I'm in search of a decent 8" midbass driver. Needs to do mid-90s dB/2.83v and handle the 300 - 900 hz range with ease, preferably 4 ohm impedance.
The main issue I'm running into looking for a suitable driver is sufficient xmax along with efficiency. The driver will need to handle some decent power without turning into mush with loud transients. Obviously it will need to be some sort of pro audio driver given the application. Low distortion is a must.
Drivers like the Audax PR170MO don't have enough xmax to play louder without using steeper HP filter slopes. Levels I expect are 110 dB peaks in the specified range.
My other favorite B&C 8NDL51 isn't quite efficient enough and isn't available in 4 ohms. The 8PS21 has the same issue.
The 8PE21 is efficient enough as an 8 ohm driver, but not enough xmax to deal with a 300 hz 2nd order HP at higher output levels.
I've toyed around with the idea of using 2 drivers, but this will result in weird vertical dispersion issues.
Any suggestions?
The main issue I'm running into looking for a suitable driver is sufficient xmax along with efficiency. The driver will need to handle some decent power without turning into mush with loud transients. Obviously it will need to be some sort of pro audio driver given the application. Low distortion is a must.
Drivers like the Audax PR170MO don't have enough xmax to play louder without using steeper HP filter slopes. Levels I expect are 110 dB peaks in the specified range.
My other favorite B&C 8NDL51 isn't quite efficient enough and isn't available in 4 ohms. The 8PS21 has the same issue.
The 8PE21 is efficient enough as an 8 ohm driver, but not enough xmax to deal with a 300 hz 2nd order HP at higher output levels.
I've toyed around with the idea of using 2 drivers, but this will result in weird vertical dispersion issues.
Any suggestions?
If separation is to be at 300 Hz, then a lot of Xmax is not necessary at all.
I did a quick simulation of the Audax HM210Z10 in CB (Qtc 0.705), which has an Xmax of only +/- 1.5 mm:
crossovered at 300 Hz it is capable of about 118 dB/1m in half-space without exceeding its Xmax, which is really well above the desired 110 dB. 😎
Even a 1st order high pass would be enough for it not to exceed its Xmax below that.
Because of its high sound pressure level of about 97 dB/W/1m not much power is necessary.
Many greetings,
Michael
Translated with DeepL
I did a quick simulation of the Audax HM210Z10 in CB (Qtc 0.705), which has an Xmax of only +/- 1.5 mm:
crossovered at 300 Hz it is capable of about 118 dB/1m in half-space without exceeding its Xmax, which is really well above the desired 110 dB. 😎
Even a 1st order high pass would be enough for it not to exceed its Xmax below that.
Because of its high sound pressure level of about 97 dB/W/1m not much power is necessary.
Many greetings,
Michael
Translated with DeepL
Thanks Michael. I was looking at the HM210Z10 but was concerned about the Aerogel cone material holding up over time. I had good luck with aerogel drivers in lower spl hifi applications. I honestly prefer the sound of paper cones to most other materials, hence the mention of the PR170MO. Its a sweet sounding driver and sadly doesn't have the output capability down low, especially with a shallow HP.
I should have also mentioned the 110 dB number I gave was at about 10 - 15 ft distance, not 1 m. That tacks on several dB to the equation, likely closer to 120 dB. Thats a big asking from a small midbass running a 300 hz HP at a relatively shallow slope.
MM Bob, I gave the Beta 8A alot of consideration based on past experiences. The problem is I've received a few sloppy assembled examples (tilted and offset installed cones). Eminence didn't see this as sufficient reason to warranty them without any other obvious issues and shipping charges would have been further prohibitive.
While the Beta 8A is very capable of higher spls on paper, as dedicated midbass at extreme spl it tends to get rather shouty sounding. The xmax is speced at 3 mm based on the Eminence method of calculation, but in the real world (subtracting top plate thickness from VC length divided in half) its closer to 1.5 mm. On a few recent drivers I've observed some QC issues. Some of the VCs were installed offset in height. That will magnify THD at this small of an xmax in conjunction with higher power levels.
