Members RoboPimp Posted August 12, 2004 Members Share Posted August 12, 2004 I'm looking at subs, what's an acceptable frequency response? I am looking at one that says: Frequency Response1 Meter On- AxisSwept-Sine in AnechoicEnvironment:49 Hz to 300 Hz ( Link to comment Share on other sites More sharing options...
Members RoboPimp Posted August 13, 2004 Author Members Share Posted August 13, 2004 I'm not looking for world class chest crushing bass, just a nice thump. Will this cut it? please help the foolish person Link to comment Share on other sites More sharing options...
Members OMNIFEX Posted August 13, 2004 Members Share Posted August 13, 2004 They should work if the specs are true. What are they anyway? Link to comment Share on other sites More sharing options...
Members Centauri Posted August 13, 2004 Members Share Posted August 13, 2004 One thing the specs never tell you is harmonic distortion generated at various frequencies and power. With the box tuning at 42Hz and -3dB at 49Hz, then I would suggest harmonic distortion to be an issue below 50Hz as speaker loading drops off. The stated usable limit probably is not really usable due to the muddying up of low mids when pushing a bit of volume. I would recommend a high-pass filter at 50Hz, and they may work well. Best thing when considering these type of subs is to actually hear them in operation, but not always possible. Cheers Link to comment Share on other sites More sharing options...
Members RoboPimp Posted August 13, 2004 Author Members Share Posted August 13, 2004 * 3/4 inch plywood finished with durable black polyurethane coating* 800 Watts continuous* 1600 Watts of program power* 3,200 Watts peak* Extremely low frequency response down to 35 Hz* Response: 35 Hz to 1.5 kHz (+/- 3 dB)* Impedance: 8 Ohms* Sensitivity: 95 dB (1W at 1m)* Neutrik Link to comment Share on other sites More sharing options...
Members Centauri Posted August 13, 2004 Members Share Posted August 13, 2004 If you gave us brands and models numbers, then we may be able to give you more info based on our experience with these boxes. The published specs are only part of the story. Cheers Link to comment Share on other sites More sharing options...
Members RoboPimp Posted August 13, 2004 Author Members Share Posted August 13, 2004 Sorry, these two subs are the peavey SP 118 and Impulse 115 respectively Link to comment Share on other sites More sharing options...
CMS Author Craig Vecchione Posted August 13, 2004 CMS Author Share Posted August 13, 2004 No way the 800w continuous is accurate for the Impulse 115. Id say more like 400w and this coupled with the 95dB efficiency might be what make it a somewhat weak-sounding sub in my opinion. But for a 1x15 we can't expect a whole lot. In my estimation you'd be as well off by buying a 15" three-way full-range box. The SP118X is a pretty good sub for the type and the price is right...usually about $450. The 3dB additional efficiency make much better use of power. I would also consider this to be a solid 400w box. Link to comment Share on other sites More sharing options...
Members RoboPimp Posted August 13, 2004 Author Members Share Posted August 13, 2004 Originally posted by Craigv No way the 800w continuous is accurate for the Impulse 115. Id say more like 400w and this coupled with the 95dB efficiency might be what make it a somewhat weak-sounding sub in my opinion. But for a 1x15 we can't expect a whole lot. In my estimation you'd be as well off by buying a 15" three-way full-range box.The SP118X is a pretty good sub for the type and the price is right...usually about $450. The 3dB additional efficiency make much better use of power. I would also consider this to be a solid 400w box. The SP118X is the MDF one, I'm looking at the newer version. The impulse 115 has peavey's new "lowrider" speaker. Supposedly handles what they say. I'm leaning towards the SP118 too, I can get it for about $380 bucks. Good deal in my opinion. Link to comment Share on other sites More sharing options...
Members agedhorse Posted August 13, 2004 Members Share Posted August 13, 2004 The lowrider is a decent driver... it has a slightly longer voice coli winding height than is typical on a 15" which helps with power handling and high powered THD but is offset by decreased sensitivity. At some point, the decrease in sensitivity matches the increase in power handling yielding no gain. edited for missing line! Link to comment Share on other sites More sharing options...
Members RoboPimp Posted August 13, 2004 Author Members Share Posted August 13, 2004 Originally posted by agedhorse The lowrider is a decent driver... it has a slightly longer (excursion?) than is typical on a 15" which helps with power handling and high powered THD but is offset by decreased sensitivity. At some point, the decrease in sensitivity matches the increase in power handling yielding no gain. so, can you tell from the specs I've given you which one of these would perform better? The SP118 handles 600 watts continuous. Link to comment Share on other sites More sharing options...
