Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Pete Erskine]

Here is an expansion on my videos about IAS and WB. 
It is divided into 2 - 12 minute videos.

Part 1

Part 2

[Neil White]

Here is an expansion on my videos about IAS and WB. 

Hi Pete,

Thanks for the detailed videos. I think the most interesting thing is the noticeable difference in the equipment profiles between the two pieces of software. The WWB6 profiles seem to be more conservative than the IAS ones. Are these settings something that can be calculated from an equipment's spec sheet?

Neil

[Pete Erskine]

Hi Pete,

Thanks for the detailed videos. I think the most interesting thing is the noticeable difference in the equipment profiles between the two pieces of software. The WWB6 profiles seem to be more conservative than the IAS ones. Are these settings something that can be calculated from an equipment's spec sheet?

Neil

NO, these are arbitrary settings set by the software designer.  Not much to do with eq specs.

[Jens Palm Bacher]

NO, these are arbitrary settings set by the software designer.  Not much to do with eq specs.

Well you could if the specs showed the intermodulation attenuation  etc. It is clear that a Sennheiser 5212 transitter in "low intermod" mode will have better specs than a cheap Shure unit, but it is not easy to read from the spec sheet.

[peter dakin]

great videos Pete.

Can I ask what device your using for scans, does this pump out a file format compatible with WW6 or do you need to convert it?


Cheers

[Henry Cohen]

Well you could if the specs showed the intermodulation attenuation  etc. It is clear that a Sennheiser 5212 transitter in "low intermod" mode will have better specs than a cheap Shure unit, but it is not easy to read from the spec sheet.

Whereas it would be nice to know the IM suppression number, it's really kind of irrelevant: Whereas one device (the transmitter) may not be producing the IM product, another device might be; the preamp in the antenna, the multi-coupler or the receiver front end. The IM software programs are merely pointing out the math of potentially problematic frequencies and in no way negates the need for a "war game" or other walk test.

[Pete Erskine]

Can I ask what device your using for scans, does this pump out a file format compatible with WW6 or do you need to convert it?

Scans are from TTI.  More detail on how I did it can be found at http://www.bestaudio.com/spectrum-analyzer-setups

Normal TTI scans can be used in WB as long as you edit out the Headers using a text file.  All of the scans listed on my website have the headers removed and can be imported into either IAS and WB.

[Jason Glass]

Whereas it would be nice to know the IM suppression number, it's really kind of irrelevant: Whereas one device (the transmitter) may not be producing the IM product, another device might be; the preamp in the antenna, the multi-coupler or the receiver front end. The IM software programs are merely pointing out the math of potentially problematic frequencies and in no way negates the need for a "war game" or other walk test.

With this always in mind, I often adjust the intermod bypass window settings in IAS to generate more usable frequencies in large channel-count coordinations, gradually reducing the bypass bandwidths as required.  It's less risky than completely abandoning triple-beat calculations.  The risk can be further mitigated by setting and adhering to a strict band plan, where like-type equipment is assigned to specific areas of spectrum, with large guard bands between the different types.  This technique is also a reason that I try to stay away from broadband RX antenna amplifiers if possible and use passive higher gain antennas on the front end.

[Henry Cohen]

This is technique is also a reason that I try to stay away from broadband RX antenna amplifiers if possible and use passive higher gain antennas on the front end.

I can't stress enough the validity of this statement. Amplified antennas and other in line preamps cause far more problems than they solve 99% of the time. Their use has limited applications, and not has a band-aid for other inadequate system implementations.

[Neil White]

I can't stress enough the validity of this statement. Amplified antennas and other in line preamps cause far more problems than they solve 99% of the time. Their use has limited applications, and not has a band-aid for other inadequate system implementations.

It is interesting that some manufacturers seem to market active antenna as their recommended product for radio mic receive antenna. Is the correct application to make up for cable losses, not to compensate for rf path loss?

Are there any rules of thumb for how far to keep transmit and receive frequencies separated by in a spectrum band plan?

[ProSoundWeb Community]