a sealed enclosure for an equivalent low frequency cut-off. Really, this is about it, next to the previously mentioned difficulty in building one correctly.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

These new slot ported boxes are hard to beat for spl if u set them up right making sure u use a sub bass filter and all, but as for sound quality i believe you will never beat a  well built sealed box.  I personally have never felt a ported box hit  a lower note than a sealed box .(try hitting 10 to 12hz in a ported box) if u have let me know i would love to see box plans so i can experiment.

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rottenbellys 05 crew cab colorado.Pioneer dehp 880prs, kenwood excelon in all 4 doors. Bazooka 500 mono Jl 10w3 in coustom center console box.

personally i think a well made ported box built and designed well and cutom 4 these subs are the best way to go--sometimes this means a huge box though

rottenbelly wrote:

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I personally have never felt a ported box hit  a lower note than a sealed box .(try hitting 10 to 12hz in a ported box) if u have let me know i would love to see box plans so i can experiment.

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if you have heard a box hit 10-12hz id like to know how? our ears are only capable of 20hz - 20khz

You can't hear that low, and he is talking about SQ not SPL, they arn't the same thing.

Sorry for not being technical ! if u have felt one go that low let me know.

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rottenbellys 05 crew cab colorado.Pioneer dehp 880prs, kenwood excelon in all 4 doors. Bazooka 500 mono Jl 10w3 in coustom center console box.

Couple of interesting observations. If I read correctly JL's 1961 Mini was built with 2  12" W6V2 woofers that have inserts that remove to convert them to either sealed or vented. With all that was said above and the room for vented box why would they offer the sealed set up? Why did the JL retailer say what he did if JL offers sealed and vented box designs on their websight. And Arrow, did he know what amount of space your box could take up? Just curious.

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There is no such thing as free installation!

i kind of didn't get to mention how much space I had.  He was a little too focused on the ported idea.  I wanted a smaller box and better SQ.

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That's my opinion. Take it, leave it, or correct me.

Then he's an idiot. You ALWAYS focus on the car first. What good is insisting on a vented box when it won't fit? Sometimes I'm embarressed to be in this business with guys like this. JL's 12" W6V2s sound great in a 1.25 cu. ft. sealed box, don't be discuraged.

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There is no such thing as free installation!

they do sound great, it's the w7 that sounds better in a ported box

Ok thanks for the info.  I heard that 12W6v2s sound good in a 1.25 cu. ft. sealed box.  I wasn't sure because I haven't been able to listen to one in that size box.  Thanks guys.

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That's my opinion. Take it, leave it, or correct me.

rottenbelly wrote:

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(try hitting 10 to 12hz in a ported box) if u have let me know i would love to see box plans so i can experiment.

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It's called a tranmission line - effectively a port attached to the back of a woofer. I have TWO of them, with resonant frequencies of (the first one I built) of 12Hz, and (the second one I built) 13.5Hz. They use RADIO SHACK 18 inch woofers, and I can do 12Hz all day long! With 50 watts per channel, I can hit 106dB at 12Hz, and while it can't be HEARD as such, the effect is palpable - and I have actually shaken dishes out of the cupboard. MAN, was my wife PISSED! Do you think that's a worthless frequency response - down to 12Hz? Nope, there IS fundamental information recorded that low in many recordings. Enya's "The Longships" is a perfect example. 36 inch kettle drums, I believe. Alphaville's lead Marian Gold released a solo album in South Africa called "Prostitute" with STEREO information all the way down to 15Hz! There are others, but that's what I can come up with for right now...

They are the size of refrigerators and weigh about 300 pounds each, BUT you didn't specify a size. As I said, vented enclosures are HUGE for a given Fs.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

haemphyst wrote:

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Nope, there IS fundamental information recorded that low in many recordings. Enya's "The Longships" is a perfect example. 36 inch kettle drums, I believe. Alphaville's lead Marian Gold released a solo album in South Africa called "Prostitute" with STEREO information all the way down to 15Hz! There are others, but that's what I can come up with for right now...

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First of all Haem, what are you doing with hand built t-line enclosures with radio shack subs? I thought you were too good for that? Where's the Wisdom speakers huh? At $50k a pop, why even entertain the thought of building some thing your self?

And by the way, I think you are the only one who listens to what you mentioned there, which is ok i suppose. 

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I'm not too good for ANYTHING that sounds good! No matter what the price. I'm a working stiff JUST like y'all!

At the time the T-Lines were built (finished the NIGHT OF the Northridge earthquake, around 11:30pm - sorry about that ), our T-Line experience was only on paper. The drivers were the best choice we found with what we were thinking a driver needed to do to FIT into an unstuffed line. I would probaby use the same woofers again, they work so well. I worked at RS at the timeof purchase, and I got them for 18 dollars each, and some of my buddies, including Charles from Harman (who is quite impressed with the drivers - technically speaking), still have STACKS of them in their boxes! Their only drawback? Xmax...

