Going crazy with RL-s 15's

**01-21-07, 01:20 AM**

Ok so im looking to blow my house apart, I've been learning about building my own speakers for over 6 months now so I know what im doing with this even though im only 15, anyways, the RL-s 15 has always caught my eye although it is twice as much as the RL-p 15 which is what i should be looking at Im a guy that only wants the best of the best, I've seen the Soundstream XXX-15 and i think they even put out an XXX-18

but theres just too much money involved there, anyways, I am for now going to purchase 4 Mach 5 Audio MJ-18 which arent nothin too shiny bout that average for an 18 but for around 65 a peice they are a steal and i am planning to make a cabinet for each one and have one in each corner for now, my room isnt huge at all but I want bass that will completely ingulf me and anything else unlucky enough too be in the room at the time so dont question my choices cause i am a little bit

lol but i know when loud enough is lud enough and all that so dont worry anways, after I get them up and running I was looking at doing something with multiple 's Rl-s 15 when i get the money saved up again and so who has any suggestions? I am NOT one for any childs play i want the real deal so dont try to talk me out of this cause i want the meat to be rattling off my bones at when the dial isnt even 1/4 the way up. I was thinking of doin an infintie baffle but ill eventually be moving so that out of the question but i want some thing mean that willl make people a mile away think a bomb is going off

**Sonnie** · **01-21-07, 01:41 AM**

Hi Josh and welcome to the Shack!

We can probably point you in the right direction, but remember that what you are wanting is going to have a huge impact on not just your room, but the entire home. Make sure your parents are not going to mind, because they are definitely going to know about it when you are done.

I'm moving your thread to DIY.

**warnerwh** · **01-22-07, 12:06 AM**

Oh, I don't think his parents will notice.

A young man wanting to design and construct his own subs I personally would encourage. I'm glad we have a girl. Although she is bass happy with her system and I'm going to have to get some resistors or something if you know what I mean..

In seriousness though I'd definitely let your parents know your intentions. Be sure to tell them that your subs will be vibrating the entire house. If you have a big, and I mean big, house and your on the other side or a couple of stories apart you will be fine.

Best of luck with your project. Be sure to post pics as you go.

**kano32** · **01-22-07, 12:33 AM**

Howdy,

Are these just for music or will they be used for HT?

**kano32** · **01-22-07, 12:43 AM**

You could build each box about 3.2 cu ft tuned to 28Hz feeding each about 500watts. Or about 5 cu ft each box tuned to 27Hz with 500 watts. Four of these things would put out enough sound in a bedroom to make you deaf. But I guess that's want you're looking for.

**01-22-07, 06:03 PM**

ummm im thinking something like 65% music 35% HT, and I've ran simulations on the MJ-18 and i might as well be throwing stones at a wall cause they dont shine without at least 8ft^3 ported @ 34 Hz ( i would like to have them go lower but these dont have it in em to go any lower so I'm just gonna go for SPL for now) and they'll be running about 600 watts rms each powered by an europower 2500 bridged running two pairs wired in parallel wired in series , thanx for the support I've been posting a DIY audio and they were very helpful still not as enthusiastic about my wild plans as you guys are. I've have clearly stated to my dad what I am planning to do and i dont quite think he gets it yet cause every time he goes o best buy he's always complains about the little dual 12's or dual 10's they'll have running and i look at him crossed eyed and tell him that those are child's play compared to what im doing. But i think in his head this is all going in the living room b/c i already have my system in their b/c the comp is in my room but when we move in the next few months Im getting my system back which isnt much (little $200 bookshelf system with a 5" sub and im also running two Pioneer's with 15" woofers that are so old you can't even find them online except for spare parts lol and i'm almost ashamed of myself with my lil 5" sub right now so I plan to make a major overhual with this and then when i get a job within the next 8 months my HT plans will really start speeding up then

**warnerwh** · **01-22-07, 08:42 PM**

I'd think you can get what you need done with one RL-P 15. You can get the lows and the quality with one of these at a similar price to the four 18's. Plus the cost of only one cabinet compared to what you'd need for four 18" drivers will probably save money in the end. This way if you want to upgrade to more output power you can do another RL-P 15 sub or even go with two like I just did for a friend.

