Apologies in advance for starting what is more or less one of those "what is the best..." threads, but...
I'm looking for candidates to be used in the woofer section of a dipole speaker I will build, with the emphasis on low distortion. This will not be used in the lowest band in the system, and covers about 80Hz-500Hz. I am looking for either a 15" or 18" driver, preferably with an open frame. If possible, I would prefer a single pole vent over the multiple smaller motor vents that cause turbulence and noise. Since the motor is "out in the open" the noise can't be suppressed easily. Because of the 80Hz cutoff, I don't need high Xmax and high Qts isn't required either. I would prefer to have high sensitivity, e.g. 95dB/W or greater, and an 8 Ohm nominal driver for ease of driving it and bridging an amp into the load if necessary. Since the band should go up to around 500Hz, low inductance is important, and this is another knock on specialized "subwoofer" type drivers. Finally, I need to be able to purchase the driver from a US distributor, and this eliminates some EU/AUS brands.
This rules out some candidates. For example, I would consider the AE Speakers dipole or IBHT lines of drivers, but they are more along the "subwoofer" line with very low Fs, higher Xmax, and lower sensitivity.
I have been using the Eminence Deltalite 2515 and it seems to meet these requirements. It's also very affordable.
Another candidate I am interested in are the JBL 2268H/2268HPL 18" woofers. There is a JBL tech note showing very low distortion operation above 50Hz at 115dB SPL (not sure in what kind of enclosure, etc.) and the frame is relatively open. It seems very promising.
What other drivers should I be considering?
I'm looking for candidates to be used in the woofer section of a dipole speaker I will build, with the emphasis on low distortion. This will not be used in the lowest band in the system, and covers about 80Hz-500Hz. I am looking for either a 15" or 18" driver, preferably with an open frame. If possible, I would prefer a single pole vent over the multiple smaller motor vents that cause turbulence and noise. Since the motor is "out in the open" the noise can't be suppressed easily. Because of the 80Hz cutoff, I don't need high Xmax and high Qts isn't required either. I would prefer to have high sensitivity, e.g. 95dB/W or greater, and an 8 Ohm nominal driver for ease of driving it and bridging an amp into the load if necessary. Since the band should go up to around 500Hz, low inductance is important, and this is another knock on specialized "subwoofer" type drivers. Finally, I need to be able to purchase the driver from a US distributor, and this eliminates some EU/AUS brands.
This rules out some candidates. For example, I would consider the AE Speakers dipole or IBHT lines of drivers, but they are more along the "subwoofer" line with very low Fs, higher Xmax, and lower sensitivity.
I have been using the Eminence Deltalite 2515 and it seems to meet these requirements. It's also very affordable.
Another candidate I am interested in are the JBL 2268H/2268HPL 18" woofers. There is a JBL tech note showing very low distortion operation above 50Hz at 115dB SPL (not sure in what kind of enclosure, etc.) and the frame is relatively open. It seems very promising.
What other drivers should I be considering?
2268 also *looks cool*. Since you can see the rear of the driver in an OB, that is not a band thing.
There is also the new line from SB Audience. For example the Rosso-18SW650:
SB Audience Rosso-18SW650 18" Subwoofer
But I have not seen any measurements on that drivers and others like it in the lineup.
There is also the new line from SB Audience. For example the Rosso-18SW650:
SB Audience Rosso-18SW650 18" Subwoofer
But I have not seen any measurements on that drivers and others like it in the lineup.
The AE TD15M looks like it would be a better fit for your criteria. Higher efficiency, lower Xmax, and lower Qts than the IB or dipole drivers and claimed response up to 2k. Nice open frame, too.
Hmmm, I forgot about the TD driver line. Interesting. But I found some measurements posted on this YouTube video that place it below the JBL drivers in terms of distortion performance. Attached plot is from the video, supposedly for 92dB@1m SPL, which isn't all that high.
Do you know of another source of distortion data/info on the TD15M?
Do you know of another source of distortion data/info on the TD15M?
Attachments
It's hard to say which drivers will be quiet in free air. The B&C 18PS76 is nice and quiet despite having small under spider vents. The BMS woofers have more noise. Kappalite 15HO/LF are a little louder than the B&C but not by much.
SB Audience looks good. Would be nice to have a demodulating ring in the motor.
The AE woofers look good but they have air noise according to Data-Bass. Ricci also said his 15M's surround tightens up around 3mm.
SB Audience looks good. Would be nice to have a demodulating ring in the motor.
The AE woofers look good but they have air noise according to Data-Bass. Ricci also said his 15M's surround tightens up around 3mm.
