Fearful 1212sub / Headcase Idea...Need Help.

[MWBass]

I made a comment on this in the fearful megathread and they said I should start a new thread, so i am...

I am going to just pull some of the post from over there...

I have been looking for a new rig the last few weeks. Fearful cabs have been interesting to me for a while now. They weren't in my short list, but I build basses as a side job, so I have the tools to make the work easy and I trust me ability to construct. I think it could be a fun build and an interesting product that could give me great results as I have heard.

My question is this. I had a lead on a new Eden WTX1000N. The head allows biamping with an appropriate crossover, so I thought it would be cool to possibly build a headcase and a 1212 sub. I thought that would be plenty substantial enough to get me through my gigs.

My initial goal was to have a combo, or small set up, that I could add an extension too with extra power to turn into a stage rig.

My problem was that I want a really small bedroom practice combo, and a powerful stage rig. Ultimately I would like something small I can use at home and for small bedroom writing sessions, and a way to add to it to get a monstrous stage rig.

That got me thinking. Suppose I made a 1212 sub, and a headcase, but make the case for the headcase large enough to incorporate the head and a small woofer that will allow it to be turned into a small combo. Nothing for stage play, but just a small practice combo for me and for when we write.

THis would kind of really take advantage of the biampability. I make the headcase on one side of a box, vertically holding the midrange in its chamber and the tweeter in another. Then on the other side, I build a separate ported chamber for a small 8"woofer.

The midrange and tweeter will be made to spec with apprpriate passive crossovers for midrange to tweeter. Then I would run the high pass of the amp, with adjustable crossover to the headcase portion, and the low pass to the 1212sub. The other side of this case would have an 8" woofer in its own vented chamber. It would be set to cut out the ultra lows at the appropriate frequency, and have its own input. When I didn't want to use the monster rig, I could unplug the low pass to the 1212sub, plug it into the 8's input adjust the crossover on the amp if need be, and grab the top as a tiny practice combo.


Now, I know the combo wouldn't be optimal, but I am sure it would kill and a bedroom / house practice setting.

So, my question is, does anyone know of the best 8" woofer that I could use ... excursion, spl, power handling, etc... and what an aprropriate box volume would be for that driver.

I have WinISD, but I am incredibly confused by this technical stuff. It would be great if someone could impart there wisdom on me.

As I said, the combo wouldn't be perfect, but good enough for small writing sessions and home practice, and the 1212fsub when its time to rock out.

Any help would be appreciated. Thanks.

 

[MWBass]

Now, I already got some fedback in the other thread, but this is what I am curious about if anyone can help me out, I would appreciate the help...

The Faital Pro 8PR200 looks nice. I don't know much about these theil small parameters, not much at all, but I have just been looking at 8's that have high SPL, and high xmax. I figure they will be able to present the lower frequencies at higher volumes without dumpin out.

The only other one I see that is close is the 18 Sound 8NW900. It looks to be more efficient by 2 or 3 and the xmax is only 1mm less.

I'd assume the price will be similar between the two.

The only big differences...

18 Sound 8NW900 - Higher efficiency.

Faital Pro 8PR200 - Has slightly better xmax and has a mechanical Q about the same as the Kappalite 3015LF. I have no idea what mechanical Q is, but its around 2.3 on the 18 Sound. I dunno whats better.

Questions...
1. Any ideas on which one of these drives would do a better job matching up with the 6ND410?

2. Any idea what internal volume would work decent for the 8" drivers enclosure? (obviously doesn't need to be perfect for the practice combo)

3. At what frequency would be good to filter out the ultra lows 50, 60hz?

4. Is there a stock piece that will do this?

Just curious about anyones thoughts. Thanks.

 

[1n3]

This idea has crossed my mind from time to time. Seems like great modularity - a high-power head that has it's own small speaker for practice, which can also serve as the top of a two-way speaker system.

Obviously, it would be an exercise in compromise, and it sounds like you understand that. A speaker like the 18Sound 6ND410 is right out, since it can't do full-range.

Something like a Deltalite 2510 would work well for full-range, but doesn't have the HF dispersion or extension of smaller speakers. That kind of brings you around to 8s. One speaker I've considered for this use is the Eminence Beta 8a. It's fairly cheap, has good sensitivity, and handles decent power.

After reading edwinhurwitz's post in the other thread, I spent some time modeling the Faital Pro 8PR200 and 8FE200 in WinISD, comparing them to three Eminence options: the Beta 8a, Alpha 6a, & Deltalite 10.

