Ricci

I have been in that scenario plenty of times. The room is small and usually full of hard reflective surfaces and the drums are titanic loud, which of course causes the bass and guitars to compensate louder and you end up with a scenario where the pair of 15" 2 ways that are usually in such a place can't get the vocals up over top of it. I'm not saying this doesn't happen and that it's easy to attempt to work around...Hell sometimes the drummer has a very light touch and gets completely drowned out by the guitar player who has to have a full stack running at 10 even in a 50 person room. Seen that one way too many times. A lot of this depends on the music style too. If you are a Folk-rock group with quiet female main vocals and 3 part harmonies the drummer shouldn't be hitting through the heads the whole time. Play should be appropriate to the music clearly. That's the thing though if you are playing "heavy" aggressive music like east coast hardcore or something the drums are supposed to be hit aggressively. The double whammy with heavier bands is often the scream or growl type vocalists don't really have much projection or power. That's not always the case but it is a lot of the time. You end up with a very loud band and a vocal mic that needs a LOT of gain = feedback and tons of stage bleed. Back to the too loud drummer issue...My point is not about being able to play with less force. You should be able to play the same phrases or beats at a variety of volume levels without issue. That's 101 level stuff. Being able to do that with a beat or drum phrase does not mean that they will all offer the same sound, feel, dynamics or emotion to the drummer, the band or the crowd. As an example. Imagine...You are drumming in that east coast hard-core band...the big break-down comes... The whole crowd knows it from your first album...The ninjas are about to kungfu up the dance floor and!...You kick in at about 50% volume of normal because your drums are going to be too loud. Try to act like you are going hard, but you know you're not it's just an act. That situation is one I've been in and it sucks. None of the other instruments have to deal with that type of thing. That's all I'm saying really. Stupid loud ass drums and cymbals! Deathcore band eh? Blasts and skank beats? Triggers?

I often hear sound guys talk of too much stage volume from the band members especially drummers, but it's not as simple as just play quieter like it would seem to be. It can fundamentally affect the entire feel of the composition for the drummer, the entire band and even the audience since the group now has less energy, especially in the smaller intimate venues where this type of problem usually occurs. Basically you are asking the drummer to tone it down, and not put nearly as much energy and dynamics into the performance as usual. Usually there's a reason these drummers play like this. I'm one BTW...Usually drummers that are really loud are used to playing with little to no PA reinforcement (perhaps just kick if even that) and having to provide the beat with acoustic drums only while competing against amplified instruments. If you think about it there is probably no other instrument that you would literally ask the person to alter their usual playing style and performance in such a big way. I guess you could go to an all electric kit with triggers but that carries a host of other trade offs. In the smaller clubs or bars with live musicians the "PA" often isn't really needed a whole lot for overall volume, but mostly for vocals, samples and other instruments which need a boost in volume. In large clubs and especially arenas there is often enough distance and dispersion to work around loud players and the PA does a whole lot more work in these situations. Anyway that's a subject I'm very familiar with.

STILL for sale...I'm losing my ass on all of these at these prices. Qty (2) 18 Sound 21NLW9601 8 ohm drivers. $800 takes both shipped and insured. $700 local pickup. Will separate... Qty (1) 18 Sound 21ID. $430 shipped and insured. $390 local. Qty (1) MTX 9515-44. $430 shipped and insured. $365 local.

It'll be an Alpine Type R 15", an MTX 9515-22, a Peerless STW-350 and 2 MTX 9515-44's. I'm not ready to sell any quite yet though. Still have to test em. Edit: I can sell one of the MTX 9515-44's. See price below.

You can completely ignore the winisd recommendations. In fact you should also ignore qtc for the most part. IMHO. I never use it for design work anymore. Start with a size that is practical to build such as a 17" or 18" cube and use that calculated volume for modeling. Use the model to determine an appropriate amount of power to use. Don't worry if the excursion below 20Hz seems to go beyond Xmax at low power. It will due to a very low qtc alignment. The DS series drivers are almost impossible to bottom out and it takes WAY more power than winisd will show to push the driver beyond 20mm excursion. The driver does not respond linearly to power increases beyond Xmax and a little past 20mm one way even huge increases in power will not push it further. It is effectively done at 25mm no matter how much power is dumped in.

They have the same amount of total displacement effectively. The 21Ipal is a little more efficient.

It's 5 Listed as "Measured Complex Inductance Parameters" under the individual "Drivers" page.

