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Flex Your PCD Mettle:

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  • gmannel
    replied
    Re: Flex Your PCD Mettle:

    OK great - as to the baffle I would front flush mount the WG, and rear mount the woofer? 3/4" difference as w/ the Deluxe? Do I need to passively High pass the whole box say at 60 or 80Hz or just let the miniDSP do all that(which as of now I know nothing about). In it's eventual HT setting(hopefully will work as a decent center channel) control will be from the AVR's Audyssey MultiQ XT32.
    I am only building one(for now, maybe the would be decent surrounds as well? Was going full height LA for surrounds but who knows).
    Have lots of 9 ply 1/2" BB on hand so was thinking would laminate to 1", or could use 3/4 MDF. A 1 cf box is small so whatever is best.
    In building this, I also want to learn, so to that end I have acquired a Cross Spec Labs calibrated Dayton mic, and a Tascam 122MkII "sound card" to plug into a laptop. What would yall suggest I load up on the laptop to do measuring, modeling, polar maps, etc and any other essential hardware?
    Finally, would the miniDSP be a permanent xover, or do I make a passive one from the final DSP settings?

    Leave a comment:


  • Pete Schumacher
    replied
    Re: Flex Your PCD Mettle:

    Originally posted by gmannel View Post
    Design recomendations

    Using the B&C DE250-8 1" + QSC PL-000446GP Replacement Waveguide Horn for HPR152i (or different if you rec)
    and bass is covered by 15" Dayton Titanic Tuba HT 24"
    and the LR are MCLA w/ 16 each http://www.parts-express.com/pe/show...number=295-338
    What would ur rec be for the woofer in a 2 way single center channel speaker and what crossover point - could do w/ biamped miniDSP as well as a passive
    I like Dayton Ref drivers but pro OK if better.
    That guide/tweeter combo is begging for the or Deltalite 2512 in a sealed, stuffed, 1cf enclosure.

    Leave a comment:


  • gmannel
    replied
    Re: Flex Your PCD Mettle:

    Design recomendations

    Using the B&C DE250-8 1" + QSC PL-000446GP Replacement Waveguide Horn for HPR152i (or different if you rec)
    and bass is covered by 15" Dayton Titanic Tuba HT 24"
    and the LR are MCLA w/ 16 each http://www.parts-express.com/pe/show...number=295-338
    What would ur rec be for the woofer in a 2 way single center channel speaker and what crossover point - could do w/ biamped miniDSP as well as a passive
    I like Dayton Ref drivers but pro OK if better.

    Leave a comment:


  • Zvuchniak
    replied
    Re: Flex Your PCD Mettle:

    Originally posted by dtruck View Post
    ........... the method I think you're describing is a fairly accurate simulation in bass impedance with an extrapolation based on Le into the midrange.
    Quite right. I thought that is what you're looking for.

    Regards

    Leave a comment:


  • dtruck
    replied
    Re: Flex Your PCD Mettle:

    Zvuchniak, thanks for the offer, but what I need is a precise impedance curve in the midrange, while the method I think you're describing is a fairly accurate simulation in bass impedance with an extrapolation based on Le into the midrange.

    I already performed the measurement method that you linked to, and it matched physical measurements - that's in the AK thread linked in my post above. However, my frequency responses are still a little suspect, IMO, so the project is somewhat on-hold while I try a bunch of things to identify and reduce any flaws in my impulse measurements. I may have a post on here regarding that tonight if I don't get anywhere new..

    Leave a comment:


  • Zvuchniak
    replied
    Re: Flex Your PCD Mettle:

    Originally posted by dtruck View Post
    I think they will be, someday. Btw, bwaslo, if you were to download my PCD files, you would find "TD15M_bwaslo_shifted_down.zma". I am using your impedance measurement divided by 2 as a stand-in until I get a real one.
    If you tell me internal box volume and tuning frequency, i can calculate your speaker impedance based on that and TS parameters using Frequency Response Modeler.

