I got rid of my sub....GOOD RIDDANCE!!

Discussion in 'Archived Threads 2001-2004' started by Miles Abbey, Jun 20, 2002.

  1. Miles Abbey

    Miles Abbey Agent

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    I recently upgraded my boston acoustics vr940 to vrm-90's. I continued to use a boston pv800 with my vrm-90s. Last night, for fun, I unhooked my sub and ran my mains as large. All I can say is the vrm-90s sound so much richer and more musical!! Perhaps I didn't have my sub calibrated correctly, but who cares. It's gone. I may eventually add another sub down the road, but I'm not missing it at the moment. The vrm-90's play down to 33 Hz. What do you audio experts make of this? Why could this be? Is it my imagination. I mean everything sounds good now. Before, only select songs would shine. Does this mean I'm an audiophile? Ha Ha.
     
  2. Vlad D

    Vlad D Screenwriter

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    Miles, give us a more detailed review of the VR-M90's when you get a chance. I looked at the VR-M90's when I bought the VR-M60's. I was really tempted but they would have put me way over budget.
     
  3. Vlad D

    Vlad D Screenwriter

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    Miles, I was just browsing through BA web site when I came across a short review of the VR-M90 by none other than: Miles Abbey - Arkansas City , KS. [​IMG] Just thought you'd like to know.
     
  4. Mike Matheson

    Mike Matheson Second Unit

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    Miles,
    Blending a sub well with the mains isn't always an easy task (in fact, maybe it rarely is). The response curve of some subs can be difficult to work with, many receivers don't offer all that much flexibility for crossovers, etc. There can be lots of reasons.
    It helps to run a frequency analysis of your mains and sub independently to get a good feel for what they actually output in your room and to then use those charts as a basis for beginning to adjust crossovers and slopes and such. Sound messy? Tedious? Yup. [​IMG] Sometimes folks do get lucky though just playing around with settings.
    I'm not familiar with the sub you mention, but I would be inclined to use a good sub myself for HT purposes, even with your current mains--it would free up your mains and your amp from the extreme low-frequency stuff, providing some relief to both your amp and your speakers. A sub could reasonably offer further extension (down to 20 Hz or below) and perhaps better impact and sound. That benefit would only be realized however with an appropriate crossover setup, placement, etc.
    Sounds like you're happy with your system though. So maybe you could just keep the possibility of a sub on the back burner, not show it the light of day until upgrade-itis hits or you hear a different system that seems to imply there might be some low frequency stuff that you're missing (if that day ever comes).
    Regards,
    Mike
     
  5. Michael Lomker

    Michael Lomker Stunt Coordinator

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    I definately wouldn't run the sub with music if you have good tower speakers for your mains. I have the PSB Silveri's and music is far superior without the sub.

    There is something to be said for having a sub for HT and television, though. I think you lose a lot without one. I play mine at a lower level than you're supposed to because I don't like the way most films overpower the other speakers with the LFE content.
     
  6. Martice

    Martice Screenwriter

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    The bigger the room, the more you'll need a sub. If you have a large room and you play music with very low bass information then you'll more than likely need a sub if you like to crank it. You can never have to much sub and I've come to know that calibration, postitioning and room size are major contributors to how your mains and sub mix together. Equalization could be the difference between preferences as well.
     
  7. Greg_R

    Greg_R Screenwriter

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  8. Miles Abbey

    Miles Abbey Agent

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    I agree that music can sound better with a sub. I already sold my sub, but I may someday get the bug to replace it. Next time I will seek professional advice when setting it up. I didn't realize it could be so complicated. Also, I was running the mains as small with the sub so no cancellations. Boston Acoustics PV800 isn't a cheap/low quality sub is it?
     
  9. Dustin B

    Dustin B Producer

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    By commercial sub standards it's not bad at all. But 90% of commercial subs make a lot of size and cost tradeoffs to keep shipping costs and manufacturing costs down. These trade off really hurt performance. No one has figured a way around Hoffman's Iron Law yet.

    The PV800 is around a 50-55L enclosure (hard to make a sub this small play deep and loud without a lot of power). Should weigh more than 40lbs if constructed as solidly as a sub should be (minimum 3/4" mdf with good internal bracing). Having that little volume and two ports I would almost bet money its' tuning frequency is above 30hz (unless the ports are really narrow which is a problem in itself).
     
  10. Earl Simpson

    Earl Simpson Supporting Actor

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    I agree that the rcvr crossover is a problem area. 40 or 50 htz would be nice. But 80htz is ok for theater only IMO.I have set my crossover on the sub at 75 htz and the rcvr at 80 htz and fronts to large. This has helped a great deal on the too much bass at the mid bass range.I have also moved some speakers around and have all the others set to small except the fronts and center. I think I can turn the sub up a notch at this time.
     
