# 130db with old school set up



## haromaster87 (Jan 20, 2012)

Hey guys,


So quick back story. I'm 20, and missed out on the old school years of car audio. I am avid into vintage hi-fi home stereos, but I'm pretty new to good car audio. I'm currently working on my first car stereo, and I'm going old school on it. The new school stuff just doesn't make it for me. Like I do with the home stereos, I find the creativity and quality associated with the vintage equipment much more appealing. I'm putting it in my 1984 Mercedes 300D. I wish so bad that I had the resources to do a crazy build on it, but unfortunately I have to try and keep it simple and basic for now, and I have to allow the car to remain functional. I have a thread in the build advice section, so I'm not just coming here to look for that.

What I'm more looking for is some people with some knowledge/experience with the older equipment I want to use and get some general advice. I also want to find out if my goals that I kind of dreamed up with no real knowledge of car stereo. I would love to be able to hit 130db. It seems for certain set ups, that's nothing. But from the home stereo, I know it's not just nothing to make a 130db system. 

I have to keep my subwoofers in the trunk, and the only access between my trunk and and interior is a port that I could create with the hole in the deck for the factory First Aid kit. I have yet to determine if that would even be worth it or useful, but that's for discussion in another thread. Anyway, I'll be working with 2 MTX 12" Blue Thunder subwoofers. They are the version with the black cone and the dust cap that looks dented. I believe the ones I've bought are 4ohms each. I want to run these with a Soundstream Reference 2.640 which should allow me to wire them at 2ohms, and get 320(ish) watts to them. I believe I will be using them in a ported enclosure, but that has yet to be fully determined. 

Inside I will be getting an Alpine cassette deck and running it to a 4ch amplifier. I'm probably going to pick up a SoundStream REF for that too. Not sure which one yet, but one that can push about 70-80 watts or so at 4ohms. I will have a 6.5in component each front kick panel with the tweeter in the dash, probably aimed towards the listener. And on the rear deck, I'm going to fill the 5.25 spots with the 5.25 version of the the component speakers, and I'm going to mount the tweeters to those on the B-pillar, facing the listeners in the rear seat. These will be more for when I have people riding in the back. 

So, I know there's quite a bit of variables in my plan so far, but is there any way that I could hope to come close to my goal or do I need to set more realistic goals? I feel confident so far that for a fairly simple install, it will sport a nice, quality sound, but I'm a little antsy about the SPL's I can expect. Don't ask why. lol I'd honestly be surprised if it could come close, but I'm optimistic. Even if not 130db, I feel like I can expect a pretty loud system with good balance if I do it right. It will probably be impressive to my friends and stuff, seeing as their idea of a good car "system" is some crummy "subs" wired in with an otherwise stock stereo. lol I plan to do all of the necessary insulation of the body panels and other supporting mods. Again, details for that can be discussed in my other thread. I'd just like to kind of introduce myself in the old school section and get some knowledge from the old school guys. 

Thanks!


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## theeaudioboy (Jun 3, 2011)

hi these are the BTL series i believe is what you have ! well they did come in 4, 8 and 12 ohm so id check and see ! with the inverted dust cap, is what thats called ! anyways i know from experience owning 4x of these 12"s and 2x 15"s that i still have, bought new back in late 90's ! the wattage is 250 rms 500 peak ! the SS ref you have will push them great even though its rated little more wattage ! i would get the SS ref 4.400 to match !

I would cut through the rear seat and do a port through ! i know some of those older benz had a fold down armrest in center rear ! dont know if your model does but you can go to World Upholstery & Trim, U.S.A. Manufacturer of Auto Uphosltery, Carpet, Convertible Tops, Car Seats, Headliners & Door Panel Parts for Mercedes, BMW, Porsche, Jaguar, Fiat, Ferrari and Alfa. 800-222-9577 to get replacement seats for mercedes ! but a mid size ported box cut through rear seat would be good ! i got 139 outta 2x in a mid size ported enclosure ! but was also in a small ext. cab truck ! but this would be the way to go verses port through rear deck ! 

these are good old school subs though !!! if anymore questions you can send me a direct message ? ive used many MTX products since 94' to now !


