[Bigfishhk]

I have a cd player, integrated amp, song towers and Rythmik F12.
Currently using line in to sub from pre outs and crossing over at 50hz on sub. No bass management control on my int amp.
Decent enough.

But I'd like to try X/O at 80hz. Using the current set up I would be overlapping sub and mains between 40-80hz which I believe will likely cause cancellation, though it sounds better than it should!
Rythmik suggest the only option with my equipment is connect stereo RCA's from CD player IN to SUB then the line out from SUB to amp RCA inputs.
Keep mains hooked up to int. amp.
I guess the sub will then control the X/O frequency to the mains. Seems a bit weird but I may try it.

Anyone tried this?

thanks

Tom

 

[Gzerro]

I can't say that I have tried this, but it seems to me that Rythmik's suggestion may work. This wouldn't be practical for most folks because most people have 2 or more sources (turntables, CD, Streamer, etc, etc) so it would require swapping cables every time you change sources.

One problem I could see would be volume control. I think you would need to control the volume at the CD player instead of the integrated amp in order to get the sub volume in balance. If it is just a straight line level output from the CDP, the sub would be at a fixed volume and have no way to adjust volume when you change volume on the intregrated amp. If your CD player can do that, you should be fine.

Good luck. I look forward to see how it works out for you.
Tom

[Austin08]

I can't say that I have tried this, but it seems to me that Rythmik's suggestion may work. This wouldn't be practical for most folks because most people have 2 or more sources (turntables, CD, Streamer, etc, etc) so it would require swapping cables every time you change sources.

One problem I could see would be volume control. I think you would need to control the volume at the CD player instead of the integrated amp in order to
get the sub volume in balance. If it is just a straight line level output from the CDP, the sub would be at a fixed volume and have no way to adjust volume
when you change volume on the intregrated amp. If your CD player can do
that, you should be fine

Good luck. I look forward to see how it works out for you.
Tom

100% agree with Tom

[Bigfishhk]

yup, you are very correct. Called rythmik and since my cd player doesn't have volume control it won't be a useful solution to connect as proposed.

Wondering what fellow ST owners and sub owners are doing, if like me they don't have bass management in their amp and running ST's full range?.
I think 50hz will be safer way to go so there's little overlap but any any other feedback and experience is really appreciated.

I have adjusted phase best I can with SPL meter and test tones. And I've run the 80hz X/O on sub (ie overlapping with ST's) listening to reggae and electronica.. sounded pretty good with all that bass, but probably not the best way for other types of music!

thanks
TOm

[doug s.]

you could get an outboard active x-over; set the rhythmik's x-over at its highest setting, then set the active x-over at 50-80hz, low-pass to the sub amp, hi-pass to the salk's amp.  and use the active x-over to balance the levels between the sub and the salk's.  i think you will also find a quality active x-over will be much more transparent than that in the sub's amp...

doug s.

[Gzerro]

And I've run the 80hz X/O on sub (ie overlapping with ST's) listening to reggae and electronica.. sounded pretty good with all that bass, but probably not the best way for other types of music!

If you are listening at low to moderate volume, the boost in bass may be desirable (similar to a "loudness" switch or Dynamic Volume). At lower volumes our hearing is less sensitive to bass frequencies. At higher volumes I think you will find running that way will have too much bass and sound boomer.

Or maybe you just like a lot of bass, which is totally ok as well.

[TJHUB]

you could get an outboard active x-over; set the rhythmik's x-over at its highest setting, then set the active x-over at 50-80hz, low-pass to the sub amp, hi-pass to the salk's amp.  and use the active x-over to balance the levels between the sub and the salk's.  i think you will also find a quality active x-over will be much more transparent than that in the sub's amp...

doug s.

While this is likely true, you can't use an outboard crossover with an integrated amp with that sub.   

OP:  The best solution for you is to run your Salk's full-range and let the sub over lap.  There is really no harm in that as long as you have the sub and mains in phase at the overlap point.  That Rythmik sub is very musical, and should blend very well with your Salk's.  You may not need a low-pass of 80Hz with the Salk's, but you won't know that unless you measure the in-room frequency response.  80Hz is a good place to start though.   

You are likely experiencing room modes from the sub.  This will make some genres of music have tremendous bass, and others not enough.  It's my opinion that any sub used for music should be EQ'd for the room.  If you can't do that, then you need to find the best location for the sub where it has the flattest overall response.  You can primitively do this with a db meter and test tones.

