Help Me Decide Between Two 18” Subs

[jtwrace]

To the OP, you need multiple subs setup properly, not to worry about brand, size etc.

Rythmik Audio Subs or the GSC if you want a diy project will work just fine. The key is multiples setup properly.

 

[voodooless]

From GSG web site FAQ:

How "low" will a driver go?
From time to time we get asked about drivers and cabinets. Frequently, folks see a particular driver specification (such as the driver free-air resonance (Fs), a claim by the manufacturer that the driver is good for a particular range, such as 20-150Hz, or that a driver has a particular -6dB point such as 28Hz) and are led to believe that these numbers determine how low a subwoofer can play in a particular enclosure. This is NOT THE CASE!

When a driver is placed in a cabinet, the two form a *system*. As such, not knowing anything about the cabinet that a driver will be placed in tells us nothing about how the driver is capable of performing.

For the first example, we will use a Dayton UM-18 driver, which is a long-throw, low efficiency (88dB/1w1m), subwoofer with a ton of excursion capability (usable excursion of over 30 mm). It has a free-air resonance (Fs) of 21 Hz. For the second example, we will use a LaVoce SAF184.03 driver, which is a hybrid driver that has medium-high efficiency (95 dB/1w1m) and medium-high excursion capability (usable excursion of approximately 19 mm). It has a free-air resonance (Fs) of 29 Hz.

So which driver “will play lower”, the 21 Hz driver or the 29 Hz driver?

It turns out that when these drivers are placed in a Mini-Marty subwoofer cabinet (which is approximately 7.5 cubic feet of internal volume and tuned to 18Hz), both drivers will have the same low end extension! The picture shows output at a nominal 1,100 watts of power, just for comparison. (Note that frequencies below approximately 16 Hz will be filtered out by the protective high pass.)

At 1,100 watts of power, neither driver exceeds its excursion capability. The LaVoce, however, provides quite a bit more output in the mid-bass region (60-120 Hz). When EQ’d to have the same response as the Dayton, the LaVoce will require quite a bit less power to produce the same amount of mid-bass output. This in turn gives it a subjectively harder-hitting mid-bass.

In summation, be careful when reading about driver parameters, manufacturers’ claims, or folks on the internet stating “how low a driver will go”. In order to know for sure, one has to model it up using the Thiele/Small parameters and for the most part, the enclosure itself is the dominating factor in factor in determining how low a driver will play. Of course, how much usable excursion a driver has is important when selecting an enclosure and an amplifier, as that will ultimately dictate output limits in many cases.

There is zero said about distortion however, and the Ultimax isn’t very well designed for a reflex box, unlike the LaVoce.

When EQ’d to have the same response as the Dayton, the LaVoce will require quite a bit less power to produce the same amount of mid-bass output. This in turn gives it a subjectively harder-hitting mid-bass.

This makes zero sense. Why would that even be? If they have the same response, they will sound the same.

 

[SIY]

Sorry, not following the reference

Iconic marketer in the '70s and '80s. Here's a sample.

 

[levimax]

There is zero said about distortion however, and the Ultimax isn’t very well designed for a reflex box, unlike the LaVoce.

This makes zero sense. Why would that even be? If they have the same response, they will sound the same.

I agree the "harder hitting" thing does not make a lot of sense, also my comments about distortion and x-max also were not correct. I do think that in many applications good "pro drivers" (vs inefficient dedicated sub drivers) with "as much LF extension" and "more" mid-bass output makes for a better solution. At the end of the day what everyone (customers and manufacturers) hates about subwoofers is Hoffman's Iron. For LF extension and high SPL's you need large enclosures.

 

[MKR]

Iconic marketer in the '70s and '80s. Here's a sample.

So you are inferring the GSG Devastator is all marketing and no substance? Or just making fun of the name?

 

[voodooless]

I do think that in many applications good "pro drivers" (vs inefficient dedicated sub drivers) with "as much LF extension" and "more" mid-bass output makes for a better solution.

Sure, I already eluded at those in my earlier post, but that kind of a setup isn’t a typical home audio subwoofer setup where the crossover is at 80 Hz or lower.

In conclusion , I would say: if your box is small(ish) and closed, get the Ultimax with lots of amp power. If you have plenty of room: go with the LaVoce ( and in that budget range, other PA woofers are also available), ported, tuning low, add some EQ. And if you want the most out of it, put them next to the mains crossed over higher than normal.

 

[stevef22]

I just finished building 2 GSG 18" "Full Monty" subs with the LaVoce drivers.

