I posted the following on the tech talk forum at Parts Express and the consensus seemed to be that a truly good sounding speaker could not be done this way. I'm still intrigued by the idea though and wonder if anyone here is aware of an available, proven, design using a capacitor only crossover that sounds really good. Thanks!
Hi Guys,
A confession, I still subscribe to The Absolute Sound, despite disagreeing with most of what it represents. Anyway, the current issue very favorably evaluates the Watkins Generation Four speaker which is a compact two way using a "modified" Peerless 6.5 inch woofer, a SEAS H-1212 tweeter and a single capacitor as a 3K crossover. The manufacturer claims that because of the matching of the drivers, no tweeter padding is required, no more complex crossover is needed, and that therefore sonic problems caused by more complex crossovers are avoided.
I'm a person who would like to use the very simplest crossover possible in my first two way build. So, I'm wondering if there are any good DIY designs using just a single capacitor for the crossover?
The Watkins cost $2K per pair and the reviewer gushes that he would, " happily recommend it even at a price tag of $7k". I don't trust most of what I read in TAS, I do trust input from forum members here and would greatly appreciate getting info on any good 2 way design that you are aware of that uses only a single capacitor as a crossover.
Thanks!
Jay
Hi Guys,
A confession, I still subscribe to The Absolute Sound, despite disagreeing with most of what it represents. Anyway, the current issue very favorably evaluates the Watkins Generation Four speaker which is a compact two way using a "modified" Peerless 6.5 inch woofer, a SEAS H-1212 tweeter and a single capacitor as a 3K crossover. The manufacturer claims that because of the matching of the drivers, no tweeter padding is required, no more complex crossover is needed, and that therefore sonic problems caused by more complex crossovers are avoided.
I'm a person who would like to use the very simplest crossover possible in my first two way build. So, I'm wondering if there are any good DIY designs using just a single capacitor for the crossover?
The Watkins cost $2K per pair and the reviewer gushes that he would, " happily recommend it even at a price tag of $7k". I don't trust most of what I read in TAS, I do trust input from forum members here and would greatly appreciate getting info on any good 2 way design that you are aware of that uses only a single capacitor as a crossover.
Thanks!
Jay
I'd take a look at that Seas 10" midbass with a nice smooth rolloff at 2kHz, and probably try to add a compression driver on a constant-directivity horn.
Set the capacitor value nice and small so it starts rolling off the HF unit very high up. That'll flatten off the HF droop from the horn, and hopefully match the sensitivity of the midbass by the time it gets down to the low-kHz region.
You'll need a compression driver with ferrofluid to keep the impedance curve nice and smooth, but I see no reason that couldn't be done.
Chris
Set the capacitor value nice and small so it starts rolling off the HF unit very high up. That'll flatten off the HF droop from the horn, and hopefully match the sensitivity of the midbass by the time it gets down to the low-kHz region.
You'll need a compression driver with ferrofluid to keep the impedance curve nice and smooth, but I see no reason that couldn't be done.
Chris
A very VERY smooth and relatively steep natural rolloff of the woofer, and a tweeter with a flat power response (read-waveguide) that can be crossed with a single cap to flatten the "lump" power response and have a crossover transfer f3/f6 a couple octaves higher than the actual "final" crossover point.
Yes, it's doable, but depends on the performance of the mid-bass driver at the top end of its range - some are more than smooth enough to not require LP filtering. My first DIY speaker - almost 20yrs ago now - was a Daline /TL using the absolutely delightful VIFA P13WH and initially a Hiquophon ceramic dome tweeter from Linn Khelidhs, and ultimately a TG27(?) silk dome tweeter. After a few passes at XO, they ended up with a single cap on the tweeter, XO knee around 2500-3200 IIRC.
I don't recall seeing a good design with just a cap as a HP filter but you could do pretty good, considering that minimalist way can't be optimal, with a Peerless HDS 205 PPB, an 8" poly cone midwoofer that you might cross over to a 90 dB tweeter with just a single cap, but it should be placed really close to the wall to counteract the baffle stepp loss of spl. If I were that interested in it, I'd try my luck with a pretty shallow and a very large baffle loudspeaker enclosure to come as close to infinite baffle principle loading as possible. I'd listen to these speakers at approx. 45 deg off-axis horizontally where natural midwoofer HF roll off is sufficiently down to meet the tweeter at maybe 2.5 kHz.
Cap + resistor and you have the Dynaco A25. Now available once more as the A26...
Seas A26 10" 2-way Kit Pair (based on the classic A25)
Seas A26 10" 2-way Kit Pair (based on the classic A25)
I realize that I am asking for a lot here, but could anyone suggest a good pairing of woof and tweet using a cap crossover that would work well in a 30 to 40L cabinet? I wouldn't expect audiophile sound rather, hopefully, something comparable to, or a bit better, than a 1980s "mid-fi" speaker. Also, if possible, with a total cost of all four drivers of under $150!
I am not trying to be totally off the wall here. I strongly suspect this wish list is impossible to achieve, but I also know that some folks here have put together some surprisingly good sounding speakers with unlikely "close out" or "cheap" drivers. The creativity of guys on this forum is amazing to me, so maybe this highly improbable goal is not impossible, if some sacrifice of sound quality can be accepted...
Jay
I am not trying to be totally off the wall here. I strongly suspect this wish list is impossible to achieve, but I also know that some folks here have put together some surprisingly good sounding speakers with unlikely "close out" or "cheap" drivers. The creativity of guys on this forum is amazing to me, so maybe this highly improbable goal is not impossible, if some sacrifice of sound quality can be accepted...
Jay
Not my cup of tea either because it will sound slightly rough, but nothing stopping you starting simple, and later improving the filter.
An 8" bass can be quite well-behaved with nothing more than a coil. People manly use polycones in this context. But this one is the modern equivalent of the SEAS 21 REX: H1288-08 CA22RNX
This 1" tweeter must be similar to a 25 TFFC: H0881-06 27TFFC
Voila. The SEAS Njord kit.
Yeah, I know. But you need the coil here.
An 8" bass can be quite well-behaved with nothing more than a coil. People manly use polycones in this context. But this one is the modern equivalent of the SEAS 21 REX: H1288-08 CA22RNX
This 1" tweeter must be similar to a 25 TFFC: H0881-06 27TFFC
Voila. The SEAS Njord kit.
Yeah, I know. But you need the coil here.
Attachments
I just dug up another one with a 6" polycone bass and metal tweeter. Monitor Audio R852 MD:
You really need a well-behaved bass. The old Vifa PL17WJ is still around. A good candidate with a single coil around 0.5mH if I remember the Marshall Leach speaker correctly. Vifa 2-Way Loudspeaker System
Another might be H1571-08 U18RNX/P
You really need a well-behaved bass. The old Vifa PL17WJ is still around. A good candidate with a single coil around 0.5mH if I remember the Marshall Leach speaker correctly. Vifa 2-Way Loudspeaker System
Another might be H1571-08 U18RNX/P
Interestingly enough, when I measured my Dynaco A25s years ago, there was
a very deep null at the crossover frequency, at least on the tweeter axis.
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