The woofer needs to be up to 10db more efficient than your widerange speaker. That's because you will throw away a lot of that efficiency to get the extension. This is if you're going passive. If you're going active then efficiency matching doesn't matter at all.
Great point...
Assuming you want flat response throughout the range..
Most do, I realize..
Also... In most cases.... the widerange usually has a much greater impedance peak than does the woofer...
Negating somewhat, the difference..
Assuming you want flat response throughout the range..
Most do, I realize..
Also... In most cases.... the widerange usually has a much greater impedance peak than does the woofer...
Negating somewhat, the difference..
More efficient seems more "alive" some how. My triple stack per channel 15" woofers are each rated at 6db more efficient than each of the two planar midranges I use. With 15 times the available power driving the woofers, than the mids, they are much happier than with 15 class A watts available to them, despite their 98/97db efficiency rating. Surprisingly, the bass is more improved than the rest of the spectrum, when flooded with 2nd harmonic distortion from an inexpensive tube linestage.
I tried 4 RSS265HF-04 10" drivers, in Linkwitz-like bass bins, but they can't keep up with the planars.
Destined for deep deep bass, in a cinema sealed box, I guess.
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GRS 12PF-8 12" Paper Cone Foam Surround Woofer
Anyone used this? Know where can get a response curve?
Price seems too good to be tru
Anyone used this? Know where can get a response curve?
Price seems too good to be tru
last Fall my home brewed OB got a face lift and an update: the lower mid driver changed from Visaton B200 to AL200. Wider dispersion now. SQwise: as much as B200 could sound good, with this setup one realizes that it was still a distortion that sounded good. Now it sounds both more accurate and still good (better); with good recordings of course (disclaimer).
The active Xover had to change quite a bit. They are still operated as a 3-way. I may still implement the tweeter passively, though I cannot hear up there but maybe for the kids and the neighbour's dog 🙂. The star of this setup is the 4" Scanspeak which is such a fantastic driver. With AL200 under, the small SS got an even bigger role to play and still does the job with no signs of strain.
btw drivers are listed in my previous posts:
https://www.diyaudio.com/forums/multi-way/123512-ultimate-baffle-gallery-225.html#post4970383
p.s. in the picture my DIY F5+ACA amp is missing top cover since the grill is being changed (the amp was overheating in Summer).
The active Xover had to change quite a bit. They are still operated as a 3-way. I may still implement the tweeter passively, though I cannot hear up there but maybe for the kids and the neighbour's dog 🙂. The star of this setup is the 4" Scanspeak which is such a fantastic driver. With AL200 under, the small SS got an even bigger role to play and still does the job with no signs of strain.
btw drivers are listed in my previous posts:
https://www.diyaudio.com/forums/multi-way/123512-ultimate-baffle-gallery-225.html#post4970383
p.s. in the picture my DIY F5+ACA amp is missing top cover since the grill is being changed (the amp was overheating in Summer).
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That GRS 12PF-8 has a very high QTS and low Xmax. It might need an H-baffle to air load and a multiple stack of 4-8 per side to do bass at good SPL.
GRS has a similar 12" GRS 12SW-4 12" Poly Cone Subwoofer 4 Ohm that has over twice the Xmax and a much better QTS for only twice the price, so its arguably better value for money?
cover the holes on your baffle with thick pure wool felt and you will get much better extension from your mid drivers...
Koja, nice implementation of an OB, a lot of space behind the drivers 🙂 . I am still using Visaton B200, albeit with a phase plug.
I had also tried Fostex FE206e, but was not happy with it, Visaton sounds better in an OB...
Regards,
Vix
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As for giving credit where credit's due: SL continues to live in my home 😉:
LXminis are currently off duty and LX521s are waiting for spring to be finished.
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I wanted to ask the same question. I was expecting to see a slot loaded woofer, but this..I was baffled 😀
Maybe it sounds better that way, reduces some peak or something. Easy to try (with or without slot)...
^An old trick, Karlson.
A slot is to make dispersion of a large driver wider. It creates some diffraction and most likely some more distortion too, in the cavity between membrane and plate.
A slot is to make dispersion of a large driver wider. It creates some diffraction and most likely some more distortion too, in the cavity between membrane and plate.
Hi.
slot loaded in in bass unit can lowered Fs and also Qts, I have a pair of OB speakers with slot loaded woofer.
Slot load a full range are totally different, as rules of thumb, the slot area should be 1/3 of Sd of your driver but I always fine tuned carefully using thick cardboard, and after finalised, I use ply wood instead.
Please read comment in youtube for further info + patent article # US2646851 (A) . Mr. Gilbert Briggs also mentioned in his article too ( Wharfedale SFB3 prototype ) . thank you.
An externally hosted image should be here but it was not working when we last tested it.
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