Using a sine wav to break in a sub...

ASSISTANCE Electrical & Entertainment Systems
1

I’ve heard that you should play your sub fairly quietly for a couple weeks to break it in. That kinda sucks since after waiting all the time to get th system set up, I don’t wanna wait two weeks to crank it up.

So I was looking around, and found a SPL speaker review, there they said they broke the sub in using a 20hz Sine Wave for 4 hours. I found a sine wav that was 350hz-20hz.

I’ve edited in to a couple approximate Hz ranges, let me know which you guys would thnk would be the best to break in a new sub, I don’t know if 20hz is too low for a Shiva 12".

Here they are:

http://www.shawnblais.com/35_to_20_sine_sweep.mp3
http://www.shawnblais.com/50_to_30_sine_sweep.mp3

2

I found a program that can generate any Hz frequency I want, so I can make a steady 20hz.

No one has any input on this subject?

3

Yep, break in periods are key. You don’t floor your brand new car, why over-exert your sub before it is fully capable of handling it?

I have heard of the breaking-in method using a Sine wave (mostly through magazines testing). Since I don’t know what your sub is crossed over at, or what it is tuned to, best thing to do is to contact Shiva themselves and ask them. Also, ask them how strong a signal you should feed through the sub (how many watts while playing the Sine wave).

HTH-

Amrit

4

Well I’ll be tuned to the low 30’s, and I don’t know what my subs’ll be crossed over at. but I’ll be running 2 6 1/2’s up front and a 12" shiva in the back.

I’ll email adire and see what they have to say,
thx

SHawn

5

bleh im sure thats geared towards high spl subs. ive never seen anyone compare a broken-in sub vs a non-broken-in sub with sub-500rms drivers. but with that in mind, i guess just dont test its xmax within the first few days or 20hours of play or so to be safe.

6

Adire’s reply:

Shawn,

Thanks for the e-mail! Best way to break it in is to play it. Start at low
volumes to make sure the install is solid - no loose wires, connections, box
leaks, etc. Increase the volume over a day or two and you’re set.

Drivers break in quite quickly; what you want to be careful of is that the
install is still solid. Any time you add or change out any component in
your system, it’s best to take a day or two at low levels to make sure
everything is rock-solid before running it wide open.

Thanks again,

Adire Tech Support

7

purely for daily driving, but I said low 30’s like 33hz

8

Originally posted by gen2ls/vtec
[B]
My concern is you wanting to tune your sub to 30hz- that is barely audible and most music is not going to produce any notes that low. Is this setup strictly for DB competition or do oyu plan on enjoying it :shrug:

:bow: [/B]

The higher the tuning (i.e. 50 hz), the more spl (or DB as you said)oriented the box is. That means it’s louder, but doesn’t reproduce music as well(sounds like crap). Tuning to 30hz will allow the music to go that low plus 2 or 3 hz lower and not be so peaky, wich in turn makes the sub blend better, wich in turn has better SQ or “sound quality” (how good it sounds and how well it reproduces music).

The tuning of a ported box allows you to control the sub more. If he tunes it too 30hz, and has it crossed over at 80hz, the sub will play notes from 30-80 hz give or take a few hz. Go download winisd at www.lineareteam.org (I think that’s how you spell it), put your driver’s specs in and look at the spl slope. Look at the default ported box. It will most likelly be a huge box tuned to the low to mid 20’s. and have a perfectlly flat slope ( the green line on those charts). Now change the tuning to 60 hz and look at the slope. See how it peaks way the hell up at 50-70 hz? That means that the bass will sound groselly exaggertaed and just be making loud noise, not reproducing music wich is what a sub is supposed to do. That basically means that it will sound like crap.

The most desired slope is a nice flat curve, not one that’s peaky. A small peak in the 30-50 hz region is fine for a daily driver and will still sound great. That actually is desired because it will make the sub louder, while not exagerating the sound it’s trying to reproduce too much. The lower the tuning (to a certain extent), the flatter the curve. A really peaky box will not reproduce music as well because the bass notes are groselly exagerated, distorted, louder, and more unrealistic on the notes that peak.

The shivas has an extremelly low fs, so you could throw the shiva in a big ass ported box tuned to 25 hz, and it will get extremelly low and loud while sounding great. Most quality subs are capable of going down to 20 hz.

Now as far as the sine wave, that isn’t neede for that sub. Just take it easy for a week or so listening to low volumes, and only crank it up for a few seconds at a time when you get the urge.

