One Larger DML Panel vs Two Smaller Panels (...vs One Smaller Panel)
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- Опубліковано 21 сер 2024
- 3D Printed DML build parts: www.typicalben....
Despite being very happy with how my last build went, I'm feeling the itch again and am about to start a new hybrid DML speaker build.
The design I've come up with depends on having 2 panels per chanel. It's not about sound quality - it's about packaging. Anyway, it would suit me just fine if I can get compatible sound out of 2 small panels vs the 1 larger sized panel I've used before, so that's what I'm testing today.
- All panels are 2mm acrylic.
- All panels have 40w exciters (a mix of the thruster and the steered flux models from Dayton, but my previous testing has shown fairly minimal differences in response between these two).
- No EQ or other signal processing was used and tone controls were bypassed on the amp.
- Measurements taken and analysed in REW :
www.google.com...
UPDATE: It looks like the measurement issues came from a bad soundcard calibration file. I have re-calibrated the soundcard in REW and subsequent measurements look much better, particularly in the HF. I won't mess with this video as there are no real changes in the lower frequencies I'm discussing here.
I'm really glad I ran across your channel. I've been thinking about making the foam version of these speakers ever since I first watched the Tech Ingredients video that kind of started it all off. I like your approach to a Hybrid speaker and I'm going to watch each of your videos to learn more. I also had an idea to use one of these for a guitar amp speaker, and you've already done that! Thanks for the great content!
Hey James, thanks a lot. I do like the idea of a single full range panel but talking within the constraints (materials, cost etc) I do think that the hybrid approach is the way to go - I'd say most DML people are probably at least using a subwoofer at the very low end and I'm really just extending that upwards a bit to take more load off the panels (~250hz instead of ~100hz for example), then building it into a single unit.
Right now I'm working on new hybrid-style speakers for my TV room but when they're done I'm keen to do a guitar amp v2 as well (a full amp this time rather than just a panel + external amp).
I'm a former cellist, and have often wondered about making panels which replicate the soundboard (top) of a cello or even a double bass. Locating the exciter the way one would place a bridge, and using a "bass bar" like violin family instruments do to ensure the vibrations get the full plate moving.
Informative and practical! Good job!
Ben, your no sound measurement has me wondering a bit. If you can't hear it, then it's probable that your mic can't hear it either. I had an issue with REW a while back where the measurements were just unbelievable, not at all what I know I was hearing with my ears. So I uninstalled then updated REW to it's latest version and I was instantly rewarded. I think I was gating something somewhere, just playing around and forgot to reset my settings. I'm sure I caused the initial problem but forgot what I did to cause it. There is no master "reset" that I'm aware of aside from uninstall/reinstall. But I'm thinking you may be having a similar problem like I had.
On the flip side, this could also be an issue with your mic, preamp and/or calibration file, OR the measurements might be perfectly correct and you just can't hear it. I suspect something weird is happening somewhere in your set up, because you should definitely hear the highs running away like that. These things would be "very" hard to listen to for any length of time if this is how they truly measure up top. Your ears would be bleeding! Anyway, that's my nickles worth.
Cheers 🍻
Ran into the same issue myself. I was getting inaccurate readings for over a year until I deleted REW and reinstalled latest version.
@@Masterdebator881:
Were you playing around with REW by tweaking measurements or did it happen with all things kept as default? Yeah, it took me about a year to know something was definitely wrong too. I wasted soooo much time until I realized the problem wasn't me. Cheers 🍻
Thanks for this suggestion, I’ll try a fresh installation today and run a few sweeps. It would be a good result if it’s just software related!
It seems this was an issue with my soundcard calibration file in REW. Your comment got me thinking more about software which led me to run the recalibration and the subsequent measurements look a lot more realistic/natural.
@@TypicalBenYT:
Any one of us that has been in the trenches, yeah, we've been there!
Cheers 🍻
Hi. I’m considering building some panels. It’s interesting that folks aren’t using (in addition to the subwoofer) three or more different sized circular panels. I’d cut all different sizes and a couple of different drivers, then mix and match to the room. Change rooms or decor? Just see which sizes work best with the new acoustics
Fantastic video again. Did the coupling effect change after new calibration? Do you plan to take measurements of 2 large panels in a similar stereo setup? That comparison could be interesting too. Thank you!