I'll reply a bit more later but let me say that when modeling for maximum output, otherwise known as "Bench Racing", there are a number of limitations about simulations that should be kept in mind. 1.) Sims are usually greatly simplified and usually lack a variety of effects that occur in the real world like non linearity in the drivers BL, suspension, thermal effects in the voice coil, port and other air flow related losses, etc. All of these cause compression of the output. 2.) Sims are only as good as the data input. 3.) Amplifiers are not constant power devices, they are constant voltage. Speaker impedance varies with frequency. 4.) System output is usually limited by a number of different factors. Driver excursion, amplifier voltage, amplifier current and the resulting amplifier power are the main limitations. Which limitation kicks in first depends on the frequency range. There are also other factors such as vent compression, PR excursion limitations and thermal compression or power handling of the driver to consider. Horn Response allows a good approximation of max output based on entry of a number of these parameters. This is what Peniku was showing in his simulations. Limiting by wattage isn't really the best way to go about it. 5.) Power handling and xmax ratings are not all created equal. 6.) Eq can modify the driver excursion profile and which frequencies run the amplifier or driver into the limits first.

That sounds about right. Might be useful for HT if you find you aren't using all of the headroom a pair will provide.

I'm assuming sales were slow at the prices these went for. I haven't seen anyone else on the forums post about having an SHS-24. I figured a few would've been bought during the closeout sale. I always get at least a pair of drivers.

Excellent...I may have to buy one of these units for my tool kit.

Ahhhh. I think you're right. Unfortunately according to the SI website that may be the case for these drivers, which is a shame. I wonder how many were sold at the sale price last holiday season. Perhaps it'll be a small batch as requested type of deal. I need to get my ass in gear and figure out what type of cabs I'm going to build to test these. I still have the giant sealed cab from the original HS-24 testing. I'm tempted to see if I can somehow cram 2 or 3, 6" aero-ports in that cab without too much trouble.

What John is describing is very similar to how I do it. One difference is I run the sine wave looped back through the RTA and monitor the THD. It should be well below 1%. Once it starts to clip you'll see the harmonic content jump abruptly and THD shoot up over 1%. It usually happens very abruptly. If the device has a clipping indicator you may find this happens well before or well after the indicators. You do have to make sure that this is the output voltage clipping and not the input though. To reiterate a voltage divider will probably be required. I cheat and use one of my DCX2496's in the chain usually. They will take an input of >10 volts before clipping and can easily reduce the signal to something that your SC input can handle when looped back. Go through the components one piece at a time starting with the AVR, then adding the EQ unit and finally the amplifier. You want to eventually get the highest voltage cleanest signal that you can to your amplifier and then set the amplifier so that it is the first thing that clips. This also helps keep your electronic noise floor as low as possible. Definitely disconnect all speakers. They aren't needed for any of this testing.

Interesting. Are you planning to do any testing of this setup? What is "the device"?

It's best to start out by defining some things. DIY can definitely offer some advantages and cost savings but the tradeoff is a higher amount of sweat equity and possible increased difficulty in integration and setup. Like More mentioned some of your goals are at odds with each other. What is your budget? What size can you subwoofers be? Define some hard limits on the dimensions. How loud do you plan to listen? Are you wanting front row concert or EDM show levels or just good clean low end at moderate levels? The best bang for the buck amplifiers are external rack mount pro amps. Plate amps cost more and must be accounted for in the enclosure design and build. Your post makes it seem like you would like the amp to be placed with the subwoofer where you have a pre-existing RCA cable. I recommend using XLR balanced cables where possible especially if going DIY. long runs of RCA unbalanced can have issues with noise.

What does NLA mean?

Don't worry about it. It's kind of on topic anyway. Personally I am not a fan of MDF. I don't like working with it and it doesn't hold screws well. Also it hates moisture. I'd rather use a cheap Arauco ply or similar if the 13ply void free stuff is too expensive. I've done a number of cabs out of cheaper ply materials and they've turned out fine.

Looks good man. Are you building a pair of these or just 1? You forgot to post tuning with one of those ports stuffed.

These don't look right to me. The response shape looks off. Are you using the generic LE (red Le) function?

It's not stuffing. It knocks down high frequency radiation from bouncing around inside of the cab. You may think low passed subwoofer = no high frequency radiation but that's not entirely true. Distortion, mechanical operational noises, internal standing waves in some cases, air noise, leads vibrating against cab walls, etc...Anyway I've always lined my vented subs because it does knock down these junk noises a bit. Try snapping your fingers or knocking on the side of the cab with no lining and then with some lining, with your head inside.

+1

Sensitivity will measure low on a dual opposed cab when measured from 1 location. I've got an article on this subject on the main website. Can you post your model inputs and the physical characteristics of the cabinet?

I'm not surprised. It's probably used as a tactic to sell Atmos & get higher penetration into the market by how much obviously "better" it sounds. Or perhaps they have 2 different mixing teams working on the tracks separately? Resulting in 2 different mixes? That seems like a monumental waste of time and money though. For coherency and efficiency you'd want to change as little of the mix as possible between formats. One would think at least.