Any opinions/ suggestions on running the Scan-Speak 15w8530k00 full-range with no x-over?
http://www.scan-speak.dk/datasheet/pdf/15w-8530k00.pdf
I am currently using the Seas W12CY003 E0044 in a .25 ft3 Parts-Express cabinet with a tweeter/L-Pad added above 12kHz.
As you can see, the bass drops off much quicker than the Scan-Speak. It does have a phase plug so maybe better H-F than the Scan-Speak?
http://www.seas.no/images/stories/excel/pdfdataheet/e0044_w12cy003_datasheet.pdf
Madisound recommends trying a passive radiator to eliminate the 40hz bump but I like the coherency of a single driver. Wouldn't the P-R be like a separate bass driver and not be in-phase? That is 2 sound sources, not one so there will be sound wave interactions between the two.
That is why I am looking at the Scan-Speak for the flatter bass response - IF you can trust the published curves.
Thanks
http://www.scan-speak.dk/datasheet/pdf/15w-8530k00.pdf
I am currently using the Seas W12CY003 E0044 in a .25 ft3 Parts-Express cabinet with a tweeter/L-Pad added above 12kHz.
As you can see, the bass drops off much quicker than the Scan-Speak. It does have a phase plug so maybe better H-F than the Scan-Speak?
http://www.seas.no/images/stories/excel/pdfdataheet/e0044_w12cy003_datasheet.pdf
Madisound recommends trying a passive radiator to eliminate the 40hz bump but I like the coherency of a single driver. Wouldn't the P-R be like a separate bass driver and not be in-phase? That is 2 sound sources, not one so there will be sound wave interactions between the two.
That is why I am looking at the Scan-Speak for the flatter bass response - IF you can trust the published curves.
Thanks
Chuck,
Interesting choice of drivers. These are both near 'state of the art' midbass drivers, somewhat remniscent of the KEF B110. The SEAS is a little more extended in the HF and somewhat smoother. The frequency response graphs are for the drivers mounted on a test baffle. The bass in these graphs is not the response you will get from a particular enclosure. The 40 Hz hump (Scan-Speak) is actually a response 'remnant' between cancellation notches, probably due to reflection from a nearby surface ('floor bounce'). There is no need to compensate for it. The extended HF of the SEAS (relative to the Scan-speak) is likely due in part to the phase plug. Both are fine drivers with a healthy Xmax, so some real bass is possible. However, that will not be achieved with a simple sealed box or BR. A passive radiator or some variant of a tuned pipe will likely provide good results. There will be some phase shift associated with either one, but it will be largely inaudible. You will likely need to pick up some modeling software and run some sims. Have fun.
Bob
Interesting choice of drivers. These are both near 'state of the art' midbass drivers, somewhat remniscent of the KEF B110. The SEAS is a little more extended in the HF and somewhat smoother. The frequency response graphs are for the drivers mounted on a test baffle. The bass in these graphs is not the response you will get from a particular enclosure. The 40 Hz hump (Scan-Speak) is actually a response 'remnant' between cancellation notches, probably due to reflection from a nearby surface ('floor bounce'). There is no need to compensate for it. The extended HF of the SEAS (relative to the Scan-speak) is likely due in part to the phase plug. Both are fine drivers with a healthy Xmax, so some real bass is possible. However, that will not be achieved with a simple sealed box or BR. A passive radiator or some variant of a tuned pipe will likely provide good results. There will be some phase shift associated with either one, but it will be largely inaudible. You will likely need to pick up some modeling software and run some sims. Have fun.
Bob
Thanks Bob. Yes, these is noting like running a driver full-range with no x-over. The clarity is unmatched. Dynamics are surprisingly good even with my little 45wpc Zamp v3 which puts out 12 amps.
It is easy to hear the sound deterioration with a tone control or pre-amp. A haze is added and dynamics are reduced. I think maybe an active pre-amp would be needed to run the driver with a tone control.
I have been relying on Madisound and part-Express to model this for me. Attached are the FR with the speakers 51" and 41" out from the wall both 3 feet away and about 10 feet away at the couch. Sorry about the poor resolution but Diy won't allow 600dpi scans - too large.
Could you tell me what are the 3 lines on the Scan-Speak F-R curves? Are they 0 / 30 / 60 degrees or something else?
It is easy to hear the sound deterioration with a tone control or pre-amp. A haze is added and dynamics are reduced. I think maybe an active pre-amp would be needed to run the driver with a tone control.
I have been relying on Madisound and part-Express to model this for me. Attached are the FR with the speakers 51" and 41" out from the wall both 3 feet away and about 10 feet away at the couch. Sorry about the poor resolution but Diy won't allow 600dpi scans - too large.
Could you tell me what are the 3 lines on the Scan-Speak F-R curves? Are they 0 / 30 / 60 degrees or something else?
Chuck55,
A couple of thoughts...
