Current 18" options for LLT-Big Sonotube

[Bill 3]

Ok, my head is spinning on which driver to use. I figure I might as well go with an 18" but some of the more talked about companies only go up to 15". I am currently looking into Mach5audio, FiCarAudio, Sound Splinter, and eD. The Sound Splinter is really above my budget, but it is all about "bang for buck". I would hate to wish I had spent just a little more.

I plan on building a 24"-30" sonotube - possibly two. Power with a Behringer EP2500 - I am hoping it is enough to feed 2. Room is in the basement and approx 15 x 32 x 8 - kind of unusual with a pool table, a bar, and hall (alongside part of it). I have Klipsch reference (RF-7) with KSW-15 woofer. It seems no matter what I build, it will blow the Klipsch sub out of the water - that is if I use the advise given here.

This "sickness" all started when I moved all my "goodies" into this room and wondered what happened to my bass. Bigger room, concrete floor, different style room alltogether I believe has take away a bunch of room gain.

All speaker/driver advise is appreciated while keep trying to learn how to use WinISD and play with Sonosub.exe

Bill

[SteveCallas]

If we say the SS Rlp18 is out of the price range, I like how the FiCar Q18 behaves over the Mach5 IXL18 for just a few dollars more. It will allow you to get away with a better overall design.

[Bill 3]

Thanks for the reply and your opinions Steve. What in this "hobby" isn't out of the price range? I am willing to go for the SS RLp 18 if I can "see" the advantages.

I really started this thread fishing for any other optionns to ad to the mix. Or maybe something new or that I haven't heard about. I did find the Ascendant Audio Havoc 18, but so far, it doesn't model as well. (I am still learning WinISD so I am double checking things).

[Blueeyedfrog]

Acknowledging Steve's comment about overall design, if you plan on getting an EP2500, then I'd go for two sonotubes with the cheaper drivers. That way you're not wasting the power of, and so money invested in, the extra channel - you'll get higher SLPs with two sontubes when compared with one sonotube with a driver with a slightly higher Xmax (so better bang for buck overall). Also, having two sonotubes will allow a broader sweet spot for the listening area meaning a better overall experience for not only you, but also your friends and family (increasing the SAF if applicable). Two sonotubes might also be particularly helpful if you have a non-standard (rectangle) listening room shape, which can sometimes be tricky to get a good sound with only one sub. If you go a different amp and one sonotube, I'd go with Steve's suggestion but if you're comtemplating an EP2500 and 2 sonotubes, go the Mach5s

[Bill 3]

I have put the Mach, SS, and FiCar in a 650 Liter enclosure with 15Hz tune all on the same graph using WinISD. I double checked my input parameters and beleive them to be correct. Now to understand what it is telling me. The SS looks the best. The Mach5 looks better than the FiCar, or am I looking at it wrong?

[thxgoon]

Try adjusting the box for each driver to get the best response curve. They will all behave differently in the same box. The EP2500 should be enough to drive a single 18 and you can always bridge the amp to use both channels.

[mayhem13]

The Mach5 is screaming for more volume in your graphs/model while the RL looks pretty good as is. Don't know what your excursion limits look like though.

[Bill 3]

I was trying to compare driver to driver is why I put them all in the same size box and tune freq.

Would you guys agree that the SS has a near perfect curve in this box and freq? Or do I not understand what the graph is telling me?

Here is the SPL related to the above graph. All at 500W power.

[Mike P.]

Are they within their xmax specs with that volume and input power?

[Bill 3]

Giving 1000 W (800 for mach5). Yes, I believe so

OOPS, nope, the Mach5 only has a 22mm excursion.

[Mike P.]

Different subs model differently due to thier specific parameters. What works for one may not be the best for another. Each sub has it's own requirements for the best combination of box size, tuning, and power input to get the most out of them.

[Bill 3]

Mike P. wrote:

Different subs model differently due to thier specific parameters. What works for one may not be the best for another. Each sub has it's own requirements for the best combination of box size, tuning, and power input to get the most out of them.

I agree. I might not be getting it, but my understanding is that the transfer magnitude graph in WinISD pretty much sums up a driver/box/port combo. It is very difficult to get any of these subs except the SS to behave in a smooth manner no matter the volume when trying to keep the freq at 15Hz or below. Is the "swish" (hill then valley) at the port freq a negative? Is there a better or more accurate representation of how well a driver is suited for a LLT enclosure?

It looks to me that for this price range certain 15's may outperform in a LLT environment.

[Blueeyedfrog]

550 litres is just too big for the Mach5s and yes, the lower peak "swish" is not desirable. Rather, you want a gentle slope which will be boosted to flat, or better, a nice house curve, with the aid of room gain. Steve Callas helped me with the design of my next subs using the Mach5s:

SteveCallas wrote:

IXL 18 doesn't want a huge enclosure, and even at 400+ liters the tuning region starts to get peaky. I like the looks of ~365 liters with a ~15hz tune. You can't get away with an 8" port that way, but since it "only" has a claimed xmax of 22mm, air movement shouldn't be so bad as to cause problems. So it looks like three 4" diameter ports that are each 32" long works best. Two of those and an EP2500 will definitely do the trick. I wouldn't worry about sound quality for one second, as you'll have lots more headroom, lower distortion, much deeper extending FR, and faster overall transient response, all of which work to define accuracy. The most accurate subwoofer doesn't always sound the best subjectively though, based on what you are used to and what kind of music you like. However, over time, for a combination of both music and movies, accuracy tends to win out. A 12" simply can't keep up with two high excursion 18s in LLT form, not by a long shot.