Just one of the SS drivers is an excellent performer and should keep you satisfied for at least a while I would hope.

It's better to spend your money on something you will want to keep down the road. The four 18's aren't of the best quality and you'll end up selling them at a loss and will end up losing more money. Listen to the older guys, we're trying to help.

**01-23-07, 05:18 PM**

i know and I'm thinking about that too but it''s plain math that 4 18's even with a weak 12 mm Xmax move more air than a high performance 15 , don't get me wrong I love The RL-P 15" but right now what I'm looking for is SPL in the 30Hz and above range also b/c these subs will double as the bass extension for my bass playing and my bass down tuned to E on heavy gauge strings only goes down to 37Hz so I'm compromising betwen SPL,lower extension and cost at the moment.

**Exocer** · **01-23-07, 06:05 PM**

punkrokr1701, you're after some insane Spl aren't ya?

How large of an enclosure can you accommodate in your listening room?
Would you prefer ported or sealed subs?

**01-23-07, 07:00 PM**

Well by the time i get the money to start the RL-s 15's my room will be around 15'*20' / 300 sq ft at the minimum, I'm gonna shoot to go for 17'*22' / 374 sq ft b/c we're moving soon a and when we do my room is gonna be an addition so I kinda have an advantage b/c i can also pad my room down and take some measures to isolate sound so that it doesn't completely destroying the rest of the house

anyways, I prefer ported all the way and since I'll have the 4 MJ-18's done up in each corner by then I'm gonna want some infra sonic capabilities from the RL-s 15's but IB is out of the question for now until i can talk it over with dad cause i still don't think he completely gets just how loud this is gonna be even though I talked to him and told him straight up what my intentions are, enclosure size? ha like I always say bigger is better

**warnerwh** · **01-23-07, 07:51 PM**

Get back to me when you do the room addition. If you're smart you can isolate the sound very well for not all that much more money. Being as it will be new it will be easy to do too.

I understand now what you're trying to do. I didn't realize you played the bass and must have missed it somehow.

**JorgenMan** · **01-24-07, 06:21 PM**

Just so I'm sure I understand correctly, you're doing four MJ-18s now, and then RL-s 15"s later? You won't want to have the MJ-18s and the RL-s 15"s running at the same time - you'll be better off with one or the other. Forgive me if you already knew this, but I'd hate to see you make plans without knowing.
How soon do you plan on buying the RL-ses? If it won't be too long, I'd say just wait and do it right to begin with.

You should also check out the Q18 at ficaraudio.com - it's a lot of displacement for the money.

**Exocer** · **01-24-07, 06:27 PM**

Quote:

JorgenMan wrote:

Just so I'm sure I understand correctly, you're doing four MJ-18s now, and then RL-s 15"s later? You won't want to have the MJ-18s and the RL-s 15"s running at the same time - you'll be better off with one or the other. Forgive me if you already knew this, but I'd hate to see you make plans without knowing.
How soon do you plan on buying the RL-ses? If it won't be too long, I'd say just wait and do it right to begin with.

You should also check out the Q18 at ficaraudio.com - it's a lot of displacement for the money.

Good post, I totally agree...and wish someone were around to tell me I should've done things right the first time around...I would be a richer person now, thats for sure

FYI, scott at ficaraudio can customize drivers depending on your needs.

**Chrisbee** · **01-25-07, 09:01 AM**

Deliberately making yourself deaf is one of the dumbest ideas I've heard in a long while!

Think of all those years missing birdsong.

Or the soft whisper of your girlfriend.

The only teens worth listening to at high SPLs are measured in Hz!

Aim for quality, quality and more quality.

Aim low in Hz and even lower in distortion.

SPLs are completely meaningless once you're much over 110 dB peak @ 20Hz and higher.

