Dayton Audio 21" Pro driver - Page 2 - AVS Forum | Home Theater Discussions And Reviews
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post #31 of 65 Old 06-02-2020, 08:25 AM
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Very similar to the PA460 in response shape, just louder. Definitely a candidate for a 21" version of the VBSS.
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post #32 of 65 Old 06-02-2020, 08:51 AM
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At three times the cost of the PA460 though. I wonder how a single 21" VBSS would compare to a pair of 18" VBSS's?
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post #33 of 65 Old 06-02-2020, 08:56 AM
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Quote:
Originally Posted by Samps View Post
12 cubic feet ported 20hz, 1000 watts, 14mm xmax, 20hz hpf ---vs--- 4 cubic feet sealed, 1000 watts, 14mm xmax

Why 14mm?

xmax is 11mm, and it's for real, based on 70% BL, so [VC height - gap depth]/2 is likely even less.

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post #34 of 65 Old 06-02-2020, 09:01 AM
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A pair of VBSS with the 460 will beat the 21 on the top end and be about the same on the bottom. So a pair of VBSS is better, but you will need a little more total box volume. Pretty much the case for any driver. In almost every case a pair of smaller drivers will beat the single larger driver.
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post #35 of 65 Old 06-02-2020, 09:05 AM
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Quote:
Originally Posted by noah katz View Post
Why 14mm?

xmax is 11mm, and it's for real, based on 70% BL, so [VC height - gap depth]/2 is likely even less.

We have seen pretty much every Dayton driver tested to have a few more mm xmax than the spec. That is why I stated the xmax I used in case it was not possible, but we won't know until someone tests it. I would imagine the PA460 is listed with an xmax spec'd on the same criteria, along with most of the other Dayton drivers, and they all have a little more xmax. Who knows, maybe they spec'd this one a different way.
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post #36 of 65 Old 06-02-2020, 09:07 AM
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Quote:
Originally Posted by Samps View Post
A pair of VBSS with the 460 will beat the 21 on the top end and be about the same on the bottom. So a pair of VBSS is better, but you will need a little more total box volume. Pretty much the case for any driver. In almost every case a pair of smaller drivers will beat the single larger driver.

So VBSS's with the PA460 are still the king of the hill budget wise. I'm building my first (a dual driver VBSS) and plan to add another once the PA460 goes on a major sale again (hopefully $75 like BF). I've even got space for two more if for some reason 4- 18" drivers aren't enough!
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post #37 of 65 Old 06-02-2020, 11:26 AM
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The product description says "11 mm of excursion in each direction (@ 70% BL, Klippel verified)."

I guess "verified" potentially means meets or exceeds, but if it did exceed it I expect they'd increase the spec to increase its market appeal.


Quote:
Originally Posted by Samps View Post
We have seen pretty much every Dayton driver tested to have a few more mm xmax than the spec. That is why I stated the xmax I used in case it was not possible, but we won't know until someone tests it. I would imagine the PA460 is listed with an xmax spec'd on the same criteria, along with most of the other Dayton drivers, and they all have a little more xmax. Who knows, maybe they spec'd this one a different way.

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post #38 of 65 Old 06-02-2020, 12:55 PM
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Dayton has proved that in the past they've gone for safer numbers.

I wouldn't expect the behavior with every driver tough. As long as 14mm doesn't hit xmech than 3mm more excursion won't hurt simulations as long as you anticipate a rise in distortion for the expected FR where it throw is too long. I also don't think this driver was created as a successor to the PA460, looking at it price wise, this looks like a really solid attempt at a cheap, tour grade 21".

but really, I'd like to see this in either a TH or FLH tuned to around 25hz.
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post #39 of 65 Old 06-07-2020, 09:44 PM
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Ok, two questions:


1. How does one of these model if it's dropped into the traditional 6.25cu/ft VBSS cabinet? I know Samps modeled it at 12cu/ft, but hypothetically, if someone already has a couple VBSS cabinets and just wanted to modify the baffle to be 21" ?


