Big Sub update.

[Jerry]

So I saw a few WOWs on the last big sub pictures. Here Is the picture of the EarthQuake Holly-S. You'll be able to figure what the S stands for.

This sub in the picture is called a 15" allthough it measures 16.5".

Factory specs are 14,000 watt rms continuos, 28,000 watts for short duration, 112 LBs, 4" of cone travel. We've seen near 160 DB from this sub in our NW record holding mini truck. Enclosure at 28 CU. Ft. tuned to 50 HZ.

The smaller sub next to it is from yesterday diary.

Here is a 20 KW amp I built a few years ago. Its 2 chanels at 10 KW each. Its class A/B. .25 ohm stable. 96 volts each rail (192 volt swing).

Its about 4ft long weighs 135 LBs.

We are an EarthQuake dealer. A freind sign maker made this street sign to go above 1 of our demo rooms.

Here's a stack of 15 each 15" subs in tubes in another demo system.

OK sorry just got side tracked.

Anyway it will be harder to kill the big sub. However EQ has just introduced a 20,000 KW amp that may do peakes of 25 to 30 KW. That might do it?

I'll start taking the 2 KW sub apart in a day or 2.

                         JK TAS Jerry

[willib]

Holy ' S '

4 inches of cone travel , thats amazing.

[A6D9]

does the "S" stand for sexy?   cuz damn that is some sexy equipment there  

[Warrior]

WOW Jerry, that's an amazing sub!!!. I wonder what kind of car amp (batteries and alternators) do you need to drive that thing?

I really like your 20Kw homemade amp!!! That's awesome!!!

Wish I had the knowledge to build such a thing (the largest amp I built was 50 watts & assembled a couple of 125 watt kits).

You seem to know your stuff in the car audio business, is it OK if I contact you via e-mail for a couple of equipment related questions?

Thanks,

Warrior

[Bruce S]

Jerry;

  Quick question on the amp? how's the harmonic distortion with using the solid states?

I would think that at those freqs that even the tord would begin to get into a ringing harmonic. I am using wolverines 12" and tubed amps 1 for each channel  and I've had had problems in the upper volumeric ranges with harmonics.

OR are these mostly out-of-doors units. There I don't have the problems. I do like watching Jurrasic Park 1 and seeing the house windows viberate when the T-rex comes calling, even the plexi moves:--)

x2 WOWOWOW on the big brother:--)

Bruce S

[Jerry]

Hi Warrior.

Thanks for the kind words. Well my first job as a mobil car audio tech (stereo installer) 1975. I had actuly been building amps an such from the arly 60s.

I pin point my begining into electronics at 1958 with crystal sets, one tube radios and such. Then on to military electronics and college.

Yep ask away on the equiptment stuff. I'll do my best to help.

                              JK TAS Jerry

[Jerry]

Hi Bruce.

At this power level I only use amps like this for low frequencies. The amp is filtered and operated from 20 hz to 250 hz.

Mid high frequencies go to small amps typicly between 80 to 100 hz. I'm most of my personal audio systems I use 2 EQs. 1 for the lows and 1 for the stuff above 80 hz.

Solid state amps have odd order harmonics tube amps amplify with even order harmonics.

Belive it or not there is a much larger debate between the tube guys and the solid state guys then there is between the star guys and the jerry rigged guys. That debates been going on 50 years or more.

The amp in the picture is not the version I use in car audio.

However the car audio versions rail voltage is provided by 16 small GM side post car batteries. These batteries are wired in sires. There is a tape in the center. This provides a 96 volt positive rail voltage and a 96 volt negetive rail voltage. This eliminate the need for a high speed switching power supply and its harmonic isues. It provide an extreamly stable amp power source. This intern musters up an ungodly damping factor. And with 60 T-03 output divices directly mounted to the heat sinks with no thermal insulator and the heat sinks carrying the rail supply ( carfull don't tuch the heat sinks) The curent capacity and low impedance capacity are awsome.

These amps are used in car audio. We've set a few NW SPL records in the past using them.

When you couple one of the amps to 16 twelve inch subs in the best posable PNR style flaired slot ported enclosers rated over 1 KW each in a fullsize GM van the DB#s get fairly high.

We hold 4 NW SPL records and 1 3rd place world record.

We also do SQ systems. More info on those later. I just got the word, I gota run.

                        JK TAS Jerry

[Warrior]

Jerry,

You have mail...

I sent it witht the Subject: Fieldlines-Car Audio Questions

Thanks,

Warrior

[Jerry]

I used some 1/4" all thred as jacking screws to pop the backing plate off.

It was very hard to get the wrench onto the nut. Even though these are ceramic magnets working close to them was very dificult.

As the space got wider I incerted wood blocks.

Finally got the back plate off. Its sweet!

I stacked the magnets up 3.5" diameter and 12.75" long. I thought these would be doughnut type but the are solid discs.

At this point I'm not sure what I'll do with them. I brought them in the house, as I passed about 6FT away from the kitchen TV my wife said hey you turned the TV green.

I took the magets to the bathroom scales. I was about to set them on the scales when the scales jumpt off the floor from about 4 inches. They weigh in at 22 LBs.

I'll take the plate off the speaker basket. These are a nice set of 10.75" discs.

The 15" basket will be a nice support for a 12" dual rotor.

                           JK TAS Jerry

[chadking]

Wow.  That sub and amp are amazing.  20,000w and 4 inches of cone travel are hard to fathom!