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## Wesayso (Jul 20, 2010)

Good to see your new plans... you might be able to hit high numbers if you use the cabin gain to your advantage. But I suspect it would give you a bit of one note bass kinda setup. Cabin gain is great in a car but I'd use it to get good overall responce.
To hit high numbers you might want to look in the SPL forums.


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## smgreen20 (Oct 13, 2006)

A ported box will be your best bet on the getting to the 130dB mark. If the only means you have of getting sound into the cabin is through said hole, you might even want to go with a 4th order bandpass box. 130dB is achievable and doable with those subs. Google "WinISD free download" (www.teamlinear.com I think???) and DL the beta and plug in the T/S parameters to help design your box. 

I had two 12" LANZAR Pro series subs in a '90 Chevy Beretta and was hitting 127dB, but it I would've tuned higher and had a bigger box I could've cleared the 130 mark easy.


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## theeaudioboy (Jun 3, 2011)

heres my 12" BTL's have the 15"s as well and 4x of these ! but the 15"s are buried deep in the walk in closet ! http://www.diymobileaudio.com/forum/attachment.php?attachmentid=33525&stc=1&d=1327234102
these should be the same models you have from what you described !?


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## Venomized (Dec 21, 2011)

Back in my teen years I ran a 139.5 with 2 JL 15W0-4 in a sealed box running off a punch 60ix that ended up frying during the run, in the trunk of a 91 cutlass coupe. I put it on a kicker ix402 after and still hit a 137.2.


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## haromaster87 (Jan 20, 2012)

Hey guys, Thanks for all the replies. I'm pretty excited to know this is doable with what I have so far!


Wesayso said:


> Good to see your new plans... you might be able to hit high numbers if you use the cabin gain to your advantage. But I suspect it would give you a bit of one note bass kinda setup. Cabin gain is great in a car but I'd use it to get good overall responce.
> To hit high numbers you might want to look in the SPL forums.


Yeah man, I decided I needed to revise my original plan after I did some more reading. I'll have to mess with that cabin gain and see what I can do with it.



smgreen20 said:


> A ported box will be your best bet on the getting to the 130dB mark. If the only means you have of getting sound into the cabin is through said hole, you might even want to go with a 4th order bandpass box. 130dB is achievable and doable with those subs. Google "WinISD free download" (www.teamlinear.com I think???) and DL the beta and plug in the T/S parameters to help design your box.
> 
> I had two 12" LANZAR Pro series subs in a '90 Chevy Beretta and was hitting 127dB, but it I would've tuned higher and had a bigger box I could've cleared the 130 mark easy.


 Hmm, I didn't even think of using WinISD. I used to use it for home audio subs. I'll definitely have to look into that. Thanks for the tips!



theeaudioboy said:


> heres my 12" BTL's have the 15"s as well and 4x of these ! but the 15"s are buried deep in the walk in closet ! http://www.diymobileaudio.com/forum/attachment.php?attachmentid=33525&stc=1&d=1327234102
> these should be the same models you have from what you described !?


Hey man, those look pretty close to it. Thanks for the info on them. I sent you a pm to further discuss them. Thanks again!



Venomized said:


> Back in my teen years I ran a 139.5 with 2 JL 15W0-4 in a sealed box running off a punch 60ix that ended up frying during the run, in the trunk of a 91 cutlass coupe. I put it on a kicker ix402 after and still hit a 137.2.


Dang! That's really loud. Nearly twice as loud as I want to go. lol I guess two good subs can do quite a bit of work if implemented right. I'll just have to keep planning everything out right.

Now, as for my enclosure. I don't have any access to wood working tools and it might be hard for me to build a box. Are there any decent, premade boxes I could look at? I mean, if I found one that fit the parameters I needed, I could get it and add some bracing or something if needed. I see lots of pre-built dual 12" boxes that look decent, but I know how that can go. haha


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## Cancerkazoo (Jul 21, 2006)

130dB should be easy. I hit 127 in the 1-50 watt class in the 90's with a Orion 12" XTR DVC on a 225 HCCA in a 1.25cuft sealed box in a Fiero.