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The TD18H with a dustcap and foam around the under spider vents would be about as good as it gets.
I found the full datasheet for the 2216Nd posted here. All in all, that looks pretty amazing, but the harmonic distortion performance seems similar to the 2268 (neither of which are bad by any stretch of the imagination!). See attached HD plot for the 2268.
2268 is $322 and 2216Nd $599 at The Speaker Exchange. Not seeing how the higher cost would be worth it.
2268 is $322 and 2216Nd $599 at The Speaker Exchange. Not seeing how the higher cost would be worth it.
Attachments
I've never seen DHT measurement of it, but i know the Faital 15PR400 is used by a guy i know that is rather anal on distortion for his speakers. He uses them for bigger setups as midbass speakers in a 4 way configuration in expensive HT theaters he builds for rich people... He uses them from 90hz to about 750Hz i think.
The Faital Pro drivers are really good from my experience. Also using them for mid-bass, can easily go down to 50-60 with no distortion. They are a bit pricey though
You have to step up the size/cost to have noticeable improvement over the Deltalite in this scenario. Most quality prosound drivers are highly competitive and offer similar performance.
Never heard this one, but I like the low Fs and high Qm.. maybe you can hear it somewhere.
LOUDSPEAKER 18WRS600 8 OH
LOUDSPEAKER 18WRS600 8 OH
I thought this might be of interest, although 10" drivers are compared.
Personally, I use the Faital Pro 15PR400-8 as a mid bass in one of my OB designs.
A positive thumbs up on that one.
Battle of the 10" monster Midbasses -
Techtalk Speaker Building, Audio, Video Discussion Forum
C.M
Personally, I use the Faital Pro 15PR400-8 as a mid bass in one of my OB designs.
A positive thumbs up on that one.
Battle of the 10" monster Midbasses -
Techtalk Speaker Building, Audio, Video Discussion Forum
C.M
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Well, since you mentioned it, there is this monster that was recently offered for sale by SB Audience:
SB Audience :: ROSSO-21SW800
This is a 21" driver with high efficiency and with bass extension that seems perfect for OB systems. Getting it to play nice up to 500Hz might be possible, since Le is not high, but a cone breakup mode might already be happening by 300Hz. It's not yet available in USA at Madisound (maybe via special order?). Seems to cost about 400 Euros across the pond.
Here is the response plot:
Looks pretty clean.
I recall a thread where someone used a 24" Precision Devices crossed to a 2" full-range on a JBL horn @ 400hz. No baffle.
Seemed to work pretty well considering it was used as a two-way system.
I recall a thread where someone used a 24" Precision Devices crossed to a 2" full-range on a JBL horn @ 400hz. No baffle.
Seemed to work pretty well considering it was used as a two-way system.
UPDATE:
I ended up buying a pair of the JBL 2268HPL, since they seem to be relatively affordable all things considered. Wow, they are indeed low distortion just like the whitepaper on the motor design describes. This is especially true in the 80-100Hz region. It's a really great driver for my application, except for one thing: size.
I will be using these drivers in a nude open baffle system. I currently have a version of these speakers with the Eminence Deltalite 2515 serving in the woofer role. It is not as good as the 2268 but it is better than other pro drivers I have measured in terms of distortion at 100Hz when deployed as a nude woofer.
It would be nice to find a different 15" or even 12" driver that was on the level of the 2268. The 18" form factor is a little, um, big and a 12 or 15 makes the speaker visually smaller overall. I don't need a subwoofer and Xmax requirements are not high. Among AE's offerings, the Dipole 12, Dipole 15, TD12M and TD15M have rather off putting high price tags and not quite ideal TS parameters for my application. For example, I could get two Faital 15PR400 for about the cost of one TD15M. When a driver of interest costs $100 and under I will probably just buy a pair to check them out. But now I have a gaggle of these "almost good enough" drivers lying around! I have heard good things about some drivers from Precision Devices but only rumors.
Any driver under consideration must operate cleanly up to 500Hz. This rules out anything larger than an 18". Dedicated subwoofer drivers with high Xmax tend to crap out earlier. I do not need much excursion capability (3-4mm is enough) nor high Qts as long as Fs is 40Hz or lower and sensitivity is high (96dB/W or higher). I would prefer an 8 Ohm driver. These criteria eliminate most every home audio 12" woofer. I have considered using four 8" class woofers wired in series-parallel and I have some in hand that I will try out like this to see what happens.