A few thoughts.

GSG kits are great. Very well braced, precision cut, good instructions.

I am running my "Full Marty's" sealed and prefer them that way for music. If I was going to do it over again I would start out with large sealed and well braced enclosures with a Qtc 0.707. Old school and "too big" according to some but easy, reliable, and great time domain performance which is the downfall of many "modern" subs.... DSP makes advertised specs look good at the expense of group delay / transient response.

LaVoce drivers are great, much higher mid-bass output which can be "shaved off" if needed. Due to lower X-max and higher efficiency they have less distortion but still plenty of LF extension in the right enclosure, probably more than the Daytons at reasonable distortion levels. You may find that big subs not only fill in the LF but they also can put out high SPL ~100 Hz which is where the majority of the energy in most music lies and many main speakers start to distort or compress more than you might think if you are trying to play loud. For dedicated sealed subs there are probably better drivers but I would stick with the "pro-audio" drivers.

Not sure what you are planning for amplification but there is someone on ebay selling brand new Crown XLC21300 (1,300 watt per channel 4 ohms no DSP) very cheap. I was worried but bought one and it really is brand new in the box and is prefect for this application. Since it is a Professional Cinema amp the hook up is not standard but it is not hard. https://www.ebay.com/itm/364056130409?_skw=crown+XLC21300&itmmeta=01JZR76WY7VV23PS8N0TJWA3FG&hash=item54c36fb369:g:SFAAAOSw2g9jBnxP&itmprp=enc:AQAKAAAA8FkggFvd1GGDu0w3yXCmi1eZNESBJrU2qSfHodm7lZJmecXZSfxEzqgL+yFX7tx9dvnGCxoEX/k7CPofxtqQsbmPVjXuPHWLAwJiZYpABPhwsp7QuTgw47jFwvy6+thZohDoG7i+1NubTIgpLz2OSMSXaCu7N9WvW5rI5l4C1TsSEBeLUF28QdKKJpYe4BVO+nItFiigi3Qk5gHm9SeP0kl36a8+L7heC9D+yw6GvfPL198s3M+IFr/WmG/PQMoDBrbR4B8mDZoUK2KeeRLOXCK8zwR8IjZFQYyO1/5/OicEIkXjxcavKf8BIcbe6Fasqw==|tkp:Bk9SR5bPm4f-ZQ

Good luck and have fun

Thanks for the tips. I asked GPT to make me a box with similar QTC. Here is what it came up with for the Lavoce speaker

GPT​

This 25"×24"×12" sealed box will make your electronic music come ALIVE. The 0.70 Qtc gives you that perfect balance of control and impact that makes EDM and Drum & Bass absolutely addictive to listen to. Your Lavoce driver will hit harder and sound more exciting than in any larger box.


Also I just got a Crown CTS 2000. Amp. 1000w amp. I think this is good.


Thank you for all the advice and tips.

 

[stevef22]

Why did you decide that? Personally, I wouldn't make that decision without modeling with software first. Some speakers work better in sealed cabinets and some better in ported cabinets. And if you have size constraints (which I think you don't) the size of the box can also influence whether a ported or sealed cabinet performs better.


Again, you don't normally "tune" the speaker for the room. You build (or buy) the best speaker you can and then you can optionally use EQ and/or acoustic treatment to deal with acoustic problems. ("Regular" acoustic panels don't help with bass. You need bass traps or other methods to fix bass problems.)

"Leaky" is usually good! The problem is usually with reflected bass and holes in the room are very effective "bass traps". Minimizing the reflections reduces standing waves, smoothing both the dips and the bumps. The bumps (where the direct and reflected waves add together) can usually be knocked-down with EQ but the dips (where the direct and reflected soundwaves subtract & cancel) can't really be fixed with EQ because it takes "infinite power" to overcome cancelation.

Bigger rooms also tend to be better.


The main thing is generally the internal cabinet volume, not the shape. With a ported design, cabinet volume, port volume, and port length/volume interact to affect the tuning.


You can enter the parameters into WinISD just as easily as me, and I'm lazy! Plus, if you do it yourself you can try some changes (virtually), including comparing sealed & ported, to see what happens.

I decided that because I want to build my own first sub... And Im not skilled enough with the math/WINISD to make a ported version.

I will be checking out WINISD for sure though. Its just allot for a novice to take in. When I get to PC (currently on MAC) I will be checking out.

