T/S parameters for vintage CTS 8x10 drivers? - Page 2

kringle77 · #21 09-14-2012, 10:31 AM

Will, I actually think the 4x10 with the 32ohms would be 96db and the series paralled 4x10 would be 99db. I asked BFM this question once and I think thats what he said. I was just asking for other peoples thought on it.

Petebass · #22 09-15-2012, 09:24 AM

I have the gear to test it, but given the distance involved it might be cheaper and easier for you to buy the gear for yourself.

http://www.parts-express.com/pe/show...number=390-804

kringle77 · #23 09-19-2012, 04:11 AM

I found what the parameters of the CTS should be when new and ran it in winisd. The low end is almost exactly the same as the berg nv610 driver in the same 24 liter space. The cts is just alittle more low mid boosted, almost the same though, just as my ears suggested. The mids and highs are different though.

oerk · #24 09-19-2012, 05:04 AM

You can measure the TSP yourself with a standard sound card, a few cables, a reference resistor and the software LIMP (included with ARTA).

I'd offer to do it, but, like Petebass, being across the big pond might not help you much.

kringle77 · #25 09-19-2012, 05:42 AM

Well, I don't need to now that I've found the parameters that a fresh CTS should have. I really wanted to know how the low end modeled and it's just what I thought. It hits about 0db at 100hz, about a 1.5db bump centered around 150hz, can't remember the F3 off the top of my head. I've got two weber 10FL 8ohm drivers on order and if they sound the same, I'll be building a new 8x10 for sure.

JGR · #26 09-19-2012, 09:42 AM

Where did you get the parameters? Curious especially about the Xmax.

kringle77 · #27 09-19-2012, 09:47 AM

On here. No xmax but, it's probably between 3mm and 5mm. It doesn't change the curve on winisd though.

Here are the ideal factory specs:

Fs=56 Hz
qms=5.56
qes=0.63
qts=0.56
VAS=54.9 L
Re=27.24
SPL=93.7
Mms=24.6 grams

beans-on-toast · #28 09-19-2012, 10:00 AM

Thanks for finding and posting the specs. For a side-by-side comparison (so to speak), here are the Eminence B810 specs.

kringle77 · #29 09-19-2012, 12:07 PM

The B810 looks pretty comperable to the CTS but, when you model the two in winisd, the cts has less lows and the bump is voiced at around 145hz where as the B810 has more low end and the bump is at around 100hz. This gives the B810 a rather boomy sound in my opinion. The two definitely sound like they are in the same family but again, I prefer the CTS in in every way. I would love to hear a freshly reconed CTS as, I really think my origional is pretty tired. Then again, maybe thats how it is supposed to sound. The B810 has that sharp but narrow 2khz spike that can make it sound clacky when you boost the treble on you amp and it may have a larger dip in the mids than the CTS. The highs are similar though, the CTS having a smaller voice coil produces them alittle more sweetly. For many players, the B810 would be close enough. I myself just put in an order for the weber 10fl drivers which are supposed to be voiced like the CTS. I got the 8 ohm versions so that I can get more sensativity. It takes at least 3 weeks to get them but, in my opinion they are a better investment if you want the old svt sound.

kringle77 · #30 09-19-2012, 12:08 PM

I actually think the eminence alpha is closer to the CTS in some ways and think it would make a better 8x10 cab than the b810's. Better mids, tighter low end, more sensative, Cheaper, lighter.

Buzz Grim · #31 09-19-2012, 07:10 PM

Kringle,
I'd be interested to know what you are you using for Vb / driver when modeling the CTS. Also what F3 did you get? Are you basing your modeling on the volume per driver of the Bergantino 6x10 cab or a vintage SVT? All of your threads have been really informative and I appreciate your efforts.
thanks
Buzz

rpsands · #32 09-19-2012, 07:20 PM

If you took two of the B810s out of the box it'd probably wind up sounding more like the CTS' - more air per woofer - unless they are in separate chambers anyway

(in an 8x10)

Can also experiment with more or less absorbent damping materials.

Buzz Grim · #33 09-19-2012, 07:24 PM

Quote:

Originally Posted by kringle77

I actually think the eminence alpha is closer to the CTS in some ways and think it would make a better 8x10 cab than the b810's. Better mids, tighter low end, more sensative, Cheaper, lighter.