    If you want

    Use Jeff Bagby's guide how to measure so we can use it in PCD knowing it will work. Download it from here:

    http://www.box.net/shared/ouxjjsx0m8bs00cil5iq

    Leave a comment:


  • bwaslo
    replied
    Re: Flex Your PCD Mettle:

    Well, you can blame me if there are problems, then!

    Using a 4 ohm driver is what I wanted to do, but not what I had. It will give you about another 3dB in sensitivity (not efficiency, but if you use a class D amp, it comes to about the same thing). A little T-Amp would even do well.

    I found that it all works best with the speakers up on stands, so the woofs are several ft off the floor and the tweeters are at ear level. And of course, toe-in. Plan to spend a lot of time listening to music when you get them done, and for your friends to tire of hearing about your speakers.

    Leave a comment:


  • dtruck
    replied
    Re: Flex Your PCD Mettle:

    I think they will be, someday. Btw, bwaslo, if you were to download my PCD files, you would find "TD15M_bwaslo_shifted_down.zma". I am using your impedance measurement divided by 2 as a stand-in until I get a real one.

    Leave a comment:


  • bwaslo
    replied
    Re: Flex Your PCD Mettle:

    dtruck, that should be a phenomenal set of speakers.

    Leave a comment:


  • dtruck
    replied
    Re: Flex Your PCD Mettle:

    If anyone is interested in helping me use PCD for the first time (just pointing out mistakes, would be great), I've got a build started. Initial measurements and PCD attempts (with files) are posted here. More measurements and files will be coming. I'll post them here as well, if I haaaaave to.

    It's a DE250, QSC HPR152i waveguide, and Lambda TD15M-4.

    I could probably use a few tips on taking measurements, too.
    Attached Files

    Leave a comment:


  • bkillen
    replied
    Re: Flex Your PCD Mettle:

    an in-wall mounting could affect mid-bass a bit. With a mini-8 I don't think it will be of much concern. I would be more concerned in making sure your in-wall design includes adequate toe-in of the speakers. This pretty much means the best location for in-wall will be actually building the corners in at an angle. this toe-in is really important in a constant directivity design.

    Leave a comment:


  • voodoo2crue
    replied
    Re: Flex Your PCD Mettle:

    Hey guys, long time lurker here first time post.Was wondering if there is any info on inwall econwaves that have been built. I did a few searches and couldn't find much. I built a pair of the mini 8 econowaves and have thought about converting them to inwall if possible.Would it be as simple as keeping the same cu.ft for the enclosure size or would crossover changes also need to be made.

    Leave a comment:


  • Zvuchniak
    replied
    Re: Flex Your PCD Mettle:

    Does this setup match the mounting configuration from the test data? That data shows an easily defined offset for the particular mounting conditions, and a mic position in between the woofer and tweeter. If you design for the tweeter being on axis, it will help push the woofer acoustic center farther back.

    Just remember, all that will change is the listening axis, and not by that much, so you can adjust tweeter height to suit.
    Everything is exactly as Zilch did it. Even the thickness of front baffle Midpoint between midbass and tweeter is in ear hight. Stands are custom made for it.

    Leave a comment:


  • Pete Schumacher
    replied
    Re: Flex Your PCD Mettle:

    Originally posted by Zvuchniak View Post
    That FRD and ZMA files are from econowave delite so we are talking about the design that is already done. Measurement provided by Zilch.

    So it is not the question of what i want. It is more about what should we do in case that you can't change the speaker cabinet. What you see is what you get

    Does this setup match the mounting configuration from the test data? That data shows an easily defined offset for the particular mounting conditions, and a mic position in between the woofer and tweeter. If you design for the tweeter being on axis, it will help push the woofer acoustic center farther back.

    Just remember, all that will change is the listening axis, and not by that much, so you can adjust tweeter height to suit.

    Leave a comment:


  • djg
    replied
    Re: Flex Your PCD Mettle:

    Thanks Pete. I will probably make a new baffle and rear mount the woofer as Zilch did his PA cab version of the original standard Econowave version.

    Leave a comment:

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