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InterMechanico

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Good Morning, Friend-Os!

I'm going to build two powered subwoofers to complement my Vistas Bottom end. I keep going back and forth on woofer selection, enclosure type and material, amplification, and in which order to choose them. I think I should choose my woofers first, and then build the enclosure around them, and finally choose my amplification.

I'm considering a number of possible driver manufacturers; Namely Scanspeak (Discovery 10", Revelator 9" or 13"), Vifa NE265W-08 10", or one of the Morel offerings (they have some nice offerings).

For the enclosure type, I'm leaning toward using passive radiators instead of porting, or sealed enclosures. I want these to be as small as possible, while still producing the low bottom end. It could be that a ported enclosure is the only way to go.

Stepping outside the box, so to speak, I'm interested in trying something very different for my enclosure material; Plastic, or more precisely, 1.5 inch UHMW. UHMW (Ultra High Molecular Weight) is very dense; more so than most hardwoods, and is perfectly uniform in its' construction.

http://www.interstateplastics.com/Uhmw-Black-Reprocessed-Sheet-UHMBR.php?sku=UHMBR&vid=201405161007-9p-C201405162250-86&dim2=24&dim3=48&thickness=1.500&qty=4&recalculate.x=145&recalculate.y=21

If I go that route, the most cost effective way to build them would be 12" x 12" Cube (729 cu. in) or 12" x 24" (1701 cu. in). I know that the 13" revelators are a no go in that configuration, but maybe they're that good that I could spend a little more on materials to accommodate them.

For Amplification, I would like to use a simple outboard amp (Dayton SPA1000) to power both, or look into some of the offerings for In Wall subs for other manufacturers.

Here is where you tell me where I'm making mistakes and over-simplifying.

PS: Is there any inexpensive software available for enclosure design?
 
Honestly, I'd post your questions in the DIY sub-forum @ AVS, or at DIYaudio.com. You'll get more knowledgeable help in a day than you'll know what to do with.

I'm kinda in the same groove, though I'm building an existing design, using 2x12" drivers in an OB M-frame of baltic birch.
 
Cool, do keep us updated on the progress.

But Ken is right, those other sites, DIYAudio.com in particular is pretty active and there are some amazing example projects there.

If you just want something simple, quick to do, I can recommend this parts-express dual-opposed 12" kit:
https://www.parts-express.com/dayton-audio-rs1202k-1000-watt-dual-12-subwoofer-kit--300-766

Do you have the option of doing an Infinite Baffle?

If so that makes all other subs cry for mercy. And cheap to build and power as well.
 
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Honestly, I'd post your questions in the DIY sub-forum @ AVS, or at DIYaudio.com. You'll get more knowledgeable help in a day than you'll know what to do with.

I'm kinda in the same groove, though I'm building an existing design, using 2x12" drivers in an OB M-frame of baltic birch.

Thanks for the advice, RUR. I haven't posted up there yet, but I did take some time to read up on some of the DIY projects there. There is a lot of valuable information there.

Have you settled on which drivers you'll use yet? I haven't done anything like this before, and am somewhat overwhelmed by the options available to me. I imagine that I should purchase the best components that I can afford, and try to find a safe and tested design to build to make sure I don't throw away a bunch of money...
 
Cool, do keep us updated on the progress.

But Ken is right, those other sites, DIYAudio.com in particular is pretty active and there are some amazing example projects there.

If you just want something simple, quick to do, I can recommend this parts-express dual-opposed 12" kit:
https://www.parts-express.com/dayton-audio-rs1202k-1000-watt-dual-12-subwoofer-kit--300-766

Do you have the option of doing an Infinite Baffle?

If so that makes all other subs cry for mercy. And cheap to build and power as well.

Thanks for the recommendation, JonFo. I have all options open to me, but my room is not tiny but not large 12' x 12', open behind the listening area.
I was initially inclined to build two smallish subwoofers, with frequency response as a priority, High SPL not necessary at all. I could easily tuck two small subs into their ideal locations without too much encroachment into my minimalist living room. I had a look at the Dayton Dual Opposed at Parts-Express, and although it is much larger, it is tempting considering its' cost/value. The only concern I have is placement; what if it doesn't work well in a corner, right?