Of the 8s, the 8PR200 has the best LF extension, and the most excursion. Displacement and thermal limits are almost the same; impressive bass performance for an 8" speaker. The tradeoff is sensitivity above 150hz, where all the other speakers beat it.

The 8FE200 edges the Beta below 150hz; above that number, it reverses. The Faital's higher xmax wins down low, but the Beta's higher power rating would win in a midrange application.

The Alpha 6 was of interest for a couple reasons: It is nominally a full-range speaker, though with fairly weak bass performance. It's also a recommended mid for the fEARful 12+6. Two Alpha 6s might give acceptable performance for practice, and could be used with a fEARful crossovers along with a 1212 sub.

One reason for going this route would be to maximize available power, with bridged output to the entire rig. But I see the Eden WTX1000N can't be bridged, so that's moot. Another reason for using Alpha 6s would be to tilt the design compromise toward gigs (better HF dispersion/extension). If you were going to use a tweeter, that might also be moot.

Of the 8s, you might still need two to keep up with two 3012LFs; would depend on how loud you run, and your tonal preferences. I assume the 8PR200 would sound best alone, but it's a pricey bugger. If you can afford two, that might be your winner.

Between the Beta and the 8FE200, performance is close, and they're about the same price. I'd take the Beta based on it's higher thermal rating.

So... there's my armchair exploration. Take it with a grain of salt, being based almost entirely on specs.

 

[1n3]

Didn't look closely at your second post; was going off the other thread. See you had some more questions...

The Faital Pro 8PR200 looks nice. I don't know much about these theil small parameters, not much at all, but I have just been looking at 8's that have high SPL, and high xmax. I figure they will be able to present the lower frequencies at higher volumes without dumpin out.

The only other one I see that is close is the 18 Sound 8NW900. It looks to be more efficient by 2 or 3 and the xmax is only 1mm less.

Xmax is 5.8mm, vs 8.15mm for the Faital. The 8PR200 outperforms the 8NW900 below 100hz, but above that, the 8NW900 wins. That's the usual tradeoff - low extension vs. broadband sensitivity. The 8NW900 is about as sensitive as the Beta, but it can take more power than the Beta.

1. Any ideas on which one of these drives would do a better job matching up with the 6ND410?

Neither. They would be used instead of the 6ND410.

2. Any idea what internal volume would work decent for the 8" drivers enclosure? (obviously doesn't need to be perfect for the practice combo)

Depends on the driver and how you want to tune it. Range is probably .5-.8 CF per driver.

3. At what frequency would be good to filter out the ultra lows 50, 60hz?

Yeah, something like that.

4. Is there a stock piece that will do this?

I assume you're talking about a hi-pass filter. You'd want to do that at the preamp level, since the power-level components would be too large, heavy, and expensive. Fdeck's preamp comes to mind; it has a HPF. Or, you could just turn the bass control down, and be careful.

 

[MWBass]

OK, 1N3, I see what your saying.

So, Instead of using the 18 Sound Mid, I would use the Faital Pro 8PR200 as the mid in the headcase / 1212sub combo. It would be crossed over somewhere between 500 and 800 hz, most likely. Then when I wanted just the combo, I could switch the head from biamp mode to full range stereo and let the 8 go all of the way down to as low as it goes and it would serve as a full range driver.

I understand why two 8's would be better then one, then the 95 spl would be more like 98+ with two working together. This would work fine if both of the PR200's were 8 ohms. They would create a 4 ohm load. So, in the biamp, the 2 eights / tweeter (yes, id probably have the tweet) would receive 500 watts on the high pass, and the 1212sub would recieve 500 watts as a 4ohm load on the low pass.

Then when I switched to just the combo, I would switch the amp to full range stereo, and the two eights would act as a full range 2-way 500 watt combo with the tweeter. Sounds pretty sweet.

Here are my concerns and the reason for my original design...

I am assuming that the PR200's would need to be in a vented enclosure to get the best low end output possible. This would be great as the full range combo, but as the midrange in the biamp, would the vented enclosure serve well as a midrange? I see that on all of the other midrange enclosures, they are sealed. What would happen if the 8's were sealed? What would bass output be like in the lowest frequencies?

