Spawn of Frugel-Horn

[brucedal1]

I just can't belive how you guys (scottmoose and GM) are able to hear my poorly described problems and immediately identify the cause. I definately was the bookshelf amp. I borrowed a heavier duty amp from my brother and it was unbeleiveable the difference that it made!!
These things are powerful!! Even my girlfriend likes the sound. Plenty loud enough to annoy all in the house But, as I won't be able to use this amp forever, I could get my own pro-amp for it, or save up for a tube amp.
BTW, this is as off topic as I'll take this What amp might work well for Bruce using a Bruce!

Thanks,
Bruce

[planet10]

Originally posted by brucedal1
What amp might work well for Bruce using a Bruce!

Unless you listen thunderously loud one of the small digital amps might well be one of the best, off-the-shelf solutions. Otherwise a Frugal-phile(tm) build of an RH84 or an El Cheapo... of course if you have more budget a lot more options become available.

I understand this one is decent

http://www.trendsaudio.com/EN/Product/TA-10_desc.htm

http://www.6moons.com/audioreviews/trends/ta10.html

dave

[GM]

Originally posted by brucedal1
I just can't belive how you guys (scottmoose and GM) are able to hear my poorly described problems and immediately identify the cause.

I could get my own pro-amp for it, or save up for a tube amp.
BTW, this is as off topic as I'll take this What amp might work well for Bruce using a Bruce!

Greets!

Yours was a common newbie problem.........

Unless it's a Crown studio/recording series or similar ($$$), steer clear of prosound amps for wide BW use as they aren't designed with high sound quality (SQ) in mind.

Since you're having to use considerable series resistance to flatten its response, you need an amp with a power rating at a nominal impedance high enough to handle it, or ~16 ohms in your case if you don't want it to possibly 'lay down' due to not enough voltage swing when there's significant LF content in the recording. This makes any of the chip amps I've seen specs of suspect IMO, so Caveat Emptor.

GM

[Scottmoose]

I reckon he might be OK Greg -a fair proportion of the series resistance is probably due to the lack of amp adjustment to Qt (I'm learning... ). Most T-amps have a relatively low DF IIRC, so the T-amp's lack of voltage swinging ability might not be too much of a problem. I'm no expert though as you know, so please put me straight if I'm off the mark on this.

[brucedal1]

The 8 ohms was just the smallest resistor I had on hand. (and the only one not 1/4 watt)

I hardly know anything!! I just read what you guys "in the know" say and do it. The theory seems to stick and I try to put it into my own practice (like my failed "cheapo" bibs) then, I just say "BAH, I'll use the know quantity and tweak it if necessary" So from my end a big thanks to all those who know and share!

Bruce

[samplesj]

Anyone built a Sachiko so far?

I'm looking for a very high eff speaker so the 8" driver stood out. I know some of the other 8" drivers don't HAVE to have a tweeter, but I want sparkle so I'm already commited to one anyway (my main system uses ribbons so I'm afraid I'd miss their extension). I've also read the sigmas have a very good midrange so that is why I was considering the FE208EZ first. Of course I'm open to other driver suggestions too.

From what I interpreted earlier it sounds like the Sachiko is a better fit for that driver because Bruce is more of a BR design so it wants a higher qts.

Any modifications needed to use that driver in that cabinet?

Where is the best place to mount the tweeter. Can't use the top like the stock cabinets. Attach it to the side or steal a bit of the baffle? If you used the baffle would the tweeter take enough airspace to need to tweak those dimensions?

Thanks for the detailed plans! The cut plan is a great touch.

Jeremy

[planet10]

Originally posted by samplesj
Where is the best place to mount the tweeter.

I'd look at using one of the baffle mounted tweeters -- we are playing with FT17 ATM.

dave

[samplesj]

Originally posted by planet10

I'd look at using one of the baffle mounted tweeters -- we are playing with FT17 ATM.

Thanks!

I can see how that is much easier than dealing with the pod style. The FT17 isn't as much either. It looks to be a good match in efficency. I'm sure with a bit of playing around I can find the right crossover cap value. I know this is the Full Range forum so that is heresy, but I just want high eff.

It won't fit directly above the bigger driver, but if I put it diagonally to one side it should fix fine.

After calculating the driver baffle area vs the area the tweeter takes up I see its only a bit over 1% of the space so I guess its just noise.

Its a shame the AC ribbons are so much $ and so much bigger.

[planet10]

Originally posted by samplesj
Its a shame the AC ribbons are so much $ and so much bigger.

And a good chance they won't work as well (i have a pair of those too)

dave

[badman]

Originally posted by Scottmoose
I reckon he might be OK Greg -a fair proportion of the series resistance is probably due to the lack of amp adjustment to Qt (I'm learning... ). Most T-amps have a relatively low DF IIRC, so the T-amp's lack of voltage swinging ability might not be too much of a problem. I'm no expert though as you know, so please put me straight if I'm off the mark on this.

The damping factor of your average class D amp is pretty decent, but decreases with increasing frequency due to the typical LC network for keeping RF out of your speaker. Funny... most speakers have increasing impedance with increasing frequency anyway.... perhaps this actually leads to a more consistent damping factor over the load vs. a frequency constant DF.....