Dayton Series II and Pioneer 8" fullrange idea

[acoustixman]

I'm am already about to order the Dayton Classic 6.5 and some Audax tweeters to do an upgrade on some nice sealed boxes at my house. These drivers seem to model well with the box. (Plus, the Classics are on sale. )

I could get some extra 6.5's and go ahead do a full Classic 3-way. Dayton 10, 6.5, and the Dayton silk tweeter.

EXCELLENT CHOICE! My Dayton 10's were under the Classic 5.25's and the titanium 1". Probably pretty similar except your plan would almost surely yield more power capability.

If I really wanted to, I could get some extra thump by running 2 Dayton 10"s similar to this PE project http://www.partsexpress.com/projectshowcase/veritas.htm
He's getting in room bass into the 30's from a sealed enclosure.
This plan would give me a smaller box than I originally was going to do.

I was considering getting the Dayton 3-way x-overs, since they are on sale. But I wonder if it's better to setup a 1st order 6b setup. Then I could run everything and end up with about an 8ohm load.

Any thoughts?

The (blue-board) Dayton XOs are good. I've used one of the 2-ways. As mentioned the 12dB XOs are more predictable without driver compensations. Impedance will end up flatter too. I've used one of the cheap Dayton 3-way 12dB XOs too, but not quite as crisp sound as those blue Linkwitz-Riley ones. You'd be very happy with them. I'd rather have a relatively flat 5 or 6-ohm average (and usually do) than a highly reactive 8-ohm average. The only way to do better than those blue L-R 12dB XOs is to design it yourself piecewise on a simulator (IMO).

edit: fixed quote syntax

 

[acoustixman]

Note: The steeper the XO slopes, the higher the power throughput. Bear in mind that half the power is below ~350Hz too.

 

[prerunnerv6]

EXCELLENT CHOICE! My Dayton 10's were under the Classic 5.25's and the titanium 1". Probably pretty similar except your plan would almost surely yield more power capability.

edit: fixed quote syntax

This is coming together nicely. The more I think about it, the more I like the idea of the full 3-way setup. I also like the fact that their sensitivity ratings are almost the same.

Good to hear about the x-overs. I'm currently using their 2-way version and hoped the 3-way would work as well. I'm thinking that this one would be best for my setup.

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=260-150


1. Now, the x-over has a 4ohm setting for the woofer. If I did run 2 Dayton's in parallel and used the 4ohm setting, how much trouble will I give my amp/receiver?

2. Is it best to internally sepaprate the mid from the woofer in this 3-way setup? If I do 2 woofers, should I still separate all of the drivers (minus the tweeter)?

 

[acoustixman]

1. Now, the x-over has a 4ohm setting for the woofer. If I did run 2 Dayton's in parallel and used the 4ohm setting, how much trouble will I give my amp/receiver?

2. Is it best to internally sepaprate the mid from the woofer in this 3-way setup? If I do 2 woofers, should I still separate all of the drivers (minus the tweeter)?

1) This 4-ohm setting basically aligns a second-order filter for specified Q characteristics. I think Dayton's whole idea of it is actually to cater to having 2 woofers in parallel. It's not hard-and-fast that you must use this setting for nominal 4-ohm drivers, but the choice of wiring the woofers in parallel and setting it for 4-ohm is definitely the best starting point. In general, the lower the driver impedance is relative to the filter specification, the lower the Q (better transient response - make your eyes blink when you listen to, say, Fleetwood Mac's Tusk album...) but also the lower the power rating / efficiency (I always choose transient response over efficiency, which will likely be different for a PA-er). Believe it or not, this won't affect the actual impedance minimum, just the low-pass filter slope profile.

I think most amps will handle a bit of low impedance better than they handle high reactance (current flow not in sync with music voltage). Still, use with care if hooking multipe speaker systems to single amp. Still though the portion of the frequency spectrum where your speakers will demonstrate 4-ohm impedance will be pretty small, probably around 80-120 Hz, and that's only a portion of the amp's concern. Each crossover point places an impedance peak, between which it falls down near the impedance of the driver in question.