2. Has anyone looked to see how these will perform in the different Devastator designs?
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post #40 of 65 Old 06-08-2020, 09:38 AM
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Bottom white is pa460 in 6.5 20hz
Top white is 2x pa460 in 13 20hz
Red is 21 in 6.5 20hz
Yellow is 21 in 12 20hz

460 is modeled using 9mm xmax, 21 using stock 11mm xmax. I used the max spl tab since this is to demonstrate the VBSS which uses DSP to manipulate the response, so max spl seemed most useful here.



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post #41 of 65 Old 06-08-2020, 09:42 AM
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Should be noted that using the 21 in the VBSS box would require larger ports to accommodate the higher displacement, which would in turn lower the total box volume. My models did not account for that.
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post #42 of 65 Old 06-08-2020, 11:55 AM
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It looks like two PA460's are hard to beat, especially since they would be 1/3 cheaper than the 21".
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post #43 of 65 Old 06-08-2020, 12:25 PM
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A pair of 460s does look good against the single 21, but I don't think it would be cheaper. You will need twice as much wood, lining material, wiring/terminal, duratex/paint. All that stuff adds up to probably $100. But two will have the benefit of smoothing the response. Two obviously take up twice as much room. I'd say they are both good options for different needs.
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post #44 of 65 Old 06-08-2020, 12:30 PM
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Well, a dual 18" 13cu/ft box wouldnt be much different from a single 21" 12cu/ft box, material wise.
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post #45 of 65 Old 06-08-2020, 01:09 PM
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Quote:
Originally Posted by eXa View Post
Well, a dual 18" 13cu/ft box wouldnt be much different from a single 21" 12cu/ft box, material wise.

I was thinking two $100 drivers rather than a single $300 driver. I agree the rest of the box wouldn't be much different.

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post #46 of 65 Old 06-08-2020, 01:11 PM
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post #47 of 65 Old 06-08-2020, 01:14 PM
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Quote:
Originally Posted by Mocs123 View Post
It looks like two PA460's are hard to beat, especially since they would be 1/3 cheaper than the 21".
My thoughts exactly at the beginning of this topic...

The 21" driver is just too expensive vs two 18" drivers.

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post #48 of 65 Old 06-08-2020, 02:03 PM
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Sorry, I thought you were comparing one 21 in a VBSS vs two 460s in two VBSS. That would require twice as much stuff for the 460s.
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post #49 of 65 Old 06-14-2020, 01:25 PM
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Thanks for doing the additional modeling, Samps.


I had no idea how much better the PA460s look in 13cu/ft compared to the VBSS cabinet!
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post #50 of 65 Old 06-14-2020, 07:33 PM
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Quote:
Originally Posted by Craig S King View Post
Thanks for doing the additional modeling, Samps.


I had no idea how much better the PA460s look in 13cu/ft compared to the VBSS cabinet!
It's a 6dB gain going from one to two VBSS, that's all you are seeing there. No change in enclosure, just two of them.
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post #51 of 65 Old 06-14-2020, 09:46 PM
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Oh, ok. I thought I was going to have to sell all of my VBSS cabinets and start building new 13cu/ft cabinets!


Now I wonder what two 21" drivers would look like with the 12cu/ft and 20hz tune Samps was using....
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post #52 of 65 Old 06-18-2020, 11:47 AM
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Suuuuuuuuuuuper intrigued by this new 21" option! (FYI Alice needs to stop eating those pills, this whole big, small, big, small cycle is making me dizzy!)

Apologies for my usual long-winded posts, lol.

So, I had devised a plan, but given the introduction of this new driver at a fairly wicked price point, now I am second guessing and possibly changing said plan.