I apoligise for the lenghty post. I’m really becoming a post whore. I get a :whore: hehe

9

I’ll change that link later tonight or tommorw after I find out how to spell it.:rocket:

10

I didn’t say the flattest slope possible was the best or what he wanted. I said that a small peak was good and desirable and that he can acheive that happy medium with a ported box tuned to 30hz. Great SQ and output. Hell, 30 hz is pretty SQ geared. You’re not going to see anyone winning any DB drags with a box tuned to 30 hz. More like 45-65 hz depending many factors.

Sealed boxes can be very peaky as well depending on the size. It’ very possible for a ported box to have a flatter slope and better SQ than a sealed box. I didn’t really say anything about the comparison of ported to sealed though. I was simply talking about tuning of a ported box because you implied that tuning to 30 hz would not be enjoyable and asked if he was only going to be DB competing with it. That leads me to belive that you think 30 hz is an SPL tuning and it won’t sound good, when it is in fact very far from it. I’m definatelly not saying that you think that, I’m just saying that is what that statement lead me to belive.:slight_smile:

30 hz is VERY audible and tuning to 30’s is more SQ oriented than SPL oriented. A 30 hz note is just as audible as a 60 hz note. The 30 hz is just lower. The human ear can hear well into the low 20 to high teen regions depending on the person. The lower you tune, the more SQ geared it is, the higher you tune, the more SPL geared it is.

Soo, are you saying the higher the tuning, the better the SQ? Why wouldn’t his sub sound good in a ported enclosure tuned to 30hz? Why would he only be competing with that box and not enjoy it for a daily driver? I’m surelly not saying that you said or think any of that, that’s just what I got out of what you said :up:. I’m a little confused as to what you’re saying bro. Please enlighten :bow:

11

What do you mean by cycles? I’m not farmilar with that term. Do you mean hertz? Maybe we’re talking about two different meausres of notes, lol. Are you from a diferent country?

I’ve never heard of a company telling you to tune to 50 HZ. Most tell you to tune to 30hz or 35hz for a daily driver. I can give you a loooong list of companieswebsites that tell you to tune in that region and don’t know of a single company that would tell you to tune your box to 50hz for daily driving. If scooby emailed adire and asked them what the optimum tuning for the shiva. I’m sure they would say something along the lines of 25-30hz. If the said 50hz or anything above 35-40 hz for that matter, I’d mess myself. Please give me a list of companies websites that reccomend tuning to 50hz. :crazy: hehe j/k

I agree with you, that most music doesn’t have 30 hz notes in it. But the reason for tuning that low is not to hear 30 hz notes, it’s to prevent the box from being peaky and have a flatter slope than say… a box tuned to 40 hz.

If you were to tune to 50 hz, the sub wouldn’t get any where near a 30hz note, maybe a 45 hz note, but nothing lower.

How are you tuning a sealed box, lol? Theres no port to tune?

Yah, most younger kids just want loud bass and not a complete system (i.e. no mids and highs, just lows). Though I do compete in SPL, I love SQ too and am still a young 19. I guess I’m gettin old, hehe. I can’t speak for scooby, but from talking with him before, I got the impression that he just doesn’t want loud noise. He wants a sub to sound good. Tuning anywhere above 40hz for any sub, let alone a shiva that has an extremelly low fs, WILL not have good SQ. Not flaming you at all, just stating mine, and 99% of other car audio enthusiasts opinions :up:

You never really answered my previous questions. Why wouldn’t his sub sound good in a ported box tuned to 30hz? What do you suggest he tunes his box too? Why would he only be competing in DB drags and have it not be enjoyable if his box were to be tuned to 30hz? I’m still not understanding what you’re reffering too bro. Man… our posts have become pretty off topic, but oh well :wink:

Good talking with you man and I look forward to your responses. On a side note, I’m glad to see you stuck with the G2 after all of what happened. You’re car is awesome and congrats on getting her running again. I’m sure you’re a happy man:bow: PEACE!!!

12

hertz=cycles per second

maybe hes referring to xover or center frequency at 50hz. i change mine from 45-80 on my parametric eq depending on the song. ya usually boxes are tuned at 20-30’s

13

here’s the winISD plots. a box tuned to 50hz has higher SPL and Gain values. on my guitar amp, gain is distortion, same here?