For the heck of it, I'm attaching the {SIMULATED} impedance response of the system on which I'm currently working. It's a 4-ohm woofer. The purple line is the woofer with compensation applied (two resonance peaks are artifact of ported alignment; port controls cone excursion at the ), green=midrange likewise, red=tweeter, blue=system. I'm calling this a 6-ohm system (it should say "ohms" instead of "volts" on left). I'm not going to spend a minute worrying about my amp's ability to handle this load. Note that the driver curve upper ends are flat. That is through the use of Zobel networks (R+C in series, hooked in parallel to driver terminals). Also, I like to give each driver a little resistive shunt (20-50 ohm) to dull-down the resonance peaks, acting like shock absorbers a car. They decrease efficiency (and as a matter of fact they reduce the total impedance) but the "ride" is oh-so-nice! This is about as flat as you can get impedance without resonance compensation, which can be very risky without verified driver measurements, since if your target frequency is off-kilter, you create a second ripple instead of reducing the first.

2) I would always internally separate off-band drivers (mid from woofer, etc.) to prevent crosstalk (the woofer(s) could intermodulate upon the midrange by periodically pushing the coil partly out-of-gap and it gets compressed). In the case of 2 woofers, on-band and hooked in electrical unison (+ to +, - to -), let them work together in one airspace. The parallel wiring (nil source impedance differences) will constrain them to equal activity.

Yours will be a formidable system!

 

[prerunnerv6]

Your system is going to be incredible! Please post your results when you are finished.

I think I've got everything I need to go forward. Just one more question I think.

I was going to go with the Dayton 3-way x-over that is 375/3000. The Dayton 6.5 unshielded has a dip about 3,000...whereas the shielded version is still good at 3,000. But it's only 1db less efficient.

Would the unshielded still be ok or should I just go for the shielded?

Unshielded: http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=295-305

Shielded: http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=295-306

And I assume that the tweeter is fine in the same enclosure as the mid driver. Correct?

 

[prerunnerv6]

By the way, where do you get your caps and coils from?

I want to make a simple 6db x-over for my PA box and use the Dayton 2-way x-overs I have for my Dayton 6.5 upgrade. But, the coils cost about almost as much as just buying a whole Dayton x-over.

Am I looking at the wrong thing? Is the coil for a 2000-2500 lowpass really nearly $14.

 

[acoustixman]

Please post your results when you are finished.

Likewise!

I was going to go with the Dayton 3-way x-over that is 375/3000. The Dayton 6.5 unshielded has a dip about 3,000...whereas the shielded version is still good at 3,000. But it's only 1db less efficient.

Would the unshielded still be ok or should I just go for the shielded?

Probably a good choice on the XO. Depending on the tweeter, you could probably go a little lower on the high end (the Vifa I mentioned can easily do 2kHz), but you won't have any difficulty where you're suggesting. I think you'll appreciate the off-axis delivery even at the 3kHz point...

Personally I'd go for the unshielded unless it's going to be by a CRT monitor or TV set... I'm (perhaps superstitiously) afraid the magnet gap is altered by the additional magnet. Certainly a matter of opinion. I wouldn't sweat that 3kHz drop (I looked at the graphs). I think there are enough other variables that it could be an artifact of the test setup. You'll be down 6dB there anyway.

And I assume that the tweeter is fine in the same enclosure as the mid driver. Correct?

I always have. Particularly if the tweeters provide a rear chamber like my favorite Vifas ... How about the Audax's you're looking at? What's the P# on those?

 

[acoustixman]

By the way, where do you get your caps and coils from?

I want to make a simple 6db x-over for my PA box and use the Dayton 2-way x-overs I have for my Dayton 6.5 upgrade. But, the coils cost about almost as much as just buying a whole Dayton x-over.

Am I looking at the wrong thing? Is the coil for a 2000-2500 lowpass really nearly $14.

Nah. If you wanna get those "foil-wrap" or "perfect layer" inductors, maybe. I've never thought my inductors were the last thing limiting speaker performance though. Assuming 6 ohms, (inductor varies with the ohms given frequency), at 2387Hz, (-3dB point for FOXO) 2*pi*f*L = R... L= 0.40 mH...

