Recently having driven the crown XTI4000 at 8 ohms stereo and 4 ohms mono most assuredly resulted in some of the worst sound I've heard using the exact same speaker into the lower impedance with the same speaker cable. I couldn't believe the difference. It wasn't subtle. The amp rated >500 for its damping factor didn't save it from poor sound. In my car, I can configure my TC sounds sub for 1 or 4 ohms and it was even worse there.
I guess in my two cases it fits the range of making a big difference.
yea, these switch-mode supplies seem to be junk on PA amplifiers.
No bass .............
Probably because either they cannot source current due to lack of transformer/caps, or maybe they cannot push current into the high impedance spike right within a sub-woofer's operating band.
Car amps seem to be doing it well, then again maybe they aren't. The prodigious bass is from the free 10-20db boost as you go below 100hz in a vehicle, not because the amplifier is a stellar bass amplifier.
Norman
No bass .............
Probably because either they cannot source current due to lack of transformer/caps, or maybe they cannot push current into the high impedance spike right within a sub-woofer's operating band.
Car amps seem to be doing it well, then again maybe they aren't. The prodigious bass is from the free 10-20db boost as you go below 100hz in a vehicle, not because the amplifier is a stellar bass amplifier.
Norman
Hi,
Spinmonster, the soundquality for sure had nothing to do with the amplifiers damping factor, or better expressed, it' output impedance.
Most amps are configured as voltage sources and get into trouble if load impedance drops too low. With very low impedance speakers a current amplifier would be feasable.
jauu
Calvin
Spinmonster, the soundquality for sure had nothing to do with the amplifiers damping factor, or better expressed, it' output impedance.
Most amps are configured as voltage sources and get into trouble if load impedance drops too low. With very low impedance speakers a current amplifier would be feasable.
jauu
Calvin
Hey guys,
Sorry I hadn't responded lately; been pretty busy.
Thanks for all the input; big help when it came to explaining what I should shoot for in regards to GD, port velocity etc. I think that helped more than the driver recommendations. Now I can use the modeling software to work it out for myself in the future.
It sounds like I really couldn't go wrong with any of them. The Dayton HF-12 doesn't sound like the best option for me though. Needs an enclosure as big as a 15". I'm going to pick-up the HO-15. If I absolutely had to go with a smaller enclosure I'd choose the tc12. Now, I can't decide on 300 or 500 watts. Looks like the HO will definitely like more power, but I don't know if I need it... hmm.
Thanks again
Evan
Sorry I hadn't responded lately; been pretty busy.
Thanks for all the input; big help when it came to explaining what I should shoot for in regards to GD, port velocity etc. I think that helped more than the driver recommendations. Now I can use the modeling software to work it out for myself in the future.
It sounds like I really couldn't go wrong with any of them. The Dayton HF-12 doesn't sound like the best option for me though. Needs an enclosure as big as a 15". I'm going to pick-up the HO-15. If I absolutely had to go with a smaller enclosure I'd choose the tc12. Now, I can't decide on 300 or 500 watts. Looks like the HO will definitely like more power, but I don't know if I need it... hmm.
Thanks again
Evan
It seems like there are downfalls to the pro amp though. No auto-on, fan noise, no high pass... anything else? How do you deal with these issues?
Evan
Well, there is the fan mod to a quiet fan. I have no idea about auto on. High passing mains can be done by running them sealed (plugging ports) or a PLLXO if you have a separate amp, or a speaker level high pass. Overall though, I would try to not under power a sub if you can avoid it.
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Real enough.......a nu6000dsp is more capable than a crown XTI4000 for 2/3rds the cost.
Hey, resurrecting an old thread here. I got bogged down over the summer, but now I'm ready to build. I bought the Dayton RSS390HF. It will go in about 4.5ft sealed. I think this is a little different than what I was originally thinking.
Now, I was about to pull the trigger on the Dayton 500W plate amp with peq, but then I started second guessing my decision. The dayton is on sale right now for $210 and I've found both the inuke 1000dsp and 3000dsp for around the same price. I'd like the option to add a second 390HF down the road, but I'll just buy the plate amp if it's the best option right now. I do like the dsp on the inukes though as I'll be running it from my two channel amp and not my receiver so no bass management.
My problem is the Behringer 1000dsp appears to only have 210 watts rms/channel @ 4ohms. My sims show this not to really be enough especially if I eq to flat around 20Hz.
The 3000dsp may be too much at around 700 watts @ 4ohms and of course it's the most expensive. If I don't need it I'd rather not pay the premium. Sims show xmax +10% around 500W and under 200W eq'd.
I've asked about this at Hometheatershack, but I'm getting pretty minimal help. So, could somebody please respond with some decent in depth help. I want to place the order today before I lose the nice prices and I'd like to start building after Christmas.
Sorry for the long response, but I want to make a good decision; I don't buy things and consider them throw away if they suck because they're "only" $300
Thanks for any help
To anyone interested
Good deal on Behringer NU3000dsp. New in box, full warranty and authorized dealer
I payed $235 with free shipping, but maybe they could be had for a little less.
