To DSP or not?

Honestly, you need to read and learn more here if you plan to go DIY in my opinion. It's not that difficult - but you should understand some of the basics.


To use a DSP you need to know what parametric EQ settings you want to plug into it, otherwise you are shooting blind.


Real world experience follows: I've measured the same four SI drivers in multiple rooms:


With a quad set of SI in scrappydue's room we had to cut boost at the lower range of 15hz-20hz by about 8dB when four were powered by an iNuke DSP 6000 to get a flat response. In my room with four SI I had to boost about 12dB at 15hz-20hz when powered by a CV-5000 to get a flat response. This had nothing to do with the two amps - but about the room and sub's placement within the room. With the same SI four sub setup in carps room he has to boost the SI about 6-8dB in the same range. You'd never know that unless you measured with a frequency response tool like REW, or Omnimic. It's quite possible if you just use the SI subs with no DSP that you'd end up having a very large bump in dB at say 40hz in your room and have a very unwelcome frequency response with no lower end impact. And it's not just the lowest end of the audio spectrum that needs tailoring. Auto EQ tools like Audyssey XT32 will go along way to help flatten your bass response, but they won't always help you with a DIY sub attempt with no other EQ help.


Here you can see what your punch, depth and flat DSP EQ functions were doing on a Klispch RW-12D
http://www.avsforum.com/t/1390563/klipsch-rw-12d-omnimic-frequency-response-graphs




Here's is what a SI driver frequency response looks like without any EQ.

pic compliments of data-bass.com



Take a look at those native frequency response differences. The SI definately needs EQ - just like the Klipsch RW-12D has built in with the factory DSP settings.


If you don't want to learn how to measure your FR, then I would suggest you go with a manufactorer's sub instead of DIY. IMO - you will be more likely to be pleased with your final results.

With all due respect because I see you have a lot of posts here and I am sure you know what you are talking about, I think your answer is rude.


What I am enterpreting is that unless you have fancy mics, fancy programs and a degree is sound engineering you have no business in DIY. I think you are mistaken.


I admit, that I understood about 3%of your paragraph. That is reason we ask these questions here. Not all of us have the experience of having 4 18"subs and being able to test the with the necessary gadgets. I realize that the DSP helps compensate for some of the shortcomings of the room, or the sub enclosures but for someone to state that if I don't understand what a DSP does, I should stay away from DIY, kind of sucks. Because there are plenty of people here that understand much less than me and build some beautiful diy project and eventually learn everything that is needed. That is the reason we newbies come to these forums to ask questions. I had the store bought subs, pretty decent ones too but it was not enough and that is why I went with the DIY route.


I have some decent carpentry skills and can build the cabinet just fine, but need help in the sound portion of it. Some folks here have awesome set up skills and understand the technical aspect of it but can't build a cabinet if their life depended on it, so they ask questions about building the cabinet. It would not be fair for me to say that if you cannot build a cabinet, you should buy a flat pack or just go buy a store bought subwoofer.

All Archaea is saying is; there is a wealth of information available to everyone here. You can gain a ton of knowledge by browsing through numerous posts. At that point, guys are more than willing to answer specific questions.


In a nutshell. Those of us in here are after a smooth bass response at the limits of our system. A good sub in a poor room (or with a poor FR) will sound poor and a poor sub in a properly treated room with a good FR can sound great.


The nice thing with the Nukes is you are spending less overall to get amplification and equalization; than by achieving it some other way. The only complaint I have with the Nukes DSP is the somewhat higher cutoff. There are some workarounds however, that will get you lower.


REW is a great program (oh man I sound like Bee, lol), to help you get the most out of your system. If you don't want to mess around with computer programs; a simple DB meter and some test tones will help you address areas of concern.


Here is a before and during shot when tuning my FR with SMS's. You can see the benefit of a smoother FR as well as ability of implementing a "house curve".

Thanks Bass, I understood what he was saying and the real world experience was a great way to explain that without a program and mic to test your subs you would never have know that there was a problem. With that I understood that once you knew there was a problem, you could adjust the settings on the DSP to compensate and help. Is that correct? Or is the DSP what tests the sub and room to find the problem?


