My other gear is Denon 3313, Klipsch Reference MK II (82, 62, 52), Klipsch SUB-12 (Which I will replace with the DIY sub), and BFD. I am listing down the TS parameters for this sub;
Alpine SWR-1223D T/S Parameters
Fs = 28 hz
Vas = 43 L
Qts = 0.47
Qms = 0.50
Qes = 8.5
Re = 1.85 ohms + 1.85 ohms
Xmax = 20 mm
Peak-to-Peak Excursion = 72 mm
Sd = 480 cm sq
Pe = 600 watts
SPL = 85dB
Can anyone help me design a proper box for it may it be ported or sealed??
If this goes well, I will make another one also. SUb choices are pretty much limited as I am in Pakistan. I want scary bass both for movies and music with the 70:30 ratio respectively
with a ported, you need a high pass filter around 20hz or so. most plate amps come with something like that built in, so the excursion won't blow up as in the model.
Basically, what I'm trying to say is that if you're only building one 12" sub box. I think that you're going to be pretty disappointed if you build the sealed design as it won't have the output that I'm sure you're looking for but it'll roughtly cost you an additional $200 american dollars (the cost of a MiniDSP) to build a ported design.
BTW, don't forget to add a HPF to your ported model so that way you're making a proper informed decision.
Also, I modelled a 3.5 cu ft ported box tuned to 18Hz with 600 watts of input power having a slot port with the dimensions (H x W x L = 1 in x 16 in x 34.5 in). Pls have a look at the graphs. The Xmax is within limits down to 16Hz. Also note, my room is on the smaller side i.e. 2500 cu ft.
Cone Excusion With 600 Watts
SPL With 600 Watts
SInce you are using Crown XLS2500, could you pls let me know how much RMS power XLS1000 puts out at 4 and 2 ohms both in stereo and bridged mode?? Crown ratings are specified at 1 Khz.
Another important question, how do I limit the amp (XLS1000) to pump out only 600 watts in bridged mode at 4 ohms???
Again, I'm not as educated on these things as other people I'm just rying to give you whatever knowledge that I might have.
Running a ported sub without a high pass is pretty risky for home theater I think. Unless you know that specific movie you are about to watch doesn't have any content below 20hz and be careful of the volume knob. There are a few movies that go down to 10hz but those are pretty rare, I can only think of Hulk right now. I use a Denon 2312 with a EP2500 and puts out more than enough volts. The gain knob on the amp is set to about 1/4 of the way. I measured the lfe output with a multimeter and I was able to get 4.8v with the sub output at +12. You can test this yourself, find a 60hz test tone and measure the lfe output with a multimeter.
I am using ART CleanBox Pro to match pro amp level . Btw I had Onkyo 809 that put out a paltry 200 millivolts. So switched to denon 3313. Its pre voltage is better than onkyo but still underpowered for the xls1000. Anyway thanx loads for your help and prompt replies.
I think 4.8 Volts from sub pre-out with the sub level at +12on AVR doesn't mean anything and translates to not more than maximum 0.7 volts at 00 sub level on avr at normal listeing levels. I think your behringer is still under powered. I checked it with my multimeter, the sub pre out level with sub level at 00 on the avr (Denon 3313)at 75dB volume before using ART CleanBox Pro was only 1 volt. After inserting Art CleanBox Pro and keeping the gain knob at 12 o clock (mid position), I measured it at 6.7 Volts keeping every other setting the same.
Get a Samsung S-Convert or Art CleanBox Pro
yes. "input sensitivity" on pro amps means the amount of voltage necessary that must be provided by the receiver into the pro amp in order to hit the rated max output of the pro amp.
example: let's say an amplifier "amplifies" the input signal by 40 times and has a maximum output signal of 60 volts. you would need to put in 1.5 volts in order to get the full potential of the 60 volts output. if you only input 0.5 volts, then the amp can only boost it to 20 volts, which is below its capability.
"input sensitivity" is not a very intuitive concept for a person new to all of this, so it is a good question.
- Set the master volume on AVR at my reference listening level (75dB on SPL meter) with all the speaker trim levels at 00 on the AVR. The volume on master dial read -6dB on reference scale. For level setting, I used a wideband pink noise that covered the frequencies from 60hz to 90hz.
