I currently own an Energy 10in sub (ES10) and although it has served me well for over 10 years, it's time for a serious upgrade. Enter the EP500 in the equation, at least that's the plan.
My question is, do any of you see an issue in running both subs in my HT system ? The EP500 and the Energy ? I don't really have another place for my ES10 and I don't really want to sell it either.. I figured with both subs I can better bass integration, like Jakeman with his 2 EP600s AND 2 EP500s kind of idea..
I don't believe "sub matching" is that important in terms of brand / size but I though I would ask to see if anyone has had any issues doing what I am proposing.
Thank you
Cheers,
Steph
I think with proper placement, you might achieve good results. If possible, try opposite walls to help even out frequency response.
Thanks Randy, that's what I was thinking as well, I currently have my sub next to one of the side wall, middle of the wall and it sounds the best there. Up front with my mains is the place it sounds the worse, in my room anyways. So, one on each side of the listening position should really work well I think.
Sure, Stephane, give it a shot. Putting the subs at the midpoints of opposite sidewalls, as suggested in the Harman paper prepared by Dr. Toole and his colleagues, would cancel and/or avoid some of the room resonances, plus giving a 3db boost in loudness.
I was able to integrate my old M&K MX-200 into my M80, EP600 system but it took some doing. Placement was tricky as the room is not exactly acoustically friendly and flipping the phase switch was also needed. However once I found the right spot I wouldn't want to give it up. Unless of coarse it was for another EP600!
I have been wondering about dual subs as well. Practically all of the low bass in a movie soundtrack is recorded into one channel, the LFE. Even if it weren't, low frequencies are mainly non-directional such that only a few people can perceive separate sound sources below 70Hz. Since the EP-500 has a brick-wall cross-over implementation, there is no extension of output above the cross-over, thus making the EP-500 even more difficult to localize (easier to place) in a room. My pre/pro has the capability to run two subs and when all speakers are set to small, the left sub gets the bass from the center, left main ,and left surrounds, and the right sub gets the center, right main and right surrounds (in addition to LFE for both subs of course). While this bass distrubution is stereo, as compared with the LFE channel, inability of our ears to localize this low bass still applies. So, if one EP-500 is sufficient for a given size room, why would there be a benefit to using two subs? I would really like to hear others' thoughts (especially those of Jakeman and dllewel) on running two or more subs.
John
Quote:
Sure, Stephane, give it a shot. Putting the subs at the midpoints of opposite sidewalls, as suggested in the Harman paper prepared by Dr. Toole and his colleagues, would cancel and/or avoid some of the room resonances, plus giving a 3db boost in loudness.
Right on. Just a small clarification, a pair of colocated subs add 6db of extra output due to mutual reinforcement. As you place the subs more than 2 metres away from each other the output from coupling diminishes at certain low frequencies but you should get more than 3db unless you have a very large room. The actual amount of extra output outside of the 2 metre boundary will be between 3 and 6db. If you add a third sub ideal mutual coupling will give another 3db for up to 9db in "free" output and a fourth sub ideally placed will give to 12db. I use a colocated test to make sure each sub is functioning properly, ie not wired out of phase or outputting less than spec. In my room with 3 subs I get about 7-8 db more combined output which means I need to level each sub to 65db.
John
Here is one of the Harman white papers by Todd Welti that deals with why multiple subwoofers are necessary in a HT application. It solves several problems such as getting more output and accordingly lowering distortion, smoothing room nodes and obtaining flat frequency response in many seats not just the single sweet seat where you like to sit. The more subs you add the less problems with room nodes across more seats and the better low bass detail and articulation.
A couple of years ago I was watching an episode of 24 with my two sons and I was enjoying the LFE in my sweet spot. One of my teenagers sitting 3 feet to my left started to complain of very loud bass drowning out the voices. My other son 3ft to my right thought son#1 was just causing trouble and said he hardly heard any bass. Multiple subs to the rescue.
http://www.audiovideointeriors.com/images/archivesart/0106toolemultsubs.pdfYour question about stereo subs are another matter and from the way you describe your processor I doubt you can get stereo subs with a dolby track since mono LFE and mono centre is being redirected to both subs. The only processor that I know that allows for stereo subs and a separated LFE only output is the Lexicon MC12.
