Adjusting Crossover.

Dustin Stock Silver Member Username: W00b Post Number: 255 Registered: Mar-05	Posted on Thursday, September 24, 2009 - 04:40 GMT I have a digital crossover and I'm wanting to adjust it to split my speakers and subwoofer apart. What is a good way to go about testing? I was thinking about playing test tones and seeing the lowest point that my speakers will respond to, and use that as a crossover point to my subwoofer. Is this an efficient approach or should I do something differently? thanks
Nuck Platinum Member Username: Nuck Post Number: 13535 Registered: Dec-04	Posted on Thursday, September 24, 2009 - 11:48 GMT DS, if I understand correctly, you are making your speakers into crossoverless units and going active? If so, begin with the factory crossover points and use matching amplifiers first.
Dustin Stock Silver Member Username: W00b Post Number: 258 Registered: Mar-05	Posted on Thursday, September 24, 2009 - 13:53 GMT i have one amp for a subwoofer and another for my speakers. my speakers have 12 inch woofers on them, but i'm going to limit the frequencies being sent to the speaker amp with the digital crossover, and the rest of the lower frequencies will be sent to the subwoofer this is obviously to prevent huge peaks in frequency response because the woofers i have can go decently low aswell.
Jan Vigne Platinum Member Username: Jan_b_vigne Dallas, TX Post Number: 13930 Registered: May-04	Posted on Thursday, September 24, 2009 - 14:37 GMT . "this is obviously to prevent huge peaks in frequency response because the woofers i have can go decently low aswell." First, realize that peaks and dips in frequency response result from the speaker/subwoofer interaction with the room and your placement within the room. The room itself (it's dimensions and overall shape) determines where and how severe the response variations are and all you can do is work with the room you've chosen. Yes, if you turn up the amplitude of the signal at the point where both speaker systems meet, you will introduce a lump in the room response, but your plan might need more thinking before you achieve the desired result. Placement of the speakers/sub/listening chair will begin to tame room response. Acoustic treatments then step in to even out the room response. EQ is typically ineffective unless it can be very refined in its action which is nowdays the job of some fairly sophisticated systems. Test tones are unlikely you tell you much about how and where to set your crossovers unless you tend to listen to lots of test tones rather than music. Dustin, I have the feeling you're trying to assemble a Frankenstein system of disparate parts and hoping for good results. Let's make sure of one thing, we are discussing home systems, right? This is not a car stereo question, is it? If so, give us more information on the components you're trying to work with. 12" woofers mean little as far as frequency response and I am unfamiliar with most "digital" crossovers that can actually become useful in the situation you intend. Normally, if you tell me the main speakers "go decently low" I'd ask why you're adding a sub in the first place. So, just what are these speakers? Is this for home theater applications or music? What is "decently low"? Is that actually measured response or manufacturer's spec? How much lower response do you expect to get from this system? Does the music you listen to warrant that sort of deep bass response? For the sake of discussion, do you know about where the lowest frequency would fall in the typical music you listen to? Is this from bass guitar, synthesizer, piano or some other instrument? Is there some other reason you are trying to get such deep bass response? Have you tried different placement of the sub? Why this set up and not a more conventional powered sub with a plate amp and crossover? What are the options you have available on the crossover? What is the lowest and highest frequency knee for both high and low pass filters? What is the filter type, first order (6dB)? Second? Fourth (24dB)? Is that adjustable or fixed? What have you done with room and speaker set up? Is this your first attempt at taming peaks? I notice you also posted a question about an older Akai receiver and some Behringer gear and how to hobble together that system. But you didn't at that time have the sub or the crossover and were unsure how to make everything work together. Is that the system we're discussing here? Have you purchased the sub and crossover? If so, what are your goals for this system? I can't imagine there would be anyone on this forum that wouldn't advise you to pay attention to the front of the systyem before you began pouring money and effort into the lowest octave of bass response from this system. What is it you're trying to do with this system? "Heres my situation. I have a very old stereo reciever. It's an AKAI AM-A70. It is hooked to an AKAI EA-A2 equalizer. I have an RCA Y splitter running from my PC, to the EQ, the signal gets EQ'd and passed to the reciever. So that works fine. But i'm going to add a subwoofer. Problem number one. No subwoofer output, no output what-so-ever on the reciever. Solution number one: For whatever reason, the EQ has 2 simultaneous outputs on it. I have tested both running at the same time. Now here's where it gets tricky. Problem number two. No crossover from the EQ to the subwoofer's amplifier." Dustin, it sounds to me like you're coming here from car stereo and thinking all that BS the car stereo guys piece together works just the same for home systems. If so, the first piece of advice I'd give to someone in that situation is to forget everything you thought you knew about audio that came from the car stereo market. .
