Emotiva LPA-1 Impressions by Joe Sixpack

[L.J.]

When you get a BFD, turn it off, then turn it back on while your sub is still on - pictures will fall of the wall!!! More of a depth charge, than a pop...

Yeah, I did that even after you warned me. Scared the @#&$ out of me.

Rich - spend $3 and buy a small 3.5mm cable - the receiver sends a trigger signal to the amp and powers it on when the receiver fires up. Saves power, eliminates pop.

Yep. Rich I had the cable just laying around the house. Do some diggin', you may have one too.

[Rich-n-Texas]

Yeah, I did that even after you warned me. Scared the @#&$ out of me.

Hmmm... Imagine how it would work on my cats!

Yep. Rich I had the cable just laying around the house. Do some diggin', you may have one too.

I probably do, and yes, I'll connect it up.

BTW, I joined Home Theater Shack and have started educating myself on the BFD and accompanying REW s/w. Some of you guys own the recommended DVE test disk IIRC but I may just use the one I got from S&V magazine. I haven't poked around too much over there yet but I wonder what a "Waterfall" diagram looks like?

[kexodusc]

Hmmm... Imagine how it would work on my cats!


I probably do, and yes, I'll connect it up.

BTW, I joined Home Theater Shack and have started educating myself on the BFD and accompanying REW s/w. Some of you guys own the recommended DVE test disk IIRC but I may just use the one I got from S&V magazine. I haven't poked around too much over there yet but I wonder what a "Waterfall" diagram looks like?

I have had mixed results with the REW method. I honestly prefer the ol' test tone and SPL meter method myself. Takes longer and is a more iterative process, but that's just me.
You'll accomplish 90% of the benefit with just a few filters anyway so either way is fine.

[Rich-n-Texas]

And to be sure a BFD would be of benefit to me let me take a minute to refresh eveyone on my LFE situation. If you'll recall, my issue was that in three or four locations where I'd placed my sub, I was hearing very little low frequency sound output during, to a smaller extent movies with surround sound audio but to a larger extent CD's & concert DVD's with DD and/or DTS tracks. It was pointed out that the cause was probably "room modes" and "standing waves" which could be treated with acoustic panels. I think the idea there was to cut down on reflections of the higher frequencies which were masking the LFE. Does that sound about right?

When people mention "peaks and nulls" they're talking about dB level spikes and dips in the low frequency's response curve, correct?

So, where should my focus be... A. Treating the modes and waves, B. The peaks and nulls or C. Both, and will the BFD be the right tool in the event the answer is #C?

(Not shown: D. It's not that simple, and E. I'm waaaaay over-complicating things)

[kexodusc]

And to be sure a BFD would be of benefit to me let me take a minute to refresh eveyone on my LFE situation. If you'll recall, my issue was that in three or four locations where I'd placed my sub, I was hearing very little low frequency sound output during, to a smaller extent movies with surround sound audio but to a larger extent CD's & concert DVD's with DD and/or DTS tracks.

Stop...do you get satisfactory bass with some sources, but not others? If you do, then that suggests a setting problem.

It was pointed out that the cause was probably "room modes" and "standing waves" which could be treated with acoustic panels. I think the idea there was to cut down on reflections of the higher frequencies which were masking the LFE. Does that sound about right?

Errr...no. Room modes/standing waves etc affect bass, but treating the higher frequencies alone will not help the bass very much, not to the extent I believe you are looking for at least.
Two separate treatments.

When people mention "peaks and nulls" they're talking about dB level spikes and dips in the low frequency's response curve, correct?

Yep, peak = loud spike, dip = null (well, actually the dip is probably caused by a null, but not necessarily...let's keep it simple though)

So, where should my focus be... A. Treating the modes and waves, B. The peaks and nulls or C. Both, and will the BFD be the right tool in the event the answer is #C

Room treatments will attack the modes and standing waves - but that will be costly and complex. The BFD just equalizes the frequencies as measured from your listening position so its flat where you sit - this isn't great for higher frequencies, but because of the ear's insensitivity to distortion at low bass frequencies we can easily get away with it using the BFD. It won't solve the peaks and nulls caused by your room's acoustics, but it will flatten them at the listening position. A short cut basically.