Anytime I have experimented with stereo subs I have split the L main channel signal to one sub and the R to the other. I set the processor to no subwoofer to avoid sending the same mono redirected bass to each stereo sub. I then run a dedicated line directly from the dvd player to the sub. Overall its more trouble than its worth IMO since it creates tricky phase issues between the individual subs and speakers. In addition you need to also adjust the LFE loudness separately at the sub.
If you want stereo bass effects and your processor permits separate speaker bass management, a better way to go would be to cross full range speakers like the M80 at 40hz and run a pair of mono EP500s .
>>Since the EP-500 has a brick-wall cross-over implementation, there is no extension of output above the cross-over, thus making the EP-500 even more difficult to localize (easier to place) in a room.
I thought the brickwall filter was used to cut off extreme low frequencies (10Hz-type stuff), and that the crossover to mains was a conventional 24 db/8va filter. Not 100% sure though...
The EP subs use a brickwall digital high pass filter at 19hz for the 500 and 16hz for the 600 (23hz for the 400 ?) and 100hz digital low pass filters. I believe they are may be introducing a firmware update to increase the low pass to 120hz which will be helpful with blending monitors. When you set the crossover you are relying on the 24db (or in some cases a 12db sloping filter) in the processor which works "normally" as long as its in the band of the subs digital brickwalls.
John,
Thank you for a great explanation (justification) for using more than one sub. The article is fairly short but illustrates that using up to 4 subs can minimize variation of FR from one location to the next within the seating area and helps to minimize the variation of overall FR within the seating area. By the way, the study is on only one low frequency audio channel sent to all the subs. They mention that there is "questionable" advantage to having stereo or more bass channels/subs. My processor does not create a stereo LFE output to two subs, but it has the capability to redirect bass from the left main and left rear channels into a left subwoofer and redirect bass from the right main and right rear channels into a right subwoofer while giving the same LFE signal to both. Since separate bass channels is of questionable benefit, good news is that I can use the same SMS-1 to run 2 EP-500s if needed.
PS: John, in reply to your comment about the only processor that allows for stereo subs and a separated LFE only output being the Lexicon MC12. My processor is identical to MC-12 in this regard with 3 sub outputs, one for LFE, two others for L and R channels for redirected bass +/- LFE. In essence, I don't have to set the low-pass to 40Hz to hear more stereo bass from the mains since the 2 sub channels in the processor can run two subs in stereo.
John
Nice processor, John,
. I thought only the Lex had that feature. Which one do you have?
John, it is the Yamaha DSP-A1, now several years old but still running strong. It has 3 subwoofer outs (2 for stereo subs and 1 for mono) with custom bass management options for LFE and redirected bass for all 3. In addition, the subwoofer output levels for DD and DTS can be set individually, meaning that when DD signals are being processed, the LFE out can be set to have one level, and when DTS signals are being processed, the LFE output can be set to a different level. The two levels are stored and automatically recalled when playing one format or the other. This is potentially useful since DD apparently has an LFE output that is 10 dB above the main signal, as recommended by Dolby. In my case, I decided to keep the same subwoofer level between DD and DTS soundtracks. Despite all of these wonderful features, I think it will soon be time to upgrade.
John
I would think that DTS has the same 10dB boost. The receiver makes the adjustment as the line signal doesn't have the extra 10dB of headroom above the other channels. This is just because LFE effects were designated to be much louder than the other channels. This is just my opinion, as I have not noticed a large difference in LFE volume between the two types of encoded soundtracks.
Dave,
I think the DD spec of 0dB for LFE channel is actually +10dB relative to other channels. For DTS, equivalent setting is +10dB for the LFE. The recorded signal has been attenuated on incoming signal to allow more headroom when large explosions and such take place. Yamaha DSP-A1, Casablanca Theta processor, and perhaps some others that came out around '98 had the ability to set different LFE levels for DD and DTS. I keep DD at 0dB and DTS at +10dB and adjust the LFE from spekaer level menu during calibration, which then automatically adjusts both DD and DTS levels by the same amount. It may not be a bad idea for a processor to be able to adjsut LFE for DTS and DD separately since there is some inconsistency among various music and movie sound tracks; for instance, some have reported that early DTS music tracks require the +10dB setting whereas the later ones require the 0db setting.
John
Yes John, flexibility is always best as there are many variances among source content out there.