Lii Audio 15" full range

I've been listening to mine all afternoon. without added 15 inch woofer for me in this open baffle config it wouldn't be usable at all not even close (the size of the baffle is tiny) but with one 15 inch woofer crossed over at 100hz it is already very good. I like this so much, i would consider making a passive crossover at 100hz which would also address the extreme SPL disparity between the F-15 and the eminance alpha 15 woofer but making the required measurements in my very awful (in terms of acoustics having large windows all around) living room with me having zero spare time working on my PHD thesis is a fool's errand so what i did is this:

I put a passive volume controller between the preamp and the power amp that goes to the F-15s and used it to dial down the output level of the F-15 by almost %50. I did this just by ear and tried to make the sound AS BALANCED AS i can and compared to various commercial speakers that I have around as a sanity check. I also prefer a darker and warmer tonal balance so then I did some fine adjustments to tailor the sound to my liking. Now when i adjust the volume with my preamp the sound is coherent enough to be very usable from very low SPL levels to very high.I didnt even use any DSP or stand alone crossover. my Emotiva preamp has built in crossover for subwoofer integration. I used that. now the F-15 are crossed over above 100hz and the A15 woofers at below 100hz.

this is a project half way done but im gonna call it a day use the speakers like that just tuned by ear. i will make no measurements or attempt any objective evaluation. maybe after i defend my thesis but for now this is about as far as I'll take this. thanks to everyone who helped.I couldnt have done it without the great advice and guidance that i got here.
 
Last edited:
I put the miniDSP back together keeping the Nichicon FG caps at the 4 outputs and putting the 47u, 100V caps back at the input. I tried it with the headphone output as source from the Aune and it still barely holds a candle to the Aune alone. Now it seems the sound stage is flattened vertically, losing that "float above" sense conveyed by the F15s that others have ascribed.

I'll continue to use it for the woofer, crossing to meet the natural rolloff I've obtained from the F15s in the OB...which is somewhat below the nice sounding 100Hz exchange I setup when using the mini for both drivers. Too bad the miniDSP V1 high pass marrs the sound capability of the Liis - I wont trade that off for the better Xover frequency.

I'll probably keep the mini in service until I come up with something else. It's a great tool for designing speaker crossovers and I may need it someday for another project - who knows? $200 invested for the DSP / Dayton amplifier to drive the 18" assistants successfully. Measurement to follow -
 
Last edited:
lol i just bought this:

CX3400-V2_P0CCT_Right_XL_786273-d9271804e7312bc27201a6762c68d3c8.jpg


first time ever i have had any interest in pro audio gear. 3 moths ago if you told me id get this i would have never believed you. but if i am to figure this 2 way or even possibly 3 way, thing out, i think i need this.
 
Last edited:
it can also be a power supply issue. I have a lot of experience with that. i think the minidsp 2X4HD needs 12V. when i first started to use mine, i grabbled a 7 volt walwart by mistake from the pile of walwarts that i have. it worked but it sounded both quiet and also very bad. no dynamics. i was so dumbfounded i opened a thread on their support forum.

afte i figured it out, then i used this fancy top of the line linear power supply that i own and on the other end of the spectrum, it improved on the stock power supply.

i am sure that you are using the stock power supply but there is a small chance that it is not functioning at 100%. these walwarts do have a dud in them every once in while, being dirt cheap from china.its not very probable but it could be.
 
lol i just bought this:

CX3400-V2_P0CCT_Right_XL_786273-d9271804e7312bc27201a6762c68d3c8.jpg


first time ever i have had any interest in pro audio gear. 3 moths ago if you told me id get this i would have never believed you. but if i am to figure this 2 way or even possibly 3 way, thing out, i think i need this.
I've had a 2way plus sub and 3 way plus sub of those and tbh they are a bit rough and ready, were OK to work out what crossover points might work with my horns but eventually I bought DEQX ( the Australian unit not behringer ) for tri-amping. I now prefer single drivers, well I always have liked them, warts and all rather than adding subs and tweeters and definitely no crossovers.
 
@Kaffimann - I'll show my latest plots using the DSP just for low pass purposes in the next reply.

@Dadbeh - Well, I just grabbed a 12V from my pile of wall warts; I made sure to pick an analog one with the heavy 60Hz transformer inside. I could use one that's switche based, but my intuition says that's the wrong direction to go. Maybe sounds better that way, who knows? Congratulations on the EQ! Hope it's high pass sounds great.

