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$2000 for 4 drivers, what would you do? Details inside. - Page 2

post #31 of 90
Thread Starter 
Hey Scott, Omega

I’m thinking robust 18s as well.

Is the Fi SP4 my best available option? The Aurasound NS18-992-4A looks cool, but they’re almost twice the price. Neodymium magnet must be to blame.

Here’s a little back story and a diagram for mounting plates that I posted on another site.

"Admittedly I initially went with 21s for pure musical output, and now that I'm faced with the prospect of smaller drivers my limited understanding is defaulting to: smaller driver, same quantity, less output. What I'm not keeping in mind is how much better EITHER of these drivers are than my current 21s.

You are the experts and I need to listen. It was my limited knowledge that started this predicament to begin with. Bigger isn't always better.

Here's a plan for modified mounting plates for 18s. Perhaps you can tell me what you think. My initial idea was two 3/4 Baltic birch sheets laminated, glued, and screwed."

post #32 of 90
I wouldn't bother with that. I'd just have a single piece mdf/baltic birch panel (or a couple laminated) with the correct cutout size on that and then glue, screw or nail that right over the existing cutout for your 21"er.

The Aurasound 18 is a really sweet driver but might be a bit expensive. Also, it's limited in output by throw and thermal handling. It uses a smaller, underhung type voicecoil system and is probably best to use not much more than 1kw per driver. The Fi SP4 on the other hand is a SPL monster that was made to take a lot of power. Both are very different and not really comparable. However, you could get two SP4's for the price of the Aura (unless someone knows a good source).

What I'd suggest is to gut (and replate) just one of your enclosures when you're about ready for this and picked a driver. Order two of that driver and test fit and see how you like the sound and bass from that. That is unless you're completely ready to dump your current 21's but I'd bet they have good midbass that you could end up missing with new, high excursion subs. Just a thought.
post #33 of 90
Thread Starter 
The only concern I have about plating over the existing cut-outs is that the down firing drivers have about 8" of clearance. Would it hurt to subtract from that? Well, also that the cabinets are already HUGE. If I can avoid making them bulkier with a bit more work I'm willing to do that.

The thought of picking up two drivers for now is interesting.
post #34 of 90
Oh yeah, well... some of these drivers need a bit of clearance to fit in a box with bracing. I believe most 18's will need around 10" at least. Possibly more for the SP4 as it is a pretty deep design.

I saw you posted in Wi's thread and you saw how he did the 21"->18" plate for his. Just do the same thing or add thickness with an additional layer if you want. Sure won't hurt to do so.

Gonna need some good pics with some measurements of the inside of your cabs to know if you can fit larger (deeper) drives in them. I don't think it would hurt to get the saw to the bracing if you needed to.
post #35 of 90
I think hes saying down firing = 8" from the floor
post #36 of 90
Oh. Then there shouldn't be an issues.
post #37 of 90
Thread Starter 
There's actually no cross bracing. In the picture below you can see bracing in the corners and vertical axis's. There are three of these "rings" on the vertical axis's rounding the perimeter.

The SP4s look to draw 11.75" of mounting depth. The enclosures are 36" tall OD, so I think there's plenty of vertical space for both drivers motor to motor.

post #38 of 90
Yup. You're good to go. Just need to make a few new mounting plates for the new drivers, which ever ones you pick.
post #39 of 90
Thread Starter 
Fun stuff, fun stuff!

Would a fair assessment be that the B&Cs are a better music woofer, and that the SP4s are a better HT sub-woofer? (Given my enclosures)
post #40 of 90
Okay, just to be clear, there is no for sure answer to that.

That being said... I would say that they would simply because they are much more sensitive in the 40hz and up frequencies and may very well have little inductance related top end rolloff. The Fi SP4 may have that. The B&C was made to be used in bass cabs for concerts, DJ gigs, cinema use so you should expect good performance up there. Also, it has a huge 6" voicecoil and probably less likely to thermally compress in the higher frequencies where most sub/bass systems are power limited. This is why I thought you should two of your current 21's running so you can have some of that midbass still going. It's really up to you though on how you want to do this. I just thought it would be good to try cuz it would save you some money and if you are fine with dual high excursion 18's then that's one less box to work on.
post #41 of 90
Quote:
Originally Posted by pwz414 View Post

Fun stuff, fun stuff!

Would a fair assessment be that the B&Cs are a better music woofer, and that the SP4s are a better HT sub-woofer? (Given my enclosures)

I guess you could say something like that.

At 30-35Hz and above the B&C's are going to eat most other woofers for lunch one on one, save for a few other also very expensive models. To say they will get loud is an understatement. I wouldn't be surprised if it was 6dB more efficient than the SP4 at 80Hz. The ones it won't are also pro woofers. Below 30Hz it can do a decent job because of the huge SD, but it doesn't have the extreme displacement like the 30mm xmax 18's (Like the SP4), so those will win the headroom race there. If you need to go deep with a pro woofer it is better to horn load it or port it to keep the excursion in check.

You should define what improvement you want out of your bass system and then pick a driver that targets that area best.

Also your enclosure is far bigger than needed to run any pro woofer sealed. They have powerful motors and don't need a lot of enclosure volume. 14cubes is plenty for multiple big woofers sealed or one big ported cab tuned low.
post #42 of 90
Perfectly sized for dual opposed SP4's!

