Small vs Large speakers when using a sub (1 Viewer)

[Edward J M]

If my making JUST the mains Large I am asking the receiver to reproduce bass on all the channel then why would it be necessary to even give the listener the option of setting their surrounds and rear surrounds independent of the main channels? This same question also applies to the center channel, too.

Brae:

I think these are all the bass management scenarios the typical HT receiver is capable of handling.

1) If you set the sub to yes, and all the speakers to small, the sub receives the LFE channel, AND the sub also receives bass below your selected crossover frequency from all the other speakers.

2) If you set the sub to yes, and all the speakers to large, the sub only receives the LFE channel, and all the remaining channels receive a discrete full range signal.

3) If you set the sub to yes, and the mains to large, and the remaining speakers to small, the mains receive a discrete full range signal, the sub receives the LFE channel, AND the sub receives the bass below your selected crossover frequency from any speakers set to small.

4) If you set the sub to no, and all the speakers to large, all channels receive a discrete full range signal, AND the LFE channel will be redirected to the mains.

5) If you set the sub to no, and the mains to large, and the remaining channels to small, the mains will receive a discrete full range signal, AND the LFE channel will be redirected to the mains, AND the bass below your selected crossover frequency from any speakers set to small will also be redirected to the mains.

Hope this helps instead of confusing further.

Regards,

Ed

 

[Mike Sloan]

Brae:

In terms of SPL, in the THX/Dolby/DTS world, reference level refers to a playback system where the loudest signal (0dB FS -- 0 dB referenced vs. a Full Scale Signal -- as loud as you can store) is 105dB for regular speakers, and 115dB for the LFE channel delivered to the seats.

When calibrating THX gear, the internal test tones are set at -30dB FS -- this means 30dB below the loudest possible encodable signal. When we use our SPL meter, it should read 75dB for all speakers. The 10dB pad for the LFE channel is accounted for, and it to should be calibrated to 75dB. Although, a few like to calibrate 3-5dB hot.

When using a test disc, like AVIA the test tones are recorded at -20dB FS (20dB below the loudest possible signal). When using AVIA your target SPL is 85dB, and this should be done with the volume control set at 0dB (if calibrated from -xxdB to +xxdB) or to REF if your receiver/processor has such a spot. Now when you pop in a DVD and set your volume to your "calibrated" reference spot you should achieve peaks of 105dB at the seating position ....I think you knew this and you are pulling my leg...I'll bite at anything!

By the way, I went back and set my mains to large...but I sent only the LFE to the sub(instead of the blended LFE/main signal)and it sounded really full! So maybe it's not cut and dry...I still don't like jammin my mains that hard...I treat them better than my children!!

 

[Brae]

Edward J M, I agree 100%.
Dan Hine, I do understand the nature of the power requirement vs. dB volume increase. Sorry for any confusion, but Pioneer likes to keep us all confused. You see, the Master Volum on their Elites read in dB, but these values are not true dB in terms of volume as a function of power output.
Sorry if I accidentally confused anyone. I've already offered my negative views to Pioneer for this misleading nature of the Master Volume indicator when they confirmed the dB means nothing for the volume on their products. Essentially, they could have used lettrs instead of numbers, hehe.
What should be interesting is I could perform a per-channel factory-default test where I would find the ceiling (marked by threashhold audible distortion) and measure the SPL (using the RS 33-2050) and then lower the Master Volume on that channel until the SPL drops 3dB, which I beleive would indicate a halving of the acoustical energy for said channel speaker. Correct? I could also do this from 1-meter away to be truly anal about it.

 

[Dan Hine]

on their products.

I added the bold to point out the part of the quote I was focusing on
Of course not. And it isn't supposed to. Different speakers have different efficiencies and therefore the number on the receiver cannot dictate the actual volume since it will be different for each speaker, each room, etc... And I'm sure you know this. What I think you are misinterpreting though is this:
Unless Pioneer has changed how they do things since I got my Elite 35tx the readout is db below reference (-db) with 00 db being reference. Mine starts at -80db which is essentially "off." When you use the internal test tones of the receiver it cycles all the way up to 00db, or zero attenuation. Interestingly enough this gives me 75db on my spl meter +/- a few db for varying speaker efficiency and position/distance which I then adjust up or down to achieve proper calibration. But in the end all the speakers are adjusted to give me 75db at the 00db position.
So with all my speakers calibrated to 00db, if I am watching a movie at -10db I know that I am watching it at 10db below reference. Could it be a db or 2 off as it moves away from reference? Maybe, but as long as all the speakers are calibrated to each other then you shouldn't really care, IMO.
Anyhow, this approach is preferable IMO since it actually tells you something. If a volume display reads 0-120db then what happens if you have 95db efficient speakers like Klipsch or my Adire HE10.1's? Is it really 95db when the readout says it? Probably not. The same for people with 86db efficient speakers.
Though I guess YMMV.
Dan

