My Lil' Buddy on OB is coming along nicely. Alpha 15 below. I am experimenting with compression tweeters and horns. This is a pretty innexpensive option using a Pyle PSD442 and the aluminum Selenium horn. It sounds great crossed at 1600Hz. I like it just fine. I also have the B&C DE250 everyone loves... it's a great tweeter.
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GPA 414 is a complete waste of money as slot loaded subwoofer
i would use one per side for mid bass duty (instead of the AE)
sell the rest and refill the SLOB with cheaper PA drivers
$$$ wise
Here's my prototype OB using the Z-Frame (KaZba) that xrk971 was working on in another thread - although I didn't use the Karlson wings that he used. I thought it sounded better without them. So far I've only measured the woofers (attached).
Two GRS 12PF woofers
Eminence Alpha 8A
Selenium D220Ti tweeter
PRV Audio WG35-25-B waveguide (I also tried the Pyle PH612)
Zilch/Jackgiff Econowave x/o for the Alpha 8A and D220Ti
Two GRS 12PF woofers
Eminence Alpha 8A
Selenium D220Ti tweeter
PRV Audio WG35-25-B waveguide (I also tried the Pyle PH612)
Zilch/Jackgiff Econowave x/o for the Alpha 8A and D220Ti
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Kec, you and I are on a similar track. I took the easy way out by using a standard pre-built 1.6k crossover but the photo doesn't show the 6 capacitors connected to the L-pad to 'fix' the sound of the standard crossover. I have so many horn lenses including the PVR and the PH612 (which never seems to stay in my system long).
Here are measurements I made of various horns.
https://speakerprojects.wordpress.com/2016/12/30/waveguide-comparison/
How do you feel about the Eminence Alpha 8A? Every Eminence woofer I've tried (12lta, Beta 10A, Lil' Buddy and one of the 8" models available at PE (not the Alpha 8) always impress me... and I've been thru my share of Vifa, TB, Dynaudio, etc.
I'm beginning to think just about any decent woofer on open baffle sounds great as long as it has good support on top and bottom.
Here are measurements I made of various horns.
https://speakerprojects.wordpress.com/2016/12/30/waveguide-comparison/
How do you feel about the Eminence Alpha 8A? Every Eminence woofer I've tried (12lta, Beta 10A, Lil' Buddy and one of the 8" models available at PE (not the Alpha 8) always impress me... and I've been thru my share of Vifa, TB, Dynaudio, etc.
I'm beginning to think just about any decent woofer on open baffle sounds great as long as it has good support on top and bottom.
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I like the Alpha8A too. Always wanted to make a two way with their horn tweeter on an OB. The bare Alpha8A sounds nice but the Alpha 6A is better but looses out due to lack of low end on an OB.Eq is possible but not sure how that would sound besides restricting it's power capability. However both are very efficient and this may not matter much in actual use.
Too many projects and too little time !
I am using Audiolense XO (on a windows pc) and a 8 channel RME Fireface USB soundcard.
Very easy to get good sound with this setup. Just playing around with different drivers in and out. FIR filters with automatic time alignment.
Hi everyone, I built these based on lampizator p17 OBs. xover is lampizators. Being in New Zealand Saba greencones and altecs are expensive so I sourced out Plessy 5x7 midbass, Philips paper tweeter and philips 12 inch woofers. the baffles are covered in polar fleece to eliminate diffraction. they are very good imo. the orange amp is my tda2030a chip amp btw.
Hi folks, I am building an open baffle project inspired by Lampizator P17 also. My question is, how does the polar fleece on the baffle help with the sound? Is it noticeably better than bare wood/MDF? Thanks!
I always thought diffraction was frequency irregularities brought on by sharp edges redirecting higher frequencies , either fr om the baffle edges, or the plates or frames of non flush mounted drivers.
I suppose the polar fleece would dampen or eliminate those shorter wave treble problems.
It would help eliminate baffle reflections as well, so that would assist with imaging .
The downside , if you like the look of it, is cats may thank you for the big noisy scratching posts .
Hi MITsound,
Thank you for the explanation. That sounds like a nice addition to the project, although I very much prefer the looks of bare wood, even if it's just plain MDF.
I find it's better to try these things , for yourself. I've been told point blank, a few of my ideas wouldn't work well, and empirically, they worked very well.
Sims are an excellent starting point, but fine adjustments to suit one's personal tastes, ought to be tweaked by ear. Otherwise, we'd all look at graphs on powered pro monitors, and buy those.
I feel the mid band of the Alpha6A is better than the Alpha8A but overall the Alpha 8A sounds better because of the extended LF it has.
Like the Eminence CX10 and the CX12. The 10 sounds better in the mids than the 12 but the 12 has audibly better LF and so sounds 'fuller' . But I guess you can eq all drivers to sound similar. Wonder if the mids would sound different then ?
I Think the problem are the THD of the Chassis. A smaller Mid-Driver for Open-Baffle must have more Xmax. The Xmax of the Alpha6a is small for a 6-incher in Open-Baffle. So you will drive it in higher THD than a equal 8-incher as same dB. The bigger the cone the less can Xmax be. Some people like more k2 as to see in Tube-Amps. But is it what we want?
Sorry for my english, I hope you understand....
Sorry for my english, I hope you understand....
Hello all, while tuning an enclosure design, I noticed the qts. specs were very similar between a Scanspeak tweeter, a Scanspeak Revelator woofer, and some RSS 265HF-4 subdrivers.
As long as they're in free air.
The sound seems much more coherent than using unmatching qts. drivers together.
I hadn't expected qts. to matter at the 2000 hertz crossover point, but this sounds better than that woofer in a sealed box tuned to a 0.707 qts. Is this just random chance, or does qts. matter even at relatively high frequencies, compared to midbass, say @ 130 hertz?
I know, this is a gallery, but I was hoping for some advice from experienced builders.
If it's an inappropriate forum for this, I welcome advice in a pm. Thanks, all.
As long as they're in free air.
The sound seems much more coherent than using unmatching qts. drivers together.
I hadn't expected qts. to matter at the 2000 hertz crossover point, but this sounds better than that woofer in a sealed box tuned to a 0.707 qts. Is this just random chance, or does qts. matter even at relatively high frequencies, compared to midbass, say @ 130 hertz?
I know, this is a gallery, but I was hoping for some advice from experienced builders.
If it's an inappropriate forum for this, I welcome advice in a pm. Thanks, all.