Over Powering Speakers

[iz32]

I keep blowing subs with my current setup as i've always been advised its best to over power your speakers for a cleaner sound. understandably its a fine line between clean power and too much power.

now working with what i got, and sticking with the 300w rms range of subs to keep it near my splits volume capacity, is it better to overpower the sub with the gain backed off and match the amp/splits rms (like i have been) or vice versa?

equipment i use:

soundstream lil wonder 2x65 or 1x260 @ 4ohm

pioneer splits 60w rms.... i think?

jaycar response 2x150 or 1x500 @ 4ohm

subs ive killed:

pioneer 12" 150w rms

alpine type-s 12" 300w rms

im finding that with all the different bitrate music i download, my system can be fine for months with my gain tuned correctly for the lesser power sub, then suddenly some live recording with a low bitrate or poor recording sound, played loud, gives my amp a "what for" and pop goes the sub.

cheers in advance for any advise....

[GTR-32U]

a bit more info may be needed. How are the Subs boxed ? Sealed or ported ? Are they boxed at all or free air ? Different subs require different size enclosures ..

[Jack88]

sounds like your in need of a professional to tune your system mate,where abouts are you located?

Trying to match wattage ratings between speakers and subwoofers is usless. every speaker will have its own unique sensitivity rating.

for starters the range of subs you have tryed are very entry level units and obveiously not keeping up with your demands on them. as will any speaker or sub if you hear any hint of distortion or colouring of the sound that is not normally there turn it down!

i would suggest upgrading to the next model up from what you have tryed,so something like the TSW307D2.It will handel 400 WRMS and is a superior sub over all. I garentee you that this sub in the right enclosure will be more then enough for you. which brings me to my next question for you.

what enclosure have you been using your previous subs in? a small sealed enclosure about 50 or so liters im guesing as thats what most of them come with in the deals you get from most car audio places.

i have designed many systems using the older model TSW306C and the new model TWS307D2 and just about all of thos systems i have built the customer a ported enclosure tuned for the sub and the results have been more then enough volume and clarity with alot more head room and alot less stress on the sub over all alowing it to be pushed further if need be.

keep in mind that a sub enclosure can make or break the performance of the sub.

and finally the answer to your question, it is better to have more power on tap then not enough.pushing an amp too far and pushing it into cliping (distortion) will do far worse damage.

as with all music it will vary in volume and the volume of different instroments will vary so it is just something you need to be wary of,turn the volume down at the end of song before it changes to the next.

[iz32]

theres no fun in paying someone to do it

i have used a few box designs all up, the pioneer eventually blew in a generic ported box and lastly the type-s gave up in a small sealed box, near on a cubic foot which all round i felt sounded the best but seemed to plateau at very high volume.

in between the 2 above mentioned subs i used the TWS307D2 as bang for buck spec wise it looks a winner but after 3 enclosures i got rid of it cos i couldnt shake this mid-low bass emphasis it had which drowned out the sub bass. firstly i used a small sealed enclosure as per pioneers recommendations then a larger packed sealed enclosure and lastly a slot ported box i had made which is now a makeshift coffee table in the garage (internal measurements 300x350x350 + another 50x300x350 slot port) this gave me my sub bass but only at high volume and in hind sight i went a little too low on the tune for the box. there was hardly any bass response on low to moderate volume and it weighed a tonne. i've also listened to this sub in the prefabricated pioneer enclosure and didnt really like the sound, it was in a BA ute so that may have something to do with it.

i want to steer away from the 600+ price bracket for the next sub as its stepping into the next level of audio where my front stage cant keep up, which will end up snowballing and next thing i know ive got a system worth more then the car, been there before.

im no audiophile but like to know tricks of the trade...

so from what ive read the enclosure is the weak spot. i can stick with my current setup then pick a sub, get a custom box tuned for my application and go easy on the gain...im of the school of thought on letting the amps do the work as far as tuning goes and try to make minimal changes at the head unit only to adjust sound quality between different bitrates

[Vik]

Trust me, goto a professional.