 

[Brae]

Quote:

Good example, and something I originally thought, too! BUT, Pioneer says, "it doesn't work like that." They went into speaker efficiencies (sensitivities), etc., and when I hypothosized the ideal 8-ohm speaker load with the perfectly flat, 8-ohm impedance curve example, they still refused to accept your quote directly above this comment! It was very frustrating talking with the ambiguous Pioneer Tech people. One always walked away with more uncertainty than before the call.
This is why I suggested to others, both here on HTF and on AVS, to try testing their standalone Elite receivers and when they observed a 3dB drop on their trusty SPL meters see how many notches they turned down on their Master Volume. Personally, I do not think many, if any, pre-pro and integrated receiver manufacturers care to educate (i.e. arm) its buying consumers with the tools (weapons) to investigate their purchased products.

 

[Dan Hine]

I fully acknowledge that its probably impossible for one to have a Master Volume report true dB of acoustical energy or amplified power output (although I bet one could!

Someone will correct me if I am wrong but db is not a measure of amplified power. It is a measure of the sound pressure created by said amplified power. I think it would be pointless to have a preamp/receiver show the "true db" as opposed to a general placement relative to reference level in the room because it would be changing constantly. At any given time the power being put out by the amp stage is fluctuating according to the programs dynamics. When playing at Reference level it isn't a constant 105db (115db in the LFE). It is my understanding that those are the peak volumes. So if the Elite says 10db below reference then I would think that it is in the ballpark. Are you saying that Pioneer stated that at -10db on the receiver the peaks NEVER actually reach 10db of reference level? Or that the peaks higher than they should be?
That's the only thing I can think of to make sense of your dispute with the unit. Because of course at -10db on the Elite it won't be a constant 95db spl. That would be a rather boring soundtrack.
I feel like I'm the only one, but I am very confused as to what you are expecting and what you feel you are getting.

 

[Michael E]

Link Removed
Referencing the above article:
If Brian is right in his article then it seems the best way to to approach bass management is outside the receive/preamp/processor. Set all speakers to larges and then use an external bass management device like an ICBM we can then be certain that all material on the LFE is getting through and the speakers are getting what they can handle. I am curious why receive/preamp/processor manufacturer's have not pick up on this yet.

 

[Brian Bunge]

Dan, I follow what you're saying and I think I follow what Brae is saying. For the record, I agree that the volume indicator is merely useful as a reference as to how close you are to true reference of 00dB (did I say that right?).

Brae, expecting the difference in the reading of your Radio Shack SPL meter to correspond to the change you've made in your volume control (3dB louder on the volume control reading 3dB louder on your meter) is a big mistake. The Radio Shack meter is by no means a precision instrument (it's only $35-$40 after all). It's level of accuracy is frequency dependent, and can be off as much as 7dB at 20Hz, IIRC. So don't use that to try to prove anything about your Pioneer receiver (or any other).

Also, I have no experience with the M&K subs but if it's got dual 15" drivers it's a least a step in the right direction for your room size. BTW, what does it cost retail and actual street price?

 

[Mike Sloan]

Also, I have no experience with the M&K subs but if it's got dual 15" drivers it's a least a step in the right direction for your room size. BTW, what does it cost retail and actual street price?

Drivers: (2) 12" long-throw. Magnetically shielded in a Push-pull configuration. Selectable low-pass filters.
Internal Amp Power: 150 watts RMS
Dimensions: 23" H x 15.25" W x 19 5/8" D
Weight: 75 lbs.
Suggested Retail Prices:
MX-150 in Black Lacquer Bead Finish $1399 each
MX-150 in White $1499 each

This is a great sub..but frankly, the VTF-3 is every bit as good...and the SVS 25-31PC Plus is even better. I had the MX-150 for a while and opted to get (2) VTF-3's for almost the same price! Dual VTF-3's exceeded the 150 in every respect. Where the M&K has it is in quality of components. Will see if the VTF-3 passes the test of time. M&K is a protected line and if it is not sold by a certified dealer (based on the serial#)M&K may not honor the warranty!