Nuck Platinum Member Username: Nuck Post Number: 13538 Registered: Dec-04	Posted on Thursday, September 24, 2009 - 15:04 GMT This might be very interesting and informative, I hope this thread goes places for Dustin and others.
Dustin Stock Silver Member Username: W00b Post Number: 259 Registered: Mar-05	Posted on Thursday, September 24, 2009 - 19:00 GMT I appreciate your post jan, you ask very good questions. I willl try to answer them as best as possible. 1) Let's make sure of one thing, we are discussing home systems, right? This is not a car stereo question, is it? Definitely not. I was considering purchasing a car audio system but decided not to. I do post on the car audio forums occasionally. 2) If so, give us more information on the components you're trying to work with. I have a pair of AKAI speakers that also came with the receiver. On the speakers shows a performance graph showing a slope that hits 0db at a little passed 50hz. The AKAI speakers are 3-way and remind me of a pair of cerwin vega speakers that someone else posted a picture of on this forum before. The model number is SR-LA301 for the speakers. 3) Is this for home theater applications or music? This will definitely be for music. I watch movies too but I do so using full dynamic range compression and the audio is converted into L/R stereo through computer software. (AC3Filter) anyways. 4) What is "decently low"? Is that actually measured response or manufacturer's spec? I find the graph to be relatively accurate. Below 50hz I can see the output gradually diminishes and my woofers don't move as much at the same volume levels. 5) How much lower response do you expect to get from this system? There are many times when listening that I can tell a hint of a lower frequency that my woofers are just barely responding too. It is commonly followed by a different 'note' that my woofers respond fully too. It's things like this that make me want a subwoofer to fill in a fuller range. 6) Does the music you listen to warrant that sort of deep bass response? Im one of those 'everything but country music' people. I'm sure theres a billion of me these days. My taste is somewhat universal but I have certain things that I don't like. I would say I listen to hip-hop and electronic music the most, but I listen to music almost all day while i'm not at work. 7) Have you tried different placement of the sub? This is more of a pre-installation question. I am having a very nice sealed box being built for my subwoofer. I want to be ready for some of the problems that I may face, as I know that I still have a long road ahead of me. It's never bad to have some plans ready though, right? 8) Why this set up and not a more conventional powered sub with a plate amp and crossover? I considered this approach. I decided against it because i wanted the amplifier and subwoofer to be seperate, in case i changed plans in the future. As far as the crossover goes, I guess it might have been a better solution for that. 9) What are the options you have available on the crossover? my crossover has a ton of features really. '(Butterworth, Bessel and Linkwitz-Riley) with selectable roll-off characteristics from 6 to 48 dB/octave. The delays for all inputs and outputs are adjustable. This allows you to manually or automatically correct for room temperature, phase and arrival time differences.' 10) What have you done with room and speaker set up? Right now, I have a bit of a weird setup. from the corner of my wall, it goes <speaker><center><speaker>. My Computer Desk is located to the right of this setup. As you can tell, I'm not much for soundstaging. I will probably place the sub under my desk, against the wall. I will just have to experiment with that. I need to move the TV out of this room if i want to arrange my setup differently, and I will if i need to. 11) Is this your first attempt at taming peaks? yes, this is my first time ever working with a crossover and taming peaks and things like that. I am a pretty quick learner and especially if its for my system here I won't give up until i figure out something that works. 12) Is that the system we're discussing here? Have you purchased the sub and crossover? the sub is here and the crossover is shipping. The box is being built for the sub as i mentioned earlier. 13) If so, what are your goals for this system? My goal is to add a subwoofer to this otherwise dated, but good system. If my idea fails then I will indeed go with a plate amplifier and have that mounted into my subwoofer enclosure. I may or may not have made the best choices according to some people.. but try, fail, and try again. 14) Dustin, it sounds to me like you're coming here from car stereo and thinking all that BS the car stereo guys piece together works just the same for home systems. I understand your concern. It's possible that there are a billion things I don't understand about home audio. Perhaps, that is why I'm here. However, no matter how it looks, I have been planning since the day I signed up to ecoustics to add a subwoofer to this same system. I have done a lot of research, asked a lot of questions, maybe not the right ones. There may be just as many things that I haven't thought out, but I know I have done a lot of planning, at least on the technical side of things. I look up to people like you, Jan, who seem to always know what they are talking about. It's not just about adding a subwoofer really, it's also kind of about trying something new. Something that might be against the 'norm' but still works. Even if my first attempt isn't the most satisfactory from an outsider looking in, I will be satisfied knowing that I have made a good effort to accomplish my goals. And honestly, I couldn't have done it without places like this, where people share just as much or bigger passions for audio.