I get my caps and coils from either Madisound (http://www.madisound.com/) or PE.

For inductors I always use the basic air-core units (Madisound has nice plastic-bobbin ones; "standard air core"), 16 guage is nice (lower series ohms) but 18-19 does OK. Try to avoid 20-ga or thinner. That 0.4 mH (19ga.) from Madisound is $2.55. (http://www.madisound.com/cgi-bin/index.cgi?exact_match=yes&product=L19&cart_id=8856312.12379)
From PE its $2.92 (18ga. but without bobbin) (http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=255-224&DID=7)

For caps over 20uF I use bipolar electrolytics + 1uF metallized film in parallel. Under 20uF I use metallized film for value, often with 0.1uF in parallel. I have heard some people gripe about resonance issues arising with these two types of caps and parasitic inductances, but my ~20uF rule (softly enforced ) keeps the electrolytics in the low-pass section (more strictly enforced ) I think it's more important to give the electrolytics a little bypass since they have higher series resistance than the poly's. I again go with budget: Bennic if from Madisound or Dayton if from PE.

 

[prerunnerv6]

I always have. Particularly if the tweeters provide a rear chamber like my favorite Vifas ... How about the Audax's you're looking at? What's the P# on those?

Here's the Audax tweeter.

http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=276-152&scqty=2

 

[acoustixman]

This looks like a very decent driver, particularly for the $$. Most of the Audax tweeters have always looked pretty good to me.

The suspensions on tweeters generally don't allow much motion (and thus provide an inherent measure of excursion / intermodulation protection)... It's hard to say on the isolation. The cleanest and baddest approach would be to isolate it inside, but I think you have less to worry about than between woofers and midranges cuz of the tighter suspension... I have not always used self-contained tweeters. No problems yet. For the trouble I'd probably skip it, except that you can find little plastic cups for this purpose... little hole for the wires; mounts to inside of baffle; no major added woodwork... I was thinking I'd try these next time I use a non-self-contatined tweeter.

btw, I generally try to get the tweeter and midrange as close as possible (to each other pysically) in the baffle... This improves off-axis response and large-space control of the completed system. It provides added resemblance to point-sourcing at the XO frequency.

 

[prerunnerv6]

acoustixman,

I crunched some more numbers. Your suggestion to go with a 12" woofer is valid. It looks like one Dayton Classic 12" will only give me almost the same SPL as two Dayton 10"s in a similar sized box.

So I'm now leaning towared not going with the two Dayton 10's and will probably do the Dayton 12/6/tweeter 3-way using the Dayton 3-way x-over for 375/3000hz. A 150 watts should bring that setup to life. And it will be less board cutting.

I would then leave my current Dayton 10" in my PA box, since it is still working well. (I just need to tone down the tweeter horn and put a high pass cap on the mid for greater protection at high volume. ) And if I play it with the Dayton 3-way, that should give me considerable output.

If I go this route, it may save me about $80 and still get the same results I want.

Any further thoughts would be welcome.

Also, if I have say a 102db tweeter/mid and a 89db woofer...what resistor value do I use to tone the tweeter down? Or is a variable resistor the best way to go?

Thanks.

 

[acoustixman]

Your current plan is just about identical to mine. I have high hopes that they will both kick some !@$$!. Just make sure you give that Dayton 12 enough volume. If you put it into 85-100 liters and tune it to 25-30 Hz, it will be a real banger. I'd personally favor 100L at 28Hz for deepest bass while still providing a good non-booming transient response. That's still less volume than two 10's, and a little more bass extension too... I'm only not using the classic 12 since I'm kind of tied to 72-liter cabinets, and that's without subtracting my midrange isolation. I'd use the Classic 10 but the hole's already cut of course on these old boxes.

I'd probably get one of their L-pads (PE). That's quite a cut (~-13dB), and possibly hard to predict dead-on. The http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=260-255 from PE is pretty good. Just don't put the knob on till you're done installing. I made that mistake on one of these and the knob stuck so well that its removal tore the L-pad right apart and it was trashed . Where they say "constant 8-ohm impedance" does belong in quotes, but the more you turn it down, the more true this will be, and in your case it should be good. The means of always-available adjustment is nice too.