My concept was to literally make the 1212sub, and the headcase exactly to spec, so that the system works perfectly. Then the headcase would have another chamber off to the other side for a vented enclosure for the PR200. Then I would just run the low pass of the biamp to the 8 instead of the 1212sub when i wanted to use the combo. Now, the output of the 6 mid and the tweeter would be much much higher than the single 8 due to the super high efficiency. However, when the head is in biamp mode, the balance control on the amp can serve as an attenuating pad to either side of the biamp, so, I can roll it towards the LP side until the output is matched. The downside is that two eights running full range in the other design wouldn't be as load. Also, the single 8 wouldn't have the low end of the two 8 design.

So...

1. Make the headcase / 1212Sub the way i was thinking of designing it...

Pros - When the full rig is in biamp mode and the 8 is not receiving signal, it is exactly a 1212sub with headcase, designed just like the fearful design, with all of its wonderful balance and design, all spec in place. Also, when the combois used, it would be 600 watts, 300 to the 8" 8 ohm Woofer, and 300 to the midrange / tweeter.

Cons - When the combo alone is in biamp mode and the balance is used to adjust for equal output, the volume output will be lowered. The combo will bring the 18 sound mid / tweeter down to match the efficiency of the 8" PR200.

2. Make the headcase / 1212sub the way you suggested, using 2 Faital PR200's as mids / full range.

Pros - When in combo mode, the two eights will both be running full range. So, the combo will be more efficient. and the bass output will be better.

Cons - In biamp mode for the full rig, the two eights will serve as midranges. They are not any of the midranges suggested or tested for in the fearful setup. However, they could perform very well, but the box may need to be vented which could change their midrange performance. Also, the combo will get 500 watts from one side in full range stereo mode, so won't have as much power as the other set up.

Decisions, decisions. Very interested in this, but which direction is better to go. I need to know more about these 8" Faital PR200's and whether or not they should be in a vented or sealed enclosure...

Which way do you think would be better?


2.

 

[Derek Kiernan]

Maybe I missed it (I glanced over now after reading the posts earlier), but do you have a strong aversion to making the 12/6 for the smaller setup? You could install switchable padding, make a 12sub, and take off the padding when you want to use them together. This way you can get optimal results and not risk anything by going off into uncharted waters.

 

[MWBass]

I thought about it.

My only issue is that if I were to make the 12/6 cube into a combo with an airhead, it would be about 25" by 20" by 15" To me, that is real big to use as a practice amp, basically like a 212 size.

This combo would be 20" by 16" by 17" about the size of a 112, and probably under 30lbs.

My basic thought is if I had a 12/6 i used for practice and then threw a 112 under it for shows, it won't be that far off.

With this, i have a tiny combo that is in the same tonal spectrum, but light and super easy to move around. Then when i switch to the big rig, its a massive punch in the face volume wise, which is what I expect on gameday.

I'm definetly not trying to stew the pot here, I want to stick to the fearful specs. I just figured with the headcase portion, I can do something that really works for my needs.

 

[4Mal]

Easy answer... Just build a small 1x10 bare, no filters, tweets, not nutin' extra as your practice/bedroom/coffee house/wine bar cab. Hold the f'cab back until you need the big gun.

I gig my MojoSonic 1x10 Way more often than one of my 12.6 cab's - let alone the pair of them... Granted I do a lot of acoustic support work but some of it is in at least medium sized rooms. The little 1x10 is an incredibly practical solution... Which I'm cloning as a combo using a GK MB500.

 

[MWBass]

I hear ya man. I use my M-Audio 8" monitor now, just plug straight into the 1/4 input and use my basses eq.

It serves me well.

It just weighs like 35 lbs or so. About 10" by 12" by 17". I figure at less weight and just a little bit bigger, this thing would trump it soundwise and once again, i'm still following Fearful design to a T, or as best as I can build it to a t.

 

[MWBass]

I just realized, in my headcase combo design there is enough room for about 1.5 cubic feet of internal volume. I could even use a 10". And since they come in at like 4.5/5 lbs, the weight will be the same.

Anyone know any good 10" drivers with high spl, xmax, etc.?

Over here... http://www.usspeaker.com/homepage.htm...

the Faital 10FH500 looks good and the B&C 10NW64 is about 2 lbs. heavier, but specs out nice.

I'll take any advice on the best 10's out there to do the job. Thanks.

 

[Derek Kiernan]

You might be interested in making Duke's Low-cost DIY practice/coffeehouse tweeterless 110. It should perform well enough for bedroom practice, be minimal DIY effort, and save you a bit of cash for when you end up doing the fEarful.

 

[MWBass]

Looks pretty cool, but the same issue comes up. Its a nice small box at 22 lbs, but i also have to carry the head. at 11 pounds and the two of them together would be virtually the same as the combo. The cost of the driver is the only real difference between what I am going to do and this. I am sure this sounds great, but I don't need the combo practice side to be that great, just usable.


