Is there a subwoofer amp with room correction?

claytonJ2

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I have a ServoDrive Contrabass and I'm driving it with an Outlaw 200watt mono amp. I'm wondering if there's an amp available with room correction built in? Or should I just get an Integra 80.2 (or 3 when those come out) and let that handle the correction? I'm also using an old M&K 12 inch for fill in as the big gun can't be bothered to reproduce low volume sounds.

Sidenote: The Contrabass isn't in a finished cabinet. Oscar is written on it in pencil, so that's what we call "him". Is that something that would have been written by the manufacturer?
 

Kal Rubinson

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I have a ServoDrive Contrabass and I'm driving it with an Outlaw 200watt mono amp. I'm wondering if there's an amp available with room correction built in? Or should I just get an Integra 80.2 (or 3 when those come out) and let that handle the correction? I'm also using an old M&K 12 inch for fill in as the big gun can't be bothered to reproduce low volume sounds.
The Integras with XT32 will do a good job of integrating (sic) your two different subs. OTOH, the very excellent Rives Audio sub-PARC might be a great match to the Contrabass.
 

amirm

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Instead of an amp, how about a dedicated room eq for the subs? Here is the JBL BassQ: http://www.jblsynthesis.com/ProductDetails.aspx?prdid=89



Controls up to 4 subs. We have one in our shop but sadly, I have not played with it :). But Roger Dressler has one (of Dolby fame) and seems to like it.

The BassQ uses Harman's sound field management which first equalizes the response of multiple subs and then EQs them as a group. Likely is better than anything built into an AVR or mass market processor.
 

Ron Party

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Instead of an amp, how about a dedicated room eq for the subs? Here is the JBL BassQ: http://www.jblsynthesis.com/ProductDetails.aspx?prdid=89



Controls up to 4 subs. We have one in our shop but sadly, I have not played with it :). But Roger Dressler has one (of Dolby fame) and seems to like it.

The BassQ uses Harman's sound field management which first equalizes the response of multiple subs and then EQs them as a group. Likely is better than anything built into an AVR or mass market processor.

That's exactly what I'm using and I second Amir's recommendation.
 

JackD201

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I would go with a stand alone processor as well.
 

Kal Rubinson

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Anyone compared it to the Antimode? I was planning to upgrade to a pre/pro but circumstances have me considering stand-alone bass control for my pair of subs.
The AnitMode is a completely automatic unit with the capability of only 2 mic positions and no multisub control. (Y connectors notwithstanding.) I would think that the hand's on abilities of the miniDSP might be more up your alley. I am happy with XT32 at the moment.
 

DonH50

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Thanks Kal, that helps. I am leaning toward an Integra 80.x and the pro package; kinda' wish the Marantz had XT32. Maybe next year's models... In the meantime, I was looking for a way to add sub EQ (etc.) to my Pio unit. I do pretty well with MCACC and then tweaking FR with my own measurement setup, but I do admire those ruler-flat XT32 plots everybody throws out!

The SW I use (R+D, with the filter package) allows me to program filter settings for the little Behringer units and a few others, but I am getting lazy in my old age. I'd rather listen than tweak (don't tell the IEEE; they might revoke my membership!) - Don

p.s. Looked up the miniDSP -- interesting! Hmmm... Anything you don't know, Kal? Ever think about, I dunno', writing for a stereo magazine or something? ;) Thanks again! - Don
 

Kal Rubinson

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Thanks Kal, that helps. I am leaning toward an Integra 80.x and the pro package; kinda' wish the Marantz had XT32. Maybe next year's models... In the meantime, I was looking for a way to add sub EQ (etc.) to my Pio unit. I do pretty well with MCACC and then tweaking FR with my own measurement setup, but I do admire those ruler-flat XT32 plots everybody throws out!
I fully understand that. OTOH, note that those ruler-flat XT32 plots everybody throws out are not really objective measurements, such as you would get with R+D. They are considerably smoothed and are based on applying the idealized filters to the original measurements, not displays of post-filtered measurements.

I'd rather listen than tweak (don't tell the IEEE; they might revoke my membership!)
Me, too.
 

DonH50

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Ah, I was misled when they said "post-Audyssey response"; did not realize they were not measured, just predicted by the SW. Grrrr...

Thanks Kal,

Back to cleaning up the grill to cook lunch! - Don
 

DonH50

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Well, no, but isn't that what you were implying? Unless we are now talking about my predictions about what my wife wants to hear; those are inverses, and for my part frequently require complex arithmetic with imaginary numbers. :)

One of the "issues" I have tweaking myself is that I can improve FR but MCACC does not allow me to tweak the phase/group delay. Granted few might be able to do that, but I do wish they'd let me. That, and the fact that I can save the data to a PC, but not play with it and upload back to the AVR, have me wanting just a little more.

Did I remember rightly that you have, or are doing, a review of the Integra (80.x)? Is it (the review) out yet? I know you said you liked the Marantz (7005), and I can't afford Meridian.

I suppose I should pick up a miniDSP to play with, but I waste too much time posting these days. - Don
 

Kal Rubinson

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Well, no, but isn't that what you were implying? Unless we are now talking about my predictions about what my wife wants to hear; those are inverses, and for my part frequently require complex arithmetic with imaginary numbers. :)
Trust but verify. All I am saying is that the Audyssey post graphs are predictions and are probably done properly, in experience. It is probably the smoothing that bothers me most since I like to know what is under the make-up.

One of the "issues" I have tweaking myself is that I can improve FR but MCACC does not allow me to tweak the phase/group delay. Granted few might be able to do that, but I do wish they'd let me. That, and the fact that I can save the data to a PC, but not play with it and upload back to the AVR, have me wanting just a little more.
Sure. Audyssey Pro will let you do the latter but not the former.

