Ricci

Yep...Definitely helps get what you can from a junk AC supply

4 of these and a pair of PM90's should be quite a good sounding setup and compact for the performance available. I've not personally heard the PM90's but I've looked at the design and talked with guys who have built and heard them. The feedback and measurements are positive. Amplification will depend on budget, channel needs and available mains supply. You've got everything from Behringer at the cheap end on up through something like a PS X8. Would the PM90,s be active?

Cool! Looks like a good time. Where are you located? That's a nice looking chunk of land. The Keystones are bigger than I thought. What drivers do you have in them? What drivers in the Skram's?

Haha! Excellent work. I'm glad you like them. If you don't do CF/poplar/epoxy logo/acrylic front, they won't match! 😆

A LOT of variation is allowed even from the best manufacturer's. SVS undoubtedly has a ton of internal documentation on the drivers. They could've sent the data to a reviewer or someone else. Word gets around. Those are the specs from the OEM?

Nice link back to your website...Exactly where did these parameters for the drivers come from? Just a repost of factory SVS specs? You should be aware that the specs and Klippel results posted earlier in this thread are from a guy who knows what he is doing and has access to some of the best testing equipment available. Also driver specs that vary by up to 30% or more are considered in spec in most cases. This is very common in the industry. No two units will ever test exactly the same. The specs posted by ITR earlier are not that far off from the specs listed for the PB16U driver. Well within industry tolerance for drivers.

Looks great to me. Take your time and don't worry about small details. It'll be fine. When in doubt PL premium will fill any gaps!

I'm selling off the HF section of my BIG 2ch music system. 1 pair of JBL 2360A 90Hx60V horns with brackets and throats. 1 pair of JBL 2245H 8ohm compression drivers. Condition of all is used. Expect scratches, a LOT of dust, dings etc...These are old units and aren't much for looks but they perform. The 2445's have the original JBL diaphragms to my knowledge. I believe the drivers might be original to the horns FWIW. The red terminal is loose on both CD's but they've always been that way and work fine. I've been using them for a very long time and have recently bench tested both drivers to make sure that both are good to go. I'd like to keep everything together if possible. $700 takes it all... Due to the gargantuan size of the horns I am not shipping these. Local pickup in the Louisville KY area. I'm willing to drive a few hrs to meet someone halfway for an extra $50 in gas money too.

For the price these look pretty decent. The other option in that price range are the Type S 12 which has a lot lower motor force. Really the only thing the UM has going for it over this is the shorting rings and possibly lower distortion. The UM series gives up a lot of motor force and costs more though. Nobody really makes a 10" or 12" like I'd like to see.

Excellent work. The response looks very good. No surprises.

Hello... I would start by defining a few things that will help others give you advice. Budget? Room size shape? Maximum size / dimensions available for the subs? Multiple locations available for the sub? How loud do you plan to listen? Rock concert levels or more modest typical home playback levels? What experience do you have with powerful bass systems? What is your reference for the sound you want?

Sounds good Phil. Feel free to post measurements or listening impressions of your sub.

Chiko, I'd suggest putting some damping in there behind the drivers. It should clean up the top end a bit and "tighten" the sound.

Very cool. I'm sure that TH will move some air. What's the low corner on it?

Jordy, The 21Ipal is good as well but if you ever want to run a single cab it will be hard to find an amplifier that likes the 1ohm load. If you have a good price on 4 and the impedance will work for you go ahead. The semi inductance for some of the drivers that you listed are shown on the driver testing page on the main DB website. Yes that HR input is the current "best" match at least until I can get a cab tested.

Sure. All of the files are available in the first couple of posts. Welcome to the forum. 🙂

My recommended driver for these is the Eminence NSW6021-6.

Looks like great work Hunsbedt! Good job.

Either of those woofers are excellent. The NSW is a lot cheaper here and the impedance is much easier to match amps to with a single or dual drivers. Performance wise the 21Ipal is a bit more efficient and may have a very small edge in power handling because of it but it's probably not enough to be audible. Both are absolutely top tier drivers. I own both. Either company is large enough and well established that any sort of mfg defects will be taken care of. There have been some reported issues with both drivers. It happens.

Ha! Quite the understatement I'm sure.

Amp looks great Peniku.

I've run plenty of series or series parallel cabs too. Keep the cables as short as possible and use a heavy gauge. Keep the drivers the same model and loading. It'll be fine. There are untold amounts of cabs wired or run in series everyday. Three 4 ohm 21sw152's in parallel is probably going to be a min impedance of about 1.2 or 1.3 ohms. The SP amps will "do" it. Might be a smidge low for them but they've run 2 21 Ipal's in series. which is roughly 1.4 or 1.5 ohm.

Hello Cam, To add a bit more to Kyle's post, group delay is WAY over rated when it comes to subwoofers. Lower is better make no mistake but the perception of it at low frequencies has not been shown to be very audible unless it gets very bad. Studies have shown that as frequency decreases we are more tolerant of large GD and it is much more difficult to distinguish. Personally I don't worry about it below 30Hz. 20ms at 50Hz is probably not worth worrying about. 20ms at 200Hz on the other hand should be quite audible. This is why group delay is often represented as a percentage of a cycle vs frequency. With subs I only have concern if the delay is not uniform (spikes, sudden increases in certain frequency bands above 30Hz, the delay exceeds 1.5 cycles > 30Hz, or a combination of both. If the GD is relatively smooth over the primary bass range and remains below 1 cycle I don't worry about it. Room acoustics tend to do horrible things to the time response at the listening position that dwarf the native GD of the sub anyway.

Hell yeah Jay. Looks awesome. Probably sounds alright too. 😏

That's certainly plenty of headroom. What is your amplification for the different subs?