CMS Author Craig Vecchione Posted August 13, 2004 CMS Author Share Posted August 13, 2004 Originally posted by RoboPimp so, can you tell from the specs I've given you which one of these would perform better?The SP118 handles 600 watts continuous. I thought something seemed odd when I saw "3/4 plywood"....I was thinking of the Impulse sub in the molded plastic box, which is a pretty anemic sub. So I haven't heard the 115 for comparison with the SPX. Give it a listen....a plywood box alone gives it a leg up in my book. Link to comment Share on other sites More sharing options...
Members agedhorse Posted August 13, 2004 Members Share Posted August 13, 2004 My guess it that they would be pretty comprable, but if the sensitivity difference is accurate then you would need a significantly bigger amp (more $$$) to drive to the same SPL. Link to comment Share on other sites More sharing options...
Members RoboPimp Posted August 13, 2004 Author Members Share Posted August 13, 2004 Originally posted by agedhorse My guess it that they would be pretty comprable, but if the sensitivity difference is accurate then you would need a significantly bigger amp (more $$$) to drive to the same SPL. ok... This makes sense. Does it seem possible that w/ this significantly bigger power source the impulse 115 would perform as the specs say with the low end being at 35 hz +/- 3 db as compared to the SP 118 which gives 49 hz @ +/- 3 db. How much difference does that extra 14 hz make I guess is what I'm asking (if the specs are legit) It's possible for a 15" to outperform a 18" right? The 15" is more expensive and supposedly a better driver. I would like to sound check them, but I doubt that I would be able to really tell the difference in a store environment. Unless I could get someone to set their drums up in there and give the kick drum a check. heheh. Link to comment Share on other sites More sharing options...
Members agedhorse Posted August 14, 2004 Members Share Posted August 14, 2004 No question that it's possible for a 15 to outperform an 18. I wouldn't base my expectations on the power handling stated in your specs. My experience is that the drivers do not hold together at 3200 watts peak unless it's a very short peak. That's true of all commonly available drivers from all manufacturers, not just this example. That's why needing twice the power to make one driver equal to another is significant. Link to comment Share on other sites More sharing options...
Members sandasales Posted August 15, 2004 Members Share Posted August 15, 2004 Originally posted by RoboPimp I'm looking at subs, what's an acceptable frequency response? I am looking at one that says: Frequency Response1 Meter On- AxisSwept-Sine in AnechoicEnvironment:49 Hz to 300 Hz ( Link to comment Share on other sites More sharing options...
Members dboomer Posted August 15, 2004 Members Share Posted August 15, 2004 Originally posted by RoboPimp I'm not looking for world class chest crushing bass, just a nice thump. Will this cut it? please help the foolish person Maybe the problem here is there are subjective descriptions and empirical ones. "Chest chrushing" and "nice thump" don't really have numbers. Why not go out and find someone that is doing what you want to do, where you want to do it. See what works for them in that situation. Then maybe you can look up the numbers for that gear and compare it to these. Link to comment Share on other sites More sharing options...
Members Kennykeys Posted August 15, 2004 Members Share Posted August 15, 2004 A kind of related blurb from another thread;."With subs, the lower you go, the more amps/power/big boxes you'll need to reproduce those really low frequencies. Plus, the lower frequencies are more demanding of the driver itself. Remember that the fundamental frequency of most kick drums is around 60-80 hz. And, bass guitar sound is mostly made up of the upper harmonics, not the fundamental. .So, yeah, that 30-40hz range is really neat to hear/feel that extra-low oomph of sub-harmonic air, but it sure is expensive. Depending on the cabinet, common cut points for 18" subs often range from 30hz to 40 hz. Personally, I High Pass Filter my band's single 18 club subs at 45hz, and we still get PLENTY of sub kick. Yes, the kick does sound a little different when I compare it with a 20hz HPF, but it sounds OK to me at 45hz and I figure that I'm conserving amp power (and driver life) to be used where I really want it concentrated ( at 50-100hz.) I'll leave the under 40hz zone to the concert rigs.....let them muddy up some cow barn arena." Link to comment Share on other sites More sharing options...
Members RoboPimp Posted August 15, 2004 Author Members Share Posted August 15, 2004 Originally posted by dboomer Maybe the problem here is there are subjective descriptions and empirical ones. "Chest chrushing" and "nice thump" don't really have numbers.Why not go out and find someone that is doing what you want to do, where you want to do it. See what works for them in that situation. Then maybe you can look up the numbers for that gear and compare it to these. good point, the biggest local place that I play we covered with one SP118. It seemed fat but just a little bit lacking, so two would probably cover all that I could need. I guess I'll start trying to factor that into the budget. Link to comment Share on other sites More sharing options...
Members dboomer Posted August 15, 2004 Members Share Posted August 15, 2004 That, then, sounds reasonable to me. Link to comment Share on other sites More sharing options...
