15" cinema subs cost how much?!?!

Soldato
OP
Joined
23 Apr 2010
Posts
11,896
Location
West Sussex
Can you guys go into more detail about those competitions?

Sound offs. You had classes and strict rules. So for example in one comp you had to use an amp with no more than 20w per channel (with combined 40w bridged) then design your car around getting as much SPL (sound pressure level) out of it as you could, with that range of amplifier.

However, those like me (who were in the know) would use what was called "the cheater amp" and get banned :D

So why was it the cheater amp? well, there was a certain Phoenix Gold amplifier released many years ago. It was called the Phoenix Gold MPS 2220. It was so over designed and over built (triple gold plated PCB traces) that it could handle about twenty times that power. Then someone realised that if you played with the inside a little bit the amp could run at 1/4 of an ohm.

So think about it like this. The amp is made to run at 40w into 4ohms. However, theoretically (some is lost in heat) each time you half the ohm load you double the power. So at 2 ohms it would put out 80w. At 1ohm it would put out 160w. At 1/2 an ohm it would put out 320. Drop that in half again? you are talking 600 watts.

And that's why it was called the cheater amp and eventually banned from competition :D

I joined Team PG when I got to the USA and met all of the guys who ran it. Awesome bunch. If I can find my old comp pics I will upload them.
 
Soldato
Joined
8 Nov 2002
Posts
3,422
Location
Near Bristol, Uk
Love a good box build! Keep meaning to box up the IDMax 12's for home use (currently on a BK Monolith DF, so no real urgency)

Veneering has always scared me, how hard is it without the clamps/presses etc?
 
Last edited:
Soldato
OP
Joined
23 Apr 2010
Posts
11,896
Location
West Sussex
I won't butter it up mate, it's hard and it's scary.

Most people now use wood glue, but this means you need to vacuum bag the parts and then cut them at 45' and build it that way. Which for me was not an option. As such I used Evo Stik, AKA "Skinhead space costume". It absolutely stunk the house down. Also, once it goes on? that's it. You are supposed to use wooden pieces to line them up but I would have needed loads. So instead of cutting the panels roughly to size I had to leave them over sized which meant I cracked it a lot when rolling/scraping it down. This meant rough edges, which required more work. The reason it looks so much better now is because I went in with a artist brush and some satin black. Wherever there was like, patches between the black stripes I touched in. So its much more seamless than it was.

I did watch a guide or ten. This was about the best.


However, what you don't realise is that he has obviously had a lot of practice and has made his mistakes off camera. So all of mine? I had to fix.

He does make a mistake though. Well, two for me. Firstly he is using a roller to apply the glue. I thought "Oh cool that will make it easy!". Sadly I did not realise that my glue was way stronger than his and my roller head fell apart and stuck to the cabinet. I had to pick it all out whilst it was wet. I had to use the scrapers that come with the glue, and it was unbelievably messy and horrible. There are companies who do iron on, personally I would use that. I highly doubt it has the holding power of what I used, but lets face it you usually just sit and look at speakers and never touch them.

You are supposed to use a scraper to apply veneer. Thankfully my roller had one on the other side. Lots of pressure. A roller (even a wooden one) does not apply enough.


IDK what roller he is using there but it's obviously a special one.

All I know is I never ever want to do it again. Especially not on this scale. That said it was always going to be "the forever sub" so unless someone is crazy enough to try and steal it? it will be lol. I've even got a spare woofer, so yeah for sure never have to do it again.

Had I known all of this? I would have painted the whole thing. That said I am glad I went to hell and back with it.
 
Soldato
OP
Joined
23 Apr 2010
Posts
11,896
Location
West Sussex
Love a good box build! Keep meaning to box up the IDMax 12's for home use (currently on a BK Monolith DF, so no real urgency)

Veneering has always scared me, how hard is it without the clamps/presses etc?

If those are the 12s I am thinking about they were one of the best ever made. IIRC Image Dynamics sold out to China, along with Soundstream and loads of others.
 