15Hz at well above 100dB will terrify you and needs only a single 15" driver and a Sonotube for that small footprint.

A Sonosub can be carried at a fast run when you get thrown out by the neighborhood lynch mob far easier than those 4 x giant 18" white elephants.

The boxes you will be forced to leave behind just to save your miserable, deaf bod!

A Sonosub? It has that real wow factor with knobs on. It's a chap thing!

Hope this helps?

**warnerwh** · **01-25-07, 12:13 PM**

The post above brings up an excellent point. At your age it's easy to think you're invincible. We're here to let you know what you plan is probably a very bad idea. You will pay for it in a way that is difficult to understand until you start losing your hearing. It won't happen in one day but after a year or two you'll wished you'd listened.

A single SS 15" will output plenty of what you want. To be honest and blunt it's not very bright to listen to volumes over 100db for any period of time. I'm not guessing as I have tinnitus and wished I'd listened but when you're young you don't understand. It would be nice to see a young person be smart and listen instead of learning the hard way as many of us have.

**SteveCallas** · **01-25-07, 01:16 PM**

I agree in the sense that most starting off don't have a good frame of reference for what 110db-120db bass capability really is. If you already have your speakers and a receiver (and hopefully an spl meter), calibrate your speakers to reference level. Now put in a dvd and listen at reference level - unless you have hearing damage, you'll quickly realize that it is extremely loud. That correlates to 115-120db subwoofer capability.

If you try that and still decide you want to build more headroom onto more headroom above 30hz - as opposed to say 110-115db headroom down to the low teens, more power to you, and the Mach 18 is a good choice. Honestly though, when you experience powerful infrasonics in a movie for the first time, you'll never go back

But for your stated goal, for each driver, I'd go 250 liters with an 8" port that is 12" long fed with the PE 500 watt plate amp (on sale now) and a 20hz highpass. Even if you wanted to throw a house party, two such subs would be more than enough, 124db+ levels from 30hz on up. Save your money on the other two drivers to put towards a system that goes much lower in the future.

**SteveCallas** · **01-25-07, 01:35 PM**

And actually, if you have the space, you could shift some sensitivity down low and end up with a more accurate sub. 400 liters, 8" port that is 14" long, 500 watts, 16hz high pass. 115db+ from 22hz on up with one. Build two, and now you've got an extremely capable system on your hands. 400 liters a piece is pretty large though if you don't know what you're geting yourself into. Think the size of a medium desk.

**Chrisbee** · **01-25-07, 01:52 PM**

http://www.ccohs.ca/oshanswers/phys_...osure_can.html

http://www.cdc.gov/nasd/docs/d000801...2/d000882.html

Note the allowed exposure times against dB:

When you find you can longer hear ordinary conversation against any background noise you will wish you had listened to us instead of Steve. It seems that neither of you are mature enough to make this decision or you would not be designing something which provides these insane levels in the first place.

I do not believe anybody here should be encouraging you to build something which is guaranteed to damage your hearing in a relatively short period of exposure.

Notwithstanding the reduced risk from lower frequencies the wisest souls will always council LF extension over increased SPLs. The danger is always that you will try to emulate the performance of your subwoofers with speakers to match.

A real subwoofer is measured not by what it can do over 30Hz but what it can do below it.

Give me 0.5 extra dB below 20Hz before you give me 10dB extra above it!

Pardon?

**SteveCallas** · **01-25-07, 02:21 PM**

Quote:

When you find you can longer hear ordinary conversation against any background noise you will wish you had listened to us instead of Steve. It seems that neither of you are mature enough to make this decision or you would not be designing something which provides these insane levels in the first place.

I do not believe anybody here should be encouraging you to build something which is guaranteed to damage your hearing in a relatively short period of exposure.

I had to do a double take here - are you being serious?