Nuck Platinum Member Username: Nuck Post Number: 13543 Registered: Dec-04	Posted on Thursday, September 24, 2009 - 20:48 GMT DS, I doubt that I have ever read a more well written and concise response, with the requesite humour that you have on hand. I need to review the post again to see where you are headed and what you want to achieve. With your musical happiness in mind, where do you see your music listening place to be? What do you want to hear? What systems have you heard, and do you value synergy over tuning? Do you belive that you have reasonably maximized your listening space? Welcome, again.
Jan Vigne Platinum Member Username: Jan_b_vigne Dallas, TX Post Number: 13931 Registered: May-04	Posted on Thursday, September 24, 2009 - 21:29 GMT . "13) If so, what are your goals for this system? My goal is to add a subwoofer to this otherwise dated, but good system. If my idea fails then I will indeed go with a plate amplifier and have that mounted into my subwoofer enclosure." Give me more information, "I want to add a subwoofer" is not really a goal, its an action - or more specifically, it's a purchase. Purchases are not goals. Goals are more in the vein of, why a subwoofer? What do you expect to get from the sub that isn't there now? What do you expect from the system once the sub is in place? Just "bass"? I understand you expect bass but, why a sub? What driver did you buy and where are you aiming the resonance of the system with the enclosure? What amp is going to run this subwoofer if you're basing the whole system on an Akai receiver? You're not still planning on using the Akai eq, are you? Why a sub? Particularly a sub where the crossover probably costs as much as the receiver did new. You say you're not much on soundstage, so, what are you "much on"? What does the current system do well and what does it do poorly? How does that relate to adding a subwoofer? Sorry to keep on about this but a subwoofer seems to be heading this system in a specific direction that I don't think most forum members would say is where they would spend their money of this were their system. .
Nuck Platinum Member Username: Nuck Post Number: 13545 Registered: Dec-04	Posted on Thursday, September 24, 2009 - 21:39 GMT having the sub in an active setup is complimentay, and also opens up more active xo's to play with, depending on which Behringer is employeed. While hardly esoteric, the Begringer units offer active, balanced and reasonably priced options for active setups. A very good starting point for several reasons.
Dustin Stock Silver Member Username: W00b Post Number: 261 Registered: Mar-05	Posted on Thursday, September 24, 2009 - 23:09 GMT Yeah, a lot of people recommend the behringer amps. Jan, just when I thought you couldn't ask better questions! okay! 1) Goals are more in the vein of, why a subwoofer? What do you expect to get from the sub that isn't there now? What do you expect from the system once the sub is in place? I would say that I want a subwoofer to add some detail on the low end of the system. I'm not a basshead by any means. The music I listen to sometimes requires good low end extension to get the 'full' experience. I want to be able to listen to my music more towards the way it was meant to be heard. It all comes down to the fact that my speakers just don't reproduce some of that lower end. Other than that, I honestly have no complaints about my system. I have hooked these speakers up to a few different recievers and the way that it colors the signal is very unique to me. Listening to hip-hop or electronic music without a subwoofer is kind of like watching the workprint of a movie. You get the point, but some details just kind of aren't there. The producer intended for more to be there. I want to move in the direction of what the producer heard when he had the song in mind. Hopefully I am making sense. 2) You say you're not much on soundstage, so, what are you "much on"? I was referring to the fact that my speakers aren't in a position where I pay much attention to the soundstage. Both are on my left hand side. I enjoy doing work on the computer and listening to some tunes while I'm browsing the web or, whatever it may be. Which brings me to your next question! 3) What does the current system do well and what does it do poorly? How does that relate to adding a subwoofer? What I like about my system is that no matter what I listen to, everything seems well balanced. When I say well balanced I mean that, the highs give clarity, the lows are tight and responsive, never too boomy. The mids are never overpowering. Vocals stay in the middle of the music, and never come out more than they should. I normally don't listen very loudly, but I find that the more I turn it up, the more I enjoy it. I can feel the 'energy' of the music. Of course, when a really low note hits, that exposes my systems weakness. It just doesn't sound right, you can tell that my system is trying to play that note, but that is the only time that I can see my systems limitations. So you see, I want to fill that void, and give my system that range that it wants to play. and give my ears what they have been missing. I hope I'm not confusing you guys! 4) What driver did you buy and where are you aiming the resonance of the system with the enclosure? What amp is going to run this subwoofer if you're basing the whole system on an Akai receiver? I bought a Dayton RSS315HF-4 subwoofer. I have not seen a single bad review of this subwoofer, and it is a relatively cheap driver. People say it is quite a musical driver but can also double for home theater applications. The driver will most likely be aimed at my chair, since it will be under my desk. It's going to be outward firing, I don't see a downward firing driver doing me any good in a carpeted room. Maybe there's something I don't understand there aswell? I hope i'm answering your questions with the detail and clarity that you are wanting Jan! Sometimes I can be a little unclear and I apollogize. I guess some people may not make the same choices I would make if they were in my situation. I guess my only question is... WWJD? what would you do, Jan?