Just in case, assuming the tweeter is 8-ohms and the XO is setup for 8 ohms (I think those Daytons are) the exact resistors (for -13dB) would be 6.2 ohms in parallel and 2.3 ohm in series. You could pull it off with 6 ohms in parallel and 2.5 ohms in series to use stock items but I'd still use the L-pad. The -13dB figure could be different than what you end up really wanting...

 

[prerunnerv6]

I wrote the previous post before I read your last one...

2) If you are truly set on the Dayton 10, I'd place one in 65L ported box, tuned to 38-40Hz (or two in 130L likewise gets you +3dB, but quite high port velocity / noise if not huge (doesn't count towards box volume)). Put the Pioneer in 12-20L sealed volume, XO at 4-500Hz.



Am I still helping at all?

Just to cover all of my bases before I hit the "Purchase" button on the computer, let me revisit your statment here and touch on your last post.

I ran some #'s and what I'm getting is that two Dayton 10" Classics come out nearly the same as the one 12" Classic...in SPL and bass extension. Now using a Pioneer 8" FR and one 10" may not be worth it? But could using two 10" Classics w/ the Pioneer 8" FR be more of a match? Since it would be like using an 12" and 8".

Two 10" sealed is 61.7 liters volume to get .72 Qtc. One 12" sealed needs 53.8 liters to get .71 Qtc. So in box building, I'm not looking at a huge difference.

I'm sort of in your position. Trying to make use of what I have and go from there. If I still order a 2nd 10" to go with my current 10", I could use two 10" x-over at 400hz....then the Pioneer 8"+Piezo (or any other tweeter I have laying around at home).

This may be the best compromise of SQ and still be able to compliment my PA boxes in a smaller venue.

I do love the sound of a Classic 3-way setup, but this way may come out well for less $$$ as I will spend less money on drivers and crossover componets.

Thoughts?

 

[prerunnerv6]

Here's a coil question.

If I get a coil to lowpass the Dayton 10"s and I run them in parallel for a 4ohm load....should I get a coil value for a 4-ohm load and run both woofers through it....or do I get two 8-ohm coil values and put them on each woofer?

 

[acoustixman]

Here's a coil question.

If I get a coil to lowpass the Dayton 10"s and I run them in parallel for a 4ohm load....should I get a coil value for a 4-ohm load and run both woofers through it....or do I get two 8-ohm coil values and put them on each woofer?

I'll go for the easy question first. With multiple drivers (especially in the same air volume) you want to keep them coupled with minimal "mutual" source impedance (impedance between them)... That is, hook them right together in parallel and filter as a single 4-ohm (or more specifically half-impedance at frequency of interest) unit... Otherwise, you can introduce electrical decoupling and raise the reactive order of the system. The amplifier would be less apt to control the woofers at resonances, (resonances= both inherent and contrived by decoupling filtering circuit)...

Here's a marginally-applicable analogy: Picture a car in transit on a soft-sprung flatbed trailer; the car's motion has less direct response to the bumps than if it were riding on the ground itself. The bumps would represent your music source and the car would represent the woofer. It's actually a better analogy for a reflex alignment where the car is the port and the trailer is the woofer, but similar thinking applies.

More on your other thoughts shortly... I need to look busy for a few...

 

[acoustixman]

Just to cover all of my bases before I hit the "Purchase" button on the computer, let me revisit your statment here and touch on your last post.

I ran some #'s and what I'm getting is that two Dayton 10" Classics come out nearly the same as the one 12" Classic...in SPL and bass extension. Now using a Pioneer 8" FR and one 10" may not be worth it? But could using two 10" Classics w/ the Pioneer 8" FR be more of a match? Since it would be like using an 12" and 8".

Two 10" sealed is 61.7 liters volume to get .72 Qtc. One 12" sealed needs 53.8 liters to get .71 Qtc. So in box building, I'm not looking at a huge difference.

I'm sort of in your position. Trying to make use of what I have and go from there. If I still order a 2nd 10" to go with my current 10", I could use two 10" x-over at 400hz....then the Pioneer 8"+Piezo (or any other tweeter I have laying around at home).