My problem was with his comment "If you don't want to learn how to measure your FR, then I would suggest you go with a manufactorer's sub instead of DIY." Never did I say I didn't want to learn, I asked if someone like me that doesn't know much about it would be better off getting an amp without it so that I wouldn't mess things up.


So back to my original question, would leaving out the dsp in place for more power be recommended or should I stick with an amp with less power and get the dsp so I can help compensate for room and placement?



Quote:
Originally Posted by cessna1466u  /t/1517259/to-dsp-or-not/0_80#post_24343426


With that I understood that once you knew there was a problem, you could adjust the settings on the DSP to compensate and help. Is that correct? Or is the DSP what tests the sub and room to find the problem?

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The DSP is a tool to help you "tailor" the FR to overcome room nodes. You first need to find out what you FR is. REW is a great one but has a steep learning curve. A DB meter and some test tones will get you 90% of the way though.


Something as simple as moving your sub 6" can affect FR. Room treatments, when allowed, are critical in tailoring not only your sub, but your entire audio setup.


Myself, if I had a max budget and this meant either a more powerful amp without DSP, or a less powerful one with it; I'd go for the latter (assuming you wouldn't be buying one down the road). If you can afford one later on then that would need to be taken into consideration.

What I was trying to convey, in a manner I thought was softly, was that you can learn a heck of a lot quick about the basics just by reading through threads. I certainly wasn't trying to deter you, in fact I did say it was not that difficult in my first couple sentances, but that if you weren't interested in learning to capture your frequency response and apply the appropriate DSP settings - you might be disppointed with your first project's outcome. I was not trying to discourage you - but warn you. You should use DSP with subs like the SI to optimize them. You may get lucky with your room, placement, and some sort of autoeq like the SMS-1, or Audyssey XT32 and the automatic EQ functions are able to give you a desirable flat frequency response and over come the lack of a starting flat FR. Then again - you might not. In any case you won't know until you measure with a frequency response tool.


I'd definately recommend the iNuke DSP 3000 for a pair of SI subs. Hopefully you bought the dual 4ohm voice coil SI model because that's the perfect match. The iNuke 3000 DSP is actually overpowering them a bit at 2ohm per iNuke channel - as it'd be putting about 1,100 watts to each 2 ohm load, but that amount of power won't hurt the SI for realistic typical home theater use.


When it all boils out - I'd prefer a DSP amp with EQ ability that has less power than a more powerful amp without EQ ability - but it's a moot point unless you know how to harness the DSP's ability. A more powerful amp without a DSP ( or some ability to apply EQ) will just make an unpleasent frequency response louder (assuming your subs can handle the power). That's what a "boomy" sub is, or a one note wonder sub. If 40hz is 10 dB louder minimum than every other note the sub produces (which could be a possible outcome of a sealed SI with no EQ) - you've got the very definition of a "one note wonder" subwoofer system. Not cool. Unfortunately, nobody can tell you what DSP settings to use in your room - without measuring your room. If you would like to build a box that will work better without worrying so much about EQ or DSP and you want to go with the stronger amp for future proofing - then the Marty Sub might be a better start - because it basically starts with a flat frequency response - which will most likely give you a bit of a house curve (most people desire) in the typical room and yet will have the native flat frequency response at the higher end of the bass spectrum as a good native starting point without EQ.



Quote:
Originally Posted by bass addict  /t/1517259/to-dsp-or-not#post_24343519


The DSP is a tool to help you "tailor" the FR to overcome room nodes. You first need to find out what you FR is. REW is a great one but has a steep learning curve. A DB meter and some test tones will get you 90% of the way though.


Something as simple as moving your sub 6" can affect FR. Room treatments, when allowed, are critical in tailoring not only your sub, but your entire audio setup.


Myself, if I had a max budget and this meant either a more powerful amp without DSP, or a less powerful one with it; I'd go for the latter (assuming you wouldn't be buying one down the road). If you can afford one later on then that would need to be taken into consideration.

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I should just put this link in my sig:
http://www.avsforum.com/t/1449924/simplified-rew-setup-and-use-usb-mic-hdmi-connection-including-measurement-techniques-and-how-to-interpret-graphs#post_22790110

This is a fabulous guide to REW by AustinJerry. The site itself is a wealth of information, probably way more than you need (or want) to get started.

