I bought a few of the $7 US HiWave HiBM65C20F-8 BMR wide range drivers. At the price, I could not resist. Initial impression is that they sound good, and it's hard to tell if one is off or on axis as it sounds about the same wherever you stand.
Here is the test cabinet (1.6 liter and well stuffed):
And, the measurement (close mic about 6", all other speakers, such as the subwoofer, are disabled for the measurement):
Just using one for a center channel for now. I'll listen for a while (a month or two) and then put a real front baffle on (right now the baffle is 1/4" thick cardboard). I'm currently playing music through it (mono - 😀 ).
Here is the test cabinet (1.6 liter and well stuffed):
And, the measurement (close mic about 6", all other speakers, such as the subwoofer, are disabled for the measurement):
Just using one for a center channel for now. I'll listen for a while (a month or two) and then put a real front baffle on (right now the baffle is 1/4" thick cardboard). I'm currently playing music through it (mono - 😀 ).
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Can you say line array?
😀
What do you think of that dip? Must be some phase issue.
There is a big spike in the impedance chart.
Can you post a raw measurement?
Maybe HD as well?
That would be splendid!
😀
What do you think of that dip? Must be some phase issue.
There is a big spike in the impedance chart.
Can you post a raw measurement?
Maybe HD as well?
That would be splendid!
I think there is not as much 'air' as some of the more expensive full range drivers (such as Fountek FR88EX, admittedly six times the price). Although I'm not sure too many people would be missing much above 12K anyway due to hearing issues. We shall see with higher levels and some break in. The HiWave has more bass than expected in a tiny sealed cab and will interface well with a subwoofer at 100 Hz. It's fast at all frequencies and upper bass is very tuneful....
No smoothing, with phase:
This is an in-room measurement and I have a lot of computers with fans running. The room has poor acoustics, but I did close mic it to help with that. Just thought you might want to know.
This is an in-room measurement and I have a lot of computers with fans running. The room has poor acoustics, but I did close mic it to help with that. Just thought you might want to know.
Can u hear that dip? Somebody in another thread said they could but, it looks to be a pretty narrow BW to me.
No way. 🙂 I'd have to be incredibly familiar with a specific recording and there would have to be some important sonic detail right at that frequency. Then maybe a real human could pick out that that specific detail sounded 'muffled' or some such. I guess I just don't listen to specific tracks over and over like the professional reviewers do. 🙂
No, that dip is a phase issue due to a sort of mechanical crossover I'm guessing.
It must be some sort of transition from piston behavior to oscillatory behavior.
It must be some sort of transition from piston behavior to oscillatory behavior.
(Very) roughly calculating from the manufacturer's data, it's in the ballpark for transition frequency, and also possible reflections from the front roll-surround.
Not sure I like the 20% +/- Fs variation, since that could put a pair of drivers at anything up to 34.4Hz apart in resonant frequency, although given the price, can't really complain. 😉
At 81dB/W/m, I would think so!
But still, it's something to ponder for a cheap, effective surround speaker. I'm thinking a composite decking post with one of these on top, and maybe four Aura NS3's (unless there's a longer-throw 3"-4" driver of which I'm unaware) in series-parallel on the floor.
Here's a THD measurement at 1K. Let me know soon if you want to see any other frequencies. Note that everything below 1K is just the high room noise floor.
I listened to a few TV shows on the HiWave center channel today and found that, even with the center set to +8 dB in the receiver, the dialog was low compared to the music emitting from my reference speakers. I upped it to the max (+10 dB) and will try again.
The intelligibility was good, just not loud enough relative to the mains (which are not particularly efficient mind you). Sounded recessed, for lack of a better word.
I'm sure a line array of the BMR's would fix that but I only bought three, not the required four for a series/parallel wiring scheme. No big deal, will see how it goes.
Also, if the BMR was used (even in singles) for the front three, that would probably work as well as then all three would have the same power requirements.
Even though it only takes an hour apiece to build these in temporary form I'm debating if it is worth further experimentation or not. 😀
Regardless, it has to be one of the best $10 speakers out there.
The intelligibility was good, just not loud enough relative to the mains (which are not particularly efficient mind you). Sounded recessed, for lack of a better word.
I'm sure a line array of the BMR's would fix that but I only bought three, not the required four for a series/parallel wiring scheme. No big deal, will see how it goes.
Also, if the BMR was used (even in singles) for the front three, that would probably work as well as then all three would have the same power requirements.
Even though it only takes an hour apiece to build these in temporary form I'm debating if it is worth further experimentation or not. 😀
Regardless, it has to be one of the best $10 speakers out there.
How about this.....
Do a 1.5 way.
Wire 2 in series for a N impedance of 16 ohms, then put a cap on them where they fall in frequency.
Do a 1.5 way.
Wire 2 in series for a N impedance of 16 ohms, then put a cap on them where they fall in frequency.
I bought a pair of these as well, I couldn't resist.
The dips are audible with a swept sine but not with music IMO.
The way I understand it, the biggest dip at 1.8k as well as the stepped response in the upper end is a result of the bending mode radiator technology. I can't remember where but I read about them not too long ago in a book. I think the technology trades an even response for wide dispersion and can provide decent LF if designed for it. I'll see if I can find the info.
-Matt
The dips are audible with a swept sine but not with music IMO.
The way I understand it, the biggest dip at 1.8k as well as the stepped response in the upper end is a result of the bending mode radiator technology. I can't remember where but I read about them not too long ago in a book. I think the technology trades an even response for wide dispersion and can provide decent LF if designed for it. I'll see if I can find the info.
-Matt
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