The 15w would probably need a correction circuit. I've heard it in commercial design with a 1st order crossover (cap and coil) and it sounded pretty darn good, but the 15w breakup was audible. Without the coil it probably would have been worse. I've also heard it in a diy design with a Hiquphon tweeter and it was the best small 2-way that I've heard. Both needed some power to come alive, but the bass was unbelievably good regardless of the small size of the speaker. I've never heard the Seas, but the curve looks much flatter.
I would surmise 0/30/60 on the SS curves. The 5" driver gives up a lot off axis which narrows the sweetspot and could deaden the sound.
In the alternative, SS has a 4" Discovery driver with a very flat frequency response curve, which may not need a correction circuit.
Or a Fostex or Markaudio 4" driver in one of P10's cabinet (designs).
A couple of thoughts...
The 15w would probably need a correction circuit. I've heard it in commercial design with a 1st order crossover (cap and coil) and it sounded pretty darn good, but the 15w breakup was audible. Without the coil it probably would have been worse. I've also heard it in a diy design with a Hiquphon tweeter and it was the best small 2-way that I've heard. Both needed some power to come alive, but the bass was unbelievably good regardless of the small size of the speaker. I've never heard the Seas, but the curve looks much flatter.
I would surmise 0/30/60 on the SS curves. The 5" driver gives up a lot off axis which narrows the sweetspot and could deaden the sound.
In the alternative, SS has a 4" Discovery driver with a very flat frequency response curve, which may not need a correction circuit.
Or a Fostex or Markaudio 4" driver in one of P10's cabinet (designs).
Thanks Ultrakaz.
Maybe I should stick with Seas, either passive radiator on the W12 or go with the W15 in a .5 ft3 cabinet.
I found this Discovery driver but it looks like it has a bad breakup too if run full range.
http://www.scan-speak.dk/datasheet/pdf/12w-4524g00.pdf
I should have written that the breakup was audible above normal conversation level and really assertive at a very loud level. At lower levels it was very listenable especially on well recorded acoustic jazz.
The 12w breakup appears quite controllable with a notch in a conventional 2-way crossover-ed speaker, but not for full range use.
The SS driver I was referring to:
Scanspeak Discovery 10F/8424G 4" Midrange 8 ohm: Madisound Speaker Store
Zaph measured the 4 ohm version:
http://www.zaphaudio.com/temp/Scan-Speak-10F-4424G00-FR.gif
FS is high so you will need some type of bass support.
The 12w breakup appears quite controllable with a notch in a conventional 2-way crossover-ed speaker, but not for full range use.
The SS driver I was referring to:
Scanspeak Discovery 10F/8424G 4" Midrange 8 ohm: Madisound Speaker Store
Zaph measured the 4 ohm version:
http://www.zaphaudio.com/temp/Scan-Speak-10F-4424G00-FR.gif
FS is high so you will need some type of bass support.
That is not good. Maybe it's the fiberglass cone. Funny how Scan-Speak writes:
"The slices are filled with damping glue, which dramatically reduces breakup
modes in the diaphragm."
I don't hear any with the Seas after break-in. I have used untreated paper coats before and I know what you are saying about nasty breakups. Coating with Mod-Podge or C37 has solved the problem. I wouldn't dare do that with the Scan Speak as looks like it already has a coating and could dissolve the glue.
For a 4" driver, the Seas W12 does not have the rising response curve and has a 6mm excursion vs 2.6mm excursion. It looks like the better choice. I liked the flat response of the 15W especially in the bass compared to the Seas
I have 4 options. Any opinions would be welcome:
In a .50 cubic foot cabinet:
6" .41 QTS Revelator with a vent
http://www.scan-speak.dk/datasheet/pdf/15w-8530k01.pdf
or
6" Seas Excel with a vent
E0041-08S W15LY001
In a .25 cubic foot cabinet:
6" .31 QTS Revelator sealed box
http://www.scan-speak.dk/datasheet/pdf/15w-8531k00.pdf
or
4 1/2" Seas Excel with a passive radiator
E0044-08S W12CY003
In a .50 cubic foot cabinet:
6" .41 QTS Revelator with a vent
http://www.scan-speak.dk/datasheet/pdf/15w-8530k01.pdf
or
6" Seas Excel with a vent
E0041-08S W15LY001
In a .25 cubic foot cabinet:
6" .31 QTS Revelator sealed box
http://www.scan-speak.dk/datasheet/pdf/15w-8531k00.pdf
or
4 1/2" Seas Excel with a passive radiator
E0044-08S W12CY003
Ultrakaz, if you are still out there - or someone else - I see quite a difference in HF "peaking" (I don't know if this really is an audible breakup mode) between the graphs of different Scan-15W. Which one are you referring you?
Scanspeak 15W/8434G00 Discovery, 5.25" Midwoofer
Yes, THIS one has a huge spike. Maybe because it has a fiber glass, not coated paper, cone.
