New sub need help designing enclosure.

[Hdale85]

I just orderd an OEM10 from TC sounds and 2 of the matching PR's. I tried to get help on their boards and doesn't seem to be working out so well. I'm running it with a Crown XTI 1000. Here are the parameters for the sub

TSP's

Qts 0.357
Qes 0.400
Qms 3.35
Fs 30Hz
Res 3.11 ohms
Ls 4.0 mH
Lp 6.26 mH
Rp 9.9 ohms
Dia 208mm
Vas 19.3 liters
Mms 224 grams
Cms 119 um/N
BL 18.35Tm
Spl 83.3dB

They don't list SD or LE though. Also they don't seem to have the T/S's for the PR's not sure if its needed? It's a 10" driver same for the PR's. I'm running linux and can't seem to get unibox to work in openoffice correctly. I would like the PR's tuned to 20hz so I'm trying to find out how big the enclosure needs to be (I'm guessing around .5 cu ft) and how much weight to add to the PR's.

Thanks in advance!

In case you need any of this these are the specs.

OEM overstock TC-10.
Lightweight Honeycomb glass fiber cone
1" tall NBR surround
28mm xmax
190 ounce motor
800 watts RMS
3" wide, long-wind AL voice coil
Dual 8.5" spiders with woven leads
Single 4 ohm DCR or Dual 4 ohm DCR
Actual weight: 29.5 pounds

[Dennis H]

No experience with PR design but Le is pretty close to Ls and Sd can be calculated from Dia.

[Hdale85]

Well using pr's is supposed to be pretty close to using a port (so kevin says???) he said the OEM10 PR is equal to a 4-5 inch port and said to use 2 for ultra low tuneing (told me 2 would be good for 20hz) he said the one they have for testing or what not is in a .33 cu ft enclosure with 1 PR.

Kevin calls them VMP's variable mass passvies...so I guess they are a little different? I don't know.

[ThomasW]

PR's and ports are both 'vented' alignments...

Having the T/S parameters (especially the weight) for the PR's is mandatory since the weight of the PR's and box size is what determines the Fb of the sub.

[Hdale85]

Ok well this is what Kevin said about them over there.

The VMP's are just that "variable mass passives" so the TSP's are also variable. Use whatever you what. They can expend from about 8Hz to 30Hz. Final box tuning can be between bout 15Hz and 60Hz, aprox.

[ThomasW]

I'm not disputing what he says,

BUT....

To tune the sub you need to know the weight of the moving mass of the PR, then the added mass is calculated.

If you have loudspeaker measurement tools this can be done by testing the Fb as more mass is added. If you don't have the loudspeaker measurement tools you need to know the weight of the moving mass of the PR, since it won't be the same as the Mms of the speaker.

[Hdale85]

Well I posted in the thread about it... see if he replies but every time someone asks about the pr's he doesn't seem to have to much to say?

[ThomasW]

Ask him for the Mms of the PR

[dyazdani]

This is what they show for the PRs on the website - this is for the 12 (they don't list the 10) BUT in all cases, the only difference is the diameter. The rest of the numbers are the same.

12" TC-VMP
Vap 0.0
Dia 250mm
Vas 0.0l
V-Fs 4Hz-24Hz
cms 0.0m/N
V-mms 500g-2500g

[WillyD]

But dyazdani, the cone on the 10" PR is the same as the one on the TC-10 OEM.

[ThomasW]

PR based subs are tuned to a particular Fb by having a specific amount of weight on the PRs.

In order to calculate the sub with a software sim, we need to know the stock or 'empty' weight (moving mass = Mms) of the 10" PR. Then we calculate the amount of addition weight that must be added to the PR's to hit the target Fb.

Without this info he's just going to be guessing at the amount of additional weigh that must be added to the PR's. (This is akin to airing up ones tires without a gauge.... :roll: )

We don't care about the weight of the speaker because it has a voice coil and the PR doesn't

[dyazdani]

Without this info he's just going to be guessing at the amount of additional weigh that must be added to the PR's. (This is akin to airing up ones tires without a gauge.... :roll: )

Yep - I read Dougie's post over at TC Sounds and that's basically what they are telling him to do. Basically to throw the PRs in there and get the tuning via trial and error. Not real efficient IMHO.

[dyazdani]

But dyazdani, the cone on the 10" PR is the same as the one on the TC-10 OEM.

That's what I'm saying, according to the specs, everything else is the same, just change the diameter. That said, they don't really give all the needed info anyway. I just posted all I could find hoping Thomas could find a golden nugget.

[ThomasW]

He'll need to follow the instructions in this thread to measure the Fb of the boxes.

https://www.htguide.com/forum/showthread.php?t=17794

[Hdale85]

They said the base weight is 500 grams. If it can efficiently be tuned lower then 20hz then that would be good....I don't know see what you can do with it.

[WillyD]

That's what I'm saying, according to the specs, everything else is the same, just change the diameter. That said, they don't really give all the needed info anyway. I just posted all I could find hoping Thomas could find a golden nugget.

But that isn't correct. The diameter isn't the only difference, the cone is also different. :T

And yes, they definitely don't provide enough info. Hopefully that changes...

[Hdale85]

I don't think they post the LE, SD or anything for any of their drivers....I guess you can figure it out if you know how but what about people that don't know how? Anyways thats what they said the MMS was is 500g hopefully thats enough now?

