6" woofer cheap at parts express

[Jean]

I understand, experienced it even, but I don't understand why. That is one of life's mysteries to me. Home stereo watts vs car stereo watts.

My Dad's old Magnavox 1964 solid state console stereo would rattle the windows and run us out of the house with loud clean sound. Nice piece of furniture, too (7 ft long and solid teak, I think), but I don't think it was capable of 10 watts.

Now, the living room is much quieter than most cars, and quiet is a force multiplier. But stopped, with the engine switched off, conventional wisdom says the level should be somewhat close. Not even.

Now, maybe my cheap @ss hasn't bought the right speakers (exhibit A is this thread). But I can't imagine those old paper speakers being better than today's materials.

There is no difference between home stereo watt / car stereo watt / pa stereo watt . The difference is in the speakers. There are some crazy efficient home/pa speakers out there with sensitivity ratings at close and sometimes above 105db/watt (or 2.83 volts) at 1 meter. Where you common car audio speaker is in the 80-90 area.

[318Joe]

...Besides, power handling is certainly no indicator of how loud something plays.

If you have ever heard a Lowther speaker running on 3.5 watts, you would understand totally.

I understand, experienced it even, but I don't understand why. That is one of life's mysteries to me. Home stereo watts vs car stereo watts.

My Dad's old Magnavox 1964 solid state console stereo would rattle the windows and run us out of the house with loud clean sound. Nice piece of furniture, too (7 ft long and solid teak, I think), but I don't think it was capable of 10 watts.

Now, the living room is much quieter than most cars, and quiet is a force multiplier. But stopped, with the engine switched off, conventional wisdom says the level should be somewhat close. Not even.

Now, maybe my cheap @ss hasn't bought the right speakers (exhibit A is this thread). But I can't imagine those old paper speakers being better than today's materials.

[StereoInstaller1]

lots of more serious components are rated in "full range" power, so a mid that will handle 20 watts full range will handle 100 watts or more if crossed over 100Hz @ 12db/oct.

Besides, power handling is certainly no indicator of how loud something plays.

If you have ever heard a Lowther speaker running on 3.5 watts, you would understand totally.

[Jean]

Tweeters are usually rated lower in power than mids/woofers. They don't need lot's of power to get loud, so you'll be fine.

[318Joe]

Thanks, the vifas with the proper crossover components for the jamos puts the total at about $35. I will have to go easy on the volume, however as these are only rated @ 20wrms.

Quality, power , price. Pick any two, eh?

[Jean]

Mylar tweeters = garbage.

You can pick up a set of stock bmw tweeters from 93+ cars, they sound smoother/cleaner than the mylar crap.



The vifa one looks good as well, I would get that.

[318Joe]

Update:

Speakers installed up front. Replaced a set of cerwin vega 6" separates.

Much warmer sound. The cerwin vegas were not bad, but they seemed to be a bit harsh in the midrange using the cerwin vega crossovers paired with the factory tweeters.

Couple of points. First: heaven only knows what is inside that cerwin crossover (just a cap I'm sure) or what frequency it starts at. Second: Some of the "warmth" of that Jamo is probably due to that speaker dropping off at @3500. But, the bass was noticably stronger with some thumping happening in the kickpanels. These are going to sound nice if I can get the crossover and tweet sorted out.

As nice as the factory tweets are with the stock speakers, it is unlikely they will sound happy with these jamos, so while I'm having to make a custom crossover, I might as well use a better matched tweeter.

Soooo while shopping for the crossover components...

These roll off at about the frequency the Jamos are rated at:

http://www.parts-express.com/pe/pshowdetl.cfm?&Partnumber=279-061

These would fit in the factory pods without much modification:

http://www.parts-express.com/pe/pshowdetl.cfm?&DID=7&Partnumber=264-1018&ctab=1#Tabs

and moving a little higher up the scale, I think these can be modified to fit:

http://www.parts-express.com/pe/pshowdetl.cfm?&DID=7&Partnumber=275-040&ctab=2#Tabs

Don't know if that last set is worth the 300% higher price of the first set, and it is at the top of the budget range.

[318Joe]

Yep, a lot has to do with driver selection, but if you are working with what you have to will be playing with various crossovers.

Daytons aren't bad, but you don't want to cross those high either (at least a 4-5" mid can be safely crossover high vs a 6) :)

The usual paper cone drivers normally can be crossed higher vs the more exotic cone material mids w/o having to also implement notch filters etc...