The easiest primitive way I know to get the sub in phase with your mains is to set the sub's low pass at 80Hz, play a test tone of 70-80Hz, and simply adjust the phase to get the most output at that frequency.  That will show the sub and mains are in phase.  Then adjust the sub's level to taste if you must.

 

 

[doug s.]

While this is likely true, you can't use an outboard crossover with an integrated amp with that sub.   

OP:  The best solution for you is to run your Salk's full-range and let the sub over lap.  There is really no harm in that as long as you have the sub and mains in phase at the overlap point.  That Rythmik sub is very musical, and should blend very well with your Salk's.  You may not need a low-pass of 80Hz with the Salk's, but you won't know that unless you measure the in-room frequency response.  80Hz is a good place to start though.   

You are likely experiencing room modes from the sub.  This will make some genres of music have tremendous bass, and others not enough.  It's my opinion that any sub used for music should be EQ'd for the room.  If you can't do that, then you need to find the best location for the sub where it has the flattest overall response.  You can primitively do this with a db meter and test tones.

The easiest primitive way I know to get the sub in phase with your mains is to set the sub's low pass at 80Hz, play a test tone of 70-80Hz, and simply adjust the phase to get the most output at that frequency.  That will show the sub and mains are in phase.  Then adjust the sub's level to taste if you must.

bigfishk mentioned his integrated has preamp outs; i assumed it would also have main inputs.  if it does, then the hi-pass outs from the active x-over would go to the main inputs of the integrated.  if the integrated doesn't have main inputs; you're correct; it won't work.  ime, it is good to actively cross mains when using subs, because both the amp and the speakers perform better when relieved of having to do low-bass duties.

regarding room node issues, the easiest way to deal w/that is to run two (or more) subs, to even out standing waves.  it is really difficult to get smooth bass in a room over a wide area, w/a single sub.  and, my experience has also been that, regardless of what is said about (lack of) directionality of low frequencies, soundstaging is better w/a pair of stereo subs.

ymmv,

doug s.

[TJHUB]

bigfishk mentioned his integrated has preamp outs; i assumed it would also have main inputs.  if it does, then the hi-pass outs from the active x-over would go to the main inputs of the integrated.  if the integrated doesn't have main inputs; you're correct; it won't work.  ime, it is good to actively cross mains when using subs, because both the amp and the speakers perform better when relieved of having to do low-bass duties.

regarding room node issues, the easiest way to deal w/that is to run two (or more) subs, to even out standing waves.  it is really difficult to get smooth bass in a room over a wide area, w/a single sub.  and, my experience has also been that, regardless of what is said about (lack of) directionality of low frequencies, soundstaging is better w/a pair of stereo subs.

ymmv,

doug s.

I completely agree with you Doug.  I practice everything you've stated.  I was just responding to what the OP could do with the current gear listed.  It's not idea, but with some care, very good sound could be achieved.  Would I do it this way?  No.

[doug s.]

mebbe bigfishk will let us know whether his integrated amp has main inputs, as well as preamp outs.  if so, at the wery least, an active outboard x-over could be tried relatively painlessly....

doug s.

[Bigfishhk]

the integrated amp (krell kav 400xi) does not ,I believe, have MAIN INPUTS.

copied from Krell manual:

INPUTS
All with Theater Throughput
1 pair balanced via XLR connectors,
3 pair single-ended
via RCA connectors

OUTPUTS
2 loudspeaker via 5-standard
binding posts,
1 pair single-ended
preamplifier via RCA connectors
TAPE INPUT AND OUTPUT
1 pair single-ended via RCA
connectors.

I just started to do what Doug suggested- overlapping ST's and sub, X/O at 80hz.  Phase - Using SPL meter I found that loudest reading between 110- 180 degrees. So I set it at 180 rather than 110. Is that the right choice given the 110-180 range?

I must admit the bass is impactful with this set up but I 've not really had time to listen very critically. Hopefully this weekend.

What sonic defects should I listen for if the overlap creates cancellation issues etc?

ps I only have one sub and am very unlikley to get a 2nd unless I move house! It's an f12 and it's doing well in the listening area of a large room.

thanks for these comments. they really help.