@dave - when you say "What surrounds the DSP " do you mean at the level of op-amps on a circuit board, or the outside-the-box level of components?
 
So here's some plots describing the frequency response of what I'm getting using the 18" helper woofers, EQd by a miniDSP.

First are the miniDSP settings, basically I've implemented a 24db LR low pass @ 70Hz, followed by a reverse-rise to 25 Hz (see 1st screenshot). Check out the system measurement at the low end in the 2nd capture. (Realizing I'm a little bass heavy, but always been that way)

Today, I took a spin with REW and made my 1st swept sine measurement. :cheerful: I'm happy because I was able to take it through the process to ultimately create an impulse file - of a corrective filter set it created for me. See snap #3 of the swept sine and the correction it made. (This was just for the F15 alone)

Having saved these files and uploaded them into Daphile, my USB stick music player, it sure sounds different when you engage the convolution filter. Unsure if I like the more correct sound, however I do realize my ears could get used to it. I havent listened to it this way very much yet.

I owe another measurement as a trust but verify step - see how the REW analyzer shows the effect of all the filters it cooked up. I'll use my 15 minute Pink noise recording played back via Daphile...
 

Attachments

  • MiniDSP_Reverse_Rising.jpg
    MiniDSP_Reverse_Rising.jpg
    304.9 KB · Views: 656
  • Current Spectrum_12.jpg
    Current Spectrum_12.jpg
    349.5 KB · Views: 641
  • REW Sweep.jpg
    REW Sweep.jpg
    147.2 KB · Views: 617
Last edited:
I see some squiggles on there that could be related to the LR filter.
Have you tried applying a classic Halogen Bessel per the Rane document?
RANE Commercial - Knowledge Base

Quick'n dirty for 2nd order Bessel:
Desired xo freq x 1.272 = Low pass frequency
Desired xo freq x 0.786 = High pass frequency

I would try that, also with the minidsp. At least before dismissing the minidsp completely, it's not "perfect" in any way. And like mentioned before in this thread, the cheapest minidsp really shines with xo experimentation before purchasing costly passive components.

The reason I am thinking it might be some other issue is that: If the minidsp is working in a well matched setup, the flaws come out really easily with some higher frequencies and especially square waves. Most musical instruments produce sine at high frequencies, so it's usually not a huge issue.

The way I understand your problem, is that it sounds a bit "lean"? IE perhaps lacking a bit upper-bass/low-mid? With your huge passive components it could also be that there's some phase issue when bypassing them?

I apologize for pressing this matter a bit, it's just that, as Dave noted, I've seen several that "junk" their minidsp's. Just seems to me it's for the wrong reasons.
If you're done or don't want to deal with this, I'll just bow out and stop derailing the thread.

Nice that you've found a driver that you like, there's something about big FR's. :)
(Ps. Use the distortion plot which is automatically 1/12th octave smoothed, it looks nicer and it contains mostly relevant information in regards of the listening experience, helping you see what to improve and what you can put aside. Also set the borders so you can get 5db/div, use the distortion plot to hunt down various areas of improvement)
 
I'm just beginning to understand the REW filters. It provides a set, but you dont have to use 'em all, if you're partial to NOT having a pile of high order filters your audio signal runs through.

It's nice that you can click each on on/off and see the effect on the FR plot. Certainly at this stage of the game I dont need to make it "perfect", as it's a 1 Meter more or less on axis measurement point - not even at my listening position.

I can however "de-characterize" the F15's natural response using broader strokes, versus trying to address every wiggle seen in the FR with a high Q filter cut/boost. For example, the generally rising response between 300 and 2K. I'm trying to modify REW's suggestions to come up with a minimal filter set that makes this driver even better to listen to, than with no EQ.

Or perhaps the signal phase is getting knocked about by each and every wiggle - integrating on the high side of the bandpass, differentiating on the low - and the opposite corrective filter puts them back in their proper place, FAIK. Therefore the best sounding situation, for any given driver, would be to address each and every one; not only for amplitude correctness but phase also.