Great as it is, the 2268 is not a "normal" driver that will be generally available to DIYers. Are there any other 12" or 15" low distortion drivers I should be looking at? Anything else I should consider?
I ended up buying a pair of the JBL 2268HPL, since they seem to be relatively affordable all things considered. Wow, they are indeed low distortion just like the whitepaper on the motor design describes. This is especially true in the 80-100Hz region. It's a really great driver for my application, except for one thing: size.
I will be using these drivers in a nude open baffle system. I currently have a version of these speakers with the Eminence Deltalite 2515 serving in the woofer role. It is not as good as the 2268 but it is better than other pro drivers I have measured in terms of distortion at 100Hz when deployed as a nude woofer.
It would be nice to find a different 15" or even 12" driver that was on the level of the 2268. The 18" form factor is a little, um, big and a 12 or 15 makes the speaker visually smaller overall. I don't need a subwoofer and Xmax requirements are not high. Among AE's offerings, the Dipole 12, Dipole 15, TD12M and TD15M have rather off putting high price tags and not quite ideal TS parameters for my application. For example, I could get two Faital 15PR400 for about the cost of one TD15M. When a driver of interest costs $100 and under I will probably just buy a pair to check them out. But now I have a gaggle of these "almost good enough" drivers lying around! I have heard good things about some drivers from Precision Devices but only rumors.
Any driver under consideration must operate cleanly up to 500Hz. This rules out anything larger than an 18". Dedicated subwoofer drivers with high Xmax tend to crap out earlier. I do not need much excursion capability (3-4mm is enough) nor high Qts as long as Fs is 40Hz or lower and sensitivity is high (96dB/W or higher). I would prefer an 8 Ohm driver. These criteria eliminate most every home audio 12" woofer. I have considered using four 8" class woofers wired in series-parallel and I have some in hand that I will try out like this to see what happens.
Great as it is, the 2268 is not a "normal" driver that will be generally available to DIYers. Are there any other 12" or 15" low distortion drivers I should be looking at? Anything else I should consider?
Since your mentioning Acoustic Elegance, Dipole and TD drivers and Open baffle use.
What about the LO(Lynn Olson) 15? Higher fs and lower qts then the Dipole series, with more sensitivity (94,5 db on paralelled 16 ohm coils), shorter 9mm xmax and lighter cones etc et. Sounds like it would be the closest choice from they're selection,
Dont quote mee on this but if memory serves me right the Cone and surround is the same as the TD15M.
I also saw you were looking for other sources of distortion measurements earlier in the post, Brandons page got measurements from AE TD12M,15X,LO15 and IB15, along with several pro driver mfgs:
AE Speakers LO15 4ohm - drivervault
As for JBL Drivers this list is quite useful:
https://help.harmanpro.com/thiele-small-low-frequency-driver-parameters-and-definitions-(2)
And Audioheritage.com got a lot of JBL driver discussions and spec sheets.
Eighteensound makes good quality woofers too in a large selection.
Beyma, B&C and BMS are also all easily available in the US.
Anyways the 2268H is a nice woofer, so enjoy 🙂
What about the LO(Lynn Olson) 15? Higher fs and lower qts then the Dipole series, with more sensitivity (94,5 db on paralelled 16 ohm coils), shorter 9mm xmax and lighter cones etc et. Sounds like it would be the closest choice from they're selection,
Dont quote mee on this but if memory serves me right the Cone and surround is the same as the TD15M.
I also saw you were looking for other sources of distortion measurements earlier in the post, Brandons page got measurements from AE TD12M,15X,LO15 and IB15, along with several pro driver mfgs:
AE Speakers LO15 4ohm - drivervault
As for JBL Drivers this list is quite useful:
https://help.harmanpro.com/thiele-small-low-frequency-driver-parameters-and-definitions-(2)
And Audioheritage.com got a lot of JBL driver discussions and spec sheets.
Eighteensound makes good quality woofers too in a large selection.
Beyma, B&C and BMS are also all easily available in the US.
Anyways the 2268H is a nice woofer, so enjoy 🙂
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Arez: thanks for the comments and the link to the AE driver data at DriverVault. I will give these drivers a closer look.
Here is another candidate: the Precision Devices PD.153C01
PD.153C01 | Precision Devices Loudspeakers
I have seen it touted as a "very low distortion" driver. It fits the bill in many other ways. Has anyone out there tried one yet?
Here is another candidate: the Precision Devices PD.153C01
PD.153C01 | Precision Devices Loudspeakers
I have seen it touted as a "very low distortion" driver. It fits the bill in many other ways. Has anyone out there tried one yet?