"I'd definately recommend the iNuke DSP 3000 for a pair of SI subs. Hopefully you bought the dual 4ohm voice coil SI model because that's the perfect match. The iNuke 3000 DSP is actually overpowering them a bit at 2ohm per iNuke channel - as it'd be putting about 1,100 watts to each 2 ohm load, but that amount of power won't hurt the SI for realistic typical home theater use."


Darn it, I didn't. I went with the dual 2 so that I can run them to a 4ohm load. I had read on some of the other posts about a 4ohm load on the 3000 would be a great match as well. So I might be just right on the power but no headroom. Maybe I will wait a little and get the 6000 in case I get the bug and decide to do 2 more 18" subs.


Thanks for the explanation. I will read up on DSP and the thread LastButNotLeast posted.



Quote:
Originally Posted by cessna1466u  /t/1517259/to-dsp-or-not#post_24343426


My problem was with his comment "If you don't want to learn how to measure your FR, then I would suggest you go with a manufactorer's sub instead of DIY." Never did I say I didn't want to learn, I asked if someone like me that doesn't know much about it would be better off getting an amp without it so that I wouldn't mess things up.

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Problem is your question comes across as ignorant (less than optimally informed for political correctness). I know that may not be your intent...but that is often what comes across when reading the words especially when you make a subject title of "to DSP or not". So if you got a "terse" response, don't take offense. Be glad people are responding. It could be worse in which everyone just ignores it.


The fact of the mater is if you DIY and don't measure the response....well, that is mind blowing. It just makes no sense. Every single build thread I have read here has a measured response. Furthermore, all manufactured subwoofer assemblies have some sort of EQ inside them. None of them are a straight plate amp with a speaker attached. So this is why when you make a comment about "skipping out on the DSP" people might get a bit "annoyed". Might as well go to Texas and ask about making Barbecue without smoke while you are at it.

My question was not asking if a subwoofer needs dsp or not. It was should I get the higher power amplifier without DSP and let my Yamaha receiver that has YPAO which is a limited of course, kind of DSP do the equalization or get a less powerful amplifier that has built in DSP and use it to control the equalization. I am not an idiot and think that I can get make a box, screw a subwoofer in it, connect it to a raw amplifier and send a signal to it and expect it to sound great. I know at some point, measurements need to be take, some compensation needs to be done and signals need to be crossed over and sent correctly to the subwoofer.


Both of you read the fact that I was contemplating not getting a an amplifier with a DSP in it and you jumped to the conclusion that I was ignorant, not wanting to learn and had no business being here. Doesn't matter how many times you go back and edit your post, the insinuation is still there.


My question about the minidsp was never answered, and you seemed to never read my comment "I have a receiver with a subwoofer output. The receiver takes care of setting LP crossover setting for the sub output. When I had the Klipsch subs I would turn the Crossover setting on the subs off and let the receiver handle that, I would just control the volume level once on the subwoofer while running the YPAO program on the receiver. Once set, I would then control the levels on the receiver. "


I was talking about skipping out on the amplifier with DSP, my receiver, grant it in a very minor way would take care of the DSP.


I don't see as stupid as a question might be why we can't just answer it, try to help and teach. So you have 4 18" subs and the graph you posted says your room is awesome. I hope one day to also be able to post graphs that say that, but for now I just want to build a subwoofer cabinet, get an amplifier and watch a movie with my family. I honestly don't think that my 10 year old son is going to point out that I have a null, a peak, or that my graph looks wrong. He is going to get blown away by the fact that his father built something, learned something and got to make new friends along the way.


I appreciate all the answers everyone here has, most of you are extremely helpful. I have seen some offer up their shops to build, there are people like Erich that put together awesome set ups for free, all for the enjoyment of the DIY community.


A bad response it not better than no response at all. When someone puts you down for not knowing something it doesn't help in any way. I have seen 18 page posts on someone asking what kind of connectors to use on a subwoofer enclosure, many people wanting to help and give their opinion as to what worked for them and why.


No I am not one of those that believes every kid deserves a trophy for participation. You get exactly what you put into it.