- Then I disconnected all the speakers and the DIY subwoofer.
- I added ART CLeanBox Pro in the sound chain by hooking sub out of the avr with rca cable and set the input level on it to the max.
- Set the master volume at -6dB on AVR and and output level on Crown XLS1000 all the down to its lowest position.
- Ran the same wide band pink noise that was used to set the speakers levels and slowly raise the level attenuators on XLS1000.
- I left the output gain knob where the clipping LEDs lit constantly. This was at 12 o clock position.
- Then without changing any other setting, I checked the output vlotage of the Art CleanBox Pro and it was 6.7Volts.
- Then I hooked up the DIY sub and ran internal test tone for the sub from the AVR. Before checking the sub level I set the master volume on the avr to -6dB keeping every other setting the same and measured the sub level on SPL meter. It read 80dB, so, then I set the sub trim level to -2.5 on the avr so that I get 78dB on the SPL meter.
I have a feeling I'm doing it all wrong lol. If I get 1.4 volts at 0db, my subwoofer trim should be at 0 or close to it, not -5. I found this guide with lots of information which I have to try out one day.
I don't go beyond -15 max on the master volume with the speaker trim levels 00 on the avr for at least the front three speakers. So, in reality I am listening at 66dB. For action movies, this is plenty loud keeping in mind you will get transients of 20dB in short bursts. So, during transients, that would be 86dB. And mind you LFE is a separate track in 5.1 input stream, which is already 10dB hotter than all the other channels. So, you wiill be hearing transients in LFE at 96dB.
There is a reason why I do not cut the trim levels down to -9, -8 dB. If you let Audyssey or any other auto eq program to set the system, it sets your system keeping the master volume at 00. That's the reason why we get channel trims to around -8, -9 dB at listening position. Normally ppl sit 10-12 feet from the screen and speakers. I do not do this coz it kills the dynamic range of the system.
If the speaker trims are 7-8 db below the reference, then keep in mind that the redirected bass is also 7-8 db below the reference. Whereas the LFE that is separately mixed is 10dB hotter. So the difference between redirected bass and LFE is close to 17dB.
The net result is that you get weaker redirected bass and you try and bump up the bass to get it stronger. So, although you get stronger redirected bass, but it sends the separate LFE channel off the chart resulting in boomy bass or the sub bottoming out when LFE is also played with the redirected bass (which is derived from the main channels so it has the same level as the signal in speakers).
Bear in mind when we bump up the sub level in avr uptill 00 trim level, we are not increasing the bass. We are just letting more redirected bass flow into subwoofer which is already present in the recording mix. Imagine it as a valve on a water pipe. The valve does not produce extra water. It can only let as much water flow out of it as it is there inside the pipe. So the key is to preserve the maximum signal by keeping the speaker trim levels close to 00 on avr and set the system at 75dB with master volume manually.
Just my opinion
The internal pink noise signal is -30dB from the potential output a main channel may be asked for and for the sub channel -40dB from the potential output. If considering redirected bass from 5 main channels as well this signal is -48dB lower than the potential maximum signal strength. A VERY weak signal compared to what you experience with actual movies or music and intentionally so. Pink noise at even 75dB is very annoying that is partly why the calibrations signals are very much reduced in level.
If a 75dB signal requires 1v from the output... A maximum level 123dB signal out of the SW jack at REF level will require >250 volts. This is equivalent to an increase of 63,100 x the power.
You should never use the internal pink noise signal for calibration to determine if your pre-pro/ receiver has enough voltage for your amp to reach full output. It is far too tepid of a signal. Even with the master gain maxed out and the channel trim maxed out it will still be about 20dB weaker than the potential that is there in movies. Your receiver output will be far from clipping at this output. Whatever signal is used should be strong. A 0dB sine wave tone input into the system instead is much better. You are testing for maximum voltage like when a bomb blows up in Batman and you have it cranked and whether your receiver is going to clip without the amp getting enough juice to produce full power. What you are not testing for are the tiny voltages that occur when the weather channel is on at -40dB on the master dial. Should your 2000w pro amp be slamming your subs and clipping when watching the weather channel at -40? Of course not so why would you expect to get this result with such a signal? If you are judging this stuff on the basis of the internal calibration noise in the receiver this is essentially what you are doing. You want to push the preamp output with a very hot signal to the point that it is clipping and see if that is enough to get the amp into clipping. Usually the amp will have run into clipping long prior to the receiver hitting clipping and the amp can be run with the trims turned way down indicating absolutely no reason to use a booster. I have never needed one with any pro amp or receiver I have used and there have been a LOT of different brands.