Anyway, the original plan started like this:

My ULF monster sub (dual opposed AA Avalanche 15s tuned to ~11Hz) is grrrrrrrrrreat for insane SPL from 10Hz up to 50Hz. I get about a 10dB drop from 50Hz to 60Hz, and it remains fairly flat from there up to 100Hz. I EQ'd the 60 to 100Hz area up a bit, and it is better but needs some help still.

I am also running a lilmike's Cinema F20. By itself, it does great in the midbass. However, due to lack of optimal placement options, I ended up with the mouth of the horn firing sideways in the only place it will fit in the living room. It used to be in the corner where the ULF box sits now, with the mouth firing almost directly at the couch.The ULF box only fits in that corner, so that is where it is going to stay. The combination of non-ideal placement of the horn, plus mixing it with ported boxes, wreaks havoc on the frequency response. I have measured and tuned and still feel it is lacking chest slam. I might be able to get it a bit better than it is, but I have this thing called an addiction. In order to satiate this addiction, I must build more boxes!

I picked up a blown Aurasound 1808 from the 'bay for wicked cheap. I contacted PSI (www.fixmyspeaker.com) about having them set me up with something similar to the TC Sounds A1808 basket that was once available. I also might be purchasing 2 more 1808 motors, depending on PSIs response to my inquiry. See, the TC A1808 assembly required the removal of the 1808 motor's Faraday ring. Their reasoning was that the increase in Le was inconsequential, and the Faraday ring decreased the gap clearance too much for their coil. Now, I must stress that I would like to keep the Faraday ring. Of the two motors I am looking at purchasing, one has had the Faraday ring removed. The seller wants to sell both motors together, which I understand. If PSI feels the same as TC and doesn't think the motors are usable with the Faraday ring, then I'll purchase both motors. If they feel they can make the Faraday ring work, I'll keep looking for 1808 motors that have not been modified. PSI is crazy backed up at this point, so I have not heard from them yet.

The plan was to build a large ported box for 2 Aura Hybrids that will fit where the F20 currently sits. I think replacing the F20 with another ported box will make it much easier to get all the woofer boxes playing nicely together. The 1808 hybrids would decimate the midbass, and given the large Xmax and linear BL curve of the underhung neo radial motor, should have no issues pushing the lower frequencies as well.

But, given this new 21" option I am at an impasse. For 300 bones each, it is quite a bit less expensive than going the Aura route. If I choose the 21" path, I'll continue to look for Aura motors, hopefully at a price point similar to the blown driver I got from eBay, and save them for the basement towers and center channel. If I can find enough of them, they would be amazing for what I have planned for the basement.

Time to run some sims... what say you? WHAT SAY YOU?!!!


EDIT: I happened to have taken a photo of my measured ULF sub in room response, and I actually only lose about 10dB between 50-60Hz, not 20dB as originally stated.

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post #53 of 65 Old 06-18-2020, 03:42 PM
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Initial model impressions for my usage.

(2) 21" drivers. Big box - 18 cubic feet net, probably 20 cubic feet gross. Low tune - 11Hz (to match my other subwoofer). Large-ish port - 6" diameter, 30.45" long.

4th order Butterworth (gives a little more low end vs LR) High Pass at 10Hz - 900W input (my amplifier's rated output at 4 Ohm)

Never exceeds Xmax (11mm) - 102dB @ 10Hz, steady rise to 120dB @30Hz , steady rise to 128dB @100Hz

Port velocity even with a 6" port is very well behaved, mainly due to the low excursion. A 6" port means I could buy a Precision Port.

Really liking this driver. I'm sure other 21s would model similarly, but the next closest 21" driver in price is the Lavoce SAN214 at $450.

For reference, the (2) 18" PA460s are modeled in the same box, but only given 350W to keep excursion under 9mm. If the PA460s had 14mm Xmax they would handle the full 900W and model dang near identical to the (2) 21s. Interesting!

Just a note - I did have a 4th order LR filter at 10Hz on the PA460s. With a 4th order Butterworth like the 21s, they do not exceed 9mm on the low end, and the curve looks identical to the 21s just with lower output due to lower power input required to stay under 9mm excursion.