  11. Dustin B

    Dustin B Producer

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    I disagree. A good sub properly placed and calibrated can completely disappear into a room with even a 90hz crossover. Problem is very few people take the time to properly place and calibrate a sub.
     
  12. Martice

    Martice Screenwriter

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  13. Dustin B

    Dustin B Producer

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  14. Phil A

    Phil A Producer
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    Bass frequencies sum so that unless your sub is crossed over below where your mains drop off it will produce a bass boost. Different rooms will naturally yield different results. For HT, one is dealing with the ".1" and of course you want those bass effects. For music you want to cross the sub over at a point where your mains don't produce the bass and if the sub is crossed over above where you mains are producing bass in your room then you have a boom box-like sound that does not sound like real instruments. Many people who set up subs for HT, calibrate them for HT use and they may sound great in the HT mode. A SPL and a test tone disc of bass frequencies would be a rough type of estimation as to what is being produced by the mains. An RTA with a calibrated microphone would be better. When I adjust stuff in my own systems or someone elses, I used a one-third octave RTA. Bass is also not consistent at every position in the listening room so measurements are best taken from the listening chair.
     
  15. Dustin B

    Dustin B Producer

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    Phil, I'm really not following you.

    If you set all your speakers to small, and sub to yes every processor I know of will implement a high and low pass filter on the signals that would go to each of your speakers. The signals that come out of the high pass filters will get sent to the speakers and the signals that come out of the low pass filters will be summed and sent to the sub.

    The point of the crossover is to cause the speakers to drop off so that they and the sub sum back to a flat response.

    The exception to this are speakers like M&K. They start to roll off right around 80hz at 12dB per octave. Then they recommend the use of another 12dB per octave high pass filter on them resulting in an effective 24dB per octave high pass filter on the speakers. The sub I believe gets a 24dB per octave low pass filter so that the system sums properly.

    But if you don't have a system designed for this, you don't want the speakers rolling off above where you cross them over to the sub. You want the crossover doing the rolling off.
     
  16. Phil A

    Phil A Producer
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    Dustin, some processors roll off the upper end of the sub differently either fixed or adjustable and also at whatever slope is in the specs (e.g. 12db/octave). This may or may not be optimal for someone's set-up. Also, as noted above above, bass frequencies sum. If you are setting both the exchange crossovers at 90HZ, they are summing and you will get a bass bump in the low 90s-100range area. It is possible that a room response could compensative for this but the majority of rooms exhibit problems around this range (that is why they make bass traps) so it is more than likely in most rooms that you are making a problem even worse. If your mains start rolling off at 90HZ you would want to likely start the roll-off of the sub in the low to mid 80s depending on the room and processor factors. Also when you are going through the digital processing of your processor, you are dealing with its positive and negative qualities. The reason many people like things with outside flexible crossovers (e.g. Rel subs, Outlaw ICBM) is that it allows you to match the characteristics of your system in your room. Also the original person who posted no longer has mono bass (especially if it is as high as 90HZ) and while they are less directional than other frequencies, I would challenge anyone to put your sub behind your listening position and still claim that they are non-directional. I have a bedroom system with one sub and a main system with subs that function as a stereo pair and have set-up dozens of different systems. I am also of the opinion that 90HZ hardly would be a good choice especially with speakers that can go to the low 30s as apparently Miles' speakers are able to go down too. Miles, you could have kept the sub for music if it was flexible enough via the crossover built in to take a signal from your amp and fill-in the bass below where your mains drop-off. That is why a Rel sub has 2 volume controls built in for high level and low level inputs. You set the low level volume and use your processor crossover and then you turn off the DSP (and all the associated circuitry it puts the signal throught) when you listen to music and you set the high level crossover and volume to match your main speakers and room. It connects to your amp to a Neutrik Speakon connector in the Rel to take that amp signal and see the same signal that your mains see but only play the bass your mains are not playing. Many subs will of course for HT only use have more output than a Rel at a lower cost so i really depends on how important music is vs. HT and budget. Also many subs will only have a minimum setting at something such as 35Hz (and perhaps a maximum. This may be good to use a high level crossover to speakers that won't play that low. Also if one can't turn off the DSP the high level crossover is obviously not of great value and if your sub has a crossover you of course want to place the crossover at a point higher than what your processor is doing otherwise you are cutting off some of the bass frequencies except if one has something like a Rel with both inputs and volume controls.
     
  17. Dustin B

    Dustin B Producer

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    So essentially what you are saying is most processors don't do their crossover and bass redirection properly and to get it right for well integrated critical music listening you have to use external passive crossovers that let you control where the high pass and low pass start as well as what their slope is.