 

[Evan M.]

ok, i probably should not be sticking my VERY amateur nose into this but i am unsure of a few things. all this db and spl talk makes me feel as if i am in high school algebra again . (can you tell i am new to this)....anyway, i just replaced my fronts with boston acoustic vr965's. they have a powered 8"woofer in each speaker. the amp is rated at 80 watts. to me it is more like a powered woofer than a powered sub. it is rated down to 29hz. i keep them set to large in both ht and music. i do not have them connected via l.f.e., i use a separate sub for that. my rational for setting them to large is to use the speakers ability to handle pretty low lows and use the sub for the l.f.e. i also figure that because the speakers woofers are powered it will help relieve a lot of the stress the receiver will have with the lower ranges. i do set the center and surrounds to small. for music there is simply no comparison. setting the speakers to large simply sounds better. for ht there is not as much of a difference but it still sounds fuller when set to large. we just finished watching lotr and it sounded very full and dynamic. when i saw the movie set to small i felt as if i lost too much of the low middle range frequencies. am i correct to assume that with powered towers the receiver will not be as stressed since the speakers have amps to "help". anyway, i apologize if i opened up a different can of worms or maybe someone already posted the same thing i did and i just didn't understand all of the technical jargon

 

[Mike Sloan]

The boston acoustic vr965's are really nice sounding speakers...I love how smooth the tweeter is! I think as long as you like it and it sound good...then keep it that way. You may have a bass friendly room where cancellations are kept to a minimum from a multi point source. Since the Subs are self powered you will not be robbing any power from your receiver...so you have set it up correctly.

 

[Lewis Besze]

Not according to the manual for my receiver, but then I suppose you either know something I do not, or know something Pioneer does not. Please tell!!! If my making JUST the mains Large I am asking the receiver to reproduce bass on all the channel then why would it be necessary to even give the listener the option of setting their surrounds and rear surrounds independent of the main channels? This same question also applies to the center channel, too.

What I meant is that,which ever channel you select as large,that must carry the full burden of bass of that channel only.Any channels being select as small it is highpassed to the sub still.So if your mains are large then no bass info from that channel go to the sub.
The point I was making that if you select your mains as large,then if a certain frequency is beyond it's "reach" then it will be lost,since it won't be sent to the sub.
I hope that clears it up.

 

[Steve_Ma]

From Lewis:

3) If you set the sub to yes, and the mains to large, and the remaining speakers to small, the mains receive a discrete full range signal, the sub receives the LFE channel, AND the sub receives the bass below your selected crossover frequency from any speakers set to small.

I just wanted to point out that the the above are not absolutes. This is not the way my AVR handles bass mgt. If my mains = large, the sub = yes, and surrounds/center = small. The mains get a full range signal as well as the bass below the crossover from the other channels. The sub gets the LFE only.

--Steve

 

[Mike Sloan]

Both the Denon 5803 and Sunfire Preamp allow you to set mains to large and still have multiple selections for the subwoofer. You can select from 6 Xover points as well as ..LFE only, or a blended LFE with Main information.

 

[Brae]

What I meant is that,which ever channel you select as large,that must carry the full burden of bass of that channel only.

Lewis Besze, now that sounds more like it and I agree, as does Pionner, hehe. Cheers!

 

[Mike Sloan]

BRAE,
You can't go wrong with the M&K! A friend of mine has one that is 10 years old and it is still going strong! Just to clear something up...I am a mercinary when it comes to HT gear...I have no loyalty to any brand..I am just after performance. I do own (2) VTF3's...but I also realize there are better selections to be had. Regarding the M&K 150THX driver configuration one poster was wondering if it is similiar to a passive radiator configuration. It has two 12" drivers mounted in what M&K calls a "push-pull" configuration—that is, one driver mounted in the nonported cabinet conventionally, firing forward, and the other loading into the enclosure, with its rear hanging down toward the floor and its polarity reversed in order to keep the room-radiation in phase.Both drivers are active. http://www.mksound.com/images/speakers/subs/MX-105-125-150-200-350/mx105-125-150-200-

 

[Mike Sloan]

 

[Brae]

Yup, that'd be it.

 

[Brian Bunge]

Brian, a couple of months ago I would have been using that very conclusion, but upon Pioneer telling me the 'dB' on the Master Volume is meaningless I now treat it as such. My only goal in SPL measure a 3dB drop-off what to see how many 'clicks' on the Pioneer Master Volume would be needed to change the SPL by three REAL dB, and that is all.

Brae, my whole point is that your test is faulty regardless of which receiver you're using. Even a receiver whose volume control actually changes in 1dB increments (up or down) will not necessarily give you that same change in dB using the Radio Shack meter. You'd have to spend over $200 for an SPL meter with that type of accuracy.

So again, the receiver being used is irrelavent. The SPL meter being used (and it's accuracy) is the issue here.

 

[Brae]

Brian, I do understand what you are getting at and I do acknowledge the documented 2dB inaccuracy the product's manufacturer clearly states. I cannot imagine that the product is so inaccurate that no one has bothered, including yourself, to measure the magnitude of inaccuracy.
Being that you make speakers and subwoofers, I would expect that you either own or have access to a $200 SPL meter and could easily determine the inaccuracy of the 33-2050 RS SPL for us.