They don't seem to have many left
Behringer NU3000DSP Inuke 3000 Watt Power Amplifer w DSP Control USB Interface | eBay
Hope this helps someone
Good deal on Behringer NU3000dsp. New in box, full warranty and authorized dealer
I payed $235 with free shipping, but maybe they could be had for a little less.
They don't seem to have many left
Behringer NU3000DSP Inuke 3000 Watt Power Amplifer w DSP Control USB Interface | eBay
Hope this helps someone
Nice, the sub/woofer will need about (w/no EQ) ~200 W/4 Ohms sealed vs. ~600 W/4 Ohms BR (comparing the power). You will need that extra for the excursion dB's@LF <30Hz. Let's see if its quality it's the expected (amp). It's good for a second sub (NU3000DSP).
Maximum Output Power 4 Ω per channel, stereo 820 W, Output circuit type Class D, Distortion <0.3%, Frequency response 20 Hz to 20 kHz, +0 / -1 dB
Minhembio.com - Hemma hos MrLelle - Sonosub -Typ SVS 12 Plus DSP
Maximum Output Power 4 Ω per channel, stereo 820 W, Output circuit type Class D, Distortion <0.3%, Frequency response 20 Hz to 20 kHz, +0 / -1 dB
Minhembio.com - Hemma hos MrLelle - Sonosub -Typ SVS 12 Plus DSP
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Looks like the the 390Hf can take about 300W with no HPF before excursion issues. I know the BR will take more. I figured it's good to have extra and not push the amp to distortion rather than buying an amp that will just reach xmax at full power. NU1000 wouldn't even reach xmax at full power into 4ohms. Plus, I think with the extra power, the NU3000 is more suited to adding any boost that the 210W NU1000.
Yes, the NU3000dsp has some versatility that the plate amps don't. Mainly, possibility of a second sub and more peq bands, plus upgrade path to more power hungry woofer/alignments in the future.
That's a screaming deal, good call. Might have to pick up one myself.
The nu3000dsp is a beast, my friends got one for their 500 ft^3 party room on my recommendation to run some 1985 vintage klipsch forte's. Three way with two horns, 12" w/PR, 4 ohms nominal impedance, dips below that, and uses an autoformer in the crossover which makes for a tricky inductance. The amp hasn't ever even blinked at driving it, going full output for hours. Used the dsp to put a nice rise on the mid-low bass and then a hard high pass around 30hz. When run with a good source, it sounds exceptionally good, any gets really, really loud.
Based on your original post and goals, I would strongly recommend that you build the largest volume ported box(es) that you can creatively fit into your room, with a tuning in the 15-20 hz range. The 3000 will effectively power a pair of the HF's in larger ported boxes. Large low tuned boxes will perform like an infinite baffle above 50-60hz (VERY clean), while there is really no concern about group delay in the low bass coming from the port. I've taken my pair of 15 HO's, plugged the ports and boosted them down to 20hz, and maxed them out getting convincing HT performance in a room 2/3rds the size of yours. You need a low tuned ported box if you want real room shaking HT performance, which really makes no compromise with music if done right.
Keep in mind that getting a sub to properly integrate with mains is much more about time alignment and crossover than actual sub performance.
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Hopefully it all works out with the amp. I'm usually pretty wary dealing with companies I don't know. I'll usually pay more for good service and piece of mind. They do have a lot of reviews on ebay though
Man, don't tell me that!! I was all set in my mind. I do like the sound of ported subs if they're done right. The sound I'm trying to get is smooth and low. I really want smooth and effortless bass, no rumble, no mud, clean and low distortion. If that means adding another or two then so be it, of course I'd like the first one to sound good on it's own. But, the HF models in a huge ported box, which is usually telling you that they're meant for sealed. BTW, the HF does have more extention and I think a bit more xmax than your HO's FWIW.
For the first one, I have the room for a large ported box, but the other locations I have available won't accommodate more than about 120L. I'm pretty limited as my significant other says the room's already "too cluttered".
Why would two 15's have such a hard time with HT in such a small room(yours)? Is the sealed alignment really sucking that much of the life out of them? Above 30Hz the output looks about the same and below tuning the sealed HF will play louder lower. around tuning vented obviously has the advantage. BTW, with the inuke, I don't have a high pass available below 20Hz; how would I tune sub 20 without a high pass? Just be careful.
Here's the transfer function of the 15HO ported (gray), 15HF sealed (green) and 15HF sealed with boost at 21 (yellow). Of course this doesn't tell the whole story; the eq'd HF is xmax limited to 110db, no eq HF to about 112db and HO will just get crazy loud- north of 116db. It does show more output down low for equal watts though. This doesn't show HPF on the ported HO. With that in it drops off well below the HF's.
Not trying to be combative, but you're throwing a wrench into my perfect little plans... and I don't like it
What do you think man? I'm still open for suggestions. Better now than later.
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The batch at the above link sold out. Here's the new link with four more available.
Behringer NU3000DSP Inuke 3000 Watt Power Amplifer w DSP Control USB Interface | eBay
I offered $235 and they accepted. I saw with some peoples offers the company counter offered. If anyone is interested, I'd offer under $235 and see what happens. Maybe as low as $200.