Tom
 

[Bigfishhk]

You are likely experiencing room modes from the sub.  This will make some genres of music have tremendous bass, and others not enough.  It's my opinion that any sub used for music should be EQ'd for the room.  If you can't do that, then you need to find the best location for the sub where it has the flattest overall response.  You can primitively do this with a db meter and test tones.

The sub has Parametric EQ but I have no bloody clue how to do that, despite reading some info on the website. .but maybe this is the route to deal with room nodes?

[Gzerro]

The sub has Parametric EQ but I have no bloody clue how to do that, despite reading some info on the website. .but maybe this is the route to deal with room nodes?

Yes the PEQ on the sub will help, not a complete solution but will help with the single worse peak. In order to set it correctly you need to be able to measure the frequency response of the room. You can do this with test tones and an SPL meter - a good resource is here:
http://www.realtraps.com/test-cd.htm
Once you know what your in-room frequency response looks like, you can use the PEQ to cut the frequency with the highest peak (best not to try to boost nulls). This will be a tedious process, but well worth it. Better yet would be to get REW - much much faster but there is more of a learning curve initially, and you will need a PC with soundcard. You can use your SPL meter for the mic. Link is here:
http://www.hometheatershack.com/roomeq/

[doug s.]

...I just started to do what Doug suggested- overlapping ST's and sub, X/O at 80hz...

tom, i think you misunderstood what i was suggesting - i was suggesting not overlapping st's and sub, but purchasing an outboard x-over so you can eliminate the st's output below, say, 80hz...  but, since your krell does not have main inputs as well as preamp outputs it's not so simple. 

but... your krell does have a true tape loop - this means you could use a high-pass-only crossover set at, say - 80hz, install it in the tape loop, and your speakers would be high-passed at 80hz when the tape loop is engaged; and the sub's crossover would low-pass the sub at the 80hz setting on it.

marchand makes a really hi-quality hi-pass passive x-over that you could use for this purpose, but it retails for $295.  if you wanted to experiment for less, you could buy some harrison labs fmod high-pass filters and install them in your tape loop.  they are ~$26 a piece from parts express:

http://www.parts-express.com/wizards/searchResults.cfm?srchExt=Mfg&srchMfg=265

a pair of 12db/octave 70hz or 100hz hi-pass crossovers would set you back $52 plus shipping, plus the interconnects you would need to hook up to your tape loop.  (for $156, you could effect a 24db/octave 60hz or 100hz hi-pass crossover by using a pair of the 12db 30hz or 50hz units, w/a 3db attenuator in between them - this is per harrison labs.)

also, i have found the best results for smooth response - and also least negative impact to soundstaging when using a mono sub - place the sub equidistant between the main speakers, and as nearfield as possible - at your feet would be best.  when the sub is close to you, the room nodes will more likely be somewhere where you are not.  having it nearfield also helps, as you don't need it as loud, so there will be less distortion.  you can always relocate it when not in use... 

doug s.

[TJHUB]

The OP actually misunderstood me.  My suggestion to overlap the sub with mains and use the single test tone at 70-80Hz range was my idea to purely get the sub in phase with the mains.  After that, adjust the low-pass of the sub where it seems to sound the best for you.  If your sub and mains are in phase at the overlap, they are in phase everywhere else too.  So don't worry about phase issues once you've got it nailed down.  I too would just set it to 180 and don't look back.

Personally, I don't think overlap is a bad thing at all.  It really becomes an issue if the sub is a piece of crap that is just boomy bass.  That Rythmik is awesome, and VERY musical.  It is well worthy of overlapping the Salk's.  I'd do it and not think twice about it.

Doug offers some really great advise above.  I use those high-pass filters from Parts-Express as well, and they work great.  Sonically, I'd call them nearly transparent.  They work just enough to take the bass load off my Salk's and let my subs do their jobs.  Offloading the bass from my main speakers really does seem to cut down on distortion as the midrange comes off cleaner sounding with the filters in place.  However, I love those PE filters because I don't need any extra interconnects to use them.  I have one on the input of each of my monoblock amps, and I couldn't be happier. 

If I were the OP, I'd try using those test tones and a db meter to plot the bass response as best I could.   Then use the sub's parametric EQ to knock down the largest peak between 30 and 80Hz, and just listen like that for a while.  Then I'd try the PE filters in the tape loop.  You also don't need to go -24db on them either.  My -12db slope at 70Hz works great.  They remove a tremendous amount of bass from my mains.  Certainly enough for things to sound absolutely wonderful. 