Did I remember rightly that you have, or are doing, a review of the Integra (80.x)? Is it (the review) out yet? I know you said you liked the Marantz (7005), and I can't afford Meridian.
July Stereophile.

I suppose I should pick up a miniDSP to play with, but I waste too much time posting these days. - Don
I have the same problem.
 

Nyal Mellor

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but I am getting lazy in my old age. I'd rather listen than tweak (don't tell the IEEE; they might revoke my membership!) - Don

Hey Don....couple of things:

I don't believe correcting above say 200Hz or so is the optimal way to go about things. Far better if you have space and budget to utilize passive acoustic treatment to deal with problems above this frequency and use EQ to deal with modal resonances in the area of the frequency spectrum where room modes are sparse and most powerful.

In any event I would not trust an automated room correction device. Even the best ones out there e.g. Meridian Room Correction, BassQ can give different results from run to run which shouldn't be the case. They can also put EQ in places where it is not going to do anything and be even counter productive e.g. the algorithm tries to correct frequency deviations that are boundary interference related.

You should always have a means of validating the results of the automatic equalization. A measurement system is a requirement to get involved in this area if you are aiming for truly high end results.

In any event if you know what you are doing (and it is true that few do since it is a complex area - you have to consider room mode decay time, room mode bandwidth, excess group delay and frequency response before creating a filter with the right attenuation, Q and center frequency) it is nearly always possible to get better results with manually setup parametric EQ.
 

Kal Rubinson

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In any event if you know what you are doing (and it is true that few do since it is a complex area - you have to consider room mode decay time, room mode bandwidth, excess group delay and frequency response before creating a filter with the right attenuation, Q and center frequency) it is nearly always possible to get better results with manually setup parametric EQ.
True but that is a big conditional. Not many qualify.
 

audioguy

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In any event if you know what you are doing (and it is true that few do since it is a complex area it is nearly always possible to get better results with manually setup parametric EQ.

The issue I have with PEQ is that I have yet to hear a PEQ solution that can deal with bass ringing as well as a reasonably well done time based solution. And even the time based solutions are not all created equal.

I have (at least I will when it gets returned from repair) an Integra 80.2 with the latest Audyssey capabilities and a TacT 2.2XP. While I can get the corrected response curves of the two technologies really close (measured via and external measurement system like XTZ or OmniMIc), I can assure you the bass ringing is far more improved with the 80.2 than with the TacT. That was not the case with the previous version of Audyssey but this version has far greater granularity in the filters for the bass/midbass portion of the audio spectrum. Once I get my 80.2 returned (I have no clue when that might be) I can post the measured results of bass ringing from XTZ. But I don't have to measure it to hear it -- nor have other experienced listeners. And in my experience, PEQ would be a distant third. As an aside, my room is very well trapped -- all four corners and the soffits.

I don't claim to be a PEQ expert but in my experience, I have much more confidence in some of the more reasonably well done time-based correction technologies.
 

DonH50

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Hi Nyal,

Thanks, understood. I use R+D software on an old notebook with a Creative outboard sound card, m-audio preamp, and Earthworks measurement mic (probably worth more than all else put together). That provides very flat response without a lot of money (<$2000 USD plus notebook), and saves breaking the good preamps out of my recording system just for room measurements.

My room is well-treated; probably too much so, but I do not mind a fairly dead room. I realize I am giving up some of the "spaciousness" of my Maggies for pin-point imaging across the couch; I can live with that, at least better than the comb filtering effects I would otherwise experience. There are pix on this site in the reader's rigs area.

I don't have any real problem doing better than MCACC for frequency response (though I can't tweak phase/group delay with the AVR), it just takes a little time. Quiet time, harder to find with the kids home for summer! R+D uses a combination test signal (impulse plus noise) so by looking at the time and frequency domains I can dial it in fairly well. The Pio unit does include three PEQ bands, which unfortunately do not cover the low bass region (< 50 Hz or so). My subs have a single-band PEQ I use for that, along with all the absorbers. I rarely use waterfalls because I am less familiar with them and the AVR's filters won't do much about them (i.e. time decay, RT60 etc.); I depend upon the room treatment for that.

One thing I have noticed is that my measurements virtually overlie from run to run unless there's a good reason (e.g. somebody opening the door during a run). I have enough treatment that comb effects are minimized, at least through most of the range, so moving the mic a little does not significantly change the response. I do have some room modes to deal with and a few upper bass/lower midrange bumps I smooth out, but overall the system is about +/-3 dB with a few narrow spikes to +/- 6 dB from roughly 10 Hz to 20 kHz using 1/12-octave smoothing. I do shelve the region above about 12 kHz down about 3 - 6 dB as I can't hear that anyway (getting old) and prefer to save my ribbons.

My main interest in XT32 and things like miniDSP and BassQ are for the regions from 200 Hz down; I agree with you on that. The biggest drawback Pioneer's MCACC has, IMO, is their lack of anything below 60 Hz. Some people claim that is advantage and it allows you to use an outboard dedicated sub unit; I feel it is a shortcoming of MCACC, most likely related to processing power in the AVRs. I also prefer more PEQ bands, and more regular graphic EQ bands for that matter, than my Pioneer offers. Finally, I prefer to do the processing digitally, where I have more control over the filters and can design much steeper linear-phase or apodizing designs with essentially zero noise and drift compared to analog, and prefer to eliminate the extra A/D-D/A conversions that an outboard unit requires.

As I have said and Kal has noted (methinks he knows me a little too well ;) ), should I upgrae to an XT32 unit, I would purchase the pro package so I could piddle.

I appreciate the insights offered by you, and Kal, and everybody, thank you! I have probably diverted this thread enough... - Don
 

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