Nuck Platinum Member Username: Nuck Post Number: 13548 Registered: Dec-04	Posted on Thursday, September 24, 2009 - 23:21 GMT DS, your choice of paths makes sense for 2 reasons. Firstly, the choice to go active with the bass. The addition af an active XO, and the attendant removal of the existing passive XO, will grant you stress relief for the somewht suspect power supply that you are using now. Secondly, the addition of a seperate power supply and XO will let you integrate the bass into your room much more naturally, whicj is difficult sometimes.
Nuck Platinum Member Username: Nuck Post Number: 13549 Registered: Dec-04	Posted on Thursday, September 24, 2009 - 23:27 GMT However, if the XO is using a small order XO (below 24 db/Linkwitz) you will have a problem in the frequency roll of the unit, no matter what. A proper 4th order crossover may expose the driver, but will not let a full octave of rolloff tarnish your impressions nearly so much as a primay or secondary would.
Dustin Stock Silver Member Username: W00b Post Number: 262 Registered: Mar-05	Posted on Thursday, September 24, 2009 - 23:41 GMT Thanks nuck, If I understand you correctly then I may be clear of this problem. My crossover goes from 6db up to 48db/octave and offers 3 different crossover types. linkwitz is one of them, there is also butterworth and bessel. I don't know what any of these terms specifically mean, I will have to experiment with them. the crossover also has a parametric equalizer for all of its outputs.
Nuck Platinum Member Username: Nuck Post Number: 13552 Registered: Dec-04	Posted on Friday, September 25, 2009 - 01:59 GMT OK then I suggest that your use the 4th order, crossover at the factory settings, remove the bass XO(coil) from the existing speakers altogether and apply the amplifier of your choice. If I have misjudged the setup, I blame the King of beers.
Jan Vigne Platinum Member Username: Jan_b_vigne Dallas, TX Post Number: 13933 Registered: May-04	Posted on Friday, September 25, 2009 - 16:25 GMT . It hardly matters what I would do, I'm not you and my experiences and decisions have been quite different from your own. I can't see myself spending the money for this sort of subwoofer arrangement if that is what you are asking, not given the system that it will partner. However, my priorities would appear to be quite unlike yours. I disagree with your assessment of hip-hop and most electronic music, they do not require deep bass response. The energy of most genres and these in particular is well within the range of many modern speakers with well designed drivers and enclosures. That energy is peaked at around 60-100Hz and most people simply mistake quantity of bass with extension of bass. This is a common reaction since our preception tells us that louder low frequencies are lower in range when they are not they are just louder. The typical first reaction is due to the Fletcher Munson curves that we all ascribe to by nature (http://search.yahoo.com/search?ei=utf-8&fr=slv8-hptb5&p=fletcher%20munson%20curv e&type=) and has been used by speaker designers to sell many not so great systems. Your description of the system lacking bass detail then would suggest to me - along with some experience with the Akai systems - that what you have is a bit less than a knock off of a Cerwin Vega. The drivers and the enclosure resist the sort of "detail" you are seeking. If you are satisfied the rest of the speaker does what you prefer, then you have yourself some speakers to work with. What I would have suggested is a different pair of speakers that would have cost less than what you have spent on the subwoofer arrangement but would have provided IMO more room for growth and a more immediate improvement overall. Like I said, my priorities don't appear to be in synch with yours. When I asked about where you were aiming the resonance of the subwoofer I was asking not about how you would align the box to your chair but about the enclosure/system resonance cutoff. IOW, how low do you expect this system to go. Sealed boxes have distinct advantages/disadvantages over vented systems in just how deep their extension can reach (due to the more gradual rollout of the system compared to a vented box) but this is at the disadvantage of enclosure volume. Three cubic feet is a pretty big box and the four Ohm load of the Dayton driver will require a substantial amplifier. I'm seeing this all as a rising cost for minimal value at this time. Once again, I would have spent the money on another portion of the system. Given what I suspect will be the benefits of this and weighed against the system itself - the Akai receiver with the eq and the computer