[Rich-n-Texas]

Stop...do you get satisfactory bass with some sources, but not others? If you do, then that suggests a setting problem.

Right now, my primary source component (STB notwithstanding) is my DVD changer which is probably also my weakest link. Like GM, I'm listening to all source material with the receiver set to Straight. Now that I have the amp, I get good bass response at my listening position with DVD's containing DTS (which so far have almost all been 48Khz/768Kbps or higher), through my mains. LFE level at the listening position... not so good but if I walk outside of the speaker perimiter (for lack of a better term) LFE is much more audible. When watching standard DVD movies, the LFE at the listening position is marginally better than when listening to a music CD, with LFE (Straight mode 2 channel PCM) being negligable. GM pointed out that the sub is in the picture in this mode.

Errr...no. Room modes/standing waves etc affect bass, but treating the higher frequencies alone will not help the bass very much, not to the extent I believe you are looking for at least.
Two separate treatments.

Commited to memory! (I hope)

Yep, peak = loud spike, dip = null (well, actually the dip is probably caused by a null, but not necessarily...let's keep it simple though)

With that being the case, when I was looking at the sub's response curve during an auto-eq session, it looked pretty nasty. Maybe I should be adjusting the PEQ at the receiver for the sub first, before going any further???

Room treatments will attack the modes and standing waves - but that will be costly and complex. The BFD just equalizes the frequencies as measured from your listening position so its flat where you sit - this isn't great for higher frequencies, but because of the ear's insensitivity to distortion at low bass frequencies we can easily get away with it using the BFD. It won't solve the peaks and nulls caused by your room's acoustics, but it will flatten them at the listening position. A short cut basically.

Well, the panels are already paid for (and here's where I sound like a broken record) so I really should finish and mount them. Try to describe to me in terms I might understand what exactly it is that I'm hearing at my listening position when I have many and extreme dB level peaks & nulls?

[kexodusc]

Right now, my primary source component (STB notwithstanding) is my DVD changer which is probably also my weakest link. Like GM, I'm listening to all source material with the receiver set to Straight. Now that I have the amp, I get good bass response at my listening position with DVD's containing DTS (which so far have almost all been 48Khz/768Kbps or higher), through my mains. LFE level at the listening position... not so good but if I walk outside of the speaker perimiter (for lack of a better term) LFE is much more audible. When watching standard DVD movies, the LFE at the listening position is marginally better than when listening to a music CD, with LFE (Straight mode 2 channel PCM) being negligable. GM pointed out that the sub is in the picture in this mode.

Sounds like a setting/placement problem. What happens if you turn the sub's volume up? Have dabbled with the phase knob?

With that being the case, when I was looking at the sub's response curve during an auto-eq session, it looked pretty nasty. Maybe I should be adjusting the PEQ at the receiver for the sub first, before going any further???

I wouldn't do it. Most auto-eq thingy's don't do a good job at low frequencies.

Well, the panels are already paid for (and here's where I sound like a broken record) so I really should finish and mount them. Try to describe to me in terms I might understand what exactly it is that I'm hearing at my listening position when I have many and extreme dB level peaks & nulls?

Could be a number of things. In my setup, there were a few frequencies of bass that were loud or louder than the average volume, so an explosion would cause some cool boom, but then was a lot of other frequencies that were much lower in volume - earthquakes wouldn't rumble as much, higher bass frequencies were sucked out. More noticeable on music/soundtracks.
If you set the bass you hear to match speaker level, you are probably matching a peak to the eq'd speakers. So the loudest bass is only just as loud as it is supposed to be. Everything below the top of the peak is getting shortchanged.

[Rich-n-Texas]

Sounds like a setting/placement problem. What happens if you turn the sub's volume up? Have dabbled with the phase knob?

I have increased the volume but I can't tell you under which of the conditions I mentioned that I made level changes, and yes, I've toggled the phase switch on the sub's amp with no change.

I wouldn't do it. Most auto-eq thingy's don't do a good job at low frequencies.