Of course signal boosters boost the signal. That is exactly what they are designed to do. That does not mean that they are needed in most cases. They also will boost any hum or line noise as well so if you do not need more clean voltage than the electronics ahead of it in the chain can provide you are only degrading the signal by introducing it.
I only mention this because i have seen a lot of guys make this mistake. Moral of the story is that you need to determine the maximum output potential of the preamp output. This is why this should always be done with all speakers disconnected. if you stop prior to either amplifier clipping or preamp output clipping you do not know if you have enough voltage or not.
. Moral of the story is that you need to determine the maximum output potential of the preamp output. This is why this should always be done with all speakers disconnected. if you stop prior to either amplifier clipping or preamp output clipping you do not know if you have enough voltage or not.
What's a good way to identify the max clean sub signal output the AVR is capable of? How do I tell that the preamp is clipping?
All speakers should be disconnected or off during this. All EQ should be disabled dynamic, Audyssey, external, etc...
If you have other devices between the receiver and amp such as a minidsp or a Dcx. You move onto these after the receiver one at a time until you get to the amp. You should maintain the strongest clean signal you can up to the amplifier. The amplifier should clip first before anything else. Again avoid adjusting any input or output trims after this is done except for the receiver settings.
When EQ is enabled things get more complicated. If it is in the first unit in line the receiver you need not mess with anything. If it is after the receiver you may need to adjust the input and or output trims for the device doing the EQ. Boosting is not what you have to worry about so much it is cutting which will allow the input to clip on the device EQing prior to the output producing enough voltage to clip the amp. So if you have a deep cut it is then possible to clip the EQ devices input prior to getting full power from the amp. At this point after EQ in an outboard device you can run its output into the sc and Measure the EQd response shape of the outboard EQ device only! to determine how much cut is there and increase the EQ devices output by a corresponding amount. This last part is not necessary if you have more than enough headroom that you will be very unlikely to need it. It is only needed if you want to be able to get EVERY scrap of output the system is capable of at any frequency.
I built a roughly 50L sealed box to test my sub and took the FR in REW. Pls have a look at the WinISD modelled FR and compare with the actual room response. They do not match at all. I am surprised at the low extension. The roll off starts at 16hz. I tripple checked it in rew. But this is how it is.
Can someone tell me what wrong am I doing here?? I am skeptical coz Crown goes into clipping, which never happened before and listening experience is way below par. I mean looking at the room response, I feel elated but listening is just not good. Maybe crown doesn't have enough power to match the projected in-room response or God knows what.
The sub doesn't bottom out but sends crown into clipping even at 15dB below reference during 20dB transients. It just does not have any punch. Can someone help?
WinISD Modelled Response
In-Room REW Response
I am not using more than 4dB of gain on 2-3 filters in BFD, rest all are cuts. Do you think Crown XLS1000 is running out of steam??
I am planning on getting Behringer iNuke3000 DSP Amp coz it has a floating point HPF and the lowest setting is 20Hz. I can use this amp for my ported builds. Is this amp any good?? I've heared the fans on these models are noisy. Which fan do i buy to replace?
winisd is a 2pi space model...as if you were measuring a sub in an open field.
rooms have modes, boundary gain, and pressure vessel gain depending on the dimensions and the construction of the room.
the thiele small parameters that underlie winisd are not meant to predict room effects, just roughly the effect of a driver in an enclosure.
Why does crown go into clipping at even 15dB below reference? Does it mean the amp runs out of juice?? How about Behringer iNuke 3000 DSP??
Pls guide me on this.
I am running Crown in bridged mode (1100 watts at 4ohms "1KHz"); but still it is unable to hold even at 60hz. That explains why i get no punch. What do u guys think???
Also, I have ordered Behringer iNuke 6000 DSP model. Any thoughts on this amp??