These guys seem to have an 18" loaded horn that works...

[Spire]

http://www.voidaudio.com/product_detail.asp?id=63

http://www.voidaudio.com/pdf/plots/Psyco%20Sub.pdf

If their SPL chart is measured correctly (and honesly) i want a clone of those....

105bd at 40hz 1w 1m. Horn length is about the same as a T48, cabinet is close to the same size, 48X25X30 ish.

Anyone have lots of extra money and want to tear one apart?

[Turntablist]

I'd say the specs are BS. There are limits for how high sensitivity you can get and how low you can go within a certain packspace and if you try to load the cab with an 18" driver you will have an additional chamber volume that will shortchange the sensitivity/packspace ratio as well.
The specs are all a matter of how much the marketing team can get people to misinterpret them.

[Bill Fitzmaurice]

If their SPL chart is measured correctly (and honesly) i want a clone of those....

You'd better clone yourself while you're at it, at least twice, because it will take at least three of you to schlep that 225 pound cab about.

[Greg Plouvier]

I'd say the specs are BS. There are limits for how high sensitivity you can get and how low you can go within a certain packspace and if you try to load the cab with an 18" driver you will have an additional chamber volume that will shortchange the sensitivity/packspace ratio as well.
The specs are all a matter of how much the marketing team can get people to misinterpret them.

Why don't you send a copy of your comment to Void and see what they have to say instead of spouting BS of which you have no 1st hand experience. Void is a well respected company and like all companies of that caliber have undoubtedly worked very hard to get where they are. This constant bashing of companies that have years/decades of R&D behind their products is getting a little tiring.

[gdougherty]

I'd say the specs are BS. There are limits for how high sensitivity you can get and how low you can go within a certain packspace and if you try to load the cab with an 18" driver you will have an additional chamber volume that will shortchange the sensitivity/packspace ratio as well.
The specs are all a matter of how much the marketing team can get people to misinterpret them.

Except, what's noted is actual response numbers taken from a sensitivity chart. If the 5" voice coil can handle a decent amount of power, it's a very impressive sub. It's also more than twice the weight and not something I'd care to move about.

Seems like you could build the same thing with better horn path bracing, 1/2" ply and a lighter 18" driver to get similar performance with much less weight. It's pretty similar to an 18" loaded version of my T48's, though they're using heavier wood and a single brace to reduce flex and vibration. With a 5" voice coil, I'm guessing that's a beast of an 18"er.

[Spire]

Seems like you could build the same thing with better horn path bracing, 1/2" ply and a lighter 18" driver to get similar performance with much less weight.

thats what i was thinking/hoping.

[Bill Fitzmaurice]

In Void's defense they have a chart, which is more than most manufacturers do. In Turntablist's defense it does look a bit suspect. Using the Void driver, horn length, horn mouth and total box size this simulation is about as good a result as I can get:



It doesn't jibe at all with the Void chart below 60 Hz. OTOH, this one, of a stack of four, comes very close:



Not that I'm accusing Void of misrepresentation, but such things have been known to happen. For years EAW had a chart of one of their basshorns that defied explanation, until it was finally revealed that it was a four cab stack chart. Shortly thereafter said chart was removed from the data sheet.

It used to be that you could get away with claiming just about anything you wanted, as consumers had no way of verifying or debunking those claims. That's no longer the case, what with modeling and measuring software available to all.

But as to using an eighteen my view remains that there's no advantage to it, and more than a few disadvantages, so I'm still not going there.

[Ron K]

I'd say the specs are BS. There are limits for how high sensitivity you can get and how low you can go within a certain packspace and if you try to load the cab with an 18" driver you will have an additional chamber volume that will shortchange the sensitivity/packspace ratio as well.
The specs are all a matter of how much the marketing team can get people to misinterpret them.

Why don't you send a copy of your comment to Void and see what they have to say instead of spouting BS of which you have no 1st hand experience. Void is a well respected company and like all companies of that caliber have undoubtedly worked very hard to get where they are. This constant bashing of companies that have years/decades of R&D behind their products is getting a little tiring.

+1 Well said.Void is a decent company and Rog Mogale is highly respected in the industry.

[Turntablist]

I'd say the specs are BS. There are limits for how high sensitivity you can get and how low you can go within a certain packspace and if you try to load the cab with an 18" driver you will have an additional chamber volume that will shortchange the sensitivity/packspace ratio as well.
The specs are all a matter of how much the marketing team can get people to misinterpret them.

Why don't you send a copy of your comment to Void and see what they have to say instead of spouting BS of which you have no 1st hand experience. Void is a well respected company and like all companies of that caliber have undoubtedly worked very hard to get where they are. This constant bashing of companies that have years/decades of R&D behind their products is getting a little tiring.