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## Venomized (Dec 21, 2011)

haromaster87 said:


> Dang! That's really loud. Nearly twice as loud as I want to go. lol I guess two good subs can do quite a bit of work if implemented right. I'll just have to keep planning everything out right.
> 
> Now, as for my enclosure. I don't have any access to wood working tools and it might be hard for me to build a box. Are there any decent, premade boxes I could look at? I mean, if I found one that fit the parameters I needed, I could get it and add some bracing or something if needed. I see lots of pre-built dual 12" boxes that look decent, but I know how that can go. haha



My enclosure was custom built just for those subs. The shop that held the event was who built it. It did great for the years I had it and then I had a psycho ex that stabbed through both subs multiple times so they went in the garbage.


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## haromaster87 (Jan 20, 2012)

Venomized said:


> My enclosure was custom built just for those subs. The shop that held the event was who built it. It did great for the years I had it and then I had a psycho ex that stabbed through both subs multiple times so they went in the garbage.



Oh geez! With some of the girls I've dated, I feel like that could happen to me. haha

So I actually started pulling at body panels and realized a mild flaw in my plan. There is pretty much no place for 6.5's up front. So I revised my plan and I'm looking for some critique on this. So I can still fit the 6.5 components in the back and I had an idea. I can get 6.5 components, and put the midbass drivers on the rear deck, and run extra wiring for the tweeters and mount them up front(I have the perfect mounting spot) and then I could get some 4in mid range drivers for the dash. Just single mid range drivers though, no coaxials or anything. 

So I'd have my tweeters up front aimed at the listener, 4in mids for the upper mid range in the dash, 6.5's on the rear deck for the mid bass, and then my subwoofers in the trunk. 

I posted this in my thread in the build advice section pertaining to how that would affect my SQ, but since I was asking about SPL in this thread, I figured I'd come in here and mention it. As long as I make sure to crossover the cabin speakers and keep the lower frequencies away from my cabin speakers, should this mild change in speaker set up change my SPL expectations too much? 

Also, while I'm speaking about crossovers, the components I'm looking at have the crossovers in the tweeters, and then the Soundstream Reference amps seems to have crossover/filters in them. Based on this, will I still need an external crossover?


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## neuspeedescort (Feb 23, 2010)

Venomized said:


> Back in my teen years I ran a 139.5 with 2 JL 15W0-4 in a sealed box running off a punch 60ix that ended up frying during the run, in the trunk of a 91 cutlass coupe. I put it on a kicker ix402 after and still hit a 137.2.


i have to call BS on this. sorry man. back in 99 i had 2 fosgate dvc 15's off a power 500a2 and could only pull a 140.7 out of a hatchback. no way in hell did you yank a near 140 out of a trunk and a 60ix.


NEUMAN


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## jcorkin (Jan 26, 2012)

139.5 is possible it all depends on where the mic was placed, last time the mic was calibrated, brand of mic, etc. i hit 139.1 in 2002 off of 2 orion xtr3 12s in a very very tight sealed enclosure running off of a power [email protected], i think the mic needed to be calibrated as i usually ran around 135-136 on other mics, also this was in the back of a 1993 hatchback ford probe. it really comes down to the mic and enclosure specs plus placement on this one.


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## Jake the SSnake (Jan 29, 2012)

neuspeedescort said:


> i have to call BS on this. sorry man. back in 99 i had 2 fosgate dvc 15's off a power 500a2 and could only pull a 140.7 out of a hatchback. no way in hell did you yank a near 140 out of a trunk and a 60ix.
> 
> 
> NEUMAN


Who knows what the calibration on that mic was like. I dont put any faith in #'s from back then. We had all kinds of people hitting 145+ back then, and since upgrading to a TL, very few have broken 145 with most having trouble getting out of the 130's


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## xsdb1 (Jul 31, 2011)

deep in my files I seem to remember having a design straight from orion for 2x xtr 8a in a bandpass enclosure for the older camaro/firebird that pretty much guaranteed mid 130s off a mid sized amp. I'll see if I can dig it up. Also, did 147.8 at a db drag with one 15" gz nuclear and an old earthquake shredder amp in 1997 with wayne harris at the controls!