Second option is as follows, and continues to develop: I keep rambling on in other threads about upgrading the woofers in my Vistas to something more efficient and more refined. That match-up is a little tricky, but not altogether impossible. If I did that, then I'd have the two original 8" woofers (or the new ones if the mod didn't work out) to build a couple of tiny subs.

Note: If I go the woofer replacement route, it would be accompanied by a change to separate amps and active crossover (eventually).

I haven't read too much information on Infinite Baffle Subs, but I'll make a point to include them in my decision.

I kinda feel like the Vista got short changed with the woofer. I'm 99 % sure that the Vantage woofer is different,; visually the surround offers my excursion. I realize it's powered, but I think the enclosure is the same volume. I'm thinking REVELator :D


This one fits quite nicely:

http://www.madisoundspeakerstore.com/approx-8-woofers/scanspeak-revelator-22w/4851t-8-woofer-paper-cone-4-ohm/
 
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Hi Julian,

The drivers I'm using are 16 ohm, paper cone, servo-controlled GR Research. They were designed by GR specifically for OB applications, so they'd be a very bad choice for you.

As for your drivers to be, I'd let the guys @ DIY audio advise. The cabinet volume/design will dictate certain driver parameters (or vice versa), so it's best to look at cabinet and driver as a whole.

Ken
 
Julian, you're building a sub? I thought you had neighbours to worry about!

I do! I'm looking to round out the bottom end more than rattle the windows.lol. I think the vista drops off around 43 hz, and in my room, I suspect it's higher. I will do some testing before I go to far, though.
 
I do! I'm looking to round out the bottom end more than rattle the windows.lol. I think the vista drops off around 43 hz, and in my room, I suspect it's higher. I will do some testing before I go to far, though.
You should consider buying the Dayton Omnimic to do some measurements.
 
A mic and some measurement software is at the top of the list! If you recommend that model, that'll work for me. Who knows, I may identify some correctable problems, negating the néed for a sub
 
+1 on the Omnimic. A terrific tool, it may help you find a better location for your sub, such that you don't need another. Plenty of other helpful uses, too.
 
PS: Is there any inexpensive software available for enclosure design?

WinISD
http://www.linearteam.dk/?pageid=winisd

A cheaper alternative and tons of free support would be a mic from Cross Spectrum Labs (http://www.cross-spectrum.com/) and Room EQ Wizard (http://www.roomeqwizard.com/). There's tons of options for the drivers, personally I like large 12"+, high power, and high xmax subs (preferably with shorting rings) like Dayton HF/HO, Stereo Integrity, and TC Sounds with a high powered pro amp.

With an Omnimic or CSL mic + REW you'll be able to see the peaks and dips. If you want to take it a step further pick up something that can apply PEQ filters like a MiniDSP and bring down the peaks. There's also a few pro amps with DSP options like Behringer iNuke DSP or Crown XTi Series 2 (I have a Crown XTi2002 and it's very nice).
 
Is this the correct product? It seems obvious, but I'll ask anyway.

http://www.parts-express.com/dayton-audio-omnimic-v2-precision-measurement-system--390-792

Alternately, Ken brought forward the new arrival of the Dirac Series DSP from MiniDSP; would that be a reasonable solution? It comes with a mic and software, and offers room correction. Also, no one here has tried it out yet, so I could Guiney Pig it. Analog or digital though? I don't use a DAC between my two sources and my Integrated Amplifier. I do use both sources equally. Are splitters (balanced/unbalanced) very very wrong? I could go with the analog model and report back when I get it worked out.
 
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Alternately, Ken brought forward the new arrival of the Dirac Series DSP from MiniDSP; would that be a reasonable solution? It comes with a mic and software, and offers room correction. Also, no one here has tried it out yet, so I could Guiney Pig it.

