The Ultimate shootout begins ... - Page 2  

craigsub - When is the shootout scheduled for?

The graph doesn't take into account port resonances, so port size wouldn't matter in these graphs. Port diameter would come more into play when approximating port resonances and port air spead. The point was to show output vs. available xmax with the suggested allignment and ampage. I am sure an 8" or 10" port would suffice.

(having a Homer moment here.........)

Outperforming nearly any OEM product is child's play. That's not the tough part here guys.

The real magic trick is determining how far an OEM can push the size/weight/shipping envelope and still retain a viable customer base.

Take the Acoustic Visions Everest for example. A DIY-OEM bridge offering if I ever saw one. Dual 15" Tumult, quad 18" PR, 10 ft3 enclosure, 410 pounds, beautiful woodwork, attractive design cues, relatively small footprint, no compromises on performance, and a steal for $2,500 ($3500 with suitable amp). And yet did the market embrace this well-conceived and executed subwoofer?

Dual EP600s cost about the same amount of money....and would get stomped by an Everest in any objective performance contest.

And how many EP600s is Axiom selling.......?

You bring up a good point about distortion in the 20-30hz range...but let me play the Devil's Advocate and ask you this: With 800watts to each driver, you're getting close to xmax but never exceeding it really until the low teens according to Unibox. Would this distortion be realistically audible? One can assume distortion in a sealed allignment would be exponentially higher due to Xmax demands in the lower frequencies mentioned. :D

My recollection (which admittedly may be flawed) was that the Denali outpointed or nearly equaled the Plus/2 on music.

Sadly, Kyle is apparently pulling out of the finished subwoofer business because it simply hasn't been a viable product line for him.

Regardless, my point was that the Everest is/was clearly a no-compromise design using what many still regard as the best 15" woofer on the market, and which would more than hold its own against a dual RL-P 15" ported reflex with 8.5 cubes tuned to 17 Hz. And unfortunately it didn't light up the sales charts.

It's not hard to design and build a subwoofer that will easily beat up on OEM offerings - even the relatively big/heavy ones like the EP600 or the VTF-3 HO or the Plus/2. Heck, why not just make it a quad RL-P 15" in 20 cubes with dual 10" aeroports and really add insult to injury?

Where do you draw the line on the size/weight/shipping issue? At what point does this merely become an academic exercise in the laws of physics and cease to become a legitimate comparison between subwoofers that consumers will actually consider purchasing and using in their own homes?

The thought of getting "more" distortion in the 20-30hz area due to a low tuning is silly for a couple reasons. First, you're still getting less distortion than you would in an equivalent sealed design. Second, better to be at risk of getting a little more distortion in the 20hz area with a low tune than in a higher frequency region with a high tune, as the distortion would make itself more audible in higher frequencies.


**Also, just to avoid any potential confusion, this DIY design is definitely NOT a LLT design. The type of design Craig is considering is a traditional ported subwoofer.

This is his 19hz recomendation.

SoundSpliner is a car audio company first and foremost, large and low ported boxes are out of their comfort zone. I'm not knocking them, just throwing that out there. I would rather see one of the current DIY home audio flavors of the month in your shootout, but that is just me. I would love to see how a monster sub compares, and I'm sure I'm not the only one. It would be like leaving out Velo or SVS. :D

Not surprising given that Kyle Richardson is a marketing lightweight compared to Tom & Tom or Ian. Consider policies like:
"International Orders:
Orders are only accepted from the USA. Any orders placed outside of the United States not be honored. "


http://www.acoustic-visions.com/~acoustic/policies/

Geez guys my ears are burning here! :)

Craig, I'm bummed I couldnt help you out with your project but Mike at SS is a great guy to work with and you'll really like the SS drivers. I'm sure your brother will build some nice enclosures for these units too.
Craig is correct, the Kiega did have its limitations and was the weak point in the unit. It's pretty difficult to find low purchase quantity components that work well together all while keeping the price point as low as possible for the consumer.

Ed is correct, I'm moving away from the prefinished products and am going back to my roots as a DIY supplier (supplier for parts and knowledge). It is where I began and where my business works best for both the customer and myself. The Everest was a model in which I never expected to sell many pieces. It was VERY customized for those that needed high SPL in large rooms but still wanted a piece that could be shown off and not hidden away. What it did very well, however, was to get people thinking and talking about what they could make themselves that is similar and I know of many more models that were cloned off of it compared to the amount of Everests that were actually sold. That got me thinking "hmmm, you know what? It's much easier for me to supply the parts and advice for customers to build something similar compared to actually building and shipping one of these 400 lb beheamoths." and that is where we are today.

Totally different companies with totally different goals. One look at the sites and products and that should be pretty apparent. Most DIYers dont need to be "marketed to" and already have an idea of what they want. If they have questions or are confused then they contact me and I will walk them through what products will work best for their situation. No marketing or a sales pitch, just good old fashion advice.

Many of the products I sell are also available in other countries such as Canada, Europe, or Australia and I will not infringe on their territories. With that being said, the US is a large enough area for my business and I have chosen to stay within its borders. Not too uncommon, really. For quite a long time I sold to every part of the world, but the fraud attempts were outrageous, and to be quite honest, I got sick and tired of it and chose to stay with the US.

When I think of you firing up all the woofage you've got there, I immediately envision the power meter in "National Lampoon's Christmas Vacation" when he fires up the Christmas lights. :D

Your neighbors will be falling down the stairs from the massive vibrations, though, instead of the extreme light. Sweet.

when the voice coil heats up, to whatever degree, the Q (peak) of the box will rise in proportion...the higher the temperature, the bigger the peak, and the alignment is becoming unstable...i.e. the frequency response (sound signature) is changing...the resistance is rising and the amplifier chokes.

