TH-18 Flat to 35hz! (Xoc1's design)

Instead of using a stand you can put the mic on a piece of foam on the ground. That way the mic isn't making sound (at least less) contact to the ground. You can also push the cab a meter or more (incl measuring mic) in any direction to see if it makes a difference in relation to the room acoustics.

But your measurements from post #377 seem to be in line with predictions and finds from GS3525. Your -3dB point is at 41Hz, if I’m correct, which is slightly better as predicted but that is probably the (positive) influence of the room acoustics.

Looks good :up:
 
I did manual spl measurements with REW using the generator to generate a series of frequencies and wrote down the spl meter reading
results are much more realistic and inline with previous measurements of others.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.
"C" weighting rolls off a bit of the low frequency.
 

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"C" weighting rolls off a bit of the low frequency.

I have done some more analysis on Ljk11,s excelent measurement data.:)
I used this web based calculator to compensate for the C weighting at the measurement frequencies.
dBA - Calculating weighting filter frequency to dBA and dBC DIN IEC 651 calculator equal-loudness contours - sengpielaudio Sengpiel Berlin
and added the values to the spreadsheet.
I then added the values for the response as simmed in Hornresp@ 2.83V
Finally I added an offset to the response curve to normalise the response to the hornresp values at 50Hz
The Measured values are surprisingly close to the Hornresp Sim!

Unfortunately the RCF L18P300 is not really ideal in the TH18.
Not accounting for any compression losses,
X max 7.8mm is reached at approx 250W (44.72V)
PD1850 11.25 mm X max is reached at approx 800W (80V)
The difference when both are driven to Xmax is charted in the Hornresp screengrab, RCF is Black PD1850 is grey......;)
Regards Martin (Xoc1)
 

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I am looking to build 4 of these I have heard the TH18 of Danley at Orlando InfoComm past June is sound great tones are detailed. I cant explain it it just different from what I am used too with folded horn cabinets CV L36 I've used for a long time for mobile. these TH sounds smoother although requires more amp power and Xmax. Would the new Fane 18XS be good for this cab X 4??? Thanks!
 
I am looking to build 4 of these I have heard the TH18 of Danley at Orlando InfoComm past June is sound great tones are detailed. I cant explain it it just different from what I am used too with folded horn cabinets CV L36 I've used for a long time for mobile. these TH sounds smoother although requires more amp power and Xmax. Would the new Fane 18XS be good for this cab X 4??? Thanks!
The DSL TH-118 sounds smoother because it is smoother and goes lower than the CV L36. It is also louder with less power, though can take far more power with far less thermal compression.
If you like the way DSL-118 sounds, use the speaker DSL uses, the BCSW115-4.
 
Hi!
The work continues and I have made one

http://img2.uploadhouse.com/fileuploads/15342/153429823ecaf2e3a1ceddb1c30c53c941e5ee24.jpg

Put two more slots 4x19mm at the botton at each side of the central brace, as I’ve already fixed the vibration I notice at that points in the SS15 and appeared it quieted.

Braces are a lot

http://img3.uploadhouse.com/fileuploads/15343/153431337d36989326a4cd1909411570ced5495a.jpg

Today I was taking measurements of TH18, also loaded with the 18Sound 18NLW9600, at same place we tested the Keystone, same equipment,…
And than Pequeno has picked up what’s wrong with peak meter hold.
The decibelimeter 9V battery, bought at some weeks ago, Rayovac alkaline has only 7.5V at the multimeter DC meter.
Measured the TH18 Xoc1 and it stops at 117dBs using similar power as input for this driver in the Keystone (past 2300Wrms 8ohms loaded, without clipping the Machine AB+H 9400 amp).
Changed the drained battery for one with full 9V and goes to 126.2 peak holder from 38 ~ 97Hz band, also with very good hi-fi sound, and a bit better defined says my friend who also plays bass guitar.
The cone control IMO, wasn’t as good as in the Keystone, which sound I preferred, maybe because I’ve owned a DJ PA in past, where lows are more present than at live music that my friend is more used to.

http://img1.uploadhouse.com/fileuploads/15343/1534303134b74bd2481a44dd4c596a4852bd39e8.jpg

As it shows a # of less 9.9dBs before changing the battery, adding this to 118.9 red when measured Keystone TH the correct number will be around 128.8dBs, which is a lot thru the band played and with excellent cone control for a TH, only owned by the TH12 loaded with B&C 12PS100 up to date tests.

At my friends place they have other two drivers I would test e so we go on with:
First 18 Sound 18LW2400 – plays with a bit past half that power, sounded a bit better (not so low as 9600 with a bit more upper sound in the band (38 ~97Hz LR24), but it couldn’t have more power because cone control is uncontrolled when you raise the potenciometer; insist is a way to a fail; peaks at 125dBs.
The last one tested was the B&C 18TBX100 – plays more like the 18NLW9600 sound, accepts more power, with better cone control than the 18LW2400, and peaks also at 125dBs.

IMO the 18NLW9600 plays better, has more cone control despite the power injected, the motor was only tepid after more than half an hour at war Pe, plays cleaner, and will be better for DJ use when you need more lows.

Cone control is the only problem I see with THs. The sound is like hi-fi, if you have the right driver and have limits to drive it .
Pass the limits and the way to fail is near.

What to comment on numbers showed at the marketing papers, using similar designs and drivers , with numbers like 137dBs output (10.8dBs more than the here pictured one, and 8.2dBs more than the keystone) , 143 PEAK (16.8 dBs more peak - joke?).
Regards,
 
So basically these drivers are taking full AES power with no problems as hornresp predicts (with proper high pass filters)

About the high pass filters. They were calculated a few pages back...but you're saying you used a high pass at 38Hz LR 24db/octave right?

Did you try a different HP for extended bottom? Or we're you only concerned with 38hz and up? (about what the tuning of the TH is...)
 
So basically these drivers are taking full AES

Did you try a different HP for extended bottom? Or we're you only concerned with 38hz and up? (about what the tuning of the TH is...)

Hi!

Yes.
The only one that I think could admit a bit more is the 18NLW9600 but with an amp that could deliver more W at 8 ohms loading; maybe 4 ohms drivers is a better option. The one we used can deliver 2300WRMS continuos and clean, not that 33ms things now in use (33/1000 second sustainable).
When you play an note and let the cord of the bass guitar ressonating you can make an agree with the amp to sustain it?
Are we forgheting the past parameters like WRMS continuos changing it for all these chinese things invading our markets, digital desks, joke amps, ... exporting our jobs to them... time will show us the truth or not.

Tried various from 30Hz ~ 120Hz. We agreed that best sound comes out when band was 38 ~ 97Hz LR24.
Over 97Hz the upper notes tend to be not defined.

Bellow 38Hz cone control is absent with 18LW2400 at Pe limit. It tends to whip ("chicotear" in portuguese) and is an invite to fail.
Forgot to try the TBX bellow 38Hz but the way the cone control goes from 38Hz makes me fear with it's survival.

This confirms my findings with the SS15, where in contact with Jbell, I'm put circular restrictions at the throat in order to increase cone control and so less power compression at the limit (around 2.63:1).

http://img1.uploadhouse.com/fileuploads/15296/1529618099c2bb73abec30e6b8a3d7caa3d91033.jpg

These drivers cost a lot here and so must be conservative.

Regards,