Derek, the following is not directed towards you, just so you know. Your suggestions have been welcomed...

It just seems like so many people feel that this is such a terrible idea. I don't understand. I'm not straying from fearful design. I am just adding something into the headcases box that allows it to occasionally be a combo. I'm not claiming its going to be the end all combo, just good for me. I personally find it more appealing then carrying a bigger box and head as separate pieces. I justy don't understand which woofers would work best for the application.

 

[Sundogue]

I've thought of the same thing. And it is a good idea.

Build an amp rack/combo that holds the head, and something like a single BP102 with an 18Sound 6" mid. You should be able to boost the lows and dial out the mids and highs to balance with a single BP102 for lower volume practicing.

This would be your headcase and single practice combo. Put an extra jack in the headcase along with a switch that kills the connection to the BP102 and engages the other jack.

That way you can use the headcase combo alone, or flip the switch to kill the BP102, engage the other jack and then connect it to the fEARful sub without the BP102 in the loop.

 

[1n3]

So, Instead of using the 18 Sound Mid, I would use the Faital Pro 8PR200 as the mid in the headcase / 1212sub combo. It would be crossed over somewhere between 500 and 800 hz, most likely. Then when I wanted just the combo, I could switch the head from biamp mode to full range stereo and let the 8 go all of the way down to as low as it goes and it would serve as a full range driver.

Yeah, that's how I'd see it.

I understand why two would be better, then 95 spl would be more like 98+ with two working together.

Actually, you'd gain about 6dB - 3 from doubling the speakers, and 3 from doubling the current. The same goes for the woofers, which is why a single 8 might be outgunned. Biamping, you could compensate for the difference in sensitivity, up to a point. It helps that you "only" have 500w for the woofers, and that there's less content and power demand above 800hz. The 8PR200 is roughly as sensitive in midrange as the Alpha 6, which balances one 3012LF. To get a 6dB increase, you'd need to feed one 8PR200 four times the power.

So, in the biamp, the 2 eights / tweeter (yes, id probably have the tweet) would receive 500 watts on the high pass, and the 1212sub would recieve 500 watts as a 4ohm load on the low pass.

Then when I switched to just the combo, I would switch the amp to full range stereo, and the two eights would act as a 500 watt combo.

Yes. I assume you'd need a switch on the tweeter, to attenuate it when running in "combo mode".

I am assuming that the PR200's would need to be in a vented enclosure to get the low output possible. This would be great as the full range combo, but as the midrange in the biamp, would the vented enclosure serve welll as a midrange? I see that all of the other midrange enclosures are sealed. What would happen if the 8's were sealed? What would bass output be like in the lowest frequencies?

That's a compromise. You'd need to port and size the mid cabinet appropriately to get much bass out of the mid driver(s). By optimizing the cabinet for bass output, you'll lose some sensitivity higher up. I don't think it would be a lot, but that's really beyond my expertise. Maybe someone else can comment on that.

My concept was to literally make the 1212sub, and the headcase exactly to spec, so that the system works perfectly.

As far as I know, there is no spec for the headcase, just some guidelines. That's custom territory.

Also, the combo will get 500 watts from one side in full range stereo mode, so won't have as much power as the other set up.

It seems unlikely you'd pump 600 watts into the combo. If you wanted extra headroom, you could add jacks/wiring to run two mids stereo, and hang the tweeter off one side. That would be a lot more complication for an additional 100w.

I wouldn't want to carry a speaker that would be disabled in any configuration - that would defeat the purpose for me. And if you want to do the practice combo, the 18 Sound 6ND410 doesn't makes sense - it can't do full-range, and wouldn't work well with another midrange.

I'm not necessarily recommending the Faital 8PR200. It appears to be the best full-range, but probably not the best mid-range. There are pros to using the other speakers too.

The Eminence Alpha 6a (2) is recommended for the 3012LF, and the tweeter crossover is designed for it. But in combo config, two Alpha 6s would be weakest on bass.

The 18 Sound 8NW900 & Eminence Beta 8a have higher sensitivity and power handling than the Alpha, so are the best candidates for working as a single mid/combo driver. Combo performance would not be as good as the 8PR200.

I don't know if one 8PR200 would do the job as a mid driver. OTOH, two 8PR200s should, and with 500w would be a giggable amp in some settings. Baby Blue on steroids...

The cost of two 8PR200s is not insignificant. Not a factor for you?