Edit: As an aside: I model everything with inductance simulated. I know it isn't really accurate, but the roll off on the top end seems more appropriate than a flat line to infinity.
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post #54 of 65 Old 06-19-2020, 04:18 PM
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I'm yer huckleberry!


(2) 21" monstrosities on their way... (yes, I know I have a problem, but I choose to ignore it, lol)
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post #55 of 65 Old 06-24-2020, 12:38 PM
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Who's excited? This guy!


My 21s should be here tomorrow! I'll take pics and post 'em up along with my impression on build quality. It's Dayton, so should be nice quality, though they have had a few hiccups here and there in the past.


Gonna hook them up in parallel to my QSC PLX3002 and do a little free air testing as well to make sure they are good to go!


Almost done with my box design. Currently it sits at 18 cubic feet gross. I'm waiting to see how PE responds to my question regarding the box volume displacement of the drivers before I finalize things. I'm hoping to get away with about 16 cubic feet net after driver, bracing, and port reduction. It doesn't model quite as well as a 20 cubic foot box (18 net), but I'm angling the woofers (like a corner box) to fire at the listening position and avoid firing directly at the person sitting right next to them on the love seat. Knocking off the corner reduced the volume about 2 cubic feet. We rarely have anyone sitting in that spot on the love seat, but even with the woofers angled they'd still probably go deaf, haha.


A little preview (top down view)
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post #56 of 65 Old 06-24-2020, 03:20 PM
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Looking forward to hearing your impressions!
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post #57 of 65 Old 06-24-2020, 04:15 PM
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Someone else said something similar but I would love to see a Flex 21 (VBSS) version of this. Maybe around MiniMarty size with variable tuning for music or movies? Although wouldn't really be a Value Buster since you would probably need the NX6000DSP, 6" ports and more wood. Value in terms of a 21" though....
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post #58 of 65 Old 06-24-2020, 09:36 PM
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Quote:
Originally Posted by Zarkoff500 View Post
Someone else said something similar but I would love to see a Flex 21 (VBSS) version of this. Maybe around MiniMarty size with variable tuning for music or movies? Although wouldn't really be a Value Buster since you would probably need the NX6000DSP, 6" ports and more wood. Value in terms of a 21" though....
Interestingly enough, it does pretty good with smallish ports. Partly due to the 96.3dB sensitivity combined with the the large cone area, but it doesn't need much excursion for high SPL. Even for the dual driver box I am planning, a 6 inch port is fine for an 11Hz tune without pushing port velocity into chuffing territory. I asked PE what the Xmech is, but considering the PA460 has been known to double it's rated Xmax without bottoming I would think 19-20mm wouldn't be out of the realm of possibility. If I were to feed 2000W into the box I am building, the excursion is a little over 14mm each, and with a 6 inch port the velocity ends up around 28m/s, which should be fine. I only have about 900W to give it currently, which doesn't exceed the rated Xmax with a 4th order BW filter at 10hz. Even without the high pass it doesn't exceed 11mm until about 8Hz. If I played around with the high pass I could get away with boosting the low teens quite a bit without running into excursion or power issues with only 900W.

With my dual 15 AA Avalanche box I had to use an 8" port minimum to keep port velocity decent, but 27mm of Xmax and using every bit of it moves a lot of air through the port.
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post #59 of 65 Old 06-26-2020, 12:51 PM
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Alright, I know you've all been waiting with bated breath for an update, lol.

Received the two woofers yesterday. Here are my impressions:

Packaging - 9.8 out of 10

Arrived double boxed in heavy duty boxes. Driver was in a plastic bag containing a silica moisture packet to keep it dry. Two super thick (3-4" thick) square cardboard inserts with countersunk cutouts that fit the motor and the rim of the driver. The rim was a tight fit to the one cardboard insert, and there was approximately 3/8" thickness covering the face of the driver to further protect the cone. Tight enough fit I was able to lift the driver out of the box using the cardboard. I made sure I had fingers under the rim just in case the cardboard started to slip off the driver. I've no doubt the driver was well protected. Two plastic fiber bands around the box (shipping straps) to aid in lifting.

