Maverick59 Posted November 12, 2020 Posted November 12, 2020 Hi Guys I have a Centre speaker and am wondering if it’s going to be better ported . I have downloaded the Winlsd pro program and modeled up three comparisons. The yellow line is my speaker at the moment and is a sealed cabinet. The Red and blue are the same cabinet but with 2 different port lengths. What I am not sure about is the curve and what is the best out of the 3 . Any help would be much appreciated cheers Adrian
Maverick59 Posted November 12, 2020 Author Posted November 12, 2020 Oops sorry guys l attached the wrong photo
almikel Posted December 20, 2020 Posted December 20, 2020 IMHO DIY ported speakers are much harder to get right compared to sealed. In addition to that, the centre channel is all about vocals and dialogue, not bass. Do you have EQ capability for the centre channel? If so you could easily replicate the bass response of the ported designs with the sealed design as long as you're not running out of excursion (ie getting close to the Xmax on the driver) and have enough amp power to manage the EQ without clipping the amp. IME, modelling tools such as WinISD will be pretty close for sealed designs. A ported design may take some tuning/prototyping of the box volume/port length/port diameter/box stuffing to replicate what the tool (WinISD or any other) says. Being a lazy DIYer, I'd recommend sealed always - you'll get it right 1st time. Mike
almikel Posted December 20, 2020 Posted December 20, 2020 I just re-read your post - you already have a sealed centre channel and are asking if you should build a ported box with the same drivers? By far the most important thing for a centre speaker is that it matches the tonality of the main (left and right) speakers. 3 identical speakers for left right and centre is a common approach - maintaining the same orientation for each speaker is important - simply flipping the centre channel 90 degrees to be horizontal is not a great approach. Lots of manufacturers will build dedicated centre channels that are horizontal, but in 3 way designs they'll maintain the vertical tweeter/mid orientation and place a woofer either side. If building new centre channel speaker, focus on getting it to sound the same as your mains - if your mains are ported then maybe build your centre as ported - but more important would be to match the drivers and crossover. Mike
Maverick59 Posted January 2, 2021 Author Posted January 2, 2021 Hi Mike I made l left and Right speakers and when in use l sit them horizontally on top of the TV cabinet . When not in use l keep them in the two end sections of the TV cabinet keeping the war office happy lol. The drivers are all the same for the L&R and the center speakers. TSCW 636 Morel drivers and Fountek Neo CD2.0 ribbons are used for all the speakers. The centre speaker is basically two speakers built as one and has two identical crossover’s the L&R speakers also have the same crossover’s. l built these speakers to the size recommended to me at the time. I started playing with Winlsd and it was telling me that I had enough box volume to make the cabinet ported . I made another two L & R speakers over the break and have ported them just to have a comparison will hopefully get them finished this week and test them out against the sealed version . lf they sound OK l will port the centre channel so all three are the same . I use my system for 99% movies. I been looking for some 75mm rubber plugs that l could use to plug the ports should I ever want to listen to a musical . l have been told that Greatest Showman has some excellent tracks the will give any system a good workout. Thanks Mike for your comments and Happy New Year to Everyone. Adrian 1 1
Al.M Posted January 2, 2021 Posted January 2, 2021 Perhaps yellow curve is better, but without knowing more and being unclear it’s hard to tell. Since you have built it now how does it sound anyway?