To any fEARful owners - any idea how much power you're sending to your mid driver at war volume? Also... has anyone here used the 8PR200?

 

[BassmanPaul]

If you are going to go to all this trouble why not just build the standard headcase and a pair of 12" subs? You can use the headcase with one sub for practise and both for gigs.

 

[1n3]

If you are going to go to all this trouble why not just build the standard headcase and a pair of 12" subs? You can use the headcase with one sub for practise and both for gigs.

Speaking only for myself, as one who is interested in the OP's concept... This is a solution to a different goal. The concept as I see it: take a lightweight head, add a small full-range speaker to create a small combo that is not much larger or heavier. Use a speaker that can do double-duty as the HF side of a biamped rig.

Your suggestion is a more conventional approach to a rehearsal amp. An even more conventional approach would be a 12+6, and a 12 sub. But the OP is currently rehearsing with an 8" studio monitor, and it's adequate (my kind of rehearsal, BTW). He doesn't need a 12" woofer.

 

[Passinwind]

It just seems like so many people feel that this is such a terrible idea. I don't understand. I'm not straying from fearful design.

I love the concept, and I came close to doing one that way myself before another much easier option presented itself. To stay true to the fEARful design you absolutely must stick with one of the 6.5 inch drivers though, and the woofer has to be directly underneath the mid driver and tweeter. The mid and tweet need to be as close as possible to the woofer too. My suggestion would be to build the "standard" top box and go ahead and mount your amp in there too. Use whatever you decide on for your practice rig underneath, a separate small 8 or 10 cab or whatever. To me it makes no sense to carry around an unused woofer to gigs. Any 8 or 10 that makes enough low end to really keep the fEARful feel will most likely not do the distortion tricks the 6ND/NM 410 is so good at, nor will it disperse as well or crossover to the tweeter as gracefully at the high frequency the CBG crossover is spec'ed at. If you're looking at a clean slate design, that's another can o' worms.

BTW, AccuGroove uses a ported mid driver chamber in at least some of their cabs. I don't have mine anymore, so I can't do any of the measurements that might prove instructive.

Best of luck, and have fun.

 

[MWBass]

Passinwind...

I hear what your sayin. I ended up deciding that when the time is right, the headcase/combo thinger will include the 18 Sound ND410 Driver in a sealed chamber of appropriate volume. So, when it is set atop the 1212sub, it will be full Fearful design.

In combo amp mode, the extra woofer will be in a chamber of my own design. I did my best to read these threads, analyse the fearful design, use WinISD Pro and slightly hope for the best. As I said, i don't mind experimenting a little in the little combo amp side, since it will just be a small practice amp. When it comes to the full rig, it will be in Fearful form.

Your suggestion about the mid driver being aligned above the woofer, and not to far separated, sparked a redesign of my concept. It looks pretty awesome. However, in the design, there would be no crossovers. I think you are one of the guys that builds his own crossovers. I'll explain. I decided to forgo the tweeter, which allowed me to bring the box size down by almost 25%. This brought the internal volume for the woofer section to the correct volume with no left over space. (unlike the original design which had some extra useless cavity space outside the woofer and midrange enclosures.) Now the combo would be about the size of a typical small box neo 112. I would be powering the combo and full rig through an Eden WTX1000 powered navigator head, or a Carvin BX1500, which are the only two amps that have shallow depth, 12" or under, fairly light weight, 11 lbs., and have biamping with built in crossover adjustment.

 

[Passinwind]

Cool, glad I could help a little. Sounds like you have thought things out pretty well at this point.

I do design and build my own passive crossovers sometimes (don't try this at home, allsimsayin'), but I also biamp a lot of the time and also get to "enjoy" arcane DSP programming as a consequence.

I've heard 4Mal's 12/6 biamped with his Eden WT-800. That works very well, so I assume your rig will sound great too.

 

[1n3]

MWBass - It sounds like you've developed some pretty specific ideas. If I understand it correctly, your headcase will now have the 18 Sound mid, and a woofer that will be disconnected when running with the 1212 sub.

By all accounts, the 18 Sound 6ND410 is an impressive mid. If it's important to use that speaker, the rest of my post will be moot for you. But if your goal is only to stick to a pure fEARful design, you could also do that by using two Alpha 6a speakers. Unlike the 6ND410, the Alpha could be used full-range at low volume. The bass output would not be impressive, but you wouldn't have a "dead" speaker at your gigs, cost would be lower, and you'd have room for your tweeter again.