A few of us have played with the Dirac PC software which is free to try for 2 weeks. I didn't mess with it too much (I should try another 2 week demo) but I felt like with my ESL's it didn't make a difference worth the price IMO. For bass I think you can get pretty close with a USB mic + REW + a DSP with PEQ for a bit cheaper (around $250 depending on the models you choose). For mids and highs the ESL design takes out a lot of the room anyway...
 
Random thoughts on using Dirac....

The principal difficulty with using any "advanced" EQ solution is that there's a bit of a learning curve. First, you have to sort out all the features e.g. gain and delay control, EQ limits, if any, target changes, etc. etc. Then, you need plenty of time to experiment in order to determine what works and sounds best. I say this, not to deter folks or to make it sound difficult, because it's not, but because a certain amount of time and effort is required. If, as some have done, you're doing this within a two week trial window, I'd recommend that you make the most of those two weeks.

Take time to play with various permutations of target curve. I cannot recommend this enough! Everyone's system/room/preference will be different, and you'll only find your happy place by trial and error. As a starting point, I'd suggest trying various tilts from 50Hz to 20kHz. More downward tilt will emphasise lows and mids, while simultaneously masking high frequencies. Less tilt will have the opposite effect. Start at a few dB down - say 50Hz @ +2dB, smoothly tilting to 20kHz @ -2dB - see how it sounds, then adjust to taste. Once you've found a rough curve which pleases, you can experiment endlessly with bottom and top end rolloff, mid-range boosts, etc. etc. etc.

If you're confused, or it's not sounding right, get help. I dunno if Dirac has their own forum, but I do know that a Dirac employee, named Flavio, actively provides advice in the Computer Audio forum. I can provide years of experience with SoTA EQ, in general, but I've not used Dirac and so may not be able to help with specifics.

Hope I haven't scared anyone off. I'm a HUGE believer in the benefits of SoTA EQ, even with good gear in good rooms and, yes, even with dipoles. With a little effort and some assistance, you could be, too.
 
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Thanks for the recommendations, everyone. I'm not 100% certain yet, but before I do any subwoofer building, I'm definitely going to order a mic and some measurement software. The only question in my mind is which way to go.

So far, I'm leaning toward getting a MiniDSP 4x10 HD along with a Umik-1 and I'm looking at REW.

Ken, you're probably right; I think Dirak is over my head, and I'm sure most features would be somewhat wasted on me. I may just be slow :rolleyes:, but I've tried to find some info on SoTA EQ, but come up with nothing. Would you mind posting a Link please and thank you?

My thoughts on the 4x10 HD are that that it will initially provide me with the ability to perform some room correction, but going forward, I can use it as an active crossover in the future, when I get around to playing with that.

The next option is to go with (2) Mini DSP 2x4's (one for each source) which would be cheaper but messier

The last option is an odd one, but I could go fully active on my Vistas with a couple of 2ch plate amplifiers with DSP built in (Mini PWR-ICE250). I know that Class D amps aren't ultra highly recommended, but I'm running an 85 WPC Yamaha integrated right now, so I'm not convinced the Ice Modules would necessarily be a step down.

Any Thoughts, If anyone is still interested?
 
Ken, you're probably right; I think Dirak is over my head, and I'm sure most features would be somewhat wasted on me. I may just be slow :rolleyes:, but I've tried to find some info on SoTA EQ, but come up with nothing. Would you mind posting a Link please and thank you?
Julian, it absolutely won't be over your head, and I sure didn't want to give anyone that impression! Yes, Dirac will have a learning curve, but once you've figured it out it'll be duck soup. And finding the ideal target curve isn't hard at all - it's just time consuming. SoTA=State of the Art, IMHO Dirac, Trinnov and maybe a couple of other PC-based products which really would be challenging for many e.g. Audiovera.

My thoughts on the 4x10 HD are that that it will initially provide me with the ability to perform some room correction, but going forward, I can use it as an active crossover in the future, when I get around to playing with that.

