I agree. Looked at a few 8HD online and mine seems different. Pic attached. Mouth is 7" x 17". I am still kinda in shock how heavy this stuff is. Horn and driver are close to 10lbs each. In addition, the crossover components are equally massive to me. There is a capacitor in there that's larger than a D cell battery and an inductor which looks like a flux capacitor to me. 
Tinkering around with simming the cab in HR if anyone is interested (started another thread).
Tinkering around with simming the cab in HR if anyone is interested (started another thread).
Attachments
Ok. Starting to get a game plan for getting these out of the garage and into the house and functioning. Goal at this point is 2 way. JBL 2220 driver in the mid bass cab and a Selenium D202ti in the horn pictured above. Plan to roll my own XO from Parts Express, passive at 1.5k. A big ole DIY HT sub will come later... There was some difficulty simming the cab in HR due the vent in the horn, but the horns output seems to be agreed upon. Here is on axis response horn only. A little unsure what happens when horn loading a HF 106db driver? Or does the spec assume horn loading? Might be time to post in multi way but that place scares me
Am I setting myself up for failure? I do not consider this to be any ultimate system but a bare bone efficient setup and something to tinker with when time and funds allow. Later, I will find a larger horn and driver for HF and maybe lowering XO point or maybe even active.
Am I setting myself up for failure? I do not consider this to be any ultimate system but a bare bone efficient setup and something to tinker with when time and funds allow. Later, I will find a larger horn and driver for HF and maybe lowering XO point or maybe even active.
Attachments
Sam,
106 dB would be fairly typical broadband sensitivity for a (cheap) HF driver on a 90 degree horn.
The EV 1824 would probably be a better mid driver than the D202ti, and the T35s (not T350, which was a "baby butt" type horn) you have would have more extended and wide dispersion HF, the old cast mid horn is probably quite beamy above 6 kHz.
I had not looked at the cast mid horn in the OP, it looks like the one Kustom used in their cabinets in the 1970s, only with the interior vertical ribs removed.
Have you listened to or measured the response with the original drivers?
Art
Attachments
Last edited:
Thanks Art. I think your spot on about the horn although mine do not appear to be modded and maybe the ribs were left off deliberately for mid drivers. Nope, haven't fired them up yet. These were part of the "package deal" as in you want the bass cabs you have to take these too... I suppose I should just use them 3 way but I have become enamored with the 2 way VOTT thing. This gets them out the garage and the wife can have her space back!
While I have your attention, what do you think would the best bang for buck HF setup for these mid bass cabs? I think some of the VOTT excitement has caused some undue inflation in prices...
I suppose I should just use them 3 way but I have become enamored with the 2 way VOTT thing. This gets them out the garage and the wife can have her space back!While I have your attention, what do you think would the best bang for buck HF setup for these mid bass cabs? I think some of the VOTT excitement has caused some undue inflation in prices...
Sam,
The best "bang for buck HF setup" is the one you already have ;^).
Having heard both the smaller horn VOTT set up (511?) with aluminum diaphragm tweeters running from 800 Hz (or maybe 500 Hz) up, my preference (assuming properly crossed over) would be what you have. The 1824 can go low without "coughing".
That said, the T-35s require real attention to detail when putting in the diaphragms (as do the Altec drivers), so if they don't test out evenly, there may be some work required. Having the HF drivers centered over the mids would also be preferred, though mirror imaging them "as built" is not that bad either.
Art
Thanks again Art. Warming up to a 3 way system and plan to ditch the HF cabs and go naked thus keeping a VOTT "look" and will align tweeter with mids. There are definitely some EV T35 fans out there and my research confirms what you say about EV's QC/diaphragms. Challenge now is finding a driver for the bass cabs. I am striking out on my JBL 2220 leads. Anything cost effective popping up in your head that might work? A few Eminence drivers simmed half decent but the consensus is that this cab cannot be modelled well.
Classic VOTT had the HF sitting above the 15" box, which gets the HF at head level, where you want it. Those aluminum horns tend to ring badly if not mounted in a box.
The box is just a Perkins type bass reflex with a stubby mid horn that will jack up the 160-900 Hz response by about 3 dB. Kappa 15 would probably work OK, or whatever Eminence you have found "half decent".
Thanks again. Guess I'll just keep them in the fugly cabinet. I planned to use it until I realized I can't relocate tweeters to center with mid. Not sure if this is typical or not, but after simming a dozen or so drivers I see a pattern emerge with the boutique or classic drivers have extended mid and HF response. Is this typical? Just simmed the EV 15L and it looks as good or better as the 2220.
Drivers like the 2220 and the 15L (Lead, as in lead guitar) were designed to go high and be efficient, all pretty typical in the transition era when 100 watts was still considered a lot of power.
The EV 15B (Bass) had less cone breakup, it would be a good choice for your bins if you can find a pair cheap, but you probably are better off with new Eminence for similar $$.
Last edited:
Any care to offer an opinion? Pic attached is EVM 15B vs Dayton PA380. Bold is EV and grey is PA. Sim is definitely suspect as it cannot be modeled correctly in HR but I am curious if it would worth another C note for the EV15Bs. Maybe I am OCDing but still learning... THANKS
Attachments
Frazier stuff
Frazier white paper on coaxial
http://www.frazierspeakers.com/download/coax.pdf
12" woofer/horn coax
http://www.frazierspeakers.com/download/c66.pdf
Cat 40
http://www.frazierspeakers.com/download/c40.pdf
Cat 499 (a bit more power handling, round horn)
http://www.frazierspeakers.com/download/cat499.pdf
Frazier white paper on coaxial
http://www.frazierspeakers.com/download/coax.pdf
12" woofer/horn coax
http://www.frazierspeakers.com/download/c66.pdf
Cat 40
http://www.frazierspeakers.com/download/c40.pdf
Cat 499 (a bit more power handling, round horn)
http://www.frazierspeakers.com/download/cat499.pdf
If you are not planning to use subs below these, you should lower the tuning by about an octave to around 35 Hz. After doing that you can get a more realistic idea of which will work better, but according to the sim the PA380 is not going to have the midrange sensitivity of the 15B, assuming you have entered parameters correctly.
That said, the difference of 10 dB at 400 Hz seems far greater than I'd expect, re-check all your TS entries.
Yep; planning on a sub. I've rechecked the TS data more than several times and have confirmed with another member the offending piece of data is a very high Le for the PA380. Le for the PA380 is 4.12. Very odd to me. Typically I see it near 1.0 and if I change Le to 1 it sims much better, but still not as good as the EVM15b. What's crazy is there is a MCM Electronics driver that sims nearly identical to the 2220 but unsure of accuracy of the TS data. MCM Audio Select 15'' Die Cast Woofer with Paper Cone and Cloth Surround - 200W RMS 8ohm | 55-2963 (552963) | MCM Audio Select Would be tempted to give it a shot if you think it is a passable driver. That said, an all EV system would be very cool thing to me.
my 15B's are old - not sure how the aftermarket cone kits measure - that might be an ok MCM - would guess Qt to be double or more what they claim - 2220 had low mass, low Qt, thin curvilinear cone - will a 15L cone kit fit the 70's SP15A? (mine were ~like a "6 ohm" 15L but with whizzer cone and 2 ohm series resistor hidden under a spoke to raise Qt)
Sure; if you look at this post http://www.diyaudio.com/forums/subwoofers/276150-hr-questions-vented-bass-horn.html you will see this cabinet cannot be accurately modeled but I digress. Something is better than nothing I suppose.
I am slowly coming to terms with trying to find budget drivers for this cab... Someone could correct me if I am wrong, but the "magic" of sticking these horns in your home is to enjoy the great sensitivity over average gear, right? So, if I stick a less sensitive driver in this cab I am defeating the main principle of using such a horn. In addition, I am just asking for problems if using PA mid and HF horns.
I am slowly coming to terms with trying to find budget drivers for this cab... Someone could correct me if I am wrong, but the "magic" of sticking these horns in your home is to enjoy the great sensitivity over average gear, right? So, if I stick a less sensitive driver in this cab I am defeating the main principle of using such a horn. In addition, I am just asking for problems if using PA mid and HF horns.