I know that you want to learn, so go watch them install and tune it. Ask them questions, they're more than welcome to answer them..

I worked on my KH Laser's sound system myself.. loved it.

But now that i have the R34, i want everything done professionally so i wont be held liable if it screws up. Peice of mind, and you learn at the same time.

MRXTCZ

[Jack88]

The generic ported boxes are well, shyt lol.i have never herd any sub that sounds good in them.

The reason you killed the pioneer sub was probly because the enclosure was tuned so high and you were trying to get the sub to play lower then the tuning frequency which will cause the sub to unload and basicly just fry it.

by the sounds of things you have just had a bad experience with ported enclosures,i can garentee you that a well designed and built ported enclosure will destroy any sealed enclosure for clarity and over all volume.

also what you said about the ported enclosure not delivering the low end bass you wanted would be entirely down to bad tuning.what did you tune the one you built to? id work it out for you but you havnt given the length of the port as far as i can see just the port width.

you can pick up some excelent subs for between the 250 - 400 price range so keeping below the $600 figure shouldnt be a problem.

you shouldnt have any problem with a part of the system not being able to keep up with each other.its all down to the tuning,unless of course the system is really missmatched and there are huge differences in amplifier power.

"Trust me, goto a professional" this is why i was asking where about your located. your more then welcome to come watch me design and build an enclosure and ask as many questions as you want along the way to do with tuning and what not. there are a few people on this fourm that have had experience with my box designs and tuning setups that i have done for them so if you would like to hear from some people with first hand experience im sure they will chime in when they see this.

[iz32]

unfortunately im in wa but would appreciate it if you could help out with some numbers for an enclosure once i choose a sub... 60hz being the sweet spot.

btw....the slot port is 300 deep 300 high and 50 wide (giving it a 50mm gap at the back as the internal box depth is 350mm)

[Jack88]

Why were you trying to tune so high?

tuning to 60Hz in a box that size combined with the pioneer sub you tryed it with gives it a MASSIVE 7.1 dB spike at about 70Hz,that means the sub will be over twice as loud at these frequencys then any other in its range.

that would explaine your lack of bass. for starters its simply tuned way to high,for most dailys id tune around the 40Hz mark. a little spike in volume is ok and is to be expected in a ported box around the tuning frequecy but in my opinion the enclosure you built for the sub is far to small. i calculated it at about 1 cubic foot.

Im happy to help you with a design.just supply me with the T/S parameters of the sub you choose and the space you have to work with.

[Chris Rogers]

tune it at 45hz

-3db should be at 38hz and that will give plenty of decent low freq, set the subsonic at 20hz and cross it at 70-80 hz.

that should do it.

music taste - what is it?

[iz32]

id prefer the cross @ 60hz

gonna go with a type-r this time round but im a bit confused if i should stick with a sealed enclosure or go for a tuned port

DnB is the taste btw.

[philsGTR]

trust me tune to 33ish hz then itll play low, and it can still play highs

[Kinks]

so from what ive read the enclosure is the weak spot. i can stick with my current setup then pick a sub, get a custom box tuned for my application and go easy on the gain...im of the school of thought on letting the amps do the work as far as tuning goes and try to make minimal changes at the head unit only to adjust sound quality between different bitrates

You should be designing the sub + enclosure combination so that the natural frequency response is as close to ideal as possible. Generally this means aiming for a flat response before the "knee", a -3dB point of 40-50Hz and 12dB/octave rolloff.

After this, then set the amplifier level to match the rest of your system (bass/treble levels equal) and then tune the crossover point so the sub blends properly with your other speakers.