Like Ricci said (and I mentioned earlier) you would have to decide where you need more of wrt bass. Is it more punch and slam? Which you probably have lot's of. Or more deep bass, which it sounds like you want. For that you need displacement and lots of it.
post #43 of 90
Thread Starter 
Yep yep, I'm picking up what you're laying down.

I need to pick what the system will be more inclined to do. I'm leaning towards music for my own selfish reasons

Here are my options: easiest to most difficult. The ratios are guesses based on the little I’ve learned since registering. Feel free to correct me.

Option a. 4 B&Cs 8ohm 4.5" coil, sealed, dual opposed, down/up firing.
80 MUSIC/20 HT

Option b. 4 SP4s or "like" 18s, sealed, dual opposed, down/up firing.
70 HT/30 Music

Option c. 2 B&Cs 4ohm 6" coil, ported. An attempt to "copy" Ricci's system with my own enclosures. Fairly major surgery.
65 Music/35 HT
post #44 of 90
You're using those line array's for you mains, yes?

Option D: Keep everything the same. Add and build four more enclosures (or two dual-opposed) with SP418's and pick up an LG clone amp to power the subs. Ohhh yeah!
post #45 of 90
Thread Starter 
I notice Ricci's ported B&C system positions the driver and the port on the same plane. I imagine that's advantageous.
post #46 of 90
Thread Starter 
Quote:
Originally Posted by Scott Simonian View Post

You're using those line array's for you mains, yes?

Option D: Keep everything the same. Add and build four more enclosures (or two dual-opposed) with SP418's and pick up an LG clone amp to power the subs. Ohhh yeah!

Hahaha I like the way you think, Scott. I seem to remember reducing enclosure footprint being a goal of this operation, but as you can see that's gone by the wayside.

Yes, the lines are the mains. The system was built for music and has a bypass of all the HT electronics built into the High Emotion XO 3. By placing a volume control on the XO 3 it became a separate pre-amp facilitating the bypass of my NAD. The lines are pretty cool. A different kind of loud, very detailed, strong imaging. Unfortunately I've never heard them outside that crappy room One day
post #47 of 90
Thread Starter 
Quote:
Originally Posted by Scott Simonian View Post

You're using those line array's for you mains, yes?

Option D: Keep everything the same. Add and build four more enclosures (or two dual-opposed) with SP418's and pick up an LG clone amp to power the subs. Ohhh yeah!

Here's an idea, build a crossover for my 4 dual opposed 12s to task them with mid-bass, and go the SP4 route for low frequency tasking. Haha, this is getting complicated. I'm just kidding. I really want to keep things simple if possible.
post #48 of 90
The simple one would be to try out two new deep bass drivers and compare them to your 21's using the same amp and in the same enclosures.
post #49 of 90
I'm in a similar dillema. Want 4 18's in dual opposed for low and loud bass. I already have a lg clone, whats the smallest size enclosure you would want to run the sp4 in?
post #50 of 90
Depends but I'd stick with ~4cuft per driver.

Which LG clone amp do you own?
post #51 of 90
Fp14000. Ordering a mini dsp also. Currently have an lms ultra with dual pr's. May or may not sell that.
post #52 of 90
Quote:
Originally Posted by keager View Post

Fp14000. Ordering a mini dsp also. Currently have an lms ultra with dual pr's. May or may not sell that.

I see. Not happy with the PR'd LMS-U, huh?

If you're going to get quad SP418's, go for the dual 1ohm as you can hook two of those up for a 4ohm nominal load per channel and then each driver would get 2,200w. Nice!

Or you know, whatever you want to do.
post #53 of 90
I like the lms, but it drops off quickly below tuning and I have an acoustically terrible living room that I'm confident will greatly benefit from four drivers in two locations pointed in different directions. I could be wrong though.....

Interested in the uxl18, but dont know if I should hold my breath for them.
post #54 of 90
Why not try out your LMS-U sealed?
post #55 of 90
I guess my thinking is that the amp needs to be run stereo so I can eq the channels seperately. I believe I would achieve more spl with the four drivers than the two lms's getting 4400w each. I havent tried the sp4 in winisd yet. Just speculating.
post #56 of 90
They both have similar displacement. Sooo... yes, more drivers would be louder.
post #57 of 90
I havent seen any home theater builds using the SP-4 yet.
post #58 of 90
Thread Starter 
Keager, I'm interested to see what you come up with!
post #59 of 90
Ricci is in the process of testing out 4 18" drivers. I would be curious to see his results in a couple of weeks before committing to a specific driver. I'm favoring the Sundown Zv3 18s, and one is on its way to Ricci for testing and performance confirmation.
post #60 of 90
Thread Starter 
WiSounds, can't wait to see what he comes up with! Also eager to see how your 18sound turns out!

A couple different drivers have come to my attention.

First, the TC lms-u. At over $900 per what could one expect over the SP4? They have a higher xmax, a bigger motor, and superior spider characteristics... Will that translate mainly to higher spl, or should the lms-u sound vastly better?

Also the 18sound 21" looks cool. I guess I'd have to compare my Miscos to the Pyle 21". These are a pretty big step up, huh?

You guys should have known this a while ago. I can't believe I haven't mentioned it. My woofers will be required to run flat up to 120Hz and roll of at 12db per octave. This measure was taken to protect my line arrays during loud music playback and to clean up my mid range. The 80Hz + octave will be critical to me. More so than 20Hz -. :/
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