As is so often hammered into people here at the12volt, the enclosure and electronics are FAR more important than the driver itself.

They cross-in at 30Hz/48dB, so they will compliment ANY system quite well, as long as that system will actually go to 30Hz, which the Wisdoms do easily. At 30Hz, there is little need for transient response. Oh, and my speakers were the 50 inch, 30K versions, NOT the 50K, 72 inch versions... and I paid SIGNIFICANTLY less than that for them... As I said, Tom is friend of mine... ahhhh, to have friends in the audio business!

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

I would love to see a picture of them if u could post  one bet it does sound awsome! i have four old kicker 18s laying around i would love to experiment with.Anyone ever know what happenr to those 30 plus inch clarions ? P.S haemp i never said it was worthless response. i have just never gotten the chance to feel anything like that. My best attemps have always been with sealed, i have had 4 15s that would still shake down around 7-9 hz in a sealed box .

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rottenbellys 05 crew cab colorado.Pioneer dehp 880prs, kenwood excelon in all 4 doors. Bazooka 500 mono Jl 10w3 in coustom center console box.

Here is a link to my buddy Daves page. This is where most of our information landed. Pics of the subs are about halfway down, and the picture there is the smaller of the two (by about 4-6 inches on EACH dimension) - the one tuned to 13.5Hz...

The pictures of the mains, those are HIS speakers, mine are just the little brothers to those. He has another pair of the 75's in his closet that I am hoping someday to get my hands on... prolly when he moves to Montana!

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Thanks haemp those are awesome. I would love to build one of those t-line boxes for one of my 18s . I have never had the chance to disect one so I could see how there built. If you have any specs or diminsions I could try that would be great.I am putting a shell on my truck and would like to set one up in it.

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rottenbellys 05 crew cab colorado.Pioneer dehp 880prs, kenwood excelon in all 4 doors. Bazooka 500 mono Jl 10w3 in coustom center console box.

Pick up "The Loudspeaker Design Cookbook", by Vance Dickason. You can get the latest version of it a Parts Express...

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

haemphyst wrote:

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I'm not too good for ANYTHING that sounds good! No matter what the price. I'm a working stiff JUST like y'all!...edit... 
Oh, and my speakers were the 50 inch, 30K versions, NOT the 50K, 72 inch versions... and I paid SIGNIFICANTLY less than that for them... As I said, Tom is friend of mine... ahhhh, to have friends in the audio business!

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With out inflection here it is hard to tell who is joking. I certainly was!

I am very interested in all that you provide haem. It's just a little ribbing when bored.

By the way those are some fantastic looking enclosures there. I too would be very interested in a build like that once I own my home

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I truly was joking, and I certainly took yours as joking as well... there was nothing offensive to me in your post. I am sorry if it came across that way in my reply. Some good humored ribbing is quite enjoyable, and is part of what keeps me coming back to this forum.

Thanks for the compliment. Their construction was QUITE involved, and the payoffs are certainly worth the efforts expended. I'll draw a quick diagram of the internals, and post it soon. The numbers I post MAY not be exact, but I'll try to remember them as best I can.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

There's a pic of the internal workings. Keep in mind this is the second one - the "New, Improved" version. The first of the pair, was larger, had slightly more line in it, and was actually tuned lower. We did discover that, while we were aiming for an Fs of around 16 to 18Hz, our Fs was consderably lower than we were actually aiming for. This we attributed to the friction in such a long line. I might also add that hitting an Fs LOWER than desired is not always a bad thing...

The first enclosure also did not have the rounded internal corners, and it is possible to hear this fact. At the lowest frequencies, and at REALLY high levels, you can hear the air turbulence in the line. This happens as the air moves around square corners. For normal listening levels, though, it is a not issue.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Dave didn't Infinity make a version of this in mid 1970s? And aren't these things insanely inefficiant? I think the Infinity was packaged with a 2500 RMS amp for each speaker.

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There is no such thing as free installation!

Well, possibly, as the transmission line is nothing new. The technology has existed for many years, and even Blose today offers something like in the Acoustimass woofer. A woofer driven line, attached to a buried woofer. The sound ONLY comes off the front of the woofer, and is coupled to the room through the line. (Those SUCK by the way... but I digress...)

I am sure there have been many commercial releases of various flavors of TL subs, and I would be willing to bet that the SAF doomed them from the beginning.

Inefficient? Not that I have noticed, specifically. Their efficiency is on a par with a driver in a vented enclosure, just deeper (WAY deeper) response, and better transients. As I mentioned, these are not designed to get even CLOSE to frequencies demanding transient capability, but when we were testing them, they perfomed admirably. These particular systems are not anything special in the output department, but with enough power (350wpc is what is driving them now - Adcom GFA-565 monoblock amps) they have completely useable output capabilities...

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."