This may be the best compromise of SQ and still be able to compliment my PA boxes in a smaller venue.

I do love the sound of a Classic 3-way setup, but this way may come out well for less $$$ as I will spend less money on drivers and crossover componets.

I'm having a difficult-ish time visualizing what you already have to start with... My current visualization is that you have a PA setup with the Dayton C-10's in it and you're thinking about replacing them with something else and buying 2 more C-10's OR leaving them in place and using C-12's instead... On the midrange, you are deciding whether to use the pioneer 8" full range or Dayton C-6.5. In the case of the tweeters, you are pondering Piezo horns vs. Audax domes...

The Dayton 6.5" mid-bass drivers are quite capable. I have used them in 2-way systems as the low end. The pioneer FR drivers will offer deeper bass extension, but you are considering them only as a midrange. I would choose the Dayton 6.5, since as [rather stiff-coned] midranges they offer better HF extension.

The Audax tweeters present a very decent HF alternative. I favor the use of dynamic dome tweeters personally, but the piezo driver is probably an interchangable unit, especially since it becomes a resistive load when paralleled with an 8-ohm resistor as is typical implementation. The piezo tweeter lacks a voice coil, and is thus immune to intermodulation due to being contained in the same air volume as either the woofer or midrange...

On the woofers, if I have correctly interpreted your situation, I would do as you have suggested and leave the Dayton 10 where it is. Either the Dayton 6.5 (my choice) or the Pioneer FR-8 will XO nicely into the 12, which would be my choice. The 12 is rated 3dB more sensitive than the 10, which means it is equal to 2 10's. (doubling the number of drivers = doubling power = +3dB). The implementation is simpler (1 woofer hole per box instead of 2), the impedance is consistent (all things equal you might as well have all 8-ohm nominal ratings), and the radiating element is more point-like at the low XO frequency (circumference of 12" compares to circumference of 10" plus separation distance between 10's). -- definite plus.

I don't mean to press my attitude, but I think you'd be happiest with either HFD (Audax OR piezo +8ohm shunt), the Dayton 6.5 mid, and the Dayton 12 LFD (as "Occam's Razor" suggests the simplest answer is the most likely...). If you have a pair of Dayton 10's looking for use, you could buy another pair and consider 2 of those roughly equivalent to one of the 12's, but setup your XO for a 4-ohm woofer with them wired in parallel.

Does this help??

 

[prerunnerv6]

acoustixman,

You have summed up my situation nicely. I don't think you are pushing any "attitude" at all. I'm throwing 50 scenarios at you and you've answered them all, and it's appreciated.

Let me possibly fill in the blanks. Because I may have 3 projects going on and I may keep mixing them into the same scenario, which can be confusing. I apologize.

1. I AM going to do a 2-way setup with the Dayton 6.5. So that's a done deal. I'm doing what you are doing, retrofitting some existing boxes. I'm going to use the Dayton (blue) crossovers, which I already have. My only question on that was whether to use the Dayton 1 1/8" silk tweeter and have an all Dayton...or try the Audax tweeter. The Audax tweeter is almost a drop in fit for my application. The Dayton silk will require some box modification, but it can cross lower than the Audax. I'm using a 2,000 hz x-over, so the Dayton looks like it would be worth the modification. (So that's one project.)

2. The second project is the PA system. I currently have Dayton Classic 10's in PA boxes. I was going to replace them, because the horn tweeter wasn't matching well. I was going to get some TRUE Pioneer PA speakers. But you helped me on this earlier. I can just get an L-pad and wire it into the tweeter. I can put a high pass 50hz cap on the woofer to help protect it more and I may be good with keeping the Dayton 10. The Pioneer PA speaker had higher sensitivity, but since I will be running other speakers with this PA setup, I can make up for the SPL by sheer # of speakers.

3. The third, and IMO, final project is what to use to COMPLIMENT the PA boxes but still sound good in my home. The reason I was going to go with the Pioneer 8" FR and the Dayton 12" is because it seemed like they would be louder than the Dayton 12/6/tweeter 3-way....at least according to my calculations. Yet, still give good SQ for the money and with minimal x-over components. I could be wrong. I have no doubt that the 3-way setup will have the best SQ, but it may fall a few db's behind in the SPL I need to compliment the PA boxes.

