Buying some 8w7v2's used, need advice...

[Kraayl]

Im buying 2 subs and i want to know if there is anyway someone could hide damage to them? I dont think they are gonna be hooked up and he claims they are out of box new, so i just want to know if there is anything i should watch out for?

[PoorManQ45]

It's very easy to hide the damage, because you can't see it in the first place!

The most common failure on a driver is the VC breaks from too much power, suspension is worn due to over excursion.

The common, but more obvious damage is to the cone itself. It gets punctured by random objects, same thing for the surround. Both of these things can be repaired though.

[zerepdivad]

Im buying 2 subs and i want to know if there is anyway someone could hide damage to them? I dont think they are gonna be hooked up and he claims they are out of box new, so i just want to know if there is anything i should watch out for?

this may seem weird but smell the magnet and if you smell a kind of burnt plasticish smell they're probably either not working or won't work much longer.

[Kraayl]

Im making the guy show me they work. He is charging me over regular street price and its starting to sound shady, so he either shows me in person or im going to walk. He is now trying to get the 2 subs and 2 matching amps off on me. Any advice on price for all that?

[PoorManQ45]

I recommend that you just don't go through with that deal.

I'm pretty sure, but I'll ask anyways, are you more interested in SPL or SQ?

If it's SQ(with very good SPL) then I would recommend you look at partsexpress.com . specifically at the Dayton 15" MkII. Give it 8ft^3 tuned to 19hz(use two ports) and you'll be able to hit 120dB+ at 20hz. If you plug one of the ports it'll change the tuning to 13hz. You'll be able to hit 115dB @13hz.

Those numbers may not sound significant, but you have to realize that 13hz is approaching earthquake levels. And the best thing is that the SQ will be better then anything you've ever heard.

Driver will cost $175.

Now, you won't have the loudest system on the block, but I can guarantee you that you'll have the lowest(frequency) playing system, and probably the best sounding system(at least in the bass range)

[Kraayl]

I semi understand what your saying. Im trying to read up on everything so i can get my system to knock right. I ended up gettin the 2 8's they worked and he wanted 500, somehow i got him to 250, but he wouldnt sell me the amps for less that 400...I dont think i could fit a 15 inch sub in my car, i got a 240sx 90'...any advice on where to get general info on how to set up a system?

[PoorManQ45]

Just ask questions.

You could get a 15in driver in there. The problem isn't that, it's the 8ft^3 that it needs

[Kraayl]

Well here we go, the recommended rms for those subs is 250w but a lot of my friends say that since its a w7 i could push 500 through 1 of them. I really dont want to ruin them though. Bad or good idea?

[PoorManQ45]

Bad idea. Going from 250w to 500w is only a 3dB increase. It is noticeable, but not worth the risk.

I'd say no more then 300w.

[starkos14]

and btw, no such thing as 8w7v2 its only 8w7 no v2.... yet

[Shade240sx]

You can use a 1200watts amp on a 8"w7.

You be amaze what this sub can handle. I got 2 10in w0, with a 1200watts MA audio amp. If a w0 can handle a 1200wattz amp. A w7 can also handle 1200watts amp.
Modified by Shade240sx at 3:10 AM 3/27/2006

[PoorManQ45]

Ok, with that great grammer I think I got what you're trying to say.

Ok, something you guys need to understand is that just because your amplifier can put out 800w RMS, that doesn't mean that it's going to be doing that all the time. For day to day listening you're probably around 100~300wRMS maximum. When you're trying to impress someone(BTW that is stupid) and you turn the volume up above 75%~90% you *might* get the amplifier to put out its rated RMS power. It depends on how the gain is set.

If it's set properly you should be able to turn th evolume to 100% without the amplifier itself clipping. I wouldn't recommend doing this though as the PRe-Outs on the HU will clip and cause harm also(not as much as amp clipping though)

Anyways, I'd like to see one of you guys put an ampmeter on your setup. Then I'd like you to have someone take a picture of your face at the exact moment that you see that you're using way less power then you think you are.

[Silvia2b]

O.k. but how is most damage to speakers caused? With too little power supplying the amplification, that's how. More clean power = less of a possiblity causing speaker damage, but also still not operating at the full rated amplifier power 100% of the time as PMQ mentioned. This assumes the obvious that a quailfied individual or entity conducts the setup.

[240z4u]

I am actually shocked at what PoorManQ45 said!! I am appauled at the fact that he would supply correct, and valuable information on a car audio forum!! LOL

Anyway, Having installed a pair of 8w7s they are okay... For the money you got them for they are alright though. Those things weigh a freaking ton. And you do NOT need more than 500 watts for the pair, the set I installed was with a JL 500.1 and it was plenty of power.

PoorMan/Silvia is right though, a 1500 watt RMS amp is only 1500 watts if you can supply the current to make it hit full power (and most of what I see, there is no way its going to happen in most peoples cars). But on the other hand, absolutely do NOT underpower those subs. Distortion kills woofers much quicker than power does in most situations.

JL W7s are designed to impress freinds and wail on SPL mic's, not impress sound quality judges LOL.

I usually do not chime in on the forums, but I had specific experience here so I thought I would share.

Evan

[PoorManQ45]

O.k. but how is most damage to speakers caused? With too little power supplying the amplification, that's how.

But on the other hand, absolutely do NOT underpower those subs. Distortion kills woofers much quicker than power does in most situations.

Wrong!

Distortion does NOT kill speakers, power does.

Take a sub tha tcan truely handle 2000w RMS and put a 200w amplifier on it. Cause that amplifier to clip all day long and you'll find that there won't be ANY harm done to the driver.

Power kills drivers, not power

[Shade240sx]

Hey poormanq45.. i wassent talking to u.. im new to this forum, n i didnt knew of quick reply... my bad ese...

[audtatious]

PMQ is absolutely correct. Underpowering a sub won't cause it to blow up. Pumping clipped signals will. If underpowering caused subs to blow, then the only thing a radio would have is an on and off button.

[PoorManQ45]

If underpowering caused subs to blow, then the only thing a radio would have is an on and off button.

Good explaination.

Pumping clipped signals will.

Remember to always mention that it'll only cause damage if the clipped signal is at a power level greater then what the VC can thermally and/or mechanically handle.

A clipped signal measuring 200w max won't damage a VC that can handle 1000w RMS.

Other then that, thanks for the backup

[audtatious]

I was hoping that was self explanatory

[Kraayl]

I need to know how the hell to mess with the ohms on the subs. They are 3 ohm and i want them at 2. Fool at works says to just run one sub to the other than that sub to the amp. I have no idea what im doign and dont want mess up. Advice?

[audtatious]

That will give you a 1.5 ohm load in parallel or 6ohm in series.

[PoorManQ45]

Ok, it can be done. But you're going to need a LOT more subs

[Kraayl]

Well more subs is not an option....So parallel being what i described? sub to sub then one sub to amp?

[PoorManQ45]

Whast amp are you using?

If you can get an amp that will handle a 1ohm load you'll be able to wire two of those subs in parallel

[Kraayl]

Its a fosgate a 500/2...Im too lazy to look at the exact model right now, i beleive its a t5002