Maverick59 Posted January 2, 2021 Author Posted January 2, 2021 Must admit it does sound amazing but every one still looks to improve. so looking forward to seeing what the difference is weather is be good or bad . The ported version will have more bass for sure but will they be better maybe not, but l can fit the plugs and keep them sealed . Like they curiosity killed the cat lol
almikel Posted January 13, 2021 Posted January 13, 2021 On 02/01/2021 at 1:10 PM, Maverick59 said: Hi Mike I made l left and Right speakers and when in use l sit them horizontally on top of the TV cabinet . When not in use l keep them in the two end sections of the TV cabinet keeping the war office happy lol. The drivers are all the same for the L&R and the center speakers. TSCW 636 Morel drivers and Fountek Neo CD2.0 ribbons are used for all the speakers. The centre speaker is basically two speakers built as one and has two identical crossover’s the L&R speakers also have the same crossover’s. l built these speakers to the size recommended to me at the time. I started playing with Winlsd and it was telling me that I had enough box volume to make the cabinet ported . I made another two L & R speakers over the break and have ported them just to have a comparison will hopefully get them finished this week and test them out against the sealed version . lf they sound OK l will port the centre channel so all three are the same . I use my system for 99% movies. I been looking for some 75mm rubber plugs that l could use to plug the ports should I ever want to listen to a musical . l have been told that Greatest Showman has some excellent tracks the will give any system a good workout. Thanks Mike for your comments and Happy New Year to Everyone. Adrian Hi Adrian, beautiful speaker builds - way superior DIY than I've ever done! But the photos show some "interesting" speaker design decisions you've made regarding tweeter orientation. What is the tweeter orientation in your left and right main speakers compared to the centre channel? It appears you've gone with vertical mounting of two tweeters for the centre channel and horizontal mounting of the tweeter for the left and right main speakers? I've never used ribbon tweeters, but purely based on their dimensions their polar pattern is very different between vertical mounting and horizontal mounting. I've only ever seen ribbon tweeters mounted vertically - what does the tweeter manufacturer recommend? Your speaker design appears to be along the lines of a D'Appolito design, ie symmetrical mid/tweeter/mid - and the symmetrical design may work fine with the tweeters mounted that way...but I think it would sound better if all your tweeters were in the same orientation, and I expect the recommended orientation would be vertical... ...I also think a single tweeter in the middle of the centre channel would likely work better than the 2 tweeters you have...at tweeter frequencies that centre channel will have lateral peaks/troughs due to comb filtering from the 2 tweeters, ie laterally across the listening couch, the centre channel frequency response will be very lumpy at the tweeter frequencies if you move left or right - a single tweeter in the centre channel wouldn't do this. Your cabinetry work is exemplary - way better than mine - but some tweaks on your speaker design would be worth considering: check the manufactures' recommended orientation of their tweeters - as I said above, I've never seen ribbon tweeters mounted horizontally - but they may work fine in your D'Appolito/MTM main speakers with ribbon tweeters, their polar response will change significantly depending on mounting vertically or horizontally You want to match the speakers' responses between main speakers (left and right) and centre channel as closely as possible - having a ribbon tweeter offset by 90 degrees between centre and main speakers is not a compromise I would make - the tweeter orientation across mains and centre should be the same Back to your original question about ported vs sealed? I would recommend staying with sealed for DIY - very easy to design once and get right with one lot of sawdust - getting ported designs right is much harder...going sealed may require EQ...but IMHO EQ is better than ports for numerous reasons. Your Morel woofers are 6" or so - very nice drivers - but if you want low bass at reasonable SPL you're going to need 1 or more subs down the track ...sealed mains are easier to integrate to sub/s than ported mains. cheers Mike 1
Maverick59 Posted January 13, 2021 Author Posted January 13, 2021 Hi Mike The L & R mains sit on top of the TV cabinet horizontal so the ribbons a all sitting vertically . The centre speaker is actually two speakers in the one cabinet and there is two crossover’s wired to one set of speaker posts . I could not find anyone that would make me crossover’s at the time , but l have since found someone l wouldn’t mind making another centre with one ribbon to compare them. I do have a wee sub Dayton UM 18-22-18 in a 6 cubic meter cabinet and using the Dayton 1200 DSP amp . Thanks for your comments and help it’s much appreciated. Cheers Adrian 2
almikel Posted January 20, 2021 Posted January 20, 2021 On 13/01/2021 at 11:29 PM, Maverick59 said: I do have a wee sub Dayton UM 18-22-18 "wee sub"...pure gold!
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