Also, with the Pioneer 8", I'm not locking into one configuration. A friend suggested building two enclosures for the 12" and 8" and stack them. Instead of a 400hz x-over point maybe let the 8" drop down into 200hz range and let the 12' stay in it's most comfortable area. Thoughts? Would you still recommend 400 hz x-over as optimal?

Thus I come back to which is the better 12" driver? The Classic 12", the Series II, Quatro 12. Classic and Series II are about 92db sensitivity. The Quatro is 90db. But the Series and Quatro has twice the x-max and over 3 times the power handling. But the graphs show that the Classic STILL has more bass extension. And it cost less than half. My only concern is the power handling. But I've always thought is was better to overpower speakers (within reason) than underpower them. The Quatro and Series II would be underpowered.

So that's where I'm at. You've pretty much helped me resolve projects 1 and 2. Project 3 is the one I'm at now. Thanks. You are helping me out a lot.

I hope I made things clearer this time.

 

[acoustixman]

1. I AM going to do a 2-way setup with the Dayton 6.5. So that's a done deal. *snip*

Gotcha. Good system with either tweeter.

2. The second project is the PA system. *snip* I can just get an L-pad and wire it into the tweeter.

That's what I'd do.

3. The third, and IMO, final project is what to use to COMPLIMENT the PA boxes but still sound good in my home. The reason I was going to go with the Pioneer 8" FR and the Dayton 12" is because it seemed like they would be louder than the Dayton 12/6/tweeter 3-way....at least according to my calculations. Yet, still give good SQ for the money and with minimal x-over components. I could be wrong. I have no doubt that the 3-way setup will have the best SQ, but it may fall a few db's behind in the SPL I need to compliment the PA boxes.

Also, with the Pioneer 8", I'm not locking into one configuration. A friend suggested building two enclosures for the 12" and 8" and stack them. Instead of a 400hz x-over point maybe let the 8" drop down into 200hz range and let the 12' stay in it's most comfortable area. Thoughts? Would you still recommend 400 hz x-over as optimal?

If you wanted a sub-sattelite system; do this with 12's in their own box. Setup frequencies the way you suggest. You might consider the FR 8's in their own box like this, but SEALED for transient response, and bass roll-off. Tweeters to "taste". Meanwhile, consider putting the 12" into a bandpass box (one side of driver sealed, other side ported, driver not ultimately visible). This is a flexible alignment, which rolls the woofer off on the high end (functioning as an "acoustic crossover") where that tight, sealed FR 8 takes over. You might want to bi-amp this kind of setup, but You could get away with it without. I have never made a BP setup... I would expect it to be a little boomy for my tastes... I'd do something like this if my primary goal were "home theater".

If you wanted to have a killer three-way system instead of sub-sats, here's where I'd use a Dayton 12, a Dayton 6.5, and a good tweeter (why not the same one as in #1). The top two drivers obviously closely resemble system #1 when you ignore the 12, but this 6.5" used as a mid should be in a small sealed volume (you might be using a ported 18-22L cab for bandwidth in system #1? - I did) of its own (with tweeter is probably OK). If I made a 3-way out of that C-12 woofer, I'd go with a QB3 alignment (close to an octave extra to -3dB vs. sealed but very smooth rolloff), box size maybe 10% smaller than "optimal" ported, box tuning 5Hz below "optimal" fb. This system will BANG (not boom / trudge through the mud), and is easier to XO, just use one of those blue-board 3-ways, and mono-amp per channel. Sensitivity of the MFD ends up being a small priority. I've had to attenuate LESS sensitive mids in 3-ways. I'd do something more like this (and generally do) if my primary goal were hi-fi music audition (which it almost always is in my case). This would surely make you happy for a long time to come.

