Hello.
I'm looking for the top midrange drivers for open baffle, to be used approx 400 to 3000 Hz in an active system.
I am now using B&C 8PE21 and considering Radian LM10n plannar. I like AMT tweeters - using Beyma TPL-150H open back now.
The Purifi 6.5" midrange looks appealing too, but haven't seen comments about them for OB.
What are the better OB mids out there, for this range?
Thanks in advance!
I'm looking for the top midrange drivers for open baffle, to be used approx 400 to 3000 Hz in an active system.
I am now using B&C 8PE21 and considering Radian LM10n plannar. I like AMT tweeters - using Beyma TPL-150H open back now.
The Purifi 6.5" midrange looks appealing too, but haven't seen comments about them for OB.
What are the better OB mids out there, for this range?
Thanks in advance!
I tested nearly a dozen drivers for a nude dipole many years back and the best of the bunch in that frequency range was the BMS 6N160. It has good sensitivity, low distortion and the front side and back side output match well, which wasn't the case with many of the drivers.
IIRC
@CharlieLaub found that the SB17MFC was a good candidate.
I found the PTT6.5M04 a good candidate.
@CharlieLaub found that the SB17MFC was a good candidate.
I found the PTT6.5M04 a good candidate.
Just to add a bit of fuel to the fire, I am sure you are aware but with a 3 kHz crossover you are going to have a dip in power response between the mid and the tweeter, especially given the sizes of mid you are looking to use. Might be just fine for you...
Thank you!
Will look into this one.
Did you happen to test any of the large plannars among that dozen of drivers you tested? In case you didn't, why weren't they included?
I'm probably going to xo at 2kHz, but asked up to 3kHz to have a little wiggle room.
But I am not aware of the power dip at 3kHz. Where can I read more about this?
I'd suggest checking out ER audio 505 kit as an interesting alternative to the RADIAN.
https://www.eraudio.com.au/index.php?option=com_content&view=article&id=5&Itemid=116
https://www.eraudio.com.au/index.php?option=com_content&view=article&id=5&Itemid=116
Not specifically at 3 kHz, but just that as your center-to-center spacing increases, you get more lobing (off-axis dips) and less uniform power response
Play around with driver spacing and crossover freqs in VituixCAD and you’ll see
Thank you.
I wasn't aware of these. I recall you purchased LM10n. How did you like them?
Have you had good references about ER 505? I went through their website, read all customer examples shown. All seemed to use middle of the road electronics and used that huge panel for mids and tweeter. Makes me wonder.
I use Purifi PTT6.5M for midrange in open baffle. But as great as this driver is, it should not be crossed higher than 2000 Hz, since their front and back waves start to be different at around 1800 Hz. Luckily I have a good AMT for tweeter and also use the current drive amplifier to drive it, so 1800 Hz LR4 crossover is durable, though not as perfect as I want.
Hello,
400-3000Hz ? a 5" will do a better job rather a 6" ? A ptt5.25 or ptt4.0 or a 5n160 etc. plenty of choices
Best OB mid ? depend on its integration with the low mid and tweeter. I think the big challenge is this integrate seamless the midrange.
400-3000Hz ? a 5" will do a better job rather a 6" ? A ptt5.25 or ptt4.0 or a 5n160 etc. plenty of choices
Best OB mid ? depend on its integration with the low mid and tweeter. I think the big challenge is this integrate seamless the midrange.
Yes, in my measurements both of these were excellent as a nude dipole midrange. These both have similar response to the rear as to the front, up to about 1.5k to 2k. The SB17MFC had usable response all the way up to breakup (around 4-5kHz, which was very unique and allows a bit higher crossover point to the tweeter while retaining a good pattern both in front and in rear.
Putting them in even a small/narrow baffle will change the response compared to when nude, so always measure on a test piece that simulated your planned baffle before committing to the final baffle size/shape. Make sure to measure at multiple angles in the horizontal plane, out to about 60 degrees, both in front and to the rear, and you will quickly see how these drivers compare to other drivers that just do not work well nude or OB. The exact angle is not critical, but measuring more than just the on-axis response is critical.
I don't think this a unique situation. Here it is on large 2pi "infinite" baffle:
courtesy: @bikinpunk
Reference:
https://www.erinsaudiocorner.com/driveunits/purifi_ptt6.5m-08-nfa-01a/
Based on this, I'd crossover somewhere around 2KHz.
What's a few hundred hertz between friends?
With TPL-150 I had good results with the SB nero 6mrn150 (or audax pr17 and phl1120), if I remember crossed around 1600-1800Hz.
Of course it depends how low the midrange will have to go, but if you cut at 400Hz they seem a very good option, so lively.
Now the Kartesian mid120 was also great, but a better match with the tpl-75, good up to 2.5Khz in nude dipole, very symmetric response, and very detailed.
Of course it depends how low the midrange will have to go, but if you cut at 400Hz they seem a very good option, so lively.
Now the Kartesian mid120 was also great, but a better match with the tpl-75, good up to 2.5Khz in nude dipole, very symmetric response, and very detailed.
@tktran303 : Yes, we agree that it is absolutely normal phenomenon, and 1800 or 2000 Hz is not a big deals. But I am kind of perfectionist 😉, so 1800 Hz is better for me in terms of frequency response, both for front/ back waves similarity and midrange/tweeter matching. Of course, the trade off is higher distortion due to the higher load the tweeter must drive, but I am fine with it.