Okay. 'Nuff said.

Could be a number of things. In my setup, there were a few frequencies of bass that were loud or louder than the average volume, so an explosion would cause some cool boom, but then was a lot of other frequencies that were much lower in volume - earthquakes wouldn't rumble as much, higher bass frequencies were sucked out. More noticeable on music/soundtracks.

Maybe I should outright buy U-571. That way I'll have a least one constant to work with and as well, be entertained.

If you set the bass you hear to match speaker level, you are probably matching a peak to the eq'd speakers. So the loudest bass is only just as loud as it is supposed to be. Everything below the top of the peak is getting shortchanged.

You just made a key point here I think. I set the sub using a Simpson 899 Sound Level meter and because the needle can deflect as much as, I'd say 3 dB in either direction with the 70 dB mark as a reference (C weighting, slow impulse), it's almost impossible to know if I've set the level correctly.

[f0rge]

i hate rooms.

i get drastically different bass depending on where i stand in my room. luckily i get about 90% in my listening area.

unfortunately for me, having powered towers makes mucking around with placement next to impossible.

[kexodusc]

I have increased the volume but I can't tell you under which of the conditions I mentioned that I made level changes, and yes, I've toggled the phase switch on the sub's amp with no change.

Okay. 'Nuff said.

Maybe I should outright buy U-571. That way I'll have a least one constant to work with and as well, be entertained.

You just made a key point here I think. I set the sub using a Simpson 899 Sound Level meter and because the needle can deflect as much as, I'd say 3 dB in either direction with the 70 dB mark as a reference (C weighting, slow impulse), it's almost impossible to know if I've set the level correctly.

Rich, your SPL meter could be giving you bad readings too - depending on the low frequency used, the SPL meter may cease to provide accurate readings. The ever popular radio shack SPL meters are great because there are correction value tables that people have been maintaining for years that compensate the for the low frequency inaccuracies.

So 70 dB could really be 62 dB, or it could be 74 dB? At least with the Radio Shack meters you can apply the corrections to get a closer number. With other SPL meters, it's best to know the accuracy and frequency limits.

As far as bouncing needles - don't worry about that...if you can eyeball the same general area, you're pretty darn close.

[pixelthis]

Heres an idea, rich...unplug the sub.
B&W speakers are famous for their bass.
I still havent gotten a plate amp for my sub, and dont miss it, really.
DECENT stereo bass is really quite nice.
SOMETIMES YOU CAN GET TOO MUCH OF A GOOD THING.
I dont miss trying to configure a cantankerous sub to give good sound, instead of booming
and distortion

[Rich-n-Texas]

Heres an idea, rich...unplug the sub.

Turn the sub into an end table? Or plant stand? Naaaa.

B&W speakers are famous for their bass.

Now that I've got something that can drive them, I agree.

I still havent gotten a plate amp for my sub, and dont miss it, really.
DECENT stereo bass is really quite nice.

Yeah but I'm using my speakers in a surround sound environment a good 40% of the time. The flick U-571 should be in the mailbox when I get home tonite and I'm going to do some listening tests with it.

SOMETIMES YOU CAN GET TOO MUCH OF A GOOD THING.
I dont miss trying to configure a cantankerous sub to give good sound, instead of booming
and distortion

When I get my LFE response tweaked to where I can knock the assclown who comes by my house in his pickup truck with the sub so loud it rattles my coffee mugs, off the road then I'll be happy.

[Rich-n-Texas]

Rich, your SPL meter could be giving you bad readings too - depending on the low frequency used, the SPL meter may cease to provide accurate readings.

WHAT?!?!?
I've only used the tone generated by the receiver up to this point. I haven't really played around with the test disk I have but I guess that should be the next order of business. I also have the option of taking home a calibrated frequency generator. An engineer and I figured out the correct line voltage (1.2 volts IIRC) to inject into the line-in at the sub.

The ever popular radio shack SPL meters are great because there are correction value tables that people have been maintaining for years that compensate the for the low frequency inaccuracies.

Well, the impression I got over at The Shack was that even with the availability of the cal files, the complaint was that no two RS SPL meters have the same inaccuracies.