Thus I come back to which is the better 12" driver? The Classic 12", the Series II, Quatro 12. Classic and Series II are about 92db sensitivity. The Quatro is 90db. But the Series and Quatro has twice the x-max and over 3 times the power handling. But the graphs show that the Classic STILL has more bass extension. And it cost less than half. My only concern is the power handling. But I've always thought is was better to overpower speakers (within reason) than underpower them. The Quatro and Series II would be underpowered.

Thanks.

No problem at all.

The box size is the biggest (pun NOT intended; well I guess maybe it is) thing I'd look at. If you use system #3 for PA, either outdoors or in large venues, consider the higher powered woofers simply because you need a little brute force on your side, and make cabinet size your second priority. I think it could be a waste of effort to build these to "supplement" system #2 if you wouldn't be prepared to rely on them solely. The single-boxed 3-way I suggest would be your easiest alternative in terms of transport and hookup/XO, and the 2 main reasons for it to be ported are personal taste and higher SPL/efficiency. The Quattro is more expensive due mostly to the higher Xmax (suspension and motor systems are made to be extra-groovy), which you don't really need in a properly aligned ported system (if you're spinning vinyl, use a high pass filter maybe an octave below box tuning - cartridge preamp probably includes this). The cone excursion increases with sealed alignments, and that's where the Xmax pays off. 3 times the power handling equals about +4.8dB (only shows up when cranked). Sensitivity will keep it (and your amp) cooler, and bass extension will keep YOU cooler .

Well I'd better get to the office...

 

[prerunnerv6]

You've sold me, acoustixman.

I can't refute your logic. My original plan was to build something that would be at least as good as the Cerwin Vega's I looked at...and your plan seems to meet that critieria.

So I'm going to go with the Classic 3-way....12/6.5/tweeter. I'll use the Dayton (blue) XO's for 375/3,000hz. I'm going to PORT the 12" going slightly smaller as you suggested.

The figures I come up with are I could have a 14x42x14 box. (For transport reasons, I'm trying to top it off at 42" high. I will probably put recessed handls into the cabinets.) If I dedicate 78 liters to the PORTED 12", tuned to 30.5hz, this will give me some relatively flat response and good bass without over-excursion of the Classic 12". The port would be 4" diameter and 10" long....front firing.

The remaining .9 liters SEALED would go to the 6.5 and tweeter. Normally, this is too large for the 6.5, but at the 375hz x-over point, I should be fine.

This setup could stand on it's own if need be. And as you say, will give me good SPL and Hi-fi SQ.

See anything I missed or something I didn't understand? I'll be putting in my order today. Thanks.

(My measurements are based upon 3/4" board. I may go w/ 1/2" if it's sufficent...to shave off a few pounds for transport.)

CORRECTION: The box would be 14x42x15. There would be 85.5 liters for the Dayton 12".

 

[acoustixman]

I hope you like it the way you do it. I'm sure I would from the "sounds" of it.

"Too large" on the midrange volume is a good thing. It will subdue resonance all the more and keep it out of filter (XO) range. There would be no harm in giving some of this back to the 12 (It would love to have 90-95 liters but will happily survive on 85; the box isn't "too big" until over 100 liters for that driver IMO), provided you keep the 6.5 Qtc at or below 0.707 (personal rule of thumb for midranges - lower the better).

Your plan of a 4" port is a good one. I have seen plenty of front-firing ports, but I have always placed mine down low and in the rear. I can hear them "talk" a little less that way. As tubes they can pick up slight midrange artifacts from the woofer and resonate a little. I have never heard them do this when the port is facing elsewhere, even to a hard wall. Again, either way will provide enjoyment; don't let me be a pain in the butt... You can get that port quiet and also simulate more box volume with a small bit of stuffing in the box (don't pack it, just kind of line it). I have used even just a small piece of fiberglass insulation in the bottom for this. Just don't fill or obscure the port with it.

I would definitely stick with the 3/4" panel stock. Some folks think that's not even enough for the front baffle, but I have always used it. 1/2" will tend to radiate coloring sound by allowing itself to get excited by driver motion.

Try fooling with port length (particularly longer for lower box tuning frequency). The longer it is, the more the alignment behaves like sealed (tighter and tighter bass, but less SPL). You might try plugging it altogether for a "home Hi-Fi mode".