I just want to know where I can find a high res version of your sig!

[318Joe]

I wish I could get 200 or so people together to do a serious group buy. I know I could spec something out that would WORK, and meet everyones needs, cheap.

I'm in.

In the meantime, I'll crossover these and see how bad it sounds. Who knows, maybe it will be the same hole in the frequency response that made Mr. Bose so famous...

BTW the car will have the infamous Luke starter kit (box, crusher, premiums and 4ch amp) but the amp I have is a bit too much for the premiums, and I was thinking ahead...and trying to get to free shipping on the sub.

[Jean]

Yep, a lot has to do with driver selection, but if you are working with what you have to will be playing with various crossovers.

Daytons aren't bad, but you don't want to cross those high either (at least a 4-5" mid can be safely crossover high vs a 6) :)

The usual paper cone drivers normally can be crossed higher vs the more exotic cone material mids w/o having to also implement notch filters etc...

[StereoInstaller1]

Yup, a huge one.

One of the many reasons the vast majority of "car audio" speaker "systems" do absolutely nothing about the bandpass or simple low pass crossover.

IMO, the way to do it best is find a driver with a natural 6db/oct rolloff so you need very little crossover. That generally is rare and expensive (Dynaudio and Morel) or this new chinese driver over at Parts Express. Look at the response graph and you will see how a simple 6db crossover at 5Kish would clean that response up beautifully.

However, those are $140/pr and WILL NOT fit the hole of an E30, and I don't think they could be made to do so.

So on to something cheap and effective that WILL fit, and could even be made to angle: the Dayton Aluminum cone 4". About $15 each, decent power handling, easy/cheap crossover, but back to the same old hassles of home audio drivers in a car: no power handling, 8 ohms means you are wasting amp power, low Qts means very little mechanical cone control at low frequencies and it lacks "robustness"...but it is cheap!

I wish I could get 200 or so people together to do a serious group buy. I know I could spec something out that would WORK, and meet everyones needs, cheap.

[Jean]

Use the rating of 6ohm, because the 1st order filters are very "shallow" they don't both have to be at the same crossover point. So, even though you are crossing over at 3k or whatever it will still play 4khz and 5khz (crossover is not like an ON/OFF filter, you have to go higher and higher in order 24db and UP (usually done actively as the component count in such a high order passive crossover will make your crossover the size of your glovebox lol) and if you do crossover at the same point sometimes you get a "bump" at that point... just give it a shot and see how it sounds.

[318Joe]

Stock crossover is 1st order (one cap for high pass in series; one inductor in series for low pass).

Typically a 6" speaker starts to "break up" or "beam" at 2500hz or more. So, with the 1st order that would be your starting point, or even less (2k-2.5k for example) since a 6db slope is very gradual vs. 12db, 18db, 25db etc. But the issue is the stock highpass crossover point for the 8ohm tweeter is at almost 6kHz, because it's 1st order. The higher order you go the lower crossover point you can pick (up to a point), because with shallow 6db (1st order) it can't keep the lower freq. away from the tweeter if the crossover point is low, so the stock one is pretty high.

So for calculating the Jamo should I use the advertised rating of 6ohms or the re of 4.5?

6 ohms would give me about a .48 inductor rolling off at about 2k, 4.5ohms would be a .35.

Isn't that going to leave a hole from 2-6k?

[318Joe]

If you plan on using the same stock tweeter, use the same value cap for the high pass.

You can use this online calculator to figure out needed values:

http://www.carstereo.com/help/Articles.cfm?id=55

Stock crossover is 1st order (one cap for high pass in series; one inductor in series for low pass).

Typically a 6" speaker starts to "break up" or "beam" at 2500hz or more. So, with the 1st order that would be your starting point, or even less (2k-2.5k for example) since a 6db slope is very gradual vs. 12db, 18db, 25db etc. But the issue is the stock highpass crossover point for the 8ohm tweeter is at almost 6kHz, because it's 1st order. The higher order you go the lower crossover point you can pick (up to a point), because with shallow 6db (1st order) it can't keep the lower freq. away from the tweeter if the crossover point is low, so the stock one is pretty high.

So, to keep it simple you can even re-use the inductor from the stock speaker to see how it works...and then try other values if needed (partsexpress sells a bunch of different inductors / caps for crossovers). For audio use do not use polar electrolytic caps, use non-polar at the very least.

Thanks for the help.

[318Joe]

In the interest of not providing a single word answer, sure.