On GPT I asked for a ported box here https://claude.ai/public/artifacts/dc9f1bc0-33c6-49c3-af62-e9becf193dbb
Does it make sense?

Thank you very much for all the advice and tips. Im happy to have a leaky room. : )

 

[OldHvyMec]

Wow, ok so now I’m really confused. But still learning

Can you help model me a cabinet for the

LaVoce SAF184.03 18" Professional Subwoofer

I've never used the driver.

I can't comment on how it would work.

I pretty much stuck to Dayton, Eminence, and JBL for pro drivers. HIFI subs weren't a thing until the late 70s and then really popular by the early 80s. VMPS, and Infinity drivers were available at a reasonable price for sub builders at the time. VMPS had a deal going with PE and Infinity at the time. He later started building his own 10, 12, 15" drivers from "shark skin" (WCF). I use a few of his drivers. I think he used Misco also for smaller subs, MB couplers, and some woofers.

Currently, one of my favorites before the price jumped so much was Dayton's HO series, and the HO44-10 was the best I've ever used in sub/bass columns. 6, HO44-10s and 2 15" RS passive in a 12 or 16cf column. 15hz-250hz. They worked great for any large panel planars and were extremely fast drivers to return to center or control overshoot when directly coupled. A passive DCX2496/NU12,000 or even a Dayton 1000-watt plate, you'd better tape single-pane windows. I built 10-12 pairs, but I sold a few trips and singles.

They outperformed all of Infinity's IB and were a LOT louder and with less distortion than even their servo IRS 10/12". I was a Servo fan from the late 80s to the present.

I use GRs 12" servo drivers, Rythmik plates, and DIY OB cabinets in one of my systems with SAT Bass columns I used to build. I've NEVER heard better, that I can afford.
It's been a while since I was able to handle the plywood/MDF (3-4 years) to tell the truth.

I think I have some pics. The 8" drivers pictured here are Dayton RS series. 6.5, 8 or 10" and in 3, 6, or 9 or 2, 4, 6, 8 SAT driver cabinets. Stack and Test.
I built at least 20-25 set of 3/6 driver columns. I'd have to look in the build book.

BTW, some people like to model their subs, and then guys like me muddle their builds. LOL I've never had a single complaint, though, other than the stupid $hit dropping the cabinet off the back of their van and snapping a Queen Ann leg off.

Regards

 

[stevef22]

I've never used the driver.

I can't comment on how it would work.

I pretty much stuck to Dayton, Eminence, and JBL for pro drivers. HIFI subs weren't a thing until the late 70s and then really popular by the early 80s. VMPS, and Infinity drivers were available at a reasonable price for sub builders at the time. VMPS had a deal going with PE and Infinity at the time. He later started building his own 10, 12, 15" drivers from "shark skin" (WCF). I use a few of his drivers. I think he used Misco also for smaller subs, MB couplers, and some woofers.

Currently, one of my favorites before the price jumped so much was Dayton's HO series, and the HO44-10 was the best I've ever used in sub/bass columns. 6, HO44-10s and 2 15" RS passive in a 12 or 16cf column. 15hz-250hz. They worked great for any large panel planars and were extremely fast drivers to return to center or control overshoot when directly coupled. A passive DCX2496/NU12,000 or even a Dayton 1000-watt plate, you'd better tape single-pane windows. I built 10-12 pairs, but I sold a few trips and singles.

They outperformed all of Infinity's IB and were a LOT louder and with less distortion than even their servo IRS 10/12". I was a Servo fan from the late 80s to the present.

I use GRs 12" servo drivers, Rythmik plates, and DIY OB cabinets in one of my systems with SAT Bass columns I used to build. I've NEVER heard better, that I can afford.
It's been a while since I was able to handle the plywood/MDF (3-4 years) to tell the truth.

I think I have some pics. The 8" drivers pictured here are Dayton RS series. 6.5, 8 or 10" and in 3, 6, or 9 or 2, 4, 6, 8 SAT driver cabinets. Stack and Test.
I built at least 20-25 set of 3/6 driver columns. I'd have to look in the build book.

BTW, some people like to model their subs, and then guys like me muddle their builds. LOL I've never had a single complaint, though, other than the stupid $hit dropping the cabinet off the back of their van and snapping a Queen Ann leg off.

Regards

Thank you for all the info

 

[Pieter1267]

I just went from ultimax to b&c 21ds115. Dayton Ultimax is not for mid bass chest punch. They are good, love a lot of dsp but you want 40-60hz perfomance choose the Lavoce or a different Dayton.