Suitable speakers for the KT88 SET project

[aemcgo0]

Hello all,
I posted this over at the DIY Audio Projects forum and have gotten no response so I figured I would post it here. Opinion on next project But I got it my new KT88 SET amp working Tuesday night for the first time, and it sounded great even with the cheap 91dB speakers I had hooked to it I have attached the schematic for reference. It is based on the Abdellah KT88 SE project over there.

So all this leads me into my next project. I would like to build some high efficiency speakers to pair with this thing. Now I will say I have quite a bit of wood working experience, but none that is speaker related, all furniture and the like.

So my question is this , and I know this is a matter of taste and listening preference , but what are some speaker systems you guys are using to listen to a SET amp like this? I don't think that I want to go too terribly expensive just yet, but would like to look at something that really sings out with this amp. I'm thinking $350-700 USD for drivers. I'm not intimidated by the construction, I work at a machine shop and if it gets too difficult to build I can take them into work and get one of the CNC guys to cut out a flat pack for me. I'm intrigued by the concept of transmission lines, but that doesn't seem like a great candidate for this application. Am I wrong? What books would you recommend to get started in speaker building? I'll say after building this amp with point to point wiring and all, I'm thinking speaker building might be kind of a fun break.

Well there is one other requirement, I'm getting married in September and the significant other will have to "approve" of the looks. This COULD be the true challenging part.

Thanks ahead of time,
Adam

[planet10]

If you are looking at a multiway you need to put something together that has a very flat impedance curve. The XO itself is more of a challenge to an SE than the efficiency. (ie in a lot of cases a single FR driver of lower efficiency will do much better than a multiway with a complex XO)

There is something magic about SET & a good FR. We recently had a tasting session which might be relevant. Alpair selection...

As far as WAF goes, one of the speakers in the above has been met with appreciation from a number of Ws.



dave

[Helmuth]

Hi I am often designing high efficiency speakers to see what I could build. What I see that the subbas requirement will dictate the average spl level.

As hold on cutt-off at: 30Hz 93-94dB, 40Hz 95-96dB, 50Hz 96dB ,60hz 97dB.

Beyma SM115 15inch high quality medium priced. Hard to find a better one.
180 litre -3db 40Hz, spl 97,5dB 1Wmtr

Mid like this B&C B&C 6MD38 6-1/2" Midrange Speaker

High a nice 1 inch driver and horn B&C DE25
Or for Hifi a nice ribbon. Like this fountec:https://www.madisound.com/store/prod...oducts_id=1556

A for design it would be nice to have a woofer enclosure with on top of that a two way box with the B&C mid and the fountec ribbon. You will have 98dB 1 Wmtr !

Maximum sound-pressure at 10W 108dB 1Wmtr. and very low distortion. The set will cost around 1000 dollar.

[Helmuth]

A other combination.

Woofer beyma 12BR100.

mid audax: https://www.madisound.com/store/prod...oducts_id=8928

Tweeter morel https://www.madisound.com/store/prod...oducts_id=8342

You will end up with topclass hifi/studio drivers and 93dB 1Wmtr -3db 35Hz highly detailed. At 10W max/spl 103dB 1mtr. First order filter. With dayton caps.

[Helmuth]

Originally Posted by aemcgo0

Hello all,

Well there is one other requirement, I'm getting married in September and the significant other will have to "approve" of the looks. This COULD be the true challenging part.

Thanks ahead of time,
Adam

Hey does she really love you than she can't complain you have a hobby.

[aemcgo0]

Hey thanks for the quick response Helmuth and Planet 10,

I have to admit that all three suggestions sound like excellent plans. Of the suggestions so far, due to cost and complexity, I'm leaning towards the Planet10's MarkAudio. Maybe the Alpair 12's in the pensil enclosure? I know there is an excellent walkthrough on here already regarding setting the thing up. My only objection would be that I would like to try my hand at crossover design. What books and would you suggest to read on the topic? Maybe build it similar to the http://www.freifisch.com/pdf/alpair12.pdf? I think this combination sounds quite intriguing. Just need to brush up on my german. Been a few years since I was there...

For this driver would this amp/speaker combination be good candidate for a bass reflex type enclosure with a stand alone HF driver? I see those have been done as well.

Again thanks for the help.
Adam

[aemcgo0]

OK, so after thinking about it more last night, I think this is the direction I'm going to go. This is the mark audio 12's in the pensil box, with a ribbon tweeter mounted in the top box. But I have one question, is there a recommended volume for high frequency drivers? I can understand there being a volume requirement for the larger drivers as they drive larger amounts of air, but does the same hold true for the high frequency stuff?

I went and modeled the enclosure in my CAD software so I could begin getting a cut list together.

Thanks for the help,
Adam

[motosapien]

Someone had an Audio Nirvana Super 12" based speaker at the recent Lonestar Audio Fest that got good reviews. Those large full rangers can have an impressive sound along with very high effiicency. Lone Star Audio Fest 2011 -- Dallas, TX - see post 39. Seas has an 8" full ranger with high spl too - https://www.madisound.com/store/prod...oducts_id=9036.

[rvrazvan]

Go with a full range driver and add a subwoofer to the system(with a separate amp).

[aemcgo0]

So here we are, I decided to ultimately go with the super pensil boxes with a mark audio alpair 12, with no tweeter or subs just yet. I want to built my own pair of subs for them eventually. I get the cabinets constructed today do to an extra day off on the holiday weekend. I haven't ordered the drivers sine I was wanting the gold colored one, but as soon as I see them I will get them ordered. The bracing is inside, but not mounted yet due to its close proximity to the driver. I wanted to get the driver mounted before I fix them in place. Thanks for all the suggestions I will keep you posted on how they sound once they are playing.

Sorry for the crappy cell phone picture, my good camera is under my desk at work...

Thanks,
Adam