Speakerplans.com Homepage
Forum Home Forum Home > General > Electro Frying Forum
  New Posts New Posts RSS Feed - REW + Home Theater Setup Mic
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

REW + Home Theater Setup Mic
 Post Reply Post Reply
Author
Message
  Topic Search Topic Search  Topic Options Topic Options
120hz View Drop Down
Registered User
Registered User


Joined: 23 August 2017
Location: Devon
Status: Offline
Points: 31 		Post Options Post Options   Thanks (0) Thanks(0)   Quote 120hz Quote  Post ReplyReply Direct Link To This Post Topic: REW + Home Theater Setup Mic
    Posted: 04 March 2018 at 9:16pm
Anyone know if a HT mic would be suitable for taking measurements with you know like the one you get with a Yamaha AV receiver?, I have been using the laptops built in mic but I get the impression it might be a little bit dodgy...

Also would anyone be interested in the graphs if the HT mic is more accurate, I have 2 Cubo 18 loaded with 18lw24000, 2 Cubo 18 loaded with QTX 450w rms drivers (not actually too bad) and 2 Cubo 15 kick loaded with some eminence beta I think? Wonder how much of a difference spending £200.00 extra per driver can make at low to medium levels...
Back to Top
Conanski View Drop Down
Old Croc
Old Croc
Avatar

Joined: 26 January 2006
Location: Ottawa, Canada
Status: Offline
Points: 2757 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Conanski Quote  Post ReplyReply Direct Link To This Post Posted: 04 March 2018 at 9:51pm
Originally posted by 120hz 120hz wrote:

Anyone know if a HT mic would be suitable for taking measurements with you know like the one you get with a Yamaha AV receiver?, I have been using the laptops built in mic but I get the impression it might be a little bit dodgy...
A little dodgy!! That would be the understatement of the decade. The HT mic has possibilities but I suspect it is a powered condenser mic just like a real measurement mic so it won't work too well just plugged directly into the laptop, you need to supply some phantom power which could be 5-10v.. hard to know unless you can find it in the specs. Failing this the next best option would be a USB test mic, this gets around the phantom power problem and also bypasses the laptop soundcard which is always a hugh pile of dung.

Originally posted by 120hz 120hz wrote:

Also would anyone be interested in the graphs if the HT mic is more accurate, I have 2 Cubo 18 loaded with 18lw24000, 2 Cubo 18 loaded with QTX 450w rms drivers (not actually too bad) and 2 Cubo 15 kick loaded with some eminence beta I think? Wonder how much of a difference spending £200.00 extra per driver can make at low to medium levels...
Graphs are always good. Be sure to generate calibration files for the mic and whatever is between it and the recording software, otherwise the graphs you generate don't represent anything meaningful.


Edited by Conanski - 04 March 2018 at 9:55pm
Back to Top
bitSmasher View Drop Down
Old Croc
Old Croc
Avatar

Joined: 23 June 2012
Location: Melbourne
Status: Offline
Points: 2302 		Post Options Post Options   Thanks (0) Thanks(0)   Quote bitSmasher Quote  Post ReplyReply Direct Link To This Post Posted: 05 March 2018 at 11:47am
MiniDSP UMik - REW can upload the calibration file, runs on USB and is affordable.

I've also plugged that mic in to an iPad and Samsung phone (via specific cables) and they both worked.
https://www.instagram.com/batteryacidsoundsystem/
Back to Top
bitSmasher View Drop Down
Old Croc
Old Croc
Avatar

Joined: 23 June 2012
Location: Melbourne
Status: Offline
Points: 2302 		Post Options Post Options   Thanks (0) Thanks(0)   Quote bitSmasher Quote  Post ReplyReply Direct Link To This Post Posted: 05 March 2018 at 11:49am
Also just re-read the question and I have used a similar mic with a laptop - they will put a few volts phantom on the mic input
https://www.instagram.com/batteryacidsoundsystem/
Back to Top
120hz View Drop Down
Registered User
Registered User


Joined: 23 August 2017
Location: Devon
Status: Offline
Points: 31 		Post Options Post Options   Thanks (0) Thanks(0)   Quote 120hz Quote  Post ReplyReply Direct Link To This Post Posted: 05 March 2018 at 1:04pm
Regarding the phantom volts will this skew the measurements, is there anything I can do to help with the accuracy, perform sweeps at a higher spl for example?

I just don't really want to buy a measurement microphone when I could put the money towards another amplifier

Edit: the mic only has a mono 3.5mm jack on it anyway so if it did need power how would I provide it?

Edited by 120hz - 05 March 2018 at 1:06pm
Back to Top
MattStolton View Drop Down
Old Croc
Old Croc
Avatar

Joined: 04 September 2010
Location: Walthamstow
Status: Offline
Points: 4207 		Post Options Post Options   Thanks (0) Thanks(0)   Quote MattStolton Quote  Post ReplyReply Direct Link To This Post Posted: 05 March 2018 at 4:09pm
The danger is that the mic doesn't have a flat response.

Your AV amp will have the mics response built in as a correction to any measurement (at least I hope it would!), so any rise or fall in the mics pick-up, will be offset by some corrective EQ in the amp mic input. They may well have engineereed it to have a drop in response at certain frequencies, so when the AV amp "corrects" the speaker output, it may add some form of designed "smiley face" type EQ, to "sweeten" the sound.

Very expensive mics will either be flat (ish) or include a measured response, so you can tell your measuring system what the mic does, so the system subtracts that to give a flat pickup response. A mic that comes for free with a £400 AV amp will not be flat?

Still worth a try, as better than nothing, but will not be flat out of the box. Perhaps a scour of the internet may reveal a generic response plot for that mic, but yours may be at the extreme of tolerance of manufacture.

Without testing cert, which is money, you will not know.

Most laptop "mic" sockets will provide some small VDC to phantom power electret pickups in headsets, usually around 5V DC across Tip or Ring, relative to screen.
Matt Stolton - Technical Director (!!!) - Wilding Sound Ltd
"Sparkius metiretur vestra" - "Meter Your Mains"
Back to Top
120hz View Drop Down
Registered User
Registered User


Joined: 23 August 2017
Location: Devon
Status: Offline
Points: 31 		Post Options Post Options   Thanks (0) Thanks(0)   Quote 120hz Quote  Post ReplyReply Direct Link To This Post Posted: 07 March 2018 at 10:08pm
Ok I think I understand, I will try to do some proper testing tomorrow, just from messing about the mic does seem to be very quiet and does not pick up the sweeps quite how it should. So far this has just been fixed by doing the sweeps a little louder much to my neighbors annoyance. There are no markings at all on the mic, all I know is that it came with a Denon receiver I bought a couple of years ago which isn't much help.

PS what's everyone's opinions on Bi-amping, I have some completely unbranded debadged speakers that seem to sound pretty good, the crossover however looks like it's the weak point, just worried it might go bang. The tops are driven off a 4 channel 250w p/ch amp bridged into 2 channels.

Thanks
Back to Top
 Post Reply Post Reply

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.08
Copyright ©2001-2026 Web Wiz Ltd.