REW For Simple Desktop Speakers?

[HarmonicTHD]

I did not increase the buffer size since I'm no longer seeing the drop - a conundrum.

Great.

 

[wacomme]

Happy to see you make progress.

At these frequencies sound is not directional and angle does not matter. What matter is positioning in space and proximity to walls.

REW has a room simulator built in. It can give you hints what dip is caused by which position. However in the end there will always be a compromise. Again only sub(s) positioned strategically can give you a near perfect low frequency response.

What do you mean by, "At these frequencies sound is not directional and angle does not matter?"

I will give the room simulator a try. I suppose I could do some monitor re-positioning, but I'm not sure what to try. I hope the REW simulation will provide a few suggestions.

I did generate EQ files from today's measurements. It does improve the sound.

 

[wacomme]

Great.

Yes, but from what happened earlier I have a new SMSL dac coming next week.

 

[HarmonicTHD]

What do you mean by, "At these frequencies sound is not directional and angle does not matter?"

I will give the room simulator a try. I suppose I could do some monitor re-positioning, but I'm not sure what to try. I hope the REW simulation will provide a few suggestions.

I did generate EQ files from today's measurements. It does improve the sound.

Your question was why one speaker shows different low frequency response and assumed it was due to the angle. My answer is that it is not the angle as at low frequency you can angle the speaker anyway you want and it will (hardly) make a difference as the low frequency sound is radiating in all directions equally (to put it simply). Different for higher frequencies though. See the spinoramas of Amir’s measurements for the exact radiation pattern of your particular speaker.

 

[wacomme]

Thanks for your help. I'm now just sitting back and enjoying:

Thank you.

I know I'll make more adjustments in the coming weeks, but I think I'm on my way. Thanks everyone!!!!

 

[wacomme]

I did more REW measurements today and I'm now fairly convinced my SMSL D0100 dac has a right channel problem. The measurement graph is an average of three measurements per channel. Instead of a 5kHz dropoff, I now have a 10kHz dropoff on the right channel. What's also odd, when I was making the measurements, I had to turn off and turn back on the dac to get any pink noise sound for each of the three measurements. This was not the situation when measuring the left channel; I didn't have to turn off and back on the dac for the pink measurement noise.

My replacement dac arrives Thursday. I'll be testing it right away.

 

[wacomme]

Happy to see you make progress.

At these frequencies sound is not directional and angle does not matter. What matter is positioning in space and proximity to walls.

REW has a room simulator built in. It can give you hints what dip is caused by which position. However in the end there will always be a compromise. Again only sub(s) positioned strategically can give you a near perfect low frequency response.

What would I need if I were to buy a subwoofer to improve my low frequency response? I have REW and the ability to generate multi-channel FIR filtering, so hopefully I have the means for dsp. Right now my Adam T5V speakers are connected with balanced cables to a L50 amp and DO100 dac, which in turn are connected to my Mac computer via usb. Would I need a preamp, or an ASV? If so, what relatively low cost options are available to me? Could I vastly improve the low end with a $100 sub and a cheap preamp or ASV? I love the sound now, but if I could get a flat frequency response for little money, then nirvana! Besides, it’s a bit of a challenge.

 

[HarmonicTHD]

What would I need if I were to buy a subwoofer to improve my low frequency response? I have REW and the ability to generate multi-channel FIR filtering, so hopefully I have the means for dsp. Right now my Adam T5V speakers are connected with balanced cables to a L50 amp and DO100 dac, which in turn are connected to my Mac computer via usb. Would I need a preamp, or an ASV? If so, what relatively low cost options are available to me? Could I vastly improve the low end with a $100 sub and a cheap preamp or ASV? I love the sound now, but if I could get a flat frequency response for little money, then nirvana! Besides, it’s a bit of a challenge.

For sub integration you need something which controls the signals going to sub and main speaker. Currently you are doing this via SW EQ

The following options come to mind
a) MiniDSP. Here you would set the EQ in the device and not via SW EQ. Not too expensive and small.
b) AVR. Overkill for your desktop application.
c) MultiChannel Audio Interface. Here you need an Audio Interface which can do multichannel and most importantly where you have drivers or software to send different signals from your SW EQ to. Honestly I don’t know if that exists. I have an audio interface (Focusrite 4i4) which can do multichannel and there are more, but I am not certain if there is an interface to a SW EQ.

 

[czt]

Or
d) You use the (studio) subwoofer internal LP/HP filters/crossover for "bass management". And of course your microphone for the integration measurements to find the optimal placement and settings (level, crossover, phase).

 

[wacomme]

Or
d) You use the (studio) subwoofer internal LP/HP filters/crossover for "bass management". And of course your microphone for the integration measurements to find the optimal placement and settings (level, crossover, phase).

OK, but how do I connect the subwoofer (like this one), to my system? What's the interface?

 

[wacomme]

For sub integration you need something which controls the signals going to sub and main speaker. Currently you are doing this via SW EQ

The following options come to mind
a) MiniDSP. Here you would set the EQ in the device and not via SW EQ. Not too expensive and small.
b) AVR. Overkill for your desktop application.
c) MultiChannel Audio Interface. Here you need an Audio Interface which can do multichannel and most importantly where you have drivers or software to send different signals from your SW EQ to. Honestly I don’t know if that exists. I have an audio interface (Focusrite 4i4) which can do multichannel and there are more, but I am not certain if there is an interface to a SW EQ.