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## theeaudioboy (Jun 3, 2011)

Jake the SSnake said:


> Who knows what the calibration on that mic was like. I dont put any faith in #'s from back then. We had all kinds of people hitting 145+ back then, and since upgrading to a TL, very few have broken 145 with most having trouble getting out of the 130's


 
ya i know all to well about #s being higher yrs ago before they started really using the term labs ! people all the time would claim to do 150s when they were they actually were low 140s at best ! and knew few to many people who claimed to do 140s with old 10"s or 12"s in sealed boxes !? but put any of those systems on a TL and see there #s !? : ) as for doing 140 outta a trunk !?


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## PPI_GUY (Dec 20, 2007)

I did 126 on an AudioControl (I think, it's been a loooong time) setup back in '89 using four Kicker Free-air 10's mounted behind the rear seat of a '79 Trans Am and powered by a single RF Punch 45. It was poorly installed and sounded like crap but, it was my first system and I thought I was boomin' back then!


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## DevanTheDude (Dec 31, 2009)

Not sure when they changed this, but most older Mercedes have the gas tank mounted behind the rear seat with a solid sheet of steel separating the interior cabin from the trunk. This will drastically reduce the amount of volume you get out of your subs. May want to check that out.


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## haromaster87 (Jan 20, 2012)

DevanTheDude said:


> Not sure when they changed this, but most older Mercedes have the gas tank mounted behind the rear seat with a solid sheet of steel separating the interior cabin from the trunk. This will drastically reduce the amount of volume you get out of your subs. May want to check that out.


Yeah, mine's like that. I've pretty much addressed it though. I will be putting insulation on the walls between the trunk and cabin to avoid resonance, and I will be removing the first aid kit box as it creates about a 10inx12in opening between the interior and trunk. I talked to a few guys on the Mercedes forums who had systems in the same body style and they said the first aid box makes for the perfect acoustic coupling chamber between the trunk and cabin. I'm not too worried about it.


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## SUX 2BU (Oct 27, 2008)

I built this system in my 1990 Daytona commuter car in 2003:









I competed IASCA SQ that year with it and hit 139 dB with an AC 3050 meter at a competition. That's an Alpine 6015CX run off 225W RMS from the one Concept CCA-752 amp. It was in about 2.8 cubes ported to 33 Hz.


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## 07azhhr (Dec 28, 2011)

haromaster87 said:


> Yeah, mine's like that. I've pretty much addressed it though. I will be putting insulation on the walls between the trunk and cabin to avoid resonance, and I will be removing the first aid kit box as it creates about a 10inx12in opening between the interior and trunk. I talked to a few guys on the Mercedes forums who had systems in the same body style and they said the first aid box makes for the perfect acoustic coupling chamber between the trunk and cabin. I'm not too worried about it.


 If you use a ported box and have the actual ports extend into this opening it will get your bass thru for you. I have seen this done in a 70's BMW 2002 (also has the tank behind the seat) and you could not even tell that there was only a small opening between the trunk and the cabin. Because of that car I did the same for a friends Lexus with great results. The ports fired thru the factory 10" sub opening. Sealed should work but firing ports directly into the cabin really helps.


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## haromaster87 (Jan 20, 2012)

07azhhr said:


> If you use a ported box and have the actual ports extend into this opening it will get your bass thru for you. I have seen this done in a 70's BMW 2002 (also has the tank behind the seat) and you could not even tell that there was only a small opening between the trunk and the cabin. Because of that car I did the same for a friends Lexus with great results. The ports fired thru the factory 10" sub opening. Sealed should work but firing ports directly into the cabin really helps.