[---k---]

Are they being vague about the specs, since this is an OEM product and the OEM vendor won't allow release of the specs? I can imagine that if I were a big manufacturer, I wouldn't want people having access to my parts and specs and be able to make exact copies.

[ThomasW]

This is more than enough data regarding the woofers.

Qts 0.357
Qes 0.400
Qms 3.35
Fs 30Hz
Res 3.11 ohms
Ls 4.0 mH
Lp 6.26 mH
Rp 9.9 ohms
Dia 208mm
Vas 19.3 liters
Mms 224 grams
Cms 119 um/N
BL 18.35Tm
Spl 83.3dB

FYI,

Ls = VC inductance wired in series
Lp= VC inductance wired in parallel

[Hdale85]

So is 500grams for the PR not the right info either?

[dyazdani]

It sounds to me like 500g is the minimum weight that you can adjust. I would think the "empty" weight of the PR would be something much less. :huh:

[ThomasW]

The PR has some kind of mechanism that allows for attaching the weight. Frequently this is a nut/bolt (washers are the variable weights). So it's not unusual for the PR Mms to be higher than the driver.

[dyazdani]

The PR has some kind of mechanism that allows for attaching the weight. Frequently this is a nut/bolt (washers are the variable weights). So it's not unusual for the PR Mms to be higher than the driver.

Yeah, I thought about that after I posted but I wasn't sure if they included the weight of the post/bolt with the added weight or the empty weight.

[Hdale85]

Well I asked again and described what MMS was as well. Do none of them really understand speaker design or something? I would have thought that Kevin would immediately know what I needed and gave it to me?

[ThomasW]

The Mms of the PR is 500 grams

[Hdale85]

Thats what they said? Kevin didn't say it it was someone else but Kevin didn't disagree either.

[ThomasW]

This is taking forever..... :roll:

I should have taken a clue from the V-Mms range (500g-2500g) and assumed that 500g was the empty weight.

[Hdale85]

Thats what I'm figuring. It's the same for their other PR's so it would make since I suppose?

[Hdale85]

Well I'm thinking I'm going to dump the OEM10 with the 2 PR's and go with a single TC3000 15"...I emailed Heather about it to see if she could change the order since they have not shipped yet.

[Hdale85]

I'm not sure why I keep calling him Kevin.... Kevin = Kyle :B

[Hdale85]

Well I talked to Heather about changing the order and she said the 15" TC3000 is back ordered (I guess they don't update their page) And said to tell her what I wanted to do and then she would ship whatever well then I get home and she already sent the OEM10's....sooo if anyone can still help me out I guess the MMS for the PR is 500grams?

[Hdale85]

I PM'd Kyle about it to see if I could get some straight answers. If that doesn't work I suppose I will give them a call. I got the amp today though :B

[Hdale85]

OK!!!!!!!!!! I finally got some info out of Kyle this is what he said,

The moving mass is 370, the washer is 175, each washer is 80 grams. and the compliance is around 200 um/N

Will this be enough Thomas?

[ThomasW]

Yes, and this is what he should have posted days ago....... :roll:

[Hdale85]

Well the first pm I sent he said something like "I measured the MMS the other day but i forgot what it was, But the best way is to just mount the PR backwords add some weight and play a test tone and the tone that the woofer moved the furthest is your tuning freq" Well I told him thats too much guessing and that I want to know that I'm accurately tuning it so I guess he went back and remeasured.

[Hdale85]

Anyways if possible I'd like to see it tuned to about 15hz. My friend made up a model and it was doing 15hz at like 97db with 2500grams on each pr. Not sure if thats correct though? He said the xmax was at 14hz though. But anyways like to see what you come up with Thomas.

[WillyD]

I don't think I'd tune a single TC-10 to much lower than 20Hz.

[Hdale85]

Why not? It is a pretty amazing 10...I mean 28mm of xmax. Think 18hz or 17hz would be ok? Might help the xmax at 14hz quite a bit.

[augerpro]

Doesn't 5 pounds of weight swinging back and forth strike anyone as slightly ludicrous? I don't know much about subs or the physics involved but that just seems strange to me.

[Hdale85]

hmm...not really :B

[augerpro]

hmm...not really :B

Ok. Nevermind me ops:

[---k---]

Doesn't 5 pounds of weight swinging back and forth strike anyone as slightly ludicrous? I don't know much about subs or the physics involved but that just seems strange to me.

Dang metric system! I just assumed 2500 grams was small based upon what I expected.

Having never done a PR design, yeah 5 pounds sounds funky to me, but what do I know. I just wanted to post and complain about the metric system.

[ThomasW]

Unless the room is tiny, it's a but much to expect usable output from a 10" driver tuned to 15Hz, regardless of the available Xmax.

The catch-22 is a higher Fb is a good idea to increase the overall output. Then the risk of the driver unloading at lower frequencies becomes the issue.

18Hz might be a good compromise. But be very careful playing DVD's like LOTR or whatever, that have considerable infrasonic content.

[Hdale85]

Hmm well I'm still trying to get excel to work in linux but so far no good. My friend doesn't know how to actually tune a PR in unibox to a specific frequency. ~18-20hz would be good though. I wasn't really expecting this to go that low. And the room is quite small actually. About 14x13.

[Hdale85]

Thomas does 2500 grams sound like way too much? What is usually the most weight you put on a PR?