I'd rather not go the route of a miniDSP (or Dirac Live), mostly because I want to keep costs low, but also because I'd like to get it to work using REW (free) for measuring and Hang Loose Convoluter (HLC) for applying FIR filters to my system.

Should I get a refund on my replacement SMSL DO100 (arriving today) and get a Motu M4 instead? It's not as good a dac as the DO100, but I'm not sure I'd hear the difference, and I think the Motu M4 would allow me to connect a sub and EQ the monitors and sub. Is there a better solution?

 

[czt]

OK, but how do I connect the subwoofer (like this one), to my system? What's the interface?

What you already have for the full range monitors.

 

[wacomme]

What you already have for the full range monitors.

Yes. That's a distinct possibility. However, I'm still wondering if I can smooth out the low frequencies with a sub.

 

[czt]

Yes. That's a distinct possibility. However, I'm still wondering if I can smooth out the low frequencies with a sub.

Absolutely possible with careful integration and then EQ. But a sub will be wife-compatible?

 

[wacomme]

Absolutely possible with careful integration and then EQ. But a sub will be wife-compatible?

My wife is accepting my Adam T5V monitors. Actually, she's said nothing about them, which qualifies as being acceptable. With my desk at an angle to the wall, I have space behind the desk (in the corner is my only viable location - which generally is the best location) to put a sub - so out of sight, out of mind.

 

[JohnPM]

Regarding the 5 kHz drop-off, some DACs (with ESS chips?) have an auto-mute function that activates if there is no signal on the left channel for a few seconds, makes it difficult to use them for individual channel measurements.

 

[wacomme]

Regarding the 5 kHz drop-off, some DACs (with ESS chips?) have an auto-mute function that activates if there is no signal on the left channel for a few seconds, makes it difficult to use them for individual channel measurements.

That’s good to know, and I’ll keep that in mind when I do some REW measurements today with the replacement dac. However, if that’s the situation, perhaps I need a different dac than the DO100. I want individual channel measurements. Is there any way to know if the SMSL DO100 has that auto-mute function other than via REW measurement testing?

 

[JohnPM]

Play any test signal on the right channel only, if it stops after a few seconds that would look like the mute behaviour. You could just send the test signal to L+R all the time and unplug the connection to the speaker not being measured, though that seems a faff. Did you post about having another DAC earlier in the thread? Could use that or use the built-in audio of the Mac, don't need anything special for acoustic measurements.

 

[wacomme]

Play any test signal on the right channel only, if it stops after a few seconds that would look like the mute behaviour. You could just send the test signal to L+R all the time and unplug the connection to the speaker not being measured, though that seems a faff. Did you post about having another DAC earlier in the thread? Could use that or use the built-in audio of the Mac, don't need anything special for acoustic measurements.

I'm using REW for EQ measuring. When measuring the right speaker I got a steep drop at 5kHz. Another measurement it was at 10kHz. This was for R channel only. The L channel didn't have this issue. Yesterday I received a dac (SMSL DO100) replacement. I'll EQ measure my stereo monitors again today using REW - separate measurements for L/R channels. I'm hoping I don't have the steep drop issue with the new dac. If I do, then perhaps I have an auto-mute issue, not a R channel dac problem. I'll know later today.

 

[wacomme]

Play any test signal on the right channel only, if it stops after a few seconds that would look like the mute behaviour. You could just send the test signal to L+R all the time and unplug the connection to the speaker not being measured, though that seems a faff. Did you post about having another DAC earlier in the thread? Could use that or use the built-in audio of the Mac, don't need anything special for acoustic measurements.

I've had issues with my DO100. When making REW measurements for EQ I was getting sudden dropouts around 5kHz. So, I was able to replace the dac. Unfortunately, the replacement has the same issues.

With my replacement dac - same R channel cutoff issues - I was able to circumvent the cutoff (turn the dac off and back on for each measurement) and update the EQ. I don't know what to make of the R channel issue. It seems to be type of protective cutoff - though only on the R channel. When doing a second REW measurement without turning the dac off and back on, I get a sudden audible snap in the sound 2/3 of the way through the measurement, resulting in a pronounced frequency drop around 5kHz. Both dacs do this identically. Also, when sending full range pink noise to the R channel via REW, I get about a second of sound and then nothing. Only when I turn off and back on the dac can I repeat that second of sound. The L channel does not have this problem. It plays the pink noise just fine.

What is happening? Should I return and dac and get a different dac altogether? Is this problem really NOT a problem - just a problem (with work-arounds) when measuring frequency output? Do other dacs have the same issue? Is it because I'm measuring one monitor at a time, with no sound coming from the L channel, and therefore the dac shuts down (doesn't turn off, but stops functioning)? It's all so very strange.

My measurements and resulting EQ are solid and sound good - just as long as I restart the dac for every R channel REW measurement. BTW - it's not the monitors; I switched the monitors and had the same R channel problem.

And if I decide to replace my DO100 with something else, what do you suggest (need balanced connections)?