source and the patchwork of cables to make this work, I just wouldn't have suggested this route. Sorry to be so "anti" but other than some extension into the midbass and clarity where your present speakers are fighting themself to work I think you've spent a lot that otherwise could have resulted in more benefits. You don't have to consider much about the various filter types offered by the crossover, for your intended purpose most any of the filters will sound pretty much the same. Regarding the parametric eq, I tend to consider this quite a waste in most consumer systems. Without the proper calibration gear you are doing nothing more than adjusting the system to sound as you prefer over a wide range of material or playing with the controls endlessly. Neither approach gets you where I would have suggested you end up. Even with the corrrect set up gear most eq's - even parametrics - tend to do more harm than good IMO. Given that some improvements gained by proper placement are free, I would have explored that route first. Given what I know of the Akia components and speakers I have to disagree that this is a well rounded system. None the less, we are where we are and my ears aren't making the decisions. I don't understand Nuck's instructions about set up. First, since you haven't specified the model of the crossover you've ordered I don't have a clear idea of its capabilities or your real intentions. I'll assume that at least for now you're just going to deal with this as a subwoofer system addition and not allow the crossover to affect the frequency response of the main speakers. Keep your changes simple and only change one thing at any one time. Don't decide you need to do everything this unit can manage just because it can. You'll quickly get lost in what you can do and what you've changed and you won't have the ability to track back to where you thought something sounded better if you make a wrong adjustment. Keep the changes to a minimum and only work with the subwoofer for now. Set the preferred or default filter type and adjust the crossover to the lowest knee frequency the unit allows - if it goes down to 40Hz, set the crossover at 40Hz. Set the filter operation to a broad, gradual rolloff with a first order filter. After you've listened to some music I would then sugegst you change the filter rollout before changing the knee. Try a second order or steeper filter. Once you're satisfied with the filter rollout move to the knee and gradually raise the frequency where the sub takes action. When you think you have this figured out go back and play with the rollout again. Ignore the rest of the controls on this crossover. One problem I see is the innumerable changes the crossover would appear to allow. If you don't know how to use them correctly, they tend to become nothing more than toys that get wiggled around aimlessly. If you don't have the set up gear to make the best of the controls, they become more and more useless IMO. Even under the best of conditions, using controls to make up for deficencies in the system is not my first - or second or third - choice. I have no idea why you would want to remove the bass XO coil from the speakers. I just don't know where Nuck is headed with that advice. DS, this hasn't sounded very promising and for that I can't aplogize. To my way of thinking you're asking me how to salvage a cake that has had more than half the ingredients left out. I honestly don't know how to respond when your approach to this is so wrong headed to what I would always suggest as correct system building. It's your system and your money but I don't have good advice for someone who I think is headed in the wrong direction. You don't have to like what I like and I've told everyone on this forum and all my clients over 25 years of selling audio I don't expect anyone else to like what I prefer. But I don't get your expectations - what you seem to claim as your goals are tight bass and clear mids. There is, as far as I am concerned, much more to this than those two perogatives. What you have pulled into the shop is a car held together with duct tape and wire nuts and you're asking about adding a supercharger and 5.88 gears. I would have told you to rethink this or else put new tires on it and drive it till it stops. Like I said, we are where we are. Good luck. .
Nuck Platinum Member Username: Nuck Post Number: 13565 Registered: Dec-04	Posted on Friday, September 25, 2009 - 17:49 GMT DS introduced the active XO into the mix, and that is not always a bad thing, IMO. I think he got into more info and technicalities than he bargained for.

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