Kringle,
You've probably seen it but on the Bill Fitzmaurice Forum under "SPL Charts" Bill has graphs for 2x10's and 8x10's using the Alpha 10 plus a tweeter. Looks like he's using 1.125 cu ft /driver for the 8x10. I'm assuming this is net volume.

kringle77 · #34 09-19-2012, 07:26 PM

Here is a model of CTS compared to the NV610 driver. both in a 24 liter encloser which is about what each driver gets in both the berg and vintage 8x10 cabs.

The CTS in yellow has an F3 of 79hz and a 1.35db bump at 145hz. The berg in blue has an F3 of 80hz and a 0.82 bump at 155hz.

kringle77 · #35 09-19-2012, 07:32 PM

Yeah, I saw bill's graph and it looks right. You will notice that the bump is centered lower than either of these two drivers. Having the bump centered around 150hz followed by a low end roll off is really part of the sound I like, and it's even better to me in a sealed cab.

Buzz Grim · #36 09-19-2012, 07:40 PM

Part of why your sealed 10 threads have been so interesting for me has been because of the mystery of the bump. When is it a good thing? Where should it be centered? How high and wide should it be? When is it boomy?
You're shedding a lot of light on this.

Buzz Grim · #37 09-19-2012, 07:56 PM

Kringle ,
Thanks for the graphs. I can believe that that is a real F3 for a Vintage Ampeg 8x10. It's funny how people chase extended low end. I guess things got wacky when the low B string came on the scene.

kringle77 · #38 09-19-2012, 08:17 PM

For me, I prefer just what you are seeing on the graph. An F3 of 80hz and about a 1db bump centered around 150hz. Thats exactly my low end profile. I rarely touch my low end eq. In some rooms I might boost the lows just alittle but, hardly ever. The sealed design gives a cab like this alittle bit of compression and a quicker decay than a ported cab which makes it sound even quicker and tighter. Thats my universe right there. I've got some webers on the way that are supposed to sound similar to the CTS. I did try a 32 ohm weber in the past and remember it sounding like a more "fresh" version of the 40 year old CTS I have . If so, Im going to do an 8x10 using them and possibley using a guitar driver in place of one of them. Too soon to talk about it more though.

will33 · #39 09-19-2012, 08:32 PM

Quote:

Originally Posted by kringle77

Will, I actually think the 4x10 with the 32ohms would be 96db and the series paralled 4x10 would be 99db. I asked BFM this question once and I think thats what he said. I was just asking for other peoples thought on it.

As I understand it, amplifiers multiply voltage. If it can swing say some arbitrary number like 40 volts, then it can swing 40 volts. That's what makes the speaker move back and forth, voltage swinging positive to negative and back again.

When you extrapolate it to watts, then things change, but not really. The 40 volts would be more "watts" at 4ohms than it is at 8ohms and very much less at 32 ohms. So, you use the watts to figure how much voltage to swing to put you at 1 watt for testing at all the different impedances.

This would mean you'd have to turn the amp up much higher on the 32 ohm speaker than you do on the 8ohm speaker to get to the same place. I think that is more a deal with amplifier output/speaker power input than it is with actual speaker sensitivity. Not trying to argue about it, more to better understand it.

As always...I am not the expert on this. I stand to be corrected when need be, and if BFM came to a different conclusion, I would certainly defer to that, whatever it is.

Anyway, about the magic hump and high f3's....+1 to it all. There is no question the old SVT's slot themselves in a sweet spot in a mix, and it is specifically because they don't have deep, subwoofy type bass, and strong output in the highbass/lowmids, and a sweet middle/topend that gets a nice musical sound when you push it. I don't know when bass players in general became obsessed with rediculously low, physically impossible, stupidly useless low frequency numbers but the whole thing is an excersize in futility. I think advertising to the uninformed has a lot to do with it. 30hz "reads" like it's more bass than 70hz, even though it's useless. Likewise "400 watts" reads a lot more impressive than "56 volts" or whatever, even though they're the same thing.

Caveat: numbers arbitrarily thrown out there as examples, didn't actually take the time to calculate it all, but folks should get the idea.

kringle77 · #40 09-19-2012, 08:47 PM

Well, to prove my point about sensativity vs ohms I loaded a 2x10 with a pair of 32 ohm mod10's and a cab with one 8 ohm mod10. The single driver 8ohm was louder than the two driver 16ohm. Even though they all have the same sensativity. So, lets say you have a driver that is 95db at 8ohms and one is 32ohms. The 32ohm will sound more like 89db in comparison. In an 8x10 with all drivers in parallel, that would be 98db. The 8ohm drivers win series parallel would be 101db. Thats really important. That said, I've got 8, 8ohm webers on the way. Should be a very efficient cab that hopefully has "the sound".