So 70 dB could really be 62 dB, or it could be 74 dB? At least with the Radio Shack meters you can apply the corrections to get a closer number. With other SPL meters, it's best to know the accuracy and frequency limits.

No, the overall range was 6 dB, about 3dB on either side of the 70 dB mark. That's just from memory though and again, with using the receiver's tone generator.

As far as bouncing needles - don't worry about that...if you can eyeball the same general area, you're pretty darn close.

Don't know what you mean here. General area = the 70 dB mark?

[kexodusc]

WHAT?!?!?
I've only used the tone generated by the receiver up to this point. I haven't really played around with the test disk I have but I guess that should be the next order of business. I also have the option of taking home a calibrated frequency generator. An engineer and I figured out the correct line voltage (1.2 volts IIRC) to inject into the line-in at the sub.

Test disc and SPL meter is fine, but a frequency generator might be fun to play with.

Well, the impression I got over at The Shack was that even with the availability of the cal files, the complaint was that no two RS SPL meters have the same inaccuracies.

No two SPL meters anywhere will measure perfectly the same, but the Rat Shack meters are consistently inconsistent in each production batch. They'll have the same over reporting/under reporting frequencies in other words, give or take a bit. Close enough. I have a Galaxy Audio SPL meter that costs a few hundred bucks - it's super accurate, and my Rat Shack meter + correction values are very close with the exception of between 110-120 Hz. 1-2 dB tops. Your SPL meter could be fine, we just don't know.

No, the overall range was 6 dB, about 3dB on either side of the 70 dB mark. That's just from memory though and again, with using the receiver's tone generator.

I meant that the RS meter might read 70 dB when really it's only 64 dB. Not the range of the needle.

Don't know what you mean here. General area = the 70 dB mark?

Disregard that comment, think I misunderstood what you were saying earlier...I don't want to add to the confusion.

[basite]

Heres an idea, rich...unplug the sub.
B&W speakers are famous for their bass.
I still havent gotten a plate amp for my sub, and dont miss it, really.
DECENT stereo bass is really quite nice.
SOMETIMES YOU CAN GET TOO MUCH OF A GOOD THING.
I dont miss trying to configure a cantankerous sub to give good sound, instead of booming
and distortion

maybe you could learn how to set the sub up correctly, right?

even though B&W is 'famous for their bass' (I prefer other bass, personally...), they CAN NOT & WILL NOT be able to give the full experience of a big, heavy exlosion (see transformers or so) in H/T. that's why you need a sub.

saying a sub brings boominess & disortion & too much bass is pure nonsense. This would apply to inexperienced people, who don't know how to properly set up a sub.


Keep them spinning,
Bert.

[Rich-n-Texas]

Feeling a little chippy today Bert?

[pixelthis]

Turn the sub into an end table? Or plant stand? Naaaa.

Now that I've got something that can drive them, I agree.

Yeah but I'm using my speakers in a surround sound environment a good 40% of the time. The flick U-571 should be in the mailbox when I get home tonite and I'm going to do some listening tests with it.

When I get my LFE response tweaked to where I can knock the assclown who comes by my house in his pickup truck with the sub so loud it rattles my coffee mugs, off the road then I'll be happy.

He's MAD I tell you...MAD

[Rich-n-Texas]

Imagine how many friends you'd make pix if, instead of saying anything you only posted pictures.

[pixelthis]

Imagine how many friends you'd make pix if, instead of saying anything you only posted pictures.

You mean like you?

[f0rge]

very niiice, how much?

[pixelthis]

very niiice, how much?

For just one or the matched set ?
(the one in the middle is free)

[GMichael]

For just one or the matched set ?
(the one in the middle is free)

What are you doing out in the middle of the day? Don't you need your sleep?

[Rich-n-Texas]

Yeah pix, "wake up and go to sleep!"

[GMichael]

My dad had a nurse who used to wake him up at 3 AM every night to give him a sleeping pill.

[basite]

My dad had a nurse who used to wake him up at 3 AM every night to give him a sleeping pill.

a good example of it