You also have the notorious BL drop as the excursion increases, this introduces more distortion to the system as you approach and exceed xmax.

This explains why some subs can maintain their composure better than others...cheaper subs will absolutely come apart when driven to high levels...the sound signature completely collapses...in contrast to higher end subs, which use much sturdier drivers, which, in turn, allow them to keep their composure even at insane levels.

The sealed subwoofer, is in no way immune to this phenomena. I guess it would depend on whether you are using an LT or PEQ boost down low. It (distortion) could indeed be worse but it has a constant air spring to fall back on and keep the driver from becoming unruly, thereby tamping down on distortion...



I'm not sure what distortion levels this sub will see but i'm sure there would be a discernible difference in an A-B comparison, albeit maybe at higher levels.

Yes that's the consensus in the DIY arena. I cant think of any recent or past projects that went with the suggested perimeters I see being discussed, but then I don't think Craig is shooting for a real representation of the LLT design?
Good point except to say we're looking at a much higher degree of headroom than what the usual 12" drivers offer, so I favor the lower 16-17 Hz tune myself. I find no shortage in the slam dept. None the same.. It'll be fun to investigate the higher 18-20 Hz tune with some simple PVC glue and see what shakes out?
A very legitimate thought as always Ed, but then how many users do we see doubling up on what they have? Although it's a nitch market per say, would a LLT sono really be that extreme considering all the dual and triplets out there? Shipping such a unit is a breeze and well within the constraints that would discourage such a prospect I assure you.

Just a simple keep it up "Craig" You always have good stuff going. I am going to have to try one of these...
Mike L

"Extreme" is in the eye of the beholder, Steve. Will the market embrace a 20" diameter 56" tall sono LLT? There's only one way to find out. :)

The answer will range from 'not at all' to 'quite significantly'. It all depends on your room size and preferred playback level.

I don't have to be there to tell you a dual 15" reflex in a properly sized and ported enclosure will outperform - in an anechoic environment - your two current favs the Maestro and the DD-18.

And that's what's troubling me about this entire exercise. You have already stated a preference for the sealed alignment. And you have already stated the two best subs you have heard - in your eval room - are the Maestro and the DD-18.

Will the dual 15" reflex necessarily sound better than either in your eval room? Maybe it will exhibit a rising response and sound bottom heavy (something you've already criticized reflex for). Maybe it will have an inferior transient response (defined in this parlance as GD, impulse response, and spectral decay). Sure, it will play louder; you don't even have to build it to prove that - so what's the point of building it at all?

This exercise - in its current form - sounds to me like you are setting up the large reflex DIY for a fall. "It stunned our terrier unconscious at 10 yards during the GP session and it knocked small objects off the shelves during the HT evals, but it sounded bloated on music with smeared details and plenty of overhang and it couldn't hold a candle to the Maestro in SQ".

Looking at DIY as just a route to louder/deeper is myopic. DIY is whatever you want it to be - that is the real beauty of the concept. My suggestion is to play your own hand instead of someone else's. State your known preferences up front and try to do them one better. And definitely take your eval room into consideration and make it an integral part of your design.

Take a page from bosso's playbook and build a dual 15" 2nd order 0.6 Q sealed subwoofer of reasonable size which is designed to start rolling off at the approximate frequency which corresponds to the onset of room gain in your eval room. Then commission Phil Marchand to build a "BOSSIS" electronic interface. I'll let Bosso extole the virtues of such a unit, but in essence it will allow you to custom tailor the frequency response and the roll-of profile of your sealed subwoofer to provide a near-perfect complement to the acoustic transfer function of your room.

That DIY project would get my attention in a hurry.

Wow Ed, fantastic post.

That all may very well be true, but what I believe you aren't taking into consideration is the sensitivity a large and low tuned dual driver subwoofer has. For normal to spirited levels (100db), it's just not seeing much power at all, only around 25 watts. It's only when you start playing at extreme levels that voice coil heat up could become an issue, and extreme bass levels are almost always short peaks, not drawn out passages. So basically what I'm saying is that in a beefy LLT design, it's not an issue.

With an LLT compared to a more traditional ported design like Craig is considering, you'd be suprised how little headroom you are actually giving up in return for better sound quality and deeper extension. The larger enclosure = more sensitivity. It's only a compromise if you don't have the space. And actually, with the designs Craig is considering, I think you'd still get more headroom with the LLT anyway.

Craig, I thought you have some of the best speaker design guys at your disposal? Surely they can come up with a LLT design for you....and surely they see the overwhelming benefits in it compared to what you are considering? Your current design is nothing more than a commercial ported sub that will play louder with slightly less distortion - is that what you want to build?

There have been almost 0 traditional ported subs like this built in any of the more knowledgeable DIY sections that I know of for at least the past nine months, and there is good reason for that - LLT is better. If you had a better history with testing, I'd help you design this thing from start to finish....but as it is, I feel my efforts would be in vane.

Okay........for us dummies.......what's LLT?

I know you guys have some history but lets try to keep this civil at least until page 5, or after the results are posted. :D

craigsub- What kind of box are you personally envisioning?

My abreviation for a large and low tuned ported subwoofer is a bit more selective in requirements than a standard extended bass shelf subwoofer. In addition to the definition of an EBS, with a LLT, the port diameter must be at least 6", the first port resonance shouldn't be below 180hz, the tuning will be below 17hz, and it should be amp limited so that overexcursion can't be reached until an extremely low frequency so that a high pass filter isn't needed.