Thank you! The effect didn't change - just the overall slope of the measurement is different. I've posted the updated versions here: imgur.com/a/s0F6Rh9
And on the second point - yes I'd like to test this out more on different panel sizes (and shapes) - I just have a lot on at the moment so couldn't go too deep into it right now.
Might I suggest trying an HPF and LPF on your lower panel, and bringing it in just where you need it? Otherwise I can see an issue with the two sources phasing a bit. Common trick with most multi driver speakers with two of the same drivers.
I would add 2 exciters to the big panel I've added 2 exciters to a 2x3ft polystyrene foam panel wrapped in fabric and the midrange is more pronounced makes the single exciter panel sound like 💩
Which model exciters are you running on those?
@Typical Ben dayton DAEX25
I got 2 panels so in total 4 exciters running in 8ohms on to 1 channel of my amp
Thanks for all your videos on the subject! Do you have any experience running different panel materials on the same channel? My first toe dip in DML is looking to be a 2’x2’ pink board with 1x 24w exciter (8ohm) in parallel with a 2’x4’ acoustic ceiling tile with 2x 4ohm exciters in series. This all going in the garage so looks don’t matter. Also got a dedicated 8ohm tweeter and passive high/low pass filters centered around 6khz to play around with too. I don’t have a dsp, but the fosi amp has a treble dial. Sub is preamp and has a variable crossover too. Hope it doesn’t end up like a Jr High band practice :)
No problem, glad your finding them useful! I haven't done anything with multiple-materials but one thing I haven't seen addressed is that different panel types will have different efficiencies eg the foam board might be a few db louder than the tile, in which case the combination might not be as effective as you'd want for evening out frequency response. I guess my view is that I'd rather get a decent sound with a single material and stick with it but that it could work out great as well. There isn't a whole lot of detailed info out there so the best thing to do is just give it a go and see how it sounds!
hello ,
First of all, congratulations on your study about exciter!
I want to install some exciters in the mirror of my house...
Can you recommend me the best?
thank you so much
Hi there and thank you! I have mostly used the Dayton audio exciters. If you just need ambient music I’d recommend the daex25fhe-4.
Can this REW software do spectrum analysis on a white-noise burst, instead of a sweep?
Asking because, by doing so you could avoid reflections from within the room (if you keep your burst short)
Interesting question I will have to look into that.
Do you still rec clamped plexi panels over free-hanging foamboard type panels?
I really like the acrylic because it's a good combination of sound quality and aesthetics (don't think my wife would enjoy a pair of big pink foam panels in our living room and come to think of it, either would I).
The only downside with the way I'm doing it is efficiency - you need a bit more power (which is why I tend to be using larger exciters) to push these panels but it's nothing crazy.
what HAPPENED????
all o sudden no more vids
yikes!
Have had a lot going on in the last 6 months or so. I've started building a new DML based system so I'm hoping to start getting vids out this month :)
Why do you metric people use thousands when you can use hundreds in your talk? For instance isn't 600 by 400 mm the same as 60cm by 40com? I mean you're talking broad numbers no need to get into the thousands. Why do you do that? It's far easier for us no-M'ers to follow along; no?
Hahaha, it's all Greek to me, I can't visualize it regardless. I wish everything was metric everywhere, it always made more sense to me vs the inch and the dreaded fraction thereof here in the U.S. But at least I can picture an inch, I know how big/small it is. About 25 mm. It don't matter CM or MM or KM, I still have to convert it to something I know. Cheers 🍻
Yeah using millimeters is standard for anything construction related, buying timber etc. Now that you mention it I notice I did flip flop between millimeters and centimetres in this video which is a bit silly.
I think I find, as one of the metric people, that using millimeters is just much easier. Something that would be 5.8cm would be 58mm. This might not make too much difference when writing it down but when its conveyed verbally saying "five point eight centimeters" would be relayed as "fifty eight mill".
Firstly, it indicates a degree of precision. i.e. being within a millimetre not a centimetre. We do this for anything of medium precision, by working to the millimetre. Higher precision factors are also given with tolerances when required.
Secondly, it's easy. The whole point of the metric system is to have easily convertible units everything is just a factor of ten, so add or remove a 0 or a decimal place. For instance, how many half inches in a mile? That's a minute of work. Alternatively, how many 5mms in a km? = X2 X100 X 1000 200,000 = easy.