There's also a listing for NU1000dsp for something like $169 with free shipping from another company
Cheers
Behringer NU3000DSP Inuke 3000 Watt Power Amplifer w DSP Control USB Interface | eBay
I offered $235 and they accepted. I saw with some peoples offers the company counter offered. If anyone is interested, I'd offer under $235 and see what happens. Maybe as low as $200.
There's also a listing for NU1000dsp for something like $169 with free shipping from another company
Cheers
I'm not on my computer with horn resp or winisd, so I can't really run any sims for you. Here's a good thread with a comparison between a pair of sealed HF's and a large ported:
Dayton HF Reference 15" enclosure (no THT for me)..
I'm just of the overall opinion that sealed boxes are not an efficient design if you want low extension.
As far as the HF vs. HO, from what I understand the main difference is the weight of the cone, the HO is stiffer and heavier, thus it will typically model better in smaller ported boxes. The HF has 2mm more xmax and thus nominal output, but they both have an xmech in the low 20mm range. When I plugged and boosted my HO's, I was running well above xmax, probably in the 15-18mm range on low bass effects (Transformers movie), and still sounding very clean. Xmax vs. distortion is more relevant in the midbass and midrange, for subs in 20-40hz range, going a bit beyond xmax on low power (such as in a low tuned box) any distortion is really not going to be noticeable.
I like the 8 ft3 17 hz design from the link above, if you can figure out how to fit a pair of those, they would be very capable in your room and easy to EQ for a nice curve for HT use.
All the designs discussed will be virtually identical for music, but need proper setup to sound good.
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Hey, thanks! I hadn't seen that thread. I took a look, but I'll have to read through it later. Sound be interesting.
The HF also has an fs of 18 vs 24.2 for the HO.
I know that sealed is not the most efficient for low end output. I modeled the HF in a large ported box too and it's extension is impressive. I just wanted to try a sealed design and the numbers don't look bad to me. I know that ported subs, and speaker for that matter, if done right with good drivers can be musical. That was never why I was going with sealed.
I don't have a lot of experience with sealed subs and punchy bass is not really what I'm after. My mains have very nice bass on there own and an f3 of 40Hz (I plan to just stuff the ports and run them full range) so they can handle the 50Hz and up stuff. I just want smooth rich bass. Is sealed not the right alignment to get this?
I can put a second large ported box at the other end of my room, but I've never had a sub there so I don't know how it'll sound. (my room is a 22'x12' rectangle with a cubby for a desk that's about 5'x6' with all the audio/HT gear along the long wall at the end with the cubby) Hope that makes sense. Anyways, I just sold my sub I can't try it first. There is no room for a large sub anywhere near my tv/main speakers.
The first sub will go almost in the office cubby behind the couch. This is where I've found the smoothest response at the seating positions in my room.
Near the front L/R isn't great. One side has a suckout at the seating pos. the other is in a corner and sounds strong but bloated.
Anyways, I'll read that thread and give it some thought. I may try the sealed in an unfinished box and if I'm not happy build the large ported one instead. MDF is cheap and I have the tools and skill to slap a sealed box together in an hour or two.
Thanks again
Okay, I read through that thread. It was a little inconclusive. Seemed like most of the guys on there were for dual sealed and the OP went with vented. Never posted any results. Personally in a room his size I would say one or two vented, but his room is about 50% larger than mine.
Here are the plots of the HF in ported (250L), sealed (125L) and sealed (125L) with eq applied (3.25db at 20Hz). All modeled with a single driver
Without a highpass filter the ported HF has amazing extension, but no protection and has the same output (xmax + about 10% limited) as the sealed version. With the HPF in place at 20Hz, which is what the NU3000dsp can do, the output is a good few db higher, but the response is pretty close to that of a the sealed HF with eq.
So the decision seems to be between:
HF vented-HPF @20Hz. More output with the same extension as sealed, Large box and I may not be able to add a second one due to size constraints.
HF vented-no HPF. More extension, but same output as sealed. Large box and no protection on the woofer.
HF sealed no eq. Smaller box, multiple subs possible. About the same output, but with much less extension than vented with no HPF
HF sealed with EQ. About the same extension, but less output than the ported box with the HPF. Smaller box.
Here are the plots of the HF in ported (250L), sealed (125L) and sealed (125L) with eq applied (3.25db at 20Hz). All modeled with a single driver
Without a highpass filter the ported HF has amazing extension, but no protection and has the same output (xmax + about 10% limited) as the sealed version. With the HPF in place at 20Hz, which is what the NU3000dsp can do, the output is a good few db higher, but the response is pretty close to that of a the sealed HF with eq.
So the decision seems to be between:
HF vented-HPF @20Hz. More output with the same extension as sealed, Large box and I may not be able to add a second one due to size constraints.
HF vented-no HPF. More extension, but same output as sealed. Large box and no protection on the woofer.
HF sealed no eq. Smaller box, multiple subs possible. About the same output, but with much less extension than vented with no HPF
HF sealed with EQ. About the same extension, but less output than the ported box with the HPF. Smaller box.
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