+1 Well said.Void is a decent company and Rog Mogale is highly respected in the industry.

I have modeled a lot of drivers in hornresp and tweaked every last bit out of them but I have never ever comen close to the claimed performance of Void's sub.
If I have heard the sub or any of their other products or any other companys products for that matter don't matter. Like I said in my first post and as Bill also pointed out, the claimed performance isn't possible within the packspace. Period. It doesn't matter who the manufacturer is.

Do you still think that I should send a comment to Void about the claimed performance?
I don't understand why you would protect companys that give out crooked specs other than with something like "Said company has to get people to misinterpret the specs because every company does it". No company has any magic dust to sprinkle over their products.

[Radian]

Do you still think that I should send a comment to Void about the claimed performance?

I think you still should, with tact of course.

When he was younger, my father wrote a letter to Boyer candies to tell them how much he loved Mallo Cups. They ended up sending him a box full in return. Last summer I bought new wiper blades for my car which started to chatter within the first month of use. I called the company, after discussing the issue they sent me a new pair, voila'. The new pair still sucked, but I give the company props for trying their best to stand behind their product.

Sometimes, it's not always about performance nirvana.

[Greg Plouvier]

Yes - I think you should contact them. I don't think it's right to sling accusations without at least getting their input 1st. I'm not "protecting" Void as you suggest. Running their driver and and your parameters in hornresp doesn't take into account the many years of experience, actually prototyping designs, and variations inside their box which you have no awareness of. I'm not saying their box does or can't do what they claim - because I've never heard one or talked with Mr. Mogale. Proof is in the pudding - not staring at a hornresp chart and saying - oh that can't work. The main thrust of my comment was: the bashing of other manufacturer's gear on this or any forum is uncalled for. It's tiresome. Is there really any point to it?

[Ron K]

Yes - I think you should contact them. I don't think it's right to sling accusations without at least getting their input 1st. I'm not "protecting" Void as you suggest. Running their driver and and your parameters in hornresp doesn't take into account the many years of experience, actually prototyping designs, and variations inside their box which you have no awareness of. I'm not saying their box does or can't do what they claim - because I've never heard one or talked with Mr. Mogale. Proof is in the pudding - not staring at a hornresp chart and saying - oh that can't work. The main thrust of my comment was: the bashing of other manufacturer's gear on this or any forum is uncalled for. It's tiresome. Is there really any point to it?

To add to what Greg is saying, Rog Mogale may have used Akabak instead of horn response and according to Tom Danley, Akabak models quite differently then Horn Response.I don't know the specifics of that debate but I do know he made a point of it when modeling his tapped horns and some discussion regarding those designs. Whether or not that has any bearing here is not the debate however.

Perhaps the driver is a special design for the box similar to the Lab12 sub driver? Perhaps the measured result is after processing? Maybe the raw response is actually a much higher spl with a low end stepped response and the result is EQd to be maximally flat resulting the the -3db spec?

The real issue is without knowing exactly what is used in the box and what Mr. Mogale has actually done in his design even if its a mistake in his marketing literature, it's quite unfair to call shenanigans without at least consulting the designer first! Knowing what I know of Mr. Mogale he has always responded to his users questions. His marketing or sales or service dept. may pick up that ball first but again I would consult them before making any claims.

It sort of the same thing and attitude that is represented by a few on some other boards about Bills designs and IMHO if you haven't bought or built, heard,used in the real world and accurately measured some designs it's going to be hard to convince someone else you're opinion is worth much irregardless of your level of the science of physics!

[Greg Plouvier]

+1 Thank you Ron!

[Bill Fitzmaurice]

according to Tom Danley, Akabak models quite differently then Horn Response.

It used to, but not anymore. Where response is concerned HornResp is now just about as accurate as Akabak, and is infinitely easier to use. Akabak offers some more advanced features, but McBean issues improved HornResp versions on average every six months, and I expect he'll eventually meet or exceed Akabak.

[Ron K]

according to Tom Danley, Akabak models quite differently then Horn Response.

It used to, but not anymore. Where response is concerned HornResp is now just about as accurate as Akabak, and is infinitely easier to use. Akabak offers some more advanced features, but McBean issues improved HornResp versions on average every six months, and I expect he'll eventually meet or exceed Akabak.

Thanks for that update.

To be clear I wasn't saying this to point at the modeling but only to use it as a "possible" point of reference that may be overlooked along with many others reasons that may be out there. What those are exactly we could all argue till Clairs stops building their own boxes!

Point is the bashing is actually pointless unless those participating have some real world experience with the actual products being discussed.You just dont know till you look under the hood and take her for a test run! The rest is Car and Driver hoopla!