Why so little love for 30IPS?

Han

New member
I dunno if you guys have been able to listen to a fine two inch and actually it depends on the machine itself as well, but my Otari sounds significantly better at 30ips and for jazz recording etc I prefer 30ips, really. :D

But otoh, bands choose for 15 because of the cost of tape.
 
Yes it will be significantly better but not hugely better, And by better, it will be mainly some improvement in headroom.

When people start saying things like 30ips is better for jazz , what can anybody say? So if the same instruments were being played by classical musos, not jazz musos the benefits of 30ips wouldnt apply?

Whoever heard of a tape speed having a preference for jazz improvisation? So which tape speed is best for hip hop, or country and western, or Yiddish folk music played on a two stringed dulcimer with strings made out of a mountain goat's intestines? Which tape speed again?

Anyway I like your sense of humour.

A fine two inch. 16 tracks on two inch just translates to a certain track width and that's all that matters. The tracks dont interact with each other in any way so the track count is irrelevent, just the track width and tape speed. Cassette width tape with the same track width would give the same sound. Tim
 

ofajen

Daddy-O Daddy-O Baby
Hi,

I am curious about it, because mostly I see it derided both here and elsewhere.

I know the "shortcomings":

More headwear.
Lots more tape.
Low-FQ roll-off compared to 15IPS

I know most machines don't have it, but I have heard from folks who do, who still don't find it a good option.

Last year, I bought a Studer 807 Mk2 in fantastic shape on EBay, and one of the reasons I chose that one was the 30IPS option (it has 7.5 and 15 as well.)

I just find that on things like acoustic guitar, GP9 at that speed just is...amazing. The air. The headroom. I can hammer it if I want or just back off and let the natural dynamics play out, with next to no noise and no Dolby.

I am not saying to use it for everything; the thickening at 15IPS gives the right rock 'whomp', but if that is not what you need, 30 is as pretty as analog can get, in my opinion.

Anyone else using it? Any opinions?

Best,
C.

I pretty much agree. I do like 30 ips, especially on quieter, more detailed music without heavy bass, but often I simply don't want use up that much tape. When I had an M-79 2-track I would sometimes mix 1/4" at 30 ips, but 15 ips IEC1 is a pretty good choice and how I've done the majority of mixes.

Right now my M-23 still has the original rim drive that runs 7.5/15 ips. I have the parts to convert to belt drive at 15/30, but no immediate plans to do so, assuming the transport continues to work well. I'd have to replace some trimmer caps to get the eq cards right, too. So it'll pretty much be 15 ips for at least a while.

Cheers,

Otto
 

ofajen

Daddy-O Daddy-O Baby
I pretty much agree. I do like 30 ips, especially on quieter, more detailed music without heavy bass, but often I simply don't want use up that much tape. When I had an M-79 2-track I would sometimes mix 1/4" at 30 ips, but 15 ips IEC1 is a pretty good choice and how I've done the majority of mixes.

Perhaps I should mention that some of the preference for the sound of 30 ips over 15 ips has to do with the choice of EQ standard.

15 ips NAB is the EQ standard that gives 15 ips a bad name, IMO. Designed by Ampex for the tapes and machines of its time (1953), it requires a big record bass boost that modern machines using modern tapes don't need. This is a problem, since it significantly reduces low-end headroom on the total system. The end result, on organ or other bass-heavy music, is a tendency for low-frequency intermodulation distortion. Also, the NAB curve on the high end leaves more headroom than is needed for modern machines and modern tapes, resulting in reduced S/N and more noticeable hiss.

15 ips IEC1 has no record bass boost, less intermodulation distortion, better high end S/N and less prominent hiss. Those features, combined with the low end advantages of 15 ips and lower tape cost than 30 ips make it an appealling choice. Jay McKnight (MRL) even offers his Studio Master or "SM" EQ for 15 ips that boosts the high frequency flux another 3 dB above the levels of the IEC1 standard, but I have not used that standard.

Since the fall of 1970, there is only one EQ standard for 30 ips and it is known as either AES or IEC2.** It is wavelength identical to 15 ips IEC1 and the same calibration tape can be used for either speed without level compensation at any frequency, but merely by recognizing that frequencies are doubled at 30 ips. 30 ips AES also lacks the shortcomings of 15 ips NAB (bass distortion and greater hiss) and so may also be an appealling choice compared to NAB. However, the bass roll off will be raised an octave compared to 15 ips and that may be a nuisance recording music with strong low end parts.

Cheers,

Otto

** The IEC standard does include an IEC1 standard at 30 ips which is never used for new recordings and is only used for 30 ips 1/4" mono recordings made in Europe prior to 1955. Oddly enough, I've been listening to such recordings a lot lately, albeit on CD, since I've been listening to recordings of Debussy piano work recorded in Europe by Walter Gieseking in the early 1950s.
 
Just to add, Otto, the reason for the NAB LF record boost and playback cut was because hum in playback circuits of the day was a potential problem and they addressed it by boosting LF above the hum when recording, but which lead to the IM distortion risks you mentioned.


Cheers Tim
 

3348HRGUY

New member
Perhaps I should mention that some of the preference for the sound of 30 ips over 15 ips has to do with the choice of EQ standard.

15 ips NAB is the EQ standard that gives 15 ips a bad name, IMO. Designed by Ampex for the tapes and machines of its time (1953), it requires a big record bass boost that modern machines using modern tapes don't need. This is a problem, since it significantly reduces low-end headroom on the total system. The end result, on organ or other bass-heavy music, is a tendency for low-frequency intermodulation distortion. Also, the NAB curve on the high end leaves more headroom than is needed for modern machines and modern tapes, resulting in reduced S/N and more noticeable hiss.

