Great speakers on ebay for cheap!!!

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Hey guys,
I posted this in the parts forum, but figured this was a good spot too, since this is where I spend most of my time, LOL.

Anyways, here is my original post.

Just wanted to give you a heads up on some great speakers I found on ebay. I bought 10 speakers for $80 which I thought was a great deal, wish they had this lot of 50.

50 Lot of Aura Sound Speaker 4" Full Range Vintage Car Home Pair Midrange | eBay

I got mine this morning and hooked them up with some little class D amps I have and they are incredible!

Anyways, just wanted to pass the link on. I love this forum, I have learned so much from everyone. Thanks you guys!
 
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Quote from Beyma spec sheet: "The Xmax is calculated as (Lvc - Hag)/2 + Hag/3.5, where Lvc is the voice coil length and Hag is the air gap height."

Faital Pro use: "Xmax = [(Winding Depth - magnetic gap depth)/2] + (magnetic gap depth / 3)"

Me being silly/nitpicking: So on this particular speaker you'd get a negative value xmax since lvc is shorter than hag.

Anyway, that would probably be 2.95mm xmax using Beyma's slightly more conservative method, without me being difficult.

Edit:
What's the point of that little wizzer? measured off axis response? Probably the source of the 14khz breakup peak. May be better without it.
 
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Fair enough; would take a BL vs. xmax test to know for sure.

I believe whizzers are to increase HF output, but more here

http://www.diyaudio.com/forums/full-range/195018-how-does-whizzer-cone-work-tips-whizzerectomy.html

Yes, I do understand the intended function of those things.
I do not understand the point of using one on this specific driver, it may have some function when the driver is in a car door pointing directly at your leg, but when used as a regular loudspeaker component it's working under different criteria than it's originally intended purpose. This is a 4" driver after all, moving mass is already fairly low on this driver, the whizzer is probably causing more disturbances than anything else. All things considered, my personal choice would probably be to remove it if it was my driver.
 
Someone may want to use them full-range, in which case removing it will lose some treble.

My assumption is that you will get a smoother response on this particular driver ie loose the breakup peaks, but not much else if removing the whizzer, since the driver is so small and mms so low the whizzer is more of a hindrance than anything else.
 
How you decide to build your system is a matter of which compromises you are willing to go to. It does not matter what kind of system you have, nothing is for free. A 4" driver may not be the best tweeter, but then again a 1" driver is not so good to run fullrange, and then you're stuck with other compromises such as crossovers, driver matching and so on.

I've never been 100% satisfied with any system, but they've all had their positive points. I remember the sonic signature on the 10" cast frame Audio Nirvana in BLH combined with a 12" pioneer also in a BLH with simple 1st order filtering and a KT88 UL tube amp was very engaging, incredible slam and "lifelike" sound, but tilt your head a few cm and you're out of the sweet spot, not to mention the noise floor of the tube amp connected to sensitive speakers. Now I've dug out the 10" Sterling Silver Iris + Beta15 OB and Beyma 12BR70 T-TQWT from storage, use some minidsp with 4th order bessel and TPA3116 amps, the speakers are hard to locate when you close your eyes, sweet spot is wider, but the sound is nowhere near as tight and lifelike as on a big FR driver. I also miss the sonic signature of tubes, but IMO tube amps are best when mating with FR drivers. The 10" coax does a good job, but I often miss many of my previous systems, all of them with different sonic signatures both for the good and bad. Really liked my previous 4way with 2*LM3886 and 2*LM4780 on +/-24v dual mono battery supply, most silent setup I've had, dead quiet, but that is not compatible with my life at the moment.

So now it's all TPA3116 with SMPS that does the job here, it's a the set of compromise that I am currently willing to choose, but with that combination right now I'm working out how to utterly reduce the noise floor. Not sure if battery psu is the best for TPA3116 but I may give it a go since it would not take so much space and therefore easier to childproof. Would be easy to throw in some timer for a battery charger and delay circuits for power up cycle. Not sure if it's worth it.

Anyway, everything you decide/choose is a compromise! Nothing is free!
 
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