Build or buy, speaker options


I have a pair of Triangle Volante 260 speakers which I love dearly most of the time. The times that don’t love them dearly are the Fridays when I get home from work and want to shed the stress of the week with a little high energy wall of sound type tunes. As mentioned before in this forum, the midrange and high end quickly fade out after a short while at high volume, then fade back in when I turn the volume down. Georgehifi posited that it could be iron core inductors in the crossovers getting saturated, and that sounded feasible. But, in an email conversation with Madisound, their tech indicated that he’d never experienced such a behavior, and that saturated inductors were more likely to exhibit distortion. The tech ask for some photos of the crossover, but I wasn’t able to get a clear shot of one of them, and trying to remove one from the cabinet proved much more involved than I thought it would. No good photos, but I did see iron core inductors, for sure. The Madisound tech thought “Maybe they are using poly switches that close when the power is too high, putting the speakers through a resistor”.  This is something I’ve never heard of, so I’m totally unfamiliar with poly switches or what they might look like.  It’s looking like I may not be able to solve this problem. 

The options I’m considering are selling the Triangles, and purchasing used market speakers, or building my dream speakers.  

If purchasing used, the qualities I like in a speaker are: detail, frequency balanced but leaning slightly toward warmth, tight punchy bass with authority, and higher frequencies that are truthful and never screeching. They would also need to handle a fair amount of SPL without strain. Amplifiers are Parasound JC 1’s.

If making my own, I’d be shooting for the same qualities. With that in mind, I’m considering a sealed cabinet design for two 8” woofers.  Separate cabinets for midrange and tweeters, also sealed. I think I’ve decided on the drivers for the bass cabinets, the Morel CAW938 9" Woofer, which is an excellent driver for sealed design. The midrange, I’m considering either one or two drivers per cabinet, the reason for two would be power handling, although I’m also thinking that this may be overkill, and that one driver per, with good power handling may be the ticket. Manufacturers I’m considering for midrange are Morel, Seas, and ScanSpeak. Tweeters are yet another big question, but the more I research the topic, the more I lean toward soft domes, same manufacturers as the midrange. 

Crossovers are yet another War and Peace length set of considerations,  but I am thinking about active crossover between the bass cabinets and the mid/tweeter cabinets, a passive crossover between the mids/tweeters. Amps for the bass cabinets would be newly acquired D class, possibly in the 500 wpc range. I’d use the JC’s for the mid/tweeters cabinets. 

I’d be interested in any advice, comments, experiences of others, as long as they aren’t overtly rude.  Budget for either purchased or built would be in the $4000-$6000 range.  

And, I’ve been following with interest a thread on this forum regarding the merits/drawbacks of sealed and ported systems. Some interesting observations and opinions. 


dprincipato

Showing 2 responses by timlub

I'm not familiar with the Triangles, so I am only commenting on what could be happening. Unless you listen at volume levels that can cause amp clipping, you should not be saturating cores... First, do you know that the cores are iron for sure or another material?  The Madisound rep was incorrect. When a core saturates,  the inductance changes,  thus the frequency of the driver that it is in series with will also change, the top end can fade away.  This will most likely be a mid or woofer, a tweeter would not use a inductor in series.   Overall,  most good cored inductors are rated to handle 300 plus watts before saturating.  Even though possible, it is not likely that is the issue.  As far as some sort of switch.... I have use a type of thermistor as well as low voltage bulbs that will bleed off excessive current during amplifier clipping.  I've not seen anyone else do this.  It isn't rocket science,  I've just not seen it used out there,  they do hurt the sound quality of the driver that they are on.   I had to stop a kid from blowing stuff up.  As far as your own build.  I would recommend some pro parts or at least something with some high sensitivity so that you won't necessarily drive your amp so hard.  Good luck.  I hope this helps in some way.  Tim 
@ dprincipato 
Sorry,  I just came back to this thread after a couple of days.  Most good designers use air when at all possible.  Occasionally,  a core is a must because of DCR.  A Steel laminated core will not saturate as fast as iron ferrite.  The problem is if you measure DCR on an air core of any value, you might have 2 to 4 ohms,  when you measure DCR on a good Steel Laminate core,  it is more like .2 ohms.... when you replace the coil and add the extra resistance, it is very likely that you would reek a bit of havoc with your crossover.   I have a few of the best steel laminated core coils that I have ever seen,  they measure about 2.1mh and are a .13 DCR,  they are a 14gauge magnet wire..... If you can get a measurement of your current coil,  I could send you a couple of these to replace.  If you are not experienced in crossover work,  I recommend leaving it alone.  What part of the country are you in?