The next option is to go with (2) Mini DSP 2x4's (one for each source) which would be cheaper but messier
Both of these non-Dirac miniDSP products are IIR filter only. Fine for bass, problematic for higher, non-minimum phase FR.

The last option is an odd one, but I could go fully active on my Vistas with a couple of 2ch plate amplifiers with DSP built in (Mini PWR-ICE250). I know that Class D amps aren't ultra highly recommended, but I'm running an 85 WPC Yamaha integrated right now, so I'm not convinced the Ice Modules would necessarily be a step down.
I always wanted to go active with my Summits, but was afraid I'd compromise resale. Having said this, the PWR-ICE250 is 2nd gen ICE and *should* have no problems with the ESL's wacky impedence. Same EQ caveats as for the 4x10 and 2x4 miniDSP i.e. bass correction only is advised.
 
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Julian, it absolutely won't be over your head, and I sure didn't want to give anyone that impression! Yes, Dirac will have a learning curve, but once you've figured it out it'll be duck soup. And finding the ideal target curve isn't hard at all - it's just time consuming. SoTA=State of the Art, IMHO Dirac, Trinnov and maybe a couple of other PC-based products which really would be challenging for many e.g. Audiovera.


Both of these non-Dirac miniDSP products are IIR filter only. Fine for bass, problematic for higher, non-linear phase FR.


I always wanted to go active with my Summits, but was afraid I'd compromise resale. Having said this, the PWR-ICE250 is 2nd gen ICE and *should* have no problems with the ESL's wacky impedence. Same EQ caveats as for the 4x10 and 2x4 miniDSP i.e. bass correction only is advised.

Thank you! That is great information, and much needed. I've back tracked to our original discussion of the Omni-Mic from Dayton Audio. I ordered the setup, and the best thing to do now is analyze my room, and go forward from there. I'll post the results in a week or two when it all arrives and I have a chance to try it out.

Thanks Again!
 
Thanks for the recommendation, JonFo. I have all options open to me, but my room is not tiny but not large 12' x 12', open behind the listening area.
12x12 is small, but more importantly, square, which causes challenges if totally enclosed, but you mention 'open' so from a bass perspective, how big is the 'room'?


I was initially inclined to build two smallish subwoofers, with frequency response as a priority, High SPL not necessary at all. I could easily tuck two small subs into their ideal locations without too much encroachment into my minimalist living room. I had a look at the Dayton Dual Opposed at Parts-Express, and although it is much larger, it is tempting considering its' cost/value. The only concern I have is placement; what if it doesn't work well in a corner, right?

Now that I know more about your room, I would strongly suggest you stay on your original concept of two smaller subs placed in deal locations. Multiple small subs can be a tremendous way to gain low-frequency balance in tough rooms. To see just how far one can go with small budget, I performed an experiment in my second system that worked out way better than I expected, check out my thread on using four subs.

Second option is as follows, and continues to develop: I keep rambling on in other threads about upgrading the woofers in my Vistas to something more efficient and more refined. That match-up is a little tricky, but not altogether impossible. If I did that, then I'd have the two original 8" woofers (or the new ones if the mod didn't work out) to build a couple of tiny subs.

Note: If I go the woofer replacement route, it would be accompanied by a change to separate amps and active crossover (eventually).

I kinda feel like the Vista got short changed with the woofer. I'm 99 % sure that the Vantage woofer is different,; visually the surround offers my excursion. I realize it's powered, but I think the enclosure is the same volume. I'm thinking REVELator :D


This one fits quite nicely:

http://www.madisoundspeakerstore.com/approx-8-woofers/scanspeak-revelator-22w/4851t-8-woofer-paper-cone-4-ohm/

That's a lovely driver, but do check your Vista for fit, I believe the original Vista woofer is a truncated frame woofer to fit the narrow width of the enclosure.

But yes, requires an active x-over if swapping the woofer. But I'd experiment first going active and using the factory driver, as it seems like decent unit.
 

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