So that being said, the Beta 8A hasn't been the most accurately assembled driver, which is a shame. It would still be my first choice as a budget mid in smaller lower output settings, but my needs here are a bit more substantial.
I'd generally opt for horn loading for these expected output levels, but size constraints make it impractical. It needs to be a direct radiating setup.
I should have also mentioned the 110 dB number I gave was at about 10 - 15 ft distance, not 1 m. That tacks on several dB to the equation, likely closer to 120 dB. Thats a big asking from a small midbass running a 300 hz HP at a relatively shallow slope.
MM Bob, I gave the Beta 8A alot of consideration based on past experiences. The problem is I've received a few sloppy assembled examples (tilted and offset installed cones). Eminence didn't see this as sufficient reason to warranty them without any other obvious issues and shipping charges would have been further prohibitive.
While the Beta 8A is very capable of higher spls on paper, as dedicated midbass at extreme spl it tends to get rather shouty sounding. The xmax is speced at 3 mm based on the Eminence method of calculation, but in the real world (subtracting top plate thickness from VC length divided in half) its closer to 1.5 mm. On a few recent drivers I've observed some QC issues. Some of the VCs were installed offset in height. That will magnify THD at this small of an xmax in conjunction with higher power levels.
So that being said, the Beta 8A hasn't been the most accurately assembled driver, which is a shame. It would still be my first choice as a budget mid in smaller lower output settings, but my needs here are a bit more substantial.
I'd generally opt for horn loading for these expected output levels, but size constraints make it impractical. It needs to be a direct radiating setup.
If it has got enough sensitivity for you, and you don't mind the price consider the JBL 2119H, different recone kit from the 2118 with a better and more well behaved response.
8PE21 and Beta 8A was already mentioned.
Faital pro's new 8FE400 is looking good, released this year.
https://faitalpro.com/en/products/LF_Loudspeakers/product_details/index.php?id=401030110
Beymas 8MCxx are solid performers in terms of distortion and output.
USspeaker.com is the retailer that has got the largest selection in Beyma mids, including they're car audio drivers etc, not found on they're webpage.
The PHL 2460 is a well behaved and clean driver, quality is good, Klang & Ton has the full reviews in print:
http://lsv-achenbach.de/shop/product_info.php?cPath=196_221_713&products_id=327
18S 8NMB420 is a decent driver.
https://www.dibirama.altervista.org...nd-8nmb420-8-mid-woofer-8-8-ohm-400-wmax.html
Not sure about US availability, but something different from the normal choices, with decent pricing and design.
http://www.ad-audio.com/web/product/p2/8inch/
No experience, just another option.,
https://sica.it/prodotto/8-n-2-5-pl/
8PE21 and Beta 8A was already mentioned.
Faital pro's new 8FE400 is looking good, released this year.
https://faitalpro.com/en/products/LF_Loudspeakers/product_details/index.php?id=401030110
Beymas 8MCxx are solid performers in terms of distortion and output.
USspeaker.com is the retailer that has got the largest selection in Beyma mids, including they're car audio drivers etc, not found on they're webpage.
The PHL 2460 is a well behaved and clean driver, quality is good, Klang & Ton has the full reviews in print:
http://lsv-achenbach.de/shop/product_info.php?cPath=196_221_713&products_id=327
18S 8NMB420 is a decent driver.
https://www.dibirama.altervista.org...nd-8nmb420-8-mid-woofer-8-8-ohm-400-wmax.html
Not sure about US availability, but something different from the normal choices, with decent pricing and design.
http://www.ad-audio.com/web/product/p2/8inch/
No experience, just another option.,
https://sica.it/prodotto/8-n-2-5-pl/
Mmmm decent power handling. Is that 10watts, 50 watts,100watts. With more precise parMeters fellow diy can make improved recommendations and then you can make a more informed choice.good luck.
I must have missed it, but with that expectation of volume at 15ft., what room or listening space is going to handle that?
For a 8” MW to hit (7” estimated cone area) to hit 110dB for 300Hz @ 15ft = 123dB @ 1m
Needs about 4mm x-xmax
Reference:
Www.Baudline.com/Erik/bass/xmaxer.html
Needs about 4mm x-xmax
Reference:
Www.Baudline.com/Erik/bass/xmaxer.html
@Arez Thanks. I'll check out the FE400 and others you mentioned.