First off, just because a system is capable of 124db+ levels doesn't mean it will be played at 124db+ levels. That should be obvious. He believes he wants insane levels, but once he has the finished sub in his hands, he'll see that even spirirted listening levels are much lower. Headroom is a good thing in the sense that distortion is minimized - I think he'd prefer more extension, but to each his own.

Second, no offense intended, but your own sub isn't exactly a bottom troller. It's natural response isn't too far from what punk seems to be wanting to build, and I'm sure you are capable of 124db+ levels above 30hz. Is THAT responsible? Of course it is, because anyone intelligent enough to build a sub would know when they are playing "too loud".

What you are arguing here is akin to blaming car manufacturers for building devices that could potentially be used to kill people. Or maybe a lighter manufacturers for building devices that could potentially be used to start fires. Come on, let's get real

**Chrisbee** · **01-25-07, 02:53 PM**

I disagree. The OP mentions "crazy" in his thread title. He wants LOUD!

Do you really think that he won't be cranking the gain at every opportunity?

Or were you thinking these boxes would all be carefully calibrated with the speakers to give low distortion and high headroom?

You show the same excitement for dB racing in many of your posts spread across the AV forums.

What has intelligence to do with extreme SPLs and youthful enthusiasm?

My IB seems to be suffering from AE's now-infamous non-spec Fs. This may well explain why AE are no longer trading.

Given your internationally renowned skills at subwoofer design you may like to work out my expected IB response curve given a true 16Hz Fs in 16 cu meters? Should I really require a +16dB boost @ 20Hz using 4 x 15" and still fail miserably in matching a budget SVS 16-46PCI?

**SteveCallas** · **01-25-07, 04:04 PM**

Quote:

I disagree. The OP mentions "crazy" in his thread title. He wants LOUD!

Do you really think that he won't be cranking the gain at every opportunity?

Or were you thinking these boxes would all be carefully calibrated with the speakers to give low distortion and high headroom?

, I'm not gonna judge the guy. Ok, maybe his grammar was a bit poor

but I don't have any reason to assume he would lack enough intelligence to intentionally cause himself hearing damage. Give him some credit. And he still lives with his parents after all - they will have to experience what he is.

Quote:

you may like to work out my expected IB response curve given a true 16Hz Fs in 16 cu meters? Should I really require a +16dB boost @ 20Hz using 4 x 15" and still fail miserably in matching a budget SVS 16-46PCI?

My statement had nothing to do with your design - I don't doubt you weren't aiming for that response - it was simply used to show that what you have naturally is similar to what punk wants, and that it doesn't guarantee irresponsible listening levels, far from it.

Quote:

The OP mentions "crazy" in his thread title. He wants LOUD!

Let's go ahead and assume a worst case scenario. He unwisely cranks this thing and listens at 120db+ levels for extended periods of time, eventually causing himself hearing damage. He's responsible for his own actions, it's evolution at work my friend.

**Chrisbee** · **01-25-07, 04:14 PM**

It's odd how I never had any respect whatsoever for those who waste their entire lives on weapons design for "a safer world".

Whats your trivial excuse?

http://www.darwinawards.com/

**SteveCallas** · **01-25-07, 04:34 PM**

I like this place too much to keep this going (it's not AVS after all

). You win my friend.

**Chrisbee** · **01-25-07, 04:41 PM**

Well, at least I didn't call him "a punk".

**warnerwh** · **01-25-07, 07:14 PM**

You guys need to remember this guy is 15. When I was that age I thought I was bullet proof. Odds are high that he would be doing damage to his hearing. Also the fact he'd like some quality subs in the future suggested to me to start with the better driver now. This kills two birds with one stone.

I have to agree with Steve regarding subs that are over kill. This keeps distortion down. My car will go 160 but I've never taken it that fast. The advantage of having a car that is stable at 160 means at 70 it's very very stable. Same difference.

The ported sub using dual SS RL-P 15's I built for a friend are going in a 18x25 living room. One driver would have been enough. My goal however had been to build an excellent quality sub for him. Two drivers will have significantly less distortion.
Ok, I'm done now.

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