Scanspeak 15W/8530K-00 5" Revelator Woofer - Low Qts
I don't see the spike in this one. So would any breakup mode be audible?
and the best of the bunch:
ScanSpeak 15W/8530K-01 5" Revelator Woofer
Because of the high Qts vs. low Qts of the K00?
Yikes I just typed a response but couldn't post because my "token had expired." Okay from memory, the driver was the 15W/8530K-00 with the sticky coating. Still the best 5" that I've heard in both commercial and diy designs; tremendous bass response with detailed mids. However, as much as I like it I would not use it without a proper crossover. The breakup is there on axis and at high dbs. Not exactly a "shout" or screech, but more of a movement of the sound image; i.e., vocals come from behind the speaker and then into your lap as the sound level increases.
For purist "full range" or wide bandwidth speaker I would go with a Fostex or Markaudio driver. Keep in mind that even these drivers, all drivers for that matter, have breakup but it is "controlled" better at the expense of bass response.
For purist "full range" or wide bandwidth speaker I would go with a Fostex or Markaudio driver. Keep in mind that even these drivers, all drivers for that matter, have breakup but it is "controlled" better at the expense of bass response.
Ultrakaz, Thanks for writing your response up again. I've had that happen too and know how frustrating that can be! 😡
Ultrakaz, do you think using the ScanSpeak 15W/8530K-01 5" Revelator Woofer in a sealed box would help? It has a higher Qts, smoother looking HF than the -00, and sealed box would limit bass.
I believe the 00 (with sticky coating) has the higher Q and the smoother response. At least according to Zaphaudio.com. However, I have not compared them so I don't know which would sound better running by itself.
Nope, the sealed box would not smooth the breakup of either driver-if that is the question. Nor would a ported box make it worse. Why not try the 00 in a sealed box and see how it sounds as it has the best chance of sounding good? If the breakup bothers you then notch it out. Then if it that does not work turn it into a proper 2-way, just make sure you have enough room at the top of the baffle for the tweeter.
Nope, the sealed box would not smooth the breakup of either driver-if that is the question. Nor would a ported box make it worse. Why not try the 00 in a sealed box and see how it sounds as it has the best chance of sounding good? If the breakup bothers you then notch it out. Then if it that does not work turn it into a proper 2-way, just make sure you have enough room at the top of the baffle for the tweeter.
Yes, that's what Zaph shows. But I cannot find that Scan-Speak 15W8531K-01 driver on Scan-Speak's website. Scan-Speak only makes:
15W/8530K-00 - Low .27 Qts.
15W/8530K-01 - High .41 Qts.
15W/8531K-00 - Medium .31 Qts / uncoated driver
So I don't know what Zaph is referring to.
I also don't know whose graph is more accurate, but the Scan-Speak graphs in the links provided above show the high Qts, coated, K01 to have the smoothest HF response. Zaph does not compare those in his test.
No one seems to have responded to this part of your question. An Auxiliary Bass Radiator(ABR) works the same as a port. The mass of the cone is the equivalent of the air mass in the port (with a much bigger diameter).
So the phase (from the back of the main driver) is reversed, and the output of the ABR is in phase with the driver. For the bass frequencies involved and their wavelength, interference of the outputs of the main unit and the ABR is not an issue.
Thanks Midrange. So is there any advantage of an ABR versus a port? Like noise, vent is out of phase, better LF extension due to a sealed box, higher bass output, etc?
Hi Chuck. At bass frequencies the ABR effectively behaves as a port. It is not a closed box accoustically at bass frequencies, it is a Helmholtz resonator, just like a port.
One advantages it has is that for the purposes of midrange frequencies it is a closed box. This means that there is no midrange output from it. If you put a microphone (or your ear) near a port you will find that there is some midrange smear coming out of a port.
ABRs were very popular in the 70s, e.g. Kef Cadenza, Kef 104 AB, most large Celestion Ditton speakers. But they have fallen out of favour. Probably cost considerations played a part.
In theory ABRs are better controlled than ports.
The major disadvantage for me is that making one, ( though you can adapt an old drive unit) and particularly adjusting it are really difficult for diyers. A port is straightforward.
One advantages it has is that for the purposes of midrange frequencies it is a closed box. This means that there is no midrange output from it. If you put a microphone (or your ear) near a port you will find that there is some midrange smear coming out of a port.
ABRs were very popular in the 70s, e.g. Kef Cadenza, Kef 104 AB, most large Celestion Ditton speakers. But they have fallen out of favour. Probably cost considerations played a part.
In theory ABRs are better controlled than ports.
The major disadvantage for me is that making one, ( though you can adapt an old drive unit) and particularly adjusting it are really difficult for diyers. A port is straightforward.
Forgot to mention. The port works by the air in the tube vibrating. This can cause what is called chuffing, which is very descriptive of the noise that can emanate from a port, particularly if the diameter of the port is small. ABRs to not have this issue at all.