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[Walt de Jong]

We had our own Subwoofer shootout here in Holland! There were two LAB's present, 4 Punishers and loads of reflex boxes.

Too bad the aluminium acces panels on the LAB's had some air leaks so they didn't perform like they should be the experts told me. This day the stack of 4 Punishers was the loudest measuring 130db at 3 metres distance

The 18" basreflex boxes also did a good job! The horns project the sound more far but up close the BR aren't that bad really.

http://www.vitality-show.nl/fotoboek/album31?page=2

Punisher stack: http://www.vitality-show.nl/fotoboek/album31/IMG_8408

Best regards,

Walt

[Graeme Goodacre [Centauri]

Walt wrote on Mon, 22 November 2004 08:44

This day the stack of 4 Punishers was the loudest measuring 130db at 3 metres distance

Yes, but at what frequency ?  130dB at say 100Hz isn't much use to someone who is looking for 130dB at 30Hz....

Where there any response / distortion measurements taken at this meeting? Photos look like meeting was held in tin shed - was testing done inside or out?

Would be good to have organised testing and evaluation of all the different DIY subs and compare to some representative commercial ones, but that would take a LOT of organising....

Cheers
Graeme

[Walt de Jong]

Hello Centauri,

I don't know which frequency. I used a dB-meter to get those numbers, I set it to C-scale. The Punishers were extremely loud above 50Hz. A lot of acoustic power out of a small stack.

Best regards,

Walt

[Michael_Elliston¶]

It looks like,from the graphs,that most units had highest output near 60hz with some getting near 40hz. The uncalibrated wonky low level measurements are hard to see while being close to the noise floor

 http://www.speakerplans.com/forum/forum_posts.asp?TID=957&am p;am p;PN=1&TPN=2

[Steve Shafer]

Walt:

Your punnisher's look like a very well designed and built set of subs/ Congrats.  Do you have any plans of doing something like your punnisher with say a 15" driver and having considerably more LF extension?  

Have you ever tried loading the Eminence Lab Sub 12" in a punnisher to see what differences it would make?

thanks

steve s  

[Graeme Goodacre [Centauri]

A 15" driver will not automatically gain any LF extension - this can only be achieved through a longer horn path (or bandpass chamber tuning with tradeoff of LF efficiency as in the Tubas).  Once you drop a 15 in, you have automatically taken up more space for the driver itself as well as the usually larger required rear chamber, thereby reducing the room available for horn within a given size cabinet.  No doubt the Ciare driver can be operated a lot lower than in the Punisher, but it will require a longer horn and therefore larger box.

I don't think the Lab12 would be a good choice for the Punisher as its Fs is considerably lower than the box tuning and would result in excessive response ripple and possible excursion limits.  The Lab12 is really happier in a 15Hz horn.

Cheers
Graeme

[Michael_Elliston¶]

Hi Graeme.
I think that going from a 12" to 15",immediately requires a larger horn,although with the same length,it goes slightly lower.

Throat area has to be re adjusted,meaning the horn is probably twice the area at the start,making it larger,not even including the larger Vrc etc.

Do you think,that the small rear box contributes to significant 2nd harmonic distortion at bass frequencies,like linkwitz suggests on sealed boxes? Or are the 2nd harmonics,atleast in the upper bass not transmitted effectively through the large Vtc.

Or is the distortion products mainly due to driver BL nonlinearity?Youd think so ,because the passband is so narrow,and near the increased Fs(fcb i guess)due to small Vrc. Why not use a driver with both SFG and shorting rings to help out these areas? As you know,my 2226 has these,and Il be building,and measuring(have to save for ECM8000)

What about Sven,he thinks that the labhorn has a rubber throat-is this true? if so,does this contribute to lower system distortion?

Cheers!

[[x]]

I would expect the Punisher to impress with its hard-hitting sound. They'd be great for outdoor shows and dance music, and indoor shows where extremely low LF is not required, such as rock bands.

Also, check out the video on this page: http://www.speakerplans.com/forum/forum_posts.asp?TID=957&am p;PN=1&TPN=2

[Michael_Elliston¶]

BHFProfessional       
I would expect the Punisher to impress with its hard-hitting sound. They'd be great for outdoor shows and dance music, and indoor shows where extremely low LF is not required, such as rock bands.

Certainly. I saw the video- Dance music

[Graeme Goodacre [Centauri]

mike_nz wrote on Fri, 10 December 2004 16:07

Certainly. I saw the video- Dance music

Lower frequencies move sawdust further...  

[Michael_Elliston¶]

my jbl horn is 34hz loading,~28hz F3.
Il have to carefully remove the +6db preset boost on my plate amp -it fits in the response of the current EBS setup,but will cause a bloated response probably with the horn

Do you know about DIY digital delay? Im trying to find a chip i can use,to delay my mains,because il have 3.2metres of path length

Cheers!

[tdsje]

The shootout was great ! Exept that my labhorn(s) where not 100% airclosed   But it has been fixed now, I am ready for the 2005-version. Next time our shed will be available again. I'll hope my L-15 horn will be ready after then, i will get an prototype, and the LAB + Modified MT122 stack   Also de Xtreme-SP-Horn willbe finished to. Anybody interested in coming to the Netherlands  

[Wayne Parham]

Hi Mike,

You can use a bucket brigade chip for an easy DIY delay.  But a DSP implementation is better.  You could probably setup your PC and sound card to do the job.

Just a thought.

Wayne

[Too Tall (Curtis H. List)]

mike_nz wrote on Fri, 10 December 2004 00:50

Do you know about DIY digital delay? Im trying to find a chip i can use,to delay my mains,because il have 3.2metres of path length Cheers!

If you want to tackle a DIY project then more power to ya.
   Otherwise I would look for used digital reverb/delays on ebay. They have come way down in price over the years.
   Two things you need to check are sampling rate (some older stuff is around 20khz sampling rate or 10kHz frequency response) and more important that it has enough resolution. Some might only change in units of 10ms.
   A GOOD bucket brigade will work depending on how picky you are. My understanding is that Meyers used bucket brigade type delay for years on all their speakers, but I would not expect the same quality in a stomp-box delay for a guitar effect.
Too Tall

[Michael_Elliston¶]

Hi tootall

Yeh,problem is 'ebay' here simply doesnt have the same variety of goods,with only 4million people.
-And in the end,all I need is a delay,not EQ/limiting/etc

I might build it,and find that i dont mind the sound when i sit close to it at 130db,I might not notice the slightly early highs

Cheers
Mike.e

[Michael_Elliston¶]

Hiya

Is the Xtreme-SP-Horn with a ciare12"?

Cheers

[Michael_Elliston¶]

Yeh im having trouble finding the chip I want.

I usually use my PC for my source,so using a delay on there could easily solve it. IT probably has some delay already

You never know,I might build it,and due to room distortions might not even care about the delay if I sit a metre  closer to the sub  

Cheers!