You should not be using the amplifier to band-aid a poor enclosure/speaker match by ramping up the gain. If your speaker is not matched to its enclosure and you try and correct it using the amp, then you will be pushing much more power at the speaker than you need to and it will fail.

some light reading for you:

http://www.bcae1.com/spboxad1.htm

[HEKT1K]

DnB is the taste btw.

well there's your problem don't get me wrong i love pendulum etc.. but it always feels like i'm punishing my sound system lol

Edited January 10, 2009 by HEKT1K

[Dose Pipe Sutututu]

Better to over power your sub, because the amp will provide a cleaner sine wave than it being underpowered and producing a square wave i.e. clipping which will toast voice coils

I recommend tuning it properly, that way you won't toast your equipment.

A good rule of thumb is to turn the gains to min. turn up the headunit as far as it can go before it starts to distort, then slowly turn up your gains will your sub is about to distort, once you've achieved that turn it down a tiny bit till it stops.

I've ran 1.5kWs into a a solobaric and it didn't die, I did the same to 2x Boston Pro LFs same deal, if you tune your shiet properly it won't die.

Also enabling your subsonic filter will help prolong the life of your sub, this stops the sub from bottoming out, sometimes shiet downloaded crap will have real low notes in them, which equals sub death. setting your sub sonic to llike 15hz and your LPF to around 80hz would be ideal, some like it around 60hz or 70hz and have the front stage set at like 60hz to enhance more mid bass staging.

each to their own.

that's my 2.5cents LOL

[Stagea_Neo]

Definitely get the box tuned, port length, box volume, vented/sealed etc...

It makes a world of difference.

I've seen/heard a Jaycar 10" sub with whatever response (blue) amp, approximately $400 total outlay,

done at home in a properly calculated & constructed box totally kick ar$% over a Kicker 15" sub and PPI

amp setup which was apparently setup/boxed by professionals at a cost of just over a $1000.

Also those songs you are downloading.....the person who originally copied them may not have normalized

the volume of the songs, or the software used my have also boosted/clipped frequencies and you will find big variances in overall volume and also with particular frequencies.

I could have AC/DC or Metallica pumping at full tilt S*!tload of bass and crystal clear then i may switch to a rap or techno genre song then the bass will distort the speakers because the person who ripped the song did so at %100 normalized setting and accidentally left the parametric equalizer set with bass boost.

You may need to go through the tedious process of normalising your mp3 collection so all the songs have the same volume.

-have a read of this, it mentions audiograbber, handy little program.

http://www.cnet.com.au/mp3players/musicsof...40057551,00.htm

[SoarerGT-T Cruiser]

i know for a fact that the alpine type S alpine subs are dual voice coil. The jaycar amp you have is a 2 channel. when you bridge 2 channels in an amplifier, you effectively half the resistance. normally in single channel mode you can run a 4 ohm speaker at 4 ohms, and a 2 ohm speaker at 2 ohms. bridging the amp will change this. as a result the least resistance you can run on a bridged amplifier (unless specified) is 4 ohms. as this will run the amp in 2 ohm mode.

I am supprised that you didn't kill the amplifier with the alpine sub as the system would have been running in 1 ohm, probably giving an effective power output of anywhere between 800 and 1000w rms. and the amp would have been able to cook bacon and eggs .

depending on how you want to go, you could run 2 dual voice coil subs (one of each channel) in 2 ohm mode, which will give 500 wrms or (starting to get more technical now) run each woofer in 2 ohm (voice coils in paralell) and then run both woofers in series (this will give an effective resistance of 4 ohms) meaning that you will get your 500w and probably not do any damage.

However as everyone has said before, more power is better than less, but too much is just as bad as not enough. if that makes sense.

just to remember, when working with equal resistances i.e. 4 ohm and 4 ohm, in series + > - > + > - it will give a resistance of 8 ohms so just add the 2 voice coil impedecnes together. when in parallell + > + and - > - it will give 2 ohms, just divide the impedences by 2

hope this helps

[-FIGJAM-]

so much to take into consideration, thats why i am saving my cash and going to take my baby to the shop and say i have this much lets talk... easier and hassle free.

Good luck with it tho, word of advice listen to Chris and Jack, they know their stuff...