Members agedhorse Posted August 15, 2004 Members Share Posted August 15, 2004 Originally posted by Kennykeys Personally, I High Pass Filter my band's single 18 club subs at 45hz, and we still get PLENTY of sub kick. Yes, the kick does sound a little different when I compare it with a 20hz HPF, but it sounds OK to me at 45hz and I figure that I'm conserving amp power (and driver life) to be used where I really want it concentrated ( at 50-100hz.) I'll leave the under 40hz zone to the concert rigs.....let them muddy up some cow barn arena." If you run Xmax calculations on common sunbs it's amazing how many really need the HPF's in the 35-50Hz range to keep form exceeding Xmax at even moderate power levels. 45Hz will almoat certainly extend driver life by a lot. Link to comment Share on other sites More sharing options...
Members tomhole Posted August 15, 2004 Members Share Posted August 15, 2004 agedhorse, I am using the 30 Hz HPF that is built into the RMX amps for the subs. Should I run an additional HPF on the 01v96's DSP? The reason I ask is I am using active tops (Yorkie EF500Ps') that have a built in HPF selectable for 50 Hz or 100Hz. When I use them with subs, I engage the HPF for 100 Hz and cross the subs to match. The input I got from another 01v96 user was to not use a HPF on the V96 as it might introduce some undesirable phase effects due to the dueling HPF's. So, I used all 4 PEQ's on the mains output to eq the mains and drop the 31 band eq I was using on them. The real reason I am asking is that I tried it with the V and my mains/subs setup. The subs sounded best overall with the 30 Hz HPF on the RMX engaged and no HPF on the 01v set. I did set a LPF at 100 Hz to match the tops (along with 14ms delay for time alignment). I also tried a 21 Hz HPF on the v and that sounded fine as well, so I left it in. It did not sound as tight if I moved the v's HPF up above 28 Hz or so. Tom Link to comment Share on other sites More sharing options...
Members agedhorse Posted August 16, 2004 Members Share Posted August 16, 2004 Were you using both HPF's together? The -3dB point will shift up with both filters engaged. 30Hz should be fine, just be wary of excessive bass boost on the kick. The RMX is a 12dB/octave filter if I remember correctly, what you might try is not using the filter on the RMX and use a 24dB/octave on the 01V at around 35Hz. That may help even more, just remember that if you loan the subs out. 14mSec delay.. which did you delay and how did you arrive at that figure. It seems pretty high between subs and the top box unless you are sticking one way out in front of the other. Link to comment Share on other sites More sharing options...
Members tomhole Posted August 16, 2004 Members Share Posted August 16, 2004 Hadn't thought of disabling the HPF on the RMX. A good idea. The filter on the 01v96 is 18 dB / octave, so that should work nicely. Gives me full control in the digital world and at FOH. The delay is an interesting beast in the digital world. The analog delay between the tops and the horn loaded 1208's is about 8 ms or so. But the digital world introduces some latency between the main outs and the aux 8 out (sub input) at the board. A nice fellow on the 01v96 group measured the delay between the main outs and aux 8 out and came up with 5.6 ms (the subs are slower than the mains. If it were the other way round, I would need to decrease the overall delay. In this case, the output of the aux 8 at the board lags the output of the mains at the board by 5.6ms). I added that to 9ms for the subs to mains physical alignment. I was able to verify that by running a 100 Hz sine wave through the system (built into the 01v and then adjust the delay. When the amplitude peaked, that's the setting. I meant to reverse the phase of the subs and listen for the min volume, but didn't get around to it. Now that's just for 100 Hz. I need to try it again at 60 Hz and 30 Hz and see what the difference is. Should be close, but I would expect a slight difference. I'll take the average of the three and use that for the mains delay. One thing I have learned from SMAART: take care of the time domain before you jump into the amplitude domain. Makes life a lot easier. Tom Link to comment Share on other sites More sharing options...
Members agedhorse Posted August 16, 2004 Members Share Posted August 16, 2004 You should verify your measurements without the filtering (x-over) to be sure that you aren't measuring fringe of the passband phase shift which can be asymetrical. I haven't done this with a digital console and filter code can or can not generate phase shift along with the amplitude change. On analog filters it's all in the math, but at 100 Hz with a 100Hz xover point, you will be well into the phase shift portion of the filter's phase response. That must be one heck of a long horn... 8 feet length? The latency difference between the aux and main outs is unbelievable. To me, that immediately makes the board unfriendly. If you need to worry about things like that then it's too much bother. Do the latency numbers change depending on what processing blocks you have inserted? This is one obvious benefit to a good analog board. Link to comment Share on other sites More sharing options...
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