@Ixnay 110 dB peaks are typical in live rock drums and even guitar. A decent sized carpeted room has no issues with those levels. If you've ever heard the Chilipeppers B.S.S.M album, it begs to be played at proper eviction notice levels to get the full experience. Its a rock masterpiece and needs to be played back on a capable system to fully enjoy. The drums are recorded impeccably on vintage analog gear.
@Ixnay 110 dB peaks are typical in live rock drums and even guitar. A decent sized carpeted room has no issues with those levels. If you've ever heard the Chilipeppers B.S.S.M album, it begs to be played at proper eviction notice levels to get the full experience. Its a rock masterpiece and needs to be played back on a capable system to fully enjoy. The drums are recorded impeccably on vintage analog gear.
Ya'll lost me here: 110 dB @ 15'/3.28084' = 110 dB/4.572 m, so assuming a 90 dB/m eff. driver we need +20 dB = 10^(20/10) = ~100 W/4.572 m
Beyma 8WRS300 or 8WR300 maybe. But for that kind of volume most use bigger drivers, like 10 to 15" drivers. Demanding that kind of volume from a single 8" in that range is maybe not realistic.
Thats a steal. You can't buy a better driver for the money and intended use.
It has to be a driver small enough to play up to 800 - 900 hz and do well off axis, yet have enough xmax and headroom.
I've looked at the Beyma mid drivers and they may be an option. Ciare makes some too but I'm skeptical of their QC.
The B&C 8NDL64 has a larger VC, smooth FR and higher efficiency with good xmax. The impedance curve has some significant wiggles in it which may indicate potential resonance problems.
I've looked at the Beyma mid drivers and they may be an option. Ciare makes some too but I'm skeptical of their QC.
The B&C 8NDL64 has a larger VC, smooth FR and higher efficiency with good xmax. The impedance curve has some significant wiggles in it which may indicate potential resonance problems.
Attachments
Yes, I've alluded to that above as well:
However, I must have misunderstood the first post here and @profiguy does not need 110dB/1m, but 110dB/10-15ft (so between 3 and 4.5 m). That would be, as someone has already shown above, almost 124 dB/1m. 😳
This would require almost 500 watts even for such a high efficiency driver as the Audax I mentioned, which its voice coil would not be able to handle in a lifetime. However, the stroke at 300 Hz would still be less than +/- 2 mm.
So stroke is not an issue, but power handling is. If it's going to be that extreme, I'd go to either 2 x 8 inches or 1 x 10 inches, , looking around among the midrange rockets. 🙂
(I hope this is understandable, I'm using a translation program (deepl.com)).
Many greetings,
Michael
Translated with DeepL
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Here’s is a few options:
http://www.loudspeakerdatabase.com/...9.0/100_pw_10000/94.0_spl_111.8/4.0_xmax_42.5
There are probably more than that; some suitable candidates not on that list. Usual suspects include B&C, Eminence, PHL
You will need to model the driver in cabinet and baffle, which determines the baffle step loss, which always determines the low end response around 300Hz. And then figure out what voltage drive you need to reach your desired SPL.
Remember power handling is usually 100 hour test or long-term test whereas music content is all about dynamics.
http://www.loudspeakerdatabase.com/...9.0/100_pw_10000/94.0_spl_111.8/4.0_xmax_42.5
There are probably more than that; some suitable candidates not on that list. Usual suspects include B&C, Eminence, PHL
You will need to model the driver in cabinet and baffle, which determines the baffle step loss, which always determines the low end response around 300Hz. And then figure out what voltage drive you need to reach your desired SPL.
Remember power handling is usually 100 hour test or long-term test whereas music content is all about dynamics.
I hate all this 'science'. However, there is also the possibility of an elephant in the room, AKA, in the enthusiasm to perform calculations - you forgot to hook-up the doll!
This is not a sub. Subsequently, stereo output is assumed, inside a room. Ergo, there are TWO drivers involved (+3db). Power handling requirements are halved.