Maybe I'm just dreaming aloud here and that's not how it works. One way or the other should be best and I certainly dont know ;') Sometimes I just wish there was a normal graphic EQ - with sliders - that would output this .wav pulse for the convolution filter based on whatever levels the bands were set to.
Like the 31 band in Equalizer APO - but with just a convolution filter pulse output.
 
Last edited:
I like to nudge some of the more general dips & peaks a bit before doing another sweep, some times a little nudge in one part of the spectrum seem to influence response far away. It often pays off to hunt for resonant behaviour using the distortion plot and starting with the more troublesome peaks&dips, quite often the rest will look more tidy after doing a few tweak/sweep rounds on the biggest problems. Go for nice behaviour perhaps 5º to 20º or 10º-30º or something, don't pay much attention to 0º.

I don't pay attention to the REW auto thingy, it just looks at response and does nothing for resonance issues. Sometimes it sounds worse than no eq.
Always do another sweep after applying or tweaking any setting.

Edit:
The last few years I've been using this as a sort of standard routine and just forget about degrees and everything:
Run 4-6 sweeps in and around listening position (I usually stay within ca 1 to 1.5 meters), apply 12th/octave smoothing on all, look for peaks and dips that coincide on all measurements, adjust eq, repeat.
 
Last edited:
Thanks, KaffiMann. Looks like I have a new facet of this hobby, to play ad-nauseum with the infinite combinations of filters and Qs now available to me for EQ. I'm going to assume that in this day and age, most listeners "resort" to using some kind of EQ - or simply let their own ears train-out a mild "forward sound" to a major "rip your ears off" rising response.

Masters at this have told me they just like the sound of their (Lowthers) even though they realize the FR isnt ideal - it's the other qualities of the driver that, for them, reign supreme. I've only "de-characterized" the F15s with the EQ to make them appear a little flatter across the range.

So here's the latest FR plots - 18" assist included - with a reduced set of EQ bands obtained from REW. Gotta remember to SAVE those EQ settings! It's not that hard to recreate from the initial measurement...

The one dip just above 200 is there with any speaker I use in the same position - so I discount that as being Lii F15 specific. There's still some tweaks I can do on the miniDSP low pass function, but it's performing fairly well now. I've included 1/12 and 1/48 octave plots. Listening to them now I'm finding no objections with the gorgeous soundstage and sometimes scary player presence in the room.

I'll eventually follow up with some listening material review as heard through these as a wrap to this project. I realize I've just scratched the surface of what I can do with available multichannel sound cards, usb to I2S to miniDSP, analog implementations of 24 db LR filters with reverse rising response on the low-pass, REW and filter impulses - etc. So I know you're never quite "done".
 

Attachments

  • 1M-12th octave analysis.jpg
    1M-12th octave analysis.jpg
    329.2 KB · Views: 529
  • 1M-48th octave analysis.jpg
    1M-48th octave analysis.jpg
    370.1 KB · Views: 529
Last edited:
Thanks, KaffiMann. Looks like I have a new facet of this hobby, to play ad-nauseum with the infinite combinations of filters and Qs now available to me for EQ.

... Yeah, it's a bit double edged, like most compromises. Just try and go for minimum amount of eq needed for flat-enough response, you can get almost better results doing "less is more". But it takes more fine-tuning to get it just so. Modes under 300hz or so need a bit of brute force though. Do adjust a bit to taste, after a bit of tweaking most end up in the vicinity of the "JBL tilt". There's no right here, as long as you're happy that's all that counts.

Next up: Getting focused towards S/N ratio and start listening for noise floor in the recording studios.

Hope I'm not ruining your hobby :D
 
Last edited:
I'm getting the best sound that I have ever been able to achieve in my living room. this kinda sucks, specially for my wife since these ugly monster DIY OBs are gonna stay in our living room. I already sold my JBLs and I hava half a mind of putting my KEFs in the trash can. I thnk an OB was just the thing for this room. all the problems that box speakers presented are mitigated or gone with the OBs.
 
I'm getting the best sound that I have ever been able to achieve in my living room. this kinda sucks, specially for my wife since these ugly monster DIY OBs are gonna stay in our living room. I already sold my JBLs and I hava half a mind of putting my KEFs in the trash can. I thnk an OB was just the thing for this room. all the problems that box speakers presented are mitigated or gone with the OBs.
F15 in open baffle isn't perfection, what speaker is, but what it does well is so good I could live with them if I had the room. The most natural sound I think I've heard.