Soldato
OP
Joined
23 Apr 2010
Posts
11,896
Location
West Sussex
Ah. It seems I forgot to post up another step. I've been really sick (med change, side effects). I got it done then was supposed to post it when I got home, but was too busy watching Netflix and listening to records :D

Any way, I fitted the legs. It was a lot harder than I planned on it being. Firstly I needed to drill 10mm holes. However, if I had tried to do this it would have blown through into the port duct and looked terrible. I also needed them to be flat inside, and not curved like the tip of most drill bits.

I started out with a bradpoint bit.

EFrDliZ.jpg

Mostly because of the point. This means I don't have to drill a pilot hole. I bought these things.

FWeTQKF.jpg

Which clamp onto the bit and stop it pulling itself in. I pre drilled all of the holes deep enough so that I could use a mill bit. This is totally flat at the cutting end.

kLpz3HK.jpg

Which was locked off at 11mm depth. Then you bolt in the metal receivers, which give you a solid metal threaded hole.

k6r1W4A.jpg

So that is done also. When I am done with the PU clear I will repaint the bottom and entrance to the port duct. That will be the last job to do before packing it up and having someone move it to my place :)

Edit. Oh ruddy heck. My lazy two weeks meant I missed even more ffs.

OK so when I went home I looked at the coffee table this is replacing. It was a bit of a mess tbh. I don't want the top of the sub ending up like that.

So I bought a remnant of ox blood leather.

MCeXls2.jpg

And ordered pinking shears.

D3fBfS8.jpg

I am going to make a sash to put stuff on. The left overs can make some coasters to put my coffee on etc.
 
Soldato
OP
Joined
23 Apr 2010
Posts
11,896
Location
West Sussex
Started working with the leather. Hardest part was getting it squared and learning how to cut it. Turned into a bit of an ordeal, but it's there. I've cut two coasters also, and have loads of spare. I want to test the pinking shears on scrap first, as it is really thick.

rv7MQaL.jpg
 
Soldato
Joined
8 Nov 2002
Posts
3,422
Location
Near Bristol, Uk
If those are the 12s I am thinking about they were one of the best ever made. IIRC Image Dynamics sold out to China, along with Soundstream and loads of others.
These:
WXvhPBFl.jpg
AgcCt6ll.jpg


I used to run 3x of them (IDmax 12 D2) in my classic bug... That was silly loud. rebuilding atm with a pair of infinity perfect 10's.. More of an SQ install these days.
 
Soldato
OP
Joined
23 Apr 2010
Posts
11,896
Location
West Sussex
Final coat of PU is down. I will let it harden fully now before tackling the last black work.

buMlKcw.jpg

Ymub4lT.jpg

As you can see the port is absolutely filthy. So I need to make a tool that I can wrap a cloth around and clean it out properly. I do not want to even think about running a sub in there until it's sparkling. I decorated my room with dust quite a few times in the past.

The leather work is done also.

d2RolFE.jpg
 
Associate
Joined
5 Nov 2013
Posts
1,300
Location
Ireland
Sound offs. You had classes and strict rules. So for example in one comp you had to use an amp with no more than 20w per channel (with combined 40w bridged) then design your car around getting as much SPL (sound pressure level) out of it as you could, with that range of amplifier.

However, those like me (who were in the know) would use what was called "the cheater amp" and get banned :D

So why was it the cheater amp? well, there was a certain Phoenix Gold amplifier released many years ago. It was called the Phoenix Gold MPS 2220. It was so over designed and over built (triple gold plated PCB traces) that it could handle about twenty times that power. Then someone realised that if you played with the inside a little bit the amp could run at 1/4 of an ohm.

So think about it like this. The amp is made to run at 40w into 4ohms. However, theoretically (some is lost in heat) each time you half the ohm load you double the power. So at 2 ohms it would put out 80w. At 1ohm it would put out 160w. At 1/2 an ohm it would put out 320. Drop that in half again? you are talking 600 watts.