[Bigfishhk]

Wow
That,s a ton of great info to get my head around. Will take it step by step with some of these suggestions.
Challenge for me is to decipher some of the info but will persevere.
Thank you
Tom

[Bigfishhk]

Code: [Select]

If I were the OP, I'd try using those test tones and a db meter to plot the bass response as best I could.   Then use the sub's parametric EQ to knock down the largest peak between 30 and 80Hz, and just listen like that for a while.  Then I'd try the PE filters in the tape loop.  You also don't need to go -24db on them either.  My -12db slope at 70Hz works great.  They remove a tremendous amount of bass from my mains.  Certainly enough for things to sound absolutely wonderful. RYTHMIK WEBSITE INFO ON PEQ DOESN't EXPLAIN CLEARLY ENOUGH, for me anyhow, HOW TO CHECK LARGEST PEAK, THEREFORE ANY LINKS OR INFO REALLY APPRECIATED. SORRY FOR ASKING SO MANY QUESTIONS.THANKSTOM

[Gzerro]

The link I posted above tells you how to check for the largest peak:

http://www.realtraps.com/test-cd.htm

The process basically goes like this after you download the files and burn to CD:
1) Play the "pink noise" file to calibrate your system to a certain volume, say 65db (as measured with your SPL meter at the listening position).
2) Then there are test tones 1Hz apart from 10hz to 200Hz (you will only need to use the tones below whatever crossover point you choose)
3) Play the files and read your SPL meter to see how loud it plays at each frequency and write it down. You will have a table that looks like this:
Tone   Reading
20Hz   85db
21Hz   87db
22Hz   86db
etc.
... all the way from 20hz to your crossover point.

Once you are done, graph the readings. The line will be wavy, likely with 20+db variances or even larger. You will have have "nulls" (sound waves cancelling each other out, so very low volume) and "peaks" (sound waves reinforcing each other - very high volume).

So that is how you identify the peaks/nulls in your room.

A few notes:
1) If you move the sub, or where you take the measurements EVERYTHING changes. The response isn't equal throughout the room. That is why people spend a lot of time figuring out the best place for their subs.
2) If you have a large peak, it can be VERY loud and could damage your sub. The test tones are 20db louder than the pink noise. Be careful and turn down the volume if you need to. You may want to calibrate 10db lower than the instructions say. Always be very careful with test tones, they are deceptively loud.
3) Doug recommended placing the sub close to your listening position. If you can this will even things out at your listening position and I would highly recommend following his advice if your room/WAF allows. The larger your room, the bigger the difference this will make.

Once you identify the highest peak, the PEQ (Parametric equalizer) has three knobs - Gain - how big of an adjustment you want to make
- Width - how wide a frequency you want to effect (a narrow spike or a broad hump)
- Frequency - the frequency of the center point of the adjustment.

Adjust the knobs to roughly match the shape of your peak.

Once you make the adjustment, it is best to remeasure to see how well it worked. It may take a few tries to get it right.

I hope that is helpful.

Good luck!

[Bigfishhk]

Once you identify the highest peak, the PEQ (Parametric equalizer) has three knobs - Gain - how big of an adjustment you want to make
- Width - how wide a frequency you want to effect (a narrow spike or a broad hump)
- Frequency - the frequency of the center point of the adjustment.

Adjust the knobs to roughly match the shape of your peak.

I am going to make time to do this. Big thank you for the time you put into explaining this. Regarding the PEQ adjustments as per above, I will try to implement if I can figure out the measurements the way you describe. (nothing wrong with your description, just my own technically challenged brain!)

TB

[Gzerro]

Good luck! If you want to post your measurements we can help with the PEQ settings.

If this sort of thing is interesting to you, I would highly recommend this book by Toole. It has an excellent section on bass management which will help you come to terms with all the jargon.

http://www.amazon.com/Sound-Reproduction-Acoustics-Psychoacoustics-Loudspeakers/dp/0240520092/ref=sr_1_1?ie=UTF8&qid=1331321899&sr=8-1

Lastly, if all of this seems like entirely too much work and gets frustrating, just remember that the most important thing is to enjoy yourself. You have a fantastic system that will sound great even if it isn't "perfect". Alot of us here get carried away on the details because the tweaking is part of what we enjoy.