15 ips IEC1 has no record bass boost, less intermodulation distortion, better high end S/N and less prominent hiss. Those features, combined with the low end advantages of 15 ips and lower tape cost than 30 ips make it an appealling choice. Jay McKnight (MRL) even offers his Studio Master or "SM" EQ for 15 ips that boosts the high frequency flux another 3 dB above the levels of the IEC1 standard, but I have not used that standard.

Since the fall of 1970, there is only one EQ standard for 30 ips and it is known as either AES or IEC2.** It is wavelength identical to 15 ips IEC1 and the same calibration tape can be used for either speed without level compensation at any frequency, but merely by recognizing that frequencies are doubled at 30 ips. 30 ips AES also lacks the shortcomings of 15 ips NAB (bass distortion and greater hiss) and so may also be an appealling choice compared to NAB. However, the bass roll off will be raised an octave compared to 15 ips and that may be a nuisance recording music with strong low end parts.

Cheers,

Otto

** The IEC standard does include an IEC1 standard at 30 ips which is never used for new recordings and is only used for 30 ips 1/4" mono recordings made in Europe prior to 1955. Oddly enough, I've been listening to such recordings a lot lately, albeit on CD, since I've been listening to recordings of Debussy piano work recorded in Europe by Walter Gieseking in the early 1950s.
No argument there. I used to do mostly: DASH, Pro Digi and ADAT transfers. And of course plenty of analog transfers. We had to turn down a client once because our studio did not have a Stephens 2 inch 40 track. I believe that is the 811D. I think.

We had: 2 Otari MX-80s with the 32 track head stack, the 2 inch head stack with the 1 inch 12 track playback head for playing back tapes made on the Scully 284-12; a Tascam 1 inch 16 track recorder, a half inch 8 track, a Studer A800 Mark 2, 1 inch 8 track, 3 Studer 827s, 3 JDF Magnetics 2 inch 8 track head stacks (we usually mounted those on the 827s), an restored Ampex 300 -4 half inch 4 track, 2 Sony 3348HR, 2 Mistubusihi X-850s, a dozen ADATS......but, no 2 inch 40.
Fun! I am retired now at 62 because of my poor vision.

Your discussion reminds me of a talk I had with my Uncle Jack awhile back. He used to be an audio engineer as far back as 1967. He is still going at 73! We were arguing over the merits of 15 and 30 ips. Apparently it used to be the thing to run your 2 inch 16 track at 30 ips. Back in 1973 that would get you 69 db 'A' weighted signal to noise ratio. I asked, "What about Dolby A?"
I myself have transfered lots of 1 inch 8, 2 inch 16/24/32 track tapes encoded with Dolby A. A few with DBX Type 1. Mostly between 1970 - 1986. I assumed Dolby A was standard by the early seventies. Certainly in big Pro studios. By 1971, 20 studios in London, England were using 2 inch 16 track with Dolby A. Uncle told me, "Not every engineer liked NR. I never liked the way Dolby A sounded on 2 inch."

Question. Wouldn't running your tape at 30 ips castrate your bottom end with the 2 inch 24 track machines of old? for example the Otari MTR90

@ 15 ips.....30 - 20 000 +-2db
@ 30 ips.....50 - 25 000 +-2db
Record / reproduce.

I have transfered a few 2 inch 24 track tapes made at 30 ips and the low end is just not the same. Still sounds good.. Is it worth spending double the price in tape just to get another 2 db of signal to noise ratio? The MTR90 like other 2 inch 24 tracks of the the period could pull 66 db unweighted (69 db 'A' weighted) without a problem at 15 ips. This is extremely quiet already. Distortion is lower of course and smoother top endnat 30 ips, but the MTR90 is
60 - 18 000 hz +- 1db at 15 ips Record/reproduce.
This is a pretty linear top end already.
 

Papanate

Active member
Hi,

I am curious about it, because mostly I see it derided both here and elsewhere.

I know the "shortcomings":

More headwear.
Lots more tape.
Low-FQ roll-off compared to 15IPS

I know most machines don't have it, but I have heard from folks who do, who still don't find it a good option.

Last year, I bought a Studer 807 Mk2 in fantastic shape on EBay, and one of the reasons I chose that one was the 30IPS option (it has 7.5 and 15 as well.)

I just find that on things like acoustic guitar, GP9 at that speed just is...amazing. The air. The headroom. I can hammer it if I want or just back off and let the natural dynamics play out, with next to no noise and no Dolby.

I am not saying to use it for everything; the thickening at 15IPS gives the right rock 'whomp', but if that is not what you need, 30 is as pretty as analog can get, in my opinion.

Anyone else using it? Any opinions?

Best,
C.
Guitars and Bass and Keyboards - 15ips - Vocals and Drums 30 ips - it sounds better that way.
 
I have adjusted Tascam machines that were 30 IPS and there is no reason to use that much tape. Yes you can get response 40Hz to 30KHz plus or minus 1dB but I got a 15 IPS deck with SM900 to go to 50KHz inside plus or minus 2dB whats the point? Once you get past 20KHz the rest is all dream land. If you are recording at +9dB then you will need the headroom but most people don't need it as much as they think they do. Practice on the talent end and then let the recording companies buy the fancy equipment.
 
Low end is one reason a 15 IPS deck is better than a 30 IPS. Unless you are recording pipe organs that can go below 50 Hz then there is not that much down that low.
Some low end can be enhanced by larger coupling caps in the audio path. There is a reason that they made it this way and if it was necessary they would have made the low end more extended.
 

Papanate

Active member
No love for 30ips? Since when? Now I imagine with all the lower budget machines running 30ips is pretty sterile versus 15ips which imparts more lift and a solid bass
- but a 30 ips like the Studer A800 MK III 24 trk - that's a different story.
 
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