Yeah I've read about people doing that. I've heard the main downside is you mainly hear the ports tuning freqency if you do it that way. I'm gonna be doing ported enclosures no mattery what. I'll probably just try out a normal set up at first and see how I like it and go from there. I'm probably going to go with a couple of prefab boxes at first and go from there. I know Pre-Fabs are generally not the most recommended thing to do, but I found a great deal on the RT Obcon boxes, which I can get a ported box that is apparently optimized for MTX subwoofers. I've read quite a few reviews, and for someone who is choosing to go with pre-fab, they're apparently a good choice.


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## haromaster87 (Jan 20, 2012)

SUX 2BU said:


> I built this system in my 1990 Daytona commuter car in 2003:
> 
> 
> 
> ...


That is a really slick looking set up btw. Beautiful craftsmanship. Very nice.


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## SUX 2BU (Oct 27, 2008)

Thank you  It was my first "big" install I did solely by myself. I did a few neat things with that install, it was just too bad there weren't enough local competitions at that time to show it off.


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## nubz69 (Aug 27, 2005)

Old school is great but I would ditch the Alpine head unit and get something current. Tape is dead for a good reason. A Sony CDX-GT660UP has more processing then you used to be able to find in a $600 head unit + processor back in the day. At a minimum you want time alignment and some flexible crossovers. 

I used to be able to hit 134.9 with 2X8" RF DVC subs and a soundSTORM amp i got for $25. The box I built was a dual folded horn enclosure. Take a look at the Wicked one sub enclosure on Audiophile Tube Amplifiers and Loudspeakers by DECWARE. I was in the mid 140s once I moved up to real 800wrms amp. This won't work for you but what will is to design and build a proper 4th order bandpass and port it through the opening you have available in your car.

If this is your interior.
http://cheapcarsdomain.com/wp-content/uploads/2011/04/mercedes-300d-interior.jpg
I would consider building out kick pods for some decent 5.25" or 6.25" with the tweeter in the kickpod, or I would build out the doors and put a good 6.25" or 8" driver in there. Having the midbasses that far behind you is going to throw things off. 

Build some old school FG kickpods and you will bring your car audio system to a level a lot of people have yet to ever hear.


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## haromaster87 (Jan 20, 2012)

nubz69 said:


> Old school is great but I would ditch the Alpine head unit and get something current. Tape is dead for a good reason. A Sony CDX-GT660UP has more processing then you used to be able to find in a $600 head unit + processor back in the day. At a minimum you want time alignment and some flexible crossovers.
> 
> I used to be able to hit 134.9 with 2X8" RF DVC subs and a soundSTORM amp i got for $25. The box I built was a dual folded horn enclosure. Take a look at the Wicked one sub enclosure on Audiophile Tube Amplifiers and Loudspeakers by DECWARE. I was in the mid 140s once I moved up to real 800wrms amp. This won't work for you but what will is to design and build a proper 4th order bandpass and port it through the opening you have available in your car.
> 
> ...



Hey man, thanks for all of the advice! I know a newer head unit might work better, but I already picked up an Alpine 7524 with the matching 5-disk changer. I know it's an old head unit, but I've read great things about the sound. I'll be wiring in an Aux cable, or using a Tape to aux cable adapter. But my actual music will be sourced from high bitrate MP3's on my Zune. I know that may not seem like the optimal source, but it will do fine for me.

That is a crazy looking box! I like it. As of right now, I ordered a couple of R/T Obcon ported subwoofer boxes. I got a great deal on them, and they are apparently a pretty decent solution to a pre-fabbed box. I do plan on doing a custom enclosure at some point, but it will take me a while to get the resources for that, so until then, I will enjoy these. I will have to keep that box you linked me up to in mind though.

And as for the Midbass, I realized how poor my idea was and I've decided to mount my 6.5 components in my door, and I have made adapter plates that will allow me to mount the tweeters in the far right and far left ac vents. It looks so cool. It aims the tweeters at the listener, it keeps them close to where the mids will and it looks awesome! This build is strange, I want it to have pretty good SQ, but it's not my main concern. Then I want it to be loud, but I don't expect it to be an SPL monster. Either way, I feel good that having the midbass right there will be so great for the sound.


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