[Bill 3]

I played with the box volumes and have come up with the following. It seems that with price comes performance. And with performance/price comes volume of box for desired low Hz. I believe I understand why Steve likes the Fi over the Mach - SPL. I am still not sure what the Transfer Mag graph is telling me - efficiency???

So the question becomes how much enjoyment is there to be had by having higher output around the tuning point. I guess it is personal preference adn it can always be turned down. This is why it is all up to budget.....

*edit*-I will repost correct graphs.

[thxgoon]

Bill 3 wrote:

So the question becomes how much enjoyment is there to be had by having higher output around the tuning point. I guess it is personal preference adn it can always be turned down. This is why it is all up to budget.....

Isn't it fun

Note that the difference in output between the woofers at 750 watts is only about a db or so. Also, the fi is cruising along at about 20mm excursion out of it's available 27mm, so it still has more to offer.

[Ricci]

Don't forget about the Ascendant Audio Havoc 18!

[Mike P.]

Ricci wrote:

Don't forget about the Ascendant Audio Havoc 18!

I haven't modelled that one yet but I heard it didn't model that well. Have you done any modelling with this one? Just wondering if what was said is true or not.

[Ricci]

It doesn't model as beautifully as the RLP18(which is about as good as we've got right now), but it isn't terrible. The main thing is that you can't really tune it below about 14 or 14.5hz and still get a decent response and it likes big sealed boxes. If you are tuning in the 14.5-17hz area it is decent. 425L tuned to 15hz with an 8" port looks nice to me.

Bill3,
My graphs that I get when modeling these drivers look substantially different than what you've shown.

[Bill 3]

Ricci wrote:

Bill3,
My graphs that I get when modeling these drivers look substantially different than what you've shown.

Well, I have checked and double checked my inputs. I will post up what numbers I use for each driver. I was following the instructions from Collo's page on what to enter.

Qms, Re, Mms, Cms, BL, Sd, Hg, Hc, Pe (But I had to use Xmax in place of Hg,Hc,Pe)

[Bill 3]

FiCarAudio Q18 Dual 2
Qms-5.73
Re- 1.4 Ohm
Mms-342g
Cms-0.13 mm/N
BL - 15.1 N/A
Sd - 1210 cm^2
Xmax - 27mm
Z-4 Ohm

Mach5Audio IXL-18.4
Qms-5.59
Re- 3.4 Ohm
Mms-434.3g
Cms-0.184 mm/N
BL - 20.51
Sd - 1029.2 cm^2
Xmax - 22mm
Z-4 Ohm

SoundSplinter RL-p18 Dual2
Qms-4.535
Re- 3.74 Ohm
Mms-376.7g
Cms-156.7 u
BL - 19.5 T*m
Sd - 0.1188 m^2
Xmax - 27.4mm
Z-4 Ohm

[Blueeyedfrog]

Bill 3

I'm not an expert on this but looking at the graphs you have posted, the RP-L18 and the IXL18 look to have better transfer functions and max SLP curves than the FiCar - that is, if flatter is better. Can someone please explain the impact/relevance of the transfer magnitiude function?

Higher output at tuning just means it's louder down lower (if the tuning is low). As far as I'm aware, most people seem to find a gradual rise in SLP output (in room, not anechoic) as the frequency lowers, to be more pleasing than either flat or dropping SLP - hence the desired house curves many people shoot for with equalisation - check out the BFD forums. Given room gain, the gradual drop-off from the driver/box is compensated by the gradual increase in room gain as the frequency lowers. So less role-off at lower tuning (flatter SLP curves) is usually considered better and so more desirable. By the way, lowering the receiver volume makes the bass drop at lower frequencies more pronounced so if you like to listen at lower listening levels, the higher output at lower frequencies is even more desirable. Hence the loudness buttons fitted on amplifiers years ago, which gave treble/bass boost for when listening at lower volumes.

[Bill 3]

BlueeyedFrog, I like the thought of the higher output at lower frequencies. I like to be able to feel the bass at lower levels. When just hanging out and talking while listening to music and be able to notice the impressive bass without it sounding overbearing would be great.

Ricci, I double checked the numbers I had input for my Fi driver and it appears that I had entered the Fs in the Qms spot (23.8 is a lot different than 5.73) plus I listed the Re as 1.4 where it should have been 2.8 (2 coils).

All of the sudden, I am all over the Fi. It nearly resembles the SS, only better in some areas. Boy does it like volume though. ****, I was hoping to find a driver close to the SS only in a smaller volume so I could use the 24" dia tube.