And that's why it was called the cheater amp and eventually banned from competition :D

I joined Team PG when I got to the USA and met all of the guys who ran it. Awesome bunch. If I can find my old comp pics I will upload them.

That's going back a long time ago lol. I won every SPL competition that I entered here in Ireland in my old VW Polo. That was back in the early 2000s.

It had

JL Audio E1800D Amplifiers X 4
JL Audio 15W3 Subs X 2
4 X Optima Yellowtop Batteries (Linked by brass buss bars runnings on split charge system)
All Phoenix gold zero point cabling, fuses, crimps, blocks etc.

It also had an SQ system

JL Audio amp (can't remember which model as it was hidden)
Focal Beryllium components
Phoenix Gold 15 channel EQ
JL Audio 8W7 Sub (this thing was awesome for 8 inch, it was about 8 feet long though lol)

I miss those days. I'm sure I have pics of the setup on a floppy disk somewhere :D
 
Soldato
OP
Joined
23 Apr 2010
Posts
11,896
Location
West Sussex
90s for me. I moved to the USA in 2000 and all of my hobbies ended up in the toilet. In hindsight I should never have gone, but oh well we notch it up to experience.

I cleaned out the port (still needs more cleaning from the half way mark back) and repainted the lip. I also painted the woofer hole. Maybe because the set up took longer than the port? or maybe OCD. Pointless of course, but I did it any way lol.

6Vg4jtI.jpg

DS1ypmA.jpg

The PU will be fully cured tomorrow, so I will flip it over and do the bottom for the last time.
 
Soldato
OP
Joined
23 Apr 2010
Posts
11,896
Location
West Sussex
Finished packing it earlier. Covered every face in cardboard, then wrapped it. Then put cardboard on every edge and wrapped it again.

jE5FSYL.jpg

I might have over done it a bit on the wadding......

m3Tn9hj.jpg
 
Soldato
Joined
23 Jan 2010
Posts
4,053
Location
St helens
This is quiet cool and something I was tempted to dabble into in the future.

Brings me back to the old days when I used win trophy after trophy with my SPL car. Man I miss that car. In its prime it hit 167DB, shocked quite a lot of people.
old talkaudio member?

i miss having decent audio weather its house or car. my last set up was 2015 with an ascendant audio mayhem 12

phone mic really makes it sound like complete cack

 
Soldato
OP
Joined
23 Apr 2010
Posts
11,896
Location
West Sussex
OK I am all set.

I cut some graphics using proper 3M vinyl last week. I now have a full assembly kit, minus the woofer bolts which I lost so I have ordered more. Doh.

t2EF5Jf.jpg

Made up a Lapp Kabel with a rhodium plated plug, like the rest of the system.

iET9qoe.jpg

And got some more hard splitters. I have rewired the amp using QED Silver Anniversary cable. The 8AWG ground on there is for the coil bridge wire.

thnIfPM.jpg

I made sure that I sealed everything with liquid tape and wrapped it around the core before hot gluing it all back down.

BAw8QnL.jpg

Lots of mute mat. Twice what I used already. This is for the top and bottom.

ozu9tn4.jpg

And tons of fluff.

Gu076yd.jpg
 
Soldato
Joined
4 Jun 2007
Posts
2,617
Location
Watford, UK
Found it. Knew there was another name for your liquid insulating tape. Silastic. Its a Dow Corning brand name but seems to be used as a general term in much the same way as "Hoover".

I'd call you out on the overkill of your power lead....but it'd be a bit hypocritical! :D
 
Soldato
OP
Joined
23 Apr 2010
Posts
11,896
Location
West Sussex
hah. I made up the power leads ages ago. I made two spare, in case I ever upgraded. Which I did. First another amp, and now the sub. So that was a good plan !

Just for a note. I did not cover all of the cap bottoms and etc in that silastic. They did, I just continued the tradition :D
 
Back
Top Bottom