The only thing that would have been nice would be cutouts in the sides to help lifting after removal of the plastic banding, but I get that they did not want to sacrifice box integrity. The bands worked perfect for getting them in the house. Great packaging overall.




Product - Build Quality - 9.5 out of 10

Quality materials throughout. The magnets were pristine, no chips or oddities. Aluminum top plate a machined thing of beauty. Nice bumped back plate. I was surprised at the diameter of the 6 vent holes in the back plate. You can tell they put a lot of work into designing the airflow through the motor for cooling.

While inspecting the first woofer, I was somewhat concerned about the spider. There is a layer of glue spatter on the outer face of the spider. It is consistent all around. I unboxed the second woofer and it has the same conditions. I was concerned that this may have been the result of extreme shipping temps - that the glue should have been impregnated into the spider, but super hot shipping temps might have caused it to bubble out. I was confused because the temps seen during shipping should not be more extreme than the conditions seen inside a box after hammering the woofers for hours on end. These are Pro woofers after all. So I reviewed the photos on the PE webpage, and they show the same thing, so I assume this is a design decision.

My thoughts as to why the glue is applied: If you look at the PE photos of the inside of the motor, the cooling vents that are in the back plate extend through to the area under the spider, so the spider provides pumping action to push the air through the motor. The glue is pretty rubbery, so I doubt it increases the stiffness of the spider much. What it does do though is make the spider a little less porous, which increases the amount of air pushed through the motor. Just a guess, but makes sense.

So why the 9.5 rating? Well, the frame is definitely plenty stiff enough, but could be a little beefier in my opinion. It is not any thinner than the frame I have for the Aura 1808, so I doubt it will have any issues. Also, the glue that holds the spider to the frame has a couple spots around the perimeter that could have been a little wider. The spider is adhered very well, so this is really just an observation.


Product - Value - 10 out of 10

What can I say about a 21" woofer that has this build quality and only costs $300 (actually less since I used the coupon code for $50 off $500)? It may not have the highest Xmax, but there are pro woofers costing much more that have lower Xmax ratings. If you were reading a description on USSpeaker it would state: High Xmax of 11mm, haha.


Product - Initial Free-Air Testing (Observation Only)

I hooked them up in parallel to one channel of the QSC PLX3002. Checked with the multimeter it was right around 3.0 Ohms. My multimeter is a cheapo so I really just use it to confirm I have them hooked up properly. Started with some Wreck It Ralph since it isn't known for heavy bass and I didn't want to overdo it in free-air. Got 'em moving decently in a couple scenes. Progressed through a couple more movies with increasing bass content, and ended with the Transformers final battle scene. I figured the significant other would rather watch things than listen to sine waves. Transformers got them moving quite a bit. I didn't push the volume, and I still had the 18Hz high pass filter in the MiniDSP on that channel, but no other EQ.

No odd sounds, no swooshing motor sounds, smooth excursion, even when pushed fairly hard - Bumblebee destroys Brawl (I drive, you shoot) sweep had impressive excursion. I had them supported at an angle so the motor vets could do their thing without hindrance.

Most likely on Sunday when my girlfriend is at work I will pump some sine waves through them for a little bit to see if I can loosen them up a bit. I need to get my DATS back from my dad to measure T/S parameters. Maybe I'll swing by their place after work and pick it up. I'm not sure if he is done using it, but I can always return it later. No big thang.

Anyway, on to the photos!
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drewp29 is offline  
post #60 of 65 Old 06-26-2020, 07:08 PM
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The glue joint doesn’t look too bad seeing as it’s a $300 21” but still i would expect better.


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