    My assumption was that a processor, even the lower end stuff would have it's high and low pass filters setup so that the two would sum flat. In other words an 80 or 90hz crossover would have the high pass start its' attenuation above 80 or 90hz and the low pass start its' attenuation below 80 or 90hz so that they would sum flat. Is this not the case? I know most plate amps have a fixed high pass that is up around 120hz and a variable low pass. Is it the same for most processors?

     
  18. Phil A

    Phil A Producer
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    If you are using the low level connection from the sub out to the sub you are getting whatever is built into the processor (e.g. high and low pass filters at 80HZ at 12db/octave) and your mains are running into that as well as your sub. That is why many quality products allow an analog direct setting. The Sony 444ES in my bedroom system sets the std. at 120HZ for the front, rears or center and is adjustable in 10 HZ increments (when you set the speakers to small) from 40-200HZ and the LFE high cut is 120 HZ std. and you can adjust it for the same range of frequencies and they don't mention the slopes. I have 3 identical speakers in the bedroom and that don't produce the last octave of bass well and when I watch movies the crossover is set to 50HZ. It sounds quite good. When I listen to music I disconnect the RCA to the sub and have wires attached from the postive and negative of one channel of the amp and the postive of the other channel and I put them in the high level input and move the sub crossover to its minium setting around 30-35HZ. There is no comparison listening to music via an analog direct mode with the sub hooked in this fashion vs. going through the DSP in the receiver no matter what I set the crossover modes at. You of course msut be careful and not let the wires at the sub end touch when the RCA connection is in use (short). I moved the Rel Strata III out of the bedroom to use on the rears of my main system and have a Sunfire, Jr. in the bedroom system at present. My friend who works part time at a high-end shop does not even like Sunfire products (that is being kind) and he could not believe the differences. It was like going from a $200 receiver music wise to something much more expensive. The DSP used in most receivers and processors are not ideal for music reproduction and are home theater products and optimized for that purpose. The room of course is the most over looked factor and I can't say enough about either using natural decoration or acoustical treatment, expecially for bass or to tame reflections. My main system has 4 different bass treatments and other things for sound, both decorative and specifically designed for sound treatment. I've helped deliver systems where my friend tried to talk the customer out of certain speakers due to the room they were going in and you can't believe how bad an expensive pair of audiophile speakers and electronics sounded. People want what they want and do things as they wish whether it be high-end audio or HT, sometimes regardless of cost or without even listening to it. Just a couple weeks back, I helped him deliver among other things $20k/pair list Levinson 33H Monoblocks (220 lbs. each shipping weight) and a Levison refernce preamp ($15k list) that were purchased by the customer without even listening to them. While they certainly did not sound horrible by any means if I was to spend that amount of money I'd want to hear them and do something with the room. He had a Rel Stadium sub ($4k?) that was hooked-up inadequately and he had no idea how to start that I fixed for him to match his B&W signatures ($12k list), a VPI (TNT MK-V Hot Rod) $8k list turntable and that cheap $2.7k Marantz SA-14 2-channel reference CD/SACD player with some expensive interconnects including stuff like $1,800 Transparent reference just between the preamp and CD player. That is not even close to the most expensive system I've seen as I've seen one that was over $140k 2-channel only that had things connected in it that could not possible make the sound better (e.g. line conditioners on thos same Levinsion monoblock amps which already have line conditioning it them and they tell you that if you read the big manuals they give you. And I've even seen more expensive that that. If you something tht is good for HT, it is not necessarily going to be the ideal for music reproduction. Try measuring your room (an SPL meter is not that expensive from Radio Shack and a test disc such as "Surround Sound Spectacular" on the Delos label is about $18 at CD Now and includes one disc of music in surround and one disc of tests, including bass tones. I suspect that is why Miles was happy to get rid of his sub. If there is no means of turning off a DSP, the result may not be best for music. I do the same thing when I listen to my main system. I turn off all the DSP and use the speaker (high) level crossovers in my Rel Storm IIIs up front to compliment the bass of my mains. My old AVP processor/preamp I recently sold was not at all terrible playing music and with its adjustable crossover points was nice for HT but not the ideal for music and it was better than most things out there in the DSP section. A HT set-up can be very convenient with everything in one box and calibrated for surround sound. It however, is a different animal from those pieces designed for music reproduction, although bypassing he DSP and being able to match a sub to the mains is going to get one closer at a lot less money (and weight).
     
  19. Dustin B

    Dustin B Producer

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    I've got Avia and a Ratshack meter. I'm well aware I have some major room response problems around 40hz and 140hz or so. But I currently don't have the means to try and solve them.

    When I move, which will hopefully be in the not too distant future, getting the room interactions tamed will be up there on my priority list.
     
  20. Mark Tranchant

    Mark Tranchant Stunt Coordinator

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    Phil A: aargh! Use paragraphs, please!! Your posts contains lots of useful information but are so hard to read as a single block of text. [​IMG]
     

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