And no I don’t want the bass to overwhelm the music, i hate that sh1t,

14

Yah scooby, that’s exactlly what I was reffereing too. See how it peaks way up? That means that any notes in the peak region will be a lot louder than any other notes. So it’s not accuratelly reproducing the notes. It just exaggerates them in the peak region, and doesn’t emphasise the notes enough in the non peak region. Tuning to 50hz in a daily driver is absolutelly unheard of because it will just be loud noise, not really music. And the reason you have bass in a daily driver is too enhance music, not just add loud noise. For SPL competeion, all you want is noise, not music. Ever heard of a one note wonder? That is exactlly what you get when you tune high like that and that’s what people are reffering too. It’s just loud in the peak and sounds like it’s just one note. You can’t hear a range of music, it’s just one noise.

15

I emailed adire and told them the size of my box, here’s what he said:

In that large of a box, I’d look at around 24-25 Hz.
Should give a much better sound quality and still very good SPL. I’d also
look to run around 250-300W of power; more power isn’t really needed, since
300W will get full output from the Shiva in that large of a cabinet.

16

Yah, you can try it out at 25 hz first. Than just keep cutting the ports untill it sounds good. Dan isn’t too much of an spl fan, he has a brahama in his vehicle with only 2 or 300 watts to it and it’s rated at 1600 :sad:. So he’s pretty much just a fan of SQ and could care less how loud it is. It’ll probablly sound good to you for a couple of days, but then you’ll want more output. I had my shiva tuned to 34hz and it sounded perfect. So I say 31-34 hz and you will LOVE it and never have to change it. Plus it’s a painin the ass to pull out round ports and cut them. So have you got started on your box yet? Did you order your stuff? What all did you get? I’m curious.

17

Ya Man, the box is built. I posted a pic in my other thread,

minus the sub displacement, and braces, i get 2.54 cubic feet. we made the false back and bottom and it works sweet. The back is totally flush woth the trunk sides and is gonna look real clean when it’s carpeted. and my spare tire is still fully functional. I’ll have more pics when it’s done.

here’s my wishlist, the sub isn’t on there,

I’ll be ordering all my stuff when I can get the cash together, stay tuned! :cool:

18

Nice!!! lokking good man. If you ordered some of that stuff on ebay, you’d save some money. Also, stay away from those schoche install kits, they suck ass. Get an American International at best buy or circuit city, they are pretty sturdy. Scoche’s are the weak and flimsy and usually don’t fit right. Sounddomain usually take a hella long time to ship your order too. Anyway, everything looks good and I forsee you becoming giddy as a school girl when you first listen to everything. Keep us posted :up:

19

ya I’ve been looking at Ebay, there’s not alot on there it seems, and I’m not the patient type to wait around until something shows up. that being said, i probably would buy off Ebay if I had my own credit card, but right now I have to borrow a friends card and just slap them the cash, so I think it’s just easier if I order it at a set price from a store.

The cool thing about ordering all the stuff from the same place is the shipping isn’t too expensive, it seems the minimum shipping to canada is usually around $25 and for all that stuff it’s only $60.

There’s no best-buys or circuit city’s around here but I’ll look around town for the American International install kits, do you know any good places that sell them online?

edit-- am I missing anything on my list? those stinger kits r OK? I need 2 right?

20

Originally posted by gen2ls/vtec
[B]When I meant “tune” a sealed sub I simply meant making the box larger or smaller depending on the power that is available to the sub and the preferences of the customer. And 1 cycle is 1 HZ.

on everything else, I guess its a difference in experience. I have had better luck getting a flat or close to flat EQ when tuning a ported sub higher than 30 cycles.

:bow: [/B]

What;s up ls/vtec. Yah, that is what I thought you meant about the sealed, that’s just a weird way of saying it.

A different experience? Can you please explain my questions to you specifically? I’m really interested to hear your explanations on them. Can you explain how you get a flatter slope by tuning a port to 50 hz than tuning a port to 30hz? It’s physically imposible too and there just isn’t a way to do it. We should make a post on www.termpro.com that is just like this and see what all of the car audio experst say about your theory of the higher you tune, the better SQ you get (i.e. a flatter slope). Just look at the chart that scooby posted, that proves it right now. Please don’t give me a universal answer, I’d really like specific answers to my specific questions on my earlier posts and this post or an admitance to you being wrong and not really know what you’re talking about. Sorry if that sounds like I’m being a dick, didn’t mean it in that way. No flame intended brother. I respect you and your opinoins :bow: <—we really got this bow thing going on don’t we :cool: