Woe, oh woe.
Employment is taking far longer to find in Montréal than I first envisaged, and to add to it - we've shifted our long-term plans towards Australia.
So, this leaves me in a pickle. My valve amp and Mission 701s are sitting on a pallet in my fiancée's mother's garage. 6000 miles away.
Growing more and more annoyed with the (lack of) sound from my laptop, I think it has come to crunch time. Build something that could quite easily be simply given away when we leave.
Cue the discovery of Solen Electronique, within moderate train-distance from Montréal. After searching on here, while no stellar performer, the Dayton DC160 seems to be a fairly good bet, and I have a set of Visaton dome tweeters I snagged a while back in Berlin here, so I'm going to harangue at it. I figure it'll be hard to go wrong for less than CA$100, in a properly designed ported/transmission line enclosure.
Those who have played about with the DC160, please share your thoughts?
L
Employment is taking far longer to find in Montréal than I first envisaged, and to add to it - we've shifted our long-term plans towards Australia.
So, this leaves me in a pickle. My valve amp and Mission 701s are sitting on a pallet in my fiancée's mother's garage. 6000 miles away.
Growing more and more annoyed with the (lack of) sound from my laptop, I think it has come to crunch time. Build something that could quite easily be simply given away when we leave.
Cue the discovery of Solen Electronique, within moderate train-distance from Montréal. After searching on here, while no stellar performer, the Dayton DC160 seems to be a fairly good bet, and I have a set of Visaton dome tweeters I snagged a while back in Berlin here, so I'm going to harangue at it. I figure it'll be hard to go wrong for less than CA$100, in a properly designed ported/transmission line enclosure.
Those who have played about with the DC160, please share your thoughts?
L
Classix (undefinition)
re: 'we've shifted our long-term plans towards Australia' - you'll need to bring your own water...
re: 'we've shifted our long-term plans towards Australia' - you'll need to bring your own water...
Which DC160?
There are three models, DC160-8, DC160S-8 and DC160S-4. Which one are you hoping to use? I'd be happy to model a TL for you but I need to know the specific driver and have an idea of cabinet size and shape you're after.
Paul
There are three models, DC160-8, DC160S-8 and DC160S-4. Which one are you hoping to use? I'd be happy to model a TL for you but I need to know the specific driver and have an idea of cabinet size and shape you're after.
Paul
Paul,
Which software are you modelling it with? I'm not scared of attacking something myself and am well versed in filter design - I'm increasingly looking at the Hi-Vi M5A, which, as a magnesium coned speaker, I'll have to notch filter at about 2.5-3k - but they actually go up there quite nicely. I have a pair of Visaton DTW72 tweeters that have been gathering dust for longer than is good...and they need crossing at 2500-ish...so all would lean well to crossing there with the M5As.
With a Qts of .34, the M5A's not actually a bad choice for a TL. I think I'll go for 1/3L tuning, which'll bring the response down into no-need-for-a-sub territory.
T/S follow:
http://www.madisound.com/catalog/PDF/m5a.pdf
Which software are you modelling it with? I'm not scared of attacking something myself and am well versed in filter design - I'm increasingly looking at the Hi-Vi M5A, which, as a magnesium coned speaker, I'll have to notch filter at about 2.5-3k - but they actually go up there quite nicely. I have a pair of Visaton DTW72 tweeters that have been gathering dust for longer than is good...and they need crossing at 2500-ish...so all would lean well to crossing there with the M5As.
With a Qts of .34, the M5A's not actually a bad choice for a TL. I think I'll go for 1/3L tuning, which'll bring the response down into no-need-for-a-sub territory.
T/S follow:
http://www.madisound.com/catalog/PDF/m5a.pdf
I do all my TL modeling with Martin King's MathCad-based software (worksheets).
So, you're changing from one of the DC160 models to the M5A?
So, you're changing from one of the DC160 models to the M5A?
Well, Martin King has a link to the free version of MathCad on his site and you can "subscribe" to his Worksheets for $25 unless that's not possible with your lack of employment. If you tell me exactly what driver you want to use and give me some cabinet druthers, I'll gladly model a TL for you.
Paul
Paul
Well, a baffle width of 25 cm (~10") is quite a bit wider than what is needed for the M5A. Also, I don't understand what you mean by "about 100 cm for 1/3L". Please elaborate (no, it's not your use of metric units that's confusing me, BTW).
Paul
Paul
I was thinking around 18 cm would be good for the baffle width. Sorry to come across as dense but were you suggesting a line length (probably the internal height of this cabinet as an ML-TL) be 100 cm? If so, that's also about right for this driver.
Paul
Paul
The modeling result...
Okay, I modeled an ML-TL using a cabinet having internal dimensions of 5.5"W x 5"D x 38"H. The center of the M5A is located internally 7.5" below the top, and the mass-loading port's center is located internally 2" above the bottom. The port has a diameter of 2" and a length of 3.5" and can be located on either the baffle or rear panel. I used a stuffing density of 1 lb/cu.ft., requiring a total amount of stuffing of ~5 ounces to be distributed uniformly in the top 19.5" of the cabinet's height. I've attached the system response graph (the red line) which predicts the output with a 2.83-volt input. The system tuning frequency ended up at ~45 Hz.
Paul
Okay, I modeled an ML-TL using a cabinet having internal dimensions of 5.5"W x 5"D x 38"H. The center of the M5A is located internally 7.5" below the top, and the mass-loading port's center is located internally 2" above the bottom. The port has a diameter of 2" and a length of 3.5" and can be located on either the baffle or rear panel. I used a stuffing density of 1 lb/cu.ft., requiring a total amount of stuffing of ~5 ounces to be distributed uniformly in the top 19.5" of the cabinet's height. I've attached the system response graph (the red line) which predicts the output with a 2.83-volt input. The system tuning frequency ended up at ~45 Hz.
Paul
Attachments
I think that the line would be about twice this length? Using one of the online calculators, it comes out at 1/3L tuning, the line is 1.86-ish meters, and the cabinet is 100cm high?
Upon reading - what I was looking at is an open-ended transmission line. I'ma going to buy those papers and start fiddling!
Upon reading - what I was looking at is an open-ended transmission line. I'ma going to buy those papers and start fiddling!
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It depends on the results you want and how good those results may or may not be as far as the line length is concerned. AFAIC, based on modeling many, many TLs of various types, this driver's Fs and Qts indicate an optimum tuning frequency of 40-50 Hz. Now, if you want a traditional TL, not tapered or mass-loaded, a length of ~75" would give the same system tuning frequency, but the response would really be lumping and ugly unless you stuffed the life out of the line, meaning no bass contribution from the terminus and, IMO, not worth the effort in the first place. You may feel/think differently.
Paul
Paul
After pootling around a little with the 'open ended' (read - non tapered or non-mass loaded) and changing the driver to an M6A which seems to fit the bill a little better, both Qts and Fs-wise, the plot seems pretty good. One thing that does confuse me a little thus far is the lack of folding within the box - it just mentions the length being 72". I presume I can then fold this into a 36" box, once one folds the TL with a central baffle? Nothing such shows on the design - just what looks like a large ported box!
Provide me with the details on what you modeled; internal width and depth of the line, location of the M6A's center from the closed end of the line, stuffing density and length of line stuffed from closed end, then I can model the same as see what the response looks like. Yes, you can fold the line but if you model a 72" line length and fold it into a box with an internal height of 36", the line's actual length will be slightly larger, 72" plus the thickness of the central baffle making the fold.
Paul
Paul
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