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SB acoustics 15CAC or Seas W15?

J

j_s

pfm Member
I'm currently building a 3 way speaker and was unsure what midrange to go for. Tweeter is Scanspeak R2904/70005, bass is Kef B139. I was thinking of using either the SB acoustics SB15CAC30 or the Seas W15CY001. I'm using a minidsp flex8 as a crossover.
 
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SB Acoustics Satori MR16P-8 Midrange Speaker

The SB Acoustics Satori MR16P-8 is a high performance 6½ inch 8 ohm midrange loudspeaker drive unit featuring a unique composite cone made of paper and Egyptian Papyrus™ fibres. The cone is lightweight, rigid and has high internal damping resulting in excellent detail. Also available in 4 ohms...
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The W15CY001 has a pretty mad break up at around 8khz than needs dealing with as a midrange.

I have a pair, they are nice drivers, but for a midrange, I might look at something without such a breakup. The CA15 paper cone could be considered.
 
Good suggestions. I had read about the Seas breakup at high frequency, with the Scanspeaks needing a high crossover point themselves (around 2750hz) it's probably best to go with something better behaved at higher frequencies.
 
What is your intended range? For a typical midrange, I'd expect it to be high-passed at no less than 250Hz and high-passed at no more than 3kHz. For such an application, I think you could do worse than either the Seas CA15RLY or ER15RLY. But...

Your choice of Scan-speak R2904/70005 for tweeting duties might suggest you want a higher quality mid driver. Having used the Seas CA15RLY in one of my designs, I find it is bettered by Seas own M15CH-001 (no longer available) and Scan-speak 15M/8631G00. There are even more exotic mids around, of course, but if I were you, I'd reconsider your choices. The B-139 might have been legendary in its time, but it is now well surpassed by newer designs. For a slightly more modern woofer of equivalent parameters, consider the Scan-speak 25W8565-00. It works really well in a sealed box.
 
Also, how much do you want to spend? The Seas drivers you mention are three times the price of the SBs.
 
Have you seen the price of the Scan-speak R2904/70005? The Seas CA or ER15 are chump-change in comparison.
 
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James said:
Have you seen the price of the Scan-speak R2904/70005? The Seas CA or ER15 are chump-change in comparison.
Click to expand...

Sorry, I wasn't clear - I was referring to the drivers mentioned by the OP. The Seas W15CY001 are £275 each, while the SB15CAC30 are about £90 each.
 
j_s said:
Was going to use the B139's in an isobaric configuration.
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Well, its been done before. 😁 I hope you have some beefy amps - they'll draw lots of current, and still be quite low efficiency.

You're planning to spend a fair bit on mids and tweeters - I assume you plan to measure and equalise? That will be essential if you want results commensurate with the expenditure, I'd say.

Regarding mid choices, the drivers you suggest are both hard cones - maybe that's why you picked them? Of the two, I'd lean towards the SB ceramics, because they (and the similar NAC aluminiums) have unusually well controlled break-up for hard cones, so they ought to be easier to work with than others of the type. Paper cones, like the Satoris and Seas suggested above, would also avoid the strong out-of-band peak of the magnesium Seas excels.

If I'd your budget for mids, I'd also be tempted by the SB MW13TX textremes. Or, if I could stretch a bit further, the Purifi 4".
 
I've got REW on my PC, a UMIK and I'm going to be using a minidsp flex8 with dirac. So hopefully that'll be okay to measure, equalize and correct phase.
 
j_s said:
Was going to use the B139's in an isobaric configuration.
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The only benefit of isobaric configuration is to reduce cabinet volume. By the time you allow for the coupling cavity, the box volume is probably closer to three-quarters rather than half. It also complicates construction. Much easier to just make a bigger box, I say.
 
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Had good memories of my isobariks with active nap250s I had back in the 90's, hence the choice. Just wish they'd have better detail in the mid/treble.
 
I chose the ScanSpeak Discovery 15W8434G0. Very smooth, minimal nasty resonances. Maybe too cheap to be taken seriously?


pinkfishmedia.net

DiscoCAT Speaker Design

After my success at (dramatically) improving my IPL M4 kitchen speakers, I decided to attempt a small 2-way speaker design that would beat my Murphy CAOW1s - not a trivial target! https://pinkfishmedia.net/forum/threads/improving-ipl-m4s.273191/ I've had the CAOW1s for about 10 years and for...
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S-Man said:
I chose the ScanSpeak Discovery 15W8434G0. Very smooth, minimal nasty resonances. Maybe too cheap to be taken seriously?


pinkfishmedia.net

DiscoCAT Speaker Design

After my success at (dramatically) improving my IPL M4 kitchen speakers, I decided to attempt a small 2-way speaker design that would beat my Murphy CAOW1s - not a trivial target! https://pinkfishmedia.net/forum/threads/improving-ipl-m4s.273191/ I've had the CAOW1s for about 10 years and for...
pinkfishmedia.net pinkfishmedia.net
Click to expand...
The response certainly looks good on the datasheet. The breakup at 5-6 kHz is well controlled, though I see Troels uses a series trap to tame it further in his Ellam Discovery 15.

Edit: actually, I see there's a dedicated mid - the 15W8424 (used in Troels' Discovery 3WC-10), which has an even smoother looking response in the breakup region. Probably better than the 8434 for a 3 way.
 
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